1fbf59bc9STejun Heo /* 288999a89STejun Heo * mm/percpu.c - percpu memory allocator 3fbf59bc9STejun Heo * 4fbf59bc9STejun Heo * Copyright (C) 2009 SUSE Linux Products GmbH 5fbf59bc9STejun Heo * Copyright (C) 2009 Tejun Heo <tj@kernel.org> 6fbf59bc9STejun Heo * 79c015162SDennis Zhou (Facebook) * This file is released under the GPLv2 license. 8fbf59bc9STejun Heo * 99c015162SDennis Zhou (Facebook) * The percpu allocator handles both static and dynamic areas. Percpu 109c015162SDennis Zhou (Facebook) * areas are allocated in chunks which are divided into units. There is 119c015162SDennis Zhou (Facebook) * a 1-to-1 mapping for units to possible cpus. These units are grouped 129c015162SDennis Zhou (Facebook) * based on NUMA properties of the machine. 13fbf59bc9STejun Heo * 14fbf59bc9STejun Heo * c0 c1 c2 15fbf59bc9STejun Heo * ------------------- ------------------- ------------ 16fbf59bc9STejun Heo * | u0 | u1 | u2 | u3 | | u0 | u1 | u2 | u3 | | u0 | u1 | u 17fbf59bc9STejun Heo * ------------------- ...... ------------------- .... ------------ 18fbf59bc9STejun Heo * 199c015162SDennis Zhou (Facebook) * Allocation is done by offsets into a unit's address space. Ie., an 209c015162SDennis Zhou (Facebook) * area of 512 bytes at 6k in c1 occupies 512 bytes at 6k in c1:u0, 219c015162SDennis Zhou (Facebook) * c1:u1, c1:u2, etc. On NUMA machines, the mapping may be non-linear 229c015162SDennis Zhou (Facebook) * and even sparse. Access is handled by configuring percpu base 239c015162SDennis Zhou (Facebook) * registers according to the cpu to unit mappings and offsetting the 249c015162SDennis Zhou (Facebook) * base address using pcpu_unit_size. 25fbf59bc9STejun Heo * 269c015162SDennis Zhou (Facebook) * There is special consideration for the first chunk which must handle 279c015162SDennis Zhou (Facebook) * the static percpu variables in the kernel image as allocation services 289c015162SDennis Zhou (Facebook) * are not online yet. In short, the first chunk is structure like so: 299c015162SDennis Zhou (Facebook) * 309c015162SDennis Zhou (Facebook) * <Static | [Reserved] | Dynamic> 319c015162SDennis Zhou (Facebook) * 329c015162SDennis Zhou (Facebook) * The static data is copied from the original section managed by the 339c015162SDennis Zhou (Facebook) * linker. The reserved section, if non-zero, primarily manages static 349c015162SDennis Zhou (Facebook) * percpu variables from kernel modules. Finally, the dynamic section 359c015162SDennis Zhou (Facebook) * takes care of normal allocations. 36fbf59bc9STejun Heo * 37fbf59bc9STejun Heo * Allocation state in each chunk is kept using an array of integers 38fbf59bc9STejun Heo * on chunk->map. A positive value in the map represents a free 39fbf59bc9STejun Heo * region and negative allocated. Allocation inside a chunk is done 40fbf59bc9STejun Heo * by scanning this map sequentially and serving the first matching 41fbf59bc9STejun Heo * entry. This is mostly copied from the percpu_modalloc() allocator. 42e1b9aa3fSChristoph Lameter * Chunks can be determined from the address using the index field 43e1b9aa3fSChristoph Lameter * in the page struct. The index field contains a pointer to the chunk. 44fbf59bc9STejun Heo * 459c015162SDennis Zhou (Facebook) * These chunks are organized into lists according to free_size and 469c015162SDennis Zhou (Facebook) * tries to allocate from the fullest chunk first. Each chunk maintains 479c015162SDennis Zhou (Facebook) * a maximum contiguous area size hint which is guaranteed to be equal 489c015162SDennis Zhou (Facebook) * to or larger than the maximum contiguous area in the chunk. This 499c015162SDennis Zhou (Facebook) * helps prevent the allocator from iterating over chunks unnecessarily. 509c015162SDennis Zhou (Facebook) * 514091fb95SMasahiro Yamada * To use this allocator, arch code should do the following: 52fbf59bc9STejun Heo * 53fbf59bc9STejun Heo * - define __addr_to_pcpu_ptr() and __pcpu_ptr_to_addr() to translate 54e0100983STejun Heo * regular address to percpu pointer and back if they need to be 55e0100983STejun Heo * different from the default 56fbf59bc9STejun Heo * 578d408b4bSTejun Heo * - use pcpu_setup_first_chunk() during percpu area initialization to 588d408b4bSTejun Heo * setup the first chunk containing the kernel static percpu area 59fbf59bc9STejun Heo */ 60fbf59bc9STejun Heo 61870d4b12SJoe Perches #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 62870d4b12SJoe Perches 63fbf59bc9STejun Heo #include <linux/bitmap.h> 64fbf59bc9STejun Heo #include <linux/bootmem.h> 65fd1e8a1fSTejun Heo #include <linux/err.h> 66fbf59bc9STejun Heo #include <linux/list.h> 67a530b795STejun Heo #include <linux/log2.h> 68fbf59bc9STejun Heo #include <linux/mm.h> 69fbf59bc9STejun Heo #include <linux/module.h> 70fbf59bc9STejun Heo #include <linux/mutex.h> 71fbf59bc9STejun Heo #include <linux/percpu.h> 72fbf59bc9STejun Heo #include <linux/pfn.h> 73fbf59bc9STejun Heo #include <linux/slab.h> 74ccea34b5STejun Heo #include <linux/spinlock.h> 75fbf59bc9STejun Heo #include <linux/vmalloc.h> 76a56dbddfSTejun Heo #include <linux/workqueue.h> 77f528f0b8SCatalin Marinas #include <linux/kmemleak.h> 78fbf59bc9STejun Heo 79fbf59bc9STejun Heo #include <asm/cacheflush.h> 80e0100983STejun Heo #include <asm/sections.h> 81fbf59bc9STejun Heo #include <asm/tlbflush.h> 823b034b0dSVivek Goyal #include <asm/io.h> 83fbf59bc9STejun Heo 84df95e795SDennis Zhou #define CREATE_TRACE_POINTS 85df95e795SDennis Zhou #include <trace/events/percpu.h> 86df95e795SDennis Zhou 878fa3ed80SDennis Zhou #include "percpu-internal.h" 888fa3ed80SDennis Zhou 89fbf59bc9STejun Heo #define PCPU_SLOT_BASE_SHIFT 5 /* 1-31 shares the same slot */ 90fbf59bc9STejun Heo #define PCPU_DFL_MAP_ALLOC 16 /* start a map with 16 ents */ 919c824b6aSTejun Heo #define PCPU_ATOMIC_MAP_MARGIN_LOW 32 929c824b6aSTejun Heo #define PCPU_ATOMIC_MAP_MARGIN_HIGH 64 931a4d7607STejun Heo #define PCPU_EMPTY_POP_PAGES_LOW 2 941a4d7607STejun Heo #define PCPU_EMPTY_POP_PAGES_HIGH 4 95fbf59bc9STejun Heo 96bbddff05STejun Heo #ifdef CONFIG_SMP 97e0100983STejun Heo /* default addr <-> pcpu_ptr mapping, override in asm/percpu.h if necessary */ 98e0100983STejun Heo #ifndef __addr_to_pcpu_ptr 99e0100983STejun Heo #define __addr_to_pcpu_ptr(addr) \ 10043cf38ebSTejun Heo (void __percpu *)((unsigned long)(addr) - \ 10143cf38ebSTejun Heo (unsigned long)pcpu_base_addr + \ 10243cf38ebSTejun Heo (unsigned long)__per_cpu_start) 103e0100983STejun Heo #endif 104e0100983STejun Heo #ifndef __pcpu_ptr_to_addr 105e0100983STejun Heo #define __pcpu_ptr_to_addr(ptr) \ 10643cf38ebSTejun Heo (void __force *)((unsigned long)(ptr) + \ 10743cf38ebSTejun Heo (unsigned long)pcpu_base_addr - \ 10843cf38ebSTejun Heo (unsigned long)__per_cpu_start) 109e0100983STejun Heo #endif 110bbddff05STejun Heo #else /* CONFIG_SMP */ 111bbddff05STejun Heo /* on UP, it's always identity mapped */ 112bbddff05STejun Heo #define __addr_to_pcpu_ptr(addr) (void __percpu *)(addr) 113bbddff05STejun Heo #define __pcpu_ptr_to_addr(ptr) (void __force *)(ptr) 114bbddff05STejun Heo #endif /* CONFIG_SMP */ 115e0100983STejun Heo 1161328710bSDaniel Micay static int pcpu_unit_pages __ro_after_init; 1171328710bSDaniel Micay static int pcpu_unit_size __ro_after_init; 1181328710bSDaniel Micay static int pcpu_nr_units __ro_after_init; 1191328710bSDaniel Micay static int pcpu_atom_size __ro_after_init; 1208fa3ed80SDennis Zhou int pcpu_nr_slots __ro_after_init; 1211328710bSDaniel Micay static size_t pcpu_chunk_struct_size __ro_after_init; 122fbf59bc9STejun Heo 123a855b84cSTejun Heo /* cpus with the lowest and highest unit addresses */ 1241328710bSDaniel Micay static unsigned int pcpu_low_unit_cpu __ro_after_init; 1251328710bSDaniel Micay static unsigned int pcpu_high_unit_cpu __ro_after_init; 1262f39e637STejun Heo 127fbf59bc9STejun Heo /* the address of the first chunk which starts with the kernel static area */ 1281328710bSDaniel Micay void *pcpu_base_addr __ro_after_init; 129fbf59bc9STejun Heo EXPORT_SYMBOL_GPL(pcpu_base_addr); 130fbf59bc9STejun Heo 1311328710bSDaniel Micay static const int *pcpu_unit_map __ro_after_init; /* cpu -> unit */ 1321328710bSDaniel Micay const unsigned long *pcpu_unit_offsets __ro_after_init; /* cpu -> unit offset */ 1332f39e637STejun Heo 1346563297cSTejun Heo /* group information, used for vm allocation */ 1351328710bSDaniel Micay static int pcpu_nr_groups __ro_after_init; 1361328710bSDaniel Micay static const unsigned long *pcpu_group_offsets __ro_after_init; 1371328710bSDaniel Micay static const size_t *pcpu_group_sizes __ro_after_init; 1386563297cSTejun Heo 139ae9e6bc9STejun Heo /* 140ae9e6bc9STejun Heo * The first chunk which always exists. Note that unlike other 141ae9e6bc9STejun Heo * chunks, this one can be allocated and mapped in several different 142ae9e6bc9STejun Heo * ways and thus often doesn't live in the vmalloc area. 143ae9e6bc9STejun Heo */ 1448fa3ed80SDennis Zhou struct pcpu_chunk *pcpu_first_chunk __ro_after_init; 145ae9e6bc9STejun Heo 146ae9e6bc9STejun Heo /* 147ae9e6bc9STejun Heo * Optional reserved chunk. This chunk reserves part of the first 148e2266705SDennis Zhou (Facebook) * chunk and serves it for reserved allocations. When the reserved 149e2266705SDennis Zhou (Facebook) * region doesn't exist, the following variable is NULL. 150ae9e6bc9STejun Heo */ 1518fa3ed80SDennis Zhou struct pcpu_chunk *pcpu_reserved_chunk __ro_after_init; 152edcb4639STejun Heo 1538fa3ed80SDennis Zhou DEFINE_SPINLOCK(pcpu_lock); /* all internal data structures */ 1546710e594STejun Heo static DEFINE_MUTEX(pcpu_alloc_mutex); /* chunk create/destroy, [de]pop, map ext */ 155fbf59bc9STejun Heo 1568fa3ed80SDennis Zhou struct list_head *pcpu_slot __ro_after_init; /* chunk list slots */ 157fbf59bc9STejun Heo 1584f996e23STejun Heo /* chunks which need their map areas extended, protected by pcpu_lock */ 1594f996e23STejun Heo static LIST_HEAD(pcpu_map_extend_chunks); 1604f996e23STejun Heo 161b539b87fSTejun Heo /* 162b539b87fSTejun Heo * The number of empty populated pages, protected by pcpu_lock. The 163b539b87fSTejun Heo * reserved chunk doesn't contribute to the count. 164b539b87fSTejun Heo */ 1656b9b6f39SDennis Zhou (Facebook) int pcpu_nr_empty_pop_pages; 166b539b87fSTejun Heo 1671a4d7607STejun Heo /* 1681a4d7607STejun Heo * Balance work is used to populate or destroy chunks asynchronously. We 1691a4d7607STejun Heo * try to keep the number of populated free pages between 1701a4d7607STejun Heo * PCPU_EMPTY_POP_PAGES_LOW and HIGH for atomic allocations and at most one 1711a4d7607STejun Heo * empty chunk. 1721a4d7607STejun Heo */ 173fe6bd8c3STejun Heo static void pcpu_balance_workfn(struct work_struct *work); 174fe6bd8c3STejun Heo static DECLARE_WORK(pcpu_balance_work, pcpu_balance_workfn); 1751a4d7607STejun Heo static bool pcpu_async_enabled __read_mostly; 1761a4d7607STejun Heo static bool pcpu_atomic_alloc_failed; 1771a4d7607STejun Heo 1781a4d7607STejun Heo static void pcpu_schedule_balance_work(void) 1791a4d7607STejun Heo { 1801a4d7607STejun Heo if (pcpu_async_enabled) 1811a4d7607STejun Heo schedule_work(&pcpu_balance_work); 1821a4d7607STejun Heo } 183a56dbddfSTejun Heo 184c0ebfdc3SDennis Zhou (Facebook) /** 185560f2c23SDennis Zhou (Facebook) * pcpu_addr_in_chunk - check if the address is served from this chunk 186560f2c23SDennis Zhou (Facebook) * @chunk: chunk of interest 187560f2c23SDennis Zhou (Facebook) * @addr: percpu address 188c0ebfdc3SDennis Zhou (Facebook) * 189c0ebfdc3SDennis Zhou (Facebook) * RETURNS: 190560f2c23SDennis Zhou (Facebook) * True if the address is served from this chunk. 191c0ebfdc3SDennis Zhou (Facebook) */ 192560f2c23SDennis Zhou (Facebook) static bool pcpu_addr_in_chunk(struct pcpu_chunk *chunk, void *addr) 193020ec653STejun Heo { 194c0ebfdc3SDennis Zhou (Facebook) void *start_addr, *end_addr; 195020ec653STejun Heo 196560f2c23SDennis Zhou (Facebook) if (!chunk) 197c0ebfdc3SDennis Zhou (Facebook) return false; 198c0ebfdc3SDennis Zhou (Facebook) 199560f2c23SDennis Zhou (Facebook) start_addr = chunk->base_addr + chunk->start_offset; 200560f2c23SDennis Zhou (Facebook) end_addr = chunk->base_addr + chunk->nr_pages * PAGE_SIZE - 201560f2c23SDennis Zhou (Facebook) chunk->end_offset; 202c0ebfdc3SDennis Zhou (Facebook) 203c0ebfdc3SDennis Zhou (Facebook) return addr >= start_addr && addr < end_addr; 204020ec653STejun Heo } 205020ec653STejun Heo 206d9b55eebSTejun Heo static int __pcpu_size_to_slot(int size) 207fbf59bc9STejun Heo { 208cae3aeb8STejun Heo int highbit = fls(size); /* size is in bytes */ 209fbf59bc9STejun Heo return max(highbit - PCPU_SLOT_BASE_SHIFT + 2, 1); 210fbf59bc9STejun Heo } 211fbf59bc9STejun Heo 212d9b55eebSTejun Heo static int pcpu_size_to_slot(int size) 213d9b55eebSTejun Heo { 214d9b55eebSTejun Heo if (size == pcpu_unit_size) 215d9b55eebSTejun Heo return pcpu_nr_slots - 1; 216d9b55eebSTejun Heo return __pcpu_size_to_slot(size); 217d9b55eebSTejun Heo } 218d9b55eebSTejun Heo 219fbf59bc9STejun Heo static int pcpu_chunk_slot(const struct pcpu_chunk *chunk) 220fbf59bc9STejun Heo { 221fbf59bc9STejun Heo if (chunk->free_size < sizeof(int) || chunk->contig_hint < sizeof(int)) 222fbf59bc9STejun Heo return 0; 223fbf59bc9STejun Heo 224fbf59bc9STejun Heo return pcpu_size_to_slot(chunk->free_size); 225fbf59bc9STejun Heo } 226fbf59bc9STejun Heo 22788999a89STejun Heo /* set the pointer to a chunk in a page struct */ 22888999a89STejun Heo static void pcpu_set_page_chunk(struct page *page, struct pcpu_chunk *pcpu) 22988999a89STejun Heo { 23088999a89STejun Heo page->index = (unsigned long)pcpu; 23188999a89STejun Heo } 23288999a89STejun Heo 23388999a89STejun Heo /* obtain pointer to a chunk from a page struct */ 23488999a89STejun Heo static struct pcpu_chunk *pcpu_get_page_chunk(struct page *page) 23588999a89STejun Heo { 23688999a89STejun Heo return (struct pcpu_chunk *)page->index; 23788999a89STejun Heo } 23888999a89STejun Heo 23988999a89STejun Heo static int __maybe_unused pcpu_page_idx(unsigned int cpu, int page_idx) 240fbf59bc9STejun Heo { 2412f39e637STejun Heo return pcpu_unit_map[cpu] * pcpu_unit_pages + page_idx; 242fbf59bc9STejun Heo } 243fbf59bc9STejun Heo 244c0ebfdc3SDennis Zhou (Facebook) static unsigned long pcpu_unit_page_offset(unsigned int cpu, int page_idx) 245c0ebfdc3SDennis Zhou (Facebook) { 246c0ebfdc3SDennis Zhou (Facebook) return pcpu_unit_offsets[cpu] + (page_idx << PAGE_SHIFT); 247c0ebfdc3SDennis Zhou (Facebook) } 248c0ebfdc3SDennis Zhou (Facebook) 2499983b6f0STejun Heo static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk, 250fbf59bc9STejun Heo unsigned int cpu, int page_idx) 251fbf59bc9STejun Heo { 252c0ebfdc3SDennis Zhou (Facebook) return (unsigned long)chunk->base_addr + 253c0ebfdc3SDennis Zhou (Facebook) pcpu_unit_page_offset(cpu, page_idx); 254fbf59bc9STejun Heo } 255fbf59bc9STejun Heo 25688999a89STejun Heo static void __maybe_unused pcpu_next_unpop(struct pcpu_chunk *chunk, 25788999a89STejun Heo int *rs, int *re, int end) 258ce3141a2STejun Heo { 259ce3141a2STejun Heo *rs = find_next_zero_bit(chunk->populated, end, *rs); 260ce3141a2STejun Heo *re = find_next_bit(chunk->populated, end, *rs + 1); 261ce3141a2STejun Heo } 262ce3141a2STejun Heo 26388999a89STejun Heo static void __maybe_unused pcpu_next_pop(struct pcpu_chunk *chunk, 26488999a89STejun Heo int *rs, int *re, int end) 265ce3141a2STejun Heo { 266ce3141a2STejun Heo *rs = find_next_bit(chunk->populated, end, *rs); 267ce3141a2STejun Heo *re = find_next_zero_bit(chunk->populated, end, *rs + 1); 268ce3141a2STejun Heo } 269ce3141a2STejun Heo 270ce3141a2STejun Heo /* 271ce3141a2STejun Heo * (Un)populated page region iterators. Iterate over (un)populated 272b595076aSUwe Kleine-König * page regions between @start and @end in @chunk. @rs and @re should 273ce3141a2STejun Heo * be integer variables and will be set to start and end page index of 274ce3141a2STejun Heo * the current region. 275ce3141a2STejun Heo */ 276ce3141a2STejun Heo #define pcpu_for_each_unpop_region(chunk, rs, re, start, end) \ 277ce3141a2STejun Heo for ((rs) = (start), pcpu_next_unpop((chunk), &(rs), &(re), (end)); \ 278ce3141a2STejun Heo (rs) < (re); \ 279ce3141a2STejun Heo (rs) = (re) + 1, pcpu_next_unpop((chunk), &(rs), &(re), (end))) 280ce3141a2STejun Heo 281ce3141a2STejun Heo #define pcpu_for_each_pop_region(chunk, rs, re, start, end) \ 282ce3141a2STejun Heo for ((rs) = (start), pcpu_next_pop((chunk), &(rs), &(re), (end)); \ 283ce3141a2STejun Heo (rs) < (re); \ 284ce3141a2STejun Heo (rs) = (re) + 1, pcpu_next_pop((chunk), &(rs), &(re), (end))) 285ce3141a2STejun Heo 286fbf59bc9STejun Heo /** 28790459ce0SBob Liu * pcpu_mem_zalloc - allocate memory 2881880d93bSTejun Heo * @size: bytes to allocate 289fbf59bc9STejun Heo * 2901880d93bSTejun Heo * Allocate @size bytes. If @size is smaller than PAGE_SIZE, 29190459ce0SBob Liu * kzalloc() is used; otherwise, vzalloc() is used. The returned 2921880d93bSTejun Heo * memory is always zeroed. 293fbf59bc9STejun Heo * 294ccea34b5STejun Heo * CONTEXT: 295ccea34b5STejun Heo * Does GFP_KERNEL allocation. 296ccea34b5STejun Heo * 297fbf59bc9STejun Heo * RETURNS: 2981880d93bSTejun Heo * Pointer to the allocated area on success, NULL on failure. 299fbf59bc9STejun Heo */ 30090459ce0SBob Liu static void *pcpu_mem_zalloc(size_t size) 301fbf59bc9STejun Heo { 302099a19d9STejun Heo if (WARN_ON_ONCE(!slab_is_available())) 303099a19d9STejun Heo return NULL; 304099a19d9STejun Heo 305fbf59bc9STejun Heo if (size <= PAGE_SIZE) 3061880d93bSTejun Heo return kzalloc(size, GFP_KERNEL); 3077af4c093SJesper Juhl else 3087af4c093SJesper Juhl return vzalloc(size); 3091880d93bSTejun Heo } 310fbf59bc9STejun Heo 3111880d93bSTejun Heo /** 3121880d93bSTejun Heo * pcpu_mem_free - free memory 3131880d93bSTejun Heo * @ptr: memory to free 3141880d93bSTejun Heo * 31590459ce0SBob Liu * Free @ptr. @ptr should have been allocated using pcpu_mem_zalloc(). 3161880d93bSTejun Heo */ 3171d5cfdb0STetsuo Handa static void pcpu_mem_free(void *ptr) 3181880d93bSTejun Heo { 3191d5cfdb0STetsuo Handa kvfree(ptr); 320fbf59bc9STejun Heo } 321fbf59bc9STejun Heo 322fbf59bc9STejun Heo /** 323b539b87fSTejun Heo * pcpu_count_occupied_pages - count the number of pages an area occupies 324b539b87fSTejun Heo * @chunk: chunk of interest 325b539b87fSTejun Heo * @i: index of the area in question 326b539b87fSTejun Heo * 327b539b87fSTejun Heo * Count the number of pages chunk's @i'th area occupies. When the area's 328b539b87fSTejun Heo * start and/or end address isn't aligned to page boundary, the straddled 329b539b87fSTejun Heo * page is included in the count iff the rest of the page is free. 330b539b87fSTejun Heo */ 331b539b87fSTejun Heo static int pcpu_count_occupied_pages(struct pcpu_chunk *chunk, int i) 332b539b87fSTejun Heo { 333b539b87fSTejun Heo int off = chunk->map[i] & ~1; 334b539b87fSTejun Heo int end = chunk->map[i + 1] & ~1; 335b539b87fSTejun Heo 336b539b87fSTejun Heo if (!PAGE_ALIGNED(off) && i > 0) { 337b539b87fSTejun Heo int prev = chunk->map[i - 1]; 338b539b87fSTejun Heo 339b539b87fSTejun Heo if (!(prev & 1) && prev <= round_down(off, PAGE_SIZE)) 340b539b87fSTejun Heo off = round_down(off, PAGE_SIZE); 341b539b87fSTejun Heo } 342b539b87fSTejun Heo 343b539b87fSTejun Heo if (!PAGE_ALIGNED(end) && i + 1 < chunk->map_used) { 344b539b87fSTejun Heo int next = chunk->map[i + 1]; 345b539b87fSTejun Heo int nend = chunk->map[i + 2] & ~1; 346b539b87fSTejun Heo 347b539b87fSTejun Heo if (!(next & 1) && nend >= round_up(end, PAGE_SIZE)) 348b539b87fSTejun Heo end = round_up(end, PAGE_SIZE); 349b539b87fSTejun Heo } 350b539b87fSTejun Heo 351b539b87fSTejun Heo return max_t(int, PFN_DOWN(end) - PFN_UP(off), 0); 352b539b87fSTejun Heo } 353b539b87fSTejun Heo 354b539b87fSTejun Heo /** 355fbf59bc9STejun Heo * pcpu_chunk_relocate - put chunk in the appropriate chunk slot 356fbf59bc9STejun Heo * @chunk: chunk of interest 357fbf59bc9STejun Heo * @oslot: the previous slot it was on 358fbf59bc9STejun Heo * 359fbf59bc9STejun Heo * This function is called after an allocation or free changed @chunk. 360fbf59bc9STejun Heo * New slot according to the changed state is determined and @chunk is 361edcb4639STejun Heo * moved to the slot. Note that the reserved chunk is never put on 362edcb4639STejun Heo * chunk slots. 363ccea34b5STejun Heo * 364ccea34b5STejun Heo * CONTEXT: 365ccea34b5STejun Heo * pcpu_lock. 366fbf59bc9STejun Heo */ 367fbf59bc9STejun Heo static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot) 368fbf59bc9STejun Heo { 369fbf59bc9STejun Heo int nslot = pcpu_chunk_slot(chunk); 370fbf59bc9STejun Heo 371edcb4639STejun Heo if (chunk != pcpu_reserved_chunk && oslot != nslot) { 372fbf59bc9STejun Heo if (oslot < nslot) 373fbf59bc9STejun Heo list_move(&chunk->list, &pcpu_slot[nslot]); 374fbf59bc9STejun Heo else 375fbf59bc9STejun Heo list_move_tail(&chunk->list, &pcpu_slot[nslot]); 376fbf59bc9STejun Heo } 377fbf59bc9STejun Heo } 378fbf59bc9STejun Heo 379fbf59bc9STejun Heo /** 380833af842STejun Heo * pcpu_need_to_extend - determine whether chunk area map needs to be extended 381833af842STejun Heo * @chunk: chunk of interest 3829c824b6aSTejun Heo * @is_atomic: the allocation context 3839f7dcf22STejun Heo * 3849c824b6aSTejun Heo * Determine whether area map of @chunk needs to be extended. If 3859c824b6aSTejun Heo * @is_atomic, only the amount necessary for a new allocation is 3869c824b6aSTejun Heo * considered; however, async extension is scheduled if the left amount is 3879c824b6aSTejun Heo * low. If !@is_atomic, it aims for more empty space. Combined, this 3889c824b6aSTejun Heo * ensures that the map is likely to have enough available space to 3899c824b6aSTejun Heo * accomodate atomic allocations which can't extend maps directly. 3909f7dcf22STejun Heo * 391ccea34b5STejun Heo * CONTEXT: 392833af842STejun Heo * pcpu_lock. 393ccea34b5STejun Heo * 3949f7dcf22STejun Heo * RETURNS: 395833af842STejun Heo * New target map allocation length if extension is necessary, 0 396833af842STejun Heo * otherwise. 3979f7dcf22STejun Heo */ 3989c824b6aSTejun Heo static int pcpu_need_to_extend(struct pcpu_chunk *chunk, bool is_atomic) 3999f7dcf22STejun Heo { 4009c824b6aSTejun Heo int margin, new_alloc; 4019f7dcf22STejun Heo 4024f996e23STejun Heo lockdep_assert_held(&pcpu_lock); 4034f996e23STejun Heo 4049c824b6aSTejun Heo if (is_atomic) { 4059c824b6aSTejun Heo margin = 3; 4069c824b6aSTejun Heo 4079c824b6aSTejun Heo if (chunk->map_alloc < 4084f996e23STejun Heo chunk->map_used + PCPU_ATOMIC_MAP_MARGIN_LOW) { 4094f996e23STejun Heo if (list_empty(&chunk->map_extend_list)) { 4104f996e23STejun Heo list_add_tail(&chunk->map_extend_list, 4114f996e23STejun Heo &pcpu_map_extend_chunks); 4124f996e23STejun Heo pcpu_schedule_balance_work(); 4134f996e23STejun Heo } 4144f996e23STejun Heo } 4159c824b6aSTejun Heo } else { 4169c824b6aSTejun Heo margin = PCPU_ATOMIC_MAP_MARGIN_HIGH; 4179c824b6aSTejun Heo } 4189c824b6aSTejun Heo 4199c824b6aSTejun Heo if (chunk->map_alloc >= chunk->map_used + margin) 4209f7dcf22STejun Heo return 0; 4219f7dcf22STejun Heo 4229f7dcf22STejun Heo new_alloc = PCPU_DFL_MAP_ALLOC; 4239c824b6aSTejun Heo while (new_alloc < chunk->map_used + margin) 4249f7dcf22STejun Heo new_alloc *= 2; 4259f7dcf22STejun Heo 426833af842STejun Heo return new_alloc; 427ccea34b5STejun Heo } 428ccea34b5STejun Heo 429833af842STejun Heo /** 430833af842STejun Heo * pcpu_extend_area_map - extend area map of a chunk 431833af842STejun Heo * @chunk: chunk of interest 432833af842STejun Heo * @new_alloc: new target allocation length of the area map 433833af842STejun Heo * 434833af842STejun Heo * Extend area map of @chunk to have @new_alloc entries. 435833af842STejun Heo * 436833af842STejun Heo * CONTEXT: 437833af842STejun Heo * Does GFP_KERNEL allocation. Grabs and releases pcpu_lock. 438833af842STejun Heo * 439833af842STejun Heo * RETURNS: 440833af842STejun Heo * 0 on success, -errno on failure. 441ccea34b5STejun Heo */ 442833af842STejun Heo static int pcpu_extend_area_map(struct pcpu_chunk *chunk, int new_alloc) 443833af842STejun Heo { 444833af842STejun Heo int *old = NULL, *new = NULL; 445833af842STejun Heo size_t old_size = 0, new_size = new_alloc * sizeof(new[0]); 446833af842STejun Heo unsigned long flags; 4479f7dcf22STejun Heo 4486710e594STejun Heo lockdep_assert_held(&pcpu_alloc_mutex); 4496710e594STejun Heo 45090459ce0SBob Liu new = pcpu_mem_zalloc(new_size); 451833af842STejun Heo if (!new) 452833af842STejun Heo return -ENOMEM; 453833af842STejun Heo 454833af842STejun Heo /* acquire pcpu_lock and switch to new area map */ 455833af842STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 456833af842STejun Heo 457833af842STejun Heo if (new_alloc <= chunk->map_alloc) 458833af842STejun Heo goto out_unlock; 459833af842STejun Heo 460833af842STejun Heo old_size = chunk->map_alloc * sizeof(chunk->map[0]); 461a002d148SHuang Shijie old = chunk->map; 462a002d148SHuang Shijie 463a002d148SHuang Shijie memcpy(new, old, old_size); 4649f7dcf22STejun Heo 4659f7dcf22STejun Heo chunk->map_alloc = new_alloc; 4669f7dcf22STejun Heo chunk->map = new; 467833af842STejun Heo new = NULL; 468833af842STejun Heo 469833af842STejun Heo out_unlock: 470833af842STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 471833af842STejun Heo 472833af842STejun Heo /* 473833af842STejun Heo * pcpu_mem_free() might end up calling vfree() which uses 474833af842STejun Heo * IRQ-unsafe lock and thus can't be called under pcpu_lock. 475833af842STejun Heo */ 4761d5cfdb0STetsuo Handa pcpu_mem_free(old); 4771d5cfdb0STetsuo Handa pcpu_mem_free(new); 478833af842STejun Heo 4799f7dcf22STejun Heo return 0; 4809f7dcf22STejun Heo } 4819f7dcf22STejun Heo 4829f7dcf22STejun Heo /** 483a16037c8STejun Heo * pcpu_fit_in_area - try to fit the requested allocation in a candidate area 484a16037c8STejun Heo * @chunk: chunk the candidate area belongs to 485a16037c8STejun Heo * @off: the offset to the start of the candidate area 486a16037c8STejun Heo * @this_size: the size of the candidate area 487a16037c8STejun Heo * @size: the size of the target allocation 488a16037c8STejun Heo * @align: the alignment of the target allocation 489a16037c8STejun Heo * @pop_only: only allocate from already populated region 490a16037c8STejun Heo * 491a16037c8STejun Heo * We're trying to allocate @size bytes aligned at @align. @chunk's area 492a16037c8STejun Heo * at @off sized @this_size is a candidate. This function determines 493a16037c8STejun Heo * whether the target allocation fits in the candidate area and returns the 494a16037c8STejun Heo * number of bytes to pad after @off. If the target area doesn't fit, -1 495a16037c8STejun Heo * is returned. 496a16037c8STejun Heo * 497a16037c8STejun Heo * If @pop_only is %true, this function only considers the already 498a16037c8STejun Heo * populated part of the candidate area. 499a16037c8STejun Heo */ 500a16037c8STejun Heo static int pcpu_fit_in_area(struct pcpu_chunk *chunk, int off, int this_size, 501a16037c8STejun Heo int size, int align, bool pop_only) 502a16037c8STejun Heo { 503a16037c8STejun Heo int cand_off = off; 504a16037c8STejun Heo 505a16037c8STejun Heo while (true) { 506a16037c8STejun Heo int head = ALIGN(cand_off, align) - off; 507a16037c8STejun Heo int page_start, page_end, rs, re; 508a16037c8STejun Heo 509a16037c8STejun Heo if (this_size < head + size) 510a16037c8STejun Heo return -1; 511a16037c8STejun Heo 512a16037c8STejun Heo if (!pop_only) 513a16037c8STejun Heo return head; 514a16037c8STejun Heo 515a16037c8STejun Heo /* 516a16037c8STejun Heo * If the first unpopulated page is beyond the end of the 517a16037c8STejun Heo * allocation, the whole allocation is populated; 518a16037c8STejun Heo * otherwise, retry from the end of the unpopulated area. 519a16037c8STejun Heo */ 520a16037c8STejun Heo page_start = PFN_DOWN(head + off); 521a16037c8STejun Heo page_end = PFN_UP(head + off + size); 522a16037c8STejun Heo 523a16037c8STejun Heo rs = page_start; 524a16037c8STejun Heo pcpu_next_unpop(chunk, &rs, &re, PFN_UP(off + this_size)); 525a16037c8STejun Heo if (rs >= page_end) 526a16037c8STejun Heo return head; 527a16037c8STejun Heo cand_off = re * PAGE_SIZE; 528a16037c8STejun Heo } 529a16037c8STejun Heo } 530a16037c8STejun Heo 531a16037c8STejun Heo /** 532fbf59bc9STejun Heo * pcpu_alloc_area - allocate area from a pcpu_chunk 533fbf59bc9STejun Heo * @chunk: chunk of interest 534cae3aeb8STejun Heo * @size: wanted size in bytes 535fbf59bc9STejun Heo * @align: wanted align 536a16037c8STejun Heo * @pop_only: allocate only from the populated area 537b539b87fSTejun Heo * @occ_pages_p: out param for the number of pages the area occupies 538fbf59bc9STejun Heo * 539fbf59bc9STejun Heo * Try to allocate @size bytes area aligned at @align from @chunk. 540fbf59bc9STejun Heo * Note that this function only allocates the offset. It doesn't 541fbf59bc9STejun Heo * populate or map the area. 542fbf59bc9STejun Heo * 5439f7dcf22STejun Heo * @chunk->map must have at least two free slots. 5449f7dcf22STejun Heo * 545ccea34b5STejun Heo * CONTEXT: 546ccea34b5STejun Heo * pcpu_lock. 547ccea34b5STejun Heo * 548fbf59bc9STejun Heo * RETURNS: 5499f7dcf22STejun Heo * Allocated offset in @chunk on success, -1 if no matching area is 5509f7dcf22STejun Heo * found. 551fbf59bc9STejun Heo */ 552a16037c8STejun Heo static int pcpu_alloc_area(struct pcpu_chunk *chunk, int size, int align, 553b539b87fSTejun Heo bool pop_only, int *occ_pages_p) 554fbf59bc9STejun Heo { 555fbf59bc9STejun Heo int oslot = pcpu_chunk_slot(chunk); 556fbf59bc9STejun Heo int max_contig = 0; 557fbf59bc9STejun Heo int i, off; 5583d331ad7SAl Viro bool seen_free = false; 559723ad1d9SAl Viro int *p; 560fbf59bc9STejun Heo 5613d331ad7SAl Viro for (i = chunk->first_free, p = chunk->map + i; i < chunk->map_used; i++, p++) { 562fbf59bc9STejun Heo int head, tail; 563723ad1d9SAl Viro int this_size; 564723ad1d9SAl Viro 565723ad1d9SAl Viro off = *p; 566723ad1d9SAl Viro if (off & 1) 567723ad1d9SAl Viro continue; 568fbf59bc9STejun Heo 569723ad1d9SAl Viro this_size = (p[1] & ~1) - off; 570a16037c8STejun Heo 571a16037c8STejun Heo head = pcpu_fit_in_area(chunk, off, this_size, size, align, 572a16037c8STejun Heo pop_only); 573a16037c8STejun Heo if (head < 0) { 5743d331ad7SAl Viro if (!seen_free) { 5753d331ad7SAl Viro chunk->first_free = i; 5763d331ad7SAl Viro seen_free = true; 5773d331ad7SAl Viro } 578723ad1d9SAl Viro max_contig = max(this_size, max_contig); 579fbf59bc9STejun Heo continue; 580fbf59bc9STejun Heo } 581fbf59bc9STejun Heo 582fbf59bc9STejun Heo /* 583fbf59bc9STejun Heo * If head is small or the previous block is free, 584fbf59bc9STejun Heo * merge'em. Note that 'small' is defined as smaller 585fbf59bc9STejun Heo * than sizeof(int), which is very small but isn't too 586fbf59bc9STejun Heo * uncommon for percpu allocations. 587fbf59bc9STejun Heo */ 588723ad1d9SAl Viro if (head && (head < sizeof(int) || !(p[-1] & 1))) { 58921ddfd38SJianyu Zhan *p = off += head; 590723ad1d9SAl Viro if (p[-1] & 1) 591fbf59bc9STejun Heo chunk->free_size -= head; 59221ddfd38SJianyu Zhan else 59321ddfd38SJianyu Zhan max_contig = max(*p - p[-1], max_contig); 594723ad1d9SAl Viro this_size -= head; 595fbf59bc9STejun Heo head = 0; 596fbf59bc9STejun Heo } 597fbf59bc9STejun Heo 598fbf59bc9STejun Heo /* if tail is small, just keep it around */ 599723ad1d9SAl Viro tail = this_size - head - size; 600723ad1d9SAl Viro if (tail < sizeof(int)) { 601fbf59bc9STejun Heo tail = 0; 602723ad1d9SAl Viro size = this_size - head; 603723ad1d9SAl Viro } 604fbf59bc9STejun Heo 605fbf59bc9STejun Heo /* split if warranted */ 606fbf59bc9STejun Heo if (head || tail) { 607706c16f2SAl Viro int nr_extra = !!head + !!tail; 608706c16f2SAl Viro 609706c16f2SAl Viro /* insert new subblocks */ 610723ad1d9SAl Viro memmove(p + nr_extra + 1, p + 1, 611706c16f2SAl Viro sizeof(chunk->map[0]) * (chunk->map_used - i)); 612706c16f2SAl Viro chunk->map_used += nr_extra; 613706c16f2SAl Viro 614fbf59bc9STejun Heo if (head) { 6153d331ad7SAl Viro if (!seen_free) { 6163d331ad7SAl Viro chunk->first_free = i; 6173d331ad7SAl Viro seen_free = true; 6183d331ad7SAl Viro } 619723ad1d9SAl Viro *++p = off += head; 620723ad1d9SAl Viro ++i; 621706c16f2SAl Viro max_contig = max(head, max_contig); 622fbf59bc9STejun Heo } 623706c16f2SAl Viro if (tail) { 624723ad1d9SAl Viro p[1] = off + size; 625706c16f2SAl Viro max_contig = max(tail, max_contig); 626706c16f2SAl Viro } 627fbf59bc9STejun Heo } 628fbf59bc9STejun Heo 6293d331ad7SAl Viro if (!seen_free) 6303d331ad7SAl Viro chunk->first_free = i + 1; 6313d331ad7SAl Viro 632fbf59bc9STejun Heo /* update hint and mark allocated */ 633723ad1d9SAl Viro if (i + 1 == chunk->map_used) 634fbf59bc9STejun Heo chunk->contig_hint = max_contig; /* fully scanned */ 635fbf59bc9STejun Heo else 636fbf59bc9STejun Heo chunk->contig_hint = max(chunk->contig_hint, 637fbf59bc9STejun Heo max_contig); 638fbf59bc9STejun Heo 639723ad1d9SAl Viro chunk->free_size -= size; 640723ad1d9SAl Viro *p |= 1; 641fbf59bc9STejun Heo 642b539b87fSTejun Heo *occ_pages_p = pcpu_count_occupied_pages(chunk, i); 643fbf59bc9STejun Heo pcpu_chunk_relocate(chunk, oslot); 644fbf59bc9STejun Heo return off; 645fbf59bc9STejun Heo } 646fbf59bc9STejun Heo 647fbf59bc9STejun Heo chunk->contig_hint = max_contig; /* fully scanned */ 648fbf59bc9STejun Heo pcpu_chunk_relocate(chunk, oslot); 649fbf59bc9STejun Heo 6509f7dcf22STejun Heo /* tell the upper layer that this chunk has no matching area */ 6519f7dcf22STejun Heo return -1; 652fbf59bc9STejun Heo } 653fbf59bc9STejun Heo 654fbf59bc9STejun Heo /** 655fbf59bc9STejun Heo * pcpu_free_area - free area to a pcpu_chunk 656fbf59bc9STejun Heo * @chunk: chunk of interest 657fbf59bc9STejun Heo * @freeme: offset of area to free 658b539b87fSTejun Heo * @occ_pages_p: out param for the number of pages the area occupies 659fbf59bc9STejun Heo * 660fbf59bc9STejun Heo * Free area starting from @freeme to @chunk. Note that this function 661fbf59bc9STejun Heo * only modifies the allocation map. It doesn't depopulate or unmap 662fbf59bc9STejun Heo * the area. 663ccea34b5STejun Heo * 664ccea34b5STejun Heo * CONTEXT: 665ccea34b5STejun Heo * pcpu_lock. 666fbf59bc9STejun Heo */ 667b539b87fSTejun Heo static void pcpu_free_area(struct pcpu_chunk *chunk, int freeme, 668b539b87fSTejun Heo int *occ_pages_p) 669fbf59bc9STejun Heo { 670fbf59bc9STejun Heo int oslot = pcpu_chunk_slot(chunk); 671723ad1d9SAl Viro int off = 0; 672723ad1d9SAl Viro unsigned i, j; 673723ad1d9SAl Viro int to_free = 0; 674723ad1d9SAl Viro int *p; 675fbf59bc9STejun Heo 6765ccd30e4SDennis Zhou lockdep_assert_held(&pcpu_lock); 67730a5b536SDennis Zhou pcpu_stats_area_dealloc(chunk); 6785ccd30e4SDennis Zhou 679723ad1d9SAl Viro freeme |= 1; /* we are searching for <given offset, in use> pair */ 680723ad1d9SAl Viro 681723ad1d9SAl Viro i = 0; 682723ad1d9SAl Viro j = chunk->map_used; 683723ad1d9SAl Viro while (i != j) { 684723ad1d9SAl Viro unsigned k = (i + j) / 2; 685723ad1d9SAl Viro off = chunk->map[k]; 686723ad1d9SAl Viro if (off < freeme) 687723ad1d9SAl Viro i = k + 1; 688723ad1d9SAl Viro else if (off > freeme) 689723ad1d9SAl Viro j = k; 690723ad1d9SAl Viro else 691723ad1d9SAl Viro i = j = k; 692723ad1d9SAl Viro } 693fbf59bc9STejun Heo BUG_ON(off != freeme); 694fbf59bc9STejun Heo 6953d331ad7SAl Viro if (i < chunk->first_free) 6963d331ad7SAl Viro chunk->first_free = i; 6973d331ad7SAl Viro 698723ad1d9SAl Viro p = chunk->map + i; 699723ad1d9SAl Viro *p = off &= ~1; 700723ad1d9SAl Viro chunk->free_size += (p[1] & ~1) - off; 701fbf59bc9STejun Heo 702b539b87fSTejun Heo *occ_pages_p = pcpu_count_occupied_pages(chunk, i); 703b539b87fSTejun Heo 704fbf59bc9STejun Heo /* merge with next? */ 705723ad1d9SAl Viro if (!(p[1] & 1)) 706723ad1d9SAl Viro to_free++; 707723ad1d9SAl Viro /* merge with previous? */ 708723ad1d9SAl Viro if (i > 0 && !(p[-1] & 1)) { 709723ad1d9SAl Viro to_free++; 710723ad1d9SAl Viro i--; 711723ad1d9SAl Viro p--; 712723ad1d9SAl Viro } 713723ad1d9SAl Viro if (to_free) { 714723ad1d9SAl Viro chunk->map_used -= to_free; 715723ad1d9SAl Viro memmove(p + 1, p + 1 + to_free, 716723ad1d9SAl Viro (chunk->map_used - i) * sizeof(chunk->map[0])); 717fbf59bc9STejun Heo } 718fbf59bc9STejun Heo 719723ad1d9SAl Viro chunk->contig_hint = max(chunk->map[i + 1] - chunk->map[i] - 1, chunk->contig_hint); 720fbf59bc9STejun Heo pcpu_chunk_relocate(chunk, oslot); 721fbf59bc9STejun Heo } 722fbf59bc9STejun Heo 723c0ebfdc3SDennis Zhou (Facebook) static struct pcpu_chunk * __init pcpu_alloc_first_chunk(unsigned long tmp_addr, 72410edf5b0SDennis Zhou (Facebook) int map_size, 72510edf5b0SDennis Zhou (Facebook) int *map, 72610edf5b0SDennis Zhou (Facebook) int init_map_size) 72710edf5b0SDennis Zhou (Facebook) { 72810edf5b0SDennis Zhou (Facebook) struct pcpu_chunk *chunk; 729c0ebfdc3SDennis Zhou (Facebook) unsigned long aligned_addr; 730c0ebfdc3SDennis Zhou (Facebook) int start_offset, region_size; 731c0ebfdc3SDennis Zhou (Facebook) 732c0ebfdc3SDennis Zhou (Facebook) /* region calculations */ 733c0ebfdc3SDennis Zhou (Facebook) aligned_addr = tmp_addr & PAGE_MASK; 734c0ebfdc3SDennis Zhou (Facebook) 735c0ebfdc3SDennis Zhou (Facebook) start_offset = tmp_addr - aligned_addr; 7366b9d7c8eSDennis Zhou (Facebook) 7376b9d7c8eSDennis Zhou (Facebook) region_size = PFN_ALIGN(start_offset + map_size); 73810edf5b0SDennis Zhou (Facebook) 739c0ebfdc3SDennis Zhou (Facebook) /* allocate chunk */ 740*8ab16c43SDennis Zhou (Facebook) chunk = memblock_virt_alloc(sizeof(struct pcpu_chunk) + 741*8ab16c43SDennis Zhou (Facebook) BITS_TO_LONGS(region_size >> PAGE_SHIFT), 742*8ab16c43SDennis Zhou (Facebook) 0); 743c0ebfdc3SDennis Zhou (Facebook) 74410edf5b0SDennis Zhou (Facebook) INIT_LIST_HEAD(&chunk->list); 74510edf5b0SDennis Zhou (Facebook) INIT_LIST_HEAD(&chunk->map_extend_list); 746c0ebfdc3SDennis Zhou (Facebook) 747c0ebfdc3SDennis Zhou (Facebook) chunk->base_addr = (void *)aligned_addr; 74810edf5b0SDennis Zhou (Facebook) chunk->start_offset = start_offset; 7496b9d7c8eSDennis Zhou (Facebook) chunk->end_offset = region_size - chunk->start_offset - map_size; 750c0ebfdc3SDennis Zhou (Facebook) 751*8ab16c43SDennis Zhou (Facebook) chunk->nr_pages = region_size >> PAGE_SHIFT; 752c0ebfdc3SDennis Zhou (Facebook) 75310edf5b0SDennis Zhou (Facebook) chunk->map = map; 75410edf5b0SDennis Zhou (Facebook) chunk->map_alloc = init_map_size; 75510edf5b0SDennis Zhou (Facebook) 75610edf5b0SDennis Zhou (Facebook) /* manage populated page bitmap */ 75710edf5b0SDennis Zhou (Facebook) chunk->immutable = true; 758*8ab16c43SDennis Zhou (Facebook) bitmap_fill(chunk->populated, chunk->nr_pages); 759*8ab16c43SDennis Zhou (Facebook) chunk->nr_populated = chunk->nr_pages; 76010edf5b0SDennis Zhou (Facebook) 76110edf5b0SDennis Zhou (Facebook) chunk->contig_hint = chunk->free_size = map_size; 762c0ebfdc3SDennis Zhou (Facebook) 763c0ebfdc3SDennis Zhou (Facebook) if (chunk->start_offset) { 764c0ebfdc3SDennis Zhou (Facebook) /* hide the beginning of the bitmap */ 76510edf5b0SDennis Zhou (Facebook) chunk->map[0] = 1; 76610edf5b0SDennis Zhou (Facebook) chunk->map[1] = chunk->start_offset; 767c0ebfdc3SDennis Zhou (Facebook) chunk->map_used = 1; 768c0ebfdc3SDennis Zhou (Facebook) } 769c0ebfdc3SDennis Zhou (Facebook) 770c0ebfdc3SDennis Zhou (Facebook) /* set chunk's free region */ 771c0ebfdc3SDennis Zhou (Facebook) chunk->map[++chunk->map_used] = 772c0ebfdc3SDennis Zhou (Facebook) (chunk->start_offset + chunk->free_size) | 1; 77310edf5b0SDennis Zhou (Facebook) 7746b9d7c8eSDennis Zhou (Facebook) if (chunk->end_offset) { 7756b9d7c8eSDennis Zhou (Facebook) /* hide the end of the bitmap */ 7766b9d7c8eSDennis Zhou (Facebook) chunk->map[++chunk->map_used] = region_size | 1; 7776b9d7c8eSDennis Zhou (Facebook) } 7786b9d7c8eSDennis Zhou (Facebook) 77910edf5b0SDennis Zhou (Facebook) return chunk; 78010edf5b0SDennis Zhou (Facebook) } 78110edf5b0SDennis Zhou (Facebook) 7826081089fSTejun Heo static struct pcpu_chunk *pcpu_alloc_chunk(void) 7836081089fSTejun Heo { 7846081089fSTejun Heo struct pcpu_chunk *chunk; 7856081089fSTejun Heo 78690459ce0SBob Liu chunk = pcpu_mem_zalloc(pcpu_chunk_struct_size); 7876081089fSTejun Heo if (!chunk) 7886081089fSTejun Heo return NULL; 7896081089fSTejun Heo 79090459ce0SBob Liu chunk->map = pcpu_mem_zalloc(PCPU_DFL_MAP_ALLOC * 79190459ce0SBob Liu sizeof(chunk->map[0])); 7926081089fSTejun Heo if (!chunk->map) { 7931d5cfdb0STetsuo Handa pcpu_mem_free(chunk); 7946081089fSTejun Heo return NULL; 7956081089fSTejun Heo } 7966081089fSTejun Heo 7976081089fSTejun Heo chunk->map_alloc = PCPU_DFL_MAP_ALLOC; 798723ad1d9SAl Viro chunk->map[0] = 0; 799723ad1d9SAl Viro chunk->map[1] = pcpu_unit_size | 1; 800723ad1d9SAl Viro chunk->map_used = 1; 8016081089fSTejun Heo 8026081089fSTejun Heo INIT_LIST_HEAD(&chunk->list); 8034f996e23STejun Heo INIT_LIST_HEAD(&chunk->map_extend_list); 8046081089fSTejun Heo chunk->free_size = pcpu_unit_size; 8056081089fSTejun Heo chunk->contig_hint = pcpu_unit_size; 8066081089fSTejun Heo 807c0ebfdc3SDennis Zhou (Facebook) chunk->nr_pages = pcpu_unit_pages; 808c0ebfdc3SDennis Zhou (Facebook) 8096081089fSTejun Heo return chunk; 8106081089fSTejun Heo } 8116081089fSTejun Heo 8126081089fSTejun Heo static void pcpu_free_chunk(struct pcpu_chunk *chunk) 8136081089fSTejun Heo { 8146081089fSTejun Heo if (!chunk) 8156081089fSTejun Heo return; 8161d5cfdb0STetsuo Handa pcpu_mem_free(chunk->map); 8171d5cfdb0STetsuo Handa pcpu_mem_free(chunk); 8186081089fSTejun Heo } 8196081089fSTejun Heo 820b539b87fSTejun Heo /** 821b539b87fSTejun Heo * pcpu_chunk_populated - post-population bookkeeping 822b539b87fSTejun Heo * @chunk: pcpu_chunk which got populated 823b539b87fSTejun Heo * @page_start: the start page 824b539b87fSTejun Heo * @page_end: the end page 825b539b87fSTejun Heo * 826b539b87fSTejun Heo * Pages in [@page_start,@page_end) have been populated to @chunk. Update 827b539b87fSTejun Heo * the bookkeeping information accordingly. Must be called after each 828b539b87fSTejun Heo * successful population. 829b539b87fSTejun Heo */ 830b539b87fSTejun Heo static void pcpu_chunk_populated(struct pcpu_chunk *chunk, 831b539b87fSTejun Heo int page_start, int page_end) 832b539b87fSTejun Heo { 833b539b87fSTejun Heo int nr = page_end - page_start; 834b539b87fSTejun Heo 835b539b87fSTejun Heo lockdep_assert_held(&pcpu_lock); 836b539b87fSTejun Heo 837b539b87fSTejun Heo bitmap_set(chunk->populated, page_start, nr); 838b539b87fSTejun Heo chunk->nr_populated += nr; 839b539b87fSTejun Heo pcpu_nr_empty_pop_pages += nr; 840b539b87fSTejun Heo } 841b539b87fSTejun Heo 842b539b87fSTejun Heo /** 843b539b87fSTejun Heo * pcpu_chunk_depopulated - post-depopulation bookkeeping 844b539b87fSTejun Heo * @chunk: pcpu_chunk which got depopulated 845b539b87fSTejun Heo * @page_start: the start page 846b539b87fSTejun Heo * @page_end: the end page 847b539b87fSTejun Heo * 848b539b87fSTejun Heo * Pages in [@page_start,@page_end) have been depopulated from @chunk. 849b539b87fSTejun Heo * Update the bookkeeping information accordingly. Must be called after 850b539b87fSTejun Heo * each successful depopulation. 851b539b87fSTejun Heo */ 852b539b87fSTejun Heo static void pcpu_chunk_depopulated(struct pcpu_chunk *chunk, 853b539b87fSTejun Heo int page_start, int page_end) 854b539b87fSTejun Heo { 855b539b87fSTejun Heo int nr = page_end - page_start; 856b539b87fSTejun Heo 857b539b87fSTejun Heo lockdep_assert_held(&pcpu_lock); 858b539b87fSTejun Heo 859b539b87fSTejun Heo bitmap_clear(chunk->populated, page_start, nr); 860b539b87fSTejun Heo chunk->nr_populated -= nr; 861b539b87fSTejun Heo pcpu_nr_empty_pop_pages -= nr; 862b539b87fSTejun Heo } 863b539b87fSTejun Heo 864fbf59bc9STejun Heo /* 8659f645532STejun Heo * Chunk management implementation. 866fbf59bc9STejun Heo * 8679f645532STejun Heo * To allow different implementations, chunk alloc/free and 8689f645532STejun Heo * [de]population are implemented in a separate file which is pulled 8699f645532STejun Heo * into this file and compiled together. The following functions 8709f645532STejun Heo * should be implemented. 871ccea34b5STejun Heo * 8729f645532STejun Heo * pcpu_populate_chunk - populate the specified range of a chunk 8739f645532STejun Heo * pcpu_depopulate_chunk - depopulate the specified range of a chunk 8749f645532STejun Heo * pcpu_create_chunk - create a new chunk 8759f645532STejun Heo * pcpu_destroy_chunk - destroy a chunk, always preceded by full depop 8769f645532STejun Heo * pcpu_addr_to_page - translate address to physical address 8779f645532STejun Heo * pcpu_verify_alloc_info - check alloc_info is acceptable during init 878fbf59bc9STejun Heo */ 8799f645532STejun Heo static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size); 8809f645532STejun Heo static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size); 8819f645532STejun Heo static struct pcpu_chunk *pcpu_create_chunk(void); 8829f645532STejun Heo static void pcpu_destroy_chunk(struct pcpu_chunk *chunk); 8839f645532STejun Heo static struct page *pcpu_addr_to_page(void *addr); 8849f645532STejun Heo static int __init pcpu_verify_alloc_info(const struct pcpu_alloc_info *ai); 885fbf59bc9STejun Heo 886b0c9778bSTejun Heo #ifdef CONFIG_NEED_PER_CPU_KM 887b0c9778bSTejun Heo #include "percpu-km.c" 888b0c9778bSTejun Heo #else 8899f645532STejun Heo #include "percpu-vm.c" 890b0c9778bSTejun Heo #endif 891fbf59bc9STejun Heo 892fbf59bc9STejun Heo /** 89388999a89STejun Heo * pcpu_chunk_addr_search - determine chunk containing specified address 89488999a89STejun Heo * @addr: address for which the chunk needs to be determined. 89588999a89STejun Heo * 896c0ebfdc3SDennis Zhou (Facebook) * This is an internal function that handles all but static allocations. 897c0ebfdc3SDennis Zhou (Facebook) * Static percpu address values should never be passed into the allocator. 898c0ebfdc3SDennis Zhou (Facebook) * 89988999a89STejun Heo * RETURNS: 90088999a89STejun Heo * The address of the found chunk. 90188999a89STejun Heo */ 90288999a89STejun Heo static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr) 90388999a89STejun Heo { 904c0ebfdc3SDennis Zhou (Facebook) /* is it in the dynamic region (first chunk)? */ 905560f2c23SDennis Zhou (Facebook) if (pcpu_addr_in_chunk(pcpu_first_chunk, addr)) 906c0ebfdc3SDennis Zhou (Facebook) return pcpu_first_chunk; 907c0ebfdc3SDennis Zhou (Facebook) 908c0ebfdc3SDennis Zhou (Facebook) /* is it in the reserved region? */ 909560f2c23SDennis Zhou (Facebook) if (pcpu_addr_in_chunk(pcpu_reserved_chunk, addr)) 91088999a89STejun Heo return pcpu_reserved_chunk; 91188999a89STejun Heo 91288999a89STejun Heo /* 91388999a89STejun Heo * The address is relative to unit0 which might be unused and 91488999a89STejun Heo * thus unmapped. Offset the address to the unit space of the 91588999a89STejun Heo * current processor before looking it up in the vmalloc 91688999a89STejun Heo * space. Note that any possible cpu id can be used here, so 91788999a89STejun Heo * there's no need to worry about preemption or cpu hotplug. 91888999a89STejun Heo */ 91988999a89STejun Heo addr += pcpu_unit_offsets[raw_smp_processor_id()]; 9209f645532STejun Heo return pcpu_get_page_chunk(pcpu_addr_to_page(addr)); 92188999a89STejun Heo } 92288999a89STejun Heo 92388999a89STejun Heo /** 924edcb4639STejun Heo * pcpu_alloc - the percpu allocator 925cae3aeb8STejun Heo * @size: size of area to allocate in bytes 926fbf59bc9STejun Heo * @align: alignment of area (max PAGE_SIZE) 927edcb4639STejun Heo * @reserved: allocate from the reserved chunk if available 9285835d96eSTejun Heo * @gfp: allocation flags 929fbf59bc9STejun Heo * 9305835d96eSTejun Heo * Allocate percpu area of @size bytes aligned at @align. If @gfp doesn't 9315835d96eSTejun Heo * contain %GFP_KERNEL, the allocation is atomic. 932fbf59bc9STejun Heo * 933fbf59bc9STejun Heo * RETURNS: 934fbf59bc9STejun Heo * Percpu pointer to the allocated area on success, NULL on failure. 935fbf59bc9STejun Heo */ 9365835d96eSTejun Heo static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved, 9375835d96eSTejun Heo gfp_t gfp) 938fbf59bc9STejun Heo { 939f2badb0cSTejun Heo static int warn_limit = 10; 940fbf59bc9STejun Heo struct pcpu_chunk *chunk; 941f2badb0cSTejun Heo const char *err; 9426ae833c7STejun Heo bool is_atomic = (gfp & GFP_KERNEL) != GFP_KERNEL; 943b539b87fSTejun Heo int occ_pages = 0; 944b38d08f3STejun Heo int slot, off, new_alloc, cpu, ret; 945403a91b1SJiri Kosina unsigned long flags; 946f528f0b8SCatalin Marinas void __percpu *ptr; 947fbf59bc9STejun Heo 948723ad1d9SAl Viro /* 949723ad1d9SAl Viro * We want the lowest bit of offset available for in-use/free 9502f69fa82SViro * indicator, so force >= 16bit alignment and make size even. 951723ad1d9SAl Viro */ 952723ad1d9SAl Viro if (unlikely(align < 2)) 953723ad1d9SAl Viro align = 2; 954723ad1d9SAl Viro 955fb009e3aSChristoph Lameter size = ALIGN(size, 2); 9562f69fa82SViro 9573ca45a46Szijun_hu if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE || 9583ca45a46Szijun_hu !is_power_of_2(align))) { 959756a025fSJoe Perches WARN(true, "illegal size (%zu) or align (%zu) for percpu allocation\n", 960756a025fSJoe Perches size, align); 961fbf59bc9STejun Heo return NULL; 962fbf59bc9STejun Heo } 963fbf59bc9STejun Heo 9646710e594STejun Heo if (!is_atomic) 9656710e594STejun Heo mutex_lock(&pcpu_alloc_mutex); 9666710e594STejun Heo 967403a91b1SJiri Kosina spin_lock_irqsave(&pcpu_lock, flags); 968fbf59bc9STejun Heo 969edcb4639STejun Heo /* serve reserved allocations from the reserved chunk if available */ 970edcb4639STejun Heo if (reserved && pcpu_reserved_chunk) { 971edcb4639STejun Heo chunk = pcpu_reserved_chunk; 972833af842STejun Heo 973833af842STejun Heo if (size > chunk->contig_hint) { 974833af842STejun Heo err = "alloc from reserved chunk failed"; 975ccea34b5STejun Heo goto fail_unlock; 976f2badb0cSTejun Heo } 977833af842STejun Heo 9789c824b6aSTejun Heo while ((new_alloc = pcpu_need_to_extend(chunk, is_atomic))) { 979833af842STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 9805835d96eSTejun Heo if (is_atomic || 9815835d96eSTejun Heo pcpu_extend_area_map(chunk, new_alloc) < 0) { 982833af842STejun Heo err = "failed to extend area map of reserved chunk"; 983b38d08f3STejun Heo goto fail; 984833af842STejun Heo } 985833af842STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 986833af842STejun Heo } 987833af842STejun Heo 988b539b87fSTejun Heo off = pcpu_alloc_area(chunk, size, align, is_atomic, 989b539b87fSTejun Heo &occ_pages); 990edcb4639STejun Heo if (off >= 0) 991edcb4639STejun Heo goto area_found; 992833af842STejun Heo 993f2badb0cSTejun Heo err = "alloc from reserved chunk failed"; 994ccea34b5STejun Heo goto fail_unlock; 995edcb4639STejun Heo } 996edcb4639STejun Heo 997ccea34b5STejun Heo restart: 998edcb4639STejun Heo /* search through normal chunks */ 999fbf59bc9STejun Heo for (slot = pcpu_size_to_slot(size); slot < pcpu_nr_slots; slot++) { 1000fbf59bc9STejun Heo list_for_each_entry(chunk, &pcpu_slot[slot], list) { 1001fbf59bc9STejun Heo if (size > chunk->contig_hint) 1002fbf59bc9STejun Heo continue; 1003ccea34b5STejun Heo 10049c824b6aSTejun Heo new_alloc = pcpu_need_to_extend(chunk, is_atomic); 1005833af842STejun Heo if (new_alloc) { 10065835d96eSTejun Heo if (is_atomic) 10075835d96eSTejun Heo continue; 1008833af842STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 1009833af842STejun Heo if (pcpu_extend_area_map(chunk, 1010833af842STejun Heo new_alloc) < 0) { 1011f2badb0cSTejun Heo err = "failed to extend area map"; 1012b38d08f3STejun Heo goto fail; 1013833af842STejun Heo } 1014833af842STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 1015833af842STejun Heo /* 1016833af842STejun Heo * pcpu_lock has been dropped, need to 1017833af842STejun Heo * restart cpu_slot list walking. 1018833af842STejun Heo */ 1019833af842STejun Heo goto restart; 1020ccea34b5STejun Heo } 1021ccea34b5STejun Heo 1022b539b87fSTejun Heo off = pcpu_alloc_area(chunk, size, align, is_atomic, 1023b539b87fSTejun Heo &occ_pages); 1024fbf59bc9STejun Heo if (off >= 0) 1025fbf59bc9STejun Heo goto area_found; 1026fbf59bc9STejun Heo } 1027fbf59bc9STejun Heo } 1028fbf59bc9STejun Heo 1029403a91b1SJiri Kosina spin_unlock_irqrestore(&pcpu_lock, flags); 1030ccea34b5STejun Heo 1031b38d08f3STejun Heo /* 1032b38d08f3STejun Heo * No space left. Create a new chunk. We don't want multiple 1033b38d08f3STejun Heo * tasks to create chunks simultaneously. Serialize and create iff 1034b38d08f3STejun Heo * there's still no empty chunk after grabbing the mutex. 1035b38d08f3STejun Heo */ 103611df02bfSDennis Zhou if (is_atomic) { 103711df02bfSDennis Zhou err = "atomic alloc failed, no space left"; 10385835d96eSTejun Heo goto fail; 103911df02bfSDennis Zhou } 10405835d96eSTejun Heo 1041b38d08f3STejun Heo if (list_empty(&pcpu_slot[pcpu_nr_slots - 1])) { 10426081089fSTejun Heo chunk = pcpu_create_chunk(); 1043f2badb0cSTejun Heo if (!chunk) { 1044f2badb0cSTejun Heo err = "failed to allocate new chunk"; 1045b38d08f3STejun Heo goto fail; 1046f2badb0cSTejun Heo } 1047ccea34b5STejun Heo 1048403a91b1SJiri Kosina spin_lock_irqsave(&pcpu_lock, flags); 1049fbf59bc9STejun Heo pcpu_chunk_relocate(chunk, -1); 1050b38d08f3STejun Heo } else { 1051b38d08f3STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 1052b38d08f3STejun Heo } 1053b38d08f3STejun Heo 1054ccea34b5STejun Heo goto restart; 1055fbf59bc9STejun Heo 1056fbf59bc9STejun Heo area_found: 105730a5b536SDennis Zhou pcpu_stats_area_alloc(chunk, size); 1058403a91b1SJiri Kosina spin_unlock_irqrestore(&pcpu_lock, flags); 1059ccea34b5STejun Heo 1060dca49645STejun Heo /* populate if not all pages are already there */ 10615835d96eSTejun Heo if (!is_atomic) { 1062e04d3208STejun Heo int page_start, page_end, rs, re; 1063e04d3208STejun Heo 1064dca49645STejun Heo page_start = PFN_DOWN(off); 1065dca49645STejun Heo page_end = PFN_UP(off + size); 1066dca49645STejun Heo 1067a93ace48STejun Heo pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) { 1068dca49645STejun Heo WARN_ON(chunk->immutable); 1069dca49645STejun Heo 1070b38d08f3STejun Heo ret = pcpu_populate_chunk(chunk, rs, re); 1071b38d08f3STejun Heo 1072403a91b1SJiri Kosina spin_lock_irqsave(&pcpu_lock, flags); 1073b38d08f3STejun Heo if (ret) { 1074b539b87fSTejun Heo pcpu_free_area(chunk, off, &occ_pages); 1075f2badb0cSTejun Heo err = "failed to populate"; 1076ccea34b5STejun Heo goto fail_unlock; 1077fbf59bc9STejun Heo } 1078b539b87fSTejun Heo pcpu_chunk_populated(chunk, rs, re); 1079b38d08f3STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 1080dca49645STejun Heo } 1081dca49645STejun Heo 1082ccea34b5STejun Heo mutex_unlock(&pcpu_alloc_mutex); 1083e04d3208STejun Heo } 1084ccea34b5STejun Heo 1085320661b0STahsin Erdogan if (chunk != pcpu_reserved_chunk) { 1086320661b0STahsin Erdogan spin_lock_irqsave(&pcpu_lock, flags); 1087b539b87fSTejun Heo pcpu_nr_empty_pop_pages -= occ_pages; 1088320661b0STahsin Erdogan spin_unlock_irqrestore(&pcpu_lock, flags); 1089320661b0STahsin Erdogan } 1090b539b87fSTejun Heo 10911a4d7607STejun Heo if (pcpu_nr_empty_pop_pages < PCPU_EMPTY_POP_PAGES_LOW) 10921a4d7607STejun Heo pcpu_schedule_balance_work(); 10931a4d7607STejun Heo 1094dca49645STejun Heo /* clear the areas and return address relative to base address */ 1095dca49645STejun Heo for_each_possible_cpu(cpu) 1096dca49645STejun Heo memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size); 1097dca49645STejun Heo 1098f528f0b8SCatalin Marinas ptr = __addr_to_pcpu_ptr(chunk->base_addr + off); 10998a8c35faSLarry Finger kmemleak_alloc_percpu(ptr, size, gfp); 1100df95e795SDennis Zhou 1101df95e795SDennis Zhou trace_percpu_alloc_percpu(reserved, is_atomic, size, align, 1102df95e795SDennis Zhou chunk->base_addr, off, ptr); 1103df95e795SDennis Zhou 1104f528f0b8SCatalin Marinas return ptr; 1105ccea34b5STejun Heo 1106ccea34b5STejun Heo fail_unlock: 1107403a91b1SJiri Kosina spin_unlock_irqrestore(&pcpu_lock, flags); 1108b38d08f3STejun Heo fail: 1109df95e795SDennis Zhou trace_percpu_alloc_percpu_fail(reserved, is_atomic, size, align); 1110df95e795SDennis Zhou 11115835d96eSTejun Heo if (!is_atomic && warn_limit) { 1112870d4b12SJoe Perches pr_warn("allocation failed, size=%zu align=%zu atomic=%d, %s\n", 11135835d96eSTejun Heo size, align, is_atomic, err); 1114f2badb0cSTejun Heo dump_stack(); 1115f2badb0cSTejun Heo if (!--warn_limit) 1116870d4b12SJoe Perches pr_info("limit reached, disable warning\n"); 1117f2badb0cSTejun Heo } 11181a4d7607STejun Heo if (is_atomic) { 11191a4d7607STejun Heo /* see the flag handling in pcpu_blance_workfn() */ 11201a4d7607STejun Heo pcpu_atomic_alloc_failed = true; 11211a4d7607STejun Heo pcpu_schedule_balance_work(); 11226710e594STejun Heo } else { 11236710e594STejun Heo mutex_unlock(&pcpu_alloc_mutex); 11241a4d7607STejun Heo } 1125ccea34b5STejun Heo return NULL; 1126fbf59bc9STejun Heo } 1127edcb4639STejun Heo 1128edcb4639STejun Heo /** 11295835d96eSTejun Heo * __alloc_percpu_gfp - allocate dynamic percpu area 1130edcb4639STejun Heo * @size: size of area to allocate in bytes 1131edcb4639STejun Heo * @align: alignment of area (max PAGE_SIZE) 11325835d96eSTejun Heo * @gfp: allocation flags 1133edcb4639STejun Heo * 11345835d96eSTejun Heo * Allocate zero-filled percpu area of @size bytes aligned at @align. If 11355835d96eSTejun Heo * @gfp doesn't contain %GFP_KERNEL, the allocation doesn't block and can 11365835d96eSTejun Heo * be called from any context but is a lot more likely to fail. 1137ccea34b5STejun Heo * 1138edcb4639STejun Heo * RETURNS: 1139edcb4639STejun Heo * Percpu pointer to the allocated area on success, NULL on failure. 1140edcb4639STejun Heo */ 11415835d96eSTejun Heo void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp) 11425835d96eSTejun Heo { 11435835d96eSTejun Heo return pcpu_alloc(size, align, false, gfp); 11445835d96eSTejun Heo } 11455835d96eSTejun Heo EXPORT_SYMBOL_GPL(__alloc_percpu_gfp); 11465835d96eSTejun Heo 11475835d96eSTejun Heo /** 11485835d96eSTejun Heo * __alloc_percpu - allocate dynamic percpu area 11495835d96eSTejun Heo * @size: size of area to allocate in bytes 11505835d96eSTejun Heo * @align: alignment of area (max PAGE_SIZE) 11515835d96eSTejun Heo * 11525835d96eSTejun Heo * Equivalent to __alloc_percpu_gfp(size, align, %GFP_KERNEL). 11535835d96eSTejun Heo */ 115443cf38ebSTejun Heo void __percpu *__alloc_percpu(size_t size, size_t align) 1155edcb4639STejun Heo { 11565835d96eSTejun Heo return pcpu_alloc(size, align, false, GFP_KERNEL); 1157edcb4639STejun Heo } 1158fbf59bc9STejun Heo EXPORT_SYMBOL_GPL(__alloc_percpu); 1159fbf59bc9STejun Heo 1160edcb4639STejun Heo /** 1161edcb4639STejun Heo * __alloc_reserved_percpu - allocate reserved percpu area 1162edcb4639STejun Heo * @size: size of area to allocate in bytes 1163edcb4639STejun Heo * @align: alignment of area (max PAGE_SIZE) 1164edcb4639STejun Heo * 11659329ba97STejun Heo * Allocate zero-filled percpu area of @size bytes aligned at @align 11669329ba97STejun Heo * from reserved percpu area if arch has set it up; otherwise, 11679329ba97STejun Heo * allocation is served from the same dynamic area. Might sleep. 11689329ba97STejun Heo * Might trigger writeouts. 1169edcb4639STejun Heo * 1170ccea34b5STejun Heo * CONTEXT: 1171ccea34b5STejun Heo * Does GFP_KERNEL allocation. 1172ccea34b5STejun Heo * 1173edcb4639STejun Heo * RETURNS: 1174edcb4639STejun Heo * Percpu pointer to the allocated area on success, NULL on failure. 1175edcb4639STejun Heo */ 117643cf38ebSTejun Heo void __percpu *__alloc_reserved_percpu(size_t size, size_t align) 1177edcb4639STejun Heo { 11785835d96eSTejun Heo return pcpu_alloc(size, align, true, GFP_KERNEL); 1179edcb4639STejun Heo } 1180edcb4639STejun Heo 1181a56dbddfSTejun Heo /** 11821a4d7607STejun Heo * pcpu_balance_workfn - manage the amount of free chunks and populated pages 1183a56dbddfSTejun Heo * @work: unused 1184a56dbddfSTejun Heo * 1185a56dbddfSTejun Heo * Reclaim all fully free chunks except for the first one. 1186a56dbddfSTejun Heo */ 1187fe6bd8c3STejun Heo static void pcpu_balance_workfn(struct work_struct *work) 1188fbf59bc9STejun Heo { 1189fe6bd8c3STejun Heo LIST_HEAD(to_free); 1190fe6bd8c3STejun Heo struct list_head *free_head = &pcpu_slot[pcpu_nr_slots - 1]; 1191a56dbddfSTejun Heo struct pcpu_chunk *chunk, *next; 11921a4d7607STejun Heo int slot, nr_to_pop, ret; 1193a56dbddfSTejun Heo 11941a4d7607STejun Heo /* 11951a4d7607STejun Heo * There's no reason to keep around multiple unused chunks and VM 11961a4d7607STejun Heo * areas can be scarce. Destroy all free chunks except for one. 11971a4d7607STejun Heo */ 1198ccea34b5STejun Heo mutex_lock(&pcpu_alloc_mutex); 1199ccea34b5STejun Heo spin_lock_irq(&pcpu_lock); 1200a56dbddfSTejun Heo 1201fe6bd8c3STejun Heo list_for_each_entry_safe(chunk, next, free_head, list) { 12028d408b4bSTejun Heo WARN_ON(chunk->immutable); 1203a56dbddfSTejun Heo 1204a56dbddfSTejun Heo /* spare the first one */ 1205fe6bd8c3STejun Heo if (chunk == list_first_entry(free_head, struct pcpu_chunk, list)) 1206a56dbddfSTejun Heo continue; 1207a56dbddfSTejun Heo 12084f996e23STejun Heo list_del_init(&chunk->map_extend_list); 1209fe6bd8c3STejun Heo list_move(&chunk->list, &to_free); 1210a56dbddfSTejun Heo } 1211a56dbddfSTejun Heo 1212ccea34b5STejun Heo spin_unlock_irq(&pcpu_lock); 1213a56dbddfSTejun Heo 1214fe6bd8c3STejun Heo list_for_each_entry_safe(chunk, next, &to_free, list) { 1215a93ace48STejun Heo int rs, re; 1216dca49645STejun Heo 1217*8ab16c43SDennis Zhou (Facebook) pcpu_for_each_pop_region(chunk, rs, re, 0, chunk->nr_pages) { 1218a93ace48STejun Heo pcpu_depopulate_chunk(chunk, rs, re); 1219b539b87fSTejun Heo spin_lock_irq(&pcpu_lock); 1220b539b87fSTejun Heo pcpu_chunk_depopulated(chunk, rs, re); 1221b539b87fSTejun Heo spin_unlock_irq(&pcpu_lock); 1222a93ace48STejun Heo } 12236081089fSTejun Heo pcpu_destroy_chunk(chunk); 1224fbf59bc9STejun Heo } 1225971f3918STejun Heo 12264f996e23STejun Heo /* service chunks which requested async area map extension */ 12274f996e23STejun Heo do { 12284f996e23STejun Heo int new_alloc = 0; 12294f996e23STejun Heo 12304f996e23STejun Heo spin_lock_irq(&pcpu_lock); 12314f996e23STejun Heo 12324f996e23STejun Heo chunk = list_first_entry_or_null(&pcpu_map_extend_chunks, 12334f996e23STejun Heo struct pcpu_chunk, map_extend_list); 12344f996e23STejun Heo if (chunk) { 12354f996e23STejun Heo list_del_init(&chunk->map_extend_list); 12364f996e23STejun Heo new_alloc = pcpu_need_to_extend(chunk, false); 12374f996e23STejun Heo } 12384f996e23STejun Heo 12394f996e23STejun Heo spin_unlock_irq(&pcpu_lock); 12404f996e23STejun Heo 12414f996e23STejun Heo if (new_alloc) 12424f996e23STejun Heo pcpu_extend_area_map(chunk, new_alloc); 12434f996e23STejun Heo } while (chunk); 12444f996e23STejun Heo 12451a4d7607STejun Heo /* 12461a4d7607STejun Heo * Ensure there are certain number of free populated pages for 12471a4d7607STejun Heo * atomic allocs. Fill up from the most packed so that atomic 12481a4d7607STejun Heo * allocs don't increase fragmentation. If atomic allocation 12491a4d7607STejun Heo * failed previously, always populate the maximum amount. This 12501a4d7607STejun Heo * should prevent atomic allocs larger than PAGE_SIZE from keeping 12511a4d7607STejun Heo * failing indefinitely; however, large atomic allocs are not 12521a4d7607STejun Heo * something we support properly and can be highly unreliable and 12531a4d7607STejun Heo * inefficient. 12541a4d7607STejun Heo */ 12551a4d7607STejun Heo retry_pop: 12561a4d7607STejun Heo if (pcpu_atomic_alloc_failed) { 12571a4d7607STejun Heo nr_to_pop = PCPU_EMPTY_POP_PAGES_HIGH; 12581a4d7607STejun Heo /* best effort anyway, don't worry about synchronization */ 12591a4d7607STejun Heo pcpu_atomic_alloc_failed = false; 12601a4d7607STejun Heo } else { 12611a4d7607STejun Heo nr_to_pop = clamp(PCPU_EMPTY_POP_PAGES_HIGH - 12621a4d7607STejun Heo pcpu_nr_empty_pop_pages, 12631a4d7607STejun Heo 0, PCPU_EMPTY_POP_PAGES_HIGH); 12641a4d7607STejun Heo } 12651a4d7607STejun Heo 12661a4d7607STejun Heo for (slot = pcpu_size_to_slot(PAGE_SIZE); slot < pcpu_nr_slots; slot++) { 12671a4d7607STejun Heo int nr_unpop = 0, rs, re; 12681a4d7607STejun Heo 12691a4d7607STejun Heo if (!nr_to_pop) 12701a4d7607STejun Heo break; 12711a4d7607STejun Heo 12721a4d7607STejun Heo spin_lock_irq(&pcpu_lock); 12731a4d7607STejun Heo list_for_each_entry(chunk, &pcpu_slot[slot], list) { 1274*8ab16c43SDennis Zhou (Facebook) nr_unpop = chunk->nr_pages - chunk->nr_populated; 12751a4d7607STejun Heo if (nr_unpop) 12761a4d7607STejun Heo break; 12771a4d7607STejun Heo } 12781a4d7607STejun Heo spin_unlock_irq(&pcpu_lock); 12791a4d7607STejun Heo 12801a4d7607STejun Heo if (!nr_unpop) 12811a4d7607STejun Heo continue; 12821a4d7607STejun Heo 12831a4d7607STejun Heo /* @chunk can't go away while pcpu_alloc_mutex is held */ 1284*8ab16c43SDennis Zhou (Facebook) pcpu_for_each_unpop_region(chunk, rs, re, 0, chunk->nr_pages) { 12851a4d7607STejun Heo int nr = min(re - rs, nr_to_pop); 12861a4d7607STejun Heo 12871a4d7607STejun Heo ret = pcpu_populate_chunk(chunk, rs, rs + nr); 12881a4d7607STejun Heo if (!ret) { 12891a4d7607STejun Heo nr_to_pop -= nr; 12901a4d7607STejun Heo spin_lock_irq(&pcpu_lock); 12911a4d7607STejun Heo pcpu_chunk_populated(chunk, rs, rs + nr); 12921a4d7607STejun Heo spin_unlock_irq(&pcpu_lock); 12931a4d7607STejun Heo } else { 12941a4d7607STejun Heo nr_to_pop = 0; 12951a4d7607STejun Heo } 12961a4d7607STejun Heo 12971a4d7607STejun Heo if (!nr_to_pop) 12981a4d7607STejun Heo break; 12991a4d7607STejun Heo } 13001a4d7607STejun Heo } 13011a4d7607STejun Heo 13021a4d7607STejun Heo if (nr_to_pop) { 13031a4d7607STejun Heo /* ran out of chunks to populate, create a new one and retry */ 13041a4d7607STejun Heo chunk = pcpu_create_chunk(); 13051a4d7607STejun Heo if (chunk) { 13061a4d7607STejun Heo spin_lock_irq(&pcpu_lock); 13071a4d7607STejun Heo pcpu_chunk_relocate(chunk, -1); 13081a4d7607STejun Heo spin_unlock_irq(&pcpu_lock); 13091a4d7607STejun Heo goto retry_pop; 13101a4d7607STejun Heo } 13111a4d7607STejun Heo } 13121a4d7607STejun Heo 1313971f3918STejun Heo mutex_unlock(&pcpu_alloc_mutex); 1314a56dbddfSTejun Heo } 1315fbf59bc9STejun Heo 1316fbf59bc9STejun Heo /** 1317fbf59bc9STejun Heo * free_percpu - free percpu area 1318fbf59bc9STejun Heo * @ptr: pointer to area to free 1319fbf59bc9STejun Heo * 1320ccea34b5STejun Heo * Free percpu area @ptr. 1321ccea34b5STejun Heo * 1322ccea34b5STejun Heo * CONTEXT: 1323ccea34b5STejun Heo * Can be called from atomic context. 1324fbf59bc9STejun Heo */ 132543cf38ebSTejun Heo void free_percpu(void __percpu *ptr) 1326fbf59bc9STejun Heo { 1327129182e5SAndrew Morton void *addr; 1328fbf59bc9STejun Heo struct pcpu_chunk *chunk; 1329ccea34b5STejun Heo unsigned long flags; 1330b539b87fSTejun Heo int off, occ_pages; 1331fbf59bc9STejun Heo 1332fbf59bc9STejun Heo if (!ptr) 1333fbf59bc9STejun Heo return; 1334fbf59bc9STejun Heo 1335f528f0b8SCatalin Marinas kmemleak_free_percpu(ptr); 1336f528f0b8SCatalin Marinas 1337129182e5SAndrew Morton addr = __pcpu_ptr_to_addr(ptr); 1338129182e5SAndrew Morton 1339ccea34b5STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 1340fbf59bc9STejun Heo 1341fbf59bc9STejun Heo chunk = pcpu_chunk_addr_search(addr); 1342bba174f5STejun Heo off = addr - chunk->base_addr; 1343fbf59bc9STejun Heo 1344b539b87fSTejun Heo pcpu_free_area(chunk, off, &occ_pages); 1345b539b87fSTejun Heo 1346b539b87fSTejun Heo if (chunk != pcpu_reserved_chunk) 1347b539b87fSTejun Heo pcpu_nr_empty_pop_pages += occ_pages; 1348fbf59bc9STejun Heo 1349a56dbddfSTejun Heo /* if there are more than one fully free chunks, wake up grim reaper */ 1350fbf59bc9STejun Heo if (chunk->free_size == pcpu_unit_size) { 1351fbf59bc9STejun Heo struct pcpu_chunk *pos; 1352fbf59bc9STejun Heo 1353a56dbddfSTejun Heo list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list) 1354fbf59bc9STejun Heo if (pos != chunk) { 13551a4d7607STejun Heo pcpu_schedule_balance_work(); 1356fbf59bc9STejun Heo break; 1357fbf59bc9STejun Heo } 1358fbf59bc9STejun Heo } 1359fbf59bc9STejun Heo 1360df95e795SDennis Zhou trace_percpu_free_percpu(chunk->base_addr, off, ptr); 1361df95e795SDennis Zhou 1362ccea34b5STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 1363fbf59bc9STejun Heo } 1364fbf59bc9STejun Heo EXPORT_SYMBOL_GPL(free_percpu); 1365fbf59bc9STejun Heo 1366383776faSThomas Gleixner bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr) 1367383776faSThomas Gleixner { 1368383776faSThomas Gleixner #ifdef CONFIG_SMP 1369383776faSThomas Gleixner const size_t static_size = __per_cpu_end - __per_cpu_start; 1370383776faSThomas Gleixner void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr); 1371383776faSThomas Gleixner unsigned int cpu; 1372383776faSThomas Gleixner 1373383776faSThomas Gleixner for_each_possible_cpu(cpu) { 1374383776faSThomas Gleixner void *start = per_cpu_ptr(base, cpu); 1375383776faSThomas Gleixner void *va = (void *)addr; 1376383776faSThomas Gleixner 1377383776faSThomas Gleixner if (va >= start && va < start + static_size) { 13788ce371f9SPeter Zijlstra if (can_addr) { 1379383776faSThomas Gleixner *can_addr = (unsigned long) (va - start); 13808ce371f9SPeter Zijlstra *can_addr += (unsigned long) 13818ce371f9SPeter Zijlstra per_cpu_ptr(base, get_boot_cpu_id()); 13828ce371f9SPeter Zijlstra } 1383383776faSThomas Gleixner return true; 1384383776faSThomas Gleixner } 1385383776faSThomas Gleixner } 1386383776faSThomas Gleixner #endif 1387383776faSThomas Gleixner /* on UP, can't distinguish from other static vars, always false */ 1388383776faSThomas Gleixner return false; 1389383776faSThomas Gleixner } 1390383776faSThomas Gleixner 13913b034b0dSVivek Goyal /** 139210fad5e4STejun Heo * is_kernel_percpu_address - test whether address is from static percpu area 139310fad5e4STejun Heo * @addr: address to test 139410fad5e4STejun Heo * 139510fad5e4STejun Heo * Test whether @addr belongs to in-kernel static percpu area. Module 139610fad5e4STejun Heo * static percpu areas are not considered. For those, use 139710fad5e4STejun Heo * is_module_percpu_address(). 139810fad5e4STejun Heo * 139910fad5e4STejun Heo * RETURNS: 140010fad5e4STejun Heo * %true if @addr is from in-kernel static percpu area, %false otherwise. 140110fad5e4STejun Heo */ 140210fad5e4STejun Heo bool is_kernel_percpu_address(unsigned long addr) 140310fad5e4STejun Heo { 1404383776faSThomas Gleixner return __is_kernel_percpu_address(addr, NULL); 140510fad5e4STejun Heo } 140610fad5e4STejun Heo 140710fad5e4STejun Heo /** 14083b034b0dSVivek Goyal * per_cpu_ptr_to_phys - convert translated percpu address to physical address 14093b034b0dSVivek Goyal * @addr: the address to be converted to physical address 14103b034b0dSVivek Goyal * 14113b034b0dSVivek Goyal * Given @addr which is dereferenceable address obtained via one of 14123b034b0dSVivek Goyal * percpu access macros, this function translates it into its physical 14133b034b0dSVivek Goyal * address. The caller is responsible for ensuring @addr stays valid 14143b034b0dSVivek Goyal * until this function finishes. 14153b034b0dSVivek Goyal * 141667589c71SDave Young * percpu allocator has special setup for the first chunk, which currently 141767589c71SDave Young * supports either embedding in linear address space or vmalloc mapping, 141867589c71SDave Young * and, from the second one, the backing allocator (currently either vm or 141967589c71SDave Young * km) provides translation. 142067589c71SDave Young * 1421bffc4375SYannick Guerrini * The addr can be translated simply without checking if it falls into the 142267589c71SDave Young * first chunk. But the current code reflects better how percpu allocator 142367589c71SDave Young * actually works, and the verification can discover both bugs in percpu 142467589c71SDave Young * allocator itself and per_cpu_ptr_to_phys() callers. So we keep current 142567589c71SDave Young * code. 142667589c71SDave Young * 14273b034b0dSVivek Goyal * RETURNS: 14283b034b0dSVivek Goyal * The physical address for @addr. 14293b034b0dSVivek Goyal */ 14303b034b0dSVivek Goyal phys_addr_t per_cpu_ptr_to_phys(void *addr) 14313b034b0dSVivek Goyal { 14329983b6f0STejun Heo void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr); 14339983b6f0STejun Heo bool in_first_chunk = false; 1434a855b84cSTejun Heo unsigned long first_low, first_high; 14359983b6f0STejun Heo unsigned int cpu; 14369983b6f0STejun Heo 14379983b6f0STejun Heo /* 1438a855b84cSTejun Heo * The following test on unit_low/high isn't strictly 14399983b6f0STejun Heo * necessary but will speed up lookups of addresses which 14409983b6f0STejun Heo * aren't in the first chunk. 1441c0ebfdc3SDennis Zhou (Facebook) * 1442c0ebfdc3SDennis Zhou (Facebook) * The address check is against full chunk sizes. pcpu_base_addr 1443c0ebfdc3SDennis Zhou (Facebook) * points to the beginning of the first chunk including the 1444c0ebfdc3SDennis Zhou (Facebook) * static region. Assumes good intent as the first chunk may 1445c0ebfdc3SDennis Zhou (Facebook) * not be full (ie. < pcpu_unit_pages in size). 14469983b6f0STejun Heo */ 1447c0ebfdc3SDennis Zhou (Facebook) first_low = (unsigned long)pcpu_base_addr + 1448c0ebfdc3SDennis Zhou (Facebook) pcpu_unit_page_offset(pcpu_low_unit_cpu, 0); 1449c0ebfdc3SDennis Zhou (Facebook) first_high = (unsigned long)pcpu_base_addr + 1450c0ebfdc3SDennis Zhou (Facebook) pcpu_unit_page_offset(pcpu_high_unit_cpu, pcpu_unit_pages); 1451a855b84cSTejun Heo if ((unsigned long)addr >= first_low && 1452a855b84cSTejun Heo (unsigned long)addr < first_high) { 14539983b6f0STejun Heo for_each_possible_cpu(cpu) { 14549983b6f0STejun Heo void *start = per_cpu_ptr(base, cpu); 14559983b6f0STejun Heo 14569983b6f0STejun Heo if (addr >= start && addr < start + pcpu_unit_size) { 14579983b6f0STejun Heo in_first_chunk = true; 14589983b6f0STejun Heo break; 14599983b6f0STejun Heo } 14609983b6f0STejun Heo } 14619983b6f0STejun Heo } 14629983b6f0STejun Heo 14639983b6f0STejun Heo if (in_first_chunk) { 1464eac522efSDavid Howells if (!is_vmalloc_addr(addr)) 14653b034b0dSVivek Goyal return __pa(addr); 14663b034b0dSVivek Goyal else 14679f57bd4dSEugene Surovegin return page_to_phys(vmalloc_to_page(addr)) + 14689f57bd4dSEugene Surovegin offset_in_page(addr); 1469020ec653STejun Heo } else 14709f57bd4dSEugene Surovegin return page_to_phys(pcpu_addr_to_page(addr)) + 14719f57bd4dSEugene Surovegin offset_in_page(addr); 14723b034b0dSVivek Goyal } 14733b034b0dSVivek Goyal 1474fbf59bc9STejun Heo /** 1475fd1e8a1fSTejun Heo * pcpu_alloc_alloc_info - allocate percpu allocation info 1476fd1e8a1fSTejun Heo * @nr_groups: the number of groups 1477fd1e8a1fSTejun Heo * @nr_units: the number of units 1478033e48fbSTejun Heo * 1479fd1e8a1fSTejun Heo * Allocate ai which is large enough for @nr_groups groups containing 1480fd1e8a1fSTejun Heo * @nr_units units. The returned ai's groups[0].cpu_map points to the 1481fd1e8a1fSTejun Heo * cpu_map array which is long enough for @nr_units and filled with 1482fd1e8a1fSTejun Heo * NR_CPUS. It's the caller's responsibility to initialize cpu_map 1483fd1e8a1fSTejun Heo * pointer of other groups. 1484033e48fbSTejun Heo * 1485033e48fbSTejun Heo * RETURNS: 1486fd1e8a1fSTejun Heo * Pointer to the allocated pcpu_alloc_info on success, NULL on 1487fd1e8a1fSTejun Heo * failure. 1488033e48fbSTejun Heo */ 1489fd1e8a1fSTejun Heo struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, 1490fd1e8a1fSTejun Heo int nr_units) 1491fd1e8a1fSTejun Heo { 1492fd1e8a1fSTejun Heo struct pcpu_alloc_info *ai; 1493fd1e8a1fSTejun Heo size_t base_size, ai_size; 1494fd1e8a1fSTejun Heo void *ptr; 1495fd1e8a1fSTejun Heo int unit; 1496fd1e8a1fSTejun Heo 1497fd1e8a1fSTejun Heo base_size = ALIGN(sizeof(*ai) + nr_groups * sizeof(ai->groups[0]), 1498fd1e8a1fSTejun Heo __alignof__(ai->groups[0].cpu_map[0])); 1499fd1e8a1fSTejun Heo ai_size = base_size + nr_units * sizeof(ai->groups[0].cpu_map[0]); 1500fd1e8a1fSTejun Heo 1501999c17e3SSantosh Shilimkar ptr = memblock_virt_alloc_nopanic(PFN_ALIGN(ai_size), 0); 1502fd1e8a1fSTejun Heo if (!ptr) 1503fd1e8a1fSTejun Heo return NULL; 1504fd1e8a1fSTejun Heo ai = ptr; 1505fd1e8a1fSTejun Heo ptr += base_size; 1506fd1e8a1fSTejun Heo 1507fd1e8a1fSTejun Heo ai->groups[0].cpu_map = ptr; 1508fd1e8a1fSTejun Heo 1509fd1e8a1fSTejun Heo for (unit = 0; unit < nr_units; unit++) 1510fd1e8a1fSTejun Heo ai->groups[0].cpu_map[unit] = NR_CPUS; 1511fd1e8a1fSTejun Heo 1512fd1e8a1fSTejun Heo ai->nr_groups = nr_groups; 1513fd1e8a1fSTejun Heo ai->__ai_size = PFN_ALIGN(ai_size); 1514fd1e8a1fSTejun Heo 1515fd1e8a1fSTejun Heo return ai; 1516fd1e8a1fSTejun Heo } 1517fd1e8a1fSTejun Heo 1518fd1e8a1fSTejun Heo /** 1519fd1e8a1fSTejun Heo * pcpu_free_alloc_info - free percpu allocation info 1520fd1e8a1fSTejun Heo * @ai: pcpu_alloc_info to free 1521fd1e8a1fSTejun Heo * 1522fd1e8a1fSTejun Heo * Free @ai which was allocated by pcpu_alloc_alloc_info(). 1523fd1e8a1fSTejun Heo */ 1524fd1e8a1fSTejun Heo void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai) 1525fd1e8a1fSTejun Heo { 1526999c17e3SSantosh Shilimkar memblock_free_early(__pa(ai), ai->__ai_size); 1527fd1e8a1fSTejun Heo } 1528fd1e8a1fSTejun Heo 1529fd1e8a1fSTejun Heo /** 1530fd1e8a1fSTejun Heo * pcpu_dump_alloc_info - print out information about pcpu_alloc_info 1531fd1e8a1fSTejun Heo * @lvl: loglevel 1532fd1e8a1fSTejun Heo * @ai: allocation info to dump 1533fd1e8a1fSTejun Heo * 1534fd1e8a1fSTejun Heo * Print out information about @ai using loglevel @lvl. 1535fd1e8a1fSTejun Heo */ 1536fd1e8a1fSTejun Heo static void pcpu_dump_alloc_info(const char *lvl, 1537fd1e8a1fSTejun Heo const struct pcpu_alloc_info *ai) 1538033e48fbSTejun Heo { 1539fd1e8a1fSTejun Heo int group_width = 1, cpu_width = 1, width; 1540033e48fbSTejun Heo char empty_str[] = "--------"; 1541fd1e8a1fSTejun Heo int alloc = 0, alloc_end = 0; 1542fd1e8a1fSTejun Heo int group, v; 1543fd1e8a1fSTejun Heo int upa, apl; /* units per alloc, allocs per line */ 1544033e48fbSTejun Heo 1545fd1e8a1fSTejun Heo v = ai->nr_groups; 1546033e48fbSTejun Heo while (v /= 10) 1547fd1e8a1fSTejun Heo group_width++; 1548033e48fbSTejun Heo 1549fd1e8a1fSTejun Heo v = num_possible_cpus(); 1550fd1e8a1fSTejun Heo while (v /= 10) 1551fd1e8a1fSTejun Heo cpu_width++; 1552fd1e8a1fSTejun Heo empty_str[min_t(int, cpu_width, sizeof(empty_str) - 1)] = '\0'; 1553033e48fbSTejun Heo 1554fd1e8a1fSTejun Heo upa = ai->alloc_size / ai->unit_size; 1555fd1e8a1fSTejun Heo width = upa * (cpu_width + 1) + group_width + 3; 1556fd1e8a1fSTejun Heo apl = rounddown_pow_of_two(max(60 / width, 1)); 1557033e48fbSTejun Heo 1558fd1e8a1fSTejun Heo printk("%spcpu-alloc: s%zu r%zu d%zu u%zu alloc=%zu*%zu", 1559fd1e8a1fSTejun Heo lvl, ai->static_size, ai->reserved_size, ai->dyn_size, 1560fd1e8a1fSTejun Heo ai->unit_size, ai->alloc_size / ai->atom_size, ai->atom_size); 1561fd1e8a1fSTejun Heo 1562fd1e8a1fSTejun Heo for (group = 0; group < ai->nr_groups; group++) { 1563fd1e8a1fSTejun Heo const struct pcpu_group_info *gi = &ai->groups[group]; 1564fd1e8a1fSTejun Heo int unit = 0, unit_end = 0; 1565fd1e8a1fSTejun Heo 1566fd1e8a1fSTejun Heo BUG_ON(gi->nr_units % upa); 1567fd1e8a1fSTejun Heo for (alloc_end += gi->nr_units / upa; 1568fd1e8a1fSTejun Heo alloc < alloc_end; alloc++) { 1569fd1e8a1fSTejun Heo if (!(alloc % apl)) { 15701170532bSJoe Perches pr_cont("\n"); 1571fd1e8a1fSTejun Heo printk("%spcpu-alloc: ", lvl); 1572033e48fbSTejun Heo } 15731170532bSJoe Perches pr_cont("[%0*d] ", group_width, group); 1574fd1e8a1fSTejun Heo 1575fd1e8a1fSTejun Heo for (unit_end += upa; unit < unit_end; unit++) 1576fd1e8a1fSTejun Heo if (gi->cpu_map[unit] != NR_CPUS) 15771170532bSJoe Perches pr_cont("%0*d ", 15781170532bSJoe Perches cpu_width, gi->cpu_map[unit]); 1579033e48fbSTejun Heo else 15801170532bSJoe Perches pr_cont("%s ", empty_str); 1581033e48fbSTejun Heo } 1582fd1e8a1fSTejun Heo } 15831170532bSJoe Perches pr_cont("\n"); 1584033e48fbSTejun Heo } 1585033e48fbSTejun Heo 1586fbf59bc9STejun Heo /** 15878d408b4bSTejun Heo * pcpu_setup_first_chunk - initialize the first percpu chunk 1588fd1e8a1fSTejun Heo * @ai: pcpu_alloc_info describing how to percpu area is shaped 158938a6be52STejun Heo * @base_addr: mapped address 1590fbf59bc9STejun Heo * 15918d408b4bSTejun Heo * Initialize the first percpu chunk which contains the kernel static 15928d408b4bSTejun Heo * perpcu area. This function is to be called from arch percpu area 159338a6be52STejun Heo * setup path. 15948d408b4bSTejun Heo * 1595fd1e8a1fSTejun Heo * @ai contains all information necessary to initialize the first 1596fd1e8a1fSTejun Heo * chunk and prime the dynamic percpu allocator. 15978d408b4bSTejun Heo * 1598fd1e8a1fSTejun Heo * @ai->static_size is the size of static percpu area. 1599fd1e8a1fSTejun Heo * 1600fd1e8a1fSTejun Heo * @ai->reserved_size, if non-zero, specifies the amount of bytes to 1601edcb4639STejun Heo * reserve after the static area in the first chunk. This reserves 1602edcb4639STejun Heo * the first chunk such that it's available only through reserved 1603edcb4639STejun Heo * percpu allocation. This is primarily used to serve module percpu 1604edcb4639STejun Heo * static areas on architectures where the addressing model has 1605edcb4639STejun Heo * limited offset range for symbol relocations to guarantee module 1606edcb4639STejun Heo * percpu symbols fall inside the relocatable range. 1607edcb4639STejun Heo * 1608fd1e8a1fSTejun Heo * @ai->dyn_size determines the number of bytes available for dynamic 1609fd1e8a1fSTejun Heo * allocation in the first chunk. The area between @ai->static_size + 1610fd1e8a1fSTejun Heo * @ai->reserved_size + @ai->dyn_size and @ai->unit_size is unused. 16116074d5b0STejun Heo * 1612fd1e8a1fSTejun Heo * @ai->unit_size specifies unit size and must be aligned to PAGE_SIZE 1613fd1e8a1fSTejun Heo * and equal to or larger than @ai->static_size + @ai->reserved_size + 1614fd1e8a1fSTejun Heo * @ai->dyn_size. 16158d408b4bSTejun Heo * 1616fd1e8a1fSTejun Heo * @ai->atom_size is the allocation atom size and used as alignment 1617fd1e8a1fSTejun Heo * for vm areas. 16188d408b4bSTejun Heo * 1619fd1e8a1fSTejun Heo * @ai->alloc_size is the allocation size and always multiple of 1620fd1e8a1fSTejun Heo * @ai->atom_size. This is larger than @ai->atom_size if 1621fd1e8a1fSTejun Heo * @ai->unit_size is larger than @ai->atom_size. 1622fd1e8a1fSTejun Heo * 1623fd1e8a1fSTejun Heo * @ai->nr_groups and @ai->groups describe virtual memory layout of 1624fd1e8a1fSTejun Heo * percpu areas. Units which should be colocated are put into the 1625fd1e8a1fSTejun Heo * same group. Dynamic VM areas will be allocated according to these 1626fd1e8a1fSTejun Heo * groupings. If @ai->nr_groups is zero, a single group containing 1627fd1e8a1fSTejun Heo * all units is assumed. 16288d408b4bSTejun Heo * 162938a6be52STejun Heo * The caller should have mapped the first chunk at @base_addr and 163038a6be52STejun Heo * copied static data to each unit. 1631fbf59bc9STejun Heo * 1632c0ebfdc3SDennis Zhou (Facebook) * The first chunk will always contain a static and a dynamic region. 1633c0ebfdc3SDennis Zhou (Facebook) * However, the static region is not managed by any chunk. If the first 1634c0ebfdc3SDennis Zhou (Facebook) * chunk also contains a reserved region, it is served by two chunks - 1635c0ebfdc3SDennis Zhou (Facebook) * one for the reserved region and one for the dynamic region. They 1636c0ebfdc3SDennis Zhou (Facebook) * share the same vm, but use offset regions in the area allocation map. 1637c0ebfdc3SDennis Zhou (Facebook) * The chunk serving the dynamic region is circulated in the chunk slots 1638c0ebfdc3SDennis Zhou (Facebook) * and available for dynamic allocation like any other chunk. 1639edcb4639STejun Heo * 1640fbf59bc9STejun Heo * RETURNS: 1641fb435d52STejun Heo * 0 on success, -errno on failure. 1642fbf59bc9STejun Heo */ 1643fb435d52STejun Heo int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, 1644fd1e8a1fSTejun Heo void *base_addr) 1645fbf59bc9STejun Heo { 1646099a19d9STejun Heo static int smap[PERCPU_DYNAMIC_EARLY_SLOTS] __initdata; 1647099a19d9STejun Heo static int dmap[PERCPU_DYNAMIC_EARLY_SLOTS] __initdata; 1648b9c39442SDennis Zhou (Facebook) size_t size_sum = ai->static_size + ai->reserved_size + ai->dyn_size; 16490c4169c3SDennis Zhou (Facebook) struct pcpu_chunk *chunk; 16506563297cSTejun Heo unsigned long *group_offsets; 16516563297cSTejun Heo size_t *group_sizes; 1652fb435d52STejun Heo unsigned long *unit_off; 1653fbf59bc9STejun Heo unsigned int cpu; 1654fd1e8a1fSTejun Heo int *unit_map; 1655fd1e8a1fSTejun Heo int group, unit, i; 1656c0ebfdc3SDennis Zhou (Facebook) int map_size; 1657c0ebfdc3SDennis Zhou (Facebook) unsigned long tmp_addr; 1658fbf59bc9STejun Heo 1659635b75fcSTejun Heo #define PCPU_SETUP_BUG_ON(cond) do { \ 1660635b75fcSTejun Heo if (unlikely(cond)) { \ 1661870d4b12SJoe Perches pr_emerg("failed to initialize, %s\n", #cond); \ 1662870d4b12SJoe Perches pr_emerg("cpu_possible_mask=%*pb\n", \ 1663807de073STejun Heo cpumask_pr_args(cpu_possible_mask)); \ 1664635b75fcSTejun Heo pcpu_dump_alloc_info(KERN_EMERG, ai); \ 1665635b75fcSTejun Heo BUG(); \ 1666635b75fcSTejun Heo } \ 1667635b75fcSTejun Heo } while (0) 1668635b75fcSTejun Heo 16692f39e637STejun Heo /* sanity checks */ 1670635b75fcSTejun Heo PCPU_SETUP_BUG_ON(ai->nr_groups <= 0); 1671bbddff05STejun Heo #ifdef CONFIG_SMP 1672635b75fcSTejun Heo PCPU_SETUP_BUG_ON(!ai->static_size); 1673f09f1243SAlexander Kuleshov PCPU_SETUP_BUG_ON(offset_in_page(__per_cpu_start)); 1674bbddff05STejun Heo #endif 1675635b75fcSTejun Heo PCPU_SETUP_BUG_ON(!base_addr); 1676f09f1243SAlexander Kuleshov PCPU_SETUP_BUG_ON(offset_in_page(base_addr)); 1677635b75fcSTejun Heo PCPU_SETUP_BUG_ON(ai->unit_size < size_sum); 1678f09f1243SAlexander Kuleshov PCPU_SETUP_BUG_ON(offset_in_page(ai->unit_size)); 1679635b75fcSTejun Heo PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE); 1680099a19d9STejun Heo PCPU_SETUP_BUG_ON(ai->dyn_size < PERCPU_DYNAMIC_EARLY_SIZE); 1681fb29a2ccSDennis Zhou (Facebook) PCPU_SETUP_BUG_ON(!ai->dyn_size); 16829f645532STejun Heo PCPU_SETUP_BUG_ON(pcpu_verify_alloc_info(ai) < 0); 16838d408b4bSTejun Heo 16846563297cSTejun Heo /* process group information and build config tables accordingly */ 1685999c17e3SSantosh Shilimkar group_offsets = memblock_virt_alloc(ai->nr_groups * 1686999c17e3SSantosh Shilimkar sizeof(group_offsets[0]), 0); 1687999c17e3SSantosh Shilimkar group_sizes = memblock_virt_alloc(ai->nr_groups * 1688999c17e3SSantosh Shilimkar sizeof(group_sizes[0]), 0); 1689999c17e3SSantosh Shilimkar unit_map = memblock_virt_alloc(nr_cpu_ids * sizeof(unit_map[0]), 0); 1690999c17e3SSantosh Shilimkar unit_off = memblock_virt_alloc(nr_cpu_ids * sizeof(unit_off[0]), 0); 16912f39e637STejun Heo 1692fd1e8a1fSTejun Heo for (cpu = 0; cpu < nr_cpu_ids; cpu++) 1693ffe0d5a5STejun Heo unit_map[cpu] = UINT_MAX; 1694a855b84cSTejun Heo 1695a855b84cSTejun Heo pcpu_low_unit_cpu = NR_CPUS; 1696a855b84cSTejun Heo pcpu_high_unit_cpu = NR_CPUS; 16972f39e637STejun Heo 1698fd1e8a1fSTejun Heo for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) { 1699fd1e8a1fSTejun Heo const struct pcpu_group_info *gi = &ai->groups[group]; 17002f39e637STejun Heo 17016563297cSTejun Heo group_offsets[group] = gi->base_offset; 17026563297cSTejun Heo group_sizes[group] = gi->nr_units * ai->unit_size; 17036563297cSTejun Heo 1704fd1e8a1fSTejun Heo for (i = 0; i < gi->nr_units; i++) { 1705fd1e8a1fSTejun Heo cpu = gi->cpu_map[i]; 1706fd1e8a1fSTejun Heo if (cpu == NR_CPUS) 1707fd1e8a1fSTejun Heo continue; 1708fd1e8a1fSTejun Heo 17099f295664SDan Carpenter PCPU_SETUP_BUG_ON(cpu >= nr_cpu_ids); 1710635b75fcSTejun Heo PCPU_SETUP_BUG_ON(!cpu_possible(cpu)); 1711635b75fcSTejun Heo PCPU_SETUP_BUG_ON(unit_map[cpu] != UINT_MAX); 1712fd1e8a1fSTejun Heo 1713fd1e8a1fSTejun Heo unit_map[cpu] = unit + i; 1714fb435d52STejun Heo unit_off[cpu] = gi->base_offset + i * ai->unit_size; 1715fb435d52STejun Heo 1716a855b84cSTejun Heo /* determine low/high unit_cpu */ 1717a855b84cSTejun Heo if (pcpu_low_unit_cpu == NR_CPUS || 1718a855b84cSTejun Heo unit_off[cpu] < unit_off[pcpu_low_unit_cpu]) 1719a855b84cSTejun Heo pcpu_low_unit_cpu = cpu; 1720a855b84cSTejun Heo if (pcpu_high_unit_cpu == NR_CPUS || 1721a855b84cSTejun Heo unit_off[cpu] > unit_off[pcpu_high_unit_cpu]) 1722a855b84cSTejun Heo pcpu_high_unit_cpu = cpu; 17230fc0531eSLinus Torvalds } 17240fc0531eSLinus Torvalds } 1725fd1e8a1fSTejun Heo pcpu_nr_units = unit; 17262f39e637STejun Heo 17272f39e637STejun Heo for_each_possible_cpu(cpu) 1728635b75fcSTejun Heo PCPU_SETUP_BUG_ON(unit_map[cpu] == UINT_MAX); 1729635b75fcSTejun Heo 1730635b75fcSTejun Heo /* we're done parsing the input, undefine BUG macro and dump config */ 1731635b75fcSTejun Heo #undef PCPU_SETUP_BUG_ON 1732bcbea798STejun Heo pcpu_dump_alloc_info(KERN_DEBUG, ai); 17332f39e637STejun Heo 17346563297cSTejun Heo pcpu_nr_groups = ai->nr_groups; 17356563297cSTejun Heo pcpu_group_offsets = group_offsets; 17366563297cSTejun Heo pcpu_group_sizes = group_sizes; 1737fd1e8a1fSTejun Heo pcpu_unit_map = unit_map; 1738fb435d52STejun Heo pcpu_unit_offsets = unit_off; 17392f39e637STejun Heo 17402f39e637STejun Heo /* determine basic parameters */ 1741fd1e8a1fSTejun Heo pcpu_unit_pages = ai->unit_size >> PAGE_SHIFT; 1742d9b55eebSTejun Heo pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT; 17436563297cSTejun Heo pcpu_atom_size = ai->atom_size; 1744ce3141a2STejun Heo pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) + 1745ce3141a2STejun Heo BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long); 1746cafe8816STejun Heo 174730a5b536SDennis Zhou pcpu_stats_save_ai(ai); 174830a5b536SDennis Zhou 1749d9b55eebSTejun Heo /* 1750d9b55eebSTejun Heo * Allocate chunk slots. The additional last slot is for 1751d9b55eebSTejun Heo * empty chunks. 1752d9b55eebSTejun Heo */ 1753d9b55eebSTejun Heo pcpu_nr_slots = __pcpu_size_to_slot(pcpu_unit_size) + 2; 1754999c17e3SSantosh Shilimkar pcpu_slot = memblock_virt_alloc( 1755999c17e3SSantosh Shilimkar pcpu_nr_slots * sizeof(pcpu_slot[0]), 0); 1756fbf59bc9STejun Heo for (i = 0; i < pcpu_nr_slots; i++) 1757fbf59bc9STejun Heo INIT_LIST_HEAD(&pcpu_slot[i]); 1758fbf59bc9STejun Heo 1759edcb4639STejun Heo /* 1760c0ebfdc3SDennis Zhou (Facebook) * Initialize first chunk. 1761c0ebfdc3SDennis Zhou (Facebook) * If the reserved_size is non-zero, this initializes the reserved 1762c0ebfdc3SDennis Zhou (Facebook) * chunk. If the reserved_size is zero, the reserved chunk is NULL 1763c0ebfdc3SDennis Zhou (Facebook) * and the dynamic region is initialized here. The first chunk, 1764c0ebfdc3SDennis Zhou (Facebook) * pcpu_first_chunk, will always point to the chunk that serves 1765c0ebfdc3SDennis Zhou (Facebook) * the dynamic region. 1766edcb4639STejun Heo */ 1767c0ebfdc3SDennis Zhou (Facebook) tmp_addr = (unsigned long)base_addr + ai->static_size; 176810edf5b0SDennis Zhou (Facebook) map_size = ai->reserved_size ?: ai->dyn_size; 1769c0ebfdc3SDennis Zhou (Facebook) chunk = pcpu_alloc_first_chunk(tmp_addr, map_size, smap, 17700c4169c3SDennis Zhou (Facebook) ARRAY_SIZE(smap)); 177161ace7faSTejun Heo 1772edcb4639STejun Heo /* init dynamic chunk if necessary */ 1773b9c39442SDennis Zhou (Facebook) if (ai->reserved_size) { 17740c4169c3SDennis Zhou (Facebook) pcpu_reserved_chunk = chunk; 1775b9c39442SDennis Zhou (Facebook) 1776c0ebfdc3SDennis Zhou (Facebook) tmp_addr = (unsigned long)base_addr + ai->static_size + 1777c0ebfdc3SDennis Zhou (Facebook) ai->reserved_size; 177810edf5b0SDennis Zhou (Facebook) map_size = ai->dyn_size; 1779c0ebfdc3SDennis Zhou (Facebook) chunk = pcpu_alloc_first_chunk(tmp_addr, map_size, dmap, 178010edf5b0SDennis Zhou (Facebook) ARRAY_SIZE(dmap)); 1781edcb4639STejun Heo } 1782edcb4639STejun Heo 17832441d15cSTejun Heo /* link the first chunk in */ 17840c4169c3SDennis Zhou (Facebook) pcpu_first_chunk = chunk; 1785e2266705SDennis Zhou (Facebook) i = (pcpu_first_chunk->start_offset) ? 1 : 0; 1786b539b87fSTejun Heo pcpu_nr_empty_pop_pages += 1787e2266705SDennis Zhou (Facebook) pcpu_count_occupied_pages(pcpu_first_chunk, i); 1788ae9e6bc9STejun Heo pcpu_chunk_relocate(pcpu_first_chunk, -1); 1789fbf59bc9STejun Heo 179030a5b536SDennis Zhou pcpu_stats_chunk_alloc(); 1791df95e795SDennis Zhou trace_percpu_create_chunk(base_addr); 179230a5b536SDennis Zhou 1793fbf59bc9STejun Heo /* we're done */ 1794bba174f5STejun Heo pcpu_base_addr = base_addr; 1795fb435d52STejun Heo return 0; 1796fbf59bc9STejun Heo } 179766c3a757STejun Heo 1798bbddff05STejun Heo #ifdef CONFIG_SMP 1799bbddff05STejun Heo 180017f3609cSAndi Kleen const char * const pcpu_fc_names[PCPU_FC_NR] __initconst = { 1801f58dc01bSTejun Heo [PCPU_FC_AUTO] = "auto", 1802f58dc01bSTejun Heo [PCPU_FC_EMBED] = "embed", 1803f58dc01bSTejun Heo [PCPU_FC_PAGE] = "page", 1804f58dc01bSTejun Heo }; 180566c3a757STejun Heo 1806f58dc01bSTejun Heo enum pcpu_fc pcpu_chosen_fc __initdata = PCPU_FC_AUTO; 1807f58dc01bSTejun Heo 1808f58dc01bSTejun Heo static int __init percpu_alloc_setup(char *str) 180966c3a757STejun Heo { 18105479c78aSCyrill Gorcunov if (!str) 18115479c78aSCyrill Gorcunov return -EINVAL; 18125479c78aSCyrill Gorcunov 1813f58dc01bSTejun Heo if (0) 1814f58dc01bSTejun Heo /* nada */; 1815f58dc01bSTejun Heo #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK 1816f58dc01bSTejun Heo else if (!strcmp(str, "embed")) 1817f58dc01bSTejun Heo pcpu_chosen_fc = PCPU_FC_EMBED; 1818f58dc01bSTejun Heo #endif 1819f58dc01bSTejun Heo #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK 1820f58dc01bSTejun Heo else if (!strcmp(str, "page")) 1821f58dc01bSTejun Heo pcpu_chosen_fc = PCPU_FC_PAGE; 1822f58dc01bSTejun Heo #endif 1823f58dc01bSTejun Heo else 1824870d4b12SJoe Perches pr_warn("unknown allocator %s specified\n", str); 182566c3a757STejun Heo 1826f58dc01bSTejun Heo return 0; 182766c3a757STejun Heo } 1828f58dc01bSTejun Heo early_param("percpu_alloc", percpu_alloc_setup); 182966c3a757STejun Heo 18303c9a024fSTejun Heo /* 18313c9a024fSTejun Heo * pcpu_embed_first_chunk() is used by the generic percpu setup. 18323c9a024fSTejun Heo * Build it if needed by the arch config or the generic setup is going 18333c9a024fSTejun Heo * to be used. 18343c9a024fSTejun Heo */ 183508fc4580STejun Heo #if defined(CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK) || \ 183608fc4580STejun Heo !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) 18373c9a024fSTejun Heo #define BUILD_EMBED_FIRST_CHUNK 18383c9a024fSTejun Heo #endif 18393c9a024fSTejun Heo 18403c9a024fSTejun Heo /* build pcpu_page_first_chunk() iff needed by the arch config */ 18413c9a024fSTejun Heo #if defined(CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK) 18423c9a024fSTejun Heo #define BUILD_PAGE_FIRST_CHUNK 18433c9a024fSTejun Heo #endif 18443c9a024fSTejun Heo 18453c9a024fSTejun Heo /* pcpu_build_alloc_info() is used by both embed and page first chunk */ 18463c9a024fSTejun Heo #if defined(BUILD_EMBED_FIRST_CHUNK) || defined(BUILD_PAGE_FIRST_CHUNK) 18473c9a024fSTejun Heo /** 1848fbf59bc9STejun Heo * pcpu_build_alloc_info - build alloc_info considering distances between CPUs 1849fbf59bc9STejun Heo * @reserved_size: the size of reserved percpu area in bytes 1850fbf59bc9STejun Heo * @dyn_size: minimum free size for dynamic allocation in bytes 1851fbf59bc9STejun Heo * @atom_size: allocation atom size 1852fbf59bc9STejun Heo * @cpu_distance_fn: callback to determine distance between cpus, optional 1853fbf59bc9STejun Heo * 1854fbf59bc9STejun Heo * This function determines grouping of units, their mappings to cpus 1855fbf59bc9STejun Heo * and other parameters considering needed percpu size, allocation 1856fbf59bc9STejun Heo * atom size and distances between CPUs. 1857fbf59bc9STejun Heo * 1858bffc4375SYannick Guerrini * Groups are always multiples of atom size and CPUs which are of 1859fbf59bc9STejun Heo * LOCAL_DISTANCE both ways are grouped together and share space for 1860fbf59bc9STejun Heo * units in the same group. The returned configuration is guaranteed 1861fbf59bc9STejun Heo * to have CPUs on different nodes on different groups and >=75% usage 1862fbf59bc9STejun Heo * of allocated virtual address space. 1863fbf59bc9STejun Heo * 1864fbf59bc9STejun Heo * RETURNS: 1865fbf59bc9STejun Heo * On success, pointer to the new allocation_info is returned. On 1866fbf59bc9STejun Heo * failure, ERR_PTR value is returned. 1867fbf59bc9STejun Heo */ 1868fbf59bc9STejun Heo static struct pcpu_alloc_info * __init pcpu_build_alloc_info( 1869fbf59bc9STejun Heo size_t reserved_size, size_t dyn_size, 1870fbf59bc9STejun Heo size_t atom_size, 1871fbf59bc9STejun Heo pcpu_fc_cpu_distance_fn_t cpu_distance_fn) 1872fbf59bc9STejun Heo { 1873fbf59bc9STejun Heo static int group_map[NR_CPUS] __initdata; 1874fbf59bc9STejun Heo static int group_cnt[NR_CPUS] __initdata; 1875fbf59bc9STejun Heo const size_t static_size = __per_cpu_end - __per_cpu_start; 1876fbf59bc9STejun Heo int nr_groups = 1, nr_units = 0; 1877fbf59bc9STejun Heo size_t size_sum, min_unit_size, alloc_size; 1878fbf59bc9STejun Heo int upa, max_upa, uninitialized_var(best_upa); /* units_per_alloc */ 1879fbf59bc9STejun Heo int last_allocs, group, unit; 1880fbf59bc9STejun Heo unsigned int cpu, tcpu; 1881fbf59bc9STejun Heo struct pcpu_alloc_info *ai; 1882fbf59bc9STejun Heo unsigned int *cpu_map; 1883fbf59bc9STejun Heo 1884fbf59bc9STejun Heo /* this function may be called multiple times */ 1885fbf59bc9STejun Heo memset(group_map, 0, sizeof(group_map)); 1886fbf59bc9STejun Heo memset(group_cnt, 0, sizeof(group_cnt)); 1887fbf59bc9STejun Heo 1888fbf59bc9STejun Heo /* calculate size_sum and ensure dyn_size is enough for early alloc */ 1889fbf59bc9STejun Heo size_sum = PFN_ALIGN(static_size + reserved_size + 1890fbf59bc9STejun Heo max_t(size_t, dyn_size, PERCPU_DYNAMIC_EARLY_SIZE)); 1891fbf59bc9STejun Heo dyn_size = size_sum - static_size - reserved_size; 1892fbf59bc9STejun Heo 1893fbf59bc9STejun Heo /* 1894fbf59bc9STejun Heo * Determine min_unit_size, alloc_size and max_upa such that 1895fbf59bc9STejun Heo * alloc_size is multiple of atom_size and is the smallest 189625985edcSLucas De Marchi * which can accommodate 4k aligned segments which are equal to 1897fbf59bc9STejun Heo * or larger than min_unit_size. 1898fbf59bc9STejun Heo */ 1899fbf59bc9STejun Heo min_unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE); 1900fbf59bc9STejun Heo 19019c015162SDennis Zhou (Facebook) /* determine the maximum # of units that can fit in an allocation */ 1902fbf59bc9STejun Heo alloc_size = roundup(min_unit_size, atom_size); 1903fbf59bc9STejun Heo upa = alloc_size / min_unit_size; 1904f09f1243SAlexander Kuleshov while (alloc_size % upa || (offset_in_page(alloc_size / upa))) 1905fbf59bc9STejun Heo upa--; 1906fbf59bc9STejun Heo max_upa = upa; 1907fbf59bc9STejun Heo 1908fbf59bc9STejun Heo /* group cpus according to their proximity */ 1909fbf59bc9STejun Heo for_each_possible_cpu(cpu) { 1910fbf59bc9STejun Heo group = 0; 1911fbf59bc9STejun Heo next_group: 1912fbf59bc9STejun Heo for_each_possible_cpu(tcpu) { 1913fbf59bc9STejun Heo if (cpu == tcpu) 1914fbf59bc9STejun Heo break; 1915fbf59bc9STejun Heo if (group_map[tcpu] == group && cpu_distance_fn && 1916fbf59bc9STejun Heo (cpu_distance_fn(cpu, tcpu) > LOCAL_DISTANCE || 1917fbf59bc9STejun Heo cpu_distance_fn(tcpu, cpu) > LOCAL_DISTANCE)) { 1918fbf59bc9STejun Heo group++; 1919fbf59bc9STejun Heo nr_groups = max(nr_groups, group + 1); 1920fbf59bc9STejun Heo goto next_group; 1921fbf59bc9STejun Heo } 1922fbf59bc9STejun Heo } 1923fbf59bc9STejun Heo group_map[cpu] = group; 1924fbf59bc9STejun Heo group_cnt[group]++; 1925fbf59bc9STejun Heo } 1926fbf59bc9STejun Heo 1927fbf59bc9STejun Heo /* 19289c015162SDennis Zhou (Facebook) * Wasted space is caused by a ratio imbalance of upa to group_cnt. 19299c015162SDennis Zhou (Facebook) * Expand the unit_size until we use >= 75% of the units allocated. 19309c015162SDennis Zhou (Facebook) * Related to atom_size, which could be much larger than the unit_size. 1931fbf59bc9STejun Heo */ 1932fbf59bc9STejun Heo last_allocs = INT_MAX; 1933fbf59bc9STejun Heo for (upa = max_upa; upa; upa--) { 1934fbf59bc9STejun Heo int allocs = 0, wasted = 0; 1935fbf59bc9STejun Heo 1936f09f1243SAlexander Kuleshov if (alloc_size % upa || (offset_in_page(alloc_size / upa))) 1937fbf59bc9STejun Heo continue; 1938fbf59bc9STejun Heo 1939fbf59bc9STejun Heo for (group = 0; group < nr_groups; group++) { 1940fbf59bc9STejun Heo int this_allocs = DIV_ROUND_UP(group_cnt[group], upa); 1941fbf59bc9STejun Heo allocs += this_allocs; 1942fbf59bc9STejun Heo wasted += this_allocs * upa - group_cnt[group]; 1943fbf59bc9STejun Heo } 1944fbf59bc9STejun Heo 1945fbf59bc9STejun Heo /* 1946fbf59bc9STejun Heo * Don't accept if wastage is over 1/3. The 1947fbf59bc9STejun Heo * greater-than comparison ensures upa==1 always 1948fbf59bc9STejun Heo * passes the following check. 1949fbf59bc9STejun Heo */ 1950fbf59bc9STejun Heo if (wasted > num_possible_cpus() / 3) 1951fbf59bc9STejun Heo continue; 1952fbf59bc9STejun Heo 1953fbf59bc9STejun Heo /* and then don't consume more memory */ 1954fbf59bc9STejun Heo if (allocs > last_allocs) 1955fbf59bc9STejun Heo break; 1956fbf59bc9STejun Heo last_allocs = allocs; 1957fbf59bc9STejun Heo best_upa = upa; 1958fbf59bc9STejun Heo } 1959fbf59bc9STejun Heo upa = best_upa; 1960fbf59bc9STejun Heo 1961fbf59bc9STejun Heo /* allocate and fill alloc_info */ 1962fbf59bc9STejun Heo for (group = 0; group < nr_groups; group++) 1963fbf59bc9STejun Heo nr_units += roundup(group_cnt[group], upa); 1964fbf59bc9STejun Heo 1965fbf59bc9STejun Heo ai = pcpu_alloc_alloc_info(nr_groups, nr_units); 1966fbf59bc9STejun Heo if (!ai) 1967fbf59bc9STejun Heo return ERR_PTR(-ENOMEM); 1968fbf59bc9STejun Heo cpu_map = ai->groups[0].cpu_map; 1969fbf59bc9STejun Heo 1970fbf59bc9STejun Heo for (group = 0; group < nr_groups; group++) { 1971fbf59bc9STejun Heo ai->groups[group].cpu_map = cpu_map; 1972fbf59bc9STejun Heo cpu_map += roundup(group_cnt[group], upa); 1973fbf59bc9STejun Heo } 1974fbf59bc9STejun Heo 1975fbf59bc9STejun Heo ai->static_size = static_size; 1976fbf59bc9STejun Heo ai->reserved_size = reserved_size; 1977fbf59bc9STejun Heo ai->dyn_size = dyn_size; 1978fbf59bc9STejun Heo ai->unit_size = alloc_size / upa; 1979fbf59bc9STejun Heo ai->atom_size = atom_size; 1980fbf59bc9STejun Heo ai->alloc_size = alloc_size; 1981fbf59bc9STejun Heo 1982fbf59bc9STejun Heo for (group = 0, unit = 0; group_cnt[group]; group++) { 1983fbf59bc9STejun Heo struct pcpu_group_info *gi = &ai->groups[group]; 1984fbf59bc9STejun Heo 1985fbf59bc9STejun Heo /* 1986fbf59bc9STejun Heo * Initialize base_offset as if all groups are located 1987fbf59bc9STejun Heo * back-to-back. The caller should update this to 1988fbf59bc9STejun Heo * reflect actual allocation. 1989fbf59bc9STejun Heo */ 1990fbf59bc9STejun Heo gi->base_offset = unit * ai->unit_size; 1991fbf59bc9STejun Heo 1992fbf59bc9STejun Heo for_each_possible_cpu(cpu) 1993fbf59bc9STejun Heo if (group_map[cpu] == group) 1994fbf59bc9STejun Heo gi->cpu_map[gi->nr_units++] = cpu; 1995fbf59bc9STejun Heo gi->nr_units = roundup(gi->nr_units, upa); 1996fbf59bc9STejun Heo unit += gi->nr_units; 1997fbf59bc9STejun Heo } 1998fbf59bc9STejun Heo BUG_ON(unit != nr_units); 1999fbf59bc9STejun Heo 2000fbf59bc9STejun Heo return ai; 2001fbf59bc9STejun Heo } 20023c9a024fSTejun Heo #endif /* BUILD_EMBED_FIRST_CHUNK || BUILD_PAGE_FIRST_CHUNK */ 2003fbf59bc9STejun Heo 20043c9a024fSTejun Heo #if defined(BUILD_EMBED_FIRST_CHUNK) 200566c3a757STejun Heo /** 200666c3a757STejun Heo * pcpu_embed_first_chunk - embed the first percpu chunk into bootmem 200766c3a757STejun Heo * @reserved_size: the size of reserved percpu area in bytes 20084ba6ce25STejun Heo * @dyn_size: minimum free size for dynamic allocation in bytes 2009c8826dd5STejun Heo * @atom_size: allocation atom size 2010c8826dd5STejun Heo * @cpu_distance_fn: callback to determine distance between cpus, optional 2011c8826dd5STejun Heo * @alloc_fn: function to allocate percpu page 201225985edcSLucas De Marchi * @free_fn: function to free percpu page 201366c3a757STejun Heo * 201466c3a757STejun Heo * This is a helper to ease setting up embedded first percpu chunk and 201566c3a757STejun Heo * can be called where pcpu_setup_first_chunk() is expected. 201666c3a757STejun Heo * 201766c3a757STejun Heo * If this function is used to setup the first chunk, it is allocated 2018c8826dd5STejun Heo * by calling @alloc_fn and used as-is without being mapped into 2019c8826dd5STejun Heo * vmalloc area. Allocations are always whole multiples of @atom_size 2020c8826dd5STejun Heo * aligned to @atom_size. 2021c8826dd5STejun Heo * 2022c8826dd5STejun Heo * This enables the first chunk to piggy back on the linear physical 2023c8826dd5STejun Heo * mapping which often uses larger page size. Please note that this 2024c8826dd5STejun Heo * can result in very sparse cpu->unit mapping on NUMA machines thus 2025c8826dd5STejun Heo * requiring large vmalloc address space. Don't use this allocator if 2026c8826dd5STejun Heo * vmalloc space is not orders of magnitude larger than distances 2027c8826dd5STejun Heo * between node memory addresses (ie. 32bit NUMA machines). 202866c3a757STejun Heo * 20294ba6ce25STejun Heo * @dyn_size specifies the minimum dynamic area size. 203066c3a757STejun Heo * 203166c3a757STejun Heo * If the needed size is smaller than the minimum or specified unit 2032c8826dd5STejun Heo * size, the leftover is returned using @free_fn. 203366c3a757STejun Heo * 203466c3a757STejun Heo * RETURNS: 2035fb435d52STejun Heo * 0 on success, -errno on failure. 203666c3a757STejun Heo */ 20374ba6ce25STejun Heo int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, 2038c8826dd5STejun Heo size_t atom_size, 2039c8826dd5STejun Heo pcpu_fc_cpu_distance_fn_t cpu_distance_fn, 2040c8826dd5STejun Heo pcpu_fc_alloc_fn_t alloc_fn, 2041c8826dd5STejun Heo pcpu_fc_free_fn_t free_fn) 204266c3a757STejun Heo { 2043c8826dd5STejun Heo void *base = (void *)ULONG_MAX; 2044c8826dd5STejun Heo void **areas = NULL; 2045fd1e8a1fSTejun Heo struct pcpu_alloc_info *ai; 204693c76b6bSzijun_hu size_t size_sum, areas_size; 204793c76b6bSzijun_hu unsigned long max_distance; 20489b739662Szijun_hu int group, i, highest_group, rc; 204966c3a757STejun Heo 2050c8826dd5STejun Heo ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size, 2051c8826dd5STejun Heo cpu_distance_fn); 2052fd1e8a1fSTejun Heo if (IS_ERR(ai)) 2053fd1e8a1fSTejun Heo return PTR_ERR(ai); 205466c3a757STejun Heo 2055fd1e8a1fSTejun Heo size_sum = ai->static_size + ai->reserved_size + ai->dyn_size; 2056c8826dd5STejun Heo areas_size = PFN_ALIGN(ai->nr_groups * sizeof(void *)); 205766c3a757STejun Heo 2058999c17e3SSantosh Shilimkar areas = memblock_virt_alloc_nopanic(areas_size, 0); 2059c8826dd5STejun Heo if (!areas) { 2060fb435d52STejun Heo rc = -ENOMEM; 2061c8826dd5STejun Heo goto out_free; 2062fa8a7094STejun Heo } 206366c3a757STejun Heo 20649b739662Szijun_hu /* allocate, copy and determine base address & max_distance */ 20659b739662Szijun_hu highest_group = 0; 2066c8826dd5STejun Heo for (group = 0; group < ai->nr_groups; group++) { 2067c8826dd5STejun Heo struct pcpu_group_info *gi = &ai->groups[group]; 2068c8826dd5STejun Heo unsigned int cpu = NR_CPUS; 2069c8826dd5STejun Heo void *ptr; 207066c3a757STejun Heo 2071c8826dd5STejun Heo for (i = 0; i < gi->nr_units && cpu == NR_CPUS; i++) 2072c8826dd5STejun Heo cpu = gi->cpu_map[i]; 2073c8826dd5STejun Heo BUG_ON(cpu == NR_CPUS); 2074c8826dd5STejun Heo 2075c8826dd5STejun Heo /* allocate space for the whole group */ 2076c8826dd5STejun Heo ptr = alloc_fn(cpu, gi->nr_units * ai->unit_size, atom_size); 2077c8826dd5STejun Heo if (!ptr) { 2078c8826dd5STejun Heo rc = -ENOMEM; 2079c8826dd5STejun Heo goto out_free_areas; 2080c8826dd5STejun Heo } 2081f528f0b8SCatalin Marinas /* kmemleak tracks the percpu allocations separately */ 2082f528f0b8SCatalin Marinas kmemleak_free(ptr); 2083c8826dd5STejun Heo areas[group] = ptr; 2084c8826dd5STejun Heo 2085c8826dd5STejun Heo base = min(ptr, base); 20869b739662Szijun_hu if (ptr > areas[highest_group]) 20879b739662Szijun_hu highest_group = group; 20889b739662Szijun_hu } 20899b739662Szijun_hu max_distance = areas[highest_group] - base; 20909b739662Szijun_hu max_distance += ai->unit_size * ai->groups[highest_group].nr_units; 20919b739662Szijun_hu 20929b739662Szijun_hu /* warn if maximum distance is further than 75% of vmalloc space */ 20939b739662Szijun_hu if (max_distance > VMALLOC_TOTAL * 3 / 4) { 20949b739662Szijun_hu pr_warn("max_distance=0x%lx too large for vmalloc space 0x%lx\n", 20959b739662Szijun_hu max_distance, VMALLOC_TOTAL); 20969b739662Szijun_hu #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK 20979b739662Szijun_hu /* and fail if we have fallback */ 20989b739662Szijun_hu rc = -EINVAL; 20999b739662Szijun_hu goto out_free_areas; 21009b739662Szijun_hu #endif 210142b64281STejun Heo } 210242b64281STejun Heo 210342b64281STejun Heo /* 210442b64281STejun Heo * Copy data and free unused parts. This should happen after all 210542b64281STejun Heo * allocations are complete; otherwise, we may end up with 210642b64281STejun Heo * overlapping groups. 210742b64281STejun Heo */ 210842b64281STejun Heo for (group = 0; group < ai->nr_groups; group++) { 210942b64281STejun Heo struct pcpu_group_info *gi = &ai->groups[group]; 211042b64281STejun Heo void *ptr = areas[group]; 2111c8826dd5STejun Heo 2112c8826dd5STejun Heo for (i = 0; i < gi->nr_units; i++, ptr += ai->unit_size) { 2113c8826dd5STejun Heo if (gi->cpu_map[i] == NR_CPUS) { 2114c8826dd5STejun Heo /* unused unit, free whole */ 2115c8826dd5STejun Heo free_fn(ptr, ai->unit_size); 2116c8826dd5STejun Heo continue; 2117c8826dd5STejun Heo } 2118c8826dd5STejun Heo /* copy and return the unused part */ 2119fd1e8a1fSTejun Heo memcpy(ptr, __per_cpu_load, ai->static_size); 2120c8826dd5STejun Heo free_fn(ptr + size_sum, ai->unit_size - size_sum); 2121c8826dd5STejun Heo } 212266c3a757STejun Heo } 212366c3a757STejun Heo 2124c8826dd5STejun Heo /* base address is now known, determine group base offsets */ 21256ea529a2STejun Heo for (group = 0; group < ai->nr_groups; group++) { 2126c8826dd5STejun Heo ai->groups[group].base_offset = areas[group] - base; 21276ea529a2STejun Heo } 2128c8826dd5STejun Heo 2129870d4b12SJoe Perches pr_info("Embedded %zu pages/cpu @%p s%zu r%zu d%zu u%zu\n", 2130fd1e8a1fSTejun Heo PFN_DOWN(size_sum), base, ai->static_size, ai->reserved_size, 2131fd1e8a1fSTejun Heo ai->dyn_size, ai->unit_size); 213266c3a757STejun Heo 2133fb435d52STejun Heo rc = pcpu_setup_first_chunk(ai, base); 2134c8826dd5STejun Heo goto out_free; 2135c8826dd5STejun Heo 2136c8826dd5STejun Heo out_free_areas: 2137c8826dd5STejun Heo for (group = 0; group < ai->nr_groups; group++) 2138f851c8d8SMichael Holzheu if (areas[group]) 2139c8826dd5STejun Heo free_fn(areas[group], 2140c8826dd5STejun Heo ai->groups[group].nr_units * ai->unit_size); 2141c8826dd5STejun Heo out_free: 2142fd1e8a1fSTejun Heo pcpu_free_alloc_info(ai); 2143c8826dd5STejun Heo if (areas) 2144999c17e3SSantosh Shilimkar memblock_free_early(__pa(areas), areas_size); 2145fb435d52STejun Heo return rc; 2146d4b95f80STejun Heo } 21473c9a024fSTejun Heo #endif /* BUILD_EMBED_FIRST_CHUNK */ 2148d4b95f80STejun Heo 21493c9a024fSTejun Heo #ifdef BUILD_PAGE_FIRST_CHUNK 2150d4b95f80STejun Heo /** 215100ae4064STejun Heo * pcpu_page_first_chunk - map the first chunk using PAGE_SIZE pages 2152d4b95f80STejun Heo * @reserved_size: the size of reserved percpu area in bytes 2153d4b95f80STejun Heo * @alloc_fn: function to allocate percpu page, always called with PAGE_SIZE 215425985edcSLucas De Marchi * @free_fn: function to free percpu page, always called with PAGE_SIZE 2155d4b95f80STejun Heo * @populate_pte_fn: function to populate pte 2156d4b95f80STejun Heo * 215700ae4064STejun Heo * This is a helper to ease setting up page-remapped first percpu 215800ae4064STejun Heo * chunk and can be called where pcpu_setup_first_chunk() is expected. 2159d4b95f80STejun Heo * 2160d4b95f80STejun Heo * This is the basic allocator. Static percpu area is allocated 2161d4b95f80STejun Heo * page-by-page into vmalloc area. 2162d4b95f80STejun Heo * 2163d4b95f80STejun Heo * RETURNS: 2164fb435d52STejun Heo * 0 on success, -errno on failure. 2165d4b95f80STejun Heo */ 2166fb435d52STejun Heo int __init pcpu_page_first_chunk(size_t reserved_size, 2167d4b95f80STejun Heo pcpu_fc_alloc_fn_t alloc_fn, 2168d4b95f80STejun Heo pcpu_fc_free_fn_t free_fn, 2169d4b95f80STejun Heo pcpu_fc_populate_pte_fn_t populate_pte_fn) 2170d4b95f80STejun Heo { 21718f05a6a6STejun Heo static struct vm_struct vm; 2172fd1e8a1fSTejun Heo struct pcpu_alloc_info *ai; 217300ae4064STejun Heo char psize_str[16]; 2174ce3141a2STejun Heo int unit_pages; 2175d4b95f80STejun Heo size_t pages_size; 2176ce3141a2STejun Heo struct page **pages; 2177fb435d52STejun Heo int unit, i, j, rc; 21788f606604Szijun_hu int upa; 21798f606604Szijun_hu int nr_g0_units; 2180d4b95f80STejun Heo 218100ae4064STejun Heo snprintf(psize_str, sizeof(psize_str), "%luK", PAGE_SIZE >> 10); 218200ae4064STejun Heo 21834ba6ce25STejun Heo ai = pcpu_build_alloc_info(reserved_size, 0, PAGE_SIZE, NULL); 2184fd1e8a1fSTejun Heo if (IS_ERR(ai)) 2185fd1e8a1fSTejun Heo return PTR_ERR(ai); 2186fd1e8a1fSTejun Heo BUG_ON(ai->nr_groups != 1); 21878f606604Szijun_hu upa = ai->alloc_size/ai->unit_size; 21888f606604Szijun_hu nr_g0_units = roundup(num_possible_cpus(), upa); 21898f606604Szijun_hu if (unlikely(WARN_ON(ai->groups[0].nr_units != nr_g0_units))) { 21908f606604Szijun_hu pcpu_free_alloc_info(ai); 21918f606604Szijun_hu return -EINVAL; 21928f606604Szijun_hu } 2193fd1e8a1fSTejun Heo 2194fd1e8a1fSTejun Heo unit_pages = ai->unit_size >> PAGE_SHIFT; 2195d4b95f80STejun Heo 2196d4b95f80STejun Heo /* unaligned allocations can't be freed, round up to page size */ 2197fd1e8a1fSTejun Heo pages_size = PFN_ALIGN(unit_pages * num_possible_cpus() * 2198fd1e8a1fSTejun Heo sizeof(pages[0])); 2199999c17e3SSantosh Shilimkar pages = memblock_virt_alloc(pages_size, 0); 2200d4b95f80STejun Heo 22018f05a6a6STejun Heo /* allocate pages */ 2202d4b95f80STejun Heo j = 0; 22038f606604Szijun_hu for (unit = 0; unit < num_possible_cpus(); unit++) { 2204fd1e8a1fSTejun Heo unsigned int cpu = ai->groups[0].cpu_map[unit]; 22058f606604Szijun_hu for (i = 0; i < unit_pages; i++) { 2206d4b95f80STejun Heo void *ptr; 2207d4b95f80STejun Heo 22083cbc8565STejun Heo ptr = alloc_fn(cpu, PAGE_SIZE, PAGE_SIZE); 2209d4b95f80STejun Heo if (!ptr) { 2210870d4b12SJoe Perches pr_warn("failed to allocate %s page for cpu%u\n", 2211598d8091SJoe Perches psize_str, cpu); 2212d4b95f80STejun Heo goto enomem; 2213d4b95f80STejun Heo } 2214f528f0b8SCatalin Marinas /* kmemleak tracks the percpu allocations separately */ 2215f528f0b8SCatalin Marinas kmemleak_free(ptr); 2216ce3141a2STejun Heo pages[j++] = virt_to_page(ptr); 2217d4b95f80STejun Heo } 22188f606604Szijun_hu } 2219d4b95f80STejun Heo 22208f05a6a6STejun Heo /* allocate vm area, map the pages and copy static data */ 22218f05a6a6STejun Heo vm.flags = VM_ALLOC; 2222fd1e8a1fSTejun Heo vm.size = num_possible_cpus() * ai->unit_size; 22238f05a6a6STejun Heo vm_area_register_early(&vm, PAGE_SIZE); 22248f05a6a6STejun Heo 2225fd1e8a1fSTejun Heo for (unit = 0; unit < num_possible_cpus(); unit++) { 22261d9d3257STejun Heo unsigned long unit_addr = 2227fd1e8a1fSTejun Heo (unsigned long)vm.addr + unit * ai->unit_size; 22288f05a6a6STejun Heo 2229ce3141a2STejun Heo for (i = 0; i < unit_pages; i++) 22308f05a6a6STejun Heo populate_pte_fn(unit_addr + (i << PAGE_SHIFT)); 22318f05a6a6STejun Heo 22328f05a6a6STejun Heo /* pte already populated, the following shouldn't fail */ 2233fb435d52STejun Heo rc = __pcpu_map_pages(unit_addr, &pages[unit * unit_pages], 2234ce3141a2STejun Heo unit_pages); 2235fb435d52STejun Heo if (rc < 0) 2236fb435d52STejun Heo panic("failed to map percpu area, err=%d\n", rc); 22378f05a6a6STejun Heo 22388f05a6a6STejun Heo /* 22398f05a6a6STejun Heo * FIXME: Archs with virtual cache should flush local 22408f05a6a6STejun Heo * cache for the linear mapping here - something 22418f05a6a6STejun Heo * equivalent to flush_cache_vmap() on the local cpu. 22428f05a6a6STejun Heo * flush_cache_vmap() can't be used as most supporting 22438f05a6a6STejun Heo * data structures are not set up yet. 22448f05a6a6STejun Heo */ 22458f05a6a6STejun Heo 22468f05a6a6STejun Heo /* copy static data */ 2247fd1e8a1fSTejun Heo memcpy((void *)unit_addr, __per_cpu_load, ai->static_size); 224866c3a757STejun Heo } 224966c3a757STejun Heo 225066c3a757STejun Heo /* we're ready, commit */ 2251870d4b12SJoe Perches pr_info("%d %s pages/cpu @%p s%zu r%zu d%zu\n", 2252fd1e8a1fSTejun Heo unit_pages, psize_str, vm.addr, ai->static_size, 2253fd1e8a1fSTejun Heo ai->reserved_size, ai->dyn_size); 225466c3a757STejun Heo 2255fb435d52STejun Heo rc = pcpu_setup_first_chunk(ai, vm.addr); 2256d4b95f80STejun Heo goto out_free_ar; 2257d4b95f80STejun Heo 2258d4b95f80STejun Heo enomem: 2259d4b95f80STejun Heo while (--j >= 0) 2260ce3141a2STejun Heo free_fn(page_address(pages[j]), PAGE_SIZE); 2261fb435d52STejun Heo rc = -ENOMEM; 2262d4b95f80STejun Heo out_free_ar: 2263999c17e3SSantosh Shilimkar memblock_free_early(__pa(pages), pages_size); 2264fd1e8a1fSTejun Heo pcpu_free_alloc_info(ai); 2265fb435d52STejun Heo return rc; 226666c3a757STejun Heo } 22673c9a024fSTejun Heo #endif /* BUILD_PAGE_FIRST_CHUNK */ 2268d4b95f80STejun Heo 2269bbddff05STejun Heo #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA 22708c4bfc6eSTejun Heo /* 2271bbddff05STejun Heo * Generic SMP percpu area setup. 2272e74e3962STejun Heo * 2273e74e3962STejun Heo * The embedding helper is used because its behavior closely resembles 2274e74e3962STejun Heo * the original non-dynamic generic percpu area setup. This is 2275e74e3962STejun Heo * important because many archs have addressing restrictions and might 2276e74e3962STejun Heo * fail if the percpu area is located far away from the previous 2277e74e3962STejun Heo * location. As an added bonus, in non-NUMA cases, embedding is 2278e74e3962STejun Heo * generally a good idea TLB-wise because percpu area can piggy back 2279e74e3962STejun Heo * on the physical linear memory mapping which uses large page 2280e74e3962STejun Heo * mappings on applicable archs. 2281e74e3962STejun Heo */ 2282e74e3962STejun Heo unsigned long __per_cpu_offset[NR_CPUS] __read_mostly; 2283e74e3962STejun Heo EXPORT_SYMBOL(__per_cpu_offset); 2284e74e3962STejun Heo 2285c8826dd5STejun Heo static void * __init pcpu_dfl_fc_alloc(unsigned int cpu, size_t size, 2286c8826dd5STejun Heo size_t align) 2287c8826dd5STejun Heo { 2288999c17e3SSantosh Shilimkar return memblock_virt_alloc_from_nopanic( 2289999c17e3SSantosh Shilimkar size, align, __pa(MAX_DMA_ADDRESS)); 2290c8826dd5STejun Heo } 2291c8826dd5STejun Heo 2292c8826dd5STejun Heo static void __init pcpu_dfl_fc_free(void *ptr, size_t size) 2293c8826dd5STejun Heo { 2294999c17e3SSantosh Shilimkar memblock_free_early(__pa(ptr), size); 2295c8826dd5STejun Heo } 2296c8826dd5STejun Heo 2297e74e3962STejun Heo void __init setup_per_cpu_areas(void) 2298e74e3962STejun Heo { 2299e74e3962STejun Heo unsigned long delta; 2300e74e3962STejun Heo unsigned int cpu; 2301fb435d52STejun Heo int rc; 2302e74e3962STejun Heo 2303e74e3962STejun Heo /* 2304e74e3962STejun Heo * Always reserve area for module percpu variables. That's 2305e74e3962STejun Heo * what the legacy allocator did. 2306e74e3962STejun Heo */ 2307fb435d52STejun Heo rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, 2308c8826dd5STejun Heo PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, NULL, 2309c8826dd5STejun Heo pcpu_dfl_fc_alloc, pcpu_dfl_fc_free); 2310fb435d52STejun Heo if (rc < 0) 2311bbddff05STejun Heo panic("Failed to initialize percpu areas."); 2312e74e3962STejun Heo 2313e74e3962STejun Heo delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; 2314e74e3962STejun Heo for_each_possible_cpu(cpu) 2315fb435d52STejun Heo __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu]; 2316e74e3962STejun Heo } 2317e74e3962STejun Heo #endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */ 2318099a19d9STejun Heo 2319bbddff05STejun Heo #else /* CONFIG_SMP */ 2320bbddff05STejun Heo 2321bbddff05STejun Heo /* 2322bbddff05STejun Heo * UP percpu area setup. 2323bbddff05STejun Heo * 2324bbddff05STejun Heo * UP always uses km-based percpu allocator with identity mapping. 2325bbddff05STejun Heo * Static percpu variables are indistinguishable from the usual static 2326bbddff05STejun Heo * variables and don't require any special preparation. 2327bbddff05STejun Heo */ 2328bbddff05STejun Heo void __init setup_per_cpu_areas(void) 2329bbddff05STejun Heo { 2330bbddff05STejun Heo const size_t unit_size = 2331bbddff05STejun Heo roundup_pow_of_two(max_t(size_t, PCPU_MIN_UNIT_SIZE, 2332bbddff05STejun Heo PERCPU_DYNAMIC_RESERVE)); 2333bbddff05STejun Heo struct pcpu_alloc_info *ai; 2334bbddff05STejun Heo void *fc; 2335bbddff05STejun Heo 2336bbddff05STejun Heo ai = pcpu_alloc_alloc_info(1, 1); 2337999c17e3SSantosh Shilimkar fc = memblock_virt_alloc_from_nopanic(unit_size, 2338999c17e3SSantosh Shilimkar PAGE_SIZE, 2339999c17e3SSantosh Shilimkar __pa(MAX_DMA_ADDRESS)); 2340bbddff05STejun Heo if (!ai || !fc) 2341bbddff05STejun Heo panic("Failed to allocate memory for percpu areas."); 2342100d13c3SCatalin Marinas /* kmemleak tracks the percpu allocations separately */ 2343100d13c3SCatalin Marinas kmemleak_free(fc); 2344bbddff05STejun Heo 2345bbddff05STejun Heo ai->dyn_size = unit_size; 2346bbddff05STejun Heo ai->unit_size = unit_size; 2347bbddff05STejun Heo ai->atom_size = unit_size; 2348bbddff05STejun Heo ai->alloc_size = unit_size; 2349bbddff05STejun Heo ai->groups[0].nr_units = 1; 2350bbddff05STejun Heo ai->groups[0].cpu_map[0] = 0; 2351bbddff05STejun Heo 2352bbddff05STejun Heo if (pcpu_setup_first_chunk(ai, fc) < 0) 2353bbddff05STejun Heo panic("Failed to initialize percpu areas."); 2354bbddff05STejun Heo } 2355bbddff05STejun Heo 2356bbddff05STejun Heo #endif /* CONFIG_SMP */ 2357bbddff05STejun Heo 2358099a19d9STejun Heo /* 2359099a19d9STejun Heo * First and reserved chunks are initialized with temporary allocation 2360099a19d9STejun Heo * map in initdata so that they can be used before slab is online. 2361099a19d9STejun Heo * This function is called after slab is brought up and replaces those 2362099a19d9STejun Heo * with properly allocated maps. 2363099a19d9STejun Heo */ 2364099a19d9STejun Heo void __init percpu_init_late(void) 2365099a19d9STejun Heo { 2366099a19d9STejun Heo struct pcpu_chunk *target_chunks[] = 2367099a19d9STejun Heo { pcpu_first_chunk, pcpu_reserved_chunk, NULL }; 2368099a19d9STejun Heo struct pcpu_chunk *chunk; 2369099a19d9STejun Heo unsigned long flags; 2370099a19d9STejun Heo int i; 2371099a19d9STejun Heo 2372099a19d9STejun Heo for (i = 0; (chunk = target_chunks[i]); i++) { 2373099a19d9STejun Heo int *map; 2374099a19d9STejun Heo const size_t size = PERCPU_DYNAMIC_EARLY_SLOTS * sizeof(map[0]); 2375099a19d9STejun Heo 2376099a19d9STejun Heo BUILD_BUG_ON(size > PAGE_SIZE); 2377099a19d9STejun Heo 237890459ce0SBob Liu map = pcpu_mem_zalloc(size); 2379099a19d9STejun Heo BUG_ON(!map); 2380099a19d9STejun Heo 2381099a19d9STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 2382099a19d9STejun Heo memcpy(map, chunk->map, size); 2383099a19d9STejun Heo chunk->map = map; 2384099a19d9STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 2385099a19d9STejun Heo } 2386099a19d9STejun Heo } 23871a4d7607STejun Heo 23881a4d7607STejun Heo /* 23891a4d7607STejun Heo * Percpu allocator is initialized early during boot when neither slab or 23901a4d7607STejun Heo * workqueue is available. Plug async management until everything is up 23911a4d7607STejun Heo * and running. 23921a4d7607STejun Heo */ 23931a4d7607STejun Heo static int __init percpu_enable_async(void) 23941a4d7607STejun Heo { 23951a4d7607STejun Heo pcpu_async_enabled = true; 23961a4d7607STejun Heo return 0; 23971a4d7607STejun Heo } 23981a4d7607STejun Heo subsys_initcall(percpu_enable_async); 2399