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 * 7*9c015162SDennis Zhou (Facebook) * This file is released under the GPLv2 license. 8fbf59bc9STejun Heo * 9*9c015162SDennis Zhou (Facebook) * The percpu allocator handles both static and dynamic areas. Percpu 10*9c015162SDennis Zhou (Facebook) * areas are allocated in chunks which are divided into units. There is 11*9c015162SDennis Zhou (Facebook) * a 1-to-1 mapping for units to possible cpus. These units are grouped 12*9c015162SDennis 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 * 19*9c015162SDennis Zhou (Facebook) * Allocation is done by offsets into a unit's address space. Ie., an 20*9c015162SDennis Zhou (Facebook) * area of 512 bytes at 6k in c1 occupies 512 bytes at 6k in c1:u0, 21*9c015162SDennis Zhou (Facebook) * c1:u1, c1:u2, etc. On NUMA machines, the mapping may be non-linear 22*9c015162SDennis Zhou (Facebook) * and even sparse. Access is handled by configuring percpu base 23*9c015162SDennis Zhou (Facebook) * registers according to the cpu to unit mappings and offsetting the 24*9c015162SDennis Zhou (Facebook) * base address using pcpu_unit_size. 25fbf59bc9STejun Heo * 26*9c015162SDennis Zhou (Facebook) * There is special consideration for the first chunk which must handle 27*9c015162SDennis Zhou (Facebook) * the static percpu variables in the kernel image as allocation services 28*9c015162SDennis Zhou (Facebook) * are not online yet. In short, the first chunk is structure like so: 29*9c015162SDennis Zhou (Facebook) * 30*9c015162SDennis Zhou (Facebook) * <Static | [Reserved] | Dynamic> 31*9c015162SDennis Zhou (Facebook) * 32*9c015162SDennis Zhou (Facebook) * The static data is copied from the original section managed by the 33*9c015162SDennis Zhou (Facebook) * linker. The reserved section, if non-zero, primarily manages static 34*9c015162SDennis Zhou (Facebook) * percpu variables from kernel modules. Finally, the dynamic section 35*9c015162SDennis 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 * 45*9c015162SDennis Zhou (Facebook) * These chunks are organized into lists according to free_size and 46*9c015162SDennis Zhou (Facebook) * tries to allocate from the fullest chunk first. Each chunk maintains 47*9c015162SDennis Zhou (Facebook) * a maximum contiguous area size hint which is guaranteed to be equal 48*9c015162SDennis Zhou (Facebook) * to or larger than the maximum contiguous area in the chunk. This 49*9c015162SDennis Zhou (Facebook) * helps prevent the allocator from iterating over chunks unnecessarily. 50*9c015162SDennis 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 148ae9e6bc9STejun Heo * chunk and serves it for reserved allocations. The amount of 149ae9e6bc9STejun Heo * reserved offset is in pcpu_reserved_chunk_limit. When reserved 150ae9e6bc9STejun Heo * area doesn't exist, the following variables contain NULL and 0 151ae9e6bc9STejun Heo * respectively. 152ae9e6bc9STejun Heo */ 1538fa3ed80SDennis Zhou struct pcpu_chunk *pcpu_reserved_chunk __ro_after_init; 1541328710bSDaniel Micay static int pcpu_reserved_chunk_limit __ro_after_init; 155edcb4639STejun Heo 1568fa3ed80SDennis Zhou DEFINE_SPINLOCK(pcpu_lock); /* all internal data structures */ 1576710e594STejun Heo static DEFINE_MUTEX(pcpu_alloc_mutex); /* chunk create/destroy, [de]pop, map ext */ 158fbf59bc9STejun Heo 1598fa3ed80SDennis Zhou struct list_head *pcpu_slot __ro_after_init; /* chunk list slots */ 160fbf59bc9STejun Heo 1614f996e23STejun Heo /* chunks which need their map areas extended, protected by pcpu_lock */ 1624f996e23STejun Heo static LIST_HEAD(pcpu_map_extend_chunks); 1634f996e23STejun Heo 164b539b87fSTejun Heo /* 165b539b87fSTejun Heo * The number of empty populated pages, protected by pcpu_lock. The 166b539b87fSTejun Heo * reserved chunk doesn't contribute to the count. 167b539b87fSTejun Heo */ 1686b9b6f39SDennis Zhou (Facebook) int pcpu_nr_empty_pop_pages; 169b539b87fSTejun Heo 1701a4d7607STejun Heo /* 1711a4d7607STejun Heo * Balance work is used to populate or destroy chunks asynchronously. We 1721a4d7607STejun Heo * try to keep the number of populated free pages between 1731a4d7607STejun Heo * PCPU_EMPTY_POP_PAGES_LOW and HIGH for atomic allocations and at most one 1741a4d7607STejun Heo * empty chunk. 1751a4d7607STejun Heo */ 176fe6bd8c3STejun Heo static void pcpu_balance_workfn(struct work_struct *work); 177fe6bd8c3STejun Heo static DECLARE_WORK(pcpu_balance_work, pcpu_balance_workfn); 1781a4d7607STejun Heo static bool pcpu_async_enabled __read_mostly; 1791a4d7607STejun Heo static bool pcpu_atomic_alloc_failed; 1801a4d7607STejun Heo 1811a4d7607STejun Heo static void pcpu_schedule_balance_work(void) 1821a4d7607STejun Heo { 1831a4d7607STejun Heo if (pcpu_async_enabled) 1841a4d7607STejun Heo schedule_work(&pcpu_balance_work); 1851a4d7607STejun Heo } 186a56dbddfSTejun Heo 187020ec653STejun Heo static bool pcpu_addr_in_first_chunk(void *addr) 188020ec653STejun Heo { 189020ec653STejun Heo void *first_start = pcpu_first_chunk->base_addr; 190020ec653STejun Heo 191020ec653STejun Heo return addr >= first_start && addr < first_start + pcpu_unit_size; 192020ec653STejun Heo } 193020ec653STejun Heo 194020ec653STejun Heo static bool pcpu_addr_in_reserved_chunk(void *addr) 195020ec653STejun Heo { 196020ec653STejun Heo void *first_start = pcpu_first_chunk->base_addr; 197020ec653STejun Heo 198020ec653STejun Heo return addr >= first_start && 199020ec653STejun Heo addr < first_start + pcpu_reserved_chunk_limit; 200020ec653STejun Heo } 201020ec653STejun Heo 202d9b55eebSTejun Heo static int __pcpu_size_to_slot(int size) 203fbf59bc9STejun Heo { 204cae3aeb8STejun Heo int highbit = fls(size); /* size is in bytes */ 205fbf59bc9STejun Heo return max(highbit - PCPU_SLOT_BASE_SHIFT + 2, 1); 206fbf59bc9STejun Heo } 207fbf59bc9STejun Heo 208d9b55eebSTejun Heo static int pcpu_size_to_slot(int size) 209d9b55eebSTejun Heo { 210d9b55eebSTejun Heo if (size == pcpu_unit_size) 211d9b55eebSTejun Heo return pcpu_nr_slots - 1; 212d9b55eebSTejun Heo return __pcpu_size_to_slot(size); 213d9b55eebSTejun Heo } 214d9b55eebSTejun Heo 215fbf59bc9STejun Heo static int pcpu_chunk_slot(const struct pcpu_chunk *chunk) 216fbf59bc9STejun Heo { 217fbf59bc9STejun Heo if (chunk->free_size < sizeof(int) || chunk->contig_hint < sizeof(int)) 218fbf59bc9STejun Heo return 0; 219fbf59bc9STejun Heo 220fbf59bc9STejun Heo return pcpu_size_to_slot(chunk->free_size); 221fbf59bc9STejun Heo } 222fbf59bc9STejun Heo 22388999a89STejun Heo /* set the pointer to a chunk in a page struct */ 22488999a89STejun Heo static void pcpu_set_page_chunk(struct page *page, struct pcpu_chunk *pcpu) 22588999a89STejun Heo { 22688999a89STejun Heo page->index = (unsigned long)pcpu; 22788999a89STejun Heo } 22888999a89STejun Heo 22988999a89STejun Heo /* obtain pointer to a chunk from a page struct */ 23088999a89STejun Heo static struct pcpu_chunk *pcpu_get_page_chunk(struct page *page) 23188999a89STejun Heo { 23288999a89STejun Heo return (struct pcpu_chunk *)page->index; 23388999a89STejun Heo } 23488999a89STejun Heo 23588999a89STejun Heo static int __maybe_unused pcpu_page_idx(unsigned int cpu, int page_idx) 236fbf59bc9STejun Heo { 2372f39e637STejun Heo return pcpu_unit_map[cpu] * pcpu_unit_pages + page_idx; 238fbf59bc9STejun Heo } 239fbf59bc9STejun Heo 2409983b6f0STejun Heo static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk, 241fbf59bc9STejun Heo unsigned int cpu, int page_idx) 242fbf59bc9STejun Heo { 243bba174f5STejun Heo return (unsigned long)chunk->base_addr + pcpu_unit_offsets[cpu] + 244fb435d52STejun Heo (page_idx << PAGE_SHIFT); 245fbf59bc9STejun Heo } 246fbf59bc9STejun Heo 24788999a89STejun Heo static void __maybe_unused pcpu_next_unpop(struct pcpu_chunk *chunk, 24888999a89STejun Heo int *rs, int *re, int end) 249ce3141a2STejun Heo { 250ce3141a2STejun Heo *rs = find_next_zero_bit(chunk->populated, end, *rs); 251ce3141a2STejun Heo *re = find_next_bit(chunk->populated, end, *rs + 1); 252ce3141a2STejun Heo } 253ce3141a2STejun Heo 25488999a89STejun Heo static void __maybe_unused pcpu_next_pop(struct pcpu_chunk *chunk, 25588999a89STejun Heo int *rs, int *re, int end) 256ce3141a2STejun Heo { 257ce3141a2STejun Heo *rs = find_next_bit(chunk->populated, end, *rs); 258ce3141a2STejun Heo *re = find_next_zero_bit(chunk->populated, end, *rs + 1); 259ce3141a2STejun Heo } 260ce3141a2STejun Heo 261ce3141a2STejun Heo /* 262ce3141a2STejun Heo * (Un)populated page region iterators. Iterate over (un)populated 263b595076aSUwe Kleine-König * page regions between @start and @end in @chunk. @rs and @re should 264ce3141a2STejun Heo * be integer variables and will be set to start and end page index of 265ce3141a2STejun Heo * the current region. 266ce3141a2STejun Heo */ 267ce3141a2STejun Heo #define pcpu_for_each_unpop_region(chunk, rs, re, start, end) \ 268ce3141a2STejun Heo for ((rs) = (start), pcpu_next_unpop((chunk), &(rs), &(re), (end)); \ 269ce3141a2STejun Heo (rs) < (re); \ 270ce3141a2STejun Heo (rs) = (re) + 1, pcpu_next_unpop((chunk), &(rs), &(re), (end))) 271ce3141a2STejun Heo 272ce3141a2STejun Heo #define pcpu_for_each_pop_region(chunk, rs, re, start, end) \ 273ce3141a2STejun Heo for ((rs) = (start), pcpu_next_pop((chunk), &(rs), &(re), (end)); \ 274ce3141a2STejun Heo (rs) < (re); \ 275ce3141a2STejun Heo (rs) = (re) + 1, pcpu_next_pop((chunk), &(rs), &(re), (end))) 276ce3141a2STejun Heo 277fbf59bc9STejun Heo /** 27890459ce0SBob Liu * pcpu_mem_zalloc - allocate memory 2791880d93bSTejun Heo * @size: bytes to allocate 280fbf59bc9STejun Heo * 2811880d93bSTejun Heo * Allocate @size bytes. If @size is smaller than PAGE_SIZE, 28290459ce0SBob Liu * kzalloc() is used; otherwise, vzalloc() is used. The returned 2831880d93bSTejun Heo * memory is always zeroed. 284fbf59bc9STejun Heo * 285ccea34b5STejun Heo * CONTEXT: 286ccea34b5STejun Heo * Does GFP_KERNEL allocation. 287ccea34b5STejun Heo * 288fbf59bc9STejun Heo * RETURNS: 2891880d93bSTejun Heo * Pointer to the allocated area on success, NULL on failure. 290fbf59bc9STejun Heo */ 29190459ce0SBob Liu static void *pcpu_mem_zalloc(size_t size) 292fbf59bc9STejun Heo { 293099a19d9STejun Heo if (WARN_ON_ONCE(!slab_is_available())) 294099a19d9STejun Heo return NULL; 295099a19d9STejun Heo 296fbf59bc9STejun Heo if (size <= PAGE_SIZE) 2971880d93bSTejun Heo return kzalloc(size, GFP_KERNEL); 2987af4c093SJesper Juhl else 2997af4c093SJesper Juhl return vzalloc(size); 3001880d93bSTejun Heo } 301fbf59bc9STejun Heo 3021880d93bSTejun Heo /** 3031880d93bSTejun Heo * pcpu_mem_free - free memory 3041880d93bSTejun Heo * @ptr: memory to free 3051880d93bSTejun Heo * 30690459ce0SBob Liu * Free @ptr. @ptr should have been allocated using pcpu_mem_zalloc(). 3071880d93bSTejun Heo */ 3081d5cfdb0STetsuo Handa static void pcpu_mem_free(void *ptr) 3091880d93bSTejun Heo { 3101d5cfdb0STetsuo Handa kvfree(ptr); 311fbf59bc9STejun Heo } 312fbf59bc9STejun Heo 313fbf59bc9STejun Heo /** 314b539b87fSTejun Heo * pcpu_count_occupied_pages - count the number of pages an area occupies 315b539b87fSTejun Heo * @chunk: chunk of interest 316b539b87fSTejun Heo * @i: index of the area in question 317b539b87fSTejun Heo * 318b539b87fSTejun Heo * Count the number of pages chunk's @i'th area occupies. When the area's 319b539b87fSTejun Heo * start and/or end address isn't aligned to page boundary, the straddled 320b539b87fSTejun Heo * page is included in the count iff the rest of the page is free. 321b539b87fSTejun Heo */ 322b539b87fSTejun Heo static int pcpu_count_occupied_pages(struct pcpu_chunk *chunk, int i) 323b539b87fSTejun Heo { 324b539b87fSTejun Heo int off = chunk->map[i] & ~1; 325b539b87fSTejun Heo int end = chunk->map[i + 1] & ~1; 326b539b87fSTejun Heo 327b539b87fSTejun Heo if (!PAGE_ALIGNED(off) && i > 0) { 328b539b87fSTejun Heo int prev = chunk->map[i - 1]; 329b539b87fSTejun Heo 330b539b87fSTejun Heo if (!(prev & 1) && prev <= round_down(off, PAGE_SIZE)) 331b539b87fSTejun Heo off = round_down(off, PAGE_SIZE); 332b539b87fSTejun Heo } 333b539b87fSTejun Heo 334b539b87fSTejun Heo if (!PAGE_ALIGNED(end) && i + 1 < chunk->map_used) { 335b539b87fSTejun Heo int next = chunk->map[i + 1]; 336b539b87fSTejun Heo int nend = chunk->map[i + 2] & ~1; 337b539b87fSTejun Heo 338b539b87fSTejun Heo if (!(next & 1) && nend >= round_up(end, PAGE_SIZE)) 339b539b87fSTejun Heo end = round_up(end, PAGE_SIZE); 340b539b87fSTejun Heo } 341b539b87fSTejun Heo 342b539b87fSTejun Heo return max_t(int, PFN_DOWN(end) - PFN_UP(off), 0); 343b539b87fSTejun Heo } 344b539b87fSTejun Heo 345b539b87fSTejun Heo /** 346fbf59bc9STejun Heo * pcpu_chunk_relocate - put chunk in the appropriate chunk slot 347fbf59bc9STejun Heo * @chunk: chunk of interest 348fbf59bc9STejun Heo * @oslot: the previous slot it was on 349fbf59bc9STejun Heo * 350fbf59bc9STejun Heo * This function is called after an allocation or free changed @chunk. 351fbf59bc9STejun Heo * New slot according to the changed state is determined and @chunk is 352edcb4639STejun Heo * moved to the slot. Note that the reserved chunk is never put on 353edcb4639STejun Heo * chunk slots. 354ccea34b5STejun Heo * 355ccea34b5STejun Heo * CONTEXT: 356ccea34b5STejun Heo * pcpu_lock. 357fbf59bc9STejun Heo */ 358fbf59bc9STejun Heo static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot) 359fbf59bc9STejun Heo { 360fbf59bc9STejun Heo int nslot = pcpu_chunk_slot(chunk); 361fbf59bc9STejun Heo 362edcb4639STejun Heo if (chunk != pcpu_reserved_chunk && oslot != nslot) { 363fbf59bc9STejun Heo if (oslot < nslot) 364fbf59bc9STejun Heo list_move(&chunk->list, &pcpu_slot[nslot]); 365fbf59bc9STejun Heo else 366fbf59bc9STejun Heo list_move_tail(&chunk->list, &pcpu_slot[nslot]); 367fbf59bc9STejun Heo } 368fbf59bc9STejun Heo } 369fbf59bc9STejun Heo 370fbf59bc9STejun Heo /** 371833af842STejun Heo * pcpu_need_to_extend - determine whether chunk area map needs to be extended 372833af842STejun Heo * @chunk: chunk of interest 3739c824b6aSTejun Heo * @is_atomic: the allocation context 3749f7dcf22STejun Heo * 3759c824b6aSTejun Heo * Determine whether area map of @chunk needs to be extended. If 3769c824b6aSTejun Heo * @is_atomic, only the amount necessary for a new allocation is 3779c824b6aSTejun Heo * considered; however, async extension is scheduled if the left amount is 3789c824b6aSTejun Heo * low. If !@is_atomic, it aims for more empty space. Combined, this 3799c824b6aSTejun Heo * ensures that the map is likely to have enough available space to 3809c824b6aSTejun Heo * accomodate atomic allocations which can't extend maps directly. 3819f7dcf22STejun Heo * 382ccea34b5STejun Heo * CONTEXT: 383833af842STejun Heo * pcpu_lock. 384ccea34b5STejun Heo * 3859f7dcf22STejun Heo * RETURNS: 386833af842STejun Heo * New target map allocation length if extension is necessary, 0 387833af842STejun Heo * otherwise. 3889f7dcf22STejun Heo */ 3899c824b6aSTejun Heo static int pcpu_need_to_extend(struct pcpu_chunk *chunk, bool is_atomic) 3909f7dcf22STejun Heo { 3919c824b6aSTejun Heo int margin, new_alloc; 3929f7dcf22STejun Heo 3934f996e23STejun Heo lockdep_assert_held(&pcpu_lock); 3944f996e23STejun Heo 3959c824b6aSTejun Heo if (is_atomic) { 3969c824b6aSTejun Heo margin = 3; 3979c824b6aSTejun Heo 3989c824b6aSTejun Heo if (chunk->map_alloc < 3994f996e23STejun Heo chunk->map_used + PCPU_ATOMIC_MAP_MARGIN_LOW) { 4004f996e23STejun Heo if (list_empty(&chunk->map_extend_list)) { 4014f996e23STejun Heo list_add_tail(&chunk->map_extend_list, 4024f996e23STejun Heo &pcpu_map_extend_chunks); 4034f996e23STejun Heo pcpu_schedule_balance_work(); 4044f996e23STejun Heo } 4054f996e23STejun Heo } 4069c824b6aSTejun Heo } else { 4079c824b6aSTejun Heo margin = PCPU_ATOMIC_MAP_MARGIN_HIGH; 4089c824b6aSTejun Heo } 4099c824b6aSTejun Heo 4109c824b6aSTejun Heo if (chunk->map_alloc >= chunk->map_used + margin) 4119f7dcf22STejun Heo return 0; 4129f7dcf22STejun Heo 4139f7dcf22STejun Heo new_alloc = PCPU_DFL_MAP_ALLOC; 4149c824b6aSTejun Heo while (new_alloc < chunk->map_used + margin) 4159f7dcf22STejun Heo new_alloc *= 2; 4169f7dcf22STejun Heo 417833af842STejun Heo return new_alloc; 418ccea34b5STejun Heo } 419ccea34b5STejun Heo 420833af842STejun Heo /** 421833af842STejun Heo * pcpu_extend_area_map - extend area map of a chunk 422833af842STejun Heo * @chunk: chunk of interest 423833af842STejun Heo * @new_alloc: new target allocation length of the area map 424833af842STejun Heo * 425833af842STejun Heo * Extend area map of @chunk to have @new_alloc entries. 426833af842STejun Heo * 427833af842STejun Heo * CONTEXT: 428833af842STejun Heo * Does GFP_KERNEL allocation. Grabs and releases pcpu_lock. 429833af842STejun Heo * 430833af842STejun Heo * RETURNS: 431833af842STejun Heo * 0 on success, -errno on failure. 432ccea34b5STejun Heo */ 433833af842STejun Heo static int pcpu_extend_area_map(struct pcpu_chunk *chunk, int new_alloc) 434833af842STejun Heo { 435833af842STejun Heo int *old = NULL, *new = NULL; 436833af842STejun Heo size_t old_size = 0, new_size = new_alloc * sizeof(new[0]); 437833af842STejun Heo unsigned long flags; 4389f7dcf22STejun Heo 4396710e594STejun Heo lockdep_assert_held(&pcpu_alloc_mutex); 4406710e594STejun Heo 44190459ce0SBob Liu new = pcpu_mem_zalloc(new_size); 442833af842STejun Heo if (!new) 443833af842STejun Heo return -ENOMEM; 444833af842STejun Heo 445833af842STejun Heo /* acquire pcpu_lock and switch to new area map */ 446833af842STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 447833af842STejun Heo 448833af842STejun Heo if (new_alloc <= chunk->map_alloc) 449833af842STejun Heo goto out_unlock; 450833af842STejun Heo 451833af842STejun Heo old_size = chunk->map_alloc * sizeof(chunk->map[0]); 452a002d148SHuang Shijie old = chunk->map; 453a002d148SHuang Shijie 454a002d148SHuang Shijie memcpy(new, old, old_size); 4559f7dcf22STejun Heo 4569f7dcf22STejun Heo chunk->map_alloc = new_alloc; 4579f7dcf22STejun Heo chunk->map = new; 458833af842STejun Heo new = NULL; 459833af842STejun Heo 460833af842STejun Heo out_unlock: 461833af842STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 462833af842STejun Heo 463833af842STejun Heo /* 464833af842STejun Heo * pcpu_mem_free() might end up calling vfree() which uses 465833af842STejun Heo * IRQ-unsafe lock and thus can't be called under pcpu_lock. 466833af842STejun Heo */ 4671d5cfdb0STetsuo Handa pcpu_mem_free(old); 4681d5cfdb0STetsuo Handa pcpu_mem_free(new); 469833af842STejun Heo 4709f7dcf22STejun Heo return 0; 4719f7dcf22STejun Heo } 4729f7dcf22STejun Heo 4739f7dcf22STejun Heo /** 474a16037c8STejun Heo * pcpu_fit_in_area - try to fit the requested allocation in a candidate area 475a16037c8STejun Heo * @chunk: chunk the candidate area belongs to 476a16037c8STejun Heo * @off: the offset to the start of the candidate area 477a16037c8STejun Heo * @this_size: the size of the candidate area 478a16037c8STejun Heo * @size: the size of the target allocation 479a16037c8STejun Heo * @align: the alignment of the target allocation 480a16037c8STejun Heo * @pop_only: only allocate from already populated region 481a16037c8STejun Heo * 482a16037c8STejun Heo * We're trying to allocate @size bytes aligned at @align. @chunk's area 483a16037c8STejun Heo * at @off sized @this_size is a candidate. This function determines 484a16037c8STejun Heo * whether the target allocation fits in the candidate area and returns the 485a16037c8STejun Heo * number of bytes to pad after @off. If the target area doesn't fit, -1 486a16037c8STejun Heo * is returned. 487a16037c8STejun Heo * 488a16037c8STejun Heo * If @pop_only is %true, this function only considers the already 489a16037c8STejun Heo * populated part of the candidate area. 490a16037c8STejun Heo */ 491a16037c8STejun Heo static int pcpu_fit_in_area(struct pcpu_chunk *chunk, int off, int this_size, 492a16037c8STejun Heo int size, int align, bool pop_only) 493a16037c8STejun Heo { 494a16037c8STejun Heo int cand_off = off; 495a16037c8STejun Heo 496a16037c8STejun Heo while (true) { 497a16037c8STejun Heo int head = ALIGN(cand_off, align) - off; 498a16037c8STejun Heo int page_start, page_end, rs, re; 499a16037c8STejun Heo 500a16037c8STejun Heo if (this_size < head + size) 501a16037c8STejun Heo return -1; 502a16037c8STejun Heo 503a16037c8STejun Heo if (!pop_only) 504a16037c8STejun Heo return head; 505a16037c8STejun Heo 506a16037c8STejun Heo /* 507a16037c8STejun Heo * If the first unpopulated page is beyond the end of the 508a16037c8STejun Heo * allocation, the whole allocation is populated; 509a16037c8STejun Heo * otherwise, retry from the end of the unpopulated area. 510a16037c8STejun Heo */ 511a16037c8STejun Heo page_start = PFN_DOWN(head + off); 512a16037c8STejun Heo page_end = PFN_UP(head + off + size); 513a16037c8STejun Heo 514a16037c8STejun Heo rs = page_start; 515a16037c8STejun Heo pcpu_next_unpop(chunk, &rs, &re, PFN_UP(off + this_size)); 516a16037c8STejun Heo if (rs >= page_end) 517a16037c8STejun Heo return head; 518a16037c8STejun Heo cand_off = re * PAGE_SIZE; 519a16037c8STejun Heo } 520a16037c8STejun Heo } 521a16037c8STejun Heo 522a16037c8STejun Heo /** 523fbf59bc9STejun Heo * pcpu_alloc_area - allocate area from a pcpu_chunk 524fbf59bc9STejun Heo * @chunk: chunk of interest 525cae3aeb8STejun Heo * @size: wanted size in bytes 526fbf59bc9STejun Heo * @align: wanted align 527a16037c8STejun Heo * @pop_only: allocate only from the populated area 528b539b87fSTejun Heo * @occ_pages_p: out param for the number of pages the area occupies 529fbf59bc9STejun Heo * 530fbf59bc9STejun Heo * Try to allocate @size bytes area aligned at @align from @chunk. 531fbf59bc9STejun Heo * Note that this function only allocates the offset. It doesn't 532fbf59bc9STejun Heo * populate or map the area. 533fbf59bc9STejun Heo * 5349f7dcf22STejun Heo * @chunk->map must have at least two free slots. 5359f7dcf22STejun Heo * 536ccea34b5STejun Heo * CONTEXT: 537ccea34b5STejun Heo * pcpu_lock. 538ccea34b5STejun Heo * 539fbf59bc9STejun Heo * RETURNS: 5409f7dcf22STejun Heo * Allocated offset in @chunk on success, -1 if no matching area is 5419f7dcf22STejun Heo * found. 542fbf59bc9STejun Heo */ 543a16037c8STejun Heo static int pcpu_alloc_area(struct pcpu_chunk *chunk, int size, int align, 544b539b87fSTejun Heo bool pop_only, int *occ_pages_p) 545fbf59bc9STejun Heo { 546fbf59bc9STejun Heo int oslot = pcpu_chunk_slot(chunk); 547fbf59bc9STejun Heo int max_contig = 0; 548fbf59bc9STejun Heo int i, off; 5493d331ad7SAl Viro bool seen_free = false; 550723ad1d9SAl Viro int *p; 551fbf59bc9STejun Heo 5523d331ad7SAl Viro for (i = chunk->first_free, p = chunk->map + i; i < chunk->map_used; i++, p++) { 553fbf59bc9STejun Heo int head, tail; 554723ad1d9SAl Viro int this_size; 555723ad1d9SAl Viro 556723ad1d9SAl Viro off = *p; 557723ad1d9SAl Viro if (off & 1) 558723ad1d9SAl Viro continue; 559fbf59bc9STejun Heo 560723ad1d9SAl Viro this_size = (p[1] & ~1) - off; 561a16037c8STejun Heo 562a16037c8STejun Heo head = pcpu_fit_in_area(chunk, off, this_size, size, align, 563a16037c8STejun Heo pop_only); 564a16037c8STejun Heo if (head < 0) { 5653d331ad7SAl Viro if (!seen_free) { 5663d331ad7SAl Viro chunk->first_free = i; 5673d331ad7SAl Viro seen_free = true; 5683d331ad7SAl Viro } 569723ad1d9SAl Viro max_contig = max(this_size, max_contig); 570fbf59bc9STejun Heo continue; 571fbf59bc9STejun Heo } 572fbf59bc9STejun Heo 573fbf59bc9STejun Heo /* 574fbf59bc9STejun Heo * If head is small or the previous block is free, 575fbf59bc9STejun Heo * merge'em. Note that 'small' is defined as smaller 576fbf59bc9STejun Heo * than sizeof(int), which is very small but isn't too 577fbf59bc9STejun Heo * uncommon for percpu allocations. 578fbf59bc9STejun Heo */ 579723ad1d9SAl Viro if (head && (head < sizeof(int) || !(p[-1] & 1))) { 58021ddfd38SJianyu Zhan *p = off += head; 581723ad1d9SAl Viro if (p[-1] & 1) 582fbf59bc9STejun Heo chunk->free_size -= head; 58321ddfd38SJianyu Zhan else 58421ddfd38SJianyu Zhan max_contig = max(*p - p[-1], max_contig); 585723ad1d9SAl Viro this_size -= head; 586fbf59bc9STejun Heo head = 0; 587fbf59bc9STejun Heo } 588fbf59bc9STejun Heo 589fbf59bc9STejun Heo /* if tail is small, just keep it around */ 590723ad1d9SAl Viro tail = this_size - head - size; 591723ad1d9SAl Viro if (tail < sizeof(int)) { 592fbf59bc9STejun Heo tail = 0; 593723ad1d9SAl Viro size = this_size - head; 594723ad1d9SAl Viro } 595fbf59bc9STejun Heo 596fbf59bc9STejun Heo /* split if warranted */ 597fbf59bc9STejun Heo if (head || tail) { 598706c16f2SAl Viro int nr_extra = !!head + !!tail; 599706c16f2SAl Viro 600706c16f2SAl Viro /* insert new subblocks */ 601723ad1d9SAl Viro memmove(p + nr_extra + 1, p + 1, 602706c16f2SAl Viro sizeof(chunk->map[0]) * (chunk->map_used - i)); 603706c16f2SAl Viro chunk->map_used += nr_extra; 604706c16f2SAl Viro 605fbf59bc9STejun Heo if (head) { 6063d331ad7SAl Viro if (!seen_free) { 6073d331ad7SAl Viro chunk->first_free = i; 6083d331ad7SAl Viro seen_free = true; 6093d331ad7SAl Viro } 610723ad1d9SAl Viro *++p = off += head; 611723ad1d9SAl Viro ++i; 612706c16f2SAl Viro max_contig = max(head, max_contig); 613fbf59bc9STejun Heo } 614706c16f2SAl Viro if (tail) { 615723ad1d9SAl Viro p[1] = off + size; 616706c16f2SAl Viro max_contig = max(tail, max_contig); 617706c16f2SAl Viro } 618fbf59bc9STejun Heo } 619fbf59bc9STejun Heo 6203d331ad7SAl Viro if (!seen_free) 6213d331ad7SAl Viro chunk->first_free = i + 1; 6223d331ad7SAl Viro 623fbf59bc9STejun Heo /* update hint and mark allocated */ 624723ad1d9SAl Viro if (i + 1 == chunk->map_used) 625fbf59bc9STejun Heo chunk->contig_hint = max_contig; /* fully scanned */ 626fbf59bc9STejun Heo else 627fbf59bc9STejun Heo chunk->contig_hint = max(chunk->contig_hint, 628fbf59bc9STejun Heo max_contig); 629fbf59bc9STejun Heo 630723ad1d9SAl Viro chunk->free_size -= size; 631723ad1d9SAl Viro *p |= 1; 632fbf59bc9STejun Heo 633b539b87fSTejun Heo *occ_pages_p = pcpu_count_occupied_pages(chunk, i); 634fbf59bc9STejun Heo pcpu_chunk_relocate(chunk, oslot); 635fbf59bc9STejun Heo return off; 636fbf59bc9STejun Heo } 637fbf59bc9STejun Heo 638fbf59bc9STejun Heo chunk->contig_hint = max_contig; /* fully scanned */ 639fbf59bc9STejun Heo pcpu_chunk_relocate(chunk, oslot); 640fbf59bc9STejun Heo 6419f7dcf22STejun Heo /* tell the upper layer that this chunk has no matching area */ 6429f7dcf22STejun Heo return -1; 643fbf59bc9STejun Heo } 644fbf59bc9STejun Heo 645fbf59bc9STejun Heo /** 646fbf59bc9STejun Heo * pcpu_free_area - free area to a pcpu_chunk 647fbf59bc9STejun Heo * @chunk: chunk of interest 648fbf59bc9STejun Heo * @freeme: offset of area to free 649b539b87fSTejun Heo * @occ_pages_p: out param for the number of pages the area occupies 650fbf59bc9STejun Heo * 651fbf59bc9STejun Heo * Free area starting from @freeme to @chunk. Note that this function 652fbf59bc9STejun Heo * only modifies the allocation map. It doesn't depopulate or unmap 653fbf59bc9STejun Heo * the area. 654ccea34b5STejun Heo * 655ccea34b5STejun Heo * CONTEXT: 656ccea34b5STejun Heo * pcpu_lock. 657fbf59bc9STejun Heo */ 658b539b87fSTejun Heo static void pcpu_free_area(struct pcpu_chunk *chunk, int freeme, 659b539b87fSTejun Heo int *occ_pages_p) 660fbf59bc9STejun Heo { 661fbf59bc9STejun Heo int oslot = pcpu_chunk_slot(chunk); 662723ad1d9SAl Viro int off = 0; 663723ad1d9SAl Viro unsigned i, j; 664723ad1d9SAl Viro int to_free = 0; 665723ad1d9SAl Viro int *p; 666fbf59bc9STejun Heo 6675ccd30e4SDennis Zhou lockdep_assert_held(&pcpu_lock); 66830a5b536SDennis Zhou pcpu_stats_area_dealloc(chunk); 6695ccd30e4SDennis Zhou 670723ad1d9SAl Viro freeme |= 1; /* we are searching for <given offset, in use> pair */ 671723ad1d9SAl Viro 672723ad1d9SAl Viro i = 0; 673723ad1d9SAl Viro j = chunk->map_used; 674723ad1d9SAl Viro while (i != j) { 675723ad1d9SAl Viro unsigned k = (i + j) / 2; 676723ad1d9SAl Viro off = chunk->map[k]; 677723ad1d9SAl Viro if (off < freeme) 678723ad1d9SAl Viro i = k + 1; 679723ad1d9SAl Viro else if (off > freeme) 680723ad1d9SAl Viro j = k; 681723ad1d9SAl Viro else 682723ad1d9SAl Viro i = j = k; 683723ad1d9SAl Viro } 684fbf59bc9STejun Heo BUG_ON(off != freeme); 685fbf59bc9STejun Heo 6863d331ad7SAl Viro if (i < chunk->first_free) 6873d331ad7SAl Viro chunk->first_free = i; 6883d331ad7SAl Viro 689723ad1d9SAl Viro p = chunk->map + i; 690723ad1d9SAl Viro *p = off &= ~1; 691723ad1d9SAl Viro chunk->free_size += (p[1] & ~1) - off; 692fbf59bc9STejun Heo 693b539b87fSTejun Heo *occ_pages_p = pcpu_count_occupied_pages(chunk, i); 694b539b87fSTejun Heo 695fbf59bc9STejun Heo /* merge with next? */ 696723ad1d9SAl Viro if (!(p[1] & 1)) 697723ad1d9SAl Viro to_free++; 698723ad1d9SAl Viro /* merge with previous? */ 699723ad1d9SAl Viro if (i > 0 && !(p[-1] & 1)) { 700723ad1d9SAl Viro to_free++; 701723ad1d9SAl Viro i--; 702723ad1d9SAl Viro p--; 703723ad1d9SAl Viro } 704723ad1d9SAl Viro if (to_free) { 705723ad1d9SAl Viro chunk->map_used -= to_free; 706723ad1d9SAl Viro memmove(p + 1, p + 1 + to_free, 707723ad1d9SAl Viro (chunk->map_used - i) * sizeof(chunk->map[0])); 708fbf59bc9STejun Heo } 709fbf59bc9STejun Heo 710723ad1d9SAl Viro chunk->contig_hint = max(chunk->map[i + 1] - chunk->map[i] - 1, chunk->contig_hint); 711fbf59bc9STejun Heo pcpu_chunk_relocate(chunk, oslot); 712fbf59bc9STejun Heo } 713fbf59bc9STejun Heo 7146081089fSTejun Heo static struct pcpu_chunk *pcpu_alloc_chunk(void) 7156081089fSTejun Heo { 7166081089fSTejun Heo struct pcpu_chunk *chunk; 7176081089fSTejun Heo 71890459ce0SBob Liu chunk = pcpu_mem_zalloc(pcpu_chunk_struct_size); 7196081089fSTejun Heo if (!chunk) 7206081089fSTejun Heo return NULL; 7216081089fSTejun Heo 72290459ce0SBob Liu chunk->map = pcpu_mem_zalloc(PCPU_DFL_MAP_ALLOC * 72390459ce0SBob Liu sizeof(chunk->map[0])); 7246081089fSTejun Heo if (!chunk->map) { 7251d5cfdb0STetsuo Handa pcpu_mem_free(chunk); 7266081089fSTejun Heo return NULL; 7276081089fSTejun Heo } 7286081089fSTejun Heo 7296081089fSTejun Heo chunk->map_alloc = PCPU_DFL_MAP_ALLOC; 730723ad1d9SAl Viro chunk->map[0] = 0; 731723ad1d9SAl Viro chunk->map[1] = pcpu_unit_size | 1; 732723ad1d9SAl Viro chunk->map_used = 1; 73330a5b536SDennis Zhou chunk->has_reserved = false; 7346081089fSTejun Heo 7356081089fSTejun Heo INIT_LIST_HEAD(&chunk->list); 7364f996e23STejun Heo INIT_LIST_HEAD(&chunk->map_extend_list); 7376081089fSTejun Heo chunk->free_size = pcpu_unit_size; 7386081089fSTejun Heo chunk->contig_hint = pcpu_unit_size; 7396081089fSTejun Heo 7406081089fSTejun Heo return chunk; 7416081089fSTejun Heo } 7426081089fSTejun Heo 7436081089fSTejun Heo static void pcpu_free_chunk(struct pcpu_chunk *chunk) 7446081089fSTejun Heo { 7456081089fSTejun Heo if (!chunk) 7466081089fSTejun Heo return; 7471d5cfdb0STetsuo Handa pcpu_mem_free(chunk->map); 7481d5cfdb0STetsuo Handa pcpu_mem_free(chunk); 7496081089fSTejun Heo } 7506081089fSTejun Heo 751b539b87fSTejun Heo /** 752b539b87fSTejun Heo * pcpu_chunk_populated - post-population bookkeeping 753b539b87fSTejun Heo * @chunk: pcpu_chunk which got populated 754b539b87fSTejun Heo * @page_start: the start page 755b539b87fSTejun Heo * @page_end: the end page 756b539b87fSTejun Heo * 757b539b87fSTejun Heo * Pages in [@page_start,@page_end) have been populated to @chunk. Update 758b539b87fSTejun Heo * the bookkeeping information accordingly. Must be called after each 759b539b87fSTejun Heo * successful population. 760b539b87fSTejun Heo */ 761b539b87fSTejun Heo static void pcpu_chunk_populated(struct pcpu_chunk *chunk, 762b539b87fSTejun Heo int page_start, int page_end) 763b539b87fSTejun Heo { 764b539b87fSTejun Heo int nr = page_end - page_start; 765b539b87fSTejun Heo 766b539b87fSTejun Heo lockdep_assert_held(&pcpu_lock); 767b539b87fSTejun Heo 768b539b87fSTejun Heo bitmap_set(chunk->populated, page_start, nr); 769b539b87fSTejun Heo chunk->nr_populated += nr; 770b539b87fSTejun Heo pcpu_nr_empty_pop_pages += nr; 771b539b87fSTejun Heo } 772b539b87fSTejun Heo 773b539b87fSTejun Heo /** 774b539b87fSTejun Heo * pcpu_chunk_depopulated - post-depopulation bookkeeping 775b539b87fSTejun Heo * @chunk: pcpu_chunk which got depopulated 776b539b87fSTejun Heo * @page_start: the start page 777b539b87fSTejun Heo * @page_end: the end page 778b539b87fSTejun Heo * 779b539b87fSTejun Heo * Pages in [@page_start,@page_end) have been depopulated from @chunk. 780b539b87fSTejun Heo * Update the bookkeeping information accordingly. Must be called after 781b539b87fSTejun Heo * each successful depopulation. 782b539b87fSTejun Heo */ 783b539b87fSTejun Heo static void pcpu_chunk_depopulated(struct pcpu_chunk *chunk, 784b539b87fSTejun Heo int page_start, int page_end) 785b539b87fSTejun Heo { 786b539b87fSTejun Heo int nr = page_end - page_start; 787b539b87fSTejun Heo 788b539b87fSTejun Heo lockdep_assert_held(&pcpu_lock); 789b539b87fSTejun Heo 790b539b87fSTejun Heo bitmap_clear(chunk->populated, page_start, nr); 791b539b87fSTejun Heo chunk->nr_populated -= nr; 792b539b87fSTejun Heo pcpu_nr_empty_pop_pages -= nr; 793b539b87fSTejun Heo } 794b539b87fSTejun Heo 795fbf59bc9STejun Heo /* 7969f645532STejun Heo * Chunk management implementation. 797fbf59bc9STejun Heo * 7989f645532STejun Heo * To allow different implementations, chunk alloc/free and 7999f645532STejun Heo * [de]population are implemented in a separate file which is pulled 8009f645532STejun Heo * into this file and compiled together. The following functions 8019f645532STejun Heo * should be implemented. 802ccea34b5STejun Heo * 8039f645532STejun Heo * pcpu_populate_chunk - populate the specified range of a chunk 8049f645532STejun Heo * pcpu_depopulate_chunk - depopulate the specified range of a chunk 8059f645532STejun Heo * pcpu_create_chunk - create a new chunk 8069f645532STejun Heo * pcpu_destroy_chunk - destroy a chunk, always preceded by full depop 8079f645532STejun Heo * pcpu_addr_to_page - translate address to physical address 8089f645532STejun Heo * pcpu_verify_alloc_info - check alloc_info is acceptable during init 809fbf59bc9STejun Heo */ 8109f645532STejun Heo static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size); 8119f645532STejun Heo static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size); 8129f645532STejun Heo static struct pcpu_chunk *pcpu_create_chunk(void); 8139f645532STejun Heo static void pcpu_destroy_chunk(struct pcpu_chunk *chunk); 8149f645532STejun Heo static struct page *pcpu_addr_to_page(void *addr); 8159f645532STejun Heo static int __init pcpu_verify_alloc_info(const struct pcpu_alloc_info *ai); 816fbf59bc9STejun Heo 817b0c9778bSTejun Heo #ifdef CONFIG_NEED_PER_CPU_KM 818b0c9778bSTejun Heo #include "percpu-km.c" 819b0c9778bSTejun Heo #else 8209f645532STejun Heo #include "percpu-vm.c" 821b0c9778bSTejun Heo #endif 822fbf59bc9STejun Heo 823fbf59bc9STejun Heo /** 82488999a89STejun Heo * pcpu_chunk_addr_search - determine chunk containing specified address 82588999a89STejun Heo * @addr: address for which the chunk needs to be determined. 82688999a89STejun Heo * 82788999a89STejun Heo * RETURNS: 82888999a89STejun Heo * The address of the found chunk. 82988999a89STejun Heo */ 83088999a89STejun Heo static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr) 83188999a89STejun Heo { 83288999a89STejun Heo /* is it in the first chunk? */ 83388999a89STejun Heo if (pcpu_addr_in_first_chunk(addr)) { 83488999a89STejun Heo /* is it in the reserved area? */ 83588999a89STejun Heo if (pcpu_addr_in_reserved_chunk(addr)) 83688999a89STejun Heo return pcpu_reserved_chunk; 83788999a89STejun Heo return pcpu_first_chunk; 83888999a89STejun Heo } 83988999a89STejun Heo 84088999a89STejun Heo /* 84188999a89STejun Heo * The address is relative to unit0 which might be unused and 84288999a89STejun Heo * thus unmapped. Offset the address to the unit space of the 84388999a89STejun Heo * current processor before looking it up in the vmalloc 84488999a89STejun Heo * space. Note that any possible cpu id can be used here, so 84588999a89STejun Heo * there's no need to worry about preemption or cpu hotplug. 84688999a89STejun Heo */ 84788999a89STejun Heo addr += pcpu_unit_offsets[raw_smp_processor_id()]; 8489f645532STejun Heo return pcpu_get_page_chunk(pcpu_addr_to_page(addr)); 84988999a89STejun Heo } 85088999a89STejun Heo 85188999a89STejun Heo /** 852edcb4639STejun Heo * pcpu_alloc - the percpu allocator 853cae3aeb8STejun Heo * @size: size of area to allocate in bytes 854fbf59bc9STejun Heo * @align: alignment of area (max PAGE_SIZE) 855edcb4639STejun Heo * @reserved: allocate from the reserved chunk if available 8565835d96eSTejun Heo * @gfp: allocation flags 857fbf59bc9STejun Heo * 8585835d96eSTejun Heo * Allocate percpu area of @size bytes aligned at @align. If @gfp doesn't 8595835d96eSTejun Heo * contain %GFP_KERNEL, the allocation is atomic. 860fbf59bc9STejun Heo * 861fbf59bc9STejun Heo * RETURNS: 862fbf59bc9STejun Heo * Percpu pointer to the allocated area on success, NULL on failure. 863fbf59bc9STejun Heo */ 8645835d96eSTejun Heo static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved, 8655835d96eSTejun Heo gfp_t gfp) 866fbf59bc9STejun Heo { 867f2badb0cSTejun Heo static int warn_limit = 10; 868fbf59bc9STejun Heo struct pcpu_chunk *chunk; 869f2badb0cSTejun Heo const char *err; 8706ae833c7STejun Heo bool is_atomic = (gfp & GFP_KERNEL) != GFP_KERNEL; 871b539b87fSTejun Heo int occ_pages = 0; 872b38d08f3STejun Heo int slot, off, new_alloc, cpu, ret; 873403a91b1SJiri Kosina unsigned long flags; 874f528f0b8SCatalin Marinas void __percpu *ptr; 875fbf59bc9STejun Heo 876723ad1d9SAl Viro /* 877723ad1d9SAl Viro * We want the lowest bit of offset available for in-use/free 8782f69fa82SViro * indicator, so force >= 16bit alignment and make size even. 879723ad1d9SAl Viro */ 880723ad1d9SAl Viro if (unlikely(align < 2)) 881723ad1d9SAl Viro align = 2; 882723ad1d9SAl Viro 883fb009e3aSChristoph Lameter size = ALIGN(size, 2); 8842f69fa82SViro 8853ca45a46Szijun_hu if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE || 8863ca45a46Szijun_hu !is_power_of_2(align))) { 887756a025fSJoe Perches WARN(true, "illegal size (%zu) or align (%zu) for percpu allocation\n", 888756a025fSJoe Perches size, align); 889fbf59bc9STejun Heo return NULL; 890fbf59bc9STejun Heo } 891fbf59bc9STejun Heo 8926710e594STejun Heo if (!is_atomic) 8936710e594STejun Heo mutex_lock(&pcpu_alloc_mutex); 8946710e594STejun Heo 895403a91b1SJiri Kosina spin_lock_irqsave(&pcpu_lock, flags); 896fbf59bc9STejun Heo 897edcb4639STejun Heo /* serve reserved allocations from the reserved chunk if available */ 898edcb4639STejun Heo if (reserved && pcpu_reserved_chunk) { 899edcb4639STejun Heo chunk = pcpu_reserved_chunk; 900833af842STejun Heo 901833af842STejun Heo if (size > chunk->contig_hint) { 902833af842STejun Heo err = "alloc from reserved chunk failed"; 903ccea34b5STejun Heo goto fail_unlock; 904f2badb0cSTejun Heo } 905833af842STejun Heo 9069c824b6aSTejun Heo while ((new_alloc = pcpu_need_to_extend(chunk, is_atomic))) { 907833af842STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 9085835d96eSTejun Heo if (is_atomic || 9095835d96eSTejun Heo pcpu_extend_area_map(chunk, new_alloc) < 0) { 910833af842STejun Heo err = "failed to extend area map of reserved chunk"; 911b38d08f3STejun Heo goto fail; 912833af842STejun Heo } 913833af842STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 914833af842STejun Heo } 915833af842STejun Heo 916b539b87fSTejun Heo off = pcpu_alloc_area(chunk, size, align, is_atomic, 917b539b87fSTejun Heo &occ_pages); 918edcb4639STejun Heo if (off >= 0) 919edcb4639STejun Heo goto area_found; 920833af842STejun Heo 921f2badb0cSTejun Heo err = "alloc from reserved chunk failed"; 922ccea34b5STejun Heo goto fail_unlock; 923edcb4639STejun Heo } 924edcb4639STejun Heo 925ccea34b5STejun Heo restart: 926edcb4639STejun Heo /* search through normal chunks */ 927fbf59bc9STejun Heo for (slot = pcpu_size_to_slot(size); slot < pcpu_nr_slots; slot++) { 928fbf59bc9STejun Heo list_for_each_entry(chunk, &pcpu_slot[slot], list) { 929fbf59bc9STejun Heo if (size > chunk->contig_hint) 930fbf59bc9STejun Heo continue; 931ccea34b5STejun Heo 9329c824b6aSTejun Heo new_alloc = pcpu_need_to_extend(chunk, is_atomic); 933833af842STejun Heo if (new_alloc) { 9345835d96eSTejun Heo if (is_atomic) 9355835d96eSTejun Heo continue; 936833af842STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 937833af842STejun Heo if (pcpu_extend_area_map(chunk, 938833af842STejun Heo new_alloc) < 0) { 939f2badb0cSTejun Heo err = "failed to extend area map"; 940b38d08f3STejun Heo goto fail; 941833af842STejun Heo } 942833af842STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 943833af842STejun Heo /* 944833af842STejun Heo * pcpu_lock has been dropped, need to 945833af842STejun Heo * restart cpu_slot list walking. 946833af842STejun Heo */ 947833af842STejun Heo goto restart; 948ccea34b5STejun Heo } 949ccea34b5STejun Heo 950b539b87fSTejun Heo off = pcpu_alloc_area(chunk, size, align, is_atomic, 951b539b87fSTejun Heo &occ_pages); 952fbf59bc9STejun Heo if (off >= 0) 953fbf59bc9STejun Heo goto area_found; 954fbf59bc9STejun Heo } 955fbf59bc9STejun Heo } 956fbf59bc9STejun Heo 957403a91b1SJiri Kosina spin_unlock_irqrestore(&pcpu_lock, flags); 958ccea34b5STejun Heo 959b38d08f3STejun Heo /* 960b38d08f3STejun Heo * No space left. Create a new chunk. We don't want multiple 961b38d08f3STejun Heo * tasks to create chunks simultaneously. Serialize and create iff 962b38d08f3STejun Heo * there's still no empty chunk after grabbing the mutex. 963b38d08f3STejun Heo */ 96411df02bfSDennis Zhou if (is_atomic) { 96511df02bfSDennis Zhou err = "atomic alloc failed, no space left"; 9665835d96eSTejun Heo goto fail; 96711df02bfSDennis Zhou } 9685835d96eSTejun Heo 969b38d08f3STejun Heo if (list_empty(&pcpu_slot[pcpu_nr_slots - 1])) { 9706081089fSTejun Heo chunk = pcpu_create_chunk(); 971f2badb0cSTejun Heo if (!chunk) { 972f2badb0cSTejun Heo err = "failed to allocate new chunk"; 973b38d08f3STejun Heo goto fail; 974f2badb0cSTejun Heo } 975ccea34b5STejun Heo 976403a91b1SJiri Kosina spin_lock_irqsave(&pcpu_lock, flags); 977fbf59bc9STejun Heo pcpu_chunk_relocate(chunk, -1); 978b38d08f3STejun Heo } else { 979b38d08f3STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 980b38d08f3STejun Heo } 981b38d08f3STejun Heo 982ccea34b5STejun Heo goto restart; 983fbf59bc9STejun Heo 984fbf59bc9STejun Heo area_found: 98530a5b536SDennis Zhou pcpu_stats_area_alloc(chunk, size); 986403a91b1SJiri Kosina spin_unlock_irqrestore(&pcpu_lock, flags); 987ccea34b5STejun Heo 988dca49645STejun Heo /* populate if not all pages are already there */ 9895835d96eSTejun Heo if (!is_atomic) { 990e04d3208STejun Heo int page_start, page_end, rs, re; 991e04d3208STejun Heo 992dca49645STejun Heo page_start = PFN_DOWN(off); 993dca49645STejun Heo page_end = PFN_UP(off + size); 994dca49645STejun Heo 995a93ace48STejun Heo pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) { 996dca49645STejun Heo WARN_ON(chunk->immutable); 997dca49645STejun Heo 998b38d08f3STejun Heo ret = pcpu_populate_chunk(chunk, rs, re); 999b38d08f3STejun Heo 1000403a91b1SJiri Kosina spin_lock_irqsave(&pcpu_lock, flags); 1001b38d08f3STejun Heo if (ret) { 1002b539b87fSTejun Heo pcpu_free_area(chunk, off, &occ_pages); 1003f2badb0cSTejun Heo err = "failed to populate"; 1004ccea34b5STejun Heo goto fail_unlock; 1005fbf59bc9STejun Heo } 1006b539b87fSTejun Heo pcpu_chunk_populated(chunk, rs, re); 1007b38d08f3STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 1008dca49645STejun Heo } 1009dca49645STejun Heo 1010ccea34b5STejun Heo mutex_unlock(&pcpu_alloc_mutex); 1011e04d3208STejun Heo } 1012ccea34b5STejun Heo 1013320661b0STahsin Erdogan if (chunk != pcpu_reserved_chunk) { 1014320661b0STahsin Erdogan spin_lock_irqsave(&pcpu_lock, flags); 1015b539b87fSTejun Heo pcpu_nr_empty_pop_pages -= occ_pages; 1016320661b0STahsin Erdogan spin_unlock_irqrestore(&pcpu_lock, flags); 1017320661b0STahsin Erdogan } 1018b539b87fSTejun Heo 10191a4d7607STejun Heo if (pcpu_nr_empty_pop_pages < PCPU_EMPTY_POP_PAGES_LOW) 10201a4d7607STejun Heo pcpu_schedule_balance_work(); 10211a4d7607STejun Heo 1022dca49645STejun Heo /* clear the areas and return address relative to base address */ 1023dca49645STejun Heo for_each_possible_cpu(cpu) 1024dca49645STejun Heo memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size); 1025dca49645STejun Heo 1026f528f0b8SCatalin Marinas ptr = __addr_to_pcpu_ptr(chunk->base_addr + off); 10278a8c35faSLarry Finger kmemleak_alloc_percpu(ptr, size, gfp); 1028df95e795SDennis Zhou 1029df95e795SDennis Zhou trace_percpu_alloc_percpu(reserved, is_atomic, size, align, 1030df95e795SDennis Zhou chunk->base_addr, off, ptr); 1031df95e795SDennis Zhou 1032f528f0b8SCatalin Marinas return ptr; 1033ccea34b5STejun Heo 1034ccea34b5STejun Heo fail_unlock: 1035403a91b1SJiri Kosina spin_unlock_irqrestore(&pcpu_lock, flags); 1036b38d08f3STejun Heo fail: 1037df95e795SDennis Zhou trace_percpu_alloc_percpu_fail(reserved, is_atomic, size, align); 1038df95e795SDennis Zhou 10395835d96eSTejun Heo if (!is_atomic && warn_limit) { 1040870d4b12SJoe Perches pr_warn("allocation failed, size=%zu align=%zu atomic=%d, %s\n", 10415835d96eSTejun Heo size, align, is_atomic, err); 1042f2badb0cSTejun Heo dump_stack(); 1043f2badb0cSTejun Heo if (!--warn_limit) 1044870d4b12SJoe Perches pr_info("limit reached, disable warning\n"); 1045f2badb0cSTejun Heo } 10461a4d7607STejun Heo if (is_atomic) { 10471a4d7607STejun Heo /* see the flag handling in pcpu_blance_workfn() */ 10481a4d7607STejun Heo pcpu_atomic_alloc_failed = true; 10491a4d7607STejun Heo pcpu_schedule_balance_work(); 10506710e594STejun Heo } else { 10516710e594STejun Heo mutex_unlock(&pcpu_alloc_mutex); 10521a4d7607STejun Heo } 1053ccea34b5STejun Heo return NULL; 1054fbf59bc9STejun Heo } 1055edcb4639STejun Heo 1056edcb4639STejun Heo /** 10575835d96eSTejun Heo * __alloc_percpu_gfp - allocate dynamic percpu area 1058edcb4639STejun Heo * @size: size of area to allocate in bytes 1059edcb4639STejun Heo * @align: alignment of area (max PAGE_SIZE) 10605835d96eSTejun Heo * @gfp: allocation flags 1061edcb4639STejun Heo * 10625835d96eSTejun Heo * Allocate zero-filled percpu area of @size bytes aligned at @align. If 10635835d96eSTejun Heo * @gfp doesn't contain %GFP_KERNEL, the allocation doesn't block and can 10645835d96eSTejun Heo * be called from any context but is a lot more likely to fail. 1065ccea34b5STejun Heo * 1066edcb4639STejun Heo * RETURNS: 1067edcb4639STejun Heo * Percpu pointer to the allocated area on success, NULL on failure. 1068edcb4639STejun Heo */ 10695835d96eSTejun Heo void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp) 10705835d96eSTejun Heo { 10715835d96eSTejun Heo return pcpu_alloc(size, align, false, gfp); 10725835d96eSTejun Heo } 10735835d96eSTejun Heo EXPORT_SYMBOL_GPL(__alloc_percpu_gfp); 10745835d96eSTejun Heo 10755835d96eSTejun Heo /** 10765835d96eSTejun Heo * __alloc_percpu - allocate dynamic percpu area 10775835d96eSTejun Heo * @size: size of area to allocate in bytes 10785835d96eSTejun Heo * @align: alignment of area (max PAGE_SIZE) 10795835d96eSTejun Heo * 10805835d96eSTejun Heo * Equivalent to __alloc_percpu_gfp(size, align, %GFP_KERNEL). 10815835d96eSTejun Heo */ 108243cf38ebSTejun Heo void __percpu *__alloc_percpu(size_t size, size_t align) 1083edcb4639STejun Heo { 10845835d96eSTejun Heo return pcpu_alloc(size, align, false, GFP_KERNEL); 1085edcb4639STejun Heo } 1086fbf59bc9STejun Heo EXPORT_SYMBOL_GPL(__alloc_percpu); 1087fbf59bc9STejun Heo 1088edcb4639STejun Heo /** 1089edcb4639STejun Heo * __alloc_reserved_percpu - allocate reserved percpu area 1090edcb4639STejun Heo * @size: size of area to allocate in bytes 1091edcb4639STejun Heo * @align: alignment of area (max PAGE_SIZE) 1092edcb4639STejun Heo * 10939329ba97STejun Heo * Allocate zero-filled percpu area of @size bytes aligned at @align 10949329ba97STejun Heo * from reserved percpu area if arch has set it up; otherwise, 10959329ba97STejun Heo * allocation is served from the same dynamic area. Might sleep. 10969329ba97STejun Heo * Might trigger writeouts. 1097edcb4639STejun Heo * 1098ccea34b5STejun Heo * CONTEXT: 1099ccea34b5STejun Heo * Does GFP_KERNEL allocation. 1100ccea34b5STejun Heo * 1101edcb4639STejun Heo * RETURNS: 1102edcb4639STejun Heo * Percpu pointer to the allocated area on success, NULL on failure. 1103edcb4639STejun Heo */ 110443cf38ebSTejun Heo void __percpu *__alloc_reserved_percpu(size_t size, size_t align) 1105edcb4639STejun Heo { 11065835d96eSTejun Heo return pcpu_alloc(size, align, true, GFP_KERNEL); 1107edcb4639STejun Heo } 1108edcb4639STejun Heo 1109a56dbddfSTejun Heo /** 11101a4d7607STejun Heo * pcpu_balance_workfn - manage the amount of free chunks and populated pages 1111a56dbddfSTejun Heo * @work: unused 1112a56dbddfSTejun Heo * 1113a56dbddfSTejun Heo * Reclaim all fully free chunks except for the first one. 1114a56dbddfSTejun Heo */ 1115fe6bd8c3STejun Heo static void pcpu_balance_workfn(struct work_struct *work) 1116fbf59bc9STejun Heo { 1117fe6bd8c3STejun Heo LIST_HEAD(to_free); 1118fe6bd8c3STejun Heo struct list_head *free_head = &pcpu_slot[pcpu_nr_slots - 1]; 1119a56dbddfSTejun Heo struct pcpu_chunk *chunk, *next; 11201a4d7607STejun Heo int slot, nr_to_pop, ret; 1121a56dbddfSTejun Heo 11221a4d7607STejun Heo /* 11231a4d7607STejun Heo * There's no reason to keep around multiple unused chunks and VM 11241a4d7607STejun Heo * areas can be scarce. Destroy all free chunks except for one. 11251a4d7607STejun Heo */ 1126ccea34b5STejun Heo mutex_lock(&pcpu_alloc_mutex); 1127ccea34b5STejun Heo spin_lock_irq(&pcpu_lock); 1128a56dbddfSTejun Heo 1129fe6bd8c3STejun Heo list_for_each_entry_safe(chunk, next, free_head, list) { 11308d408b4bSTejun Heo WARN_ON(chunk->immutable); 1131a56dbddfSTejun Heo 1132a56dbddfSTejun Heo /* spare the first one */ 1133fe6bd8c3STejun Heo if (chunk == list_first_entry(free_head, struct pcpu_chunk, list)) 1134a56dbddfSTejun Heo continue; 1135a56dbddfSTejun Heo 11364f996e23STejun Heo list_del_init(&chunk->map_extend_list); 1137fe6bd8c3STejun Heo list_move(&chunk->list, &to_free); 1138a56dbddfSTejun Heo } 1139a56dbddfSTejun Heo 1140ccea34b5STejun Heo spin_unlock_irq(&pcpu_lock); 1141a56dbddfSTejun Heo 1142fe6bd8c3STejun Heo list_for_each_entry_safe(chunk, next, &to_free, list) { 1143a93ace48STejun Heo int rs, re; 1144dca49645STejun Heo 1145a93ace48STejun Heo pcpu_for_each_pop_region(chunk, rs, re, 0, pcpu_unit_pages) { 1146a93ace48STejun Heo pcpu_depopulate_chunk(chunk, rs, re); 1147b539b87fSTejun Heo spin_lock_irq(&pcpu_lock); 1148b539b87fSTejun Heo pcpu_chunk_depopulated(chunk, rs, re); 1149b539b87fSTejun Heo spin_unlock_irq(&pcpu_lock); 1150a93ace48STejun Heo } 11516081089fSTejun Heo pcpu_destroy_chunk(chunk); 1152fbf59bc9STejun Heo } 1153971f3918STejun Heo 11544f996e23STejun Heo /* service chunks which requested async area map extension */ 11554f996e23STejun Heo do { 11564f996e23STejun Heo int new_alloc = 0; 11574f996e23STejun Heo 11584f996e23STejun Heo spin_lock_irq(&pcpu_lock); 11594f996e23STejun Heo 11604f996e23STejun Heo chunk = list_first_entry_or_null(&pcpu_map_extend_chunks, 11614f996e23STejun Heo struct pcpu_chunk, map_extend_list); 11624f996e23STejun Heo if (chunk) { 11634f996e23STejun Heo list_del_init(&chunk->map_extend_list); 11644f996e23STejun Heo new_alloc = pcpu_need_to_extend(chunk, false); 11654f996e23STejun Heo } 11664f996e23STejun Heo 11674f996e23STejun Heo spin_unlock_irq(&pcpu_lock); 11684f996e23STejun Heo 11694f996e23STejun Heo if (new_alloc) 11704f996e23STejun Heo pcpu_extend_area_map(chunk, new_alloc); 11714f996e23STejun Heo } while (chunk); 11724f996e23STejun Heo 11731a4d7607STejun Heo /* 11741a4d7607STejun Heo * Ensure there are certain number of free populated pages for 11751a4d7607STejun Heo * atomic allocs. Fill up from the most packed so that atomic 11761a4d7607STejun Heo * allocs don't increase fragmentation. If atomic allocation 11771a4d7607STejun Heo * failed previously, always populate the maximum amount. This 11781a4d7607STejun Heo * should prevent atomic allocs larger than PAGE_SIZE from keeping 11791a4d7607STejun Heo * failing indefinitely; however, large atomic allocs are not 11801a4d7607STejun Heo * something we support properly and can be highly unreliable and 11811a4d7607STejun Heo * inefficient. 11821a4d7607STejun Heo */ 11831a4d7607STejun Heo retry_pop: 11841a4d7607STejun Heo if (pcpu_atomic_alloc_failed) { 11851a4d7607STejun Heo nr_to_pop = PCPU_EMPTY_POP_PAGES_HIGH; 11861a4d7607STejun Heo /* best effort anyway, don't worry about synchronization */ 11871a4d7607STejun Heo pcpu_atomic_alloc_failed = false; 11881a4d7607STejun Heo } else { 11891a4d7607STejun Heo nr_to_pop = clamp(PCPU_EMPTY_POP_PAGES_HIGH - 11901a4d7607STejun Heo pcpu_nr_empty_pop_pages, 11911a4d7607STejun Heo 0, PCPU_EMPTY_POP_PAGES_HIGH); 11921a4d7607STejun Heo } 11931a4d7607STejun Heo 11941a4d7607STejun Heo for (slot = pcpu_size_to_slot(PAGE_SIZE); slot < pcpu_nr_slots; slot++) { 11951a4d7607STejun Heo int nr_unpop = 0, rs, re; 11961a4d7607STejun Heo 11971a4d7607STejun Heo if (!nr_to_pop) 11981a4d7607STejun Heo break; 11991a4d7607STejun Heo 12001a4d7607STejun Heo spin_lock_irq(&pcpu_lock); 12011a4d7607STejun Heo list_for_each_entry(chunk, &pcpu_slot[slot], list) { 12021a4d7607STejun Heo nr_unpop = pcpu_unit_pages - chunk->nr_populated; 12031a4d7607STejun Heo if (nr_unpop) 12041a4d7607STejun Heo break; 12051a4d7607STejun Heo } 12061a4d7607STejun Heo spin_unlock_irq(&pcpu_lock); 12071a4d7607STejun Heo 12081a4d7607STejun Heo if (!nr_unpop) 12091a4d7607STejun Heo continue; 12101a4d7607STejun Heo 12111a4d7607STejun Heo /* @chunk can't go away while pcpu_alloc_mutex is held */ 12121a4d7607STejun Heo pcpu_for_each_unpop_region(chunk, rs, re, 0, pcpu_unit_pages) { 12131a4d7607STejun Heo int nr = min(re - rs, nr_to_pop); 12141a4d7607STejun Heo 12151a4d7607STejun Heo ret = pcpu_populate_chunk(chunk, rs, rs + nr); 12161a4d7607STejun Heo if (!ret) { 12171a4d7607STejun Heo nr_to_pop -= nr; 12181a4d7607STejun Heo spin_lock_irq(&pcpu_lock); 12191a4d7607STejun Heo pcpu_chunk_populated(chunk, rs, rs + nr); 12201a4d7607STejun Heo spin_unlock_irq(&pcpu_lock); 12211a4d7607STejun Heo } else { 12221a4d7607STejun Heo nr_to_pop = 0; 12231a4d7607STejun Heo } 12241a4d7607STejun Heo 12251a4d7607STejun Heo if (!nr_to_pop) 12261a4d7607STejun Heo break; 12271a4d7607STejun Heo } 12281a4d7607STejun Heo } 12291a4d7607STejun Heo 12301a4d7607STejun Heo if (nr_to_pop) { 12311a4d7607STejun Heo /* ran out of chunks to populate, create a new one and retry */ 12321a4d7607STejun Heo chunk = pcpu_create_chunk(); 12331a4d7607STejun Heo if (chunk) { 12341a4d7607STejun Heo spin_lock_irq(&pcpu_lock); 12351a4d7607STejun Heo pcpu_chunk_relocate(chunk, -1); 12361a4d7607STejun Heo spin_unlock_irq(&pcpu_lock); 12371a4d7607STejun Heo goto retry_pop; 12381a4d7607STejun Heo } 12391a4d7607STejun Heo } 12401a4d7607STejun Heo 1241971f3918STejun Heo mutex_unlock(&pcpu_alloc_mutex); 1242a56dbddfSTejun Heo } 1243fbf59bc9STejun Heo 1244fbf59bc9STejun Heo /** 1245fbf59bc9STejun Heo * free_percpu - free percpu area 1246fbf59bc9STejun Heo * @ptr: pointer to area to free 1247fbf59bc9STejun Heo * 1248ccea34b5STejun Heo * Free percpu area @ptr. 1249ccea34b5STejun Heo * 1250ccea34b5STejun Heo * CONTEXT: 1251ccea34b5STejun Heo * Can be called from atomic context. 1252fbf59bc9STejun Heo */ 125343cf38ebSTejun Heo void free_percpu(void __percpu *ptr) 1254fbf59bc9STejun Heo { 1255129182e5SAndrew Morton void *addr; 1256fbf59bc9STejun Heo struct pcpu_chunk *chunk; 1257ccea34b5STejun Heo unsigned long flags; 1258b539b87fSTejun Heo int off, occ_pages; 1259fbf59bc9STejun Heo 1260fbf59bc9STejun Heo if (!ptr) 1261fbf59bc9STejun Heo return; 1262fbf59bc9STejun Heo 1263f528f0b8SCatalin Marinas kmemleak_free_percpu(ptr); 1264f528f0b8SCatalin Marinas 1265129182e5SAndrew Morton addr = __pcpu_ptr_to_addr(ptr); 1266129182e5SAndrew Morton 1267ccea34b5STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 1268fbf59bc9STejun Heo 1269fbf59bc9STejun Heo chunk = pcpu_chunk_addr_search(addr); 1270bba174f5STejun Heo off = addr - chunk->base_addr; 1271fbf59bc9STejun Heo 1272b539b87fSTejun Heo pcpu_free_area(chunk, off, &occ_pages); 1273b539b87fSTejun Heo 1274b539b87fSTejun Heo if (chunk != pcpu_reserved_chunk) 1275b539b87fSTejun Heo pcpu_nr_empty_pop_pages += occ_pages; 1276fbf59bc9STejun Heo 1277a56dbddfSTejun Heo /* if there are more than one fully free chunks, wake up grim reaper */ 1278fbf59bc9STejun Heo if (chunk->free_size == pcpu_unit_size) { 1279fbf59bc9STejun Heo struct pcpu_chunk *pos; 1280fbf59bc9STejun Heo 1281a56dbddfSTejun Heo list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list) 1282fbf59bc9STejun Heo if (pos != chunk) { 12831a4d7607STejun Heo pcpu_schedule_balance_work(); 1284fbf59bc9STejun Heo break; 1285fbf59bc9STejun Heo } 1286fbf59bc9STejun Heo } 1287fbf59bc9STejun Heo 1288df95e795SDennis Zhou trace_percpu_free_percpu(chunk->base_addr, off, ptr); 1289df95e795SDennis Zhou 1290ccea34b5STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 1291fbf59bc9STejun Heo } 1292fbf59bc9STejun Heo EXPORT_SYMBOL_GPL(free_percpu); 1293fbf59bc9STejun Heo 1294383776faSThomas Gleixner bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr) 1295383776faSThomas Gleixner { 1296383776faSThomas Gleixner #ifdef CONFIG_SMP 1297383776faSThomas Gleixner const size_t static_size = __per_cpu_end - __per_cpu_start; 1298383776faSThomas Gleixner void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr); 1299383776faSThomas Gleixner unsigned int cpu; 1300383776faSThomas Gleixner 1301383776faSThomas Gleixner for_each_possible_cpu(cpu) { 1302383776faSThomas Gleixner void *start = per_cpu_ptr(base, cpu); 1303383776faSThomas Gleixner void *va = (void *)addr; 1304383776faSThomas Gleixner 1305383776faSThomas Gleixner if (va >= start && va < start + static_size) { 13068ce371f9SPeter Zijlstra if (can_addr) { 1307383776faSThomas Gleixner *can_addr = (unsigned long) (va - start); 13088ce371f9SPeter Zijlstra *can_addr += (unsigned long) 13098ce371f9SPeter Zijlstra per_cpu_ptr(base, get_boot_cpu_id()); 13108ce371f9SPeter Zijlstra } 1311383776faSThomas Gleixner return true; 1312383776faSThomas Gleixner } 1313383776faSThomas Gleixner } 1314383776faSThomas Gleixner #endif 1315383776faSThomas Gleixner /* on UP, can't distinguish from other static vars, always false */ 1316383776faSThomas Gleixner return false; 1317383776faSThomas Gleixner } 1318383776faSThomas Gleixner 13193b034b0dSVivek Goyal /** 132010fad5e4STejun Heo * is_kernel_percpu_address - test whether address is from static percpu area 132110fad5e4STejun Heo * @addr: address to test 132210fad5e4STejun Heo * 132310fad5e4STejun Heo * Test whether @addr belongs to in-kernel static percpu area. Module 132410fad5e4STejun Heo * static percpu areas are not considered. For those, use 132510fad5e4STejun Heo * is_module_percpu_address(). 132610fad5e4STejun Heo * 132710fad5e4STejun Heo * RETURNS: 132810fad5e4STejun Heo * %true if @addr is from in-kernel static percpu area, %false otherwise. 132910fad5e4STejun Heo */ 133010fad5e4STejun Heo bool is_kernel_percpu_address(unsigned long addr) 133110fad5e4STejun Heo { 1332383776faSThomas Gleixner return __is_kernel_percpu_address(addr, NULL); 133310fad5e4STejun Heo } 133410fad5e4STejun Heo 133510fad5e4STejun Heo /** 13363b034b0dSVivek Goyal * per_cpu_ptr_to_phys - convert translated percpu address to physical address 13373b034b0dSVivek Goyal * @addr: the address to be converted to physical address 13383b034b0dSVivek Goyal * 13393b034b0dSVivek Goyal * Given @addr which is dereferenceable address obtained via one of 13403b034b0dSVivek Goyal * percpu access macros, this function translates it into its physical 13413b034b0dSVivek Goyal * address. The caller is responsible for ensuring @addr stays valid 13423b034b0dSVivek Goyal * until this function finishes. 13433b034b0dSVivek Goyal * 134467589c71SDave Young * percpu allocator has special setup for the first chunk, which currently 134567589c71SDave Young * supports either embedding in linear address space or vmalloc mapping, 134667589c71SDave Young * and, from the second one, the backing allocator (currently either vm or 134767589c71SDave Young * km) provides translation. 134867589c71SDave Young * 1349bffc4375SYannick Guerrini * The addr can be translated simply without checking if it falls into the 135067589c71SDave Young * first chunk. But the current code reflects better how percpu allocator 135167589c71SDave Young * actually works, and the verification can discover both bugs in percpu 135267589c71SDave Young * allocator itself and per_cpu_ptr_to_phys() callers. So we keep current 135367589c71SDave Young * code. 135467589c71SDave Young * 13553b034b0dSVivek Goyal * RETURNS: 13563b034b0dSVivek Goyal * The physical address for @addr. 13573b034b0dSVivek Goyal */ 13583b034b0dSVivek Goyal phys_addr_t per_cpu_ptr_to_phys(void *addr) 13593b034b0dSVivek Goyal { 13609983b6f0STejun Heo void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr); 13619983b6f0STejun Heo bool in_first_chunk = false; 1362a855b84cSTejun Heo unsigned long first_low, first_high; 13639983b6f0STejun Heo unsigned int cpu; 13649983b6f0STejun Heo 13659983b6f0STejun Heo /* 1366a855b84cSTejun Heo * The following test on unit_low/high isn't strictly 13679983b6f0STejun Heo * necessary but will speed up lookups of addresses which 13689983b6f0STejun Heo * aren't in the first chunk. 13699983b6f0STejun Heo */ 1370a855b84cSTejun Heo first_low = pcpu_chunk_addr(pcpu_first_chunk, pcpu_low_unit_cpu, 0); 1371a855b84cSTejun Heo first_high = pcpu_chunk_addr(pcpu_first_chunk, pcpu_high_unit_cpu, 13729983b6f0STejun Heo pcpu_unit_pages); 1373a855b84cSTejun Heo if ((unsigned long)addr >= first_low && 1374a855b84cSTejun Heo (unsigned long)addr < first_high) { 13759983b6f0STejun Heo for_each_possible_cpu(cpu) { 13769983b6f0STejun Heo void *start = per_cpu_ptr(base, cpu); 13779983b6f0STejun Heo 13789983b6f0STejun Heo if (addr >= start && addr < start + pcpu_unit_size) { 13799983b6f0STejun Heo in_first_chunk = true; 13809983b6f0STejun Heo break; 13819983b6f0STejun Heo } 13829983b6f0STejun Heo } 13839983b6f0STejun Heo } 13849983b6f0STejun Heo 13859983b6f0STejun Heo if (in_first_chunk) { 1386eac522efSDavid Howells if (!is_vmalloc_addr(addr)) 13873b034b0dSVivek Goyal return __pa(addr); 13883b034b0dSVivek Goyal else 13899f57bd4dSEugene Surovegin return page_to_phys(vmalloc_to_page(addr)) + 13909f57bd4dSEugene Surovegin offset_in_page(addr); 1391020ec653STejun Heo } else 13929f57bd4dSEugene Surovegin return page_to_phys(pcpu_addr_to_page(addr)) + 13939f57bd4dSEugene Surovegin offset_in_page(addr); 13943b034b0dSVivek Goyal } 13953b034b0dSVivek Goyal 1396fbf59bc9STejun Heo /** 1397fd1e8a1fSTejun Heo * pcpu_alloc_alloc_info - allocate percpu allocation info 1398fd1e8a1fSTejun Heo * @nr_groups: the number of groups 1399fd1e8a1fSTejun Heo * @nr_units: the number of units 1400033e48fbSTejun Heo * 1401fd1e8a1fSTejun Heo * Allocate ai which is large enough for @nr_groups groups containing 1402fd1e8a1fSTejun Heo * @nr_units units. The returned ai's groups[0].cpu_map points to the 1403fd1e8a1fSTejun Heo * cpu_map array which is long enough for @nr_units and filled with 1404fd1e8a1fSTejun Heo * NR_CPUS. It's the caller's responsibility to initialize cpu_map 1405fd1e8a1fSTejun Heo * pointer of other groups. 1406033e48fbSTejun Heo * 1407033e48fbSTejun Heo * RETURNS: 1408fd1e8a1fSTejun Heo * Pointer to the allocated pcpu_alloc_info on success, NULL on 1409fd1e8a1fSTejun Heo * failure. 1410033e48fbSTejun Heo */ 1411fd1e8a1fSTejun Heo struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, 1412fd1e8a1fSTejun Heo int nr_units) 1413fd1e8a1fSTejun Heo { 1414fd1e8a1fSTejun Heo struct pcpu_alloc_info *ai; 1415fd1e8a1fSTejun Heo size_t base_size, ai_size; 1416fd1e8a1fSTejun Heo void *ptr; 1417fd1e8a1fSTejun Heo int unit; 1418fd1e8a1fSTejun Heo 1419fd1e8a1fSTejun Heo base_size = ALIGN(sizeof(*ai) + nr_groups * sizeof(ai->groups[0]), 1420fd1e8a1fSTejun Heo __alignof__(ai->groups[0].cpu_map[0])); 1421fd1e8a1fSTejun Heo ai_size = base_size + nr_units * sizeof(ai->groups[0].cpu_map[0]); 1422fd1e8a1fSTejun Heo 1423999c17e3SSantosh Shilimkar ptr = memblock_virt_alloc_nopanic(PFN_ALIGN(ai_size), 0); 1424fd1e8a1fSTejun Heo if (!ptr) 1425fd1e8a1fSTejun Heo return NULL; 1426fd1e8a1fSTejun Heo ai = ptr; 1427fd1e8a1fSTejun Heo ptr += base_size; 1428fd1e8a1fSTejun Heo 1429fd1e8a1fSTejun Heo ai->groups[0].cpu_map = ptr; 1430fd1e8a1fSTejun Heo 1431fd1e8a1fSTejun Heo for (unit = 0; unit < nr_units; unit++) 1432fd1e8a1fSTejun Heo ai->groups[0].cpu_map[unit] = NR_CPUS; 1433fd1e8a1fSTejun Heo 1434fd1e8a1fSTejun Heo ai->nr_groups = nr_groups; 1435fd1e8a1fSTejun Heo ai->__ai_size = PFN_ALIGN(ai_size); 1436fd1e8a1fSTejun Heo 1437fd1e8a1fSTejun Heo return ai; 1438fd1e8a1fSTejun Heo } 1439fd1e8a1fSTejun Heo 1440fd1e8a1fSTejun Heo /** 1441fd1e8a1fSTejun Heo * pcpu_free_alloc_info - free percpu allocation info 1442fd1e8a1fSTejun Heo * @ai: pcpu_alloc_info to free 1443fd1e8a1fSTejun Heo * 1444fd1e8a1fSTejun Heo * Free @ai which was allocated by pcpu_alloc_alloc_info(). 1445fd1e8a1fSTejun Heo */ 1446fd1e8a1fSTejun Heo void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai) 1447fd1e8a1fSTejun Heo { 1448999c17e3SSantosh Shilimkar memblock_free_early(__pa(ai), ai->__ai_size); 1449fd1e8a1fSTejun Heo } 1450fd1e8a1fSTejun Heo 1451fd1e8a1fSTejun Heo /** 1452fd1e8a1fSTejun Heo * pcpu_dump_alloc_info - print out information about pcpu_alloc_info 1453fd1e8a1fSTejun Heo * @lvl: loglevel 1454fd1e8a1fSTejun Heo * @ai: allocation info to dump 1455fd1e8a1fSTejun Heo * 1456fd1e8a1fSTejun Heo * Print out information about @ai using loglevel @lvl. 1457fd1e8a1fSTejun Heo */ 1458fd1e8a1fSTejun Heo static void pcpu_dump_alloc_info(const char *lvl, 1459fd1e8a1fSTejun Heo const struct pcpu_alloc_info *ai) 1460033e48fbSTejun Heo { 1461fd1e8a1fSTejun Heo int group_width = 1, cpu_width = 1, width; 1462033e48fbSTejun Heo char empty_str[] = "--------"; 1463fd1e8a1fSTejun Heo int alloc = 0, alloc_end = 0; 1464fd1e8a1fSTejun Heo int group, v; 1465fd1e8a1fSTejun Heo int upa, apl; /* units per alloc, allocs per line */ 1466033e48fbSTejun Heo 1467fd1e8a1fSTejun Heo v = ai->nr_groups; 1468033e48fbSTejun Heo while (v /= 10) 1469fd1e8a1fSTejun Heo group_width++; 1470033e48fbSTejun Heo 1471fd1e8a1fSTejun Heo v = num_possible_cpus(); 1472fd1e8a1fSTejun Heo while (v /= 10) 1473fd1e8a1fSTejun Heo cpu_width++; 1474fd1e8a1fSTejun Heo empty_str[min_t(int, cpu_width, sizeof(empty_str) - 1)] = '\0'; 1475033e48fbSTejun Heo 1476fd1e8a1fSTejun Heo upa = ai->alloc_size / ai->unit_size; 1477fd1e8a1fSTejun Heo width = upa * (cpu_width + 1) + group_width + 3; 1478fd1e8a1fSTejun Heo apl = rounddown_pow_of_two(max(60 / width, 1)); 1479033e48fbSTejun Heo 1480fd1e8a1fSTejun Heo printk("%spcpu-alloc: s%zu r%zu d%zu u%zu alloc=%zu*%zu", 1481fd1e8a1fSTejun Heo lvl, ai->static_size, ai->reserved_size, ai->dyn_size, 1482fd1e8a1fSTejun Heo ai->unit_size, ai->alloc_size / ai->atom_size, ai->atom_size); 1483fd1e8a1fSTejun Heo 1484fd1e8a1fSTejun Heo for (group = 0; group < ai->nr_groups; group++) { 1485fd1e8a1fSTejun Heo const struct pcpu_group_info *gi = &ai->groups[group]; 1486fd1e8a1fSTejun Heo int unit = 0, unit_end = 0; 1487fd1e8a1fSTejun Heo 1488fd1e8a1fSTejun Heo BUG_ON(gi->nr_units % upa); 1489fd1e8a1fSTejun Heo for (alloc_end += gi->nr_units / upa; 1490fd1e8a1fSTejun Heo alloc < alloc_end; alloc++) { 1491fd1e8a1fSTejun Heo if (!(alloc % apl)) { 14921170532bSJoe Perches pr_cont("\n"); 1493fd1e8a1fSTejun Heo printk("%spcpu-alloc: ", lvl); 1494033e48fbSTejun Heo } 14951170532bSJoe Perches pr_cont("[%0*d] ", group_width, group); 1496fd1e8a1fSTejun Heo 1497fd1e8a1fSTejun Heo for (unit_end += upa; unit < unit_end; unit++) 1498fd1e8a1fSTejun Heo if (gi->cpu_map[unit] != NR_CPUS) 14991170532bSJoe Perches pr_cont("%0*d ", 15001170532bSJoe Perches cpu_width, gi->cpu_map[unit]); 1501033e48fbSTejun Heo else 15021170532bSJoe Perches pr_cont("%s ", empty_str); 1503033e48fbSTejun Heo } 1504fd1e8a1fSTejun Heo } 15051170532bSJoe Perches pr_cont("\n"); 1506033e48fbSTejun Heo } 1507033e48fbSTejun Heo 1508fbf59bc9STejun Heo /** 15098d408b4bSTejun Heo * pcpu_setup_first_chunk - initialize the first percpu chunk 1510fd1e8a1fSTejun Heo * @ai: pcpu_alloc_info describing how to percpu area is shaped 151138a6be52STejun Heo * @base_addr: mapped address 1512fbf59bc9STejun Heo * 15138d408b4bSTejun Heo * Initialize the first percpu chunk which contains the kernel static 15148d408b4bSTejun Heo * perpcu area. This function is to be called from arch percpu area 151538a6be52STejun Heo * setup path. 15168d408b4bSTejun Heo * 1517fd1e8a1fSTejun Heo * @ai contains all information necessary to initialize the first 1518fd1e8a1fSTejun Heo * chunk and prime the dynamic percpu allocator. 15198d408b4bSTejun Heo * 1520fd1e8a1fSTejun Heo * @ai->static_size is the size of static percpu area. 1521fd1e8a1fSTejun Heo * 1522fd1e8a1fSTejun Heo * @ai->reserved_size, if non-zero, specifies the amount of bytes to 1523edcb4639STejun Heo * reserve after the static area in the first chunk. This reserves 1524edcb4639STejun Heo * the first chunk such that it's available only through reserved 1525edcb4639STejun Heo * percpu allocation. This is primarily used to serve module percpu 1526edcb4639STejun Heo * static areas on architectures where the addressing model has 1527edcb4639STejun Heo * limited offset range for symbol relocations to guarantee module 1528edcb4639STejun Heo * percpu symbols fall inside the relocatable range. 1529edcb4639STejun Heo * 1530fd1e8a1fSTejun Heo * @ai->dyn_size determines the number of bytes available for dynamic 1531fd1e8a1fSTejun Heo * allocation in the first chunk. The area between @ai->static_size + 1532fd1e8a1fSTejun Heo * @ai->reserved_size + @ai->dyn_size and @ai->unit_size is unused. 15336074d5b0STejun Heo * 1534fd1e8a1fSTejun Heo * @ai->unit_size specifies unit size and must be aligned to PAGE_SIZE 1535fd1e8a1fSTejun Heo * and equal to or larger than @ai->static_size + @ai->reserved_size + 1536fd1e8a1fSTejun Heo * @ai->dyn_size. 15378d408b4bSTejun Heo * 1538fd1e8a1fSTejun Heo * @ai->atom_size is the allocation atom size and used as alignment 1539fd1e8a1fSTejun Heo * for vm areas. 15408d408b4bSTejun Heo * 1541fd1e8a1fSTejun Heo * @ai->alloc_size is the allocation size and always multiple of 1542fd1e8a1fSTejun Heo * @ai->atom_size. This is larger than @ai->atom_size if 1543fd1e8a1fSTejun Heo * @ai->unit_size is larger than @ai->atom_size. 1544fd1e8a1fSTejun Heo * 1545fd1e8a1fSTejun Heo * @ai->nr_groups and @ai->groups describe virtual memory layout of 1546fd1e8a1fSTejun Heo * percpu areas. Units which should be colocated are put into the 1547fd1e8a1fSTejun Heo * same group. Dynamic VM areas will be allocated according to these 1548fd1e8a1fSTejun Heo * groupings. If @ai->nr_groups is zero, a single group containing 1549fd1e8a1fSTejun Heo * all units is assumed. 15508d408b4bSTejun Heo * 155138a6be52STejun Heo * The caller should have mapped the first chunk at @base_addr and 155238a6be52STejun Heo * copied static data to each unit. 1553fbf59bc9STejun Heo * 1554edcb4639STejun Heo * If the first chunk ends up with both reserved and dynamic areas, it 1555edcb4639STejun Heo * is served by two chunks - one to serve the core static and reserved 1556edcb4639STejun Heo * areas and the other for the dynamic area. They share the same vm 1557edcb4639STejun Heo * and page map but uses different area allocation map to stay away 1558edcb4639STejun Heo * from each other. The latter chunk is circulated in the chunk slots 1559edcb4639STejun Heo * and available for dynamic allocation like any other chunks. 1560edcb4639STejun Heo * 1561fbf59bc9STejun Heo * RETURNS: 1562fb435d52STejun Heo * 0 on success, -errno on failure. 1563fbf59bc9STejun Heo */ 1564fb435d52STejun Heo int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, 1565fd1e8a1fSTejun Heo void *base_addr) 1566fbf59bc9STejun Heo { 1567099a19d9STejun Heo static int smap[PERCPU_DYNAMIC_EARLY_SLOTS] __initdata; 1568099a19d9STejun Heo static int dmap[PERCPU_DYNAMIC_EARLY_SLOTS] __initdata; 1569fd1e8a1fSTejun Heo size_t dyn_size = ai->dyn_size; 1570fd1e8a1fSTejun Heo size_t size_sum = ai->static_size + ai->reserved_size + dyn_size; 1571edcb4639STejun Heo struct pcpu_chunk *schunk, *dchunk = NULL; 15726563297cSTejun Heo unsigned long *group_offsets; 15736563297cSTejun Heo size_t *group_sizes; 1574fb435d52STejun Heo unsigned long *unit_off; 1575fbf59bc9STejun Heo unsigned int cpu; 1576fd1e8a1fSTejun Heo int *unit_map; 1577fd1e8a1fSTejun Heo int group, unit, i; 1578fbf59bc9STejun Heo 1579635b75fcSTejun Heo #define PCPU_SETUP_BUG_ON(cond) do { \ 1580635b75fcSTejun Heo if (unlikely(cond)) { \ 1581870d4b12SJoe Perches pr_emerg("failed to initialize, %s\n", #cond); \ 1582870d4b12SJoe Perches pr_emerg("cpu_possible_mask=%*pb\n", \ 1583807de073STejun Heo cpumask_pr_args(cpu_possible_mask)); \ 1584635b75fcSTejun Heo pcpu_dump_alloc_info(KERN_EMERG, ai); \ 1585635b75fcSTejun Heo BUG(); \ 1586635b75fcSTejun Heo } \ 1587635b75fcSTejun Heo } while (0) 1588635b75fcSTejun Heo 15892f39e637STejun Heo /* sanity checks */ 1590635b75fcSTejun Heo PCPU_SETUP_BUG_ON(ai->nr_groups <= 0); 1591bbddff05STejun Heo #ifdef CONFIG_SMP 1592635b75fcSTejun Heo PCPU_SETUP_BUG_ON(!ai->static_size); 1593f09f1243SAlexander Kuleshov PCPU_SETUP_BUG_ON(offset_in_page(__per_cpu_start)); 1594bbddff05STejun Heo #endif 1595635b75fcSTejun Heo PCPU_SETUP_BUG_ON(!base_addr); 1596f09f1243SAlexander Kuleshov PCPU_SETUP_BUG_ON(offset_in_page(base_addr)); 1597635b75fcSTejun Heo PCPU_SETUP_BUG_ON(ai->unit_size < size_sum); 1598f09f1243SAlexander Kuleshov PCPU_SETUP_BUG_ON(offset_in_page(ai->unit_size)); 1599635b75fcSTejun Heo PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE); 1600099a19d9STejun Heo PCPU_SETUP_BUG_ON(ai->dyn_size < PERCPU_DYNAMIC_EARLY_SIZE); 16019f645532STejun Heo PCPU_SETUP_BUG_ON(pcpu_verify_alloc_info(ai) < 0); 16028d408b4bSTejun Heo 16036563297cSTejun Heo /* process group information and build config tables accordingly */ 1604999c17e3SSantosh Shilimkar group_offsets = memblock_virt_alloc(ai->nr_groups * 1605999c17e3SSantosh Shilimkar sizeof(group_offsets[0]), 0); 1606999c17e3SSantosh Shilimkar group_sizes = memblock_virt_alloc(ai->nr_groups * 1607999c17e3SSantosh Shilimkar sizeof(group_sizes[0]), 0); 1608999c17e3SSantosh Shilimkar unit_map = memblock_virt_alloc(nr_cpu_ids * sizeof(unit_map[0]), 0); 1609999c17e3SSantosh Shilimkar unit_off = memblock_virt_alloc(nr_cpu_ids * sizeof(unit_off[0]), 0); 16102f39e637STejun Heo 1611fd1e8a1fSTejun Heo for (cpu = 0; cpu < nr_cpu_ids; cpu++) 1612ffe0d5a5STejun Heo unit_map[cpu] = UINT_MAX; 1613a855b84cSTejun Heo 1614a855b84cSTejun Heo pcpu_low_unit_cpu = NR_CPUS; 1615a855b84cSTejun Heo pcpu_high_unit_cpu = NR_CPUS; 16162f39e637STejun Heo 1617fd1e8a1fSTejun Heo for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) { 1618fd1e8a1fSTejun Heo const struct pcpu_group_info *gi = &ai->groups[group]; 16192f39e637STejun Heo 16206563297cSTejun Heo group_offsets[group] = gi->base_offset; 16216563297cSTejun Heo group_sizes[group] = gi->nr_units * ai->unit_size; 16226563297cSTejun Heo 1623fd1e8a1fSTejun Heo for (i = 0; i < gi->nr_units; i++) { 1624fd1e8a1fSTejun Heo cpu = gi->cpu_map[i]; 1625fd1e8a1fSTejun Heo if (cpu == NR_CPUS) 1626fd1e8a1fSTejun Heo continue; 1627fd1e8a1fSTejun Heo 16289f295664SDan Carpenter PCPU_SETUP_BUG_ON(cpu >= nr_cpu_ids); 1629635b75fcSTejun Heo PCPU_SETUP_BUG_ON(!cpu_possible(cpu)); 1630635b75fcSTejun Heo PCPU_SETUP_BUG_ON(unit_map[cpu] != UINT_MAX); 1631fd1e8a1fSTejun Heo 1632fd1e8a1fSTejun Heo unit_map[cpu] = unit + i; 1633fb435d52STejun Heo unit_off[cpu] = gi->base_offset + i * ai->unit_size; 1634fb435d52STejun Heo 1635a855b84cSTejun Heo /* determine low/high unit_cpu */ 1636a855b84cSTejun Heo if (pcpu_low_unit_cpu == NR_CPUS || 1637a855b84cSTejun Heo unit_off[cpu] < unit_off[pcpu_low_unit_cpu]) 1638a855b84cSTejun Heo pcpu_low_unit_cpu = cpu; 1639a855b84cSTejun Heo if (pcpu_high_unit_cpu == NR_CPUS || 1640a855b84cSTejun Heo unit_off[cpu] > unit_off[pcpu_high_unit_cpu]) 1641a855b84cSTejun Heo pcpu_high_unit_cpu = cpu; 16420fc0531eSLinus Torvalds } 16430fc0531eSLinus Torvalds } 1644fd1e8a1fSTejun Heo pcpu_nr_units = unit; 16452f39e637STejun Heo 16462f39e637STejun Heo for_each_possible_cpu(cpu) 1647635b75fcSTejun Heo PCPU_SETUP_BUG_ON(unit_map[cpu] == UINT_MAX); 1648635b75fcSTejun Heo 1649635b75fcSTejun Heo /* we're done parsing the input, undefine BUG macro and dump config */ 1650635b75fcSTejun Heo #undef PCPU_SETUP_BUG_ON 1651bcbea798STejun Heo pcpu_dump_alloc_info(KERN_DEBUG, ai); 16522f39e637STejun Heo 16536563297cSTejun Heo pcpu_nr_groups = ai->nr_groups; 16546563297cSTejun Heo pcpu_group_offsets = group_offsets; 16556563297cSTejun Heo pcpu_group_sizes = group_sizes; 1656fd1e8a1fSTejun Heo pcpu_unit_map = unit_map; 1657fb435d52STejun Heo pcpu_unit_offsets = unit_off; 16582f39e637STejun Heo 16592f39e637STejun Heo /* determine basic parameters */ 1660fd1e8a1fSTejun Heo pcpu_unit_pages = ai->unit_size >> PAGE_SHIFT; 1661d9b55eebSTejun Heo pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT; 16626563297cSTejun Heo pcpu_atom_size = ai->atom_size; 1663ce3141a2STejun Heo pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) + 1664ce3141a2STejun Heo BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long); 1665cafe8816STejun Heo 166630a5b536SDennis Zhou pcpu_stats_save_ai(ai); 166730a5b536SDennis Zhou 1668d9b55eebSTejun Heo /* 1669d9b55eebSTejun Heo * Allocate chunk slots. The additional last slot is for 1670d9b55eebSTejun Heo * empty chunks. 1671d9b55eebSTejun Heo */ 1672d9b55eebSTejun Heo pcpu_nr_slots = __pcpu_size_to_slot(pcpu_unit_size) + 2; 1673999c17e3SSantosh Shilimkar pcpu_slot = memblock_virt_alloc( 1674999c17e3SSantosh Shilimkar pcpu_nr_slots * sizeof(pcpu_slot[0]), 0); 1675fbf59bc9STejun Heo for (i = 0; i < pcpu_nr_slots; i++) 1676fbf59bc9STejun Heo INIT_LIST_HEAD(&pcpu_slot[i]); 1677fbf59bc9STejun Heo 1678edcb4639STejun Heo /* 1679edcb4639STejun Heo * Initialize static chunk. If reserved_size is zero, the 1680edcb4639STejun Heo * static chunk covers static area + dynamic allocation area 1681edcb4639STejun Heo * in the first chunk. If reserved_size is not zero, it 1682edcb4639STejun Heo * covers static area + reserved area (mostly used for module 1683edcb4639STejun Heo * static percpu allocation). 1684edcb4639STejun Heo */ 1685999c17e3SSantosh Shilimkar schunk = memblock_virt_alloc(pcpu_chunk_struct_size, 0); 16862441d15cSTejun Heo INIT_LIST_HEAD(&schunk->list); 16874f996e23STejun Heo INIT_LIST_HEAD(&schunk->map_extend_list); 1688bba174f5STejun Heo schunk->base_addr = base_addr; 168961ace7faSTejun Heo schunk->map = smap; 169061ace7faSTejun Heo schunk->map_alloc = ARRAY_SIZE(smap); 169138a6be52STejun Heo schunk->immutable = true; 1692ce3141a2STejun Heo bitmap_fill(schunk->populated, pcpu_unit_pages); 1693b539b87fSTejun Heo schunk->nr_populated = pcpu_unit_pages; 1694edcb4639STejun Heo 1695fd1e8a1fSTejun Heo if (ai->reserved_size) { 1696fd1e8a1fSTejun Heo schunk->free_size = ai->reserved_size; 1697ae9e6bc9STejun Heo pcpu_reserved_chunk = schunk; 1698fd1e8a1fSTejun Heo pcpu_reserved_chunk_limit = ai->static_size + ai->reserved_size; 1699edcb4639STejun Heo } else { 17002441d15cSTejun Heo schunk->free_size = dyn_size; 1701edcb4639STejun Heo dyn_size = 0; /* dynamic area covered */ 1702edcb4639STejun Heo } 17032441d15cSTejun Heo schunk->contig_hint = schunk->free_size; 1704fbf59bc9STejun Heo 1705723ad1d9SAl Viro schunk->map[0] = 1; 1706723ad1d9SAl Viro schunk->map[1] = ai->static_size; 1707723ad1d9SAl Viro schunk->map_used = 1; 170861ace7faSTejun Heo if (schunk->free_size) 1709292c24a0SBaoquan He schunk->map[++schunk->map_used] = ai->static_size + schunk->free_size; 1710292c24a0SBaoquan He schunk->map[schunk->map_used] |= 1; 171130a5b536SDennis Zhou schunk->has_reserved = true; 171261ace7faSTejun Heo 1713edcb4639STejun Heo /* init dynamic chunk if necessary */ 1714edcb4639STejun Heo if (dyn_size) { 1715999c17e3SSantosh Shilimkar dchunk = memblock_virt_alloc(pcpu_chunk_struct_size, 0); 1716edcb4639STejun Heo INIT_LIST_HEAD(&dchunk->list); 17174f996e23STejun Heo INIT_LIST_HEAD(&dchunk->map_extend_list); 1718bba174f5STejun Heo dchunk->base_addr = base_addr; 1719edcb4639STejun Heo dchunk->map = dmap; 1720edcb4639STejun Heo dchunk->map_alloc = ARRAY_SIZE(dmap); 172138a6be52STejun Heo dchunk->immutable = true; 1722ce3141a2STejun Heo bitmap_fill(dchunk->populated, pcpu_unit_pages); 1723b539b87fSTejun Heo dchunk->nr_populated = pcpu_unit_pages; 1724edcb4639STejun Heo 1725edcb4639STejun Heo dchunk->contig_hint = dchunk->free_size = dyn_size; 1726723ad1d9SAl Viro dchunk->map[0] = 1; 1727723ad1d9SAl Viro dchunk->map[1] = pcpu_reserved_chunk_limit; 1728723ad1d9SAl Viro dchunk->map[2] = (pcpu_reserved_chunk_limit + dchunk->free_size) | 1; 1729723ad1d9SAl Viro dchunk->map_used = 2; 173030a5b536SDennis Zhou dchunk->has_reserved = true; 1731edcb4639STejun Heo } 1732edcb4639STejun Heo 17332441d15cSTejun Heo /* link the first chunk in */ 1734ae9e6bc9STejun Heo pcpu_first_chunk = dchunk ?: schunk; 1735b539b87fSTejun Heo pcpu_nr_empty_pop_pages += 1736b539b87fSTejun Heo pcpu_count_occupied_pages(pcpu_first_chunk, 1); 1737ae9e6bc9STejun Heo pcpu_chunk_relocate(pcpu_first_chunk, -1); 1738fbf59bc9STejun Heo 173930a5b536SDennis Zhou pcpu_stats_chunk_alloc(); 1740df95e795SDennis Zhou trace_percpu_create_chunk(base_addr); 174130a5b536SDennis Zhou 1742fbf59bc9STejun Heo /* we're done */ 1743bba174f5STejun Heo pcpu_base_addr = base_addr; 1744fb435d52STejun Heo return 0; 1745fbf59bc9STejun Heo } 174666c3a757STejun Heo 1747bbddff05STejun Heo #ifdef CONFIG_SMP 1748bbddff05STejun Heo 174917f3609cSAndi Kleen const char * const pcpu_fc_names[PCPU_FC_NR] __initconst = { 1750f58dc01bSTejun Heo [PCPU_FC_AUTO] = "auto", 1751f58dc01bSTejun Heo [PCPU_FC_EMBED] = "embed", 1752f58dc01bSTejun Heo [PCPU_FC_PAGE] = "page", 1753f58dc01bSTejun Heo }; 175466c3a757STejun Heo 1755f58dc01bSTejun Heo enum pcpu_fc pcpu_chosen_fc __initdata = PCPU_FC_AUTO; 1756f58dc01bSTejun Heo 1757f58dc01bSTejun Heo static int __init percpu_alloc_setup(char *str) 175866c3a757STejun Heo { 17595479c78aSCyrill Gorcunov if (!str) 17605479c78aSCyrill Gorcunov return -EINVAL; 17615479c78aSCyrill Gorcunov 1762f58dc01bSTejun Heo if (0) 1763f58dc01bSTejun Heo /* nada */; 1764f58dc01bSTejun Heo #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK 1765f58dc01bSTejun Heo else if (!strcmp(str, "embed")) 1766f58dc01bSTejun Heo pcpu_chosen_fc = PCPU_FC_EMBED; 1767f58dc01bSTejun Heo #endif 1768f58dc01bSTejun Heo #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK 1769f58dc01bSTejun Heo else if (!strcmp(str, "page")) 1770f58dc01bSTejun Heo pcpu_chosen_fc = PCPU_FC_PAGE; 1771f58dc01bSTejun Heo #endif 1772f58dc01bSTejun Heo else 1773870d4b12SJoe Perches pr_warn("unknown allocator %s specified\n", str); 177466c3a757STejun Heo 1775f58dc01bSTejun Heo return 0; 177666c3a757STejun Heo } 1777f58dc01bSTejun Heo early_param("percpu_alloc", percpu_alloc_setup); 177866c3a757STejun Heo 17793c9a024fSTejun Heo /* 17803c9a024fSTejun Heo * pcpu_embed_first_chunk() is used by the generic percpu setup. 17813c9a024fSTejun Heo * Build it if needed by the arch config or the generic setup is going 17823c9a024fSTejun Heo * to be used. 17833c9a024fSTejun Heo */ 178408fc4580STejun Heo #if defined(CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK) || \ 178508fc4580STejun Heo !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) 17863c9a024fSTejun Heo #define BUILD_EMBED_FIRST_CHUNK 17873c9a024fSTejun Heo #endif 17883c9a024fSTejun Heo 17893c9a024fSTejun Heo /* build pcpu_page_first_chunk() iff needed by the arch config */ 17903c9a024fSTejun Heo #if defined(CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK) 17913c9a024fSTejun Heo #define BUILD_PAGE_FIRST_CHUNK 17923c9a024fSTejun Heo #endif 17933c9a024fSTejun Heo 17943c9a024fSTejun Heo /* pcpu_build_alloc_info() is used by both embed and page first chunk */ 17953c9a024fSTejun Heo #if defined(BUILD_EMBED_FIRST_CHUNK) || defined(BUILD_PAGE_FIRST_CHUNK) 17963c9a024fSTejun Heo /** 1797fbf59bc9STejun Heo * pcpu_build_alloc_info - build alloc_info considering distances between CPUs 1798fbf59bc9STejun Heo * @reserved_size: the size of reserved percpu area in bytes 1799fbf59bc9STejun Heo * @dyn_size: minimum free size for dynamic allocation in bytes 1800fbf59bc9STejun Heo * @atom_size: allocation atom size 1801fbf59bc9STejun Heo * @cpu_distance_fn: callback to determine distance between cpus, optional 1802fbf59bc9STejun Heo * 1803fbf59bc9STejun Heo * This function determines grouping of units, their mappings to cpus 1804fbf59bc9STejun Heo * and other parameters considering needed percpu size, allocation 1805fbf59bc9STejun Heo * atom size and distances between CPUs. 1806fbf59bc9STejun Heo * 1807bffc4375SYannick Guerrini * Groups are always multiples of atom size and CPUs which are of 1808fbf59bc9STejun Heo * LOCAL_DISTANCE both ways are grouped together and share space for 1809fbf59bc9STejun Heo * units in the same group. The returned configuration is guaranteed 1810fbf59bc9STejun Heo * to have CPUs on different nodes on different groups and >=75% usage 1811fbf59bc9STejun Heo * of allocated virtual address space. 1812fbf59bc9STejun Heo * 1813fbf59bc9STejun Heo * RETURNS: 1814fbf59bc9STejun Heo * On success, pointer to the new allocation_info is returned. On 1815fbf59bc9STejun Heo * failure, ERR_PTR value is returned. 1816fbf59bc9STejun Heo */ 1817fbf59bc9STejun Heo static struct pcpu_alloc_info * __init pcpu_build_alloc_info( 1818fbf59bc9STejun Heo size_t reserved_size, size_t dyn_size, 1819fbf59bc9STejun Heo size_t atom_size, 1820fbf59bc9STejun Heo pcpu_fc_cpu_distance_fn_t cpu_distance_fn) 1821fbf59bc9STejun Heo { 1822fbf59bc9STejun Heo static int group_map[NR_CPUS] __initdata; 1823fbf59bc9STejun Heo static int group_cnt[NR_CPUS] __initdata; 1824fbf59bc9STejun Heo const size_t static_size = __per_cpu_end - __per_cpu_start; 1825fbf59bc9STejun Heo int nr_groups = 1, nr_units = 0; 1826fbf59bc9STejun Heo size_t size_sum, min_unit_size, alloc_size; 1827fbf59bc9STejun Heo int upa, max_upa, uninitialized_var(best_upa); /* units_per_alloc */ 1828fbf59bc9STejun Heo int last_allocs, group, unit; 1829fbf59bc9STejun Heo unsigned int cpu, tcpu; 1830fbf59bc9STejun Heo struct pcpu_alloc_info *ai; 1831fbf59bc9STejun Heo unsigned int *cpu_map; 1832fbf59bc9STejun Heo 1833fbf59bc9STejun Heo /* this function may be called multiple times */ 1834fbf59bc9STejun Heo memset(group_map, 0, sizeof(group_map)); 1835fbf59bc9STejun Heo memset(group_cnt, 0, sizeof(group_cnt)); 1836fbf59bc9STejun Heo 1837fbf59bc9STejun Heo /* calculate size_sum and ensure dyn_size is enough for early alloc */ 1838fbf59bc9STejun Heo size_sum = PFN_ALIGN(static_size + reserved_size + 1839fbf59bc9STejun Heo max_t(size_t, dyn_size, PERCPU_DYNAMIC_EARLY_SIZE)); 1840fbf59bc9STejun Heo dyn_size = size_sum - static_size - reserved_size; 1841fbf59bc9STejun Heo 1842fbf59bc9STejun Heo /* 1843fbf59bc9STejun Heo * Determine min_unit_size, alloc_size and max_upa such that 1844fbf59bc9STejun Heo * alloc_size is multiple of atom_size and is the smallest 184525985edcSLucas De Marchi * which can accommodate 4k aligned segments which are equal to 1846fbf59bc9STejun Heo * or larger than min_unit_size. 1847fbf59bc9STejun Heo */ 1848fbf59bc9STejun Heo min_unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE); 1849fbf59bc9STejun Heo 1850*9c015162SDennis Zhou (Facebook) /* determine the maximum # of units that can fit in an allocation */ 1851fbf59bc9STejun Heo alloc_size = roundup(min_unit_size, atom_size); 1852fbf59bc9STejun Heo upa = alloc_size / min_unit_size; 1853f09f1243SAlexander Kuleshov while (alloc_size % upa || (offset_in_page(alloc_size / upa))) 1854fbf59bc9STejun Heo upa--; 1855fbf59bc9STejun Heo max_upa = upa; 1856fbf59bc9STejun Heo 1857fbf59bc9STejun Heo /* group cpus according to their proximity */ 1858fbf59bc9STejun Heo for_each_possible_cpu(cpu) { 1859fbf59bc9STejun Heo group = 0; 1860fbf59bc9STejun Heo next_group: 1861fbf59bc9STejun Heo for_each_possible_cpu(tcpu) { 1862fbf59bc9STejun Heo if (cpu == tcpu) 1863fbf59bc9STejun Heo break; 1864fbf59bc9STejun Heo if (group_map[tcpu] == group && cpu_distance_fn && 1865fbf59bc9STejun Heo (cpu_distance_fn(cpu, tcpu) > LOCAL_DISTANCE || 1866fbf59bc9STejun Heo cpu_distance_fn(tcpu, cpu) > LOCAL_DISTANCE)) { 1867fbf59bc9STejun Heo group++; 1868fbf59bc9STejun Heo nr_groups = max(nr_groups, group + 1); 1869fbf59bc9STejun Heo goto next_group; 1870fbf59bc9STejun Heo } 1871fbf59bc9STejun Heo } 1872fbf59bc9STejun Heo group_map[cpu] = group; 1873fbf59bc9STejun Heo group_cnt[group]++; 1874fbf59bc9STejun Heo } 1875fbf59bc9STejun Heo 1876fbf59bc9STejun Heo /* 1877*9c015162SDennis Zhou (Facebook) * Wasted space is caused by a ratio imbalance of upa to group_cnt. 1878*9c015162SDennis Zhou (Facebook) * Expand the unit_size until we use >= 75% of the units allocated. 1879*9c015162SDennis Zhou (Facebook) * Related to atom_size, which could be much larger than the unit_size. 1880fbf59bc9STejun Heo */ 1881fbf59bc9STejun Heo last_allocs = INT_MAX; 1882fbf59bc9STejun Heo for (upa = max_upa; upa; upa--) { 1883fbf59bc9STejun Heo int allocs = 0, wasted = 0; 1884fbf59bc9STejun Heo 1885f09f1243SAlexander Kuleshov if (alloc_size % upa || (offset_in_page(alloc_size / upa))) 1886fbf59bc9STejun Heo continue; 1887fbf59bc9STejun Heo 1888fbf59bc9STejun Heo for (group = 0; group < nr_groups; group++) { 1889fbf59bc9STejun Heo int this_allocs = DIV_ROUND_UP(group_cnt[group], upa); 1890fbf59bc9STejun Heo allocs += this_allocs; 1891fbf59bc9STejun Heo wasted += this_allocs * upa - group_cnt[group]; 1892fbf59bc9STejun Heo } 1893fbf59bc9STejun Heo 1894fbf59bc9STejun Heo /* 1895fbf59bc9STejun Heo * Don't accept if wastage is over 1/3. The 1896fbf59bc9STejun Heo * greater-than comparison ensures upa==1 always 1897fbf59bc9STejun Heo * passes the following check. 1898fbf59bc9STejun Heo */ 1899fbf59bc9STejun Heo if (wasted > num_possible_cpus() / 3) 1900fbf59bc9STejun Heo continue; 1901fbf59bc9STejun Heo 1902fbf59bc9STejun Heo /* and then don't consume more memory */ 1903fbf59bc9STejun Heo if (allocs > last_allocs) 1904fbf59bc9STejun Heo break; 1905fbf59bc9STejun Heo last_allocs = allocs; 1906fbf59bc9STejun Heo best_upa = upa; 1907fbf59bc9STejun Heo } 1908fbf59bc9STejun Heo upa = best_upa; 1909fbf59bc9STejun Heo 1910fbf59bc9STejun Heo /* allocate and fill alloc_info */ 1911fbf59bc9STejun Heo for (group = 0; group < nr_groups; group++) 1912fbf59bc9STejun Heo nr_units += roundup(group_cnt[group], upa); 1913fbf59bc9STejun Heo 1914fbf59bc9STejun Heo ai = pcpu_alloc_alloc_info(nr_groups, nr_units); 1915fbf59bc9STejun Heo if (!ai) 1916fbf59bc9STejun Heo return ERR_PTR(-ENOMEM); 1917fbf59bc9STejun Heo cpu_map = ai->groups[0].cpu_map; 1918fbf59bc9STejun Heo 1919fbf59bc9STejun Heo for (group = 0; group < nr_groups; group++) { 1920fbf59bc9STejun Heo ai->groups[group].cpu_map = cpu_map; 1921fbf59bc9STejun Heo cpu_map += roundup(group_cnt[group], upa); 1922fbf59bc9STejun Heo } 1923fbf59bc9STejun Heo 1924fbf59bc9STejun Heo ai->static_size = static_size; 1925fbf59bc9STejun Heo ai->reserved_size = reserved_size; 1926fbf59bc9STejun Heo ai->dyn_size = dyn_size; 1927fbf59bc9STejun Heo ai->unit_size = alloc_size / upa; 1928fbf59bc9STejun Heo ai->atom_size = atom_size; 1929fbf59bc9STejun Heo ai->alloc_size = alloc_size; 1930fbf59bc9STejun Heo 1931fbf59bc9STejun Heo for (group = 0, unit = 0; group_cnt[group]; group++) { 1932fbf59bc9STejun Heo struct pcpu_group_info *gi = &ai->groups[group]; 1933fbf59bc9STejun Heo 1934fbf59bc9STejun Heo /* 1935fbf59bc9STejun Heo * Initialize base_offset as if all groups are located 1936fbf59bc9STejun Heo * back-to-back. The caller should update this to 1937fbf59bc9STejun Heo * reflect actual allocation. 1938fbf59bc9STejun Heo */ 1939fbf59bc9STejun Heo gi->base_offset = unit * ai->unit_size; 1940fbf59bc9STejun Heo 1941fbf59bc9STejun Heo for_each_possible_cpu(cpu) 1942fbf59bc9STejun Heo if (group_map[cpu] == group) 1943fbf59bc9STejun Heo gi->cpu_map[gi->nr_units++] = cpu; 1944fbf59bc9STejun Heo gi->nr_units = roundup(gi->nr_units, upa); 1945fbf59bc9STejun Heo unit += gi->nr_units; 1946fbf59bc9STejun Heo } 1947fbf59bc9STejun Heo BUG_ON(unit != nr_units); 1948fbf59bc9STejun Heo 1949fbf59bc9STejun Heo return ai; 1950fbf59bc9STejun Heo } 19513c9a024fSTejun Heo #endif /* BUILD_EMBED_FIRST_CHUNK || BUILD_PAGE_FIRST_CHUNK */ 1952fbf59bc9STejun Heo 19533c9a024fSTejun Heo #if defined(BUILD_EMBED_FIRST_CHUNK) 195466c3a757STejun Heo /** 195566c3a757STejun Heo * pcpu_embed_first_chunk - embed the first percpu chunk into bootmem 195666c3a757STejun Heo * @reserved_size: the size of reserved percpu area in bytes 19574ba6ce25STejun Heo * @dyn_size: minimum free size for dynamic allocation in bytes 1958c8826dd5STejun Heo * @atom_size: allocation atom size 1959c8826dd5STejun Heo * @cpu_distance_fn: callback to determine distance between cpus, optional 1960c8826dd5STejun Heo * @alloc_fn: function to allocate percpu page 196125985edcSLucas De Marchi * @free_fn: function to free percpu page 196266c3a757STejun Heo * 196366c3a757STejun Heo * This is a helper to ease setting up embedded first percpu chunk and 196466c3a757STejun Heo * can be called where pcpu_setup_first_chunk() is expected. 196566c3a757STejun Heo * 196666c3a757STejun Heo * If this function is used to setup the first chunk, it is allocated 1967c8826dd5STejun Heo * by calling @alloc_fn and used as-is without being mapped into 1968c8826dd5STejun Heo * vmalloc area. Allocations are always whole multiples of @atom_size 1969c8826dd5STejun Heo * aligned to @atom_size. 1970c8826dd5STejun Heo * 1971c8826dd5STejun Heo * This enables the first chunk to piggy back on the linear physical 1972c8826dd5STejun Heo * mapping which often uses larger page size. Please note that this 1973c8826dd5STejun Heo * can result in very sparse cpu->unit mapping on NUMA machines thus 1974c8826dd5STejun Heo * requiring large vmalloc address space. Don't use this allocator if 1975c8826dd5STejun Heo * vmalloc space is not orders of magnitude larger than distances 1976c8826dd5STejun Heo * between node memory addresses (ie. 32bit NUMA machines). 197766c3a757STejun Heo * 19784ba6ce25STejun Heo * @dyn_size specifies the minimum dynamic area size. 197966c3a757STejun Heo * 198066c3a757STejun Heo * If the needed size is smaller than the minimum or specified unit 1981c8826dd5STejun Heo * size, the leftover is returned using @free_fn. 198266c3a757STejun Heo * 198366c3a757STejun Heo * RETURNS: 1984fb435d52STejun Heo * 0 on success, -errno on failure. 198566c3a757STejun Heo */ 19864ba6ce25STejun Heo int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, 1987c8826dd5STejun Heo size_t atom_size, 1988c8826dd5STejun Heo pcpu_fc_cpu_distance_fn_t cpu_distance_fn, 1989c8826dd5STejun Heo pcpu_fc_alloc_fn_t alloc_fn, 1990c8826dd5STejun Heo pcpu_fc_free_fn_t free_fn) 199166c3a757STejun Heo { 1992c8826dd5STejun Heo void *base = (void *)ULONG_MAX; 1993c8826dd5STejun Heo void **areas = NULL; 1994fd1e8a1fSTejun Heo struct pcpu_alloc_info *ai; 199593c76b6bSzijun_hu size_t size_sum, areas_size; 199693c76b6bSzijun_hu unsigned long max_distance; 19979b739662Szijun_hu int group, i, highest_group, rc; 199866c3a757STejun Heo 1999c8826dd5STejun Heo ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size, 2000c8826dd5STejun Heo cpu_distance_fn); 2001fd1e8a1fSTejun Heo if (IS_ERR(ai)) 2002fd1e8a1fSTejun Heo return PTR_ERR(ai); 200366c3a757STejun Heo 2004fd1e8a1fSTejun Heo size_sum = ai->static_size + ai->reserved_size + ai->dyn_size; 2005c8826dd5STejun Heo areas_size = PFN_ALIGN(ai->nr_groups * sizeof(void *)); 200666c3a757STejun Heo 2007999c17e3SSantosh Shilimkar areas = memblock_virt_alloc_nopanic(areas_size, 0); 2008c8826dd5STejun Heo if (!areas) { 2009fb435d52STejun Heo rc = -ENOMEM; 2010c8826dd5STejun Heo goto out_free; 2011fa8a7094STejun Heo } 201266c3a757STejun Heo 20139b739662Szijun_hu /* allocate, copy and determine base address & max_distance */ 20149b739662Szijun_hu highest_group = 0; 2015c8826dd5STejun Heo for (group = 0; group < ai->nr_groups; group++) { 2016c8826dd5STejun Heo struct pcpu_group_info *gi = &ai->groups[group]; 2017c8826dd5STejun Heo unsigned int cpu = NR_CPUS; 2018c8826dd5STejun Heo void *ptr; 201966c3a757STejun Heo 2020c8826dd5STejun Heo for (i = 0; i < gi->nr_units && cpu == NR_CPUS; i++) 2021c8826dd5STejun Heo cpu = gi->cpu_map[i]; 2022c8826dd5STejun Heo BUG_ON(cpu == NR_CPUS); 2023c8826dd5STejun Heo 2024c8826dd5STejun Heo /* allocate space for the whole group */ 2025c8826dd5STejun Heo ptr = alloc_fn(cpu, gi->nr_units * ai->unit_size, atom_size); 2026c8826dd5STejun Heo if (!ptr) { 2027c8826dd5STejun Heo rc = -ENOMEM; 2028c8826dd5STejun Heo goto out_free_areas; 2029c8826dd5STejun Heo } 2030f528f0b8SCatalin Marinas /* kmemleak tracks the percpu allocations separately */ 2031f528f0b8SCatalin Marinas kmemleak_free(ptr); 2032c8826dd5STejun Heo areas[group] = ptr; 2033c8826dd5STejun Heo 2034c8826dd5STejun Heo base = min(ptr, base); 20359b739662Szijun_hu if (ptr > areas[highest_group]) 20369b739662Szijun_hu highest_group = group; 20379b739662Szijun_hu } 20389b739662Szijun_hu max_distance = areas[highest_group] - base; 20399b739662Szijun_hu max_distance += ai->unit_size * ai->groups[highest_group].nr_units; 20409b739662Szijun_hu 20419b739662Szijun_hu /* warn if maximum distance is further than 75% of vmalloc space */ 20429b739662Szijun_hu if (max_distance > VMALLOC_TOTAL * 3 / 4) { 20439b739662Szijun_hu pr_warn("max_distance=0x%lx too large for vmalloc space 0x%lx\n", 20449b739662Szijun_hu max_distance, VMALLOC_TOTAL); 20459b739662Szijun_hu #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK 20469b739662Szijun_hu /* and fail if we have fallback */ 20479b739662Szijun_hu rc = -EINVAL; 20489b739662Szijun_hu goto out_free_areas; 20499b739662Szijun_hu #endif 205042b64281STejun Heo } 205142b64281STejun Heo 205242b64281STejun Heo /* 205342b64281STejun Heo * Copy data and free unused parts. This should happen after all 205442b64281STejun Heo * allocations are complete; otherwise, we may end up with 205542b64281STejun Heo * overlapping groups. 205642b64281STejun Heo */ 205742b64281STejun Heo for (group = 0; group < ai->nr_groups; group++) { 205842b64281STejun Heo struct pcpu_group_info *gi = &ai->groups[group]; 205942b64281STejun Heo void *ptr = areas[group]; 2060c8826dd5STejun Heo 2061c8826dd5STejun Heo for (i = 0; i < gi->nr_units; i++, ptr += ai->unit_size) { 2062c8826dd5STejun Heo if (gi->cpu_map[i] == NR_CPUS) { 2063c8826dd5STejun Heo /* unused unit, free whole */ 2064c8826dd5STejun Heo free_fn(ptr, ai->unit_size); 2065c8826dd5STejun Heo continue; 2066c8826dd5STejun Heo } 2067c8826dd5STejun Heo /* copy and return the unused part */ 2068fd1e8a1fSTejun Heo memcpy(ptr, __per_cpu_load, ai->static_size); 2069c8826dd5STejun Heo free_fn(ptr + size_sum, ai->unit_size - size_sum); 2070c8826dd5STejun Heo } 207166c3a757STejun Heo } 207266c3a757STejun Heo 2073c8826dd5STejun Heo /* base address is now known, determine group base offsets */ 20746ea529a2STejun Heo for (group = 0; group < ai->nr_groups; group++) { 2075c8826dd5STejun Heo ai->groups[group].base_offset = areas[group] - base; 20766ea529a2STejun Heo } 2077c8826dd5STejun Heo 2078870d4b12SJoe Perches pr_info("Embedded %zu pages/cpu @%p s%zu r%zu d%zu u%zu\n", 2079fd1e8a1fSTejun Heo PFN_DOWN(size_sum), base, ai->static_size, ai->reserved_size, 2080fd1e8a1fSTejun Heo ai->dyn_size, ai->unit_size); 208166c3a757STejun Heo 2082fb435d52STejun Heo rc = pcpu_setup_first_chunk(ai, base); 2083c8826dd5STejun Heo goto out_free; 2084c8826dd5STejun Heo 2085c8826dd5STejun Heo out_free_areas: 2086c8826dd5STejun Heo for (group = 0; group < ai->nr_groups; group++) 2087f851c8d8SMichael Holzheu if (areas[group]) 2088c8826dd5STejun Heo free_fn(areas[group], 2089c8826dd5STejun Heo ai->groups[group].nr_units * ai->unit_size); 2090c8826dd5STejun Heo out_free: 2091fd1e8a1fSTejun Heo pcpu_free_alloc_info(ai); 2092c8826dd5STejun Heo if (areas) 2093999c17e3SSantosh Shilimkar memblock_free_early(__pa(areas), areas_size); 2094fb435d52STejun Heo return rc; 2095d4b95f80STejun Heo } 20963c9a024fSTejun Heo #endif /* BUILD_EMBED_FIRST_CHUNK */ 2097d4b95f80STejun Heo 20983c9a024fSTejun Heo #ifdef BUILD_PAGE_FIRST_CHUNK 2099d4b95f80STejun Heo /** 210000ae4064STejun Heo * pcpu_page_first_chunk - map the first chunk using PAGE_SIZE pages 2101d4b95f80STejun Heo * @reserved_size: the size of reserved percpu area in bytes 2102d4b95f80STejun Heo * @alloc_fn: function to allocate percpu page, always called with PAGE_SIZE 210325985edcSLucas De Marchi * @free_fn: function to free percpu page, always called with PAGE_SIZE 2104d4b95f80STejun Heo * @populate_pte_fn: function to populate pte 2105d4b95f80STejun Heo * 210600ae4064STejun Heo * This is a helper to ease setting up page-remapped first percpu 210700ae4064STejun Heo * chunk and can be called where pcpu_setup_first_chunk() is expected. 2108d4b95f80STejun Heo * 2109d4b95f80STejun Heo * This is the basic allocator. Static percpu area is allocated 2110d4b95f80STejun Heo * page-by-page into vmalloc area. 2111d4b95f80STejun Heo * 2112d4b95f80STejun Heo * RETURNS: 2113fb435d52STejun Heo * 0 on success, -errno on failure. 2114d4b95f80STejun Heo */ 2115fb435d52STejun Heo int __init pcpu_page_first_chunk(size_t reserved_size, 2116d4b95f80STejun Heo pcpu_fc_alloc_fn_t alloc_fn, 2117d4b95f80STejun Heo pcpu_fc_free_fn_t free_fn, 2118d4b95f80STejun Heo pcpu_fc_populate_pte_fn_t populate_pte_fn) 2119d4b95f80STejun Heo { 21208f05a6a6STejun Heo static struct vm_struct vm; 2121fd1e8a1fSTejun Heo struct pcpu_alloc_info *ai; 212200ae4064STejun Heo char psize_str[16]; 2123ce3141a2STejun Heo int unit_pages; 2124d4b95f80STejun Heo size_t pages_size; 2125ce3141a2STejun Heo struct page **pages; 2126fb435d52STejun Heo int unit, i, j, rc; 21278f606604Szijun_hu int upa; 21288f606604Szijun_hu int nr_g0_units; 2129d4b95f80STejun Heo 213000ae4064STejun Heo snprintf(psize_str, sizeof(psize_str), "%luK", PAGE_SIZE >> 10); 213100ae4064STejun Heo 21324ba6ce25STejun Heo ai = pcpu_build_alloc_info(reserved_size, 0, PAGE_SIZE, NULL); 2133fd1e8a1fSTejun Heo if (IS_ERR(ai)) 2134fd1e8a1fSTejun Heo return PTR_ERR(ai); 2135fd1e8a1fSTejun Heo BUG_ON(ai->nr_groups != 1); 21368f606604Szijun_hu upa = ai->alloc_size/ai->unit_size; 21378f606604Szijun_hu nr_g0_units = roundup(num_possible_cpus(), upa); 21388f606604Szijun_hu if (unlikely(WARN_ON(ai->groups[0].nr_units != nr_g0_units))) { 21398f606604Szijun_hu pcpu_free_alloc_info(ai); 21408f606604Szijun_hu return -EINVAL; 21418f606604Szijun_hu } 2142fd1e8a1fSTejun Heo 2143fd1e8a1fSTejun Heo unit_pages = ai->unit_size >> PAGE_SHIFT; 2144d4b95f80STejun Heo 2145d4b95f80STejun Heo /* unaligned allocations can't be freed, round up to page size */ 2146fd1e8a1fSTejun Heo pages_size = PFN_ALIGN(unit_pages * num_possible_cpus() * 2147fd1e8a1fSTejun Heo sizeof(pages[0])); 2148999c17e3SSantosh Shilimkar pages = memblock_virt_alloc(pages_size, 0); 2149d4b95f80STejun Heo 21508f05a6a6STejun Heo /* allocate pages */ 2151d4b95f80STejun Heo j = 0; 21528f606604Szijun_hu for (unit = 0; unit < num_possible_cpus(); unit++) { 2153fd1e8a1fSTejun Heo unsigned int cpu = ai->groups[0].cpu_map[unit]; 21548f606604Szijun_hu for (i = 0; i < unit_pages; i++) { 2155d4b95f80STejun Heo void *ptr; 2156d4b95f80STejun Heo 21573cbc8565STejun Heo ptr = alloc_fn(cpu, PAGE_SIZE, PAGE_SIZE); 2158d4b95f80STejun Heo if (!ptr) { 2159870d4b12SJoe Perches pr_warn("failed to allocate %s page for cpu%u\n", 2160598d8091SJoe Perches psize_str, cpu); 2161d4b95f80STejun Heo goto enomem; 2162d4b95f80STejun Heo } 2163f528f0b8SCatalin Marinas /* kmemleak tracks the percpu allocations separately */ 2164f528f0b8SCatalin Marinas kmemleak_free(ptr); 2165ce3141a2STejun Heo pages[j++] = virt_to_page(ptr); 2166d4b95f80STejun Heo } 21678f606604Szijun_hu } 2168d4b95f80STejun Heo 21698f05a6a6STejun Heo /* allocate vm area, map the pages and copy static data */ 21708f05a6a6STejun Heo vm.flags = VM_ALLOC; 2171fd1e8a1fSTejun Heo vm.size = num_possible_cpus() * ai->unit_size; 21728f05a6a6STejun Heo vm_area_register_early(&vm, PAGE_SIZE); 21738f05a6a6STejun Heo 2174fd1e8a1fSTejun Heo for (unit = 0; unit < num_possible_cpus(); unit++) { 21751d9d3257STejun Heo unsigned long unit_addr = 2176fd1e8a1fSTejun Heo (unsigned long)vm.addr + unit * ai->unit_size; 21778f05a6a6STejun Heo 2178ce3141a2STejun Heo for (i = 0; i < unit_pages; i++) 21798f05a6a6STejun Heo populate_pte_fn(unit_addr + (i << PAGE_SHIFT)); 21808f05a6a6STejun Heo 21818f05a6a6STejun Heo /* pte already populated, the following shouldn't fail */ 2182fb435d52STejun Heo rc = __pcpu_map_pages(unit_addr, &pages[unit * unit_pages], 2183ce3141a2STejun Heo unit_pages); 2184fb435d52STejun Heo if (rc < 0) 2185fb435d52STejun Heo panic("failed to map percpu area, err=%d\n", rc); 21868f05a6a6STejun Heo 21878f05a6a6STejun Heo /* 21888f05a6a6STejun Heo * FIXME: Archs with virtual cache should flush local 21898f05a6a6STejun Heo * cache for the linear mapping here - something 21908f05a6a6STejun Heo * equivalent to flush_cache_vmap() on the local cpu. 21918f05a6a6STejun Heo * flush_cache_vmap() can't be used as most supporting 21928f05a6a6STejun Heo * data structures are not set up yet. 21938f05a6a6STejun Heo */ 21948f05a6a6STejun Heo 21958f05a6a6STejun Heo /* copy static data */ 2196fd1e8a1fSTejun Heo memcpy((void *)unit_addr, __per_cpu_load, ai->static_size); 219766c3a757STejun Heo } 219866c3a757STejun Heo 219966c3a757STejun Heo /* we're ready, commit */ 2200870d4b12SJoe Perches pr_info("%d %s pages/cpu @%p s%zu r%zu d%zu\n", 2201fd1e8a1fSTejun Heo unit_pages, psize_str, vm.addr, ai->static_size, 2202fd1e8a1fSTejun Heo ai->reserved_size, ai->dyn_size); 220366c3a757STejun Heo 2204fb435d52STejun Heo rc = pcpu_setup_first_chunk(ai, vm.addr); 2205d4b95f80STejun Heo goto out_free_ar; 2206d4b95f80STejun Heo 2207d4b95f80STejun Heo enomem: 2208d4b95f80STejun Heo while (--j >= 0) 2209ce3141a2STejun Heo free_fn(page_address(pages[j]), PAGE_SIZE); 2210fb435d52STejun Heo rc = -ENOMEM; 2211d4b95f80STejun Heo out_free_ar: 2212999c17e3SSantosh Shilimkar memblock_free_early(__pa(pages), pages_size); 2213fd1e8a1fSTejun Heo pcpu_free_alloc_info(ai); 2214fb435d52STejun Heo return rc; 221566c3a757STejun Heo } 22163c9a024fSTejun Heo #endif /* BUILD_PAGE_FIRST_CHUNK */ 2217d4b95f80STejun Heo 2218bbddff05STejun Heo #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA 22198c4bfc6eSTejun Heo /* 2220bbddff05STejun Heo * Generic SMP percpu area setup. 2221e74e3962STejun Heo * 2222e74e3962STejun Heo * The embedding helper is used because its behavior closely resembles 2223e74e3962STejun Heo * the original non-dynamic generic percpu area setup. This is 2224e74e3962STejun Heo * important because many archs have addressing restrictions and might 2225e74e3962STejun Heo * fail if the percpu area is located far away from the previous 2226e74e3962STejun Heo * location. As an added bonus, in non-NUMA cases, embedding is 2227e74e3962STejun Heo * generally a good idea TLB-wise because percpu area can piggy back 2228e74e3962STejun Heo * on the physical linear memory mapping which uses large page 2229e74e3962STejun Heo * mappings on applicable archs. 2230e74e3962STejun Heo */ 2231e74e3962STejun Heo unsigned long __per_cpu_offset[NR_CPUS] __read_mostly; 2232e74e3962STejun Heo EXPORT_SYMBOL(__per_cpu_offset); 2233e74e3962STejun Heo 2234c8826dd5STejun Heo static void * __init pcpu_dfl_fc_alloc(unsigned int cpu, size_t size, 2235c8826dd5STejun Heo size_t align) 2236c8826dd5STejun Heo { 2237999c17e3SSantosh Shilimkar return memblock_virt_alloc_from_nopanic( 2238999c17e3SSantosh Shilimkar size, align, __pa(MAX_DMA_ADDRESS)); 2239c8826dd5STejun Heo } 2240c8826dd5STejun Heo 2241c8826dd5STejun Heo static void __init pcpu_dfl_fc_free(void *ptr, size_t size) 2242c8826dd5STejun Heo { 2243999c17e3SSantosh Shilimkar memblock_free_early(__pa(ptr), size); 2244c8826dd5STejun Heo } 2245c8826dd5STejun Heo 2246e74e3962STejun Heo void __init setup_per_cpu_areas(void) 2247e74e3962STejun Heo { 2248e74e3962STejun Heo unsigned long delta; 2249e74e3962STejun Heo unsigned int cpu; 2250fb435d52STejun Heo int rc; 2251e74e3962STejun Heo 2252e74e3962STejun Heo /* 2253e74e3962STejun Heo * Always reserve area for module percpu variables. That's 2254e74e3962STejun Heo * what the legacy allocator did. 2255e74e3962STejun Heo */ 2256fb435d52STejun Heo rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, 2257c8826dd5STejun Heo PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, NULL, 2258c8826dd5STejun Heo pcpu_dfl_fc_alloc, pcpu_dfl_fc_free); 2259fb435d52STejun Heo if (rc < 0) 2260bbddff05STejun Heo panic("Failed to initialize percpu areas."); 2261e74e3962STejun Heo 2262e74e3962STejun Heo delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; 2263e74e3962STejun Heo for_each_possible_cpu(cpu) 2264fb435d52STejun Heo __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu]; 2265e74e3962STejun Heo } 2266e74e3962STejun Heo #endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */ 2267099a19d9STejun Heo 2268bbddff05STejun Heo #else /* CONFIG_SMP */ 2269bbddff05STejun Heo 2270bbddff05STejun Heo /* 2271bbddff05STejun Heo * UP percpu area setup. 2272bbddff05STejun Heo * 2273bbddff05STejun Heo * UP always uses km-based percpu allocator with identity mapping. 2274bbddff05STejun Heo * Static percpu variables are indistinguishable from the usual static 2275bbddff05STejun Heo * variables and don't require any special preparation. 2276bbddff05STejun Heo */ 2277bbddff05STejun Heo void __init setup_per_cpu_areas(void) 2278bbddff05STejun Heo { 2279bbddff05STejun Heo const size_t unit_size = 2280bbddff05STejun Heo roundup_pow_of_two(max_t(size_t, PCPU_MIN_UNIT_SIZE, 2281bbddff05STejun Heo PERCPU_DYNAMIC_RESERVE)); 2282bbddff05STejun Heo struct pcpu_alloc_info *ai; 2283bbddff05STejun Heo void *fc; 2284bbddff05STejun Heo 2285bbddff05STejun Heo ai = pcpu_alloc_alloc_info(1, 1); 2286999c17e3SSantosh Shilimkar fc = memblock_virt_alloc_from_nopanic(unit_size, 2287999c17e3SSantosh Shilimkar PAGE_SIZE, 2288999c17e3SSantosh Shilimkar __pa(MAX_DMA_ADDRESS)); 2289bbddff05STejun Heo if (!ai || !fc) 2290bbddff05STejun Heo panic("Failed to allocate memory for percpu areas."); 2291100d13c3SCatalin Marinas /* kmemleak tracks the percpu allocations separately */ 2292100d13c3SCatalin Marinas kmemleak_free(fc); 2293bbddff05STejun Heo 2294bbddff05STejun Heo ai->dyn_size = unit_size; 2295bbddff05STejun Heo ai->unit_size = unit_size; 2296bbddff05STejun Heo ai->atom_size = unit_size; 2297bbddff05STejun Heo ai->alloc_size = unit_size; 2298bbddff05STejun Heo ai->groups[0].nr_units = 1; 2299bbddff05STejun Heo ai->groups[0].cpu_map[0] = 0; 2300bbddff05STejun Heo 2301bbddff05STejun Heo if (pcpu_setup_first_chunk(ai, fc) < 0) 2302bbddff05STejun Heo panic("Failed to initialize percpu areas."); 2303bbddff05STejun Heo } 2304bbddff05STejun Heo 2305bbddff05STejun Heo #endif /* CONFIG_SMP */ 2306bbddff05STejun Heo 2307099a19d9STejun Heo /* 2308099a19d9STejun Heo * First and reserved chunks are initialized with temporary allocation 2309099a19d9STejun Heo * map in initdata so that they can be used before slab is online. 2310099a19d9STejun Heo * This function is called after slab is brought up and replaces those 2311099a19d9STejun Heo * with properly allocated maps. 2312099a19d9STejun Heo */ 2313099a19d9STejun Heo void __init percpu_init_late(void) 2314099a19d9STejun Heo { 2315099a19d9STejun Heo struct pcpu_chunk *target_chunks[] = 2316099a19d9STejun Heo { pcpu_first_chunk, pcpu_reserved_chunk, NULL }; 2317099a19d9STejun Heo struct pcpu_chunk *chunk; 2318099a19d9STejun Heo unsigned long flags; 2319099a19d9STejun Heo int i; 2320099a19d9STejun Heo 2321099a19d9STejun Heo for (i = 0; (chunk = target_chunks[i]); i++) { 2322099a19d9STejun Heo int *map; 2323099a19d9STejun Heo const size_t size = PERCPU_DYNAMIC_EARLY_SLOTS * sizeof(map[0]); 2324099a19d9STejun Heo 2325099a19d9STejun Heo BUILD_BUG_ON(size > PAGE_SIZE); 2326099a19d9STejun Heo 232790459ce0SBob Liu map = pcpu_mem_zalloc(size); 2328099a19d9STejun Heo BUG_ON(!map); 2329099a19d9STejun Heo 2330099a19d9STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 2331099a19d9STejun Heo memcpy(map, chunk->map, size); 2332099a19d9STejun Heo chunk->map = map; 2333099a19d9STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 2334099a19d9STejun Heo } 2335099a19d9STejun Heo } 23361a4d7607STejun Heo 23371a4d7607STejun Heo /* 23381a4d7607STejun Heo * Percpu allocator is initialized early during boot when neither slab or 23391a4d7607STejun Heo * workqueue is available. Plug async management until everything is up 23401a4d7607STejun Heo * and running. 23411a4d7607STejun Heo */ 23421a4d7607STejun Heo static int __init percpu_enable_async(void) 23431a4d7607STejun Heo { 23441a4d7607STejun Heo pcpu_async_enabled = true; 23451a4d7607STejun Heo return 0; 23461a4d7607STejun Heo } 23471a4d7607STejun Heo subsys_initcall(percpu_enable_async); 2348