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 * 7fbf59bc9STejun Heo * This file is released under the GPLv2. 8fbf59bc9STejun Heo * 9fbf59bc9STejun Heo * This is percpu allocator which can handle both static and dynamic 1088999a89STejun Heo * areas. Percpu areas are allocated in chunks. Each chunk is 1188999a89STejun Heo * consisted of boot-time determined number of units and the first 1288999a89STejun Heo * chunk is used for static percpu variables in the kernel image 132f39e637STejun Heo * (special boot time alloc/init handling necessary as these areas 142f39e637STejun Heo * need to be brought up before allocation services are running). 152f39e637STejun Heo * Unit grows as necessary and all units grow or shrink in unison. 1688999a89STejun Heo * When a chunk is filled up, another chunk is allocated. 17fbf59bc9STejun Heo * 18fbf59bc9STejun Heo * c0 c1 c2 19fbf59bc9STejun Heo * ------------------- ------------------- ------------ 20fbf59bc9STejun Heo * | u0 | u1 | u2 | u3 | | u0 | u1 | u2 | u3 | | u0 | u1 | u 21fbf59bc9STejun Heo * ------------------- ...... ------------------- .... ------------ 22fbf59bc9STejun Heo * 23fbf59bc9STejun Heo * Allocation is done in offset-size areas of single unit space. Ie, 24fbf59bc9STejun Heo * an area of 512 bytes at 6k in c1 occupies 512 bytes at 6k of c1:u0, 252f39e637STejun Heo * c1:u1, c1:u2 and c1:u3. On UMA, units corresponds directly to 262f39e637STejun Heo * cpus. On NUMA, the mapping can be non-linear and even sparse. 272f39e637STejun Heo * Percpu access can be done by configuring percpu base registers 282f39e637STejun Heo * according to cpu to unit mapping and pcpu_unit_size. 29fbf59bc9STejun Heo * 302f39e637STejun Heo * There are usually many small percpu allocations many of them being 312f39e637STejun Heo * as small as 4 bytes. The allocator organizes chunks into lists 32fbf59bc9STejun Heo * according to free size and tries to allocate from the fullest one. 33fbf59bc9STejun Heo * Each chunk keeps the maximum contiguous area size hint which is 344785879eSNamhyung Kim * guaranteed to be equal to or larger than the maximum contiguous 35fbf59bc9STejun Heo * area in the chunk. This helps the allocator not to iterate the 36fbf59bc9STejun Heo * chunk maps unnecessarily. 37fbf59bc9STejun Heo * 38fbf59bc9STejun Heo * Allocation state in each chunk is kept using an array of integers 39fbf59bc9STejun Heo * on chunk->map. A positive value in the map represents a free 40fbf59bc9STejun Heo * region and negative allocated. Allocation inside a chunk is done 41fbf59bc9STejun Heo * by scanning this map sequentially and serving the first matching 42fbf59bc9STejun Heo * entry. This is mostly copied from the percpu_modalloc() allocator. 43e1b9aa3fSChristoph Lameter * Chunks can be determined from the address using the index field 44e1b9aa3fSChristoph Lameter * in the page struct. The index field contains a pointer to the chunk. 45fbf59bc9STejun Heo * 46fbf59bc9STejun Heo * To use this allocator, arch code should do the followings. 47fbf59bc9STejun Heo * 48fbf59bc9STejun Heo * - define __addr_to_pcpu_ptr() and __pcpu_ptr_to_addr() to translate 49e0100983STejun Heo * regular address to percpu pointer and back if they need to be 50e0100983STejun Heo * different from the default 51fbf59bc9STejun Heo * 528d408b4bSTejun Heo * - use pcpu_setup_first_chunk() during percpu area initialization to 538d408b4bSTejun Heo * setup the first chunk containing the kernel static percpu area 54fbf59bc9STejun Heo */ 55fbf59bc9STejun Heo 56fbf59bc9STejun Heo #include <linux/bitmap.h> 57fbf59bc9STejun Heo #include <linux/bootmem.h> 58fd1e8a1fSTejun Heo #include <linux/err.h> 59fbf59bc9STejun Heo #include <linux/list.h> 60a530b795STejun Heo #include <linux/log2.h> 61fbf59bc9STejun Heo #include <linux/mm.h> 62fbf59bc9STejun Heo #include <linux/module.h> 63fbf59bc9STejun Heo #include <linux/mutex.h> 64fbf59bc9STejun Heo #include <linux/percpu.h> 65fbf59bc9STejun Heo #include <linux/pfn.h> 66fbf59bc9STejun Heo #include <linux/slab.h> 67ccea34b5STejun Heo #include <linux/spinlock.h> 68fbf59bc9STejun Heo #include <linux/vmalloc.h> 69a56dbddfSTejun Heo #include <linux/workqueue.h> 70f528f0b8SCatalin Marinas #include <linux/kmemleak.h> 71fbf59bc9STejun Heo 72fbf59bc9STejun Heo #include <asm/cacheflush.h> 73e0100983STejun Heo #include <asm/sections.h> 74fbf59bc9STejun Heo #include <asm/tlbflush.h> 753b034b0dSVivek Goyal #include <asm/io.h> 76fbf59bc9STejun Heo 77fbf59bc9STejun Heo #define PCPU_SLOT_BASE_SHIFT 5 /* 1-31 shares the same slot */ 78fbf59bc9STejun Heo #define PCPU_DFL_MAP_ALLOC 16 /* start a map with 16 ents */ 799c824b6aSTejun Heo #define PCPU_ATOMIC_MAP_MARGIN_LOW 32 809c824b6aSTejun Heo #define PCPU_ATOMIC_MAP_MARGIN_HIGH 64 811a4d7607STejun Heo #define PCPU_EMPTY_POP_PAGES_LOW 2 821a4d7607STejun Heo #define PCPU_EMPTY_POP_PAGES_HIGH 4 83fbf59bc9STejun Heo 84bbddff05STejun Heo #ifdef CONFIG_SMP 85e0100983STejun Heo /* default addr <-> pcpu_ptr mapping, override in asm/percpu.h if necessary */ 86e0100983STejun Heo #ifndef __addr_to_pcpu_ptr 87e0100983STejun Heo #define __addr_to_pcpu_ptr(addr) \ 8843cf38ebSTejun Heo (void __percpu *)((unsigned long)(addr) - \ 8943cf38ebSTejun Heo (unsigned long)pcpu_base_addr + \ 9043cf38ebSTejun Heo (unsigned long)__per_cpu_start) 91e0100983STejun Heo #endif 92e0100983STejun Heo #ifndef __pcpu_ptr_to_addr 93e0100983STejun Heo #define __pcpu_ptr_to_addr(ptr) \ 9443cf38ebSTejun Heo (void __force *)((unsigned long)(ptr) + \ 9543cf38ebSTejun Heo (unsigned long)pcpu_base_addr - \ 9643cf38ebSTejun Heo (unsigned long)__per_cpu_start) 97e0100983STejun Heo #endif 98bbddff05STejun Heo #else /* CONFIG_SMP */ 99bbddff05STejun Heo /* on UP, it's always identity mapped */ 100bbddff05STejun Heo #define __addr_to_pcpu_ptr(addr) (void __percpu *)(addr) 101bbddff05STejun Heo #define __pcpu_ptr_to_addr(ptr) (void __force *)(ptr) 102bbddff05STejun Heo #endif /* CONFIG_SMP */ 103e0100983STejun Heo 104fbf59bc9STejun Heo struct pcpu_chunk { 105fbf59bc9STejun Heo struct list_head list; /* linked to pcpu_slot lists */ 106fbf59bc9STejun Heo int free_size; /* free bytes in the chunk */ 107fbf59bc9STejun Heo int contig_hint; /* max contiguous size hint */ 108bba174f5STejun Heo void *base_addr; /* base address of this chunk */ 1099c824b6aSTejun Heo 110723ad1d9SAl Viro int map_used; /* # of map entries used before the sentry */ 111fbf59bc9STejun Heo int map_alloc; /* # of map entries allocated */ 112fbf59bc9STejun Heo int *map; /* allocation map */ 1139c824b6aSTejun Heo struct work_struct map_extend_work;/* async ->map[] extension */ 1149c824b6aSTejun Heo 11588999a89STejun Heo void *data; /* chunk data */ 1163d331ad7SAl Viro int first_free; /* no free below this */ 1178d408b4bSTejun Heo bool immutable; /* no [de]population allowed */ 118b539b87fSTejun Heo int nr_populated; /* # of populated pages */ 119ce3141a2STejun Heo unsigned long populated[]; /* populated bitmap */ 120fbf59bc9STejun Heo }; 121fbf59bc9STejun Heo 12240150d37STejun Heo static int pcpu_unit_pages __read_mostly; 12340150d37STejun Heo static int pcpu_unit_size __read_mostly; 1242f39e637STejun Heo static int pcpu_nr_units __read_mostly; 1256563297cSTejun Heo static int pcpu_atom_size __read_mostly; 12640150d37STejun Heo static int pcpu_nr_slots __read_mostly; 12740150d37STejun Heo static size_t pcpu_chunk_struct_size __read_mostly; 128fbf59bc9STejun Heo 129a855b84cSTejun Heo /* cpus with the lowest and highest unit addresses */ 130a855b84cSTejun Heo static unsigned int pcpu_low_unit_cpu __read_mostly; 131a855b84cSTejun Heo static unsigned int pcpu_high_unit_cpu __read_mostly; 1322f39e637STejun Heo 133fbf59bc9STejun Heo /* the address of the first chunk which starts with the kernel static area */ 13440150d37STejun Heo void *pcpu_base_addr __read_mostly; 135fbf59bc9STejun Heo EXPORT_SYMBOL_GPL(pcpu_base_addr); 136fbf59bc9STejun Heo 137fb435d52STejun Heo static const int *pcpu_unit_map __read_mostly; /* cpu -> unit */ 138fb435d52STejun Heo const unsigned long *pcpu_unit_offsets __read_mostly; /* cpu -> unit offset */ 1392f39e637STejun Heo 1406563297cSTejun Heo /* group information, used for vm allocation */ 1416563297cSTejun Heo static int pcpu_nr_groups __read_mostly; 1426563297cSTejun Heo static const unsigned long *pcpu_group_offsets __read_mostly; 1436563297cSTejun Heo static const size_t *pcpu_group_sizes __read_mostly; 1446563297cSTejun Heo 145ae9e6bc9STejun Heo /* 146ae9e6bc9STejun Heo * The first chunk which always exists. Note that unlike other 147ae9e6bc9STejun Heo * chunks, this one can be allocated and mapped in several different 148ae9e6bc9STejun Heo * ways and thus often doesn't live in the vmalloc area. 149ae9e6bc9STejun Heo */ 150ae9e6bc9STejun Heo static struct pcpu_chunk *pcpu_first_chunk; 151ae9e6bc9STejun Heo 152ae9e6bc9STejun Heo /* 153ae9e6bc9STejun Heo * Optional reserved chunk. This chunk reserves part of the first 154ae9e6bc9STejun Heo * chunk and serves it for reserved allocations. The amount of 155ae9e6bc9STejun Heo * reserved offset is in pcpu_reserved_chunk_limit. When reserved 156ae9e6bc9STejun Heo * area doesn't exist, the following variables contain NULL and 0 157ae9e6bc9STejun Heo * respectively. 158ae9e6bc9STejun Heo */ 159edcb4639STejun Heo static struct pcpu_chunk *pcpu_reserved_chunk; 160edcb4639STejun Heo static int pcpu_reserved_chunk_limit; 161edcb4639STejun Heo 162b38d08f3STejun Heo static DEFINE_SPINLOCK(pcpu_lock); /* all internal data structures */ 163b38d08f3STejun Heo static DEFINE_MUTEX(pcpu_alloc_mutex); /* chunk create/destroy, [de]pop */ 164fbf59bc9STejun Heo 16540150d37STejun Heo static struct list_head *pcpu_slot __read_mostly; /* chunk list slots */ 166fbf59bc9STejun Heo 167b539b87fSTejun Heo /* 168b539b87fSTejun Heo * The number of empty populated pages, protected by pcpu_lock. The 169b539b87fSTejun Heo * reserved chunk doesn't contribute to the count. 170b539b87fSTejun Heo */ 171b539b87fSTejun Heo static int pcpu_nr_empty_pop_pages; 172b539b87fSTejun Heo 1731a4d7607STejun Heo /* 1741a4d7607STejun Heo * Balance work is used to populate or destroy chunks asynchronously. We 1751a4d7607STejun Heo * try to keep the number of populated free pages between 1761a4d7607STejun Heo * PCPU_EMPTY_POP_PAGES_LOW and HIGH for atomic allocations and at most one 1771a4d7607STejun Heo * empty chunk. 1781a4d7607STejun Heo */ 179fe6bd8c3STejun Heo static void pcpu_balance_workfn(struct work_struct *work); 180fe6bd8c3STejun Heo static DECLARE_WORK(pcpu_balance_work, pcpu_balance_workfn); 1811a4d7607STejun Heo static bool pcpu_async_enabled __read_mostly; 1821a4d7607STejun Heo static bool pcpu_atomic_alloc_failed; 1831a4d7607STejun Heo 1841a4d7607STejun Heo static void pcpu_schedule_balance_work(void) 1851a4d7607STejun Heo { 1861a4d7607STejun Heo if (pcpu_async_enabled) 1871a4d7607STejun Heo schedule_work(&pcpu_balance_work); 1881a4d7607STejun Heo } 189a56dbddfSTejun Heo 190020ec653STejun Heo static bool pcpu_addr_in_first_chunk(void *addr) 191020ec653STejun Heo { 192020ec653STejun Heo void *first_start = pcpu_first_chunk->base_addr; 193020ec653STejun Heo 194020ec653STejun Heo return addr >= first_start && addr < first_start + pcpu_unit_size; 195020ec653STejun Heo } 196020ec653STejun Heo 197020ec653STejun Heo static bool pcpu_addr_in_reserved_chunk(void *addr) 198020ec653STejun Heo { 199020ec653STejun Heo void *first_start = pcpu_first_chunk->base_addr; 200020ec653STejun Heo 201020ec653STejun Heo return addr >= first_start && 202020ec653STejun Heo addr < first_start + pcpu_reserved_chunk_limit; 203020ec653STejun Heo } 204020ec653STejun Heo 205d9b55eebSTejun Heo static int __pcpu_size_to_slot(int size) 206fbf59bc9STejun Heo { 207cae3aeb8STejun Heo int highbit = fls(size); /* size is in bytes */ 208fbf59bc9STejun Heo return max(highbit - PCPU_SLOT_BASE_SHIFT + 2, 1); 209fbf59bc9STejun Heo } 210fbf59bc9STejun Heo 211d9b55eebSTejun Heo static int pcpu_size_to_slot(int size) 212d9b55eebSTejun Heo { 213d9b55eebSTejun Heo if (size == pcpu_unit_size) 214d9b55eebSTejun Heo return pcpu_nr_slots - 1; 215d9b55eebSTejun Heo return __pcpu_size_to_slot(size); 216d9b55eebSTejun Heo } 217d9b55eebSTejun Heo 218fbf59bc9STejun Heo static int pcpu_chunk_slot(const struct pcpu_chunk *chunk) 219fbf59bc9STejun Heo { 220fbf59bc9STejun Heo if (chunk->free_size < sizeof(int) || chunk->contig_hint < sizeof(int)) 221fbf59bc9STejun Heo return 0; 222fbf59bc9STejun Heo 223fbf59bc9STejun Heo return pcpu_size_to_slot(chunk->free_size); 224fbf59bc9STejun Heo } 225fbf59bc9STejun Heo 22688999a89STejun Heo /* set the pointer to a chunk in a page struct */ 22788999a89STejun Heo static void pcpu_set_page_chunk(struct page *page, struct pcpu_chunk *pcpu) 22888999a89STejun Heo { 22988999a89STejun Heo page->index = (unsigned long)pcpu; 23088999a89STejun Heo } 23188999a89STejun Heo 23288999a89STejun Heo /* obtain pointer to a chunk from a page struct */ 23388999a89STejun Heo static struct pcpu_chunk *pcpu_get_page_chunk(struct page *page) 23488999a89STejun Heo { 23588999a89STejun Heo return (struct pcpu_chunk *)page->index; 23688999a89STejun Heo } 23788999a89STejun Heo 23888999a89STejun Heo static int __maybe_unused pcpu_page_idx(unsigned int cpu, int page_idx) 239fbf59bc9STejun Heo { 2402f39e637STejun Heo return pcpu_unit_map[cpu] * pcpu_unit_pages + page_idx; 241fbf59bc9STejun Heo } 242fbf59bc9STejun Heo 2439983b6f0STejun Heo static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk, 244fbf59bc9STejun Heo unsigned int cpu, int page_idx) 245fbf59bc9STejun Heo { 246bba174f5STejun Heo return (unsigned long)chunk->base_addr + pcpu_unit_offsets[cpu] + 247fb435d52STejun Heo (page_idx << PAGE_SHIFT); 248fbf59bc9STejun Heo } 249fbf59bc9STejun Heo 25088999a89STejun Heo static void __maybe_unused pcpu_next_unpop(struct pcpu_chunk *chunk, 25188999a89STejun Heo int *rs, int *re, int end) 252ce3141a2STejun Heo { 253ce3141a2STejun Heo *rs = find_next_zero_bit(chunk->populated, end, *rs); 254ce3141a2STejun Heo *re = find_next_bit(chunk->populated, end, *rs + 1); 255ce3141a2STejun Heo } 256ce3141a2STejun Heo 25788999a89STejun Heo static void __maybe_unused pcpu_next_pop(struct pcpu_chunk *chunk, 25888999a89STejun Heo int *rs, int *re, int end) 259ce3141a2STejun Heo { 260ce3141a2STejun Heo *rs = find_next_bit(chunk->populated, end, *rs); 261ce3141a2STejun Heo *re = find_next_zero_bit(chunk->populated, end, *rs + 1); 262ce3141a2STejun Heo } 263ce3141a2STejun Heo 264ce3141a2STejun Heo /* 265ce3141a2STejun Heo * (Un)populated page region iterators. Iterate over (un)populated 266b595076aSUwe Kleine-König * page regions between @start and @end in @chunk. @rs and @re should 267ce3141a2STejun Heo * be integer variables and will be set to start and end page index of 268ce3141a2STejun Heo * the current region. 269ce3141a2STejun Heo */ 270ce3141a2STejun Heo #define pcpu_for_each_unpop_region(chunk, rs, re, start, end) \ 271ce3141a2STejun Heo for ((rs) = (start), pcpu_next_unpop((chunk), &(rs), &(re), (end)); \ 272ce3141a2STejun Heo (rs) < (re); \ 273ce3141a2STejun Heo (rs) = (re) + 1, pcpu_next_unpop((chunk), &(rs), &(re), (end))) 274ce3141a2STejun Heo 275ce3141a2STejun Heo #define pcpu_for_each_pop_region(chunk, rs, re, start, end) \ 276ce3141a2STejun Heo for ((rs) = (start), pcpu_next_pop((chunk), &(rs), &(re), (end)); \ 277ce3141a2STejun Heo (rs) < (re); \ 278ce3141a2STejun Heo (rs) = (re) + 1, pcpu_next_pop((chunk), &(rs), &(re), (end))) 279ce3141a2STejun Heo 280fbf59bc9STejun Heo /** 28190459ce0SBob Liu * pcpu_mem_zalloc - allocate memory 2821880d93bSTejun Heo * @size: bytes to allocate 283fbf59bc9STejun Heo * 2841880d93bSTejun Heo * Allocate @size bytes. If @size is smaller than PAGE_SIZE, 28590459ce0SBob Liu * kzalloc() is used; otherwise, vzalloc() is used. The returned 2861880d93bSTejun Heo * memory is always zeroed. 287fbf59bc9STejun Heo * 288ccea34b5STejun Heo * CONTEXT: 289ccea34b5STejun Heo * Does GFP_KERNEL allocation. 290ccea34b5STejun Heo * 291fbf59bc9STejun Heo * RETURNS: 2921880d93bSTejun Heo * Pointer to the allocated area on success, NULL on failure. 293fbf59bc9STejun Heo */ 29490459ce0SBob Liu static void *pcpu_mem_zalloc(size_t size) 295fbf59bc9STejun Heo { 296099a19d9STejun Heo if (WARN_ON_ONCE(!slab_is_available())) 297099a19d9STejun Heo return NULL; 298099a19d9STejun Heo 299fbf59bc9STejun Heo if (size <= PAGE_SIZE) 3001880d93bSTejun Heo return kzalloc(size, GFP_KERNEL); 3017af4c093SJesper Juhl else 3027af4c093SJesper Juhl return vzalloc(size); 3031880d93bSTejun Heo } 304fbf59bc9STejun Heo 3051880d93bSTejun Heo /** 3061880d93bSTejun Heo * pcpu_mem_free - free memory 3071880d93bSTejun Heo * @ptr: memory to free 3081880d93bSTejun Heo * @size: size of the area 3091880d93bSTejun Heo * 31090459ce0SBob Liu * Free @ptr. @ptr should have been allocated using pcpu_mem_zalloc(). 3111880d93bSTejun Heo */ 3121880d93bSTejun Heo static void pcpu_mem_free(void *ptr, size_t size) 3131880d93bSTejun Heo { 3141880d93bSTejun Heo if (size <= PAGE_SIZE) 3151880d93bSTejun Heo kfree(ptr); 3161880d93bSTejun Heo else 3171880d93bSTejun Heo vfree(ptr); 318fbf59bc9STejun Heo } 319fbf59bc9STejun Heo 320fbf59bc9STejun Heo /** 321b539b87fSTejun Heo * pcpu_count_occupied_pages - count the number of pages an area occupies 322b539b87fSTejun Heo * @chunk: chunk of interest 323b539b87fSTejun Heo * @i: index of the area in question 324b539b87fSTejun Heo * 325b539b87fSTejun Heo * Count the number of pages chunk's @i'th area occupies. When the area's 326b539b87fSTejun Heo * start and/or end address isn't aligned to page boundary, the straddled 327b539b87fSTejun Heo * page is included in the count iff the rest of the page is free. 328b539b87fSTejun Heo */ 329b539b87fSTejun Heo static int pcpu_count_occupied_pages(struct pcpu_chunk *chunk, int i) 330b539b87fSTejun Heo { 331b539b87fSTejun Heo int off = chunk->map[i] & ~1; 332b539b87fSTejun Heo int end = chunk->map[i + 1] & ~1; 333b539b87fSTejun Heo 334b539b87fSTejun Heo if (!PAGE_ALIGNED(off) && i > 0) { 335b539b87fSTejun Heo int prev = chunk->map[i - 1]; 336b539b87fSTejun Heo 337b539b87fSTejun Heo if (!(prev & 1) && prev <= round_down(off, PAGE_SIZE)) 338b539b87fSTejun Heo off = round_down(off, PAGE_SIZE); 339b539b87fSTejun Heo } 340b539b87fSTejun Heo 341b539b87fSTejun Heo if (!PAGE_ALIGNED(end) && i + 1 < chunk->map_used) { 342b539b87fSTejun Heo int next = chunk->map[i + 1]; 343b539b87fSTejun Heo int nend = chunk->map[i + 2] & ~1; 344b539b87fSTejun Heo 345b539b87fSTejun Heo if (!(next & 1) && nend >= round_up(end, PAGE_SIZE)) 346b539b87fSTejun Heo end = round_up(end, PAGE_SIZE); 347b539b87fSTejun Heo } 348b539b87fSTejun Heo 349b539b87fSTejun Heo return max_t(int, PFN_DOWN(end) - PFN_UP(off), 0); 350b539b87fSTejun Heo } 351b539b87fSTejun Heo 352b539b87fSTejun Heo /** 353fbf59bc9STejun Heo * pcpu_chunk_relocate - put chunk in the appropriate chunk slot 354fbf59bc9STejun Heo * @chunk: chunk of interest 355fbf59bc9STejun Heo * @oslot: the previous slot it was on 356fbf59bc9STejun Heo * 357fbf59bc9STejun Heo * This function is called after an allocation or free changed @chunk. 358fbf59bc9STejun Heo * New slot according to the changed state is determined and @chunk is 359edcb4639STejun Heo * moved to the slot. Note that the reserved chunk is never put on 360edcb4639STejun Heo * chunk slots. 361ccea34b5STejun Heo * 362ccea34b5STejun Heo * CONTEXT: 363ccea34b5STejun Heo * pcpu_lock. 364fbf59bc9STejun Heo */ 365fbf59bc9STejun Heo static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot) 366fbf59bc9STejun Heo { 367fbf59bc9STejun Heo int nslot = pcpu_chunk_slot(chunk); 368fbf59bc9STejun Heo 369edcb4639STejun Heo if (chunk != pcpu_reserved_chunk && oslot != nslot) { 370fbf59bc9STejun Heo if (oslot < nslot) 371fbf59bc9STejun Heo list_move(&chunk->list, &pcpu_slot[nslot]); 372fbf59bc9STejun Heo else 373fbf59bc9STejun Heo list_move_tail(&chunk->list, &pcpu_slot[nslot]); 374fbf59bc9STejun Heo } 375fbf59bc9STejun Heo } 376fbf59bc9STejun Heo 377fbf59bc9STejun Heo /** 378833af842STejun Heo * pcpu_need_to_extend - determine whether chunk area map needs to be extended 379833af842STejun Heo * @chunk: chunk of interest 3809c824b6aSTejun Heo * @is_atomic: the allocation context 3819f7dcf22STejun Heo * 3829c824b6aSTejun Heo * Determine whether area map of @chunk needs to be extended. If 3839c824b6aSTejun Heo * @is_atomic, only the amount necessary for a new allocation is 3849c824b6aSTejun Heo * considered; however, async extension is scheduled if the left amount is 3859c824b6aSTejun Heo * low. If !@is_atomic, it aims for more empty space. Combined, this 3869c824b6aSTejun Heo * ensures that the map is likely to have enough available space to 3879c824b6aSTejun Heo * accomodate atomic allocations which can't extend maps directly. 3889f7dcf22STejun Heo * 389ccea34b5STejun Heo * CONTEXT: 390833af842STejun Heo * pcpu_lock. 391ccea34b5STejun Heo * 3929f7dcf22STejun Heo * RETURNS: 393833af842STejun Heo * New target map allocation length if extension is necessary, 0 394833af842STejun Heo * otherwise. 3959f7dcf22STejun Heo */ 3969c824b6aSTejun Heo static int pcpu_need_to_extend(struct pcpu_chunk *chunk, bool is_atomic) 3979f7dcf22STejun Heo { 3989c824b6aSTejun Heo int margin, new_alloc; 3999f7dcf22STejun Heo 4009c824b6aSTejun Heo if (is_atomic) { 4019c824b6aSTejun Heo margin = 3; 4029c824b6aSTejun Heo 4039c824b6aSTejun Heo if (chunk->map_alloc < 4041a4d7607STejun Heo chunk->map_used + PCPU_ATOMIC_MAP_MARGIN_LOW && 4051a4d7607STejun Heo pcpu_async_enabled) 4069c824b6aSTejun Heo schedule_work(&chunk->map_extend_work); 4079c824b6aSTejun Heo } else { 4089c824b6aSTejun Heo margin = PCPU_ATOMIC_MAP_MARGIN_HIGH; 4099c824b6aSTejun Heo } 4109c824b6aSTejun Heo 4119c824b6aSTejun Heo if (chunk->map_alloc >= chunk->map_used + margin) 4129f7dcf22STejun Heo return 0; 4139f7dcf22STejun Heo 4149f7dcf22STejun Heo new_alloc = PCPU_DFL_MAP_ALLOC; 4159c824b6aSTejun Heo while (new_alloc < chunk->map_used + margin) 4169f7dcf22STejun Heo new_alloc *= 2; 4179f7dcf22STejun Heo 418833af842STejun Heo return new_alloc; 419ccea34b5STejun Heo } 420ccea34b5STejun Heo 421833af842STejun Heo /** 422833af842STejun Heo * pcpu_extend_area_map - extend area map of a chunk 423833af842STejun Heo * @chunk: chunk of interest 424833af842STejun Heo * @new_alloc: new target allocation length of the area map 425833af842STejun Heo * 426833af842STejun Heo * Extend area map of @chunk to have @new_alloc entries. 427833af842STejun Heo * 428833af842STejun Heo * CONTEXT: 429833af842STejun Heo * Does GFP_KERNEL allocation. Grabs and releases pcpu_lock. 430833af842STejun Heo * 431833af842STejun Heo * RETURNS: 432833af842STejun Heo * 0 on success, -errno on failure. 433ccea34b5STejun Heo */ 434833af842STejun Heo static int pcpu_extend_area_map(struct pcpu_chunk *chunk, int new_alloc) 435833af842STejun Heo { 436833af842STejun Heo int *old = NULL, *new = NULL; 437833af842STejun Heo size_t old_size = 0, new_size = new_alloc * sizeof(new[0]); 438833af842STejun Heo unsigned long flags; 4399f7dcf22STejun Heo 44090459ce0SBob Liu new = pcpu_mem_zalloc(new_size); 441833af842STejun Heo if (!new) 442833af842STejun Heo return -ENOMEM; 443833af842STejun Heo 444833af842STejun Heo /* acquire pcpu_lock and switch to new area map */ 445833af842STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 446833af842STejun Heo 447833af842STejun Heo if (new_alloc <= chunk->map_alloc) 448833af842STejun Heo goto out_unlock; 449833af842STejun Heo 450833af842STejun Heo old_size = chunk->map_alloc * sizeof(chunk->map[0]); 451a002d148SHuang Shijie old = chunk->map; 452a002d148SHuang Shijie 453a002d148SHuang Shijie memcpy(new, old, old_size); 4549f7dcf22STejun Heo 4559f7dcf22STejun Heo chunk->map_alloc = new_alloc; 4569f7dcf22STejun Heo chunk->map = new; 457833af842STejun Heo new = NULL; 458833af842STejun Heo 459833af842STejun Heo out_unlock: 460833af842STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 461833af842STejun Heo 462833af842STejun Heo /* 463833af842STejun Heo * pcpu_mem_free() might end up calling vfree() which uses 464833af842STejun Heo * IRQ-unsafe lock and thus can't be called under pcpu_lock. 465833af842STejun Heo */ 466833af842STejun Heo pcpu_mem_free(old, old_size); 467833af842STejun Heo pcpu_mem_free(new, new_size); 468833af842STejun Heo 4699f7dcf22STejun Heo return 0; 4709f7dcf22STejun Heo } 4719f7dcf22STejun Heo 4729c824b6aSTejun Heo static void pcpu_map_extend_workfn(struct work_struct *work) 4739c824b6aSTejun Heo { 4749c824b6aSTejun Heo struct pcpu_chunk *chunk = container_of(work, struct pcpu_chunk, 4759c824b6aSTejun Heo map_extend_work); 4769c824b6aSTejun Heo int new_alloc; 4779c824b6aSTejun Heo 4789c824b6aSTejun Heo spin_lock_irq(&pcpu_lock); 4799c824b6aSTejun Heo new_alloc = pcpu_need_to_extend(chunk, false); 4809c824b6aSTejun Heo spin_unlock_irq(&pcpu_lock); 4819c824b6aSTejun Heo 4829c824b6aSTejun Heo if (new_alloc) 4839c824b6aSTejun Heo pcpu_extend_area_map(chunk, new_alloc); 4849c824b6aSTejun Heo } 4859c824b6aSTejun Heo 4869f7dcf22STejun Heo /** 487a16037c8STejun Heo * pcpu_fit_in_area - try to fit the requested allocation in a candidate area 488a16037c8STejun Heo * @chunk: chunk the candidate area belongs to 489a16037c8STejun Heo * @off: the offset to the start of the candidate area 490a16037c8STejun Heo * @this_size: the size of the candidate area 491a16037c8STejun Heo * @size: the size of the target allocation 492a16037c8STejun Heo * @align: the alignment of the target allocation 493a16037c8STejun Heo * @pop_only: only allocate from already populated region 494a16037c8STejun Heo * 495a16037c8STejun Heo * We're trying to allocate @size bytes aligned at @align. @chunk's area 496a16037c8STejun Heo * at @off sized @this_size is a candidate. This function determines 497a16037c8STejun Heo * whether the target allocation fits in the candidate area and returns the 498a16037c8STejun Heo * number of bytes to pad after @off. If the target area doesn't fit, -1 499a16037c8STejun Heo * is returned. 500a16037c8STejun Heo * 501a16037c8STejun Heo * If @pop_only is %true, this function only considers the already 502a16037c8STejun Heo * populated part of the candidate area. 503a16037c8STejun Heo */ 504a16037c8STejun Heo static int pcpu_fit_in_area(struct pcpu_chunk *chunk, int off, int this_size, 505a16037c8STejun Heo int size, int align, bool pop_only) 506a16037c8STejun Heo { 507a16037c8STejun Heo int cand_off = off; 508a16037c8STejun Heo 509a16037c8STejun Heo while (true) { 510a16037c8STejun Heo int head = ALIGN(cand_off, align) - off; 511a16037c8STejun Heo int page_start, page_end, rs, re; 512a16037c8STejun Heo 513a16037c8STejun Heo if (this_size < head + size) 514a16037c8STejun Heo return -1; 515a16037c8STejun Heo 516a16037c8STejun Heo if (!pop_only) 517a16037c8STejun Heo return head; 518a16037c8STejun Heo 519a16037c8STejun Heo /* 520a16037c8STejun Heo * If the first unpopulated page is beyond the end of the 521a16037c8STejun Heo * allocation, the whole allocation is populated; 522a16037c8STejun Heo * otherwise, retry from the end of the unpopulated area. 523a16037c8STejun Heo */ 524a16037c8STejun Heo page_start = PFN_DOWN(head + off); 525a16037c8STejun Heo page_end = PFN_UP(head + off + size); 526a16037c8STejun Heo 527a16037c8STejun Heo rs = page_start; 528a16037c8STejun Heo pcpu_next_unpop(chunk, &rs, &re, PFN_UP(off + this_size)); 529a16037c8STejun Heo if (rs >= page_end) 530a16037c8STejun Heo return head; 531a16037c8STejun Heo cand_off = re * PAGE_SIZE; 532a16037c8STejun Heo } 533a16037c8STejun Heo } 534a16037c8STejun Heo 535a16037c8STejun Heo /** 536fbf59bc9STejun Heo * pcpu_alloc_area - allocate area from a pcpu_chunk 537fbf59bc9STejun Heo * @chunk: chunk of interest 538cae3aeb8STejun Heo * @size: wanted size in bytes 539fbf59bc9STejun Heo * @align: wanted align 540a16037c8STejun Heo * @pop_only: allocate only from the populated area 541b539b87fSTejun Heo * @occ_pages_p: out param for the number of pages the area occupies 542fbf59bc9STejun Heo * 543fbf59bc9STejun Heo * Try to allocate @size bytes area aligned at @align from @chunk. 544fbf59bc9STejun Heo * Note that this function only allocates the offset. It doesn't 545fbf59bc9STejun Heo * populate or map the area. 546fbf59bc9STejun Heo * 5479f7dcf22STejun Heo * @chunk->map must have at least two free slots. 5489f7dcf22STejun Heo * 549ccea34b5STejun Heo * CONTEXT: 550ccea34b5STejun Heo * pcpu_lock. 551ccea34b5STejun Heo * 552fbf59bc9STejun Heo * RETURNS: 5539f7dcf22STejun Heo * Allocated offset in @chunk on success, -1 if no matching area is 5549f7dcf22STejun Heo * found. 555fbf59bc9STejun Heo */ 556a16037c8STejun Heo static int pcpu_alloc_area(struct pcpu_chunk *chunk, int size, int align, 557b539b87fSTejun Heo bool pop_only, int *occ_pages_p) 558fbf59bc9STejun Heo { 559fbf59bc9STejun Heo int oslot = pcpu_chunk_slot(chunk); 560fbf59bc9STejun Heo int max_contig = 0; 561fbf59bc9STejun Heo int i, off; 5623d331ad7SAl Viro bool seen_free = false; 563723ad1d9SAl Viro int *p; 564fbf59bc9STejun Heo 5653d331ad7SAl Viro for (i = chunk->first_free, p = chunk->map + i; i < chunk->map_used; i++, p++) { 566fbf59bc9STejun Heo int head, tail; 567723ad1d9SAl Viro int this_size; 568723ad1d9SAl Viro 569723ad1d9SAl Viro off = *p; 570723ad1d9SAl Viro if (off & 1) 571723ad1d9SAl Viro continue; 572fbf59bc9STejun Heo 573723ad1d9SAl Viro this_size = (p[1] & ~1) - off; 574a16037c8STejun Heo 575a16037c8STejun Heo head = pcpu_fit_in_area(chunk, off, this_size, size, align, 576a16037c8STejun Heo pop_only); 577a16037c8STejun Heo if (head < 0) { 5783d331ad7SAl Viro if (!seen_free) { 5793d331ad7SAl Viro chunk->first_free = i; 5803d331ad7SAl Viro seen_free = true; 5813d331ad7SAl Viro } 582723ad1d9SAl Viro max_contig = max(this_size, max_contig); 583fbf59bc9STejun Heo continue; 584fbf59bc9STejun Heo } 585fbf59bc9STejun Heo 586fbf59bc9STejun Heo /* 587fbf59bc9STejun Heo * If head is small or the previous block is free, 588fbf59bc9STejun Heo * merge'em. Note that 'small' is defined as smaller 589fbf59bc9STejun Heo * than sizeof(int), which is very small but isn't too 590fbf59bc9STejun Heo * uncommon for percpu allocations. 591fbf59bc9STejun Heo */ 592723ad1d9SAl Viro if (head && (head < sizeof(int) || !(p[-1] & 1))) { 59321ddfd38SJianyu Zhan *p = off += head; 594723ad1d9SAl Viro if (p[-1] & 1) 595fbf59bc9STejun Heo chunk->free_size -= head; 59621ddfd38SJianyu Zhan else 59721ddfd38SJianyu Zhan max_contig = max(*p - p[-1], max_contig); 598723ad1d9SAl Viro this_size -= head; 599fbf59bc9STejun Heo head = 0; 600fbf59bc9STejun Heo } 601fbf59bc9STejun Heo 602fbf59bc9STejun Heo /* if tail is small, just keep it around */ 603723ad1d9SAl Viro tail = this_size - head - size; 604723ad1d9SAl Viro if (tail < sizeof(int)) { 605fbf59bc9STejun Heo tail = 0; 606723ad1d9SAl Viro size = this_size - head; 607723ad1d9SAl Viro } 608fbf59bc9STejun Heo 609fbf59bc9STejun Heo /* split if warranted */ 610fbf59bc9STejun Heo if (head || tail) { 611706c16f2SAl Viro int nr_extra = !!head + !!tail; 612706c16f2SAl Viro 613706c16f2SAl Viro /* insert new subblocks */ 614723ad1d9SAl Viro memmove(p + nr_extra + 1, p + 1, 615706c16f2SAl Viro sizeof(chunk->map[0]) * (chunk->map_used - i)); 616706c16f2SAl Viro chunk->map_used += nr_extra; 617706c16f2SAl Viro 618fbf59bc9STejun Heo if (head) { 6193d331ad7SAl Viro if (!seen_free) { 6203d331ad7SAl Viro chunk->first_free = i; 6213d331ad7SAl Viro seen_free = true; 6223d331ad7SAl Viro } 623723ad1d9SAl Viro *++p = off += head; 624723ad1d9SAl Viro ++i; 625706c16f2SAl Viro max_contig = max(head, max_contig); 626fbf59bc9STejun Heo } 627706c16f2SAl Viro if (tail) { 628723ad1d9SAl Viro p[1] = off + size; 629706c16f2SAl Viro max_contig = max(tail, max_contig); 630706c16f2SAl Viro } 631fbf59bc9STejun Heo } 632fbf59bc9STejun Heo 6333d331ad7SAl Viro if (!seen_free) 6343d331ad7SAl Viro chunk->first_free = i + 1; 6353d331ad7SAl Viro 636fbf59bc9STejun Heo /* update hint and mark allocated */ 637723ad1d9SAl Viro if (i + 1 == chunk->map_used) 638fbf59bc9STejun Heo chunk->contig_hint = max_contig; /* fully scanned */ 639fbf59bc9STejun Heo else 640fbf59bc9STejun Heo chunk->contig_hint = max(chunk->contig_hint, 641fbf59bc9STejun Heo max_contig); 642fbf59bc9STejun Heo 643723ad1d9SAl Viro chunk->free_size -= size; 644723ad1d9SAl Viro *p |= 1; 645fbf59bc9STejun Heo 646b539b87fSTejun Heo *occ_pages_p = pcpu_count_occupied_pages(chunk, i); 647fbf59bc9STejun Heo pcpu_chunk_relocate(chunk, oslot); 648fbf59bc9STejun Heo return off; 649fbf59bc9STejun Heo } 650fbf59bc9STejun Heo 651fbf59bc9STejun Heo chunk->contig_hint = max_contig; /* fully scanned */ 652fbf59bc9STejun Heo pcpu_chunk_relocate(chunk, oslot); 653fbf59bc9STejun Heo 6549f7dcf22STejun Heo /* tell the upper layer that this chunk has no matching area */ 6559f7dcf22STejun Heo return -1; 656fbf59bc9STejun Heo } 657fbf59bc9STejun Heo 658fbf59bc9STejun Heo /** 659fbf59bc9STejun Heo * pcpu_free_area - free area to a pcpu_chunk 660fbf59bc9STejun Heo * @chunk: chunk of interest 661fbf59bc9STejun Heo * @freeme: offset of area to free 662b539b87fSTejun Heo * @occ_pages_p: out param for the number of pages the area occupies 663fbf59bc9STejun Heo * 664fbf59bc9STejun Heo * Free area starting from @freeme to @chunk. Note that this function 665fbf59bc9STejun Heo * only modifies the allocation map. It doesn't depopulate or unmap 666fbf59bc9STejun Heo * the area. 667ccea34b5STejun Heo * 668ccea34b5STejun Heo * CONTEXT: 669ccea34b5STejun Heo * pcpu_lock. 670fbf59bc9STejun Heo */ 671b539b87fSTejun Heo static void pcpu_free_area(struct pcpu_chunk *chunk, int freeme, 672b539b87fSTejun Heo int *occ_pages_p) 673fbf59bc9STejun Heo { 674fbf59bc9STejun Heo int oslot = pcpu_chunk_slot(chunk); 675723ad1d9SAl Viro int off = 0; 676723ad1d9SAl Viro unsigned i, j; 677723ad1d9SAl Viro int to_free = 0; 678723ad1d9SAl Viro int *p; 679fbf59bc9STejun Heo 680723ad1d9SAl Viro freeme |= 1; /* we are searching for <given offset, in use> pair */ 681723ad1d9SAl Viro 682723ad1d9SAl Viro i = 0; 683723ad1d9SAl Viro j = chunk->map_used; 684723ad1d9SAl Viro while (i != j) { 685723ad1d9SAl Viro unsigned k = (i + j) / 2; 686723ad1d9SAl Viro off = chunk->map[k]; 687723ad1d9SAl Viro if (off < freeme) 688723ad1d9SAl Viro i = k + 1; 689723ad1d9SAl Viro else if (off > freeme) 690723ad1d9SAl Viro j = k; 691723ad1d9SAl Viro else 692723ad1d9SAl Viro i = j = k; 693723ad1d9SAl Viro } 694fbf59bc9STejun Heo BUG_ON(off != freeme); 695fbf59bc9STejun Heo 6963d331ad7SAl Viro if (i < chunk->first_free) 6973d331ad7SAl Viro chunk->first_free = i; 6983d331ad7SAl Viro 699723ad1d9SAl Viro p = chunk->map + i; 700723ad1d9SAl Viro *p = off &= ~1; 701723ad1d9SAl Viro chunk->free_size += (p[1] & ~1) - off; 702fbf59bc9STejun Heo 703b539b87fSTejun Heo *occ_pages_p = pcpu_count_occupied_pages(chunk, i); 704b539b87fSTejun Heo 705fbf59bc9STejun Heo /* merge with next? */ 706723ad1d9SAl Viro if (!(p[1] & 1)) 707723ad1d9SAl Viro to_free++; 708723ad1d9SAl Viro /* merge with previous? */ 709723ad1d9SAl Viro if (i > 0 && !(p[-1] & 1)) { 710723ad1d9SAl Viro to_free++; 711723ad1d9SAl Viro i--; 712723ad1d9SAl Viro p--; 713723ad1d9SAl Viro } 714723ad1d9SAl Viro if (to_free) { 715723ad1d9SAl Viro chunk->map_used -= to_free; 716723ad1d9SAl Viro memmove(p + 1, p + 1 + to_free, 717723ad1d9SAl Viro (chunk->map_used - i) * sizeof(chunk->map[0])); 718fbf59bc9STejun Heo } 719fbf59bc9STejun Heo 720723ad1d9SAl Viro chunk->contig_hint = max(chunk->map[i + 1] - chunk->map[i] - 1, chunk->contig_hint); 721fbf59bc9STejun Heo pcpu_chunk_relocate(chunk, oslot); 722fbf59bc9STejun Heo } 723fbf59bc9STejun Heo 7246081089fSTejun Heo static struct pcpu_chunk *pcpu_alloc_chunk(void) 7256081089fSTejun Heo { 7266081089fSTejun Heo struct pcpu_chunk *chunk; 7276081089fSTejun Heo 72890459ce0SBob Liu chunk = pcpu_mem_zalloc(pcpu_chunk_struct_size); 7296081089fSTejun Heo if (!chunk) 7306081089fSTejun Heo return NULL; 7316081089fSTejun Heo 73290459ce0SBob Liu chunk->map = pcpu_mem_zalloc(PCPU_DFL_MAP_ALLOC * 73390459ce0SBob Liu sizeof(chunk->map[0])); 7346081089fSTejun Heo if (!chunk->map) { 7355a838c3bSJianyu Zhan pcpu_mem_free(chunk, pcpu_chunk_struct_size); 7366081089fSTejun Heo return NULL; 7376081089fSTejun Heo } 7386081089fSTejun Heo 7396081089fSTejun Heo chunk->map_alloc = PCPU_DFL_MAP_ALLOC; 740723ad1d9SAl Viro chunk->map[0] = 0; 741723ad1d9SAl Viro chunk->map[1] = pcpu_unit_size | 1; 742723ad1d9SAl Viro chunk->map_used = 1; 7436081089fSTejun Heo 7446081089fSTejun Heo INIT_LIST_HEAD(&chunk->list); 7459c824b6aSTejun Heo INIT_WORK(&chunk->map_extend_work, pcpu_map_extend_workfn); 7466081089fSTejun Heo chunk->free_size = pcpu_unit_size; 7476081089fSTejun Heo chunk->contig_hint = pcpu_unit_size; 7486081089fSTejun Heo 7496081089fSTejun Heo return chunk; 7506081089fSTejun Heo } 7516081089fSTejun Heo 7526081089fSTejun Heo static void pcpu_free_chunk(struct pcpu_chunk *chunk) 7536081089fSTejun Heo { 7546081089fSTejun Heo if (!chunk) 7556081089fSTejun Heo return; 7566081089fSTejun Heo pcpu_mem_free(chunk->map, chunk->map_alloc * sizeof(chunk->map[0])); 757b4916cb1SJoonsoo Kim pcpu_mem_free(chunk, pcpu_chunk_struct_size); 7586081089fSTejun Heo } 7596081089fSTejun Heo 760b539b87fSTejun Heo /** 761b539b87fSTejun Heo * pcpu_chunk_populated - post-population bookkeeping 762b539b87fSTejun Heo * @chunk: pcpu_chunk which got populated 763b539b87fSTejun Heo * @page_start: the start page 764b539b87fSTejun Heo * @page_end: the end page 765b539b87fSTejun Heo * 766b539b87fSTejun Heo * Pages in [@page_start,@page_end) have been populated to @chunk. Update 767b539b87fSTejun Heo * the bookkeeping information accordingly. Must be called after each 768b539b87fSTejun Heo * successful population. 769b539b87fSTejun Heo */ 770b539b87fSTejun Heo static void pcpu_chunk_populated(struct pcpu_chunk *chunk, 771b539b87fSTejun Heo int page_start, int page_end) 772b539b87fSTejun Heo { 773b539b87fSTejun Heo int nr = page_end - page_start; 774b539b87fSTejun Heo 775b539b87fSTejun Heo lockdep_assert_held(&pcpu_lock); 776b539b87fSTejun Heo 777b539b87fSTejun Heo bitmap_set(chunk->populated, page_start, nr); 778b539b87fSTejun Heo chunk->nr_populated += nr; 779b539b87fSTejun Heo pcpu_nr_empty_pop_pages += nr; 780b539b87fSTejun Heo } 781b539b87fSTejun Heo 782b539b87fSTejun Heo /** 783b539b87fSTejun Heo * pcpu_chunk_depopulated - post-depopulation bookkeeping 784b539b87fSTejun Heo * @chunk: pcpu_chunk which got depopulated 785b539b87fSTejun Heo * @page_start: the start page 786b539b87fSTejun Heo * @page_end: the end page 787b539b87fSTejun Heo * 788b539b87fSTejun Heo * Pages in [@page_start,@page_end) have been depopulated from @chunk. 789b539b87fSTejun Heo * Update the bookkeeping information accordingly. Must be called after 790b539b87fSTejun Heo * each successful depopulation. 791b539b87fSTejun Heo */ 792b539b87fSTejun Heo static void pcpu_chunk_depopulated(struct pcpu_chunk *chunk, 793b539b87fSTejun Heo int page_start, int page_end) 794b539b87fSTejun Heo { 795b539b87fSTejun Heo int nr = page_end - page_start; 796b539b87fSTejun Heo 797b539b87fSTejun Heo lockdep_assert_held(&pcpu_lock); 798b539b87fSTejun Heo 799b539b87fSTejun Heo bitmap_clear(chunk->populated, page_start, nr); 800b539b87fSTejun Heo chunk->nr_populated -= nr; 801b539b87fSTejun Heo pcpu_nr_empty_pop_pages -= nr; 802b539b87fSTejun Heo } 803b539b87fSTejun Heo 804fbf59bc9STejun Heo /* 8059f645532STejun Heo * Chunk management implementation. 806fbf59bc9STejun Heo * 8079f645532STejun Heo * To allow different implementations, chunk alloc/free and 8089f645532STejun Heo * [de]population are implemented in a separate file which is pulled 8099f645532STejun Heo * into this file and compiled together. The following functions 8109f645532STejun Heo * should be implemented. 811ccea34b5STejun Heo * 8129f645532STejun Heo * pcpu_populate_chunk - populate the specified range of a chunk 8139f645532STejun Heo * pcpu_depopulate_chunk - depopulate the specified range of a chunk 8149f645532STejun Heo * pcpu_create_chunk - create a new chunk 8159f645532STejun Heo * pcpu_destroy_chunk - destroy a chunk, always preceded by full depop 8169f645532STejun Heo * pcpu_addr_to_page - translate address to physical address 8179f645532STejun Heo * pcpu_verify_alloc_info - check alloc_info is acceptable during init 818fbf59bc9STejun Heo */ 8199f645532STejun Heo static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size); 8209f645532STejun Heo static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size); 8219f645532STejun Heo static struct pcpu_chunk *pcpu_create_chunk(void); 8229f645532STejun Heo static void pcpu_destroy_chunk(struct pcpu_chunk *chunk); 8239f645532STejun Heo static struct page *pcpu_addr_to_page(void *addr); 8249f645532STejun Heo static int __init pcpu_verify_alloc_info(const struct pcpu_alloc_info *ai); 825fbf59bc9STejun Heo 826b0c9778bSTejun Heo #ifdef CONFIG_NEED_PER_CPU_KM 827b0c9778bSTejun Heo #include "percpu-km.c" 828b0c9778bSTejun Heo #else 8299f645532STejun Heo #include "percpu-vm.c" 830b0c9778bSTejun Heo #endif 831fbf59bc9STejun Heo 832fbf59bc9STejun Heo /** 83388999a89STejun Heo * pcpu_chunk_addr_search - determine chunk containing specified address 83488999a89STejun Heo * @addr: address for which the chunk needs to be determined. 83588999a89STejun Heo * 83688999a89STejun Heo * RETURNS: 83788999a89STejun Heo * The address of the found chunk. 83888999a89STejun Heo */ 83988999a89STejun Heo static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr) 84088999a89STejun Heo { 84188999a89STejun Heo /* is it in the first chunk? */ 84288999a89STejun Heo if (pcpu_addr_in_first_chunk(addr)) { 84388999a89STejun Heo /* is it in the reserved area? */ 84488999a89STejun Heo if (pcpu_addr_in_reserved_chunk(addr)) 84588999a89STejun Heo return pcpu_reserved_chunk; 84688999a89STejun Heo return pcpu_first_chunk; 84788999a89STejun Heo } 84888999a89STejun Heo 84988999a89STejun Heo /* 85088999a89STejun Heo * The address is relative to unit0 which might be unused and 85188999a89STejun Heo * thus unmapped. Offset the address to the unit space of the 85288999a89STejun Heo * current processor before looking it up in the vmalloc 85388999a89STejun Heo * space. Note that any possible cpu id can be used here, so 85488999a89STejun Heo * there's no need to worry about preemption or cpu hotplug. 85588999a89STejun Heo */ 85688999a89STejun Heo addr += pcpu_unit_offsets[raw_smp_processor_id()]; 8579f645532STejun Heo return pcpu_get_page_chunk(pcpu_addr_to_page(addr)); 85888999a89STejun Heo } 85988999a89STejun Heo 86088999a89STejun Heo /** 861edcb4639STejun Heo * pcpu_alloc - the percpu allocator 862cae3aeb8STejun Heo * @size: size of area to allocate in bytes 863fbf59bc9STejun Heo * @align: alignment of area (max PAGE_SIZE) 864edcb4639STejun Heo * @reserved: allocate from the reserved chunk if available 8655835d96eSTejun Heo * @gfp: allocation flags 866fbf59bc9STejun Heo * 8675835d96eSTejun Heo * Allocate percpu area of @size bytes aligned at @align. If @gfp doesn't 8685835d96eSTejun Heo * contain %GFP_KERNEL, the allocation is atomic. 869fbf59bc9STejun Heo * 870fbf59bc9STejun Heo * RETURNS: 871fbf59bc9STejun Heo * Percpu pointer to the allocated area on success, NULL on failure. 872fbf59bc9STejun Heo */ 8735835d96eSTejun Heo static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved, 8745835d96eSTejun Heo gfp_t gfp) 875fbf59bc9STejun Heo { 876f2badb0cSTejun Heo static int warn_limit = 10; 877fbf59bc9STejun Heo struct pcpu_chunk *chunk; 878f2badb0cSTejun Heo const char *err; 8796ae833c7STejun Heo bool is_atomic = (gfp & GFP_KERNEL) != GFP_KERNEL; 880b539b87fSTejun Heo int occ_pages = 0; 881b38d08f3STejun Heo int slot, off, new_alloc, cpu, ret; 882403a91b1SJiri Kosina unsigned long flags; 883f528f0b8SCatalin Marinas void __percpu *ptr; 884fbf59bc9STejun Heo 885723ad1d9SAl Viro /* 886723ad1d9SAl Viro * We want the lowest bit of offset available for in-use/free 8872f69fa82SViro * indicator, so force >= 16bit alignment and make size even. 888723ad1d9SAl Viro */ 889723ad1d9SAl Viro if (unlikely(align < 2)) 890723ad1d9SAl Viro align = 2; 891723ad1d9SAl Viro 892fb009e3aSChristoph Lameter size = ALIGN(size, 2); 8932f69fa82SViro 8948d408b4bSTejun Heo if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE)) { 895fbf59bc9STejun Heo WARN(true, "illegal size (%zu) or align (%zu) for " 896fbf59bc9STejun Heo "percpu allocation\n", size, align); 897fbf59bc9STejun Heo return NULL; 898fbf59bc9STejun Heo } 899fbf59bc9STejun Heo 900403a91b1SJiri Kosina spin_lock_irqsave(&pcpu_lock, flags); 901fbf59bc9STejun Heo 902edcb4639STejun Heo /* serve reserved allocations from the reserved chunk if available */ 903edcb4639STejun Heo if (reserved && pcpu_reserved_chunk) { 904edcb4639STejun Heo chunk = pcpu_reserved_chunk; 905833af842STejun Heo 906833af842STejun Heo if (size > chunk->contig_hint) { 907833af842STejun Heo err = "alloc from reserved chunk failed"; 908ccea34b5STejun Heo goto fail_unlock; 909f2badb0cSTejun Heo } 910833af842STejun Heo 9119c824b6aSTejun Heo while ((new_alloc = pcpu_need_to_extend(chunk, is_atomic))) { 912833af842STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 9135835d96eSTejun Heo if (is_atomic || 9145835d96eSTejun Heo pcpu_extend_area_map(chunk, new_alloc) < 0) { 915833af842STejun Heo err = "failed to extend area map of reserved chunk"; 916b38d08f3STejun Heo goto fail; 917833af842STejun Heo } 918833af842STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 919833af842STejun Heo } 920833af842STejun Heo 921b539b87fSTejun Heo off = pcpu_alloc_area(chunk, size, align, is_atomic, 922b539b87fSTejun Heo &occ_pages); 923edcb4639STejun Heo if (off >= 0) 924edcb4639STejun Heo goto area_found; 925833af842STejun Heo 926f2badb0cSTejun Heo err = "alloc from reserved chunk failed"; 927ccea34b5STejun Heo goto fail_unlock; 928edcb4639STejun Heo } 929edcb4639STejun Heo 930ccea34b5STejun Heo restart: 931edcb4639STejun Heo /* search through normal chunks */ 932fbf59bc9STejun Heo for (slot = pcpu_size_to_slot(size); slot < pcpu_nr_slots; slot++) { 933fbf59bc9STejun Heo list_for_each_entry(chunk, &pcpu_slot[slot], list) { 934fbf59bc9STejun Heo if (size > chunk->contig_hint) 935fbf59bc9STejun Heo continue; 936ccea34b5STejun Heo 9379c824b6aSTejun Heo new_alloc = pcpu_need_to_extend(chunk, is_atomic); 938833af842STejun Heo if (new_alloc) { 9395835d96eSTejun Heo if (is_atomic) 9405835d96eSTejun Heo continue; 941833af842STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 942833af842STejun Heo if (pcpu_extend_area_map(chunk, 943833af842STejun Heo new_alloc) < 0) { 944f2badb0cSTejun Heo err = "failed to extend area map"; 945b38d08f3STejun Heo goto fail; 946833af842STejun Heo } 947833af842STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 948833af842STejun Heo /* 949833af842STejun Heo * pcpu_lock has been dropped, need to 950833af842STejun Heo * restart cpu_slot list walking. 951833af842STejun Heo */ 952833af842STejun Heo goto restart; 953ccea34b5STejun Heo } 954ccea34b5STejun Heo 955b539b87fSTejun Heo off = pcpu_alloc_area(chunk, size, align, is_atomic, 956b539b87fSTejun Heo &occ_pages); 957fbf59bc9STejun Heo if (off >= 0) 958fbf59bc9STejun Heo goto area_found; 959fbf59bc9STejun Heo } 960fbf59bc9STejun Heo } 961fbf59bc9STejun Heo 962403a91b1SJiri Kosina spin_unlock_irqrestore(&pcpu_lock, flags); 963ccea34b5STejun Heo 964b38d08f3STejun Heo /* 965b38d08f3STejun Heo * No space left. Create a new chunk. We don't want multiple 966b38d08f3STejun Heo * tasks to create chunks simultaneously. Serialize and create iff 967b38d08f3STejun Heo * there's still no empty chunk after grabbing the mutex. 968b38d08f3STejun Heo */ 9695835d96eSTejun Heo if (is_atomic) 9705835d96eSTejun Heo goto fail; 9715835d96eSTejun Heo 972b38d08f3STejun Heo mutex_lock(&pcpu_alloc_mutex); 973b38d08f3STejun Heo 974b38d08f3STejun Heo if (list_empty(&pcpu_slot[pcpu_nr_slots - 1])) { 9756081089fSTejun Heo chunk = pcpu_create_chunk(); 976f2badb0cSTejun Heo if (!chunk) { 97723cb8981STejun Heo mutex_unlock(&pcpu_alloc_mutex); 978f2badb0cSTejun Heo err = "failed to allocate new chunk"; 979b38d08f3STejun Heo goto fail; 980f2badb0cSTejun Heo } 981ccea34b5STejun Heo 982403a91b1SJiri Kosina spin_lock_irqsave(&pcpu_lock, flags); 983fbf59bc9STejun Heo pcpu_chunk_relocate(chunk, -1); 984b38d08f3STejun Heo } else { 985b38d08f3STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 986b38d08f3STejun Heo } 987b38d08f3STejun Heo 988b38d08f3STejun Heo mutex_unlock(&pcpu_alloc_mutex); 989ccea34b5STejun Heo goto restart; 990fbf59bc9STejun Heo 991fbf59bc9STejun Heo area_found: 992403a91b1SJiri Kosina spin_unlock_irqrestore(&pcpu_lock, flags); 993ccea34b5STejun Heo 994dca49645STejun Heo /* populate if not all pages are already there */ 9955835d96eSTejun Heo if (!is_atomic) { 996e04d3208STejun Heo int page_start, page_end, rs, re; 997e04d3208STejun Heo 998b38d08f3STejun Heo mutex_lock(&pcpu_alloc_mutex); 999e04d3208STejun Heo 1000dca49645STejun Heo page_start = PFN_DOWN(off); 1001dca49645STejun Heo page_end = PFN_UP(off + size); 1002dca49645STejun Heo 1003a93ace48STejun Heo pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) { 1004dca49645STejun Heo WARN_ON(chunk->immutable); 1005dca49645STejun Heo 1006b38d08f3STejun Heo ret = pcpu_populate_chunk(chunk, rs, re); 1007b38d08f3STejun Heo 1008403a91b1SJiri Kosina spin_lock_irqsave(&pcpu_lock, flags); 1009b38d08f3STejun Heo if (ret) { 1010b38d08f3STejun Heo mutex_unlock(&pcpu_alloc_mutex); 1011b539b87fSTejun Heo pcpu_free_area(chunk, off, &occ_pages); 1012f2badb0cSTejun Heo err = "failed to populate"; 1013ccea34b5STejun Heo goto fail_unlock; 1014fbf59bc9STejun Heo } 1015b539b87fSTejun Heo pcpu_chunk_populated(chunk, rs, re); 1016b38d08f3STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 1017dca49645STejun Heo } 1018dca49645STejun Heo 1019ccea34b5STejun Heo mutex_unlock(&pcpu_alloc_mutex); 1020e04d3208STejun Heo } 1021ccea34b5STejun Heo 1022b539b87fSTejun Heo if (chunk != pcpu_reserved_chunk) 1023b539b87fSTejun Heo pcpu_nr_empty_pop_pages -= occ_pages; 1024b539b87fSTejun Heo 10251a4d7607STejun Heo if (pcpu_nr_empty_pop_pages < PCPU_EMPTY_POP_PAGES_LOW) 10261a4d7607STejun Heo pcpu_schedule_balance_work(); 10271a4d7607STejun Heo 1028dca49645STejun Heo /* clear the areas and return address relative to base address */ 1029dca49645STejun Heo for_each_possible_cpu(cpu) 1030dca49645STejun Heo memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size); 1031dca49645STejun Heo 1032f528f0b8SCatalin Marinas ptr = __addr_to_pcpu_ptr(chunk->base_addr + off); 1033f528f0b8SCatalin Marinas kmemleak_alloc_percpu(ptr, size); 1034f528f0b8SCatalin Marinas return ptr; 1035ccea34b5STejun Heo 1036ccea34b5STejun Heo fail_unlock: 1037403a91b1SJiri Kosina spin_unlock_irqrestore(&pcpu_lock, flags); 1038b38d08f3STejun Heo fail: 10395835d96eSTejun Heo if (!is_atomic && warn_limit) { 10405835d96eSTejun Heo pr_warning("PERCPU: 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) 1044f2badb0cSTejun Heo pr_info("PERCPU: 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(); 10501a4d7607STejun Heo } 1051ccea34b5STejun Heo return NULL; 1052fbf59bc9STejun Heo } 1053edcb4639STejun Heo 1054edcb4639STejun Heo /** 10555835d96eSTejun Heo * __alloc_percpu_gfp - allocate dynamic percpu area 1056edcb4639STejun Heo * @size: size of area to allocate in bytes 1057edcb4639STejun Heo * @align: alignment of area (max PAGE_SIZE) 10585835d96eSTejun Heo * @gfp: allocation flags 1059edcb4639STejun Heo * 10605835d96eSTejun Heo * Allocate zero-filled percpu area of @size bytes aligned at @align. If 10615835d96eSTejun Heo * @gfp doesn't contain %GFP_KERNEL, the allocation doesn't block and can 10625835d96eSTejun Heo * be called from any context but is a lot more likely to fail. 1063ccea34b5STejun Heo * 1064edcb4639STejun Heo * RETURNS: 1065edcb4639STejun Heo * Percpu pointer to the allocated area on success, NULL on failure. 1066edcb4639STejun Heo */ 10675835d96eSTejun Heo void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp) 10685835d96eSTejun Heo { 10695835d96eSTejun Heo return pcpu_alloc(size, align, false, gfp); 10705835d96eSTejun Heo } 10715835d96eSTejun Heo EXPORT_SYMBOL_GPL(__alloc_percpu_gfp); 10725835d96eSTejun Heo 10735835d96eSTejun Heo /** 10745835d96eSTejun Heo * __alloc_percpu - allocate dynamic percpu area 10755835d96eSTejun Heo * @size: size of area to allocate in bytes 10765835d96eSTejun Heo * @align: alignment of area (max PAGE_SIZE) 10775835d96eSTejun Heo * 10785835d96eSTejun Heo * Equivalent to __alloc_percpu_gfp(size, align, %GFP_KERNEL). 10795835d96eSTejun Heo */ 108043cf38ebSTejun Heo void __percpu *__alloc_percpu(size_t size, size_t align) 1081edcb4639STejun Heo { 10825835d96eSTejun Heo return pcpu_alloc(size, align, false, GFP_KERNEL); 1083edcb4639STejun Heo } 1084fbf59bc9STejun Heo EXPORT_SYMBOL_GPL(__alloc_percpu); 1085fbf59bc9STejun Heo 1086edcb4639STejun Heo /** 1087edcb4639STejun Heo * __alloc_reserved_percpu - allocate reserved percpu area 1088edcb4639STejun Heo * @size: size of area to allocate in bytes 1089edcb4639STejun Heo * @align: alignment of area (max PAGE_SIZE) 1090edcb4639STejun Heo * 10919329ba97STejun Heo * Allocate zero-filled percpu area of @size bytes aligned at @align 10929329ba97STejun Heo * from reserved percpu area if arch has set it up; otherwise, 10939329ba97STejun Heo * allocation is served from the same dynamic area. Might sleep. 10949329ba97STejun Heo * Might trigger writeouts. 1095edcb4639STejun Heo * 1096ccea34b5STejun Heo * CONTEXT: 1097ccea34b5STejun Heo * Does GFP_KERNEL allocation. 1098ccea34b5STejun Heo * 1099edcb4639STejun Heo * RETURNS: 1100edcb4639STejun Heo * Percpu pointer to the allocated area on success, NULL on failure. 1101edcb4639STejun Heo */ 110243cf38ebSTejun Heo void __percpu *__alloc_reserved_percpu(size_t size, size_t align) 1103edcb4639STejun Heo { 11045835d96eSTejun Heo return pcpu_alloc(size, align, true, GFP_KERNEL); 1105edcb4639STejun Heo } 1106edcb4639STejun Heo 1107a56dbddfSTejun Heo /** 11081a4d7607STejun Heo * pcpu_balance_workfn - manage the amount of free chunks and populated pages 1109a56dbddfSTejun Heo * @work: unused 1110a56dbddfSTejun Heo * 1111a56dbddfSTejun Heo * Reclaim all fully free chunks except for the first one. 1112a56dbddfSTejun Heo */ 1113fe6bd8c3STejun Heo static void pcpu_balance_workfn(struct work_struct *work) 1114fbf59bc9STejun Heo { 1115fe6bd8c3STejun Heo LIST_HEAD(to_free); 1116fe6bd8c3STejun Heo struct list_head *free_head = &pcpu_slot[pcpu_nr_slots - 1]; 1117a56dbddfSTejun Heo struct pcpu_chunk *chunk, *next; 11181a4d7607STejun Heo int slot, nr_to_pop, ret; 1119a56dbddfSTejun Heo 11201a4d7607STejun Heo /* 11211a4d7607STejun Heo * There's no reason to keep around multiple unused chunks and VM 11221a4d7607STejun Heo * areas can be scarce. Destroy all free chunks except for one. 11231a4d7607STejun Heo */ 1124ccea34b5STejun Heo mutex_lock(&pcpu_alloc_mutex); 1125ccea34b5STejun Heo spin_lock_irq(&pcpu_lock); 1126a56dbddfSTejun Heo 1127fe6bd8c3STejun Heo list_for_each_entry_safe(chunk, next, free_head, list) { 11288d408b4bSTejun Heo WARN_ON(chunk->immutable); 1129a56dbddfSTejun Heo 1130a56dbddfSTejun Heo /* spare the first one */ 1131fe6bd8c3STejun Heo if (chunk == list_first_entry(free_head, struct pcpu_chunk, list)) 1132a56dbddfSTejun Heo continue; 1133a56dbddfSTejun Heo 1134fe6bd8c3STejun Heo list_move(&chunk->list, &to_free); 1135a56dbddfSTejun Heo } 1136a56dbddfSTejun Heo 1137ccea34b5STejun Heo spin_unlock_irq(&pcpu_lock); 1138a56dbddfSTejun Heo 1139fe6bd8c3STejun Heo list_for_each_entry_safe(chunk, next, &to_free, list) { 1140a93ace48STejun Heo int rs, re; 1141dca49645STejun Heo 1142a93ace48STejun Heo pcpu_for_each_pop_region(chunk, rs, re, 0, pcpu_unit_pages) { 1143a93ace48STejun Heo pcpu_depopulate_chunk(chunk, rs, re); 1144b539b87fSTejun Heo spin_lock_irq(&pcpu_lock); 1145b539b87fSTejun Heo pcpu_chunk_depopulated(chunk, rs, re); 1146b539b87fSTejun Heo spin_unlock_irq(&pcpu_lock); 1147a93ace48STejun Heo } 11486081089fSTejun Heo pcpu_destroy_chunk(chunk); 1149fbf59bc9STejun Heo } 1150971f3918STejun Heo 11511a4d7607STejun Heo /* 11521a4d7607STejun Heo * Ensure there are certain number of free populated pages for 11531a4d7607STejun Heo * atomic allocs. Fill up from the most packed so that atomic 11541a4d7607STejun Heo * allocs don't increase fragmentation. If atomic allocation 11551a4d7607STejun Heo * failed previously, always populate the maximum amount. This 11561a4d7607STejun Heo * should prevent atomic allocs larger than PAGE_SIZE from keeping 11571a4d7607STejun Heo * failing indefinitely; however, large atomic allocs are not 11581a4d7607STejun Heo * something we support properly and can be highly unreliable and 11591a4d7607STejun Heo * inefficient. 11601a4d7607STejun Heo */ 11611a4d7607STejun Heo retry_pop: 11621a4d7607STejun Heo if (pcpu_atomic_alloc_failed) { 11631a4d7607STejun Heo nr_to_pop = PCPU_EMPTY_POP_PAGES_HIGH; 11641a4d7607STejun Heo /* best effort anyway, don't worry about synchronization */ 11651a4d7607STejun Heo pcpu_atomic_alloc_failed = false; 11661a4d7607STejun Heo } else { 11671a4d7607STejun Heo nr_to_pop = clamp(PCPU_EMPTY_POP_PAGES_HIGH - 11681a4d7607STejun Heo pcpu_nr_empty_pop_pages, 11691a4d7607STejun Heo 0, PCPU_EMPTY_POP_PAGES_HIGH); 11701a4d7607STejun Heo } 11711a4d7607STejun Heo 11721a4d7607STejun Heo for (slot = pcpu_size_to_slot(PAGE_SIZE); slot < pcpu_nr_slots; slot++) { 11731a4d7607STejun Heo int nr_unpop = 0, rs, re; 11741a4d7607STejun Heo 11751a4d7607STejun Heo if (!nr_to_pop) 11761a4d7607STejun Heo break; 11771a4d7607STejun Heo 11781a4d7607STejun Heo spin_lock_irq(&pcpu_lock); 11791a4d7607STejun Heo list_for_each_entry(chunk, &pcpu_slot[slot], list) { 11801a4d7607STejun Heo nr_unpop = pcpu_unit_pages - chunk->nr_populated; 11811a4d7607STejun Heo if (nr_unpop) 11821a4d7607STejun Heo break; 11831a4d7607STejun Heo } 11841a4d7607STejun Heo spin_unlock_irq(&pcpu_lock); 11851a4d7607STejun Heo 11861a4d7607STejun Heo if (!nr_unpop) 11871a4d7607STejun Heo continue; 11881a4d7607STejun Heo 11891a4d7607STejun Heo /* @chunk can't go away while pcpu_alloc_mutex is held */ 11901a4d7607STejun Heo pcpu_for_each_unpop_region(chunk, rs, re, 0, pcpu_unit_pages) { 11911a4d7607STejun Heo int nr = min(re - rs, nr_to_pop); 11921a4d7607STejun Heo 11931a4d7607STejun Heo ret = pcpu_populate_chunk(chunk, rs, rs + nr); 11941a4d7607STejun Heo if (!ret) { 11951a4d7607STejun Heo nr_to_pop -= nr; 11961a4d7607STejun Heo spin_lock_irq(&pcpu_lock); 11971a4d7607STejun Heo pcpu_chunk_populated(chunk, rs, rs + nr); 11981a4d7607STejun Heo spin_unlock_irq(&pcpu_lock); 11991a4d7607STejun Heo } else { 12001a4d7607STejun Heo nr_to_pop = 0; 12011a4d7607STejun Heo } 12021a4d7607STejun Heo 12031a4d7607STejun Heo if (!nr_to_pop) 12041a4d7607STejun Heo break; 12051a4d7607STejun Heo } 12061a4d7607STejun Heo } 12071a4d7607STejun Heo 12081a4d7607STejun Heo if (nr_to_pop) { 12091a4d7607STejun Heo /* ran out of chunks to populate, create a new one and retry */ 12101a4d7607STejun Heo chunk = pcpu_create_chunk(); 12111a4d7607STejun Heo if (chunk) { 12121a4d7607STejun Heo spin_lock_irq(&pcpu_lock); 12131a4d7607STejun Heo pcpu_chunk_relocate(chunk, -1); 12141a4d7607STejun Heo spin_unlock_irq(&pcpu_lock); 12151a4d7607STejun Heo goto retry_pop; 12161a4d7607STejun Heo } 12171a4d7607STejun Heo } 12181a4d7607STejun Heo 1219971f3918STejun Heo mutex_unlock(&pcpu_alloc_mutex); 1220a56dbddfSTejun Heo } 1221fbf59bc9STejun Heo 1222fbf59bc9STejun Heo /** 1223fbf59bc9STejun Heo * free_percpu - free percpu area 1224fbf59bc9STejun Heo * @ptr: pointer to area to free 1225fbf59bc9STejun Heo * 1226ccea34b5STejun Heo * Free percpu area @ptr. 1227ccea34b5STejun Heo * 1228ccea34b5STejun Heo * CONTEXT: 1229ccea34b5STejun Heo * Can be called from atomic context. 1230fbf59bc9STejun Heo */ 123143cf38ebSTejun Heo void free_percpu(void __percpu *ptr) 1232fbf59bc9STejun Heo { 1233129182e5SAndrew Morton void *addr; 1234fbf59bc9STejun Heo struct pcpu_chunk *chunk; 1235ccea34b5STejun Heo unsigned long flags; 1236b539b87fSTejun Heo int off, occ_pages; 1237fbf59bc9STejun Heo 1238fbf59bc9STejun Heo if (!ptr) 1239fbf59bc9STejun Heo return; 1240fbf59bc9STejun Heo 1241f528f0b8SCatalin Marinas kmemleak_free_percpu(ptr); 1242f528f0b8SCatalin Marinas 1243129182e5SAndrew Morton addr = __pcpu_ptr_to_addr(ptr); 1244129182e5SAndrew Morton 1245ccea34b5STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 1246fbf59bc9STejun Heo 1247fbf59bc9STejun Heo chunk = pcpu_chunk_addr_search(addr); 1248bba174f5STejun Heo off = addr - chunk->base_addr; 1249fbf59bc9STejun Heo 1250b539b87fSTejun Heo pcpu_free_area(chunk, off, &occ_pages); 1251b539b87fSTejun Heo 1252b539b87fSTejun Heo if (chunk != pcpu_reserved_chunk) 1253b539b87fSTejun Heo pcpu_nr_empty_pop_pages += occ_pages; 1254fbf59bc9STejun Heo 1255a56dbddfSTejun Heo /* if there are more than one fully free chunks, wake up grim reaper */ 1256fbf59bc9STejun Heo if (chunk->free_size == pcpu_unit_size) { 1257fbf59bc9STejun Heo struct pcpu_chunk *pos; 1258fbf59bc9STejun Heo 1259a56dbddfSTejun Heo list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list) 1260fbf59bc9STejun Heo if (pos != chunk) { 12611a4d7607STejun Heo pcpu_schedule_balance_work(); 1262fbf59bc9STejun Heo break; 1263fbf59bc9STejun Heo } 1264fbf59bc9STejun Heo } 1265fbf59bc9STejun Heo 1266ccea34b5STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 1267fbf59bc9STejun Heo } 1268fbf59bc9STejun Heo EXPORT_SYMBOL_GPL(free_percpu); 1269fbf59bc9STejun Heo 12703b034b0dSVivek Goyal /** 127110fad5e4STejun Heo * is_kernel_percpu_address - test whether address is from static percpu area 127210fad5e4STejun Heo * @addr: address to test 127310fad5e4STejun Heo * 127410fad5e4STejun Heo * Test whether @addr belongs to in-kernel static percpu area. Module 127510fad5e4STejun Heo * static percpu areas are not considered. For those, use 127610fad5e4STejun Heo * is_module_percpu_address(). 127710fad5e4STejun Heo * 127810fad5e4STejun Heo * RETURNS: 127910fad5e4STejun Heo * %true if @addr is from in-kernel static percpu area, %false otherwise. 128010fad5e4STejun Heo */ 128110fad5e4STejun Heo bool is_kernel_percpu_address(unsigned long addr) 128210fad5e4STejun Heo { 1283bbddff05STejun Heo #ifdef CONFIG_SMP 128410fad5e4STejun Heo const size_t static_size = __per_cpu_end - __per_cpu_start; 128510fad5e4STejun Heo void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr); 128610fad5e4STejun Heo unsigned int cpu; 128710fad5e4STejun Heo 128810fad5e4STejun Heo for_each_possible_cpu(cpu) { 128910fad5e4STejun Heo void *start = per_cpu_ptr(base, cpu); 129010fad5e4STejun Heo 129110fad5e4STejun Heo if ((void *)addr >= start && (void *)addr < start + static_size) 129210fad5e4STejun Heo return true; 129310fad5e4STejun Heo } 1294bbddff05STejun Heo #endif 1295bbddff05STejun Heo /* on UP, can't distinguish from other static vars, always false */ 129610fad5e4STejun Heo return false; 129710fad5e4STejun Heo } 129810fad5e4STejun Heo 129910fad5e4STejun Heo /** 13003b034b0dSVivek Goyal * per_cpu_ptr_to_phys - convert translated percpu address to physical address 13013b034b0dSVivek Goyal * @addr: the address to be converted to physical address 13023b034b0dSVivek Goyal * 13033b034b0dSVivek Goyal * Given @addr which is dereferenceable address obtained via one of 13043b034b0dSVivek Goyal * percpu access macros, this function translates it into its physical 13053b034b0dSVivek Goyal * address. The caller is responsible for ensuring @addr stays valid 13063b034b0dSVivek Goyal * until this function finishes. 13073b034b0dSVivek Goyal * 130867589c71SDave Young * percpu allocator has special setup for the first chunk, which currently 130967589c71SDave Young * supports either embedding in linear address space or vmalloc mapping, 131067589c71SDave Young * and, from the second one, the backing allocator (currently either vm or 131167589c71SDave Young * km) provides translation. 131267589c71SDave Young * 131367589c71SDave Young * The addr can be tranlated simply without checking if it falls into the 131467589c71SDave Young * first chunk. But the current code reflects better how percpu allocator 131567589c71SDave Young * actually works, and the verification can discover both bugs in percpu 131667589c71SDave Young * allocator itself and per_cpu_ptr_to_phys() callers. So we keep current 131767589c71SDave Young * code. 131867589c71SDave Young * 13193b034b0dSVivek Goyal * RETURNS: 13203b034b0dSVivek Goyal * The physical address for @addr. 13213b034b0dSVivek Goyal */ 13223b034b0dSVivek Goyal phys_addr_t per_cpu_ptr_to_phys(void *addr) 13233b034b0dSVivek Goyal { 13249983b6f0STejun Heo void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr); 13259983b6f0STejun Heo bool in_first_chunk = false; 1326a855b84cSTejun Heo unsigned long first_low, first_high; 13279983b6f0STejun Heo unsigned int cpu; 13289983b6f0STejun Heo 13299983b6f0STejun Heo /* 1330a855b84cSTejun Heo * The following test on unit_low/high isn't strictly 13319983b6f0STejun Heo * necessary but will speed up lookups of addresses which 13329983b6f0STejun Heo * aren't in the first chunk. 13339983b6f0STejun Heo */ 1334a855b84cSTejun Heo first_low = pcpu_chunk_addr(pcpu_first_chunk, pcpu_low_unit_cpu, 0); 1335a855b84cSTejun Heo first_high = pcpu_chunk_addr(pcpu_first_chunk, pcpu_high_unit_cpu, 13369983b6f0STejun Heo pcpu_unit_pages); 1337a855b84cSTejun Heo if ((unsigned long)addr >= first_low && 1338a855b84cSTejun Heo (unsigned long)addr < first_high) { 13399983b6f0STejun Heo for_each_possible_cpu(cpu) { 13409983b6f0STejun Heo void *start = per_cpu_ptr(base, cpu); 13419983b6f0STejun Heo 13429983b6f0STejun Heo if (addr >= start && addr < start + pcpu_unit_size) { 13439983b6f0STejun Heo in_first_chunk = true; 13449983b6f0STejun Heo break; 13459983b6f0STejun Heo } 13469983b6f0STejun Heo } 13479983b6f0STejun Heo } 13489983b6f0STejun Heo 13499983b6f0STejun Heo if (in_first_chunk) { 1350eac522efSDavid Howells if (!is_vmalloc_addr(addr)) 13513b034b0dSVivek Goyal return __pa(addr); 13523b034b0dSVivek Goyal else 13539f57bd4dSEugene Surovegin return page_to_phys(vmalloc_to_page(addr)) + 13549f57bd4dSEugene Surovegin offset_in_page(addr); 1355020ec653STejun Heo } else 13569f57bd4dSEugene Surovegin return page_to_phys(pcpu_addr_to_page(addr)) + 13579f57bd4dSEugene Surovegin offset_in_page(addr); 13583b034b0dSVivek Goyal } 13593b034b0dSVivek Goyal 1360fbf59bc9STejun Heo /** 1361fd1e8a1fSTejun Heo * pcpu_alloc_alloc_info - allocate percpu allocation info 1362fd1e8a1fSTejun Heo * @nr_groups: the number of groups 1363fd1e8a1fSTejun Heo * @nr_units: the number of units 1364033e48fbSTejun Heo * 1365fd1e8a1fSTejun Heo * Allocate ai which is large enough for @nr_groups groups containing 1366fd1e8a1fSTejun Heo * @nr_units units. The returned ai's groups[0].cpu_map points to the 1367fd1e8a1fSTejun Heo * cpu_map array which is long enough for @nr_units and filled with 1368fd1e8a1fSTejun Heo * NR_CPUS. It's the caller's responsibility to initialize cpu_map 1369fd1e8a1fSTejun Heo * pointer of other groups. 1370033e48fbSTejun Heo * 1371033e48fbSTejun Heo * RETURNS: 1372fd1e8a1fSTejun Heo * Pointer to the allocated pcpu_alloc_info on success, NULL on 1373fd1e8a1fSTejun Heo * failure. 1374033e48fbSTejun Heo */ 1375fd1e8a1fSTejun Heo struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, 1376fd1e8a1fSTejun Heo int nr_units) 1377fd1e8a1fSTejun Heo { 1378fd1e8a1fSTejun Heo struct pcpu_alloc_info *ai; 1379fd1e8a1fSTejun Heo size_t base_size, ai_size; 1380fd1e8a1fSTejun Heo void *ptr; 1381fd1e8a1fSTejun Heo int unit; 1382fd1e8a1fSTejun Heo 1383fd1e8a1fSTejun Heo base_size = ALIGN(sizeof(*ai) + nr_groups * sizeof(ai->groups[0]), 1384fd1e8a1fSTejun Heo __alignof__(ai->groups[0].cpu_map[0])); 1385fd1e8a1fSTejun Heo ai_size = base_size + nr_units * sizeof(ai->groups[0].cpu_map[0]); 1386fd1e8a1fSTejun Heo 1387999c17e3SSantosh Shilimkar ptr = memblock_virt_alloc_nopanic(PFN_ALIGN(ai_size), 0); 1388fd1e8a1fSTejun Heo if (!ptr) 1389fd1e8a1fSTejun Heo return NULL; 1390fd1e8a1fSTejun Heo ai = ptr; 1391fd1e8a1fSTejun Heo ptr += base_size; 1392fd1e8a1fSTejun Heo 1393fd1e8a1fSTejun Heo ai->groups[0].cpu_map = ptr; 1394fd1e8a1fSTejun Heo 1395fd1e8a1fSTejun Heo for (unit = 0; unit < nr_units; unit++) 1396fd1e8a1fSTejun Heo ai->groups[0].cpu_map[unit] = NR_CPUS; 1397fd1e8a1fSTejun Heo 1398fd1e8a1fSTejun Heo ai->nr_groups = nr_groups; 1399fd1e8a1fSTejun Heo ai->__ai_size = PFN_ALIGN(ai_size); 1400fd1e8a1fSTejun Heo 1401fd1e8a1fSTejun Heo return ai; 1402fd1e8a1fSTejun Heo } 1403fd1e8a1fSTejun Heo 1404fd1e8a1fSTejun Heo /** 1405fd1e8a1fSTejun Heo * pcpu_free_alloc_info - free percpu allocation info 1406fd1e8a1fSTejun Heo * @ai: pcpu_alloc_info to free 1407fd1e8a1fSTejun Heo * 1408fd1e8a1fSTejun Heo * Free @ai which was allocated by pcpu_alloc_alloc_info(). 1409fd1e8a1fSTejun Heo */ 1410fd1e8a1fSTejun Heo void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai) 1411fd1e8a1fSTejun Heo { 1412999c17e3SSantosh Shilimkar memblock_free_early(__pa(ai), ai->__ai_size); 1413fd1e8a1fSTejun Heo } 1414fd1e8a1fSTejun Heo 1415fd1e8a1fSTejun Heo /** 1416fd1e8a1fSTejun Heo * pcpu_dump_alloc_info - print out information about pcpu_alloc_info 1417fd1e8a1fSTejun Heo * @lvl: loglevel 1418fd1e8a1fSTejun Heo * @ai: allocation info to dump 1419fd1e8a1fSTejun Heo * 1420fd1e8a1fSTejun Heo * Print out information about @ai using loglevel @lvl. 1421fd1e8a1fSTejun Heo */ 1422fd1e8a1fSTejun Heo static void pcpu_dump_alloc_info(const char *lvl, 1423fd1e8a1fSTejun Heo const struct pcpu_alloc_info *ai) 1424033e48fbSTejun Heo { 1425fd1e8a1fSTejun Heo int group_width = 1, cpu_width = 1, width; 1426033e48fbSTejun Heo char empty_str[] = "--------"; 1427fd1e8a1fSTejun Heo int alloc = 0, alloc_end = 0; 1428fd1e8a1fSTejun Heo int group, v; 1429fd1e8a1fSTejun Heo int upa, apl; /* units per alloc, allocs per line */ 1430033e48fbSTejun Heo 1431fd1e8a1fSTejun Heo v = ai->nr_groups; 1432033e48fbSTejun Heo while (v /= 10) 1433fd1e8a1fSTejun Heo group_width++; 1434033e48fbSTejun Heo 1435fd1e8a1fSTejun Heo v = num_possible_cpus(); 1436fd1e8a1fSTejun Heo while (v /= 10) 1437fd1e8a1fSTejun Heo cpu_width++; 1438fd1e8a1fSTejun Heo empty_str[min_t(int, cpu_width, sizeof(empty_str) - 1)] = '\0'; 1439033e48fbSTejun Heo 1440fd1e8a1fSTejun Heo upa = ai->alloc_size / ai->unit_size; 1441fd1e8a1fSTejun Heo width = upa * (cpu_width + 1) + group_width + 3; 1442fd1e8a1fSTejun Heo apl = rounddown_pow_of_two(max(60 / width, 1)); 1443033e48fbSTejun Heo 1444fd1e8a1fSTejun Heo printk("%spcpu-alloc: s%zu r%zu d%zu u%zu alloc=%zu*%zu", 1445fd1e8a1fSTejun Heo lvl, ai->static_size, ai->reserved_size, ai->dyn_size, 1446fd1e8a1fSTejun Heo ai->unit_size, ai->alloc_size / ai->atom_size, ai->atom_size); 1447fd1e8a1fSTejun Heo 1448fd1e8a1fSTejun Heo for (group = 0; group < ai->nr_groups; group++) { 1449fd1e8a1fSTejun Heo const struct pcpu_group_info *gi = &ai->groups[group]; 1450fd1e8a1fSTejun Heo int unit = 0, unit_end = 0; 1451fd1e8a1fSTejun Heo 1452fd1e8a1fSTejun Heo BUG_ON(gi->nr_units % upa); 1453fd1e8a1fSTejun Heo for (alloc_end += gi->nr_units / upa; 1454fd1e8a1fSTejun Heo alloc < alloc_end; alloc++) { 1455fd1e8a1fSTejun Heo if (!(alloc % apl)) { 1456cb129820STejun Heo printk(KERN_CONT "\n"); 1457fd1e8a1fSTejun Heo printk("%spcpu-alloc: ", lvl); 1458033e48fbSTejun Heo } 1459cb129820STejun Heo printk(KERN_CONT "[%0*d] ", group_width, group); 1460fd1e8a1fSTejun Heo 1461fd1e8a1fSTejun Heo for (unit_end += upa; unit < unit_end; unit++) 1462fd1e8a1fSTejun Heo if (gi->cpu_map[unit] != NR_CPUS) 1463cb129820STejun Heo printk(KERN_CONT "%0*d ", cpu_width, 1464fd1e8a1fSTejun Heo gi->cpu_map[unit]); 1465033e48fbSTejun Heo else 1466cb129820STejun Heo printk(KERN_CONT "%s ", empty_str); 1467033e48fbSTejun Heo } 1468fd1e8a1fSTejun Heo } 1469cb129820STejun Heo printk(KERN_CONT "\n"); 1470033e48fbSTejun Heo } 1471033e48fbSTejun Heo 1472fbf59bc9STejun Heo /** 14738d408b4bSTejun Heo * pcpu_setup_first_chunk - initialize the first percpu chunk 1474fd1e8a1fSTejun Heo * @ai: pcpu_alloc_info describing how to percpu area is shaped 147538a6be52STejun Heo * @base_addr: mapped address 1476fbf59bc9STejun Heo * 14778d408b4bSTejun Heo * Initialize the first percpu chunk which contains the kernel static 14788d408b4bSTejun Heo * perpcu area. This function is to be called from arch percpu area 147938a6be52STejun Heo * setup path. 14808d408b4bSTejun Heo * 1481fd1e8a1fSTejun Heo * @ai contains all information necessary to initialize the first 1482fd1e8a1fSTejun Heo * chunk and prime the dynamic percpu allocator. 14838d408b4bSTejun Heo * 1484fd1e8a1fSTejun Heo * @ai->static_size is the size of static percpu area. 1485fd1e8a1fSTejun Heo * 1486fd1e8a1fSTejun Heo * @ai->reserved_size, if non-zero, specifies the amount of bytes to 1487edcb4639STejun Heo * reserve after the static area in the first chunk. This reserves 1488edcb4639STejun Heo * the first chunk such that it's available only through reserved 1489edcb4639STejun Heo * percpu allocation. This is primarily used to serve module percpu 1490edcb4639STejun Heo * static areas on architectures where the addressing model has 1491edcb4639STejun Heo * limited offset range for symbol relocations to guarantee module 1492edcb4639STejun Heo * percpu symbols fall inside the relocatable range. 1493edcb4639STejun Heo * 1494fd1e8a1fSTejun Heo * @ai->dyn_size determines the number of bytes available for dynamic 1495fd1e8a1fSTejun Heo * allocation in the first chunk. The area between @ai->static_size + 1496fd1e8a1fSTejun Heo * @ai->reserved_size + @ai->dyn_size and @ai->unit_size is unused. 14976074d5b0STejun Heo * 1498fd1e8a1fSTejun Heo * @ai->unit_size specifies unit size and must be aligned to PAGE_SIZE 1499fd1e8a1fSTejun Heo * and equal to or larger than @ai->static_size + @ai->reserved_size + 1500fd1e8a1fSTejun Heo * @ai->dyn_size. 15018d408b4bSTejun Heo * 1502fd1e8a1fSTejun Heo * @ai->atom_size is the allocation atom size and used as alignment 1503fd1e8a1fSTejun Heo * for vm areas. 15048d408b4bSTejun Heo * 1505fd1e8a1fSTejun Heo * @ai->alloc_size is the allocation size and always multiple of 1506fd1e8a1fSTejun Heo * @ai->atom_size. This is larger than @ai->atom_size if 1507fd1e8a1fSTejun Heo * @ai->unit_size is larger than @ai->atom_size. 1508fd1e8a1fSTejun Heo * 1509fd1e8a1fSTejun Heo * @ai->nr_groups and @ai->groups describe virtual memory layout of 1510fd1e8a1fSTejun Heo * percpu areas. Units which should be colocated are put into the 1511fd1e8a1fSTejun Heo * same group. Dynamic VM areas will be allocated according to these 1512fd1e8a1fSTejun Heo * groupings. If @ai->nr_groups is zero, a single group containing 1513fd1e8a1fSTejun Heo * all units is assumed. 15148d408b4bSTejun Heo * 151538a6be52STejun Heo * The caller should have mapped the first chunk at @base_addr and 151638a6be52STejun Heo * copied static data to each unit. 1517fbf59bc9STejun Heo * 1518edcb4639STejun Heo * If the first chunk ends up with both reserved and dynamic areas, it 1519edcb4639STejun Heo * is served by two chunks - one to serve the core static and reserved 1520edcb4639STejun Heo * areas and the other for the dynamic area. They share the same vm 1521edcb4639STejun Heo * and page map but uses different area allocation map to stay away 1522edcb4639STejun Heo * from each other. The latter chunk is circulated in the chunk slots 1523edcb4639STejun Heo * and available for dynamic allocation like any other chunks. 1524edcb4639STejun Heo * 1525fbf59bc9STejun Heo * RETURNS: 1526fb435d52STejun Heo * 0 on success, -errno on failure. 1527fbf59bc9STejun Heo */ 1528fb435d52STejun Heo int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, 1529fd1e8a1fSTejun Heo void *base_addr) 1530fbf59bc9STejun Heo { 1531635b75fcSTejun Heo static char cpus_buf[4096] __initdata; 1532099a19d9STejun Heo static int smap[PERCPU_DYNAMIC_EARLY_SLOTS] __initdata; 1533099a19d9STejun Heo static int dmap[PERCPU_DYNAMIC_EARLY_SLOTS] __initdata; 1534fd1e8a1fSTejun Heo size_t dyn_size = ai->dyn_size; 1535fd1e8a1fSTejun Heo size_t size_sum = ai->static_size + ai->reserved_size + dyn_size; 1536edcb4639STejun Heo struct pcpu_chunk *schunk, *dchunk = NULL; 15376563297cSTejun Heo unsigned long *group_offsets; 15386563297cSTejun Heo size_t *group_sizes; 1539fb435d52STejun Heo unsigned long *unit_off; 1540fbf59bc9STejun Heo unsigned int cpu; 1541fd1e8a1fSTejun Heo int *unit_map; 1542fd1e8a1fSTejun Heo int group, unit, i; 1543fbf59bc9STejun Heo 1544635b75fcSTejun Heo cpumask_scnprintf(cpus_buf, sizeof(cpus_buf), cpu_possible_mask); 1545635b75fcSTejun Heo 1546635b75fcSTejun Heo #define PCPU_SETUP_BUG_ON(cond) do { \ 1547635b75fcSTejun Heo if (unlikely(cond)) { \ 1548635b75fcSTejun Heo pr_emerg("PERCPU: failed to initialize, %s", #cond); \ 1549635b75fcSTejun Heo pr_emerg("PERCPU: cpu_possible_mask=%s\n", cpus_buf); \ 1550635b75fcSTejun Heo pcpu_dump_alloc_info(KERN_EMERG, ai); \ 1551635b75fcSTejun Heo BUG(); \ 1552635b75fcSTejun Heo } \ 1553635b75fcSTejun Heo } while (0) 1554635b75fcSTejun Heo 15552f39e637STejun Heo /* sanity checks */ 1556635b75fcSTejun Heo PCPU_SETUP_BUG_ON(ai->nr_groups <= 0); 1557bbddff05STejun Heo #ifdef CONFIG_SMP 1558635b75fcSTejun Heo PCPU_SETUP_BUG_ON(!ai->static_size); 15590415b00dSTejun Heo PCPU_SETUP_BUG_ON((unsigned long)__per_cpu_start & ~PAGE_MASK); 1560bbddff05STejun Heo #endif 1561635b75fcSTejun Heo PCPU_SETUP_BUG_ON(!base_addr); 15620415b00dSTejun Heo PCPU_SETUP_BUG_ON((unsigned long)base_addr & ~PAGE_MASK); 1563635b75fcSTejun Heo PCPU_SETUP_BUG_ON(ai->unit_size < size_sum); 1564635b75fcSTejun Heo PCPU_SETUP_BUG_ON(ai->unit_size & ~PAGE_MASK); 1565635b75fcSTejun Heo PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE); 1566099a19d9STejun Heo PCPU_SETUP_BUG_ON(ai->dyn_size < PERCPU_DYNAMIC_EARLY_SIZE); 15679f645532STejun Heo PCPU_SETUP_BUG_ON(pcpu_verify_alloc_info(ai) < 0); 15688d408b4bSTejun Heo 15696563297cSTejun Heo /* process group information and build config tables accordingly */ 1570999c17e3SSantosh Shilimkar group_offsets = memblock_virt_alloc(ai->nr_groups * 1571999c17e3SSantosh Shilimkar sizeof(group_offsets[0]), 0); 1572999c17e3SSantosh Shilimkar group_sizes = memblock_virt_alloc(ai->nr_groups * 1573999c17e3SSantosh Shilimkar sizeof(group_sizes[0]), 0); 1574999c17e3SSantosh Shilimkar unit_map = memblock_virt_alloc(nr_cpu_ids * sizeof(unit_map[0]), 0); 1575999c17e3SSantosh Shilimkar unit_off = memblock_virt_alloc(nr_cpu_ids * sizeof(unit_off[0]), 0); 15762f39e637STejun Heo 1577fd1e8a1fSTejun Heo for (cpu = 0; cpu < nr_cpu_ids; cpu++) 1578ffe0d5a5STejun Heo unit_map[cpu] = UINT_MAX; 1579a855b84cSTejun Heo 1580a855b84cSTejun Heo pcpu_low_unit_cpu = NR_CPUS; 1581a855b84cSTejun Heo pcpu_high_unit_cpu = NR_CPUS; 15822f39e637STejun Heo 1583fd1e8a1fSTejun Heo for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) { 1584fd1e8a1fSTejun Heo const struct pcpu_group_info *gi = &ai->groups[group]; 15852f39e637STejun Heo 15866563297cSTejun Heo group_offsets[group] = gi->base_offset; 15876563297cSTejun Heo group_sizes[group] = gi->nr_units * ai->unit_size; 15886563297cSTejun Heo 1589fd1e8a1fSTejun Heo for (i = 0; i < gi->nr_units; i++) { 1590fd1e8a1fSTejun Heo cpu = gi->cpu_map[i]; 1591fd1e8a1fSTejun Heo if (cpu == NR_CPUS) 1592fd1e8a1fSTejun Heo continue; 1593fd1e8a1fSTejun Heo 1594*9f295664SDan Carpenter PCPU_SETUP_BUG_ON(cpu >= nr_cpu_ids); 1595635b75fcSTejun Heo PCPU_SETUP_BUG_ON(!cpu_possible(cpu)); 1596635b75fcSTejun Heo PCPU_SETUP_BUG_ON(unit_map[cpu] != UINT_MAX); 1597fd1e8a1fSTejun Heo 1598fd1e8a1fSTejun Heo unit_map[cpu] = unit + i; 1599fb435d52STejun Heo unit_off[cpu] = gi->base_offset + i * ai->unit_size; 1600fb435d52STejun Heo 1601a855b84cSTejun Heo /* determine low/high unit_cpu */ 1602a855b84cSTejun Heo if (pcpu_low_unit_cpu == NR_CPUS || 1603a855b84cSTejun Heo unit_off[cpu] < unit_off[pcpu_low_unit_cpu]) 1604a855b84cSTejun Heo pcpu_low_unit_cpu = cpu; 1605a855b84cSTejun Heo if (pcpu_high_unit_cpu == NR_CPUS || 1606a855b84cSTejun Heo unit_off[cpu] > unit_off[pcpu_high_unit_cpu]) 1607a855b84cSTejun Heo pcpu_high_unit_cpu = cpu; 16080fc0531eSLinus Torvalds } 16090fc0531eSLinus Torvalds } 1610fd1e8a1fSTejun Heo pcpu_nr_units = unit; 16112f39e637STejun Heo 16122f39e637STejun Heo for_each_possible_cpu(cpu) 1613635b75fcSTejun Heo PCPU_SETUP_BUG_ON(unit_map[cpu] == UINT_MAX); 1614635b75fcSTejun Heo 1615635b75fcSTejun Heo /* we're done parsing the input, undefine BUG macro and dump config */ 1616635b75fcSTejun Heo #undef PCPU_SETUP_BUG_ON 1617bcbea798STejun Heo pcpu_dump_alloc_info(KERN_DEBUG, ai); 16182f39e637STejun Heo 16196563297cSTejun Heo pcpu_nr_groups = ai->nr_groups; 16206563297cSTejun Heo pcpu_group_offsets = group_offsets; 16216563297cSTejun Heo pcpu_group_sizes = group_sizes; 1622fd1e8a1fSTejun Heo pcpu_unit_map = unit_map; 1623fb435d52STejun Heo pcpu_unit_offsets = unit_off; 16242f39e637STejun Heo 16252f39e637STejun Heo /* determine basic parameters */ 1626fd1e8a1fSTejun Heo pcpu_unit_pages = ai->unit_size >> PAGE_SHIFT; 1627d9b55eebSTejun Heo pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT; 16286563297cSTejun Heo pcpu_atom_size = ai->atom_size; 1629ce3141a2STejun Heo pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) + 1630ce3141a2STejun Heo BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long); 1631cafe8816STejun Heo 1632d9b55eebSTejun Heo /* 1633d9b55eebSTejun Heo * Allocate chunk slots. The additional last slot is for 1634d9b55eebSTejun Heo * empty chunks. 1635d9b55eebSTejun Heo */ 1636d9b55eebSTejun Heo pcpu_nr_slots = __pcpu_size_to_slot(pcpu_unit_size) + 2; 1637999c17e3SSantosh Shilimkar pcpu_slot = memblock_virt_alloc( 1638999c17e3SSantosh Shilimkar pcpu_nr_slots * sizeof(pcpu_slot[0]), 0); 1639fbf59bc9STejun Heo for (i = 0; i < pcpu_nr_slots; i++) 1640fbf59bc9STejun Heo INIT_LIST_HEAD(&pcpu_slot[i]); 1641fbf59bc9STejun Heo 1642edcb4639STejun Heo /* 1643edcb4639STejun Heo * Initialize static chunk. If reserved_size is zero, the 1644edcb4639STejun Heo * static chunk covers static area + dynamic allocation area 1645edcb4639STejun Heo * in the first chunk. If reserved_size is not zero, it 1646edcb4639STejun Heo * covers static area + reserved area (mostly used for module 1647edcb4639STejun Heo * static percpu allocation). 1648edcb4639STejun Heo */ 1649999c17e3SSantosh Shilimkar schunk = memblock_virt_alloc(pcpu_chunk_struct_size, 0); 16502441d15cSTejun Heo INIT_LIST_HEAD(&schunk->list); 16519c824b6aSTejun Heo INIT_WORK(&schunk->map_extend_work, pcpu_map_extend_workfn); 1652bba174f5STejun Heo schunk->base_addr = base_addr; 165361ace7faSTejun Heo schunk->map = smap; 165461ace7faSTejun Heo schunk->map_alloc = ARRAY_SIZE(smap); 165538a6be52STejun Heo schunk->immutable = true; 1656ce3141a2STejun Heo bitmap_fill(schunk->populated, pcpu_unit_pages); 1657b539b87fSTejun Heo schunk->nr_populated = pcpu_unit_pages; 1658edcb4639STejun Heo 1659fd1e8a1fSTejun Heo if (ai->reserved_size) { 1660fd1e8a1fSTejun Heo schunk->free_size = ai->reserved_size; 1661ae9e6bc9STejun Heo pcpu_reserved_chunk = schunk; 1662fd1e8a1fSTejun Heo pcpu_reserved_chunk_limit = ai->static_size + ai->reserved_size; 1663edcb4639STejun Heo } else { 16642441d15cSTejun Heo schunk->free_size = dyn_size; 1665edcb4639STejun Heo dyn_size = 0; /* dynamic area covered */ 1666edcb4639STejun Heo } 16672441d15cSTejun Heo schunk->contig_hint = schunk->free_size; 1668fbf59bc9STejun Heo 1669723ad1d9SAl Viro schunk->map[0] = 1; 1670723ad1d9SAl Viro schunk->map[1] = ai->static_size; 1671723ad1d9SAl Viro schunk->map_used = 1; 167261ace7faSTejun Heo if (schunk->free_size) 1673723ad1d9SAl Viro schunk->map[++schunk->map_used] = 1 | (ai->static_size + schunk->free_size); 1674723ad1d9SAl Viro else 1675723ad1d9SAl Viro schunk->map[1] |= 1; 167661ace7faSTejun Heo 1677edcb4639STejun Heo /* init dynamic chunk if necessary */ 1678edcb4639STejun Heo if (dyn_size) { 1679999c17e3SSantosh Shilimkar dchunk = memblock_virt_alloc(pcpu_chunk_struct_size, 0); 1680edcb4639STejun Heo INIT_LIST_HEAD(&dchunk->list); 16819c824b6aSTejun Heo INIT_WORK(&dchunk->map_extend_work, pcpu_map_extend_workfn); 1682bba174f5STejun Heo dchunk->base_addr = base_addr; 1683edcb4639STejun Heo dchunk->map = dmap; 1684edcb4639STejun Heo dchunk->map_alloc = ARRAY_SIZE(dmap); 168538a6be52STejun Heo dchunk->immutable = true; 1686ce3141a2STejun Heo bitmap_fill(dchunk->populated, pcpu_unit_pages); 1687b539b87fSTejun Heo dchunk->nr_populated = pcpu_unit_pages; 1688edcb4639STejun Heo 1689edcb4639STejun Heo dchunk->contig_hint = dchunk->free_size = dyn_size; 1690723ad1d9SAl Viro dchunk->map[0] = 1; 1691723ad1d9SAl Viro dchunk->map[1] = pcpu_reserved_chunk_limit; 1692723ad1d9SAl Viro dchunk->map[2] = (pcpu_reserved_chunk_limit + dchunk->free_size) | 1; 1693723ad1d9SAl Viro dchunk->map_used = 2; 1694edcb4639STejun Heo } 1695edcb4639STejun Heo 16962441d15cSTejun Heo /* link the first chunk in */ 1697ae9e6bc9STejun Heo pcpu_first_chunk = dchunk ?: schunk; 1698b539b87fSTejun Heo pcpu_nr_empty_pop_pages += 1699b539b87fSTejun Heo pcpu_count_occupied_pages(pcpu_first_chunk, 1); 1700ae9e6bc9STejun Heo pcpu_chunk_relocate(pcpu_first_chunk, -1); 1701fbf59bc9STejun Heo 1702fbf59bc9STejun Heo /* we're done */ 1703bba174f5STejun Heo pcpu_base_addr = base_addr; 1704fb435d52STejun Heo return 0; 1705fbf59bc9STejun Heo } 170666c3a757STejun Heo 1707bbddff05STejun Heo #ifdef CONFIG_SMP 1708bbddff05STejun Heo 170917f3609cSAndi Kleen const char * const pcpu_fc_names[PCPU_FC_NR] __initconst = { 1710f58dc01bSTejun Heo [PCPU_FC_AUTO] = "auto", 1711f58dc01bSTejun Heo [PCPU_FC_EMBED] = "embed", 1712f58dc01bSTejun Heo [PCPU_FC_PAGE] = "page", 1713f58dc01bSTejun Heo }; 171466c3a757STejun Heo 1715f58dc01bSTejun Heo enum pcpu_fc pcpu_chosen_fc __initdata = PCPU_FC_AUTO; 1716f58dc01bSTejun Heo 1717f58dc01bSTejun Heo static int __init percpu_alloc_setup(char *str) 171866c3a757STejun Heo { 17195479c78aSCyrill Gorcunov if (!str) 17205479c78aSCyrill Gorcunov return -EINVAL; 17215479c78aSCyrill Gorcunov 1722f58dc01bSTejun Heo if (0) 1723f58dc01bSTejun Heo /* nada */; 1724f58dc01bSTejun Heo #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK 1725f58dc01bSTejun Heo else if (!strcmp(str, "embed")) 1726f58dc01bSTejun Heo pcpu_chosen_fc = PCPU_FC_EMBED; 1727f58dc01bSTejun Heo #endif 1728f58dc01bSTejun Heo #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK 1729f58dc01bSTejun Heo else if (!strcmp(str, "page")) 1730f58dc01bSTejun Heo pcpu_chosen_fc = PCPU_FC_PAGE; 1731f58dc01bSTejun Heo #endif 1732f58dc01bSTejun Heo else 1733f58dc01bSTejun Heo pr_warning("PERCPU: unknown allocator %s specified\n", str); 173466c3a757STejun Heo 1735f58dc01bSTejun Heo return 0; 173666c3a757STejun Heo } 1737f58dc01bSTejun Heo early_param("percpu_alloc", percpu_alloc_setup); 173866c3a757STejun Heo 17393c9a024fSTejun Heo /* 17403c9a024fSTejun Heo * pcpu_embed_first_chunk() is used by the generic percpu setup. 17413c9a024fSTejun Heo * Build it if needed by the arch config or the generic setup is going 17423c9a024fSTejun Heo * to be used. 17433c9a024fSTejun Heo */ 174408fc4580STejun Heo #if defined(CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK) || \ 174508fc4580STejun Heo !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) 17463c9a024fSTejun Heo #define BUILD_EMBED_FIRST_CHUNK 17473c9a024fSTejun Heo #endif 17483c9a024fSTejun Heo 17493c9a024fSTejun Heo /* build pcpu_page_first_chunk() iff needed by the arch config */ 17503c9a024fSTejun Heo #if defined(CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK) 17513c9a024fSTejun Heo #define BUILD_PAGE_FIRST_CHUNK 17523c9a024fSTejun Heo #endif 17533c9a024fSTejun Heo 17543c9a024fSTejun Heo /* pcpu_build_alloc_info() is used by both embed and page first chunk */ 17553c9a024fSTejun Heo #if defined(BUILD_EMBED_FIRST_CHUNK) || defined(BUILD_PAGE_FIRST_CHUNK) 17563c9a024fSTejun Heo /** 1757fbf59bc9STejun Heo * pcpu_build_alloc_info - build alloc_info considering distances between CPUs 1758fbf59bc9STejun Heo * @reserved_size: the size of reserved percpu area in bytes 1759fbf59bc9STejun Heo * @dyn_size: minimum free size for dynamic allocation in bytes 1760fbf59bc9STejun Heo * @atom_size: allocation atom size 1761fbf59bc9STejun Heo * @cpu_distance_fn: callback to determine distance between cpus, optional 1762fbf59bc9STejun Heo * 1763fbf59bc9STejun Heo * This function determines grouping of units, their mappings to cpus 1764fbf59bc9STejun Heo * and other parameters considering needed percpu size, allocation 1765fbf59bc9STejun Heo * atom size and distances between CPUs. 1766fbf59bc9STejun Heo * 1767fbf59bc9STejun Heo * Groups are always mutliples of atom size and CPUs which are of 1768fbf59bc9STejun Heo * LOCAL_DISTANCE both ways are grouped together and share space for 1769fbf59bc9STejun Heo * units in the same group. The returned configuration is guaranteed 1770fbf59bc9STejun Heo * to have CPUs on different nodes on different groups and >=75% usage 1771fbf59bc9STejun Heo * of allocated virtual address space. 1772fbf59bc9STejun Heo * 1773fbf59bc9STejun Heo * RETURNS: 1774fbf59bc9STejun Heo * On success, pointer to the new allocation_info is returned. On 1775fbf59bc9STejun Heo * failure, ERR_PTR value is returned. 1776fbf59bc9STejun Heo */ 1777fbf59bc9STejun Heo static struct pcpu_alloc_info * __init pcpu_build_alloc_info( 1778fbf59bc9STejun Heo size_t reserved_size, size_t dyn_size, 1779fbf59bc9STejun Heo size_t atom_size, 1780fbf59bc9STejun Heo pcpu_fc_cpu_distance_fn_t cpu_distance_fn) 1781fbf59bc9STejun Heo { 1782fbf59bc9STejun Heo static int group_map[NR_CPUS] __initdata; 1783fbf59bc9STejun Heo static int group_cnt[NR_CPUS] __initdata; 1784fbf59bc9STejun Heo const size_t static_size = __per_cpu_end - __per_cpu_start; 1785fbf59bc9STejun Heo int nr_groups = 1, nr_units = 0; 1786fbf59bc9STejun Heo size_t size_sum, min_unit_size, alloc_size; 1787fbf59bc9STejun Heo int upa, max_upa, uninitialized_var(best_upa); /* units_per_alloc */ 1788fbf59bc9STejun Heo int last_allocs, group, unit; 1789fbf59bc9STejun Heo unsigned int cpu, tcpu; 1790fbf59bc9STejun Heo struct pcpu_alloc_info *ai; 1791fbf59bc9STejun Heo unsigned int *cpu_map; 1792fbf59bc9STejun Heo 1793fbf59bc9STejun Heo /* this function may be called multiple times */ 1794fbf59bc9STejun Heo memset(group_map, 0, sizeof(group_map)); 1795fbf59bc9STejun Heo memset(group_cnt, 0, sizeof(group_cnt)); 1796fbf59bc9STejun Heo 1797fbf59bc9STejun Heo /* calculate size_sum and ensure dyn_size is enough for early alloc */ 1798fbf59bc9STejun Heo size_sum = PFN_ALIGN(static_size + reserved_size + 1799fbf59bc9STejun Heo max_t(size_t, dyn_size, PERCPU_DYNAMIC_EARLY_SIZE)); 1800fbf59bc9STejun Heo dyn_size = size_sum - static_size - reserved_size; 1801fbf59bc9STejun Heo 1802fbf59bc9STejun Heo /* 1803fbf59bc9STejun Heo * Determine min_unit_size, alloc_size and max_upa such that 1804fbf59bc9STejun Heo * alloc_size is multiple of atom_size and is the smallest 180525985edcSLucas De Marchi * which can accommodate 4k aligned segments which are equal to 1806fbf59bc9STejun Heo * or larger than min_unit_size. 1807fbf59bc9STejun Heo */ 1808fbf59bc9STejun Heo min_unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE); 1809fbf59bc9STejun Heo 1810fbf59bc9STejun Heo alloc_size = roundup(min_unit_size, atom_size); 1811fbf59bc9STejun Heo upa = alloc_size / min_unit_size; 1812fbf59bc9STejun Heo while (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK)) 1813fbf59bc9STejun Heo upa--; 1814fbf59bc9STejun Heo max_upa = upa; 1815fbf59bc9STejun Heo 1816fbf59bc9STejun Heo /* group cpus according to their proximity */ 1817fbf59bc9STejun Heo for_each_possible_cpu(cpu) { 1818fbf59bc9STejun Heo group = 0; 1819fbf59bc9STejun Heo next_group: 1820fbf59bc9STejun Heo for_each_possible_cpu(tcpu) { 1821fbf59bc9STejun Heo if (cpu == tcpu) 1822fbf59bc9STejun Heo break; 1823fbf59bc9STejun Heo if (group_map[tcpu] == group && cpu_distance_fn && 1824fbf59bc9STejun Heo (cpu_distance_fn(cpu, tcpu) > LOCAL_DISTANCE || 1825fbf59bc9STejun Heo cpu_distance_fn(tcpu, cpu) > LOCAL_DISTANCE)) { 1826fbf59bc9STejun Heo group++; 1827fbf59bc9STejun Heo nr_groups = max(nr_groups, group + 1); 1828fbf59bc9STejun Heo goto next_group; 1829fbf59bc9STejun Heo } 1830fbf59bc9STejun Heo } 1831fbf59bc9STejun Heo group_map[cpu] = group; 1832fbf59bc9STejun Heo group_cnt[group]++; 1833fbf59bc9STejun Heo } 1834fbf59bc9STejun Heo 1835fbf59bc9STejun Heo /* 1836fbf59bc9STejun Heo * Expand unit size until address space usage goes over 75% 1837fbf59bc9STejun Heo * and then as much as possible without using more address 1838fbf59bc9STejun Heo * space. 1839fbf59bc9STejun Heo */ 1840fbf59bc9STejun Heo last_allocs = INT_MAX; 1841fbf59bc9STejun Heo for (upa = max_upa; upa; upa--) { 1842fbf59bc9STejun Heo int allocs = 0, wasted = 0; 1843fbf59bc9STejun Heo 1844fbf59bc9STejun Heo if (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK)) 1845fbf59bc9STejun Heo continue; 1846fbf59bc9STejun Heo 1847fbf59bc9STejun Heo for (group = 0; group < nr_groups; group++) { 1848fbf59bc9STejun Heo int this_allocs = DIV_ROUND_UP(group_cnt[group], upa); 1849fbf59bc9STejun Heo allocs += this_allocs; 1850fbf59bc9STejun Heo wasted += this_allocs * upa - group_cnt[group]; 1851fbf59bc9STejun Heo } 1852fbf59bc9STejun Heo 1853fbf59bc9STejun Heo /* 1854fbf59bc9STejun Heo * Don't accept if wastage is over 1/3. The 1855fbf59bc9STejun Heo * greater-than comparison ensures upa==1 always 1856fbf59bc9STejun Heo * passes the following check. 1857fbf59bc9STejun Heo */ 1858fbf59bc9STejun Heo if (wasted > num_possible_cpus() / 3) 1859fbf59bc9STejun Heo continue; 1860fbf59bc9STejun Heo 1861fbf59bc9STejun Heo /* and then don't consume more memory */ 1862fbf59bc9STejun Heo if (allocs > last_allocs) 1863fbf59bc9STejun Heo break; 1864fbf59bc9STejun Heo last_allocs = allocs; 1865fbf59bc9STejun Heo best_upa = upa; 1866fbf59bc9STejun Heo } 1867fbf59bc9STejun Heo upa = best_upa; 1868fbf59bc9STejun Heo 1869fbf59bc9STejun Heo /* allocate and fill alloc_info */ 1870fbf59bc9STejun Heo for (group = 0; group < nr_groups; group++) 1871fbf59bc9STejun Heo nr_units += roundup(group_cnt[group], upa); 1872fbf59bc9STejun Heo 1873fbf59bc9STejun Heo ai = pcpu_alloc_alloc_info(nr_groups, nr_units); 1874fbf59bc9STejun Heo if (!ai) 1875fbf59bc9STejun Heo return ERR_PTR(-ENOMEM); 1876fbf59bc9STejun Heo cpu_map = ai->groups[0].cpu_map; 1877fbf59bc9STejun Heo 1878fbf59bc9STejun Heo for (group = 0; group < nr_groups; group++) { 1879fbf59bc9STejun Heo ai->groups[group].cpu_map = cpu_map; 1880fbf59bc9STejun Heo cpu_map += roundup(group_cnt[group], upa); 1881fbf59bc9STejun Heo } 1882fbf59bc9STejun Heo 1883fbf59bc9STejun Heo ai->static_size = static_size; 1884fbf59bc9STejun Heo ai->reserved_size = reserved_size; 1885fbf59bc9STejun Heo ai->dyn_size = dyn_size; 1886fbf59bc9STejun Heo ai->unit_size = alloc_size / upa; 1887fbf59bc9STejun Heo ai->atom_size = atom_size; 1888fbf59bc9STejun Heo ai->alloc_size = alloc_size; 1889fbf59bc9STejun Heo 1890fbf59bc9STejun Heo for (group = 0, unit = 0; group_cnt[group]; group++) { 1891fbf59bc9STejun Heo struct pcpu_group_info *gi = &ai->groups[group]; 1892fbf59bc9STejun Heo 1893fbf59bc9STejun Heo /* 1894fbf59bc9STejun Heo * Initialize base_offset as if all groups are located 1895fbf59bc9STejun Heo * back-to-back. The caller should update this to 1896fbf59bc9STejun Heo * reflect actual allocation. 1897fbf59bc9STejun Heo */ 1898fbf59bc9STejun Heo gi->base_offset = unit * ai->unit_size; 1899fbf59bc9STejun Heo 1900fbf59bc9STejun Heo for_each_possible_cpu(cpu) 1901fbf59bc9STejun Heo if (group_map[cpu] == group) 1902fbf59bc9STejun Heo gi->cpu_map[gi->nr_units++] = cpu; 1903fbf59bc9STejun Heo gi->nr_units = roundup(gi->nr_units, upa); 1904fbf59bc9STejun Heo unit += gi->nr_units; 1905fbf59bc9STejun Heo } 1906fbf59bc9STejun Heo BUG_ON(unit != nr_units); 1907fbf59bc9STejun Heo 1908fbf59bc9STejun Heo return ai; 1909fbf59bc9STejun Heo } 19103c9a024fSTejun Heo #endif /* BUILD_EMBED_FIRST_CHUNK || BUILD_PAGE_FIRST_CHUNK */ 1911fbf59bc9STejun Heo 19123c9a024fSTejun Heo #if defined(BUILD_EMBED_FIRST_CHUNK) 191366c3a757STejun Heo /** 191466c3a757STejun Heo * pcpu_embed_first_chunk - embed the first percpu chunk into bootmem 191566c3a757STejun Heo * @reserved_size: the size of reserved percpu area in bytes 19164ba6ce25STejun Heo * @dyn_size: minimum free size for dynamic allocation in bytes 1917c8826dd5STejun Heo * @atom_size: allocation atom size 1918c8826dd5STejun Heo * @cpu_distance_fn: callback to determine distance between cpus, optional 1919c8826dd5STejun Heo * @alloc_fn: function to allocate percpu page 192025985edcSLucas De Marchi * @free_fn: function to free percpu page 192166c3a757STejun Heo * 192266c3a757STejun Heo * This is a helper to ease setting up embedded first percpu chunk and 192366c3a757STejun Heo * can be called where pcpu_setup_first_chunk() is expected. 192466c3a757STejun Heo * 192566c3a757STejun Heo * If this function is used to setup the first chunk, it is allocated 1926c8826dd5STejun Heo * by calling @alloc_fn and used as-is without being mapped into 1927c8826dd5STejun Heo * vmalloc area. Allocations are always whole multiples of @atom_size 1928c8826dd5STejun Heo * aligned to @atom_size. 1929c8826dd5STejun Heo * 1930c8826dd5STejun Heo * This enables the first chunk to piggy back on the linear physical 1931c8826dd5STejun Heo * mapping which often uses larger page size. Please note that this 1932c8826dd5STejun Heo * can result in very sparse cpu->unit mapping on NUMA machines thus 1933c8826dd5STejun Heo * requiring large vmalloc address space. Don't use this allocator if 1934c8826dd5STejun Heo * vmalloc space is not orders of magnitude larger than distances 1935c8826dd5STejun Heo * between node memory addresses (ie. 32bit NUMA machines). 193666c3a757STejun Heo * 19374ba6ce25STejun Heo * @dyn_size specifies the minimum dynamic area size. 193866c3a757STejun Heo * 193966c3a757STejun Heo * If the needed size is smaller than the minimum or specified unit 1940c8826dd5STejun Heo * size, the leftover is returned using @free_fn. 194166c3a757STejun Heo * 194266c3a757STejun Heo * RETURNS: 1943fb435d52STejun Heo * 0 on success, -errno on failure. 194466c3a757STejun Heo */ 19454ba6ce25STejun Heo int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, 1946c8826dd5STejun Heo size_t atom_size, 1947c8826dd5STejun Heo pcpu_fc_cpu_distance_fn_t cpu_distance_fn, 1948c8826dd5STejun Heo pcpu_fc_alloc_fn_t alloc_fn, 1949c8826dd5STejun Heo pcpu_fc_free_fn_t free_fn) 195066c3a757STejun Heo { 1951c8826dd5STejun Heo void *base = (void *)ULONG_MAX; 1952c8826dd5STejun Heo void **areas = NULL; 1953fd1e8a1fSTejun Heo struct pcpu_alloc_info *ai; 19546ea529a2STejun Heo size_t size_sum, areas_size, max_distance; 1955c8826dd5STejun Heo int group, i, rc; 195666c3a757STejun Heo 1957c8826dd5STejun Heo ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size, 1958c8826dd5STejun Heo cpu_distance_fn); 1959fd1e8a1fSTejun Heo if (IS_ERR(ai)) 1960fd1e8a1fSTejun Heo return PTR_ERR(ai); 196166c3a757STejun Heo 1962fd1e8a1fSTejun Heo size_sum = ai->static_size + ai->reserved_size + ai->dyn_size; 1963c8826dd5STejun Heo areas_size = PFN_ALIGN(ai->nr_groups * sizeof(void *)); 196466c3a757STejun Heo 1965999c17e3SSantosh Shilimkar areas = memblock_virt_alloc_nopanic(areas_size, 0); 1966c8826dd5STejun Heo if (!areas) { 1967fb435d52STejun Heo rc = -ENOMEM; 1968c8826dd5STejun Heo goto out_free; 1969fa8a7094STejun Heo } 197066c3a757STejun Heo 1971c8826dd5STejun Heo /* allocate, copy and determine base address */ 1972c8826dd5STejun Heo for (group = 0; group < ai->nr_groups; group++) { 1973c8826dd5STejun Heo struct pcpu_group_info *gi = &ai->groups[group]; 1974c8826dd5STejun Heo unsigned int cpu = NR_CPUS; 1975c8826dd5STejun Heo void *ptr; 197666c3a757STejun Heo 1977c8826dd5STejun Heo for (i = 0; i < gi->nr_units && cpu == NR_CPUS; i++) 1978c8826dd5STejun Heo cpu = gi->cpu_map[i]; 1979c8826dd5STejun Heo BUG_ON(cpu == NR_CPUS); 1980c8826dd5STejun Heo 1981c8826dd5STejun Heo /* allocate space for the whole group */ 1982c8826dd5STejun Heo ptr = alloc_fn(cpu, gi->nr_units * ai->unit_size, atom_size); 1983c8826dd5STejun Heo if (!ptr) { 1984c8826dd5STejun Heo rc = -ENOMEM; 1985c8826dd5STejun Heo goto out_free_areas; 1986c8826dd5STejun Heo } 1987f528f0b8SCatalin Marinas /* kmemleak tracks the percpu allocations separately */ 1988f528f0b8SCatalin Marinas kmemleak_free(ptr); 1989c8826dd5STejun Heo areas[group] = ptr; 1990c8826dd5STejun Heo 1991c8826dd5STejun Heo base = min(ptr, base); 199242b64281STejun Heo } 199342b64281STejun Heo 199442b64281STejun Heo /* 199542b64281STejun Heo * Copy data and free unused parts. This should happen after all 199642b64281STejun Heo * allocations are complete; otherwise, we may end up with 199742b64281STejun Heo * overlapping groups. 199842b64281STejun Heo */ 199942b64281STejun Heo for (group = 0; group < ai->nr_groups; group++) { 200042b64281STejun Heo struct pcpu_group_info *gi = &ai->groups[group]; 200142b64281STejun Heo void *ptr = areas[group]; 2002c8826dd5STejun Heo 2003c8826dd5STejun Heo for (i = 0; i < gi->nr_units; i++, ptr += ai->unit_size) { 2004c8826dd5STejun Heo if (gi->cpu_map[i] == NR_CPUS) { 2005c8826dd5STejun Heo /* unused unit, free whole */ 2006c8826dd5STejun Heo free_fn(ptr, ai->unit_size); 2007c8826dd5STejun Heo continue; 2008c8826dd5STejun Heo } 2009c8826dd5STejun Heo /* copy and return the unused part */ 2010fd1e8a1fSTejun Heo memcpy(ptr, __per_cpu_load, ai->static_size); 2011c8826dd5STejun Heo free_fn(ptr + size_sum, ai->unit_size - size_sum); 2012c8826dd5STejun Heo } 201366c3a757STejun Heo } 201466c3a757STejun Heo 2015c8826dd5STejun Heo /* base address is now known, determine group base offsets */ 20166ea529a2STejun Heo max_distance = 0; 20176ea529a2STejun Heo for (group = 0; group < ai->nr_groups; group++) { 2018c8826dd5STejun Heo ai->groups[group].base_offset = areas[group] - base; 20191a0c3298STejun Heo max_distance = max_t(size_t, max_distance, 20201a0c3298STejun Heo ai->groups[group].base_offset); 20216ea529a2STejun Heo } 20226ea529a2STejun Heo max_distance += ai->unit_size; 20236ea529a2STejun Heo 20246ea529a2STejun Heo /* warn if maximum distance is further than 75% of vmalloc space */ 20258a092171SLaura Abbott if (max_distance > VMALLOC_TOTAL * 3 / 4) { 20261a0c3298STejun Heo pr_warning("PERCPU: max_distance=0x%zx too large for vmalloc " 2027787e5b06SMike Frysinger "space 0x%lx\n", max_distance, 20288a092171SLaura Abbott VMALLOC_TOTAL); 20296ea529a2STejun Heo #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK 20306ea529a2STejun Heo /* and fail if we have fallback */ 20316ea529a2STejun Heo rc = -EINVAL; 20326ea529a2STejun Heo goto out_free; 20336ea529a2STejun Heo #endif 20346ea529a2STejun Heo } 2035c8826dd5STejun Heo 2036004018e2STejun Heo pr_info("PERCPU: Embedded %zu pages/cpu @%p s%zu r%zu d%zu u%zu\n", 2037fd1e8a1fSTejun Heo PFN_DOWN(size_sum), base, ai->static_size, ai->reserved_size, 2038fd1e8a1fSTejun Heo ai->dyn_size, ai->unit_size); 203966c3a757STejun Heo 2040fb435d52STejun Heo rc = pcpu_setup_first_chunk(ai, base); 2041c8826dd5STejun Heo goto out_free; 2042c8826dd5STejun Heo 2043c8826dd5STejun Heo out_free_areas: 2044c8826dd5STejun Heo for (group = 0; group < ai->nr_groups; group++) 2045f851c8d8SMichael Holzheu if (areas[group]) 2046c8826dd5STejun Heo free_fn(areas[group], 2047c8826dd5STejun Heo ai->groups[group].nr_units * ai->unit_size); 2048c8826dd5STejun Heo out_free: 2049fd1e8a1fSTejun Heo pcpu_free_alloc_info(ai); 2050c8826dd5STejun Heo if (areas) 2051999c17e3SSantosh Shilimkar memblock_free_early(__pa(areas), areas_size); 2052fb435d52STejun Heo return rc; 2053d4b95f80STejun Heo } 20543c9a024fSTejun Heo #endif /* BUILD_EMBED_FIRST_CHUNK */ 2055d4b95f80STejun Heo 20563c9a024fSTejun Heo #ifdef BUILD_PAGE_FIRST_CHUNK 2057d4b95f80STejun Heo /** 205800ae4064STejun Heo * pcpu_page_first_chunk - map the first chunk using PAGE_SIZE pages 2059d4b95f80STejun Heo * @reserved_size: the size of reserved percpu area in bytes 2060d4b95f80STejun Heo * @alloc_fn: function to allocate percpu page, always called with PAGE_SIZE 206125985edcSLucas De Marchi * @free_fn: function to free percpu page, always called with PAGE_SIZE 2062d4b95f80STejun Heo * @populate_pte_fn: function to populate pte 2063d4b95f80STejun Heo * 206400ae4064STejun Heo * This is a helper to ease setting up page-remapped first percpu 206500ae4064STejun Heo * chunk and can be called where pcpu_setup_first_chunk() is expected. 2066d4b95f80STejun Heo * 2067d4b95f80STejun Heo * This is the basic allocator. Static percpu area is allocated 2068d4b95f80STejun Heo * page-by-page into vmalloc area. 2069d4b95f80STejun Heo * 2070d4b95f80STejun Heo * RETURNS: 2071fb435d52STejun Heo * 0 on success, -errno on failure. 2072d4b95f80STejun Heo */ 2073fb435d52STejun Heo int __init pcpu_page_first_chunk(size_t reserved_size, 2074d4b95f80STejun Heo pcpu_fc_alloc_fn_t alloc_fn, 2075d4b95f80STejun Heo pcpu_fc_free_fn_t free_fn, 2076d4b95f80STejun Heo pcpu_fc_populate_pte_fn_t populate_pte_fn) 2077d4b95f80STejun Heo { 20788f05a6a6STejun Heo static struct vm_struct vm; 2079fd1e8a1fSTejun Heo struct pcpu_alloc_info *ai; 208000ae4064STejun Heo char psize_str[16]; 2081ce3141a2STejun Heo int unit_pages; 2082d4b95f80STejun Heo size_t pages_size; 2083ce3141a2STejun Heo struct page **pages; 2084fb435d52STejun Heo int unit, i, j, rc; 2085d4b95f80STejun Heo 208600ae4064STejun Heo snprintf(psize_str, sizeof(psize_str), "%luK", PAGE_SIZE >> 10); 208700ae4064STejun Heo 20884ba6ce25STejun Heo ai = pcpu_build_alloc_info(reserved_size, 0, PAGE_SIZE, NULL); 2089fd1e8a1fSTejun Heo if (IS_ERR(ai)) 2090fd1e8a1fSTejun Heo return PTR_ERR(ai); 2091fd1e8a1fSTejun Heo BUG_ON(ai->nr_groups != 1); 2092fd1e8a1fSTejun Heo BUG_ON(ai->groups[0].nr_units != num_possible_cpus()); 2093fd1e8a1fSTejun Heo 2094fd1e8a1fSTejun Heo unit_pages = ai->unit_size >> PAGE_SHIFT; 2095d4b95f80STejun Heo 2096d4b95f80STejun Heo /* unaligned allocations can't be freed, round up to page size */ 2097fd1e8a1fSTejun Heo pages_size = PFN_ALIGN(unit_pages * num_possible_cpus() * 2098fd1e8a1fSTejun Heo sizeof(pages[0])); 2099999c17e3SSantosh Shilimkar pages = memblock_virt_alloc(pages_size, 0); 2100d4b95f80STejun Heo 21018f05a6a6STejun Heo /* allocate pages */ 2102d4b95f80STejun Heo j = 0; 2103fd1e8a1fSTejun Heo for (unit = 0; unit < num_possible_cpus(); unit++) 2104ce3141a2STejun Heo for (i = 0; i < unit_pages; i++) { 2105fd1e8a1fSTejun Heo unsigned int cpu = ai->groups[0].cpu_map[unit]; 2106d4b95f80STejun Heo void *ptr; 2107d4b95f80STejun Heo 21083cbc8565STejun Heo ptr = alloc_fn(cpu, PAGE_SIZE, PAGE_SIZE); 2109d4b95f80STejun Heo if (!ptr) { 211000ae4064STejun Heo pr_warning("PERCPU: failed to allocate %s page " 211100ae4064STejun Heo "for cpu%u\n", psize_str, cpu); 2112d4b95f80STejun Heo goto enomem; 2113d4b95f80STejun Heo } 2114f528f0b8SCatalin Marinas /* kmemleak tracks the percpu allocations separately */ 2115f528f0b8SCatalin Marinas kmemleak_free(ptr); 2116ce3141a2STejun Heo pages[j++] = virt_to_page(ptr); 2117d4b95f80STejun Heo } 2118d4b95f80STejun Heo 21198f05a6a6STejun Heo /* allocate vm area, map the pages and copy static data */ 21208f05a6a6STejun Heo vm.flags = VM_ALLOC; 2121fd1e8a1fSTejun Heo vm.size = num_possible_cpus() * ai->unit_size; 21228f05a6a6STejun Heo vm_area_register_early(&vm, PAGE_SIZE); 21238f05a6a6STejun Heo 2124fd1e8a1fSTejun Heo for (unit = 0; unit < num_possible_cpus(); unit++) { 21251d9d3257STejun Heo unsigned long unit_addr = 2126fd1e8a1fSTejun Heo (unsigned long)vm.addr + unit * ai->unit_size; 21278f05a6a6STejun Heo 2128ce3141a2STejun Heo for (i = 0; i < unit_pages; i++) 21298f05a6a6STejun Heo populate_pte_fn(unit_addr + (i << PAGE_SHIFT)); 21308f05a6a6STejun Heo 21318f05a6a6STejun Heo /* pte already populated, the following shouldn't fail */ 2132fb435d52STejun Heo rc = __pcpu_map_pages(unit_addr, &pages[unit * unit_pages], 2133ce3141a2STejun Heo unit_pages); 2134fb435d52STejun Heo if (rc < 0) 2135fb435d52STejun Heo panic("failed to map percpu area, err=%d\n", rc); 21368f05a6a6STejun Heo 21378f05a6a6STejun Heo /* 21388f05a6a6STejun Heo * FIXME: Archs with virtual cache should flush local 21398f05a6a6STejun Heo * cache for the linear mapping here - something 21408f05a6a6STejun Heo * equivalent to flush_cache_vmap() on the local cpu. 21418f05a6a6STejun Heo * flush_cache_vmap() can't be used as most supporting 21428f05a6a6STejun Heo * data structures are not set up yet. 21438f05a6a6STejun Heo */ 21448f05a6a6STejun Heo 21458f05a6a6STejun Heo /* copy static data */ 2146fd1e8a1fSTejun Heo memcpy((void *)unit_addr, __per_cpu_load, ai->static_size); 214766c3a757STejun Heo } 214866c3a757STejun Heo 214966c3a757STejun Heo /* we're ready, commit */ 21501d9d3257STejun Heo pr_info("PERCPU: %d %s pages/cpu @%p s%zu r%zu d%zu\n", 2151fd1e8a1fSTejun Heo unit_pages, psize_str, vm.addr, ai->static_size, 2152fd1e8a1fSTejun Heo ai->reserved_size, ai->dyn_size); 215366c3a757STejun Heo 2154fb435d52STejun Heo rc = pcpu_setup_first_chunk(ai, vm.addr); 2155d4b95f80STejun Heo goto out_free_ar; 2156d4b95f80STejun Heo 2157d4b95f80STejun Heo enomem: 2158d4b95f80STejun Heo while (--j >= 0) 2159ce3141a2STejun Heo free_fn(page_address(pages[j]), PAGE_SIZE); 2160fb435d52STejun Heo rc = -ENOMEM; 2161d4b95f80STejun Heo out_free_ar: 2162999c17e3SSantosh Shilimkar memblock_free_early(__pa(pages), pages_size); 2163fd1e8a1fSTejun Heo pcpu_free_alloc_info(ai); 2164fb435d52STejun Heo return rc; 216566c3a757STejun Heo } 21663c9a024fSTejun Heo #endif /* BUILD_PAGE_FIRST_CHUNK */ 2167d4b95f80STejun Heo 2168bbddff05STejun Heo #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA 21698c4bfc6eSTejun Heo /* 2170bbddff05STejun Heo * Generic SMP percpu area setup. 2171e74e3962STejun Heo * 2172e74e3962STejun Heo * The embedding helper is used because its behavior closely resembles 2173e74e3962STejun Heo * the original non-dynamic generic percpu area setup. This is 2174e74e3962STejun Heo * important because many archs have addressing restrictions and might 2175e74e3962STejun Heo * fail if the percpu area is located far away from the previous 2176e74e3962STejun Heo * location. As an added bonus, in non-NUMA cases, embedding is 2177e74e3962STejun Heo * generally a good idea TLB-wise because percpu area can piggy back 2178e74e3962STejun Heo * on the physical linear memory mapping which uses large page 2179e74e3962STejun Heo * mappings on applicable archs. 2180e74e3962STejun Heo */ 2181e74e3962STejun Heo unsigned long __per_cpu_offset[NR_CPUS] __read_mostly; 2182e74e3962STejun Heo EXPORT_SYMBOL(__per_cpu_offset); 2183e74e3962STejun Heo 2184c8826dd5STejun Heo static void * __init pcpu_dfl_fc_alloc(unsigned int cpu, size_t size, 2185c8826dd5STejun Heo size_t align) 2186c8826dd5STejun Heo { 2187999c17e3SSantosh Shilimkar return memblock_virt_alloc_from_nopanic( 2188999c17e3SSantosh Shilimkar size, align, __pa(MAX_DMA_ADDRESS)); 2189c8826dd5STejun Heo } 2190c8826dd5STejun Heo 2191c8826dd5STejun Heo static void __init pcpu_dfl_fc_free(void *ptr, size_t size) 2192c8826dd5STejun Heo { 2193999c17e3SSantosh Shilimkar memblock_free_early(__pa(ptr), size); 2194c8826dd5STejun Heo } 2195c8826dd5STejun Heo 2196e74e3962STejun Heo void __init setup_per_cpu_areas(void) 2197e74e3962STejun Heo { 2198e74e3962STejun Heo unsigned long delta; 2199e74e3962STejun Heo unsigned int cpu; 2200fb435d52STejun Heo int rc; 2201e74e3962STejun Heo 2202e74e3962STejun Heo /* 2203e74e3962STejun Heo * Always reserve area for module percpu variables. That's 2204e74e3962STejun Heo * what the legacy allocator did. 2205e74e3962STejun Heo */ 2206fb435d52STejun Heo rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, 2207c8826dd5STejun Heo PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, NULL, 2208c8826dd5STejun Heo pcpu_dfl_fc_alloc, pcpu_dfl_fc_free); 2209fb435d52STejun Heo if (rc < 0) 2210bbddff05STejun Heo panic("Failed to initialize percpu areas."); 2211e74e3962STejun Heo 2212e74e3962STejun Heo delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; 2213e74e3962STejun Heo for_each_possible_cpu(cpu) 2214fb435d52STejun Heo __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu]; 2215e74e3962STejun Heo } 2216e74e3962STejun Heo #endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */ 2217099a19d9STejun Heo 2218bbddff05STejun Heo #else /* CONFIG_SMP */ 2219bbddff05STejun Heo 2220bbddff05STejun Heo /* 2221bbddff05STejun Heo * UP percpu area setup. 2222bbddff05STejun Heo * 2223bbddff05STejun Heo * UP always uses km-based percpu allocator with identity mapping. 2224bbddff05STejun Heo * Static percpu variables are indistinguishable from the usual static 2225bbddff05STejun Heo * variables and don't require any special preparation. 2226bbddff05STejun Heo */ 2227bbddff05STejun Heo void __init setup_per_cpu_areas(void) 2228bbddff05STejun Heo { 2229bbddff05STejun Heo const size_t unit_size = 2230bbddff05STejun Heo roundup_pow_of_two(max_t(size_t, PCPU_MIN_UNIT_SIZE, 2231bbddff05STejun Heo PERCPU_DYNAMIC_RESERVE)); 2232bbddff05STejun Heo struct pcpu_alloc_info *ai; 2233bbddff05STejun Heo void *fc; 2234bbddff05STejun Heo 2235bbddff05STejun Heo ai = pcpu_alloc_alloc_info(1, 1); 2236999c17e3SSantosh Shilimkar fc = memblock_virt_alloc_from_nopanic(unit_size, 2237999c17e3SSantosh Shilimkar PAGE_SIZE, 2238999c17e3SSantosh Shilimkar __pa(MAX_DMA_ADDRESS)); 2239bbddff05STejun Heo if (!ai || !fc) 2240bbddff05STejun Heo panic("Failed to allocate memory for percpu areas."); 2241100d13c3SCatalin Marinas /* kmemleak tracks the percpu allocations separately */ 2242100d13c3SCatalin Marinas kmemleak_free(fc); 2243bbddff05STejun Heo 2244bbddff05STejun Heo ai->dyn_size = unit_size; 2245bbddff05STejun Heo ai->unit_size = unit_size; 2246bbddff05STejun Heo ai->atom_size = unit_size; 2247bbddff05STejun Heo ai->alloc_size = unit_size; 2248bbddff05STejun Heo ai->groups[0].nr_units = 1; 2249bbddff05STejun Heo ai->groups[0].cpu_map[0] = 0; 2250bbddff05STejun Heo 2251bbddff05STejun Heo if (pcpu_setup_first_chunk(ai, fc) < 0) 2252bbddff05STejun Heo panic("Failed to initialize percpu areas."); 2253bbddff05STejun Heo } 2254bbddff05STejun Heo 2255bbddff05STejun Heo #endif /* CONFIG_SMP */ 2256bbddff05STejun Heo 2257099a19d9STejun Heo /* 2258099a19d9STejun Heo * First and reserved chunks are initialized with temporary allocation 2259099a19d9STejun Heo * map in initdata so that they can be used before slab is online. 2260099a19d9STejun Heo * This function is called after slab is brought up and replaces those 2261099a19d9STejun Heo * with properly allocated maps. 2262099a19d9STejun Heo */ 2263099a19d9STejun Heo void __init percpu_init_late(void) 2264099a19d9STejun Heo { 2265099a19d9STejun Heo struct pcpu_chunk *target_chunks[] = 2266099a19d9STejun Heo { pcpu_first_chunk, pcpu_reserved_chunk, NULL }; 2267099a19d9STejun Heo struct pcpu_chunk *chunk; 2268099a19d9STejun Heo unsigned long flags; 2269099a19d9STejun Heo int i; 2270099a19d9STejun Heo 2271099a19d9STejun Heo for (i = 0; (chunk = target_chunks[i]); i++) { 2272099a19d9STejun Heo int *map; 2273099a19d9STejun Heo const size_t size = PERCPU_DYNAMIC_EARLY_SLOTS * sizeof(map[0]); 2274099a19d9STejun Heo 2275099a19d9STejun Heo BUILD_BUG_ON(size > PAGE_SIZE); 2276099a19d9STejun Heo 227790459ce0SBob Liu map = pcpu_mem_zalloc(size); 2278099a19d9STejun Heo BUG_ON(!map); 2279099a19d9STejun Heo 2280099a19d9STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 2281099a19d9STejun Heo memcpy(map, chunk->map, size); 2282099a19d9STejun Heo chunk->map = map; 2283099a19d9STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 2284099a19d9STejun Heo } 2285099a19d9STejun Heo } 22861a4d7607STejun Heo 22871a4d7607STejun Heo /* 22881a4d7607STejun Heo * Percpu allocator is initialized early during boot when neither slab or 22891a4d7607STejun Heo * workqueue is available. Plug async management until everything is up 22901a4d7607STejun Heo * and running. 22911a4d7607STejun Heo */ 22921a4d7607STejun Heo static int __init percpu_enable_async(void) 22931a4d7607STejun Heo { 22941a4d7607STejun Heo pcpu_async_enabled = true; 22951a4d7607STejun Heo return 0; 22961a4d7607STejun Heo } 22971a4d7607STejun Heo subsys_initcall(percpu_enable_async); 2298