1fbf59bc9STejun Heo /* 2fbf59bc9STejun Heo * linux/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 10fbf59bc9STejun Heo * areas. Percpu areas are allocated in chunks in vmalloc area. Each 112f39e637STejun Heo * chunk is consisted of boot-time determined number of units and the 122f39e637STejun Heo * first 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. 162f39e637STejun Heo * When a chunk is filled up, another chunk is allocated. ie. in 172f39e637STejun Heo * vmalloc area 18fbf59bc9STejun Heo * 19fbf59bc9STejun Heo * c0 c1 c2 20fbf59bc9STejun Heo * ------------------- ------------------- ------------ 21fbf59bc9STejun Heo * | u0 | u1 | u2 | u3 | | u0 | u1 | u2 | u3 | | u0 | u1 | u 22fbf59bc9STejun Heo * ------------------- ...... ------------------- .... ------------ 23fbf59bc9STejun Heo * 24fbf59bc9STejun Heo * Allocation is done in offset-size areas of single unit space. Ie, 25fbf59bc9STejun Heo * an area of 512 bytes at 6k in c1 occupies 512 bytes at 6k of c1:u0, 262f39e637STejun Heo * c1:u1, c1:u2 and c1:u3. On UMA, units corresponds directly to 272f39e637STejun Heo * cpus. On NUMA, the mapping can be non-linear and even sparse. 282f39e637STejun Heo * Percpu access can be done by configuring percpu base registers 292f39e637STejun Heo * according to cpu to unit mapping and pcpu_unit_size. 30fbf59bc9STejun Heo * 312f39e637STejun Heo * There are usually many small percpu allocations many of them being 322f39e637STejun Heo * as small as 4 bytes. The allocator organizes chunks into lists 33fbf59bc9STejun Heo * according to free size and tries to allocate from the fullest one. 34fbf59bc9STejun Heo * Each chunk keeps the maximum contiguous area size hint which is 35fbf59bc9STejun Heo * guaranteed to be eqaul to or larger than the maximum contiguous 36fbf59bc9STejun Heo * area in the chunk. This helps the allocator not to iterate the 37fbf59bc9STejun Heo * chunk maps unnecessarily. 38fbf59bc9STejun Heo * 39fbf59bc9STejun Heo * Allocation state in each chunk is kept using an array of integers 40fbf59bc9STejun Heo * on chunk->map. A positive value in the map represents a free 41fbf59bc9STejun Heo * region and negative allocated. Allocation inside a chunk is done 42fbf59bc9STejun Heo * by scanning this map sequentially and serving the first matching 43fbf59bc9STejun Heo * entry. This is mostly copied from the percpu_modalloc() allocator. 44e1b9aa3fSChristoph Lameter * Chunks can be determined from the address using the index field 45e1b9aa3fSChristoph Lameter * in the page struct. The index field contains a pointer to the chunk. 46fbf59bc9STejun Heo * 47fbf59bc9STejun Heo * To use this allocator, arch code should do the followings. 48fbf59bc9STejun Heo * 49e74e3962STejun Heo * - drop CONFIG_HAVE_LEGACY_PER_CPU_AREA 50fbf59bc9STejun Heo * 51fbf59bc9STejun Heo * - define __addr_to_pcpu_ptr() and __pcpu_ptr_to_addr() to translate 52e0100983STejun Heo * regular address to percpu pointer and back if they need to be 53e0100983STejun Heo * different from the default 54fbf59bc9STejun Heo * 558d408b4bSTejun Heo * - use pcpu_setup_first_chunk() during percpu area initialization to 568d408b4bSTejun Heo * setup the first chunk containing the kernel static percpu area 57fbf59bc9STejun Heo */ 58fbf59bc9STejun Heo 59fbf59bc9STejun Heo #include <linux/bitmap.h> 60fbf59bc9STejun Heo #include <linux/bootmem.h> 61fd1e8a1fSTejun Heo #include <linux/err.h> 62fbf59bc9STejun Heo #include <linux/list.h> 63a530b795STejun Heo #include <linux/log2.h> 64fbf59bc9STejun Heo #include <linux/mm.h> 65fbf59bc9STejun Heo #include <linux/module.h> 66fbf59bc9STejun Heo #include <linux/mutex.h> 67fbf59bc9STejun Heo #include <linux/percpu.h> 68fbf59bc9STejun Heo #include <linux/pfn.h> 69fbf59bc9STejun Heo #include <linux/slab.h> 70ccea34b5STejun Heo #include <linux/spinlock.h> 71fbf59bc9STejun Heo #include <linux/vmalloc.h> 72a56dbddfSTejun Heo #include <linux/workqueue.h> 73fbf59bc9STejun Heo 74fbf59bc9STejun Heo #include <asm/cacheflush.h> 75e0100983STejun Heo #include <asm/sections.h> 76fbf59bc9STejun Heo #include <asm/tlbflush.h> 77fbf59bc9STejun Heo 78fbf59bc9STejun Heo #define PCPU_SLOT_BASE_SHIFT 5 /* 1-31 shares the same slot */ 79fbf59bc9STejun Heo #define PCPU_DFL_MAP_ALLOC 16 /* start a map with 16 ents */ 80fbf59bc9STejun Heo 81e0100983STejun Heo /* default addr <-> pcpu_ptr mapping, override in asm/percpu.h if necessary */ 82e0100983STejun Heo #ifndef __addr_to_pcpu_ptr 83e0100983STejun Heo #define __addr_to_pcpu_ptr(addr) \ 84e0100983STejun Heo (void *)((unsigned long)(addr) - (unsigned long)pcpu_base_addr \ 85e0100983STejun Heo + (unsigned long)__per_cpu_start) 86e0100983STejun Heo #endif 87e0100983STejun Heo #ifndef __pcpu_ptr_to_addr 88e0100983STejun Heo #define __pcpu_ptr_to_addr(ptr) \ 89e0100983STejun Heo (void *)((unsigned long)(ptr) + (unsigned long)pcpu_base_addr \ 90e0100983STejun Heo - (unsigned long)__per_cpu_start) 91e0100983STejun Heo #endif 92e0100983STejun Heo 93fbf59bc9STejun Heo struct pcpu_chunk { 94fbf59bc9STejun Heo struct list_head list; /* linked to pcpu_slot lists */ 95fbf59bc9STejun Heo int free_size; /* free bytes in the chunk */ 96fbf59bc9STejun Heo int contig_hint; /* max contiguous size hint */ 97bba174f5STejun Heo void *base_addr; /* base address of this chunk */ 98fbf59bc9STejun Heo int map_used; /* # of map entries used */ 99fbf59bc9STejun Heo int map_alloc; /* # of map entries allocated */ 100fbf59bc9STejun Heo int *map; /* allocation map */ 1016563297cSTejun Heo struct vm_struct **vms; /* mapped vmalloc regions */ 1028d408b4bSTejun Heo bool immutable; /* no [de]population allowed */ 103ce3141a2STejun Heo unsigned long populated[]; /* populated bitmap */ 104fbf59bc9STejun Heo }; 105fbf59bc9STejun Heo 10640150d37STejun Heo static int pcpu_unit_pages __read_mostly; 10740150d37STejun Heo static int pcpu_unit_size __read_mostly; 1082f39e637STejun Heo static int pcpu_nr_units __read_mostly; 1096563297cSTejun Heo static int pcpu_atom_size __read_mostly; 11040150d37STejun Heo static int pcpu_nr_slots __read_mostly; 11140150d37STejun Heo static size_t pcpu_chunk_struct_size __read_mostly; 112fbf59bc9STejun Heo 1132f39e637STejun Heo /* cpus with the lowest and highest unit numbers */ 1142f39e637STejun Heo static unsigned int pcpu_first_unit_cpu __read_mostly; 1152f39e637STejun Heo static unsigned int pcpu_last_unit_cpu __read_mostly; 1162f39e637STejun Heo 117fbf59bc9STejun Heo /* the address of the first chunk which starts with the kernel static area */ 11840150d37STejun Heo void *pcpu_base_addr __read_mostly; 119fbf59bc9STejun Heo EXPORT_SYMBOL_GPL(pcpu_base_addr); 120fbf59bc9STejun Heo 121fb435d52STejun Heo static const int *pcpu_unit_map __read_mostly; /* cpu -> unit */ 122fb435d52STejun Heo const unsigned long *pcpu_unit_offsets __read_mostly; /* cpu -> unit offset */ 1232f39e637STejun Heo 1246563297cSTejun Heo /* group information, used for vm allocation */ 1256563297cSTejun Heo static int pcpu_nr_groups __read_mostly; 1266563297cSTejun Heo static const unsigned long *pcpu_group_offsets __read_mostly; 1276563297cSTejun Heo static const size_t *pcpu_group_sizes __read_mostly; 1286563297cSTejun Heo 129ae9e6bc9STejun Heo /* 130ae9e6bc9STejun Heo * The first chunk which always exists. Note that unlike other 131ae9e6bc9STejun Heo * chunks, this one can be allocated and mapped in several different 132ae9e6bc9STejun Heo * ways and thus often doesn't live in the vmalloc area. 133ae9e6bc9STejun Heo */ 134ae9e6bc9STejun Heo static struct pcpu_chunk *pcpu_first_chunk; 135ae9e6bc9STejun Heo 136ae9e6bc9STejun Heo /* 137ae9e6bc9STejun Heo * Optional reserved chunk. This chunk reserves part of the first 138ae9e6bc9STejun Heo * chunk and serves it for reserved allocations. The amount of 139ae9e6bc9STejun Heo * reserved offset is in pcpu_reserved_chunk_limit. When reserved 140ae9e6bc9STejun Heo * area doesn't exist, the following variables contain NULL and 0 141ae9e6bc9STejun Heo * respectively. 142ae9e6bc9STejun Heo */ 143edcb4639STejun Heo static struct pcpu_chunk *pcpu_reserved_chunk; 144edcb4639STejun Heo static int pcpu_reserved_chunk_limit; 145edcb4639STejun Heo 146fbf59bc9STejun Heo /* 147ccea34b5STejun Heo * Synchronization rules. 148fbf59bc9STejun Heo * 149ccea34b5STejun Heo * There are two locks - pcpu_alloc_mutex and pcpu_lock. The former 150ce3141a2STejun Heo * protects allocation/reclaim paths, chunks, populated bitmap and 151ce3141a2STejun Heo * vmalloc mapping. The latter is a spinlock and protects the index 152ce3141a2STejun Heo * data structures - chunk slots, chunks and area maps in chunks. 153fbf59bc9STejun Heo * 154ccea34b5STejun Heo * During allocation, pcpu_alloc_mutex is kept locked all the time and 155ccea34b5STejun Heo * pcpu_lock is grabbed and released as necessary. All actual memory 156403a91b1SJiri Kosina * allocations are done using GFP_KERNEL with pcpu_lock released. In 157403a91b1SJiri Kosina * general, percpu memory can't be allocated with irq off but 158403a91b1SJiri Kosina * irqsave/restore are still used in alloc path so that it can be used 159403a91b1SJiri Kosina * from early init path - sched_init() specifically. 160ccea34b5STejun Heo * 161ccea34b5STejun Heo * Free path accesses and alters only the index data structures, so it 162ccea34b5STejun Heo * can be safely called from atomic context. When memory needs to be 163ccea34b5STejun Heo * returned to the system, free path schedules reclaim_work which 164ccea34b5STejun Heo * grabs both pcpu_alloc_mutex and pcpu_lock, unlinks chunks to be 165ccea34b5STejun Heo * reclaimed, release both locks and frees the chunks. Note that it's 166ccea34b5STejun Heo * necessary to grab both locks to remove a chunk from circulation as 167ccea34b5STejun Heo * allocation path might be referencing the chunk with only 168ccea34b5STejun Heo * pcpu_alloc_mutex locked. 169fbf59bc9STejun Heo */ 170ccea34b5STejun Heo static DEFINE_MUTEX(pcpu_alloc_mutex); /* protects whole alloc and reclaim */ 171ccea34b5STejun Heo static DEFINE_SPINLOCK(pcpu_lock); /* protects index data structures */ 172fbf59bc9STejun Heo 17340150d37STejun Heo static struct list_head *pcpu_slot __read_mostly; /* chunk list slots */ 174fbf59bc9STejun Heo 175a56dbddfSTejun Heo /* reclaim work to release fully free chunks, scheduled from free path */ 176a56dbddfSTejun Heo static void pcpu_reclaim(struct work_struct *work); 177a56dbddfSTejun Heo static DECLARE_WORK(pcpu_reclaim_work, pcpu_reclaim); 178a56dbddfSTejun Heo 179d9b55eebSTejun Heo static int __pcpu_size_to_slot(int size) 180fbf59bc9STejun Heo { 181cae3aeb8STejun Heo int highbit = fls(size); /* size is in bytes */ 182fbf59bc9STejun Heo return max(highbit - PCPU_SLOT_BASE_SHIFT + 2, 1); 183fbf59bc9STejun Heo } 184fbf59bc9STejun Heo 185d9b55eebSTejun Heo static int pcpu_size_to_slot(int size) 186d9b55eebSTejun Heo { 187d9b55eebSTejun Heo if (size == pcpu_unit_size) 188d9b55eebSTejun Heo return pcpu_nr_slots - 1; 189d9b55eebSTejun Heo return __pcpu_size_to_slot(size); 190d9b55eebSTejun Heo } 191d9b55eebSTejun Heo 192fbf59bc9STejun Heo static int pcpu_chunk_slot(const struct pcpu_chunk *chunk) 193fbf59bc9STejun Heo { 194fbf59bc9STejun Heo if (chunk->free_size < sizeof(int) || chunk->contig_hint < sizeof(int)) 195fbf59bc9STejun Heo return 0; 196fbf59bc9STejun Heo 197fbf59bc9STejun Heo return pcpu_size_to_slot(chunk->free_size); 198fbf59bc9STejun Heo } 199fbf59bc9STejun Heo 200fbf59bc9STejun Heo static int pcpu_page_idx(unsigned int cpu, int page_idx) 201fbf59bc9STejun Heo { 2022f39e637STejun Heo return pcpu_unit_map[cpu] * pcpu_unit_pages + page_idx; 203fbf59bc9STejun Heo } 204fbf59bc9STejun Heo 205fbf59bc9STejun Heo static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk, 206fbf59bc9STejun Heo unsigned int cpu, int page_idx) 207fbf59bc9STejun Heo { 208bba174f5STejun Heo return (unsigned long)chunk->base_addr + pcpu_unit_offsets[cpu] + 209fb435d52STejun Heo (page_idx << PAGE_SHIFT); 210fbf59bc9STejun Heo } 211fbf59bc9STejun Heo 212ce3141a2STejun Heo static struct page *pcpu_chunk_page(struct pcpu_chunk *chunk, 213c8a51be4STejun Heo unsigned int cpu, int page_idx) 214fbf59bc9STejun Heo { 215ce3141a2STejun Heo /* must not be used on pre-mapped chunk */ 216ce3141a2STejun Heo WARN_ON(chunk->immutable); 217c8a51be4STejun Heo 218ce3141a2STejun Heo return vmalloc_to_page((void *)pcpu_chunk_addr(chunk, cpu, page_idx)); 219fbf59bc9STejun Heo } 220fbf59bc9STejun Heo 221e1b9aa3fSChristoph Lameter /* set the pointer to a chunk in a page struct */ 222e1b9aa3fSChristoph Lameter static void pcpu_set_page_chunk(struct page *page, struct pcpu_chunk *pcpu) 223e1b9aa3fSChristoph Lameter { 224e1b9aa3fSChristoph Lameter page->index = (unsigned long)pcpu; 225e1b9aa3fSChristoph Lameter } 226e1b9aa3fSChristoph Lameter 227e1b9aa3fSChristoph Lameter /* obtain pointer to a chunk from a page struct */ 228e1b9aa3fSChristoph Lameter static struct pcpu_chunk *pcpu_get_page_chunk(struct page *page) 229e1b9aa3fSChristoph Lameter { 230e1b9aa3fSChristoph Lameter return (struct pcpu_chunk *)page->index; 231e1b9aa3fSChristoph Lameter } 232e1b9aa3fSChristoph Lameter 233ce3141a2STejun Heo static void pcpu_next_unpop(struct pcpu_chunk *chunk, int *rs, int *re, int end) 234ce3141a2STejun Heo { 235ce3141a2STejun Heo *rs = find_next_zero_bit(chunk->populated, end, *rs); 236ce3141a2STejun Heo *re = find_next_bit(chunk->populated, end, *rs + 1); 237ce3141a2STejun Heo } 238ce3141a2STejun Heo 239ce3141a2STejun Heo static void pcpu_next_pop(struct pcpu_chunk *chunk, int *rs, int *re, int end) 240ce3141a2STejun Heo { 241ce3141a2STejun Heo *rs = find_next_bit(chunk->populated, end, *rs); 242ce3141a2STejun Heo *re = find_next_zero_bit(chunk->populated, end, *rs + 1); 243ce3141a2STejun Heo } 244ce3141a2STejun Heo 245ce3141a2STejun Heo /* 246ce3141a2STejun Heo * (Un)populated page region iterators. Iterate over (un)populated 247ce3141a2STejun Heo * page regions betwen @start and @end in @chunk. @rs and @re should 248ce3141a2STejun Heo * be integer variables and will be set to start and end page index of 249ce3141a2STejun Heo * the current region. 250ce3141a2STejun Heo */ 251ce3141a2STejun Heo #define pcpu_for_each_unpop_region(chunk, rs, re, start, end) \ 252ce3141a2STejun Heo for ((rs) = (start), pcpu_next_unpop((chunk), &(rs), &(re), (end)); \ 253ce3141a2STejun Heo (rs) < (re); \ 254ce3141a2STejun Heo (rs) = (re) + 1, pcpu_next_unpop((chunk), &(rs), &(re), (end))) 255ce3141a2STejun Heo 256ce3141a2STejun Heo #define pcpu_for_each_pop_region(chunk, rs, re, start, end) \ 257ce3141a2STejun Heo for ((rs) = (start), pcpu_next_pop((chunk), &(rs), &(re), (end)); \ 258ce3141a2STejun Heo (rs) < (re); \ 259ce3141a2STejun Heo (rs) = (re) + 1, pcpu_next_pop((chunk), &(rs), &(re), (end))) 260ce3141a2STejun Heo 261fbf59bc9STejun Heo /** 2621880d93bSTejun Heo * pcpu_mem_alloc - allocate memory 2631880d93bSTejun Heo * @size: bytes to allocate 264fbf59bc9STejun Heo * 2651880d93bSTejun Heo * Allocate @size bytes. If @size is smaller than PAGE_SIZE, 2661880d93bSTejun Heo * kzalloc() is used; otherwise, vmalloc() is used. The returned 2671880d93bSTejun Heo * memory is always zeroed. 268fbf59bc9STejun Heo * 269ccea34b5STejun Heo * CONTEXT: 270ccea34b5STejun Heo * Does GFP_KERNEL allocation. 271ccea34b5STejun Heo * 272fbf59bc9STejun Heo * RETURNS: 2731880d93bSTejun Heo * Pointer to the allocated area on success, NULL on failure. 274fbf59bc9STejun Heo */ 2751880d93bSTejun Heo static void *pcpu_mem_alloc(size_t size) 276fbf59bc9STejun Heo { 277fbf59bc9STejun Heo if (size <= PAGE_SIZE) 2781880d93bSTejun Heo return kzalloc(size, GFP_KERNEL); 2791880d93bSTejun Heo else { 2801880d93bSTejun Heo void *ptr = vmalloc(size); 2811880d93bSTejun Heo if (ptr) 2821880d93bSTejun Heo memset(ptr, 0, size); 2831880d93bSTejun Heo return ptr; 2841880d93bSTejun Heo } 2851880d93bSTejun Heo } 286fbf59bc9STejun Heo 2871880d93bSTejun Heo /** 2881880d93bSTejun Heo * pcpu_mem_free - free memory 2891880d93bSTejun Heo * @ptr: memory to free 2901880d93bSTejun Heo * @size: size of the area 2911880d93bSTejun Heo * 2921880d93bSTejun Heo * Free @ptr. @ptr should have been allocated using pcpu_mem_alloc(). 2931880d93bSTejun Heo */ 2941880d93bSTejun Heo static void pcpu_mem_free(void *ptr, size_t size) 2951880d93bSTejun Heo { 2961880d93bSTejun Heo if (size <= PAGE_SIZE) 2971880d93bSTejun Heo kfree(ptr); 2981880d93bSTejun Heo else 2991880d93bSTejun Heo vfree(ptr); 300fbf59bc9STejun Heo } 301fbf59bc9STejun Heo 302fbf59bc9STejun Heo /** 303fbf59bc9STejun Heo * pcpu_chunk_relocate - put chunk in the appropriate chunk slot 304fbf59bc9STejun Heo * @chunk: chunk of interest 305fbf59bc9STejun Heo * @oslot: the previous slot it was on 306fbf59bc9STejun Heo * 307fbf59bc9STejun Heo * This function is called after an allocation or free changed @chunk. 308fbf59bc9STejun Heo * New slot according to the changed state is determined and @chunk is 309edcb4639STejun Heo * moved to the slot. Note that the reserved chunk is never put on 310edcb4639STejun Heo * chunk slots. 311ccea34b5STejun Heo * 312ccea34b5STejun Heo * CONTEXT: 313ccea34b5STejun Heo * pcpu_lock. 314fbf59bc9STejun Heo */ 315fbf59bc9STejun Heo static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot) 316fbf59bc9STejun Heo { 317fbf59bc9STejun Heo int nslot = pcpu_chunk_slot(chunk); 318fbf59bc9STejun Heo 319edcb4639STejun Heo if (chunk != pcpu_reserved_chunk && oslot != nslot) { 320fbf59bc9STejun Heo if (oslot < nslot) 321fbf59bc9STejun Heo list_move(&chunk->list, &pcpu_slot[nslot]); 322fbf59bc9STejun Heo else 323fbf59bc9STejun Heo list_move_tail(&chunk->list, &pcpu_slot[nslot]); 324fbf59bc9STejun Heo } 325fbf59bc9STejun Heo } 326fbf59bc9STejun Heo 327fbf59bc9STejun Heo /** 328e1b9aa3fSChristoph Lameter * pcpu_chunk_addr_search - determine chunk containing specified address 329e1b9aa3fSChristoph Lameter * @addr: address for which the chunk needs to be determined. 330ccea34b5STejun Heo * 331fbf59bc9STejun Heo * RETURNS: 332fbf59bc9STejun Heo * The address of the found chunk. 333fbf59bc9STejun Heo */ 334fbf59bc9STejun Heo static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr) 335fbf59bc9STejun Heo { 336bba174f5STejun Heo void *first_start = pcpu_first_chunk->base_addr; 337fbf59bc9STejun Heo 338ae9e6bc9STejun Heo /* is it in the first chunk? */ 33979ba6ac8STejun Heo if (addr >= first_start && addr < first_start + pcpu_unit_size) { 340ae9e6bc9STejun Heo /* is it in the reserved area? */ 341ae9e6bc9STejun Heo if (addr < first_start + pcpu_reserved_chunk_limit) 342edcb4639STejun Heo return pcpu_reserved_chunk; 343ae9e6bc9STejun Heo return pcpu_first_chunk; 344edcb4639STejun Heo } 345edcb4639STejun Heo 34604a13c7cSTejun Heo /* 34704a13c7cSTejun Heo * The address is relative to unit0 which might be unused and 34804a13c7cSTejun Heo * thus unmapped. Offset the address to the unit space of the 34904a13c7cSTejun Heo * current processor before looking it up in the vmalloc 35004a13c7cSTejun Heo * space. Note that any possible cpu id can be used here, so 35104a13c7cSTejun Heo * there's no need to worry about preemption or cpu hotplug. 35204a13c7cSTejun Heo */ 3535579fd7eSTejun Heo addr += pcpu_unit_offsets[raw_smp_processor_id()]; 354e1b9aa3fSChristoph Lameter return pcpu_get_page_chunk(vmalloc_to_page(addr)); 355fbf59bc9STejun Heo } 356fbf59bc9STejun Heo 357fbf59bc9STejun Heo /** 358*833af842STejun Heo * pcpu_need_to_extend - determine whether chunk area map needs to be extended 359*833af842STejun Heo * @chunk: chunk of interest 3609f7dcf22STejun Heo * 361*833af842STejun Heo * Determine whether area map of @chunk needs to be extended to 362*833af842STejun Heo * accomodate a new allocation. 3639f7dcf22STejun Heo * 364ccea34b5STejun Heo * CONTEXT: 365*833af842STejun Heo * pcpu_lock. 366ccea34b5STejun Heo * 3679f7dcf22STejun Heo * RETURNS: 368*833af842STejun Heo * New target map allocation length if extension is necessary, 0 369*833af842STejun Heo * otherwise. 3709f7dcf22STejun Heo */ 371*833af842STejun Heo static int pcpu_need_to_extend(struct pcpu_chunk *chunk) 3729f7dcf22STejun Heo { 3739f7dcf22STejun Heo int new_alloc; 3749f7dcf22STejun Heo 3759f7dcf22STejun Heo if (chunk->map_alloc >= chunk->map_used + 2) 3769f7dcf22STejun Heo return 0; 3779f7dcf22STejun Heo 3789f7dcf22STejun Heo new_alloc = PCPU_DFL_MAP_ALLOC; 3799f7dcf22STejun Heo while (new_alloc < chunk->map_used + 2) 3809f7dcf22STejun Heo new_alloc *= 2; 3819f7dcf22STejun Heo 382*833af842STejun Heo return new_alloc; 383ccea34b5STejun Heo } 384ccea34b5STejun Heo 385*833af842STejun Heo /** 386*833af842STejun Heo * pcpu_extend_area_map - extend area map of a chunk 387*833af842STejun Heo * @chunk: chunk of interest 388*833af842STejun Heo * @new_alloc: new target allocation length of the area map 389*833af842STejun Heo * 390*833af842STejun Heo * Extend area map of @chunk to have @new_alloc entries. 391*833af842STejun Heo * 392*833af842STejun Heo * CONTEXT: 393*833af842STejun Heo * Does GFP_KERNEL allocation. Grabs and releases pcpu_lock. 394*833af842STejun Heo * 395*833af842STejun Heo * RETURNS: 396*833af842STejun Heo * 0 on success, -errno on failure. 397ccea34b5STejun Heo */ 398*833af842STejun Heo static int pcpu_extend_area_map(struct pcpu_chunk *chunk, int new_alloc) 399*833af842STejun Heo { 400*833af842STejun Heo int *old = NULL, *new = NULL; 401*833af842STejun Heo size_t old_size = 0, new_size = new_alloc * sizeof(new[0]); 402*833af842STejun Heo unsigned long flags; 4039f7dcf22STejun Heo 404*833af842STejun Heo new = pcpu_mem_alloc(new_size); 405*833af842STejun Heo if (!new) 406*833af842STejun Heo return -ENOMEM; 407*833af842STejun Heo 408*833af842STejun Heo /* acquire pcpu_lock and switch to new area map */ 409*833af842STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 410*833af842STejun Heo 411*833af842STejun Heo if (new_alloc <= chunk->map_alloc) 412*833af842STejun Heo goto out_unlock; 413*833af842STejun Heo 414*833af842STejun Heo old_size = chunk->map_alloc * sizeof(chunk->map[0]); 415*833af842STejun Heo memcpy(new, chunk->map, old_size); 4169f7dcf22STejun Heo 4179f7dcf22STejun Heo /* 4189f7dcf22STejun Heo * map_alloc < PCPU_DFL_MAP_ALLOC indicates that the chunk is 4199f7dcf22STejun Heo * one of the first chunks and still using static map. 4209f7dcf22STejun Heo */ 4219f7dcf22STejun Heo if (chunk->map_alloc >= PCPU_DFL_MAP_ALLOC) 422*833af842STejun Heo old = chunk->map; 4239f7dcf22STejun Heo 4249f7dcf22STejun Heo chunk->map_alloc = new_alloc; 4259f7dcf22STejun Heo chunk->map = new; 426*833af842STejun Heo new = NULL; 427*833af842STejun Heo 428*833af842STejun Heo out_unlock: 429*833af842STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 430*833af842STejun Heo 431*833af842STejun Heo /* 432*833af842STejun Heo * pcpu_mem_free() might end up calling vfree() which uses 433*833af842STejun Heo * IRQ-unsafe lock and thus can't be called under pcpu_lock. 434*833af842STejun Heo */ 435*833af842STejun Heo pcpu_mem_free(old, old_size); 436*833af842STejun Heo pcpu_mem_free(new, new_size); 437*833af842STejun Heo 4389f7dcf22STejun Heo return 0; 4399f7dcf22STejun Heo } 4409f7dcf22STejun Heo 4419f7dcf22STejun Heo /** 442fbf59bc9STejun Heo * pcpu_split_block - split a map block 443fbf59bc9STejun Heo * @chunk: chunk of interest 444fbf59bc9STejun Heo * @i: index of map block to split 445cae3aeb8STejun Heo * @head: head size in bytes (can be 0) 446cae3aeb8STejun Heo * @tail: tail size in bytes (can be 0) 447fbf59bc9STejun Heo * 448fbf59bc9STejun Heo * Split the @i'th map block into two or three blocks. If @head is 449fbf59bc9STejun Heo * non-zero, @head bytes block is inserted before block @i moving it 450fbf59bc9STejun Heo * to @i+1 and reducing its size by @head bytes. 451fbf59bc9STejun Heo * 452fbf59bc9STejun Heo * If @tail is non-zero, the target block, which can be @i or @i+1 453fbf59bc9STejun Heo * depending on @head, is reduced by @tail bytes and @tail byte block 454fbf59bc9STejun Heo * is inserted after the target block. 455fbf59bc9STejun Heo * 4569f7dcf22STejun Heo * @chunk->map must have enough free slots to accomodate the split. 457ccea34b5STejun Heo * 458ccea34b5STejun Heo * CONTEXT: 459ccea34b5STejun Heo * pcpu_lock. 460fbf59bc9STejun Heo */ 4619f7dcf22STejun Heo static void pcpu_split_block(struct pcpu_chunk *chunk, int i, 4629f7dcf22STejun Heo int head, int tail) 463fbf59bc9STejun Heo { 464fbf59bc9STejun Heo int nr_extra = !!head + !!tail; 465fbf59bc9STejun Heo 4669f7dcf22STejun Heo BUG_ON(chunk->map_alloc < chunk->map_used + nr_extra); 467fbf59bc9STejun Heo 4689f7dcf22STejun Heo /* insert new subblocks */ 469fbf59bc9STejun Heo memmove(&chunk->map[i + nr_extra], &chunk->map[i], 470fbf59bc9STejun Heo sizeof(chunk->map[0]) * (chunk->map_used - i)); 471fbf59bc9STejun Heo chunk->map_used += nr_extra; 472fbf59bc9STejun Heo 473fbf59bc9STejun Heo if (head) { 474fbf59bc9STejun Heo chunk->map[i + 1] = chunk->map[i] - head; 475fbf59bc9STejun Heo chunk->map[i++] = head; 476fbf59bc9STejun Heo } 477fbf59bc9STejun Heo if (tail) { 478fbf59bc9STejun Heo chunk->map[i++] -= tail; 479fbf59bc9STejun Heo chunk->map[i] = tail; 480fbf59bc9STejun Heo } 481fbf59bc9STejun Heo } 482fbf59bc9STejun Heo 483fbf59bc9STejun Heo /** 484fbf59bc9STejun Heo * pcpu_alloc_area - allocate area from a pcpu_chunk 485fbf59bc9STejun Heo * @chunk: chunk of interest 486cae3aeb8STejun Heo * @size: wanted size in bytes 487fbf59bc9STejun Heo * @align: wanted align 488fbf59bc9STejun Heo * 489fbf59bc9STejun Heo * Try to allocate @size bytes area aligned at @align from @chunk. 490fbf59bc9STejun Heo * Note that this function only allocates the offset. It doesn't 491fbf59bc9STejun Heo * populate or map the area. 492fbf59bc9STejun Heo * 4939f7dcf22STejun Heo * @chunk->map must have at least two free slots. 4949f7dcf22STejun Heo * 495ccea34b5STejun Heo * CONTEXT: 496ccea34b5STejun Heo * pcpu_lock. 497ccea34b5STejun Heo * 498fbf59bc9STejun Heo * RETURNS: 4999f7dcf22STejun Heo * Allocated offset in @chunk on success, -1 if no matching area is 5009f7dcf22STejun Heo * found. 501fbf59bc9STejun Heo */ 502fbf59bc9STejun Heo static int pcpu_alloc_area(struct pcpu_chunk *chunk, int size, int align) 503fbf59bc9STejun Heo { 504fbf59bc9STejun Heo int oslot = pcpu_chunk_slot(chunk); 505fbf59bc9STejun Heo int max_contig = 0; 506fbf59bc9STejun Heo int i, off; 507fbf59bc9STejun Heo 508fbf59bc9STejun Heo for (i = 0, off = 0; i < chunk->map_used; off += abs(chunk->map[i++])) { 509fbf59bc9STejun Heo bool is_last = i + 1 == chunk->map_used; 510fbf59bc9STejun Heo int head, tail; 511fbf59bc9STejun Heo 512fbf59bc9STejun Heo /* extra for alignment requirement */ 513fbf59bc9STejun Heo head = ALIGN(off, align) - off; 514fbf59bc9STejun Heo BUG_ON(i == 0 && head != 0); 515fbf59bc9STejun Heo 516fbf59bc9STejun Heo if (chunk->map[i] < 0) 517fbf59bc9STejun Heo continue; 518fbf59bc9STejun Heo if (chunk->map[i] < head + size) { 519fbf59bc9STejun Heo max_contig = max(chunk->map[i], max_contig); 520fbf59bc9STejun Heo continue; 521fbf59bc9STejun Heo } 522fbf59bc9STejun Heo 523fbf59bc9STejun Heo /* 524fbf59bc9STejun Heo * If head is small or the previous block is free, 525fbf59bc9STejun Heo * merge'em. Note that 'small' is defined as smaller 526fbf59bc9STejun Heo * than sizeof(int), which is very small but isn't too 527fbf59bc9STejun Heo * uncommon for percpu allocations. 528fbf59bc9STejun Heo */ 529fbf59bc9STejun Heo if (head && (head < sizeof(int) || chunk->map[i - 1] > 0)) { 530fbf59bc9STejun Heo if (chunk->map[i - 1] > 0) 531fbf59bc9STejun Heo chunk->map[i - 1] += head; 532fbf59bc9STejun Heo else { 533fbf59bc9STejun Heo chunk->map[i - 1] -= head; 534fbf59bc9STejun Heo chunk->free_size -= head; 535fbf59bc9STejun Heo } 536fbf59bc9STejun Heo chunk->map[i] -= head; 537fbf59bc9STejun Heo off += head; 538fbf59bc9STejun Heo head = 0; 539fbf59bc9STejun Heo } 540fbf59bc9STejun Heo 541fbf59bc9STejun Heo /* if tail is small, just keep it around */ 542fbf59bc9STejun Heo tail = chunk->map[i] - head - size; 543fbf59bc9STejun Heo if (tail < sizeof(int)) 544fbf59bc9STejun Heo tail = 0; 545fbf59bc9STejun Heo 546fbf59bc9STejun Heo /* split if warranted */ 547fbf59bc9STejun Heo if (head || tail) { 5489f7dcf22STejun Heo pcpu_split_block(chunk, i, head, tail); 549fbf59bc9STejun Heo if (head) { 550fbf59bc9STejun Heo i++; 551fbf59bc9STejun Heo off += head; 552fbf59bc9STejun Heo max_contig = max(chunk->map[i - 1], max_contig); 553fbf59bc9STejun Heo } 554fbf59bc9STejun Heo if (tail) 555fbf59bc9STejun Heo max_contig = max(chunk->map[i + 1], max_contig); 556fbf59bc9STejun Heo } 557fbf59bc9STejun Heo 558fbf59bc9STejun Heo /* update hint and mark allocated */ 559fbf59bc9STejun Heo if (is_last) 560fbf59bc9STejun Heo chunk->contig_hint = max_contig; /* fully scanned */ 561fbf59bc9STejun Heo else 562fbf59bc9STejun Heo chunk->contig_hint = max(chunk->contig_hint, 563fbf59bc9STejun Heo max_contig); 564fbf59bc9STejun Heo 565fbf59bc9STejun Heo chunk->free_size -= chunk->map[i]; 566fbf59bc9STejun Heo chunk->map[i] = -chunk->map[i]; 567fbf59bc9STejun Heo 568fbf59bc9STejun Heo pcpu_chunk_relocate(chunk, oslot); 569fbf59bc9STejun Heo return off; 570fbf59bc9STejun Heo } 571fbf59bc9STejun Heo 572fbf59bc9STejun Heo chunk->contig_hint = max_contig; /* fully scanned */ 573fbf59bc9STejun Heo pcpu_chunk_relocate(chunk, oslot); 574fbf59bc9STejun Heo 5759f7dcf22STejun Heo /* tell the upper layer that this chunk has no matching area */ 5769f7dcf22STejun Heo return -1; 577fbf59bc9STejun Heo } 578fbf59bc9STejun Heo 579fbf59bc9STejun Heo /** 580fbf59bc9STejun Heo * pcpu_free_area - free area to a pcpu_chunk 581fbf59bc9STejun Heo * @chunk: chunk of interest 582fbf59bc9STejun Heo * @freeme: offset of area to free 583fbf59bc9STejun Heo * 584fbf59bc9STejun Heo * Free area starting from @freeme to @chunk. Note that this function 585fbf59bc9STejun Heo * only modifies the allocation map. It doesn't depopulate or unmap 586fbf59bc9STejun Heo * the area. 587ccea34b5STejun Heo * 588ccea34b5STejun Heo * CONTEXT: 589ccea34b5STejun Heo * pcpu_lock. 590fbf59bc9STejun Heo */ 591fbf59bc9STejun Heo static void pcpu_free_area(struct pcpu_chunk *chunk, int freeme) 592fbf59bc9STejun Heo { 593fbf59bc9STejun Heo int oslot = pcpu_chunk_slot(chunk); 594fbf59bc9STejun Heo int i, off; 595fbf59bc9STejun Heo 596fbf59bc9STejun Heo for (i = 0, off = 0; i < chunk->map_used; off += abs(chunk->map[i++])) 597fbf59bc9STejun Heo if (off == freeme) 598fbf59bc9STejun Heo break; 599fbf59bc9STejun Heo BUG_ON(off != freeme); 600fbf59bc9STejun Heo BUG_ON(chunk->map[i] > 0); 601fbf59bc9STejun Heo 602fbf59bc9STejun Heo chunk->map[i] = -chunk->map[i]; 603fbf59bc9STejun Heo chunk->free_size += chunk->map[i]; 604fbf59bc9STejun Heo 605fbf59bc9STejun Heo /* merge with previous? */ 606fbf59bc9STejun Heo if (i > 0 && chunk->map[i - 1] >= 0) { 607fbf59bc9STejun Heo chunk->map[i - 1] += chunk->map[i]; 608fbf59bc9STejun Heo chunk->map_used--; 609fbf59bc9STejun Heo memmove(&chunk->map[i], &chunk->map[i + 1], 610fbf59bc9STejun Heo (chunk->map_used - i) * sizeof(chunk->map[0])); 611fbf59bc9STejun Heo i--; 612fbf59bc9STejun Heo } 613fbf59bc9STejun Heo /* merge with next? */ 614fbf59bc9STejun Heo if (i + 1 < chunk->map_used && chunk->map[i + 1] >= 0) { 615fbf59bc9STejun Heo chunk->map[i] += chunk->map[i + 1]; 616fbf59bc9STejun Heo chunk->map_used--; 617fbf59bc9STejun Heo memmove(&chunk->map[i + 1], &chunk->map[i + 2], 618fbf59bc9STejun Heo (chunk->map_used - (i + 1)) * sizeof(chunk->map[0])); 619fbf59bc9STejun Heo } 620fbf59bc9STejun Heo 621fbf59bc9STejun Heo chunk->contig_hint = max(chunk->map[i], chunk->contig_hint); 622fbf59bc9STejun Heo pcpu_chunk_relocate(chunk, oslot); 623fbf59bc9STejun Heo } 624fbf59bc9STejun Heo 625fbf59bc9STejun Heo /** 626ce3141a2STejun Heo * pcpu_get_pages_and_bitmap - get temp pages array and bitmap 627fbf59bc9STejun Heo * @chunk: chunk of interest 628ce3141a2STejun Heo * @bitmapp: output parameter for bitmap 629ce3141a2STejun Heo * @may_alloc: may allocate the array 630fbf59bc9STejun Heo * 631ce3141a2STejun Heo * Returns pointer to array of pointers to struct page and bitmap, 632ce3141a2STejun Heo * both of which can be indexed with pcpu_page_idx(). The returned 633ce3141a2STejun Heo * array is cleared to zero and *@bitmapp is copied from 634ce3141a2STejun Heo * @chunk->populated. Note that there is only one array and bitmap 635ce3141a2STejun Heo * and access exclusion is the caller's responsibility. 636ce3141a2STejun Heo * 637ce3141a2STejun Heo * CONTEXT: 638ce3141a2STejun Heo * pcpu_alloc_mutex and does GFP_KERNEL allocation if @may_alloc. 639ce3141a2STejun Heo * Otherwise, don't care. 640ce3141a2STejun Heo * 641ce3141a2STejun Heo * RETURNS: 642ce3141a2STejun Heo * Pointer to temp pages array on success, NULL on failure. 643fbf59bc9STejun Heo */ 644ce3141a2STejun Heo static struct page **pcpu_get_pages_and_bitmap(struct pcpu_chunk *chunk, 645ce3141a2STejun Heo unsigned long **bitmapp, 646ce3141a2STejun Heo bool may_alloc) 647ce3141a2STejun Heo { 648ce3141a2STejun Heo static struct page **pages; 649ce3141a2STejun Heo static unsigned long *bitmap; 6502f39e637STejun Heo size_t pages_size = pcpu_nr_units * pcpu_unit_pages * sizeof(pages[0]); 651ce3141a2STejun Heo size_t bitmap_size = BITS_TO_LONGS(pcpu_unit_pages) * 652ce3141a2STejun Heo sizeof(unsigned long); 653ce3141a2STejun Heo 654ce3141a2STejun Heo if (!pages || !bitmap) { 655ce3141a2STejun Heo if (may_alloc && !pages) 656ce3141a2STejun Heo pages = pcpu_mem_alloc(pages_size); 657ce3141a2STejun Heo if (may_alloc && !bitmap) 658ce3141a2STejun Heo bitmap = pcpu_mem_alloc(bitmap_size); 659ce3141a2STejun Heo if (!pages || !bitmap) 660ce3141a2STejun Heo return NULL; 661ce3141a2STejun Heo } 662ce3141a2STejun Heo 663ce3141a2STejun Heo memset(pages, 0, pages_size); 664ce3141a2STejun Heo bitmap_copy(bitmap, chunk->populated, pcpu_unit_pages); 665ce3141a2STejun Heo 666ce3141a2STejun Heo *bitmapp = bitmap; 667ce3141a2STejun Heo return pages; 668ce3141a2STejun Heo } 669ce3141a2STejun Heo 670ce3141a2STejun Heo /** 671ce3141a2STejun Heo * pcpu_free_pages - free pages which were allocated for @chunk 672ce3141a2STejun Heo * @chunk: chunk pages were allocated for 673ce3141a2STejun Heo * @pages: array of pages to be freed, indexed by pcpu_page_idx() 674ce3141a2STejun Heo * @populated: populated bitmap 675ce3141a2STejun Heo * @page_start: page index of the first page to be freed 676ce3141a2STejun Heo * @page_end: page index of the last page to be freed + 1 677ce3141a2STejun Heo * 678ce3141a2STejun Heo * Free pages [@page_start and @page_end) in @pages for all units. 679ce3141a2STejun Heo * The pages were allocated for @chunk. 680ce3141a2STejun Heo */ 681ce3141a2STejun Heo static void pcpu_free_pages(struct pcpu_chunk *chunk, 682ce3141a2STejun Heo struct page **pages, unsigned long *populated, 683ce3141a2STejun Heo int page_start, int page_end) 684ce3141a2STejun Heo { 685ce3141a2STejun Heo unsigned int cpu; 686ce3141a2STejun Heo int i; 687ce3141a2STejun Heo 688ce3141a2STejun Heo for_each_possible_cpu(cpu) { 689ce3141a2STejun Heo for (i = page_start; i < page_end; i++) { 690ce3141a2STejun Heo struct page *page = pages[pcpu_page_idx(cpu, i)]; 691ce3141a2STejun Heo 692ce3141a2STejun Heo if (page) 693ce3141a2STejun Heo __free_page(page); 694ce3141a2STejun Heo } 695ce3141a2STejun Heo } 696ce3141a2STejun Heo } 697ce3141a2STejun Heo 698ce3141a2STejun Heo /** 699ce3141a2STejun Heo * pcpu_alloc_pages - allocates pages for @chunk 700ce3141a2STejun Heo * @chunk: target chunk 701ce3141a2STejun Heo * @pages: array to put the allocated pages into, indexed by pcpu_page_idx() 702ce3141a2STejun Heo * @populated: populated bitmap 703ce3141a2STejun Heo * @page_start: page index of the first page to be allocated 704ce3141a2STejun Heo * @page_end: page index of the last page to be allocated + 1 705ce3141a2STejun Heo * 706ce3141a2STejun Heo * Allocate pages [@page_start,@page_end) into @pages for all units. 707ce3141a2STejun Heo * The allocation is for @chunk. Percpu core doesn't care about the 708ce3141a2STejun Heo * content of @pages and will pass it verbatim to pcpu_map_pages(). 709ce3141a2STejun Heo */ 710ce3141a2STejun Heo static int pcpu_alloc_pages(struct pcpu_chunk *chunk, 711ce3141a2STejun Heo struct page **pages, unsigned long *populated, 712ce3141a2STejun Heo int page_start, int page_end) 713ce3141a2STejun Heo { 714ce3141a2STejun Heo const gfp_t gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_COLD; 715ce3141a2STejun Heo unsigned int cpu; 716ce3141a2STejun Heo int i; 717ce3141a2STejun Heo 718ce3141a2STejun Heo for_each_possible_cpu(cpu) { 719ce3141a2STejun Heo for (i = page_start; i < page_end; i++) { 720ce3141a2STejun Heo struct page **pagep = &pages[pcpu_page_idx(cpu, i)]; 721ce3141a2STejun Heo 722ce3141a2STejun Heo *pagep = alloc_pages_node(cpu_to_node(cpu), gfp, 0); 723ce3141a2STejun Heo if (!*pagep) { 724ce3141a2STejun Heo pcpu_free_pages(chunk, pages, populated, 725ce3141a2STejun Heo page_start, page_end); 726ce3141a2STejun Heo return -ENOMEM; 727ce3141a2STejun Heo } 728ce3141a2STejun Heo } 729ce3141a2STejun Heo } 730ce3141a2STejun Heo return 0; 731ce3141a2STejun Heo } 732ce3141a2STejun Heo 733ce3141a2STejun Heo /** 734ce3141a2STejun Heo * pcpu_pre_unmap_flush - flush cache prior to unmapping 735ce3141a2STejun Heo * @chunk: chunk the regions to be flushed belongs to 736ce3141a2STejun Heo * @page_start: page index of the first page to be flushed 737ce3141a2STejun Heo * @page_end: page index of the last page to be flushed + 1 738ce3141a2STejun Heo * 739ce3141a2STejun Heo * Pages in [@page_start,@page_end) of @chunk are about to be 740ce3141a2STejun Heo * unmapped. Flush cache. As each flushing trial can be very 741ce3141a2STejun Heo * expensive, issue flush on the whole region at once rather than 742ce3141a2STejun Heo * doing it for each cpu. This could be an overkill but is more 743ce3141a2STejun Heo * scalable. 744ce3141a2STejun Heo */ 745ce3141a2STejun Heo static void pcpu_pre_unmap_flush(struct pcpu_chunk *chunk, 746ce3141a2STejun Heo int page_start, int page_end) 747fbf59bc9STejun Heo { 7482f39e637STejun Heo flush_cache_vunmap( 7492f39e637STejun Heo pcpu_chunk_addr(chunk, pcpu_first_unit_cpu, page_start), 7502f39e637STejun Heo pcpu_chunk_addr(chunk, pcpu_last_unit_cpu, page_end)); 751ce3141a2STejun Heo } 752fbf59bc9STejun Heo 753ce3141a2STejun Heo static void __pcpu_unmap_pages(unsigned long addr, int nr_pages) 754ce3141a2STejun Heo { 755ce3141a2STejun Heo unmap_kernel_range_noflush(addr, nr_pages << PAGE_SHIFT); 756ce3141a2STejun Heo } 757fbf59bc9STejun Heo 758ce3141a2STejun Heo /** 759ce3141a2STejun Heo * pcpu_unmap_pages - unmap pages out of a pcpu_chunk 760ce3141a2STejun Heo * @chunk: chunk of interest 761ce3141a2STejun Heo * @pages: pages array which can be used to pass information to free 762ce3141a2STejun Heo * @populated: populated bitmap 763fbf59bc9STejun Heo * @page_start: page index of the first page to unmap 764fbf59bc9STejun Heo * @page_end: page index of the last page to unmap + 1 765fbf59bc9STejun Heo * 766fbf59bc9STejun Heo * For each cpu, unmap pages [@page_start,@page_end) out of @chunk. 767ce3141a2STejun Heo * Corresponding elements in @pages were cleared by the caller and can 768ce3141a2STejun Heo * be used to carry information to pcpu_free_pages() which will be 769ce3141a2STejun Heo * called after all unmaps are finished. The caller should call 770ce3141a2STejun Heo * proper pre/post flush functions. 771fbf59bc9STejun Heo */ 772ce3141a2STejun Heo static void pcpu_unmap_pages(struct pcpu_chunk *chunk, 773ce3141a2STejun Heo struct page **pages, unsigned long *populated, 774ce3141a2STejun Heo int page_start, int page_end) 775fbf59bc9STejun Heo { 776fbf59bc9STejun Heo unsigned int cpu; 777ce3141a2STejun Heo int i; 778fbf59bc9STejun Heo 779ce3141a2STejun Heo for_each_possible_cpu(cpu) { 780ce3141a2STejun Heo for (i = page_start; i < page_end; i++) { 781ce3141a2STejun Heo struct page *page; 782fbf59bc9STejun Heo 783ce3141a2STejun Heo page = pcpu_chunk_page(chunk, cpu, i); 784ce3141a2STejun Heo WARN_ON(!page); 785ce3141a2STejun Heo pages[pcpu_page_idx(cpu, i)] = page; 786ce3141a2STejun Heo } 787ce3141a2STejun Heo __pcpu_unmap_pages(pcpu_chunk_addr(chunk, cpu, page_start), 788ce3141a2STejun Heo page_end - page_start); 789ce3141a2STejun Heo } 790ce3141a2STejun Heo 791ce3141a2STejun Heo for (i = page_start; i < page_end; i++) 792ce3141a2STejun Heo __clear_bit(i, populated); 793ce3141a2STejun Heo } 794ce3141a2STejun Heo 795ce3141a2STejun Heo /** 796ce3141a2STejun Heo * pcpu_post_unmap_tlb_flush - flush TLB after unmapping 797ce3141a2STejun Heo * @chunk: pcpu_chunk the regions to be flushed belong to 798ce3141a2STejun Heo * @page_start: page index of the first page to be flushed 799ce3141a2STejun Heo * @page_end: page index of the last page to be flushed + 1 800ce3141a2STejun Heo * 801ce3141a2STejun Heo * Pages [@page_start,@page_end) of @chunk have been unmapped. Flush 802ce3141a2STejun Heo * TLB for the regions. This can be skipped if the area is to be 803ce3141a2STejun Heo * returned to vmalloc as vmalloc will handle TLB flushing lazily. 804ce3141a2STejun Heo * 805ce3141a2STejun Heo * As with pcpu_pre_unmap_flush(), TLB flushing also is done at once 806ce3141a2STejun Heo * for the whole region. 807fbf59bc9STejun Heo */ 808ce3141a2STejun Heo static void pcpu_post_unmap_tlb_flush(struct pcpu_chunk *chunk, 809ce3141a2STejun Heo int page_start, int page_end) 810ce3141a2STejun Heo { 8112f39e637STejun Heo flush_tlb_kernel_range( 8122f39e637STejun Heo pcpu_chunk_addr(chunk, pcpu_first_unit_cpu, page_start), 8132f39e637STejun Heo pcpu_chunk_addr(chunk, pcpu_last_unit_cpu, page_end)); 814fbf59bc9STejun Heo } 815fbf59bc9STejun Heo 816c8a51be4STejun Heo static int __pcpu_map_pages(unsigned long addr, struct page **pages, 817c8a51be4STejun Heo int nr_pages) 818c8a51be4STejun Heo { 819c8a51be4STejun Heo return map_kernel_range_noflush(addr, nr_pages << PAGE_SHIFT, 820c8a51be4STejun Heo PAGE_KERNEL, pages); 821c8a51be4STejun Heo } 822c8a51be4STejun Heo 823c8a51be4STejun Heo /** 824ce3141a2STejun Heo * pcpu_map_pages - map pages into a pcpu_chunk 825c8a51be4STejun Heo * @chunk: chunk of interest 826ce3141a2STejun Heo * @pages: pages array containing pages to be mapped 827ce3141a2STejun Heo * @populated: populated bitmap 828c8a51be4STejun Heo * @page_start: page index of the first page to map 829c8a51be4STejun Heo * @page_end: page index of the last page to map + 1 830c8a51be4STejun Heo * 831ce3141a2STejun Heo * For each cpu, map pages [@page_start,@page_end) into @chunk. The 832ce3141a2STejun Heo * caller is responsible for calling pcpu_post_map_flush() after all 833ce3141a2STejun Heo * mappings are complete. 834ce3141a2STejun Heo * 835ce3141a2STejun Heo * This function is responsible for setting corresponding bits in 836ce3141a2STejun Heo * @chunk->populated bitmap and whatever is necessary for reverse 837ce3141a2STejun Heo * lookup (addr -> chunk). 838c8a51be4STejun Heo */ 839ce3141a2STejun Heo static int pcpu_map_pages(struct pcpu_chunk *chunk, 840ce3141a2STejun Heo struct page **pages, unsigned long *populated, 841ce3141a2STejun Heo int page_start, int page_end) 842c8a51be4STejun Heo { 843ce3141a2STejun Heo unsigned int cpu, tcpu; 844ce3141a2STejun Heo int i, err; 845c8a51be4STejun Heo 846c8a51be4STejun Heo for_each_possible_cpu(cpu) { 847c8a51be4STejun Heo err = __pcpu_map_pages(pcpu_chunk_addr(chunk, cpu, page_start), 848ce3141a2STejun Heo &pages[pcpu_page_idx(cpu, page_start)], 849c8a51be4STejun Heo page_end - page_start); 850c8a51be4STejun Heo if (err < 0) 851ce3141a2STejun Heo goto err; 852ce3141a2STejun Heo } 853ce3141a2STejun Heo 854ce3141a2STejun Heo /* mapping successful, link chunk and mark populated */ 855ce3141a2STejun Heo for (i = page_start; i < page_end; i++) { 856fbf59bc9STejun Heo for_each_possible_cpu(cpu) 857ce3141a2STejun Heo pcpu_set_page_chunk(pages[pcpu_page_idx(cpu, i)], 858ce3141a2STejun Heo chunk); 859ce3141a2STejun Heo __set_bit(i, populated); 860ce3141a2STejun Heo } 861fbf59bc9STejun Heo 862ce3141a2STejun Heo return 0; 863ce3141a2STejun Heo 864ce3141a2STejun Heo err: 865ce3141a2STejun Heo for_each_possible_cpu(tcpu) { 866ce3141a2STejun Heo if (tcpu == cpu) 867ce3141a2STejun Heo break; 868ce3141a2STejun Heo __pcpu_unmap_pages(pcpu_chunk_addr(chunk, tcpu, page_start), 869ce3141a2STejun Heo page_end - page_start); 870ce3141a2STejun Heo } 871c8a51be4STejun Heo return err; 872c8a51be4STejun Heo } 873c8a51be4STejun Heo 874ce3141a2STejun Heo /** 875ce3141a2STejun Heo * pcpu_post_map_flush - flush cache after mapping 876ce3141a2STejun Heo * @chunk: pcpu_chunk the regions to be flushed belong to 877ce3141a2STejun Heo * @page_start: page index of the first page to be flushed 878ce3141a2STejun Heo * @page_end: page index of the last page to be flushed + 1 879ce3141a2STejun Heo * 880ce3141a2STejun Heo * Pages [@page_start,@page_end) of @chunk have been mapped. Flush 881ce3141a2STejun Heo * cache. 882ce3141a2STejun Heo * 883ce3141a2STejun Heo * As with pcpu_pre_unmap_flush(), TLB flushing also is done at once 884ce3141a2STejun Heo * for the whole region. 885ce3141a2STejun Heo */ 886ce3141a2STejun Heo static void pcpu_post_map_flush(struct pcpu_chunk *chunk, 887ce3141a2STejun Heo int page_start, int page_end) 888ce3141a2STejun Heo { 8892f39e637STejun Heo flush_cache_vmap( 8902f39e637STejun Heo pcpu_chunk_addr(chunk, pcpu_first_unit_cpu, page_start), 8912f39e637STejun Heo pcpu_chunk_addr(chunk, pcpu_last_unit_cpu, page_end)); 892fbf59bc9STejun Heo } 893fbf59bc9STejun Heo 894fbf59bc9STejun Heo /** 895fbf59bc9STejun Heo * pcpu_depopulate_chunk - depopulate and unmap an area of a pcpu_chunk 896fbf59bc9STejun Heo * @chunk: chunk to depopulate 897fbf59bc9STejun Heo * @off: offset to the area to depopulate 898cae3aeb8STejun Heo * @size: size of the area to depopulate in bytes 899fbf59bc9STejun Heo * @flush: whether to flush cache and tlb or not 900fbf59bc9STejun Heo * 901fbf59bc9STejun Heo * For each cpu, depopulate and unmap pages [@page_start,@page_end) 902fbf59bc9STejun Heo * from @chunk. If @flush is true, vcache is flushed before unmapping 903fbf59bc9STejun Heo * and tlb after. 904ccea34b5STejun Heo * 905ccea34b5STejun Heo * CONTEXT: 906ccea34b5STejun Heo * pcpu_alloc_mutex. 907fbf59bc9STejun Heo */ 908ce3141a2STejun Heo static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size) 909fbf59bc9STejun Heo { 910fbf59bc9STejun Heo int page_start = PFN_DOWN(off); 911fbf59bc9STejun Heo int page_end = PFN_UP(off + size); 912ce3141a2STejun Heo struct page **pages; 913ce3141a2STejun Heo unsigned long *populated; 914ce3141a2STejun Heo int rs, re; 915fbf59bc9STejun Heo 916ce3141a2STejun Heo /* quick path, check whether it's empty already */ 917ce3141a2STejun Heo pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) { 918ce3141a2STejun Heo if (rs == page_start && re == page_end) 919ce3141a2STejun Heo return; 920ce3141a2STejun Heo break; 921fbf59bc9STejun Heo } 922fbf59bc9STejun Heo 923ce3141a2STejun Heo /* immutable chunks can't be depopulated */ 9248d408b4bSTejun Heo WARN_ON(chunk->immutable); 9258d408b4bSTejun Heo 926fbf59bc9STejun Heo /* 927ce3141a2STejun Heo * If control reaches here, there must have been at least one 928ce3141a2STejun Heo * successful population attempt so the temp pages array must 929ce3141a2STejun Heo * be available now. 930fbf59bc9STejun Heo */ 931ce3141a2STejun Heo pages = pcpu_get_pages_and_bitmap(chunk, &populated, false); 932ce3141a2STejun Heo BUG_ON(!pages); 933fbf59bc9STejun Heo 934ce3141a2STejun Heo /* unmap and free */ 935ce3141a2STejun Heo pcpu_pre_unmap_flush(chunk, page_start, page_end); 936fbf59bc9STejun Heo 937ce3141a2STejun Heo pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end) 938ce3141a2STejun Heo pcpu_unmap_pages(chunk, pages, populated, rs, re); 939ce3141a2STejun Heo 940ce3141a2STejun Heo /* no need to flush tlb, vmalloc will handle it lazily */ 941ce3141a2STejun Heo 942ce3141a2STejun Heo pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end) 943ce3141a2STejun Heo pcpu_free_pages(chunk, pages, populated, rs, re); 944ce3141a2STejun Heo 945ce3141a2STejun Heo /* commit new bitmap */ 946ce3141a2STejun Heo bitmap_copy(chunk->populated, populated, pcpu_unit_pages); 947fbf59bc9STejun Heo } 948fbf59bc9STejun Heo 949fbf59bc9STejun Heo /** 950fbf59bc9STejun Heo * pcpu_populate_chunk - populate and map an area of a pcpu_chunk 951fbf59bc9STejun Heo * @chunk: chunk of interest 952fbf59bc9STejun Heo * @off: offset to the area to populate 953cae3aeb8STejun Heo * @size: size of the area to populate in bytes 954fbf59bc9STejun Heo * 955fbf59bc9STejun Heo * For each cpu, populate and map pages [@page_start,@page_end) into 956fbf59bc9STejun Heo * @chunk. The area is cleared on return. 957ccea34b5STejun Heo * 958ccea34b5STejun Heo * CONTEXT: 959ccea34b5STejun Heo * pcpu_alloc_mutex, does GFP_KERNEL allocation. 960fbf59bc9STejun Heo */ 961fbf59bc9STejun Heo static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size) 962fbf59bc9STejun Heo { 963fbf59bc9STejun Heo int page_start = PFN_DOWN(off); 964fbf59bc9STejun Heo int page_end = PFN_UP(off + size); 965ce3141a2STejun Heo int free_end = page_start, unmap_end = page_start; 966ce3141a2STejun Heo struct page **pages; 967ce3141a2STejun Heo unsigned long *populated; 968fbf59bc9STejun Heo unsigned int cpu; 969ce3141a2STejun Heo int rs, re, rc; 970fbf59bc9STejun Heo 971ce3141a2STejun Heo /* quick path, check whether all pages are already there */ 972ce3141a2STejun Heo pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end) { 973ce3141a2STejun Heo if (rs == page_start && re == page_end) 974ce3141a2STejun Heo goto clear; 975ce3141a2STejun Heo break; 976fbf59bc9STejun Heo } 977fbf59bc9STejun Heo 978ce3141a2STejun Heo /* need to allocate and map pages, this chunk can't be immutable */ 979ce3141a2STejun Heo WARN_ON(chunk->immutable); 980fbf59bc9STejun Heo 981ce3141a2STejun Heo pages = pcpu_get_pages_and_bitmap(chunk, &populated, true); 982ce3141a2STejun Heo if (!pages) 983fbf59bc9STejun Heo return -ENOMEM; 984fbf59bc9STejun Heo 985ce3141a2STejun Heo /* alloc and map */ 986ce3141a2STejun Heo pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) { 987ce3141a2STejun Heo rc = pcpu_alloc_pages(chunk, pages, populated, rs, re); 988ce3141a2STejun Heo if (rc) 989ce3141a2STejun Heo goto err_free; 990ce3141a2STejun Heo free_end = re; 991fbf59bc9STejun Heo } 992fbf59bc9STejun Heo 993ce3141a2STejun Heo pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) { 994ce3141a2STejun Heo rc = pcpu_map_pages(chunk, pages, populated, rs, re); 995ce3141a2STejun Heo if (rc) 996ce3141a2STejun Heo goto err_unmap; 997ce3141a2STejun Heo unmap_end = re; 998ce3141a2STejun Heo } 999ce3141a2STejun Heo pcpu_post_map_flush(chunk, page_start, page_end); 1000fbf59bc9STejun Heo 1001ce3141a2STejun Heo /* commit new bitmap */ 1002ce3141a2STejun Heo bitmap_copy(chunk->populated, populated, pcpu_unit_pages); 1003ce3141a2STejun Heo clear: 1004fbf59bc9STejun Heo for_each_possible_cpu(cpu) 10052f39e637STejun Heo memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size); 1006fbf59bc9STejun Heo return 0; 1007ce3141a2STejun Heo 1008ce3141a2STejun Heo err_unmap: 1009ce3141a2STejun Heo pcpu_pre_unmap_flush(chunk, page_start, unmap_end); 1010ce3141a2STejun Heo pcpu_for_each_unpop_region(chunk, rs, re, page_start, unmap_end) 1011ce3141a2STejun Heo pcpu_unmap_pages(chunk, pages, populated, rs, re); 1012ce3141a2STejun Heo pcpu_post_unmap_tlb_flush(chunk, page_start, unmap_end); 1013ce3141a2STejun Heo err_free: 1014ce3141a2STejun Heo pcpu_for_each_unpop_region(chunk, rs, re, page_start, free_end) 1015ce3141a2STejun Heo pcpu_free_pages(chunk, pages, populated, rs, re); 1016ce3141a2STejun Heo return rc; 1017fbf59bc9STejun Heo } 1018fbf59bc9STejun Heo 1019fbf59bc9STejun Heo static void free_pcpu_chunk(struct pcpu_chunk *chunk) 1020fbf59bc9STejun Heo { 1021fbf59bc9STejun Heo if (!chunk) 1022fbf59bc9STejun Heo return; 10236563297cSTejun Heo if (chunk->vms) 10246563297cSTejun Heo pcpu_free_vm_areas(chunk->vms, pcpu_nr_groups); 10251880d93bSTejun Heo pcpu_mem_free(chunk->map, chunk->map_alloc * sizeof(chunk->map[0])); 1026fbf59bc9STejun Heo kfree(chunk); 1027fbf59bc9STejun Heo } 1028fbf59bc9STejun Heo 1029fbf59bc9STejun Heo static struct pcpu_chunk *alloc_pcpu_chunk(void) 1030fbf59bc9STejun Heo { 1031fbf59bc9STejun Heo struct pcpu_chunk *chunk; 1032fbf59bc9STejun Heo 1033fbf59bc9STejun Heo chunk = kzalloc(pcpu_chunk_struct_size, GFP_KERNEL); 1034fbf59bc9STejun Heo if (!chunk) 1035fbf59bc9STejun Heo return NULL; 1036fbf59bc9STejun Heo 10371880d93bSTejun Heo chunk->map = pcpu_mem_alloc(PCPU_DFL_MAP_ALLOC * sizeof(chunk->map[0])); 1038fbf59bc9STejun Heo chunk->map_alloc = PCPU_DFL_MAP_ALLOC; 1039fbf59bc9STejun Heo chunk->map[chunk->map_used++] = pcpu_unit_size; 1040fbf59bc9STejun Heo 10416563297cSTejun Heo chunk->vms = pcpu_get_vm_areas(pcpu_group_offsets, pcpu_group_sizes, 10426563297cSTejun Heo pcpu_nr_groups, pcpu_atom_size, 10436563297cSTejun Heo GFP_KERNEL); 10446563297cSTejun Heo if (!chunk->vms) { 1045fbf59bc9STejun Heo free_pcpu_chunk(chunk); 1046fbf59bc9STejun Heo return NULL; 1047fbf59bc9STejun Heo } 1048fbf59bc9STejun Heo 1049fbf59bc9STejun Heo INIT_LIST_HEAD(&chunk->list); 1050fbf59bc9STejun Heo chunk->free_size = pcpu_unit_size; 1051fbf59bc9STejun Heo chunk->contig_hint = pcpu_unit_size; 10526563297cSTejun Heo chunk->base_addr = chunk->vms[0]->addr - pcpu_group_offsets[0]; 1053fbf59bc9STejun Heo 1054fbf59bc9STejun Heo return chunk; 1055fbf59bc9STejun Heo } 1056fbf59bc9STejun Heo 1057fbf59bc9STejun Heo /** 1058edcb4639STejun Heo * pcpu_alloc - the percpu allocator 1059cae3aeb8STejun Heo * @size: size of area to allocate in bytes 1060fbf59bc9STejun Heo * @align: alignment of area (max PAGE_SIZE) 1061edcb4639STejun Heo * @reserved: allocate from the reserved chunk if available 1062fbf59bc9STejun Heo * 1063ccea34b5STejun Heo * Allocate percpu area of @size bytes aligned at @align. 1064ccea34b5STejun Heo * 1065ccea34b5STejun Heo * CONTEXT: 1066ccea34b5STejun Heo * Does GFP_KERNEL allocation. 1067fbf59bc9STejun Heo * 1068fbf59bc9STejun Heo * RETURNS: 1069fbf59bc9STejun Heo * Percpu pointer to the allocated area on success, NULL on failure. 1070fbf59bc9STejun Heo */ 1071edcb4639STejun Heo static void *pcpu_alloc(size_t size, size_t align, bool reserved) 1072fbf59bc9STejun Heo { 1073f2badb0cSTejun Heo static int warn_limit = 10; 1074fbf59bc9STejun Heo struct pcpu_chunk *chunk; 1075f2badb0cSTejun Heo const char *err; 1076*833af842STejun Heo int slot, off, new_alloc; 1077403a91b1SJiri Kosina unsigned long flags; 1078fbf59bc9STejun Heo 10798d408b4bSTejun Heo if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE)) { 1080fbf59bc9STejun Heo WARN(true, "illegal size (%zu) or align (%zu) for " 1081fbf59bc9STejun Heo "percpu allocation\n", size, align); 1082fbf59bc9STejun Heo return NULL; 1083fbf59bc9STejun Heo } 1084fbf59bc9STejun Heo 1085ccea34b5STejun Heo mutex_lock(&pcpu_alloc_mutex); 1086403a91b1SJiri Kosina spin_lock_irqsave(&pcpu_lock, flags); 1087fbf59bc9STejun Heo 1088edcb4639STejun Heo /* serve reserved allocations from the reserved chunk if available */ 1089edcb4639STejun Heo if (reserved && pcpu_reserved_chunk) { 1090edcb4639STejun Heo chunk = pcpu_reserved_chunk; 1091*833af842STejun Heo 1092*833af842STejun Heo if (size > chunk->contig_hint) { 1093*833af842STejun Heo err = "alloc from reserved chunk failed"; 1094ccea34b5STejun Heo goto fail_unlock; 1095f2badb0cSTejun Heo } 1096*833af842STejun Heo 1097*833af842STejun Heo while ((new_alloc = pcpu_need_to_extend(chunk))) { 1098*833af842STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 1099*833af842STejun Heo if (pcpu_extend_area_map(chunk, new_alloc) < 0) { 1100*833af842STejun Heo err = "failed to extend area map of reserved chunk"; 1101*833af842STejun Heo goto fail_unlock_mutex; 1102*833af842STejun Heo } 1103*833af842STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 1104*833af842STejun Heo } 1105*833af842STejun Heo 1106edcb4639STejun Heo off = pcpu_alloc_area(chunk, size, align); 1107edcb4639STejun Heo if (off >= 0) 1108edcb4639STejun Heo goto area_found; 1109*833af842STejun Heo 1110f2badb0cSTejun Heo err = "alloc from reserved chunk failed"; 1111ccea34b5STejun Heo goto fail_unlock; 1112edcb4639STejun Heo } 1113edcb4639STejun Heo 1114ccea34b5STejun Heo restart: 1115edcb4639STejun Heo /* search through normal chunks */ 1116fbf59bc9STejun Heo for (slot = pcpu_size_to_slot(size); slot < pcpu_nr_slots; slot++) { 1117fbf59bc9STejun Heo list_for_each_entry(chunk, &pcpu_slot[slot], list) { 1118fbf59bc9STejun Heo if (size > chunk->contig_hint) 1119fbf59bc9STejun Heo continue; 1120ccea34b5STejun Heo 1121*833af842STejun Heo new_alloc = pcpu_need_to_extend(chunk); 1122*833af842STejun Heo if (new_alloc) { 1123*833af842STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 1124*833af842STejun Heo if (pcpu_extend_area_map(chunk, 1125*833af842STejun Heo new_alloc) < 0) { 1126f2badb0cSTejun Heo err = "failed to extend area map"; 1127*833af842STejun Heo goto fail_unlock_mutex; 1128*833af842STejun Heo } 1129*833af842STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 1130*833af842STejun Heo /* 1131*833af842STejun Heo * pcpu_lock has been dropped, need to 1132*833af842STejun Heo * restart cpu_slot list walking. 1133*833af842STejun Heo */ 1134*833af842STejun Heo goto restart; 1135ccea34b5STejun Heo } 1136ccea34b5STejun Heo 1137fbf59bc9STejun Heo off = pcpu_alloc_area(chunk, size, align); 1138fbf59bc9STejun Heo if (off >= 0) 1139fbf59bc9STejun Heo goto area_found; 1140fbf59bc9STejun Heo } 1141fbf59bc9STejun Heo } 1142fbf59bc9STejun Heo 1143fbf59bc9STejun Heo /* hmmm... no space left, create a new chunk */ 1144403a91b1SJiri Kosina spin_unlock_irqrestore(&pcpu_lock, flags); 1145ccea34b5STejun Heo 1146fbf59bc9STejun Heo chunk = alloc_pcpu_chunk(); 1147f2badb0cSTejun Heo if (!chunk) { 1148f2badb0cSTejun Heo err = "failed to allocate new chunk"; 1149ccea34b5STejun Heo goto fail_unlock_mutex; 1150f2badb0cSTejun Heo } 1151ccea34b5STejun Heo 1152403a91b1SJiri Kosina spin_lock_irqsave(&pcpu_lock, flags); 1153fbf59bc9STejun Heo pcpu_chunk_relocate(chunk, -1); 1154ccea34b5STejun Heo goto restart; 1155fbf59bc9STejun Heo 1156fbf59bc9STejun Heo area_found: 1157403a91b1SJiri Kosina spin_unlock_irqrestore(&pcpu_lock, flags); 1158ccea34b5STejun Heo 1159fbf59bc9STejun Heo /* populate, map and clear the area */ 1160fbf59bc9STejun Heo if (pcpu_populate_chunk(chunk, off, size)) { 1161403a91b1SJiri Kosina spin_lock_irqsave(&pcpu_lock, flags); 1162fbf59bc9STejun Heo pcpu_free_area(chunk, off); 1163f2badb0cSTejun Heo err = "failed to populate"; 1164ccea34b5STejun Heo goto fail_unlock; 1165fbf59bc9STejun Heo } 1166fbf59bc9STejun Heo 1167ccea34b5STejun Heo mutex_unlock(&pcpu_alloc_mutex); 1168ccea34b5STejun Heo 1169bba174f5STejun Heo /* return address relative to base address */ 1170bba174f5STejun Heo return __addr_to_pcpu_ptr(chunk->base_addr + off); 1171ccea34b5STejun Heo 1172ccea34b5STejun Heo fail_unlock: 1173403a91b1SJiri Kosina spin_unlock_irqrestore(&pcpu_lock, flags); 1174ccea34b5STejun Heo fail_unlock_mutex: 1175ccea34b5STejun Heo mutex_unlock(&pcpu_alloc_mutex); 1176f2badb0cSTejun Heo if (warn_limit) { 1177f2badb0cSTejun Heo pr_warning("PERCPU: allocation failed, size=%zu align=%zu, " 1178f2badb0cSTejun Heo "%s\n", size, align, err); 1179f2badb0cSTejun Heo dump_stack(); 1180f2badb0cSTejun Heo if (!--warn_limit) 1181f2badb0cSTejun Heo pr_info("PERCPU: limit reached, disable warning\n"); 1182f2badb0cSTejun Heo } 1183ccea34b5STejun Heo return NULL; 1184fbf59bc9STejun Heo } 1185edcb4639STejun Heo 1186edcb4639STejun Heo /** 1187edcb4639STejun Heo * __alloc_percpu - allocate dynamic percpu area 1188edcb4639STejun Heo * @size: size of area to allocate in bytes 1189edcb4639STejun Heo * @align: alignment of area (max PAGE_SIZE) 1190edcb4639STejun Heo * 1191edcb4639STejun Heo * Allocate percpu area of @size bytes aligned at @align. Might 1192edcb4639STejun Heo * sleep. Might trigger writeouts. 1193edcb4639STejun Heo * 1194ccea34b5STejun Heo * CONTEXT: 1195ccea34b5STejun Heo * Does GFP_KERNEL allocation. 1196ccea34b5STejun Heo * 1197edcb4639STejun Heo * RETURNS: 1198edcb4639STejun Heo * Percpu pointer to the allocated area on success, NULL on failure. 1199edcb4639STejun Heo */ 1200edcb4639STejun Heo void *__alloc_percpu(size_t size, size_t align) 1201edcb4639STejun Heo { 1202edcb4639STejun Heo return pcpu_alloc(size, align, false); 1203edcb4639STejun Heo } 1204fbf59bc9STejun Heo EXPORT_SYMBOL_GPL(__alloc_percpu); 1205fbf59bc9STejun Heo 1206edcb4639STejun Heo /** 1207edcb4639STejun Heo * __alloc_reserved_percpu - allocate reserved percpu area 1208edcb4639STejun Heo * @size: size of area to allocate in bytes 1209edcb4639STejun Heo * @align: alignment of area (max PAGE_SIZE) 1210edcb4639STejun Heo * 1211edcb4639STejun Heo * Allocate percpu area of @size bytes aligned at @align from reserved 1212edcb4639STejun Heo * percpu area if arch has set it up; otherwise, allocation is served 1213edcb4639STejun Heo * from the same dynamic area. Might sleep. Might trigger writeouts. 1214edcb4639STejun Heo * 1215ccea34b5STejun Heo * CONTEXT: 1216ccea34b5STejun Heo * Does GFP_KERNEL allocation. 1217ccea34b5STejun Heo * 1218edcb4639STejun Heo * RETURNS: 1219edcb4639STejun Heo * Percpu pointer to the allocated area on success, NULL on failure. 1220edcb4639STejun Heo */ 1221edcb4639STejun Heo void *__alloc_reserved_percpu(size_t size, size_t align) 1222edcb4639STejun Heo { 1223edcb4639STejun Heo return pcpu_alloc(size, align, true); 1224edcb4639STejun Heo } 1225edcb4639STejun Heo 1226a56dbddfSTejun Heo /** 1227a56dbddfSTejun Heo * pcpu_reclaim - reclaim fully free chunks, workqueue function 1228a56dbddfSTejun Heo * @work: unused 1229a56dbddfSTejun Heo * 1230a56dbddfSTejun Heo * Reclaim all fully free chunks except for the first one. 1231ccea34b5STejun Heo * 1232ccea34b5STejun Heo * CONTEXT: 1233ccea34b5STejun Heo * workqueue context. 1234a56dbddfSTejun Heo */ 1235a56dbddfSTejun Heo static void pcpu_reclaim(struct work_struct *work) 1236fbf59bc9STejun Heo { 1237a56dbddfSTejun Heo LIST_HEAD(todo); 1238a56dbddfSTejun Heo struct list_head *head = &pcpu_slot[pcpu_nr_slots - 1]; 1239a56dbddfSTejun Heo struct pcpu_chunk *chunk, *next; 1240a56dbddfSTejun Heo 1241ccea34b5STejun Heo mutex_lock(&pcpu_alloc_mutex); 1242ccea34b5STejun Heo spin_lock_irq(&pcpu_lock); 1243a56dbddfSTejun Heo 1244a56dbddfSTejun Heo list_for_each_entry_safe(chunk, next, head, list) { 12458d408b4bSTejun Heo WARN_ON(chunk->immutable); 1246a56dbddfSTejun Heo 1247a56dbddfSTejun Heo /* spare the first one */ 1248a56dbddfSTejun Heo if (chunk == list_first_entry(head, struct pcpu_chunk, list)) 1249a56dbddfSTejun Heo continue; 1250a56dbddfSTejun Heo 1251a56dbddfSTejun Heo list_move(&chunk->list, &todo); 1252a56dbddfSTejun Heo } 1253a56dbddfSTejun Heo 1254ccea34b5STejun Heo spin_unlock_irq(&pcpu_lock); 1255a56dbddfSTejun Heo 1256a56dbddfSTejun Heo list_for_each_entry_safe(chunk, next, &todo, list) { 1257ce3141a2STejun Heo pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size); 1258fbf59bc9STejun Heo free_pcpu_chunk(chunk); 1259fbf59bc9STejun Heo } 1260971f3918STejun Heo 1261971f3918STejun Heo mutex_unlock(&pcpu_alloc_mutex); 1262a56dbddfSTejun Heo } 1263fbf59bc9STejun Heo 1264fbf59bc9STejun Heo /** 1265fbf59bc9STejun Heo * free_percpu - free percpu area 1266fbf59bc9STejun Heo * @ptr: pointer to area to free 1267fbf59bc9STejun Heo * 1268ccea34b5STejun Heo * Free percpu area @ptr. 1269ccea34b5STejun Heo * 1270ccea34b5STejun Heo * CONTEXT: 1271ccea34b5STejun Heo * Can be called from atomic context. 1272fbf59bc9STejun Heo */ 1273fbf59bc9STejun Heo void free_percpu(void *ptr) 1274fbf59bc9STejun Heo { 1275fbf59bc9STejun Heo void *addr = __pcpu_ptr_to_addr(ptr); 1276fbf59bc9STejun Heo struct pcpu_chunk *chunk; 1277ccea34b5STejun Heo unsigned long flags; 1278fbf59bc9STejun Heo int off; 1279fbf59bc9STejun Heo 1280fbf59bc9STejun Heo if (!ptr) 1281fbf59bc9STejun Heo return; 1282fbf59bc9STejun Heo 1283ccea34b5STejun Heo spin_lock_irqsave(&pcpu_lock, flags); 1284fbf59bc9STejun Heo 1285fbf59bc9STejun Heo chunk = pcpu_chunk_addr_search(addr); 1286bba174f5STejun Heo off = addr - chunk->base_addr; 1287fbf59bc9STejun Heo 1288fbf59bc9STejun Heo pcpu_free_area(chunk, off); 1289fbf59bc9STejun Heo 1290a56dbddfSTejun Heo /* if there are more than one fully free chunks, wake up grim reaper */ 1291fbf59bc9STejun Heo if (chunk->free_size == pcpu_unit_size) { 1292fbf59bc9STejun Heo struct pcpu_chunk *pos; 1293fbf59bc9STejun Heo 1294a56dbddfSTejun Heo list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list) 1295fbf59bc9STejun Heo if (pos != chunk) { 1296a56dbddfSTejun Heo schedule_work(&pcpu_reclaim_work); 1297fbf59bc9STejun Heo break; 1298fbf59bc9STejun Heo } 1299fbf59bc9STejun Heo } 1300fbf59bc9STejun Heo 1301ccea34b5STejun Heo spin_unlock_irqrestore(&pcpu_lock, flags); 1302fbf59bc9STejun Heo } 1303fbf59bc9STejun Heo EXPORT_SYMBOL_GPL(free_percpu); 1304fbf59bc9STejun Heo 1305033e48fbSTejun Heo static inline size_t pcpu_calc_fc_sizes(size_t static_size, 1306033e48fbSTejun Heo size_t reserved_size, 1307033e48fbSTejun Heo ssize_t *dyn_sizep) 1308033e48fbSTejun Heo { 1309033e48fbSTejun Heo size_t size_sum; 1310033e48fbSTejun Heo 1311033e48fbSTejun Heo size_sum = PFN_ALIGN(static_size + reserved_size + 1312033e48fbSTejun Heo (*dyn_sizep >= 0 ? *dyn_sizep : 0)); 1313033e48fbSTejun Heo if (*dyn_sizep != 0) 1314033e48fbSTejun Heo *dyn_sizep = size_sum - static_size - reserved_size; 1315033e48fbSTejun Heo 1316033e48fbSTejun Heo return size_sum; 1317033e48fbSTejun Heo } 1318033e48fbSTejun Heo 1319fbf59bc9STejun Heo /** 1320fd1e8a1fSTejun Heo * pcpu_alloc_alloc_info - allocate percpu allocation info 1321fd1e8a1fSTejun Heo * @nr_groups: the number of groups 1322fd1e8a1fSTejun Heo * @nr_units: the number of units 1323033e48fbSTejun Heo * 1324fd1e8a1fSTejun Heo * Allocate ai which is large enough for @nr_groups groups containing 1325fd1e8a1fSTejun Heo * @nr_units units. The returned ai's groups[0].cpu_map points to the 1326fd1e8a1fSTejun Heo * cpu_map array which is long enough for @nr_units and filled with 1327fd1e8a1fSTejun Heo * NR_CPUS. It's the caller's responsibility to initialize cpu_map 1328fd1e8a1fSTejun Heo * pointer of other groups. 1329033e48fbSTejun Heo * 1330033e48fbSTejun Heo * RETURNS: 1331fd1e8a1fSTejun Heo * Pointer to the allocated pcpu_alloc_info on success, NULL on 1332fd1e8a1fSTejun Heo * failure. 1333033e48fbSTejun Heo */ 1334fd1e8a1fSTejun Heo struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, 1335fd1e8a1fSTejun Heo int nr_units) 1336fd1e8a1fSTejun Heo { 1337fd1e8a1fSTejun Heo struct pcpu_alloc_info *ai; 1338fd1e8a1fSTejun Heo size_t base_size, ai_size; 1339fd1e8a1fSTejun Heo void *ptr; 1340fd1e8a1fSTejun Heo int unit; 1341fd1e8a1fSTejun Heo 1342fd1e8a1fSTejun Heo base_size = ALIGN(sizeof(*ai) + nr_groups * sizeof(ai->groups[0]), 1343fd1e8a1fSTejun Heo __alignof__(ai->groups[0].cpu_map[0])); 1344fd1e8a1fSTejun Heo ai_size = base_size + nr_units * sizeof(ai->groups[0].cpu_map[0]); 1345fd1e8a1fSTejun Heo 1346fd1e8a1fSTejun Heo ptr = alloc_bootmem_nopanic(PFN_ALIGN(ai_size)); 1347fd1e8a1fSTejun Heo if (!ptr) 1348fd1e8a1fSTejun Heo return NULL; 1349fd1e8a1fSTejun Heo ai = ptr; 1350fd1e8a1fSTejun Heo ptr += base_size; 1351fd1e8a1fSTejun Heo 1352fd1e8a1fSTejun Heo ai->groups[0].cpu_map = ptr; 1353fd1e8a1fSTejun Heo 1354fd1e8a1fSTejun Heo for (unit = 0; unit < nr_units; unit++) 1355fd1e8a1fSTejun Heo ai->groups[0].cpu_map[unit] = NR_CPUS; 1356fd1e8a1fSTejun Heo 1357fd1e8a1fSTejun Heo ai->nr_groups = nr_groups; 1358fd1e8a1fSTejun Heo ai->__ai_size = PFN_ALIGN(ai_size); 1359fd1e8a1fSTejun Heo 1360fd1e8a1fSTejun Heo return ai; 1361fd1e8a1fSTejun Heo } 1362fd1e8a1fSTejun Heo 1363fd1e8a1fSTejun Heo /** 1364fd1e8a1fSTejun Heo * pcpu_free_alloc_info - free percpu allocation info 1365fd1e8a1fSTejun Heo * @ai: pcpu_alloc_info to free 1366fd1e8a1fSTejun Heo * 1367fd1e8a1fSTejun Heo * Free @ai which was allocated by pcpu_alloc_alloc_info(). 1368fd1e8a1fSTejun Heo */ 1369fd1e8a1fSTejun Heo void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai) 1370fd1e8a1fSTejun Heo { 1371fd1e8a1fSTejun Heo free_bootmem(__pa(ai), ai->__ai_size); 1372fd1e8a1fSTejun Heo } 1373fd1e8a1fSTejun Heo 1374fd1e8a1fSTejun Heo /** 1375fd1e8a1fSTejun Heo * pcpu_build_alloc_info - build alloc_info considering distances between CPUs 1376edcb4639STejun Heo * @reserved_size: the size of reserved percpu area in bytes 1377cafe8816STejun Heo * @dyn_size: free size for dynamic allocation in bytes, -1 for auto 1378fd1e8a1fSTejun Heo * @atom_size: allocation atom size 1379fd1e8a1fSTejun Heo * @cpu_distance_fn: callback to determine distance between cpus, optional 1380fd1e8a1fSTejun Heo * 1381fd1e8a1fSTejun Heo * This function determines grouping of units, their mappings to cpus 1382fd1e8a1fSTejun Heo * and other parameters considering needed percpu size, allocation 1383fd1e8a1fSTejun Heo * atom size and distances between CPUs. 1384fd1e8a1fSTejun Heo * 1385fd1e8a1fSTejun Heo * Groups are always mutliples of atom size and CPUs which are of 1386fd1e8a1fSTejun Heo * LOCAL_DISTANCE both ways are grouped together and share space for 1387fd1e8a1fSTejun Heo * units in the same group. The returned configuration is guaranteed 1388fd1e8a1fSTejun Heo * to have CPUs on different nodes on different groups and >=75% usage 1389fd1e8a1fSTejun Heo * of allocated virtual address space. 1390fd1e8a1fSTejun Heo * 1391fd1e8a1fSTejun Heo * RETURNS: 1392fd1e8a1fSTejun Heo * On success, pointer to the new allocation_info is returned. On 1393fd1e8a1fSTejun Heo * failure, ERR_PTR value is returned. 1394fd1e8a1fSTejun Heo */ 1395fd1e8a1fSTejun Heo struct pcpu_alloc_info * __init pcpu_build_alloc_info( 1396fd1e8a1fSTejun Heo size_t reserved_size, ssize_t dyn_size, 1397fd1e8a1fSTejun Heo size_t atom_size, 1398033e48fbSTejun Heo pcpu_fc_cpu_distance_fn_t cpu_distance_fn) 1399033e48fbSTejun Heo { 1400033e48fbSTejun Heo static int group_map[NR_CPUS] __initdata; 1401033e48fbSTejun Heo static int group_cnt[NR_CPUS] __initdata; 1402033e48fbSTejun Heo const size_t static_size = __per_cpu_end - __per_cpu_start; 1403fd1e8a1fSTejun Heo int group_cnt_max = 0, nr_groups = 1, nr_units = 0; 1404033e48fbSTejun Heo size_t size_sum, min_unit_size, alloc_size; 1405033e48fbSTejun Heo int upa, max_upa, uninitialized_var(best_upa); /* units_per_alloc */ 1406fd1e8a1fSTejun Heo int last_allocs, group, unit; 1407033e48fbSTejun Heo unsigned int cpu, tcpu; 1408fd1e8a1fSTejun Heo struct pcpu_alloc_info *ai; 1409fd1e8a1fSTejun Heo unsigned int *cpu_map; 1410033e48fbSTejun Heo 1411fb59e72eSTejun Heo /* this function may be called multiple times */ 1412fb59e72eSTejun Heo memset(group_map, 0, sizeof(group_map)); 1413fb59e72eSTejun Heo memset(group_cnt, 0, sizeof(group_map)); 1414fb59e72eSTejun Heo 1415033e48fbSTejun Heo /* 1416033e48fbSTejun Heo * Determine min_unit_size, alloc_size and max_upa such that 1417fd1e8a1fSTejun Heo * alloc_size is multiple of atom_size and is the smallest 1418033e48fbSTejun Heo * which can accomodate 4k aligned segments which are equal to 1419033e48fbSTejun Heo * or larger than min_unit_size. 1420033e48fbSTejun Heo */ 1421fd1e8a1fSTejun Heo size_sum = pcpu_calc_fc_sizes(static_size, reserved_size, &dyn_size); 1422033e48fbSTejun Heo min_unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE); 1423033e48fbSTejun Heo 1424fd1e8a1fSTejun Heo alloc_size = roundup(min_unit_size, atom_size); 1425033e48fbSTejun Heo upa = alloc_size / min_unit_size; 1426033e48fbSTejun Heo while (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK)) 1427033e48fbSTejun Heo upa--; 1428033e48fbSTejun Heo max_upa = upa; 1429033e48fbSTejun Heo 1430033e48fbSTejun Heo /* group cpus according to their proximity */ 1431033e48fbSTejun Heo for_each_possible_cpu(cpu) { 1432033e48fbSTejun Heo group = 0; 1433033e48fbSTejun Heo next_group: 1434033e48fbSTejun Heo for_each_possible_cpu(tcpu) { 1435033e48fbSTejun Heo if (cpu == tcpu) 1436033e48fbSTejun Heo break; 1437fd1e8a1fSTejun Heo if (group_map[tcpu] == group && cpu_distance_fn && 1438033e48fbSTejun Heo (cpu_distance_fn(cpu, tcpu) > LOCAL_DISTANCE || 1439033e48fbSTejun Heo cpu_distance_fn(tcpu, cpu) > LOCAL_DISTANCE)) { 1440033e48fbSTejun Heo group++; 1441fd1e8a1fSTejun Heo nr_groups = max(nr_groups, group + 1); 1442033e48fbSTejun Heo goto next_group; 1443033e48fbSTejun Heo } 1444033e48fbSTejun Heo } 1445033e48fbSTejun Heo group_map[cpu] = group; 1446033e48fbSTejun Heo group_cnt[group]++; 1447033e48fbSTejun Heo group_cnt_max = max(group_cnt_max, group_cnt[group]); 1448033e48fbSTejun Heo } 1449033e48fbSTejun Heo 1450033e48fbSTejun Heo /* 1451033e48fbSTejun Heo * Expand unit size until address space usage goes over 75% 1452033e48fbSTejun Heo * and then as much as possible without using more address 1453033e48fbSTejun Heo * space. 1454033e48fbSTejun Heo */ 1455033e48fbSTejun Heo last_allocs = INT_MAX; 1456033e48fbSTejun Heo for (upa = max_upa; upa; upa--) { 1457033e48fbSTejun Heo int allocs = 0, wasted = 0; 1458033e48fbSTejun Heo 1459033e48fbSTejun Heo if (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK)) 1460033e48fbSTejun Heo continue; 1461033e48fbSTejun Heo 1462fd1e8a1fSTejun Heo for (group = 0; group < nr_groups; group++) { 1463033e48fbSTejun Heo int this_allocs = DIV_ROUND_UP(group_cnt[group], upa); 1464033e48fbSTejun Heo allocs += this_allocs; 1465033e48fbSTejun Heo wasted += this_allocs * upa - group_cnt[group]; 1466033e48fbSTejun Heo } 1467033e48fbSTejun Heo 1468033e48fbSTejun Heo /* 1469033e48fbSTejun Heo * Don't accept if wastage is over 25%. The 1470033e48fbSTejun Heo * greater-than comparison ensures upa==1 always 1471033e48fbSTejun Heo * passes the following check. 1472033e48fbSTejun Heo */ 1473033e48fbSTejun Heo if (wasted > num_possible_cpus() / 3) 1474033e48fbSTejun Heo continue; 1475033e48fbSTejun Heo 1476033e48fbSTejun Heo /* and then don't consume more memory */ 1477033e48fbSTejun Heo if (allocs > last_allocs) 1478033e48fbSTejun Heo break; 1479033e48fbSTejun Heo last_allocs = allocs; 1480033e48fbSTejun Heo best_upa = upa; 1481033e48fbSTejun Heo } 1482fd1e8a1fSTejun Heo upa = best_upa; 1483033e48fbSTejun Heo 1484fd1e8a1fSTejun Heo /* allocate and fill alloc_info */ 1485fd1e8a1fSTejun Heo for (group = 0; group < nr_groups; group++) 1486fd1e8a1fSTejun Heo nr_units += roundup(group_cnt[group], upa); 1487fd1e8a1fSTejun Heo 1488fd1e8a1fSTejun Heo ai = pcpu_alloc_alloc_info(nr_groups, nr_units); 1489fd1e8a1fSTejun Heo if (!ai) 1490fd1e8a1fSTejun Heo return ERR_PTR(-ENOMEM); 1491fd1e8a1fSTejun Heo cpu_map = ai->groups[0].cpu_map; 1492fd1e8a1fSTejun Heo 1493fd1e8a1fSTejun Heo for (group = 0; group < nr_groups; group++) { 1494fd1e8a1fSTejun Heo ai->groups[group].cpu_map = cpu_map; 1495fd1e8a1fSTejun Heo cpu_map += roundup(group_cnt[group], upa); 1496fd1e8a1fSTejun Heo } 1497fd1e8a1fSTejun Heo 1498fd1e8a1fSTejun Heo ai->static_size = static_size; 1499fd1e8a1fSTejun Heo ai->reserved_size = reserved_size; 1500fd1e8a1fSTejun Heo ai->dyn_size = dyn_size; 1501fd1e8a1fSTejun Heo ai->unit_size = alloc_size / upa; 1502fd1e8a1fSTejun Heo ai->atom_size = atom_size; 1503fd1e8a1fSTejun Heo ai->alloc_size = alloc_size; 1504fd1e8a1fSTejun Heo 1505fd1e8a1fSTejun Heo for (group = 0, unit = 0; group_cnt[group]; group++) { 1506fd1e8a1fSTejun Heo struct pcpu_group_info *gi = &ai->groups[group]; 1507fd1e8a1fSTejun Heo 1508fd1e8a1fSTejun Heo /* 1509fd1e8a1fSTejun Heo * Initialize base_offset as if all groups are located 1510fd1e8a1fSTejun Heo * back-to-back. The caller should update this to 1511fd1e8a1fSTejun Heo * reflect actual allocation. 1512fd1e8a1fSTejun Heo */ 1513fd1e8a1fSTejun Heo gi->base_offset = unit * ai->unit_size; 1514fd1e8a1fSTejun Heo 1515033e48fbSTejun Heo for_each_possible_cpu(cpu) 1516033e48fbSTejun Heo if (group_map[cpu] == group) 1517fd1e8a1fSTejun Heo gi->cpu_map[gi->nr_units++] = cpu; 1518fd1e8a1fSTejun Heo gi->nr_units = roundup(gi->nr_units, upa); 1519fd1e8a1fSTejun Heo unit += gi->nr_units; 1520fd1e8a1fSTejun Heo } 1521fd1e8a1fSTejun Heo BUG_ON(unit != nr_units); 1522fd1e8a1fSTejun Heo 1523fd1e8a1fSTejun Heo return ai; 1524033e48fbSTejun Heo } 1525033e48fbSTejun Heo 1526fd1e8a1fSTejun Heo /** 1527fd1e8a1fSTejun Heo * pcpu_dump_alloc_info - print out information about pcpu_alloc_info 1528fd1e8a1fSTejun Heo * @lvl: loglevel 1529fd1e8a1fSTejun Heo * @ai: allocation info to dump 1530fd1e8a1fSTejun Heo * 1531fd1e8a1fSTejun Heo * Print out information about @ai using loglevel @lvl. 1532fd1e8a1fSTejun Heo */ 1533fd1e8a1fSTejun Heo static void pcpu_dump_alloc_info(const char *lvl, 1534fd1e8a1fSTejun Heo const struct pcpu_alloc_info *ai) 1535033e48fbSTejun Heo { 1536fd1e8a1fSTejun Heo int group_width = 1, cpu_width = 1, width; 1537033e48fbSTejun Heo char empty_str[] = "--------"; 1538fd1e8a1fSTejun Heo int alloc = 0, alloc_end = 0; 1539fd1e8a1fSTejun Heo int group, v; 1540fd1e8a1fSTejun Heo int upa, apl; /* units per alloc, allocs per line */ 1541033e48fbSTejun Heo 1542fd1e8a1fSTejun Heo v = ai->nr_groups; 1543033e48fbSTejun Heo while (v /= 10) 1544fd1e8a1fSTejun Heo group_width++; 1545033e48fbSTejun Heo 1546fd1e8a1fSTejun Heo v = num_possible_cpus(); 1547fd1e8a1fSTejun Heo while (v /= 10) 1548fd1e8a1fSTejun Heo cpu_width++; 1549fd1e8a1fSTejun Heo empty_str[min_t(int, cpu_width, sizeof(empty_str) - 1)] = '\0'; 1550033e48fbSTejun Heo 1551fd1e8a1fSTejun Heo upa = ai->alloc_size / ai->unit_size; 1552fd1e8a1fSTejun Heo width = upa * (cpu_width + 1) + group_width + 3; 1553fd1e8a1fSTejun Heo apl = rounddown_pow_of_two(max(60 / width, 1)); 1554033e48fbSTejun Heo 1555fd1e8a1fSTejun Heo printk("%spcpu-alloc: s%zu r%zu d%zu u%zu alloc=%zu*%zu", 1556fd1e8a1fSTejun Heo lvl, ai->static_size, ai->reserved_size, ai->dyn_size, 1557fd1e8a1fSTejun Heo ai->unit_size, ai->alloc_size / ai->atom_size, ai->atom_size); 1558fd1e8a1fSTejun Heo 1559fd1e8a1fSTejun Heo for (group = 0; group < ai->nr_groups; group++) { 1560fd1e8a1fSTejun Heo const struct pcpu_group_info *gi = &ai->groups[group]; 1561fd1e8a1fSTejun Heo int unit = 0, unit_end = 0; 1562fd1e8a1fSTejun Heo 1563fd1e8a1fSTejun Heo BUG_ON(gi->nr_units % upa); 1564fd1e8a1fSTejun Heo for (alloc_end += gi->nr_units / upa; 1565fd1e8a1fSTejun Heo alloc < alloc_end; alloc++) { 1566fd1e8a1fSTejun Heo if (!(alloc % apl)) { 1567033e48fbSTejun Heo printk("\n"); 1568fd1e8a1fSTejun Heo printk("%spcpu-alloc: ", lvl); 1569033e48fbSTejun Heo } 1570fd1e8a1fSTejun Heo printk("[%0*d] ", group_width, group); 1571fd1e8a1fSTejun Heo 1572fd1e8a1fSTejun Heo for (unit_end += upa; unit < unit_end; unit++) 1573fd1e8a1fSTejun Heo if (gi->cpu_map[unit] != NR_CPUS) 1574fd1e8a1fSTejun Heo printk("%0*d ", cpu_width, 1575fd1e8a1fSTejun Heo gi->cpu_map[unit]); 1576033e48fbSTejun Heo else 1577033e48fbSTejun Heo printk("%s ", empty_str); 1578033e48fbSTejun Heo } 1579fd1e8a1fSTejun Heo } 1580033e48fbSTejun Heo printk("\n"); 1581033e48fbSTejun Heo } 1582033e48fbSTejun Heo 1583fbf59bc9STejun Heo /** 15848d408b4bSTejun Heo * pcpu_setup_first_chunk - initialize the first percpu chunk 1585fd1e8a1fSTejun Heo * @ai: pcpu_alloc_info describing how to percpu area is shaped 158638a6be52STejun Heo * @base_addr: mapped address 1587fbf59bc9STejun Heo * 15888d408b4bSTejun Heo * Initialize the first percpu chunk which contains the kernel static 15898d408b4bSTejun Heo * perpcu area. This function is to be called from arch percpu area 159038a6be52STejun Heo * setup path. 15918d408b4bSTejun Heo * 1592fd1e8a1fSTejun Heo * @ai contains all information necessary to initialize the first 1593fd1e8a1fSTejun Heo * chunk and prime the dynamic percpu allocator. 15948d408b4bSTejun Heo * 1595fd1e8a1fSTejun Heo * @ai->static_size is the size of static percpu area. 1596fd1e8a1fSTejun Heo * 1597fd1e8a1fSTejun Heo * @ai->reserved_size, if non-zero, specifies the amount of bytes to 1598edcb4639STejun Heo * reserve after the static area in the first chunk. This reserves 1599edcb4639STejun Heo * the first chunk such that it's available only through reserved 1600edcb4639STejun Heo * percpu allocation. This is primarily used to serve module percpu 1601edcb4639STejun Heo * static areas on architectures where the addressing model has 1602edcb4639STejun Heo * limited offset range for symbol relocations to guarantee module 1603edcb4639STejun Heo * percpu symbols fall inside the relocatable range. 1604edcb4639STejun Heo * 1605fd1e8a1fSTejun Heo * @ai->dyn_size determines the number of bytes available for dynamic 1606fd1e8a1fSTejun Heo * allocation in the first chunk. The area between @ai->static_size + 1607fd1e8a1fSTejun Heo * @ai->reserved_size + @ai->dyn_size and @ai->unit_size is unused. 16086074d5b0STejun Heo * 1609fd1e8a1fSTejun Heo * @ai->unit_size specifies unit size and must be aligned to PAGE_SIZE 1610fd1e8a1fSTejun Heo * and equal to or larger than @ai->static_size + @ai->reserved_size + 1611fd1e8a1fSTejun Heo * @ai->dyn_size. 16128d408b4bSTejun Heo * 1613fd1e8a1fSTejun Heo * @ai->atom_size is the allocation atom size and used as alignment 1614fd1e8a1fSTejun Heo * for vm areas. 16158d408b4bSTejun Heo * 1616fd1e8a1fSTejun Heo * @ai->alloc_size is the allocation size and always multiple of 1617fd1e8a1fSTejun Heo * @ai->atom_size. This is larger than @ai->atom_size if 1618fd1e8a1fSTejun Heo * @ai->unit_size is larger than @ai->atom_size. 1619fd1e8a1fSTejun Heo * 1620fd1e8a1fSTejun Heo * @ai->nr_groups and @ai->groups describe virtual memory layout of 1621fd1e8a1fSTejun Heo * percpu areas. Units which should be colocated are put into the 1622fd1e8a1fSTejun Heo * same group. Dynamic VM areas will be allocated according to these 1623fd1e8a1fSTejun Heo * groupings. If @ai->nr_groups is zero, a single group containing 1624fd1e8a1fSTejun Heo * all units is assumed. 16258d408b4bSTejun Heo * 162638a6be52STejun Heo * The caller should have mapped the first chunk at @base_addr and 162738a6be52STejun Heo * copied static data to each unit. 1628fbf59bc9STejun Heo * 1629edcb4639STejun Heo * If the first chunk ends up with both reserved and dynamic areas, it 1630edcb4639STejun Heo * is served by two chunks - one to serve the core static and reserved 1631edcb4639STejun Heo * areas and the other for the dynamic area. They share the same vm 1632edcb4639STejun Heo * and page map but uses different area allocation map to stay away 1633edcb4639STejun Heo * from each other. The latter chunk is circulated in the chunk slots 1634edcb4639STejun Heo * and available for dynamic allocation like any other chunks. 1635edcb4639STejun Heo * 1636fbf59bc9STejun Heo * RETURNS: 1637fb435d52STejun Heo * 0 on success, -errno on failure. 1638fbf59bc9STejun Heo */ 1639fb435d52STejun Heo int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, 1640fd1e8a1fSTejun Heo void *base_addr) 1641fbf59bc9STejun Heo { 1642635b75fcSTejun Heo static char cpus_buf[4096] __initdata; 1643edcb4639STejun Heo static int smap[2], dmap[2]; 1644fd1e8a1fSTejun Heo size_t dyn_size = ai->dyn_size; 1645fd1e8a1fSTejun Heo size_t size_sum = ai->static_size + ai->reserved_size + dyn_size; 1646edcb4639STejun Heo struct pcpu_chunk *schunk, *dchunk = NULL; 16476563297cSTejun Heo unsigned long *group_offsets; 16486563297cSTejun Heo size_t *group_sizes; 1649fb435d52STejun Heo unsigned long *unit_off; 1650fbf59bc9STejun Heo unsigned int cpu; 1651fd1e8a1fSTejun Heo int *unit_map; 1652fd1e8a1fSTejun Heo int group, unit, i; 1653fbf59bc9STejun Heo 1654635b75fcSTejun Heo cpumask_scnprintf(cpus_buf, sizeof(cpus_buf), cpu_possible_mask); 1655635b75fcSTejun Heo 1656635b75fcSTejun Heo #define PCPU_SETUP_BUG_ON(cond) do { \ 1657635b75fcSTejun Heo if (unlikely(cond)) { \ 1658635b75fcSTejun Heo pr_emerg("PERCPU: failed to initialize, %s", #cond); \ 1659635b75fcSTejun Heo pr_emerg("PERCPU: cpu_possible_mask=%s\n", cpus_buf); \ 1660635b75fcSTejun Heo pcpu_dump_alloc_info(KERN_EMERG, ai); \ 1661635b75fcSTejun Heo BUG(); \ 1662635b75fcSTejun Heo } \ 1663635b75fcSTejun Heo } while (0) 1664635b75fcSTejun Heo 16652f39e637STejun Heo /* sanity checks */ 1666edcb4639STejun Heo BUILD_BUG_ON(ARRAY_SIZE(smap) >= PCPU_DFL_MAP_ALLOC || 1667edcb4639STejun Heo ARRAY_SIZE(dmap) >= PCPU_DFL_MAP_ALLOC); 1668635b75fcSTejun Heo PCPU_SETUP_BUG_ON(ai->nr_groups <= 0); 1669635b75fcSTejun Heo PCPU_SETUP_BUG_ON(!ai->static_size); 1670635b75fcSTejun Heo PCPU_SETUP_BUG_ON(!base_addr); 1671635b75fcSTejun Heo PCPU_SETUP_BUG_ON(ai->unit_size < size_sum); 1672635b75fcSTejun Heo PCPU_SETUP_BUG_ON(ai->unit_size & ~PAGE_MASK); 1673635b75fcSTejun Heo PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE); 16748d408b4bSTejun Heo 16756563297cSTejun Heo /* process group information and build config tables accordingly */ 16766563297cSTejun Heo group_offsets = alloc_bootmem(ai->nr_groups * sizeof(group_offsets[0])); 16776563297cSTejun Heo group_sizes = alloc_bootmem(ai->nr_groups * sizeof(group_sizes[0])); 1678fd1e8a1fSTejun Heo unit_map = alloc_bootmem(nr_cpu_ids * sizeof(unit_map[0])); 1679fb435d52STejun Heo unit_off = alloc_bootmem(nr_cpu_ids * sizeof(unit_off[0])); 16802f39e637STejun Heo 1681fd1e8a1fSTejun Heo for (cpu = 0; cpu < nr_cpu_ids; cpu++) 1682ffe0d5a5STejun Heo unit_map[cpu] = UINT_MAX; 1683fd1e8a1fSTejun Heo pcpu_first_unit_cpu = NR_CPUS; 16842f39e637STejun Heo 1685fd1e8a1fSTejun Heo for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) { 1686fd1e8a1fSTejun Heo const struct pcpu_group_info *gi = &ai->groups[group]; 16872f39e637STejun Heo 16886563297cSTejun Heo group_offsets[group] = gi->base_offset; 16896563297cSTejun Heo group_sizes[group] = gi->nr_units * ai->unit_size; 16906563297cSTejun Heo 1691fd1e8a1fSTejun Heo for (i = 0; i < gi->nr_units; i++) { 1692fd1e8a1fSTejun Heo cpu = gi->cpu_map[i]; 1693fd1e8a1fSTejun Heo if (cpu == NR_CPUS) 1694fd1e8a1fSTejun Heo continue; 1695fd1e8a1fSTejun Heo 1696635b75fcSTejun Heo PCPU_SETUP_BUG_ON(cpu > nr_cpu_ids); 1697635b75fcSTejun Heo PCPU_SETUP_BUG_ON(!cpu_possible(cpu)); 1698635b75fcSTejun Heo PCPU_SETUP_BUG_ON(unit_map[cpu] != UINT_MAX); 1699fd1e8a1fSTejun Heo 1700fd1e8a1fSTejun Heo unit_map[cpu] = unit + i; 1701fb435d52STejun Heo unit_off[cpu] = gi->base_offset + i * ai->unit_size; 1702fb435d52STejun Heo 1703fd1e8a1fSTejun Heo if (pcpu_first_unit_cpu == NR_CPUS) 17042f39e637STejun Heo pcpu_first_unit_cpu = cpu; 17052f39e637STejun Heo } 1706fd1e8a1fSTejun Heo } 17072f39e637STejun Heo pcpu_last_unit_cpu = cpu; 1708fd1e8a1fSTejun Heo pcpu_nr_units = unit; 17092f39e637STejun Heo 17102f39e637STejun Heo for_each_possible_cpu(cpu) 1711635b75fcSTejun Heo PCPU_SETUP_BUG_ON(unit_map[cpu] == UINT_MAX); 1712635b75fcSTejun Heo 1713635b75fcSTejun Heo /* we're done parsing the input, undefine BUG macro and dump config */ 1714635b75fcSTejun Heo #undef PCPU_SETUP_BUG_ON 1715635b75fcSTejun Heo pcpu_dump_alloc_info(KERN_INFO, ai); 17162f39e637STejun Heo 17176563297cSTejun Heo pcpu_nr_groups = ai->nr_groups; 17186563297cSTejun Heo pcpu_group_offsets = group_offsets; 17196563297cSTejun Heo pcpu_group_sizes = group_sizes; 1720fd1e8a1fSTejun Heo pcpu_unit_map = unit_map; 1721fb435d52STejun Heo pcpu_unit_offsets = unit_off; 17222f39e637STejun Heo 17232f39e637STejun Heo /* determine basic parameters */ 1724fd1e8a1fSTejun Heo pcpu_unit_pages = ai->unit_size >> PAGE_SHIFT; 1725d9b55eebSTejun Heo pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT; 17266563297cSTejun Heo pcpu_atom_size = ai->atom_size; 1727ce3141a2STejun Heo pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) + 1728ce3141a2STejun Heo BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long); 1729cafe8816STejun Heo 1730d9b55eebSTejun Heo /* 1731d9b55eebSTejun Heo * Allocate chunk slots. The additional last slot is for 1732d9b55eebSTejun Heo * empty chunks. 1733d9b55eebSTejun Heo */ 1734d9b55eebSTejun Heo pcpu_nr_slots = __pcpu_size_to_slot(pcpu_unit_size) + 2; 1735fbf59bc9STejun Heo pcpu_slot = alloc_bootmem(pcpu_nr_slots * sizeof(pcpu_slot[0])); 1736fbf59bc9STejun Heo for (i = 0; i < pcpu_nr_slots; i++) 1737fbf59bc9STejun Heo INIT_LIST_HEAD(&pcpu_slot[i]); 1738fbf59bc9STejun Heo 1739edcb4639STejun Heo /* 1740edcb4639STejun Heo * Initialize static chunk. If reserved_size is zero, the 1741edcb4639STejun Heo * static chunk covers static area + dynamic allocation area 1742edcb4639STejun Heo * in the first chunk. If reserved_size is not zero, it 1743edcb4639STejun Heo * covers static area + reserved area (mostly used for module 1744edcb4639STejun Heo * static percpu allocation). 1745edcb4639STejun Heo */ 17462441d15cSTejun Heo schunk = alloc_bootmem(pcpu_chunk_struct_size); 17472441d15cSTejun Heo INIT_LIST_HEAD(&schunk->list); 1748bba174f5STejun Heo schunk->base_addr = base_addr; 174961ace7faSTejun Heo schunk->map = smap; 175061ace7faSTejun Heo schunk->map_alloc = ARRAY_SIZE(smap); 175138a6be52STejun Heo schunk->immutable = true; 1752ce3141a2STejun Heo bitmap_fill(schunk->populated, pcpu_unit_pages); 1753edcb4639STejun Heo 1754fd1e8a1fSTejun Heo if (ai->reserved_size) { 1755fd1e8a1fSTejun Heo schunk->free_size = ai->reserved_size; 1756ae9e6bc9STejun Heo pcpu_reserved_chunk = schunk; 1757fd1e8a1fSTejun Heo pcpu_reserved_chunk_limit = ai->static_size + ai->reserved_size; 1758edcb4639STejun Heo } else { 17592441d15cSTejun Heo schunk->free_size = dyn_size; 1760edcb4639STejun Heo dyn_size = 0; /* dynamic area covered */ 1761edcb4639STejun Heo } 17622441d15cSTejun Heo schunk->contig_hint = schunk->free_size; 1763fbf59bc9STejun Heo 1764fd1e8a1fSTejun Heo schunk->map[schunk->map_used++] = -ai->static_size; 176561ace7faSTejun Heo if (schunk->free_size) 176661ace7faSTejun Heo schunk->map[schunk->map_used++] = schunk->free_size; 176761ace7faSTejun Heo 1768edcb4639STejun Heo /* init dynamic chunk if necessary */ 1769edcb4639STejun Heo if (dyn_size) { 1770ce3141a2STejun Heo dchunk = alloc_bootmem(pcpu_chunk_struct_size); 1771edcb4639STejun Heo INIT_LIST_HEAD(&dchunk->list); 1772bba174f5STejun Heo dchunk->base_addr = base_addr; 1773edcb4639STejun Heo dchunk->map = dmap; 1774edcb4639STejun Heo dchunk->map_alloc = ARRAY_SIZE(dmap); 177538a6be52STejun Heo dchunk->immutable = true; 1776ce3141a2STejun Heo bitmap_fill(dchunk->populated, pcpu_unit_pages); 1777edcb4639STejun Heo 1778edcb4639STejun Heo dchunk->contig_hint = dchunk->free_size = dyn_size; 1779edcb4639STejun Heo dchunk->map[dchunk->map_used++] = -pcpu_reserved_chunk_limit; 1780edcb4639STejun Heo dchunk->map[dchunk->map_used++] = dchunk->free_size; 1781edcb4639STejun Heo } 1782edcb4639STejun Heo 17832441d15cSTejun Heo /* link the first chunk in */ 1784ae9e6bc9STejun Heo pcpu_first_chunk = dchunk ?: schunk; 1785ae9e6bc9STejun Heo pcpu_chunk_relocate(pcpu_first_chunk, -1); 1786fbf59bc9STejun Heo 1787fbf59bc9STejun Heo /* we're done */ 1788bba174f5STejun Heo pcpu_base_addr = base_addr; 1789fb435d52STejun Heo return 0; 1790fbf59bc9STejun Heo } 179166c3a757STejun Heo 1792f58dc01bSTejun Heo const char *pcpu_fc_names[PCPU_FC_NR] __initdata = { 1793f58dc01bSTejun Heo [PCPU_FC_AUTO] = "auto", 1794f58dc01bSTejun Heo [PCPU_FC_EMBED] = "embed", 1795f58dc01bSTejun Heo [PCPU_FC_PAGE] = "page", 1796f58dc01bSTejun Heo }; 179766c3a757STejun Heo 1798f58dc01bSTejun Heo enum pcpu_fc pcpu_chosen_fc __initdata = PCPU_FC_AUTO; 1799f58dc01bSTejun Heo 1800f58dc01bSTejun Heo static int __init percpu_alloc_setup(char *str) 180166c3a757STejun Heo { 1802f58dc01bSTejun Heo if (0) 1803f58dc01bSTejun Heo /* nada */; 1804f58dc01bSTejun Heo #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK 1805f58dc01bSTejun Heo else if (!strcmp(str, "embed")) 1806f58dc01bSTejun Heo pcpu_chosen_fc = PCPU_FC_EMBED; 1807f58dc01bSTejun Heo #endif 1808f58dc01bSTejun Heo #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK 1809f58dc01bSTejun Heo else if (!strcmp(str, "page")) 1810f58dc01bSTejun Heo pcpu_chosen_fc = PCPU_FC_PAGE; 1811f58dc01bSTejun Heo #endif 1812f58dc01bSTejun Heo else 1813f58dc01bSTejun Heo pr_warning("PERCPU: unknown allocator %s specified\n", str); 181466c3a757STejun Heo 1815f58dc01bSTejun Heo return 0; 181666c3a757STejun Heo } 1817f58dc01bSTejun Heo early_param("percpu_alloc", percpu_alloc_setup); 181866c3a757STejun Heo 181908fc4580STejun Heo #if defined(CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK) || \ 182008fc4580STejun Heo !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) 182166c3a757STejun Heo /** 182266c3a757STejun Heo * pcpu_embed_first_chunk - embed the first percpu chunk into bootmem 182366c3a757STejun Heo * @reserved_size: the size of reserved percpu area in bytes 182466c3a757STejun Heo * @dyn_size: free size for dynamic allocation in bytes, -1 for auto 1825c8826dd5STejun Heo * @atom_size: allocation atom size 1826c8826dd5STejun Heo * @cpu_distance_fn: callback to determine distance between cpus, optional 1827c8826dd5STejun Heo * @alloc_fn: function to allocate percpu page 1828c8826dd5STejun Heo * @free_fn: funtion to free percpu page 182966c3a757STejun Heo * 183066c3a757STejun Heo * This is a helper to ease setting up embedded first percpu chunk and 183166c3a757STejun Heo * can be called where pcpu_setup_first_chunk() is expected. 183266c3a757STejun Heo * 183366c3a757STejun Heo * If this function is used to setup the first chunk, it is allocated 1834c8826dd5STejun Heo * by calling @alloc_fn and used as-is without being mapped into 1835c8826dd5STejun Heo * vmalloc area. Allocations are always whole multiples of @atom_size 1836c8826dd5STejun Heo * aligned to @atom_size. 1837c8826dd5STejun Heo * 1838c8826dd5STejun Heo * This enables the first chunk to piggy back on the linear physical 1839c8826dd5STejun Heo * mapping which often uses larger page size. Please note that this 1840c8826dd5STejun Heo * can result in very sparse cpu->unit mapping on NUMA machines thus 1841c8826dd5STejun Heo * requiring large vmalloc address space. Don't use this allocator if 1842c8826dd5STejun Heo * vmalloc space is not orders of magnitude larger than distances 1843c8826dd5STejun Heo * between node memory addresses (ie. 32bit NUMA machines). 184466c3a757STejun Heo * 184566c3a757STejun Heo * When @dyn_size is positive, dynamic area might be larger than 1846788e5abcSTejun Heo * specified to fill page alignment. When @dyn_size is auto, 1847788e5abcSTejun Heo * @dyn_size is just big enough to fill page alignment after static 1848788e5abcSTejun Heo * and reserved areas. 184966c3a757STejun Heo * 185066c3a757STejun Heo * If the needed size is smaller than the minimum or specified unit 1851c8826dd5STejun Heo * size, the leftover is returned using @free_fn. 185266c3a757STejun Heo * 185366c3a757STejun Heo * RETURNS: 1854fb435d52STejun Heo * 0 on success, -errno on failure. 185566c3a757STejun Heo */ 1856c8826dd5STejun Heo int __init pcpu_embed_first_chunk(size_t reserved_size, ssize_t dyn_size, 1857c8826dd5STejun Heo size_t atom_size, 1858c8826dd5STejun Heo pcpu_fc_cpu_distance_fn_t cpu_distance_fn, 1859c8826dd5STejun Heo pcpu_fc_alloc_fn_t alloc_fn, 1860c8826dd5STejun Heo pcpu_fc_free_fn_t free_fn) 186166c3a757STejun Heo { 1862c8826dd5STejun Heo void *base = (void *)ULONG_MAX; 1863c8826dd5STejun Heo void **areas = NULL; 1864fd1e8a1fSTejun Heo struct pcpu_alloc_info *ai; 18656ea529a2STejun Heo size_t size_sum, areas_size, max_distance; 1866c8826dd5STejun Heo int group, i, rc; 186766c3a757STejun Heo 1868c8826dd5STejun Heo ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size, 1869c8826dd5STejun Heo cpu_distance_fn); 1870fd1e8a1fSTejun Heo if (IS_ERR(ai)) 1871fd1e8a1fSTejun Heo return PTR_ERR(ai); 187266c3a757STejun Heo 1873fd1e8a1fSTejun Heo size_sum = ai->static_size + ai->reserved_size + ai->dyn_size; 1874c8826dd5STejun Heo areas_size = PFN_ALIGN(ai->nr_groups * sizeof(void *)); 187566c3a757STejun Heo 1876c8826dd5STejun Heo areas = alloc_bootmem_nopanic(areas_size); 1877c8826dd5STejun Heo if (!areas) { 1878fb435d52STejun Heo rc = -ENOMEM; 1879c8826dd5STejun Heo goto out_free; 1880fa8a7094STejun Heo } 188166c3a757STejun Heo 1882c8826dd5STejun Heo /* allocate, copy and determine base address */ 1883c8826dd5STejun Heo for (group = 0; group < ai->nr_groups; group++) { 1884c8826dd5STejun Heo struct pcpu_group_info *gi = &ai->groups[group]; 1885c8826dd5STejun Heo unsigned int cpu = NR_CPUS; 1886c8826dd5STejun Heo void *ptr; 188766c3a757STejun Heo 1888c8826dd5STejun Heo for (i = 0; i < gi->nr_units && cpu == NR_CPUS; i++) 1889c8826dd5STejun Heo cpu = gi->cpu_map[i]; 1890c8826dd5STejun Heo BUG_ON(cpu == NR_CPUS); 1891c8826dd5STejun Heo 1892c8826dd5STejun Heo /* allocate space for the whole group */ 1893c8826dd5STejun Heo ptr = alloc_fn(cpu, gi->nr_units * ai->unit_size, atom_size); 1894c8826dd5STejun Heo if (!ptr) { 1895c8826dd5STejun Heo rc = -ENOMEM; 1896c8826dd5STejun Heo goto out_free_areas; 1897c8826dd5STejun Heo } 1898c8826dd5STejun Heo areas[group] = ptr; 1899c8826dd5STejun Heo 1900c8826dd5STejun Heo base = min(ptr, base); 1901c8826dd5STejun Heo 1902c8826dd5STejun Heo for (i = 0; i < gi->nr_units; i++, ptr += ai->unit_size) { 1903c8826dd5STejun Heo if (gi->cpu_map[i] == NR_CPUS) { 1904c8826dd5STejun Heo /* unused unit, free whole */ 1905c8826dd5STejun Heo free_fn(ptr, ai->unit_size); 1906c8826dd5STejun Heo continue; 1907c8826dd5STejun Heo } 1908c8826dd5STejun Heo /* copy and return the unused part */ 1909fd1e8a1fSTejun Heo memcpy(ptr, __per_cpu_load, ai->static_size); 1910c8826dd5STejun Heo free_fn(ptr + size_sum, ai->unit_size - size_sum); 1911c8826dd5STejun Heo } 191266c3a757STejun Heo } 191366c3a757STejun Heo 1914c8826dd5STejun Heo /* base address is now known, determine group base offsets */ 19156ea529a2STejun Heo max_distance = 0; 19166ea529a2STejun Heo for (group = 0; group < ai->nr_groups; group++) { 1917c8826dd5STejun Heo ai->groups[group].base_offset = areas[group] - base; 19181a0c3298STejun Heo max_distance = max_t(size_t, max_distance, 19191a0c3298STejun Heo ai->groups[group].base_offset); 19206ea529a2STejun Heo } 19216ea529a2STejun Heo max_distance += ai->unit_size; 19226ea529a2STejun Heo 19236ea529a2STejun Heo /* warn if maximum distance is further than 75% of vmalloc space */ 19246ea529a2STejun Heo if (max_distance > (VMALLOC_END - VMALLOC_START) * 3 / 4) { 19251a0c3298STejun Heo pr_warning("PERCPU: max_distance=0x%zx too large for vmalloc " 19266ea529a2STejun Heo "space 0x%lx\n", 19276ea529a2STejun Heo max_distance, VMALLOC_END - VMALLOC_START); 19286ea529a2STejun Heo #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK 19296ea529a2STejun Heo /* and fail if we have fallback */ 19306ea529a2STejun Heo rc = -EINVAL; 19316ea529a2STejun Heo goto out_free; 19326ea529a2STejun Heo #endif 19336ea529a2STejun Heo } 1934c8826dd5STejun Heo 1935004018e2STejun Heo pr_info("PERCPU: Embedded %zu pages/cpu @%p s%zu r%zu d%zu u%zu\n", 1936fd1e8a1fSTejun Heo PFN_DOWN(size_sum), base, ai->static_size, ai->reserved_size, 1937fd1e8a1fSTejun Heo ai->dyn_size, ai->unit_size); 193866c3a757STejun Heo 1939fb435d52STejun Heo rc = pcpu_setup_first_chunk(ai, base); 1940c8826dd5STejun Heo goto out_free; 1941c8826dd5STejun Heo 1942c8826dd5STejun Heo out_free_areas: 1943c8826dd5STejun Heo for (group = 0; group < ai->nr_groups; group++) 1944c8826dd5STejun Heo free_fn(areas[group], 1945c8826dd5STejun Heo ai->groups[group].nr_units * ai->unit_size); 1946c8826dd5STejun Heo out_free: 1947fd1e8a1fSTejun Heo pcpu_free_alloc_info(ai); 1948c8826dd5STejun Heo if (areas) 1949c8826dd5STejun Heo free_bootmem(__pa(areas), areas_size); 1950fb435d52STejun Heo return rc; 1951d4b95f80STejun Heo } 195208fc4580STejun Heo #endif /* CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK || 195308fc4580STejun Heo !CONFIG_HAVE_SETUP_PER_CPU_AREA */ 1954d4b95f80STejun Heo 195508fc4580STejun Heo #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK 1956d4b95f80STejun Heo /** 195700ae4064STejun Heo * pcpu_page_first_chunk - map the first chunk using PAGE_SIZE pages 1958d4b95f80STejun Heo * @reserved_size: the size of reserved percpu area in bytes 1959d4b95f80STejun Heo * @alloc_fn: function to allocate percpu page, always called with PAGE_SIZE 1960d4b95f80STejun Heo * @free_fn: funtion to free percpu page, always called with PAGE_SIZE 1961d4b95f80STejun Heo * @populate_pte_fn: function to populate pte 1962d4b95f80STejun Heo * 196300ae4064STejun Heo * This is a helper to ease setting up page-remapped first percpu 196400ae4064STejun Heo * chunk and can be called where pcpu_setup_first_chunk() is expected. 1965d4b95f80STejun Heo * 1966d4b95f80STejun Heo * This is the basic allocator. Static percpu area is allocated 1967d4b95f80STejun Heo * page-by-page into vmalloc area. 1968d4b95f80STejun Heo * 1969d4b95f80STejun Heo * RETURNS: 1970fb435d52STejun Heo * 0 on success, -errno on failure. 1971d4b95f80STejun Heo */ 1972fb435d52STejun Heo int __init pcpu_page_first_chunk(size_t reserved_size, 1973d4b95f80STejun Heo pcpu_fc_alloc_fn_t alloc_fn, 1974d4b95f80STejun Heo pcpu_fc_free_fn_t free_fn, 1975d4b95f80STejun Heo pcpu_fc_populate_pte_fn_t populate_pte_fn) 1976d4b95f80STejun Heo { 19778f05a6a6STejun Heo static struct vm_struct vm; 1978fd1e8a1fSTejun Heo struct pcpu_alloc_info *ai; 197900ae4064STejun Heo char psize_str[16]; 1980ce3141a2STejun Heo int unit_pages; 1981d4b95f80STejun Heo size_t pages_size; 1982ce3141a2STejun Heo struct page **pages; 1983fb435d52STejun Heo int unit, i, j, rc; 1984d4b95f80STejun Heo 198500ae4064STejun Heo snprintf(psize_str, sizeof(psize_str), "%luK", PAGE_SIZE >> 10); 198600ae4064STejun Heo 1987fd1e8a1fSTejun Heo ai = pcpu_build_alloc_info(reserved_size, -1, PAGE_SIZE, NULL); 1988fd1e8a1fSTejun Heo if (IS_ERR(ai)) 1989fd1e8a1fSTejun Heo return PTR_ERR(ai); 1990fd1e8a1fSTejun Heo BUG_ON(ai->nr_groups != 1); 1991fd1e8a1fSTejun Heo BUG_ON(ai->groups[0].nr_units != num_possible_cpus()); 1992fd1e8a1fSTejun Heo 1993fd1e8a1fSTejun Heo unit_pages = ai->unit_size >> PAGE_SHIFT; 1994d4b95f80STejun Heo 1995d4b95f80STejun Heo /* unaligned allocations can't be freed, round up to page size */ 1996fd1e8a1fSTejun Heo pages_size = PFN_ALIGN(unit_pages * num_possible_cpus() * 1997fd1e8a1fSTejun Heo sizeof(pages[0])); 1998ce3141a2STejun Heo pages = alloc_bootmem(pages_size); 1999d4b95f80STejun Heo 20008f05a6a6STejun Heo /* allocate pages */ 2001d4b95f80STejun Heo j = 0; 2002fd1e8a1fSTejun Heo for (unit = 0; unit < num_possible_cpus(); unit++) 2003ce3141a2STejun Heo for (i = 0; i < unit_pages; i++) { 2004fd1e8a1fSTejun Heo unsigned int cpu = ai->groups[0].cpu_map[unit]; 2005d4b95f80STejun Heo void *ptr; 2006d4b95f80STejun Heo 20073cbc8565STejun Heo ptr = alloc_fn(cpu, PAGE_SIZE, PAGE_SIZE); 2008d4b95f80STejun Heo if (!ptr) { 200900ae4064STejun Heo pr_warning("PERCPU: failed to allocate %s page " 201000ae4064STejun Heo "for cpu%u\n", psize_str, cpu); 2011d4b95f80STejun Heo goto enomem; 2012d4b95f80STejun Heo } 2013ce3141a2STejun Heo pages[j++] = virt_to_page(ptr); 2014d4b95f80STejun Heo } 2015d4b95f80STejun Heo 20168f05a6a6STejun Heo /* allocate vm area, map the pages and copy static data */ 20178f05a6a6STejun Heo vm.flags = VM_ALLOC; 2018fd1e8a1fSTejun Heo vm.size = num_possible_cpus() * ai->unit_size; 20198f05a6a6STejun Heo vm_area_register_early(&vm, PAGE_SIZE); 20208f05a6a6STejun Heo 2021fd1e8a1fSTejun Heo for (unit = 0; unit < num_possible_cpus(); unit++) { 20221d9d3257STejun Heo unsigned long unit_addr = 2023fd1e8a1fSTejun Heo (unsigned long)vm.addr + unit * ai->unit_size; 20248f05a6a6STejun Heo 2025ce3141a2STejun Heo for (i = 0; i < unit_pages; i++) 20268f05a6a6STejun Heo populate_pte_fn(unit_addr + (i << PAGE_SHIFT)); 20278f05a6a6STejun Heo 20288f05a6a6STejun Heo /* pte already populated, the following shouldn't fail */ 2029fb435d52STejun Heo rc = __pcpu_map_pages(unit_addr, &pages[unit * unit_pages], 2030ce3141a2STejun Heo unit_pages); 2031fb435d52STejun Heo if (rc < 0) 2032fb435d52STejun Heo panic("failed to map percpu area, err=%d\n", rc); 20338f05a6a6STejun Heo 20348f05a6a6STejun Heo /* 20358f05a6a6STejun Heo * FIXME: Archs with virtual cache should flush local 20368f05a6a6STejun Heo * cache for the linear mapping here - something 20378f05a6a6STejun Heo * equivalent to flush_cache_vmap() on the local cpu. 20388f05a6a6STejun Heo * flush_cache_vmap() can't be used as most supporting 20398f05a6a6STejun Heo * data structures are not set up yet. 20408f05a6a6STejun Heo */ 20418f05a6a6STejun Heo 20428f05a6a6STejun Heo /* copy static data */ 2043fd1e8a1fSTejun Heo memcpy((void *)unit_addr, __per_cpu_load, ai->static_size); 204466c3a757STejun Heo } 204566c3a757STejun Heo 204666c3a757STejun Heo /* we're ready, commit */ 20471d9d3257STejun Heo pr_info("PERCPU: %d %s pages/cpu @%p s%zu r%zu d%zu\n", 2048fd1e8a1fSTejun Heo unit_pages, psize_str, vm.addr, ai->static_size, 2049fd1e8a1fSTejun Heo ai->reserved_size, ai->dyn_size); 205066c3a757STejun Heo 2051fb435d52STejun Heo rc = pcpu_setup_first_chunk(ai, vm.addr); 2052d4b95f80STejun Heo goto out_free_ar; 2053d4b95f80STejun Heo 2054d4b95f80STejun Heo enomem: 2055d4b95f80STejun Heo while (--j >= 0) 2056ce3141a2STejun Heo free_fn(page_address(pages[j]), PAGE_SIZE); 2057fb435d52STejun Heo rc = -ENOMEM; 2058d4b95f80STejun Heo out_free_ar: 2059ce3141a2STejun Heo free_bootmem(__pa(pages), pages_size); 2060fd1e8a1fSTejun Heo pcpu_free_alloc_info(ai); 2061fb435d52STejun Heo return rc; 206266c3a757STejun Heo } 206308fc4580STejun Heo #endif /* CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK */ 2064d4b95f80STejun Heo 20658c4bfc6eSTejun Heo /* 2066e74e3962STejun Heo * Generic percpu area setup. 2067e74e3962STejun Heo * 2068e74e3962STejun Heo * The embedding helper is used because its behavior closely resembles 2069e74e3962STejun Heo * the original non-dynamic generic percpu area setup. This is 2070e74e3962STejun Heo * important because many archs have addressing restrictions and might 2071e74e3962STejun Heo * fail if the percpu area is located far away from the previous 2072e74e3962STejun Heo * location. As an added bonus, in non-NUMA cases, embedding is 2073e74e3962STejun Heo * generally a good idea TLB-wise because percpu area can piggy back 2074e74e3962STejun Heo * on the physical linear memory mapping which uses large page 2075e74e3962STejun Heo * mappings on applicable archs. 2076e74e3962STejun Heo */ 2077e74e3962STejun Heo #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA 2078e74e3962STejun Heo unsigned long __per_cpu_offset[NR_CPUS] __read_mostly; 2079e74e3962STejun Heo EXPORT_SYMBOL(__per_cpu_offset); 2080e74e3962STejun Heo 2081c8826dd5STejun Heo static void * __init pcpu_dfl_fc_alloc(unsigned int cpu, size_t size, 2082c8826dd5STejun Heo size_t align) 2083c8826dd5STejun Heo { 2084c8826dd5STejun Heo return __alloc_bootmem_nopanic(size, align, __pa(MAX_DMA_ADDRESS)); 2085c8826dd5STejun Heo } 2086c8826dd5STejun Heo 2087c8826dd5STejun Heo static void __init pcpu_dfl_fc_free(void *ptr, size_t size) 2088c8826dd5STejun Heo { 2089c8826dd5STejun Heo free_bootmem(__pa(ptr), size); 2090c8826dd5STejun Heo } 2091c8826dd5STejun Heo 2092e74e3962STejun Heo void __init setup_per_cpu_areas(void) 2093e74e3962STejun Heo { 2094e74e3962STejun Heo unsigned long delta; 2095e74e3962STejun Heo unsigned int cpu; 2096fb435d52STejun Heo int rc; 2097e74e3962STejun Heo 2098e74e3962STejun Heo /* 2099e74e3962STejun Heo * Always reserve area for module percpu variables. That's 2100e74e3962STejun Heo * what the legacy allocator did. 2101e74e3962STejun Heo */ 2102fb435d52STejun Heo rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, 2103c8826dd5STejun Heo PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, NULL, 2104c8826dd5STejun Heo pcpu_dfl_fc_alloc, pcpu_dfl_fc_free); 2105fb435d52STejun Heo if (rc < 0) 2106e74e3962STejun Heo panic("Failed to initialized percpu areas."); 2107e74e3962STejun Heo 2108e74e3962STejun Heo delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; 2109e74e3962STejun Heo for_each_possible_cpu(cpu) 2110fb435d52STejun Heo __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu]; 2111e74e3962STejun Heo } 2112e74e3962STejun Heo #endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */ 2113