109c434b8SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 29a001fc1SVitaly Wool /* 39a001fc1SVitaly Wool * z3fold.c 49a001fc1SVitaly Wool * 59a001fc1SVitaly Wool * Author: Vitaly Wool <vitaly.wool@konsulko.com> 69a001fc1SVitaly Wool * Copyright (C) 2016, Sony Mobile Communications Inc. 79a001fc1SVitaly Wool * 89a001fc1SVitaly Wool * This implementation is based on zbud written by Seth Jennings. 99a001fc1SVitaly Wool * 109a001fc1SVitaly Wool * z3fold is an special purpose allocator for storing compressed pages. It 119a001fc1SVitaly Wool * can store up to three compressed pages per page which improves the 129a001fc1SVitaly Wool * compression ratio of zbud while retaining its main concepts (e. g. always 139a001fc1SVitaly Wool * storing an integral number of objects per page) and simplicity. 149a001fc1SVitaly Wool * It still has simple and deterministic reclaim properties that make it 159a001fc1SVitaly Wool * preferable to a higher density approach (with no requirement on integral 169a001fc1SVitaly Wool * number of object per page) when reclaim is used. 179a001fc1SVitaly Wool * 189a001fc1SVitaly Wool * As in zbud, pages are divided into "chunks". The size of the chunks is 199a001fc1SVitaly Wool * fixed at compile time and is determined by NCHUNKS_ORDER below. 209a001fc1SVitaly Wool * 219a001fc1SVitaly Wool * z3fold doesn't export any API and is meant to be used via zpool API. 229a001fc1SVitaly Wool */ 239a001fc1SVitaly Wool 249a001fc1SVitaly Wool #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 259a001fc1SVitaly Wool 269a001fc1SVitaly Wool #include <linux/atomic.h> 27d30561c5SVitaly Wool #include <linux/sched.h> 281f862989SVitaly Wool #include <linux/cpumask.h> 291f862989SVitaly Wool #include <linux/dcache.h> 309a001fc1SVitaly Wool #include <linux/list.h> 319a001fc1SVitaly Wool #include <linux/mm.h> 329a001fc1SVitaly Wool #include <linux/module.h> 331f862989SVitaly Wool #include <linux/page-flags.h> 341f862989SVitaly Wool #include <linux/migrate.h> 351f862989SVitaly Wool #include <linux/node.h> 361f862989SVitaly Wool #include <linux/compaction.h> 37d30561c5SVitaly Wool #include <linux/percpu.h> 381f862989SVitaly Wool #include <linux/mount.h> 391f862989SVitaly Wool #include <linux/fs.h> 409a001fc1SVitaly Wool #include <linux/preempt.h> 41d30561c5SVitaly Wool #include <linux/workqueue.h> 429a001fc1SVitaly Wool #include <linux/slab.h> 439a001fc1SVitaly Wool #include <linux/spinlock.h> 449a001fc1SVitaly Wool #include <linux/zpool.h> 459a001fc1SVitaly Wool 469a001fc1SVitaly Wool /* 479a001fc1SVitaly Wool * NCHUNKS_ORDER determines the internal allocation granularity, effectively 489a001fc1SVitaly Wool * adjusting internal fragmentation. It also determines the number of 499a001fc1SVitaly Wool * freelists maintained in each pool. NCHUNKS_ORDER of 6 means that the 50ede93213SVitaly Wool * allocation granularity will be in chunks of size PAGE_SIZE/64. Some chunks 51ede93213SVitaly Wool * in the beginning of an allocated page are occupied by z3fold header, so 52ede93213SVitaly Wool * NCHUNKS will be calculated to 63 (or 62 in case CONFIG_DEBUG_SPINLOCK=y), 53ede93213SVitaly Wool * which shows the max number of free chunks in z3fold page, also there will 54ede93213SVitaly Wool * be 63, or 62, respectively, freelists per pool. 559a001fc1SVitaly Wool */ 569a001fc1SVitaly Wool #define NCHUNKS_ORDER 6 579a001fc1SVitaly Wool 589a001fc1SVitaly Wool #define CHUNK_SHIFT (PAGE_SHIFT - NCHUNKS_ORDER) 599a001fc1SVitaly Wool #define CHUNK_SIZE (1 << CHUNK_SHIFT) 60ede93213SVitaly Wool #define ZHDR_SIZE_ALIGNED round_up(sizeof(struct z3fold_header), CHUNK_SIZE) 61ede93213SVitaly Wool #define ZHDR_CHUNKS (ZHDR_SIZE_ALIGNED >> CHUNK_SHIFT) 62ede93213SVitaly Wool #define TOTAL_CHUNKS (PAGE_SIZE >> CHUNK_SHIFT) 639a001fc1SVitaly Wool #define NCHUNKS ((PAGE_SIZE - ZHDR_SIZE_ALIGNED) >> CHUNK_SHIFT) 649a001fc1SVitaly Wool 65f201ebd8Szhong jiang #define BUDDY_MASK (0x3) 66ca0246bbSVitaly Wool #define BUDDY_SHIFT 2 677c2b8baaSVitaly Wool #define SLOTS_ALIGN (0x40) 687c2b8baaSVitaly Wool 697c2b8baaSVitaly Wool /***************** 707c2b8baaSVitaly Wool * Structures 717c2b8baaSVitaly Wool *****************/ 727c2b8baaSVitaly Wool struct z3fold_pool; 737c2b8baaSVitaly Wool struct z3fold_ops { 747c2b8baaSVitaly Wool int (*evict)(struct z3fold_pool *pool, unsigned long handle); 757c2b8baaSVitaly Wool }; 767c2b8baaSVitaly Wool 777c2b8baaSVitaly Wool enum buddy { 787c2b8baaSVitaly Wool HEADLESS = 0, 797c2b8baaSVitaly Wool FIRST, 807c2b8baaSVitaly Wool MIDDLE, 817c2b8baaSVitaly Wool LAST, 827c2b8baaSVitaly Wool BUDDIES_MAX = LAST 837c2b8baaSVitaly Wool }; 847c2b8baaSVitaly Wool 857c2b8baaSVitaly Wool struct z3fold_buddy_slots { 867c2b8baaSVitaly Wool /* 877c2b8baaSVitaly Wool * we are using BUDDY_MASK in handle_to_buddy etc. so there should 887c2b8baaSVitaly Wool * be enough slots to hold all possible variants 897c2b8baaSVitaly Wool */ 907c2b8baaSVitaly Wool unsigned long slot[BUDDY_MASK + 1]; 917c2b8baaSVitaly Wool unsigned long pool; /* back link + flags */ 927c2b8baaSVitaly Wool }; 937c2b8baaSVitaly Wool #define HANDLE_FLAG_MASK (0x03) 947c2b8baaSVitaly Wool 957c2b8baaSVitaly Wool /* 967c2b8baaSVitaly Wool * struct z3fold_header - z3fold page metadata occupying first chunks of each 977c2b8baaSVitaly Wool * z3fold page, except for HEADLESS pages 987c2b8baaSVitaly Wool * @buddy: links the z3fold page into the relevant list in the 997c2b8baaSVitaly Wool * pool 1007c2b8baaSVitaly Wool * @page_lock: per-page lock 1017c2b8baaSVitaly Wool * @refcount: reference count for the z3fold page 1027c2b8baaSVitaly Wool * @work: work_struct for page layout optimization 1037c2b8baaSVitaly Wool * @slots: pointer to the structure holding buddy slots 104*bb9a374dSVitaly Wool * @pool: pointer to the containing pool 1057c2b8baaSVitaly Wool * @cpu: CPU which this page "belongs" to 1067c2b8baaSVitaly Wool * @first_chunks: the size of the first buddy in chunks, 0 if free 1077c2b8baaSVitaly Wool * @middle_chunks: the size of the middle buddy in chunks, 0 if free 1087c2b8baaSVitaly Wool * @last_chunks: the size of the last buddy in chunks, 0 if free 1097c2b8baaSVitaly Wool * @first_num: the starting number (for the first handle) 1101f862989SVitaly Wool * @mapped_count: the number of objects currently mapped 1117c2b8baaSVitaly Wool */ 1127c2b8baaSVitaly Wool struct z3fold_header { 1137c2b8baaSVitaly Wool struct list_head buddy; 1147c2b8baaSVitaly Wool spinlock_t page_lock; 1157c2b8baaSVitaly Wool struct kref refcount; 1167c2b8baaSVitaly Wool struct work_struct work; 1177c2b8baaSVitaly Wool struct z3fold_buddy_slots *slots; 118*bb9a374dSVitaly Wool struct z3fold_pool *pool; 1197c2b8baaSVitaly Wool short cpu; 1207c2b8baaSVitaly Wool unsigned short first_chunks; 1217c2b8baaSVitaly Wool unsigned short middle_chunks; 1227c2b8baaSVitaly Wool unsigned short last_chunks; 1237c2b8baaSVitaly Wool unsigned short start_middle; 1247c2b8baaSVitaly Wool unsigned short first_num:2; 1251f862989SVitaly Wool unsigned short mapped_count:2; 1267c2b8baaSVitaly Wool }; 1279a001fc1SVitaly Wool 1289a001fc1SVitaly Wool /** 1299a001fc1SVitaly Wool * struct z3fold_pool - stores metadata for each z3fold pool 130d30561c5SVitaly Wool * @name: pool name 131d30561c5SVitaly Wool * @lock: protects pool unbuddied/lru lists 132d30561c5SVitaly Wool * @stale_lock: protects pool stale page list 133d30561c5SVitaly Wool * @unbuddied: per-cpu array of lists tracking z3fold pages that contain 2- 134d30561c5SVitaly Wool * buddies; the list each z3fold page is added to depends on 135d30561c5SVitaly Wool * the size of its free region. 1369a001fc1SVitaly Wool * @lru: list tracking the z3fold pages in LRU order by most recently 1379a001fc1SVitaly Wool * added buddy. 138d30561c5SVitaly Wool * @stale: list of pages marked for freeing 1399a001fc1SVitaly Wool * @pages_nr: number of z3fold pages in the pool. 1407c2b8baaSVitaly Wool * @c_handle: cache for z3fold_buddy_slots allocation 1419a001fc1SVitaly Wool * @ops: pointer to a structure of user defined operations specified at 1429a001fc1SVitaly Wool * pool creation time. 143d30561c5SVitaly Wool * @compact_wq: workqueue for page layout background optimization 144d30561c5SVitaly Wool * @release_wq: workqueue for safe page release 145d30561c5SVitaly Wool * @work: work_struct for safe page release 1461f862989SVitaly Wool * @inode: inode for z3fold pseudo filesystem 1479a001fc1SVitaly Wool * 1489a001fc1SVitaly Wool * This structure is allocated at pool creation time and maintains metadata 1499a001fc1SVitaly Wool * pertaining to a particular z3fold pool. 1509a001fc1SVitaly Wool */ 1519a001fc1SVitaly Wool struct z3fold_pool { 152d30561c5SVitaly Wool const char *name; 1539a001fc1SVitaly Wool spinlock_t lock; 154d30561c5SVitaly Wool spinlock_t stale_lock; 155d30561c5SVitaly Wool struct list_head *unbuddied; 1569a001fc1SVitaly Wool struct list_head lru; 157d30561c5SVitaly Wool struct list_head stale; 15812d59ae6SVitaly Wool atomic64_t pages_nr; 1597c2b8baaSVitaly Wool struct kmem_cache *c_handle; 1609a001fc1SVitaly Wool const struct z3fold_ops *ops; 1619a001fc1SVitaly Wool struct zpool *zpool; 1629a001fc1SVitaly Wool const struct zpool_ops *zpool_ops; 163d30561c5SVitaly Wool struct workqueue_struct *compact_wq; 164d30561c5SVitaly Wool struct workqueue_struct *release_wq; 165d30561c5SVitaly Wool struct work_struct work; 1661f862989SVitaly Wool struct inode *inode; 1679a001fc1SVitaly Wool }; 1689a001fc1SVitaly Wool 1699a001fc1SVitaly Wool /* 1709a001fc1SVitaly Wool * Internal z3fold page flags 1719a001fc1SVitaly Wool */ 1729a001fc1SVitaly Wool enum z3fold_page_flags { 1735a27aa82SVitaly Wool PAGE_HEADLESS = 0, 1749a001fc1SVitaly Wool MIDDLE_CHUNK_MAPPED, 175d30561c5SVitaly Wool NEEDS_COMPACTING, 1766098d7e1SVitaly Wool PAGE_STALE, 177ca0246bbSVitaly Wool PAGE_CLAIMED, /* by either reclaim or free */ 1789a001fc1SVitaly Wool }; 1799a001fc1SVitaly Wool 1809a001fc1SVitaly Wool /***************** 1819a001fc1SVitaly Wool * Helpers 1829a001fc1SVitaly Wool *****************/ 1839a001fc1SVitaly Wool 1849a001fc1SVitaly Wool /* Converts an allocation size in bytes to size in z3fold chunks */ 1859a001fc1SVitaly Wool static int size_to_chunks(size_t size) 1869a001fc1SVitaly Wool { 1879a001fc1SVitaly Wool return (size + CHUNK_SIZE - 1) >> CHUNK_SHIFT; 1889a001fc1SVitaly Wool } 1899a001fc1SVitaly Wool 1909a001fc1SVitaly Wool #define for_each_unbuddied_list(_iter, _begin) \ 1919a001fc1SVitaly Wool for ((_iter) = (_begin); (_iter) < NCHUNKS; (_iter)++) 1929a001fc1SVitaly Wool 193d30561c5SVitaly Wool static void compact_page_work(struct work_struct *w); 194d30561c5SVitaly Wool 195bb9f6f63SVitaly Wool static inline struct z3fold_buddy_slots *alloc_slots(struct z3fold_pool *pool, 196bb9f6f63SVitaly Wool gfp_t gfp) 1977c2b8baaSVitaly Wool { 1987c2b8baaSVitaly Wool struct z3fold_buddy_slots *slots = kmem_cache_alloc(pool->c_handle, 199bb9f6f63SVitaly Wool gfp); 2007c2b8baaSVitaly Wool 2017c2b8baaSVitaly Wool if (slots) { 2027c2b8baaSVitaly Wool memset(slots->slot, 0, sizeof(slots->slot)); 2037c2b8baaSVitaly Wool slots->pool = (unsigned long)pool; 2047c2b8baaSVitaly Wool } 2057c2b8baaSVitaly Wool 2067c2b8baaSVitaly Wool return slots; 2077c2b8baaSVitaly Wool } 2087c2b8baaSVitaly Wool 2097c2b8baaSVitaly Wool static inline struct z3fold_pool *slots_to_pool(struct z3fold_buddy_slots *s) 2107c2b8baaSVitaly Wool { 2117c2b8baaSVitaly Wool return (struct z3fold_pool *)(s->pool & ~HANDLE_FLAG_MASK); 2127c2b8baaSVitaly Wool } 2137c2b8baaSVitaly Wool 2147c2b8baaSVitaly Wool static inline struct z3fold_buddy_slots *handle_to_slots(unsigned long handle) 2157c2b8baaSVitaly Wool { 2167c2b8baaSVitaly Wool return (struct z3fold_buddy_slots *)(handle & ~(SLOTS_ALIGN - 1)); 2177c2b8baaSVitaly Wool } 2187c2b8baaSVitaly Wool 2197c2b8baaSVitaly Wool static inline void free_handle(unsigned long handle) 2207c2b8baaSVitaly Wool { 2217c2b8baaSVitaly Wool struct z3fold_buddy_slots *slots; 2227c2b8baaSVitaly Wool int i; 2237c2b8baaSVitaly Wool bool is_free; 2247c2b8baaSVitaly Wool 2257c2b8baaSVitaly Wool if (handle & (1 << PAGE_HEADLESS)) 2267c2b8baaSVitaly Wool return; 2277c2b8baaSVitaly Wool 2287c2b8baaSVitaly Wool WARN_ON(*(unsigned long *)handle == 0); 2297c2b8baaSVitaly Wool *(unsigned long *)handle = 0; 2307c2b8baaSVitaly Wool slots = handle_to_slots(handle); 2317c2b8baaSVitaly Wool is_free = true; 2327c2b8baaSVitaly Wool for (i = 0; i <= BUDDY_MASK; i++) { 2337c2b8baaSVitaly Wool if (slots->slot[i]) { 2347c2b8baaSVitaly Wool is_free = false; 2357c2b8baaSVitaly Wool break; 2367c2b8baaSVitaly Wool } 2377c2b8baaSVitaly Wool } 2387c2b8baaSVitaly Wool 2397c2b8baaSVitaly Wool if (is_free) { 2407c2b8baaSVitaly Wool struct z3fold_pool *pool = slots_to_pool(slots); 2417c2b8baaSVitaly Wool 2427c2b8baaSVitaly Wool kmem_cache_free(pool->c_handle, slots); 2437c2b8baaSVitaly Wool } 2447c2b8baaSVitaly Wool } 2457c2b8baaSVitaly Wool 2461f862989SVitaly Wool static struct dentry *z3fold_do_mount(struct file_system_type *fs_type, 2471f862989SVitaly Wool int flags, const char *dev_name, void *data) 2481f862989SVitaly Wool { 2491f862989SVitaly Wool static const struct dentry_operations ops = { 2501f862989SVitaly Wool .d_dname = simple_dname, 2511f862989SVitaly Wool }; 2521f862989SVitaly Wool 2531f862989SVitaly Wool return mount_pseudo(fs_type, "z3fold:", NULL, &ops, 0x33); 2541f862989SVitaly Wool } 2551f862989SVitaly Wool 2561f862989SVitaly Wool static struct file_system_type z3fold_fs = { 2571f862989SVitaly Wool .name = "z3fold", 2581f862989SVitaly Wool .mount = z3fold_do_mount, 2591f862989SVitaly Wool .kill_sb = kill_anon_super, 2601f862989SVitaly Wool }; 2611f862989SVitaly Wool 2621f862989SVitaly Wool static struct vfsmount *z3fold_mnt; 2631f862989SVitaly Wool static int z3fold_mount(void) 2641f862989SVitaly Wool { 2651f862989SVitaly Wool int ret = 0; 2661f862989SVitaly Wool 2671f862989SVitaly Wool z3fold_mnt = kern_mount(&z3fold_fs); 2681f862989SVitaly Wool if (IS_ERR(z3fold_mnt)) 2691f862989SVitaly Wool ret = PTR_ERR(z3fold_mnt); 2701f862989SVitaly Wool 2711f862989SVitaly Wool return ret; 2721f862989SVitaly Wool } 2731f862989SVitaly Wool 2741f862989SVitaly Wool static void z3fold_unmount(void) 2751f862989SVitaly Wool { 2761f862989SVitaly Wool kern_unmount(z3fold_mnt); 2771f862989SVitaly Wool } 2781f862989SVitaly Wool 2791f862989SVitaly Wool static const struct address_space_operations z3fold_aops; 2801f862989SVitaly Wool static int z3fold_register_migration(struct z3fold_pool *pool) 2811f862989SVitaly Wool { 2821f862989SVitaly Wool pool->inode = alloc_anon_inode(z3fold_mnt->mnt_sb); 2831f862989SVitaly Wool if (IS_ERR(pool->inode)) { 2841f862989SVitaly Wool pool->inode = NULL; 2851f862989SVitaly Wool return 1; 2861f862989SVitaly Wool } 2871f862989SVitaly Wool 2881f862989SVitaly Wool pool->inode->i_mapping->private_data = pool; 2891f862989SVitaly Wool pool->inode->i_mapping->a_ops = &z3fold_aops; 2901f862989SVitaly Wool return 0; 2911f862989SVitaly Wool } 2921f862989SVitaly Wool 2931f862989SVitaly Wool static void z3fold_unregister_migration(struct z3fold_pool *pool) 2941f862989SVitaly Wool { 2951f862989SVitaly Wool if (pool->inode) 2961f862989SVitaly Wool iput(pool->inode); 2971f862989SVitaly Wool } 2981f862989SVitaly Wool 2999a001fc1SVitaly Wool /* Initializes the z3fold header of a newly allocated z3fold page */ 300d30561c5SVitaly Wool static struct z3fold_header *init_z3fold_page(struct page *page, 301bb9f6f63SVitaly Wool struct z3fold_pool *pool, gfp_t gfp) 3029a001fc1SVitaly Wool { 3039a001fc1SVitaly Wool struct z3fold_header *zhdr = page_address(page); 304bb9f6f63SVitaly Wool struct z3fold_buddy_slots *slots = alloc_slots(pool, gfp); 3057c2b8baaSVitaly Wool 3067c2b8baaSVitaly Wool if (!slots) 3077c2b8baaSVitaly Wool return NULL; 3089a001fc1SVitaly Wool 3099a001fc1SVitaly Wool INIT_LIST_HEAD(&page->lru); 3109a001fc1SVitaly Wool clear_bit(PAGE_HEADLESS, &page->private); 3119a001fc1SVitaly Wool clear_bit(MIDDLE_CHUNK_MAPPED, &page->private); 312d30561c5SVitaly Wool clear_bit(NEEDS_COMPACTING, &page->private); 313d30561c5SVitaly Wool clear_bit(PAGE_STALE, &page->private); 314ca0246bbSVitaly Wool clear_bit(PAGE_CLAIMED, &page->private); 3159a001fc1SVitaly Wool 3162f1e5e4dSVitaly Wool spin_lock_init(&zhdr->page_lock); 3175a27aa82SVitaly Wool kref_init(&zhdr->refcount); 3189a001fc1SVitaly Wool zhdr->first_chunks = 0; 3199a001fc1SVitaly Wool zhdr->middle_chunks = 0; 3209a001fc1SVitaly Wool zhdr->last_chunks = 0; 3219a001fc1SVitaly Wool zhdr->first_num = 0; 3229a001fc1SVitaly Wool zhdr->start_middle = 0; 323d30561c5SVitaly Wool zhdr->cpu = -1; 3247c2b8baaSVitaly Wool zhdr->slots = slots; 325*bb9a374dSVitaly Wool zhdr->pool = pool; 3269a001fc1SVitaly Wool INIT_LIST_HEAD(&zhdr->buddy); 327d30561c5SVitaly Wool INIT_WORK(&zhdr->work, compact_page_work); 3289a001fc1SVitaly Wool return zhdr; 3299a001fc1SVitaly Wool } 3309a001fc1SVitaly Wool 3319a001fc1SVitaly Wool /* Resets the struct page fields and frees the page */ 3321f862989SVitaly Wool static void free_z3fold_page(struct page *page, bool headless) 3339a001fc1SVitaly Wool { 3341f862989SVitaly Wool if (!headless) { 3351f862989SVitaly Wool lock_page(page); 3361f862989SVitaly Wool __ClearPageMovable(page); 3371f862989SVitaly Wool unlock_page(page); 3381f862989SVitaly Wool } 3391f862989SVitaly Wool ClearPagePrivate(page); 3405a27aa82SVitaly Wool __free_page(page); 3415a27aa82SVitaly Wool } 3425a27aa82SVitaly Wool 3432f1e5e4dSVitaly Wool /* Lock a z3fold page */ 3442f1e5e4dSVitaly Wool static inline void z3fold_page_lock(struct z3fold_header *zhdr) 3452f1e5e4dSVitaly Wool { 3462f1e5e4dSVitaly Wool spin_lock(&zhdr->page_lock); 3472f1e5e4dSVitaly Wool } 3482f1e5e4dSVitaly Wool 34976e32a2aSVitaly Wool /* Try to lock a z3fold page */ 35076e32a2aSVitaly Wool static inline int z3fold_page_trylock(struct z3fold_header *zhdr) 35176e32a2aSVitaly Wool { 35276e32a2aSVitaly Wool return spin_trylock(&zhdr->page_lock); 35376e32a2aSVitaly Wool } 35476e32a2aSVitaly Wool 3552f1e5e4dSVitaly Wool /* Unlock a z3fold page */ 3562f1e5e4dSVitaly Wool static inline void z3fold_page_unlock(struct z3fold_header *zhdr) 3572f1e5e4dSVitaly Wool { 3582f1e5e4dSVitaly Wool spin_unlock(&zhdr->page_lock); 3592f1e5e4dSVitaly Wool } 3602f1e5e4dSVitaly Wool 3617c2b8baaSVitaly Wool /* Helper function to build the index */ 3627c2b8baaSVitaly Wool static inline int __idx(struct z3fold_header *zhdr, enum buddy bud) 3637c2b8baaSVitaly Wool { 3647c2b8baaSVitaly Wool return (bud + zhdr->first_num) & BUDDY_MASK; 3657c2b8baaSVitaly Wool } 3667c2b8baaSVitaly Wool 3679a001fc1SVitaly Wool /* 3689a001fc1SVitaly Wool * Encodes the handle of a particular buddy within a z3fold page 3699a001fc1SVitaly Wool * Pool lock should be held as this function accesses first_num 3709a001fc1SVitaly Wool */ 3719a001fc1SVitaly Wool static unsigned long encode_handle(struct z3fold_header *zhdr, enum buddy bud) 3729a001fc1SVitaly Wool { 3737c2b8baaSVitaly Wool struct z3fold_buddy_slots *slots; 3747c2b8baaSVitaly Wool unsigned long h = (unsigned long)zhdr; 3757c2b8baaSVitaly Wool int idx = 0; 3769a001fc1SVitaly Wool 3777c2b8baaSVitaly Wool /* 3787c2b8baaSVitaly Wool * For a headless page, its handle is its pointer with the extra 3797c2b8baaSVitaly Wool * PAGE_HEADLESS bit set 3807c2b8baaSVitaly Wool */ 3817c2b8baaSVitaly Wool if (bud == HEADLESS) 3827c2b8baaSVitaly Wool return h | (1 << PAGE_HEADLESS); 3837c2b8baaSVitaly Wool 3847c2b8baaSVitaly Wool /* otherwise, return pointer to encoded handle */ 3857c2b8baaSVitaly Wool idx = __idx(zhdr, bud); 3867c2b8baaSVitaly Wool h += idx; 387ca0246bbSVitaly Wool if (bud == LAST) 3887c2b8baaSVitaly Wool h |= (zhdr->last_chunks << BUDDY_SHIFT); 3897c2b8baaSVitaly Wool 3907c2b8baaSVitaly Wool slots = zhdr->slots; 3917c2b8baaSVitaly Wool slots->slot[idx] = h; 3927c2b8baaSVitaly Wool return (unsigned long)&slots->slot[idx]; 3939a001fc1SVitaly Wool } 3949a001fc1SVitaly Wool 3959a001fc1SVitaly Wool /* Returns the z3fold page where a given handle is stored */ 3961f862989SVitaly Wool static inline struct z3fold_header *handle_to_z3fold_header(unsigned long h) 3979a001fc1SVitaly Wool { 3981f862989SVitaly Wool unsigned long addr = h; 3997c2b8baaSVitaly Wool 4007c2b8baaSVitaly Wool if (!(addr & (1 << PAGE_HEADLESS))) 4011f862989SVitaly Wool addr = *(unsigned long *)h; 4027c2b8baaSVitaly Wool 4037c2b8baaSVitaly Wool return (struct z3fold_header *)(addr & PAGE_MASK); 4049a001fc1SVitaly Wool } 4059a001fc1SVitaly Wool 406ca0246bbSVitaly Wool /* only for LAST bud, returns zero otherwise */ 407ca0246bbSVitaly Wool static unsigned short handle_to_chunks(unsigned long handle) 408ca0246bbSVitaly Wool { 4097c2b8baaSVitaly Wool unsigned long addr = *(unsigned long *)handle; 4107c2b8baaSVitaly Wool 4117c2b8baaSVitaly Wool return (addr & ~PAGE_MASK) >> BUDDY_SHIFT; 412ca0246bbSVitaly Wool } 413ca0246bbSVitaly Wool 414f201ebd8Szhong jiang /* 415f201ebd8Szhong jiang * (handle & BUDDY_MASK) < zhdr->first_num is possible in encode_handle 416f201ebd8Szhong jiang * but that doesn't matter. because the masking will result in the 417f201ebd8Szhong jiang * correct buddy number. 418f201ebd8Szhong jiang */ 4199a001fc1SVitaly Wool static enum buddy handle_to_buddy(unsigned long handle) 4209a001fc1SVitaly Wool { 4217c2b8baaSVitaly Wool struct z3fold_header *zhdr; 4227c2b8baaSVitaly Wool unsigned long addr; 4237c2b8baaSVitaly Wool 4247c2b8baaSVitaly Wool WARN_ON(handle & (1 << PAGE_HEADLESS)); 4257c2b8baaSVitaly Wool addr = *(unsigned long *)handle; 4267c2b8baaSVitaly Wool zhdr = (struct z3fold_header *)(addr & PAGE_MASK); 4277c2b8baaSVitaly Wool return (addr - zhdr->first_num) & BUDDY_MASK; 4289a001fc1SVitaly Wool } 4299a001fc1SVitaly Wool 4309050cce1SVitaly Wool static inline struct z3fold_pool *zhdr_to_pool(struct z3fold_header *zhdr) 4319050cce1SVitaly Wool { 432*bb9a374dSVitaly Wool return zhdr->pool; 4339050cce1SVitaly Wool } 4349050cce1SVitaly Wool 435d30561c5SVitaly Wool static void __release_z3fold_page(struct z3fold_header *zhdr, bool locked) 436d30561c5SVitaly Wool { 437d30561c5SVitaly Wool struct page *page = virt_to_page(zhdr); 4389050cce1SVitaly Wool struct z3fold_pool *pool = zhdr_to_pool(zhdr); 439d30561c5SVitaly Wool 440d30561c5SVitaly Wool WARN_ON(!list_empty(&zhdr->buddy)); 441d30561c5SVitaly Wool set_bit(PAGE_STALE, &page->private); 44235529357SVitaly Wool clear_bit(NEEDS_COMPACTING, &page->private); 443d30561c5SVitaly Wool spin_lock(&pool->lock); 444d30561c5SVitaly Wool if (!list_empty(&page->lru)) 4451f862989SVitaly Wool list_del_init(&page->lru); 446d30561c5SVitaly Wool spin_unlock(&pool->lock); 447d30561c5SVitaly Wool if (locked) 448d30561c5SVitaly Wool z3fold_page_unlock(zhdr); 449d30561c5SVitaly Wool spin_lock(&pool->stale_lock); 450d30561c5SVitaly Wool list_add(&zhdr->buddy, &pool->stale); 451d30561c5SVitaly Wool queue_work(pool->release_wq, &pool->work); 452d30561c5SVitaly Wool spin_unlock(&pool->stale_lock); 453d30561c5SVitaly Wool } 454d30561c5SVitaly Wool 455d30561c5SVitaly Wool static void __attribute__((__unused__)) 456d30561c5SVitaly Wool release_z3fold_page(struct kref *ref) 457d30561c5SVitaly Wool { 458d30561c5SVitaly Wool struct z3fold_header *zhdr = container_of(ref, struct z3fold_header, 459d30561c5SVitaly Wool refcount); 460d30561c5SVitaly Wool __release_z3fold_page(zhdr, false); 461d30561c5SVitaly Wool } 462d30561c5SVitaly Wool 463d30561c5SVitaly Wool static void release_z3fold_page_locked(struct kref *ref) 464d30561c5SVitaly Wool { 465d30561c5SVitaly Wool struct z3fold_header *zhdr = container_of(ref, struct z3fold_header, 466d30561c5SVitaly Wool refcount); 467d30561c5SVitaly Wool WARN_ON(z3fold_page_trylock(zhdr)); 468d30561c5SVitaly Wool __release_z3fold_page(zhdr, true); 469d30561c5SVitaly Wool } 470d30561c5SVitaly Wool 471d30561c5SVitaly Wool static void release_z3fold_page_locked_list(struct kref *ref) 472d30561c5SVitaly Wool { 473d30561c5SVitaly Wool struct z3fold_header *zhdr = container_of(ref, struct z3fold_header, 474d30561c5SVitaly Wool refcount); 4759050cce1SVitaly Wool struct z3fold_pool *pool = zhdr_to_pool(zhdr); 4769050cce1SVitaly Wool spin_lock(&pool->lock); 477d30561c5SVitaly Wool list_del_init(&zhdr->buddy); 4789050cce1SVitaly Wool spin_unlock(&pool->lock); 479d30561c5SVitaly Wool 480d30561c5SVitaly Wool WARN_ON(z3fold_page_trylock(zhdr)); 481d30561c5SVitaly Wool __release_z3fold_page(zhdr, true); 482d30561c5SVitaly Wool } 483d30561c5SVitaly Wool 484d30561c5SVitaly Wool static void free_pages_work(struct work_struct *w) 485d30561c5SVitaly Wool { 486d30561c5SVitaly Wool struct z3fold_pool *pool = container_of(w, struct z3fold_pool, work); 487d30561c5SVitaly Wool 488d30561c5SVitaly Wool spin_lock(&pool->stale_lock); 489d30561c5SVitaly Wool while (!list_empty(&pool->stale)) { 490d30561c5SVitaly Wool struct z3fold_header *zhdr = list_first_entry(&pool->stale, 491d30561c5SVitaly Wool struct z3fold_header, buddy); 492d30561c5SVitaly Wool struct page *page = virt_to_page(zhdr); 493d30561c5SVitaly Wool 494d30561c5SVitaly Wool list_del(&zhdr->buddy); 495d30561c5SVitaly Wool if (WARN_ON(!test_bit(PAGE_STALE, &page->private))) 496d30561c5SVitaly Wool continue; 497d30561c5SVitaly Wool spin_unlock(&pool->stale_lock); 498d30561c5SVitaly Wool cancel_work_sync(&zhdr->work); 4991f862989SVitaly Wool free_z3fold_page(page, false); 500d30561c5SVitaly Wool cond_resched(); 501d30561c5SVitaly Wool spin_lock(&pool->stale_lock); 502d30561c5SVitaly Wool } 503d30561c5SVitaly Wool spin_unlock(&pool->stale_lock); 504d30561c5SVitaly Wool } 505d30561c5SVitaly Wool 5069a001fc1SVitaly Wool /* 5079a001fc1SVitaly Wool * Returns the number of free chunks in a z3fold page. 5089a001fc1SVitaly Wool * NB: can't be used with HEADLESS pages. 5099a001fc1SVitaly Wool */ 5109a001fc1SVitaly Wool static int num_free_chunks(struct z3fold_header *zhdr) 5119a001fc1SVitaly Wool { 5129a001fc1SVitaly Wool int nfree; 5139a001fc1SVitaly Wool /* 5149a001fc1SVitaly Wool * If there is a middle object, pick up the bigger free space 5159a001fc1SVitaly Wool * either before or after it. Otherwise just subtract the number 5169a001fc1SVitaly Wool * of chunks occupied by the first and the last objects. 5179a001fc1SVitaly Wool */ 5189a001fc1SVitaly Wool if (zhdr->middle_chunks != 0) { 5199a001fc1SVitaly Wool int nfree_before = zhdr->first_chunks ? 520ede93213SVitaly Wool 0 : zhdr->start_middle - ZHDR_CHUNKS; 5219a001fc1SVitaly Wool int nfree_after = zhdr->last_chunks ? 522ede93213SVitaly Wool 0 : TOTAL_CHUNKS - 523ede93213SVitaly Wool (zhdr->start_middle + zhdr->middle_chunks); 5249a001fc1SVitaly Wool nfree = max(nfree_before, nfree_after); 5259a001fc1SVitaly Wool } else 5269a001fc1SVitaly Wool nfree = NCHUNKS - zhdr->first_chunks - zhdr->last_chunks; 5279a001fc1SVitaly Wool return nfree; 5289a001fc1SVitaly Wool } 5299a001fc1SVitaly Wool 5309050cce1SVitaly Wool /* Add to the appropriate unbuddied list */ 5319050cce1SVitaly Wool static inline void add_to_unbuddied(struct z3fold_pool *pool, 5329050cce1SVitaly Wool struct z3fold_header *zhdr) 5339050cce1SVitaly Wool { 5349050cce1SVitaly Wool if (zhdr->first_chunks == 0 || zhdr->last_chunks == 0 || 5359050cce1SVitaly Wool zhdr->middle_chunks == 0) { 5369050cce1SVitaly Wool struct list_head *unbuddied = get_cpu_ptr(pool->unbuddied); 5379050cce1SVitaly Wool 5389050cce1SVitaly Wool int freechunks = num_free_chunks(zhdr); 5399050cce1SVitaly Wool spin_lock(&pool->lock); 5409050cce1SVitaly Wool list_add(&zhdr->buddy, &unbuddied[freechunks]); 5419050cce1SVitaly Wool spin_unlock(&pool->lock); 5429050cce1SVitaly Wool zhdr->cpu = smp_processor_id(); 5439050cce1SVitaly Wool put_cpu_ptr(pool->unbuddied); 5449050cce1SVitaly Wool } 5459050cce1SVitaly Wool } 5469050cce1SVitaly Wool 547ede93213SVitaly Wool static inline void *mchunk_memmove(struct z3fold_header *zhdr, 548ede93213SVitaly Wool unsigned short dst_chunk) 549ede93213SVitaly Wool { 550ede93213SVitaly Wool void *beg = zhdr; 551ede93213SVitaly Wool return memmove(beg + (dst_chunk << CHUNK_SHIFT), 552ede93213SVitaly Wool beg + (zhdr->start_middle << CHUNK_SHIFT), 553ede93213SVitaly Wool zhdr->middle_chunks << CHUNK_SHIFT); 554ede93213SVitaly Wool } 555ede93213SVitaly Wool 5561b096e5aSVitaly Wool #define BIG_CHUNK_GAP 3 5579a001fc1SVitaly Wool /* Has to be called with lock held */ 5589a001fc1SVitaly Wool static int z3fold_compact_page(struct z3fold_header *zhdr) 5599a001fc1SVitaly Wool { 5609a001fc1SVitaly Wool struct page *page = virt_to_page(zhdr); 5619a001fc1SVitaly Wool 562ede93213SVitaly Wool if (test_bit(MIDDLE_CHUNK_MAPPED, &page->private)) 563ede93213SVitaly Wool return 0; /* can't move middle chunk, it's used */ 5649a001fc1SVitaly Wool 5651f862989SVitaly Wool if (unlikely(PageIsolated(page))) 5661f862989SVitaly Wool return 0; 5671f862989SVitaly Wool 568ede93213SVitaly Wool if (zhdr->middle_chunks == 0) 569ede93213SVitaly Wool return 0; /* nothing to compact */ 570ede93213SVitaly Wool 571ede93213SVitaly Wool if (zhdr->first_chunks == 0 && zhdr->last_chunks == 0) { 572ede93213SVitaly Wool /* move to the beginning */ 573ede93213SVitaly Wool mchunk_memmove(zhdr, ZHDR_CHUNKS); 5749a001fc1SVitaly Wool zhdr->first_chunks = zhdr->middle_chunks; 5759a001fc1SVitaly Wool zhdr->middle_chunks = 0; 5769a001fc1SVitaly Wool zhdr->start_middle = 0; 5779a001fc1SVitaly Wool zhdr->first_num++; 578ede93213SVitaly Wool return 1; 5799a001fc1SVitaly Wool } 5809a001fc1SVitaly Wool 5811b096e5aSVitaly Wool /* 5821b096e5aSVitaly Wool * moving data is expensive, so let's only do that if 5831b096e5aSVitaly Wool * there's substantial gain (at least BIG_CHUNK_GAP chunks) 5841b096e5aSVitaly Wool */ 5851b096e5aSVitaly Wool if (zhdr->first_chunks != 0 && zhdr->last_chunks == 0 && 5861b096e5aSVitaly Wool zhdr->start_middle - (zhdr->first_chunks + ZHDR_CHUNKS) >= 5871b096e5aSVitaly Wool BIG_CHUNK_GAP) { 5881b096e5aSVitaly Wool mchunk_memmove(zhdr, zhdr->first_chunks + ZHDR_CHUNKS); 5891b096e5aSVitaly Wool zhdr->start_middle = zhdr->first_chunks + ZHDR_CHUNKS; 5901b096e5aSVitaly Wool return 1; 5911b096e5aSVitaly Wool } else if (zhdr->last_chunks != 0 && zhdr->first_chunks == 0 && 5921b096e5aSVitaly Wool TOTAL_CHUNKS - (zhdr->last_chunks + zhdr->start_middle 5931b096e5aSVitaly Wool + zhdr->middle_chunks) >= 5941b096e5aSVitaly Wool BIG_CHUNK_GAP) { 5951b096e5aSVitaly Wool unsigned short new_start = TOTAL_CHUNKS - zhdr->last_chunks - 5961b096e5aSVitaly Wool zhdr->middle_chunks; 5971b096e5aSVitaly Wool mchunk_memmove(zhdr, new_start); 5981b096e5aSVitaly Wool zhdr->start_middle = new_start; 5991b096e5aSVitaly Wool return 1; 6001b096e5aSVitaly Wool } 6011b096e5aSVitaly Wool 6021b096e5aSVitaly Wool return 0; 6031b096e5aSVitaly Wool } 6041b096e5aSVitaly Wool 605d30561c5SVitaly Wool static void do_compact_page(struct z3fold_header *zhdr, bool locked) 606d30561c5SVitaly Wool { 6079050cce1SVitaly Wool struct z3fold_pool *pool = zhdr_to_pool(zhdr); 608d30561c5SVitaly Wool struct page *page; 609d30561c5SVitaly Wool 610d30561c5SVitaly Wool page = virt_to_page(zhdr); 611d30561c5SVitaly Wool if (locked) 612d30561c5SVitaly Wool WARN_ON(z3fold_page_trylock(zhdr)); 613d30561c5SVitaly Wool else 614d30561c5SVitaly Wool z3fold_page_lock(zhdr); 6155d03a661SVitaly Wool if (WARN_ON(!test_and_clear_bit(NEEDS_COMPACTING, &page->private))) { 616d30561c5SVitaly Wool z3fold_page_unlock(zhdr); 617d30561c5SVitaly Wool return; 618d30561c5SVitaly Wool } 619d30561c5SVitaly Wool spin_lock(&pool->lock); 620d30561c5SVitaly Wool list_del_init(&zhdr->buddy); 621d30561c5SVitaly Wool spin_unlock(&pool->lock); 622d30561c5SVitaly Wool 6235d03a661SVitaly Wool if (kref_put(&zhdr->refcount, release_z3fold_page_locked)) { 6245d03a661SVitaly Wool atomic64_dec(&pool->pages_nr); 6255d03a661SVitaly Wool return; 6265d03a661SVitaly Wool } 6275d03a661SVitaly Wool 6281f862989SVitaly Wool if (unlikely(PageIsolated(page) || 6291f862989SVitaly Wool test_bit(PAGE_STALE, &page->private))) { 6301f862989SVitaly Wool z3fold_page_unlock(zhdr); 6311f862989SVitaly Wool return; 6321f862989SVitaly Wool } 6331f862989SVitaly Wool 634d30561c5SVitaly Wool z3fold_compact_page(zhdr); 6359050cce1SVitaly Wool add_to_unbuddied(pool, zhdr); 636d30561c5SVitaly Wool z3fold_page_unlock(zhdr); 637d30561c5SVitaly Wool } 638d30561c5SVitaly Wool 639d30561c5SVitaly Wool static void compact_page_work(struct work_struct *w) 640d30561c5SVitaly Wool { 641d30561c5SVitaly Wool struct z3fold_header *zhdr = container_of(w, struct z3fold_header, 642d30561c5SVitaly Wool work); 643d30561c5SVitaly Wool 644d30561c5SVitaly Wool do_compact_page(zhdr, false); 645d30561c5SVitaly Wool } 646d30561c5SVitaly Wool 6479050cce1SVitaly Wool /* returns _locked_ z3fold page header or NULL */ 6489050cce1SVitaly Wool static inline struct z3fold_header *__z3fold_alloc(struct z3fold_pool *pool, 6499050cce1SVitaly Wool size_t size, bool can_sleep) 6509050cce1SVitaly Wool { 6519050cce1SVitaly Wool struct z3fold_header *zhdr = NULL; 6529050cce1SVitaly Wool struct page *page; 6539050cce1SVitaly Wool struct list_head *unbuddied; 6549050cce1SVitaly Wool int chunks = size_to_chunks(size), i; 6559050cce1SVitaly Wool 6569050cce1SVitaly Wool lookup: 6579050cce1SVitaly Wool /* First, try to find an unbuddied z3fold page. */ 6589050cce1SVitaly Wool unbuddied = get_cpu_ptr(pool->unbuddied); 6599050cce1SVitaly Wool for_each_unbuddied_list(i, chunks) { 6609050cce1SVitaly Wool struct list_head *l = &unbuddied[i]; 6619050cce1SVitaly Wool 6629050cce1SVitaly Wool zhdr = list_first_entry_or_null(READ_ONCE(l), 6639050cce1SVitaly Wool struct z3fold_header, buddy); 6649050cce1SVitaly Wool 6659050cce1SVitaly Wool if (!zhdr) 6669050cce1SVitaly Wool continue; 6679050cce1SVitaly Wool 6689050cce1SVitaly Wool /* Re-check under lock. */ 6699050cce1SVitaly Wool spin_lock(&pool->lock); 6709050cce1SVitaly Wool l = &unbuddied[i]; 6719050cce1SVitaly Wool if (unlikely(zhdr != list_first_entry(READ_ONCE(l), 6729050cce1SVitaly Wool struct z3fold_header, buddy)) || 6739050cce1SVitaly Wool !z3fold_page_trylock(zhdr)) { 6749050cce1SVitaly Wool spin_unlock(&pool->lock); 6759050cce1SVitaly Wool zhdr = NULL; 6769050cce1SVitaly Wool put_cpu_ptr(pool->unbuddied); 6779050cce1SVitaly Wool if (can_sleep) 6789050cce1SVitaly Wool cond_resched(); 6799050cce1SVitaly Wool goto lookup; 6809050cce1SVitaly Wool } 6819050cce1SVitaly Wool list_del_init(&zhdr->buddy); 6829050cce1SVitaly Wool zhdr->cpu = -1; 6839050cce1SVitaly Wool spin_unlock(&pool->lock); 6849050cce1SVitaly Wool 6859050cce1SVitaly Wool page = virt_to_page(zhdr); 6869050cce1SVitaly Wool if (test_bit(NEEDS_COMPACTING, &page->private)) { 6879050cce1SVitaly Wool z3fold_page_unlock(zhdr); 6889050cce1SVitaly Wool zhdr = NULL; 6899050cce1SVitaly Wool put_cpu_ptr(pool->unbuddied); 6909050cce1SVitaly Wool if (can_sleep) 6919050cce1SVitaly Wool cond_resched(); 6929050cce1SVitaly Wool goto lookup; 6939050cce1SVitaly Wool } 6949050cce1SVitaly Wool 6959050cce1SVitaly Wool /* 6969050cce1SVitaly Wool * this page could not be removed from its unbuddied 6979050cce1SVitaly Wool * list while pool lock was held, and then we've taken 6989050cce1SVitaly Wool * page lock so kref_put could not be called before 6999050cce1SVitaly Wool * we got here, so it's safe to just call kref_get() 7009050cce1SVitaly Wool */ 7019050cce1SVitaly Wool kref_get(&zhdr->refcount); 7029050cce1SVitaly Wool break; 7039050cce1SVitaly Wool } 7049050cce1SVitaly Wool put_cpu_ptr(pool->unbuddied); 7059050cce1SVitaly Wool 706351618b2SVitaly Wool if (!zhdr) { 707351618b2SVitaly Wool int cpu; 708351618b2SVitaly Wool 709351618b2SVitaly Wool /* look for _exact_ match on other cpus' lists */ 710351618b2SVitaly Wool for_each_online_cpu(cpu) { 711351618b2SVitaly Wool struct list_head *l; 712351618b2SVitaly Wool 713351618b2SVitaly Wool unbuddied = per_cpu_ptr(pool->unbuddied, cpu); 714351618b2SVitaly Wool spin_lock(&pool->lock); 715351618b2SVitaly Wool l = &unbuddied[chunks]; 716351618b2SVitaly Wool 717351618b2SVitaly Wool zhdr = list_first_entry_or_null(READ_ONCE(l), 718351618b2SVitaly Wool struct z3fold_header, buddy); 719351618b2SVitaly Wool 720351618b2SVitaly Wool if (!zhdr || !z3fold_page_trylock(zhdr)) { 721351618b2SVitaly Wool spin_unlock(&pool->lock); 722351618b2SVitaly Wool zhdr = NULL; 723351618b2SVitaly Wool continue; 724351618b2SVitaly Wool } 725351618b2SVitaly Wool list_del_init(&zhdr->buddy); 726351618b2SVitaly Wool zhdr->cpu = -1; 727351618b2SVitaly Wool spin_unlock(&pool->lock); 728351618b2SVitaly Wool 729351618b2SVitaly Wool page = virt_to_page(zhdr); 730351618b2SVitaly Wool if (test_bit(NEEDS_COMPACTING, &page->private)) { 731351618b2SVitaly Wool z3fold_page_unlock(zhdr); 732351618b2SVitaly Wool zhdr = NULL; 733351618b2SVitaly Wool if (can_sleep) 734351618b2SVitaly Wool cond_resched(); 735351618b2SVitaly Wool continue; 736351618b2SVitaly Wool } 737351618b2SVitaly Wool kref_get(&zhdr->refcount); 738351618b2SVitaly Wool break; 739351618b2SVitaly Wool } 740351618b2SVitaly Wool } 741351618b2SVitaly Wool 7429050cce1SVitaly Wool return zhdr; 7439050cce1SVitaly Wool } 744d30561c5SVitaly Wool 745d30561c5SVitaly Wool /* 746d30561c5SVitaly Wool * API Functions 747d30561c5SVitaly Wool */ 748d30561c5SVitaly Wool 749d30561c5SVitaly Wool /** 750d30561c5SVitaly Wool * z3fold_create_pool() - create a new z3fold pool 751d30561c5SVitaly Wool * @name: pool name 752d30561c5SVitaly Wool * @gfp: gfp flags when allocating the z3fold pool structure 753d30561c5SVitaly Wool * @ops: user-defined operations for the z3fold pool 754d30561c5SVitaly Wool * 755d30561c5SVitaly Wool * Return: pointer to the new z3fold pool or NULL if the metadata allocation 756d30561c5SVitaly Wool * failed. 757d30561c5SVitaly Wool */ 758d30561c5SVitaly Wool static struct z3fold_pool *z3fold_create_pool(const char *name, gfp_t gfp, 759d30561c5SVitaly Wool const struct z3fold_ops *ops) 760d30561c5SVitaly Wool { 761d30561c5SVitaly Wool struct z3fold_pool *pool = NULL; 762d30561c5SVitaly Wool int i, cpu; 763d30561c5SVitaly Wool 764d30561c5SVitaly Wool pool = kzalloc(sizeof(struct z3fold_pool), gfp); 765d30561c5SVitaly Wool if (!pool) 766d30561c5SVitaly Wool goto out; 7677c2b8baaSVitaly Wool pool->c_handle = kmem_cache_create("z3fold_handle", 7687c2b8baaSVitaly Wool sizeof(struct z3fold_buddy_slots), 7697c2b8baaSVitaly Wool SLOTS_ALIGN, 0, NULL); 7707c2b8baaSVitaly Wool if (!pool->c_handle) 7717c2b8baaSVitaly Wool goto out_c; 772d30561c5SVitaly Wool spin_lock_init(&pool->lock); 773d30561c5SVitaly Wool spin_lock_init(&pool->stale_lock); 774d30561c5SVitaly Wool pool->unbuddied = __alloc_percpu(sizeof(struct list_head)*NCHUNKS, 2); 7751ec6995dSXidong Wang if (!pool->unbuddied) 7761ec6995dSXidong Wang goto out_pool; 777d30561c5SVitaly Wool for_each_possible_cpu(cpu) { 778d30561c5SVitaly Wool struct list_head *unbuddied = 779d30561c5SVitaly Wool per_cpu_ptr(pool->unbuddied, cpu); 780d30561c5SVitaly Wool for_each_unbuddied_list(i, 0) 781d30561c5SVitaly Wool INIT_LIST_HEAD(&unbuddied[i]); 782d30561c5SVitaly Wool } 783d30561c5SVitaly Wool INIT_LIST_HEAD(&pool->lru); 784d30561c5SVitaly Wool INIT_LIST_HEAD(&pool->stale); 785d30561c5SVitaly Wool atomic64_set(&pool->pages_nr, 0); 786d30561c5SVitaly Wool pool->name = name; 787d30561c5SVitaly Wool pool->compact_wq = create_singlethread_workqueue(pool->name); 788d30561c5SVitaly Wool if (!pool->compact_wq) 7891ec6995dSXidong Wang goto out_unbuddied; 790d30561c5SVitaly Wool pool->release_wq = create_singlethread_workqueue(pool->name); 791d30561c5SVitaly Wool if (!pool->release_wq) 792d30561c5SVitaly Wool goto out_wq; 7931f862989SVitaly Wool if (z3fold_register_migration(pool)) 7941f862989SVitaly Wool goto out_rwq; 795d30561c5SVitaly Wool INIT_WORK(&pool->work, free_pages_work); 796d30561c5SVitaly Wool pool->ops = ops; 797d30561c5SVitaly Wool return pool; 798d30561c5SVitaly Wool 7991f862989SVitaly Wool out_rwq: 8001f862989SVitaly Wool destroy_workqueue(pool->release_wq); 801d30561c5SVitaly Wool out_wq: 802d30561c5SVitaly Wool destroy_workqueue(pool->compact_wq); 8031ec6995dSXidong Wang out_unbuddied: 8041ec6995dSXidong Wang free_percpu(pool->unbuddied); 8051ec6995dSXidong Wang out_pool: 8067c2b8baaSVitaly Wool kmem_cache_destroy(pool->c_handle); 8077c2b8baaSVitaly Wool out_c: 808d30561c5SVitaly Wool kfree(pool); 8091ec6995dSXidong Wang out: 810d30561c5SVitaly Wool return NULL; 811d30561c5SVitaly Wool } 812d30561c5SVitaly Wool 813d30561c5SVitaly Wool /** 814d30561c5SVitaly Wool * z3fold_destroy_pool() - destroys an existing z3fold pool 815d30561c5SVitaly Wool * @pool: the z3fold pool to be destroyed 816d30561c5SVitaly Wool * 817d30561c5SVitaly Wool * The pool should be emptied before this function is called. 818d30561c5SVitaly Wool */ 819d30561c5SVitaly Wool static void z3fold_destroy_pool(struct z3fold_pool *pool) 820d30561c5SVitaly Wool { 8217c2b8baaSVitaly Wool kmem_cache_destroy(pool->c_handle); 8221f862989SVitaly Wool z3fold_unregister_migration(pool); 823d30561c5SVitaly Wool destroy_workqueue(pool->release_wq); 824d30561c5SVitaly Wool destroy_workqueue(pool->compact_wq); 825d30561c5SVitaly Wool kfree(pool); 826d30561c5SVitaly Wool } 827d30561c5SVitaly Wool 8289a001fc1SVitaly Wool /** 8299a001fc1SVitaly Wool * z3fold_alloc() - allocates a region of a given size 8309a001fc1SVitaly Wool * @pool: z3fold pool from which to allocate 8319a001fc1SVitaly Wool * @size: size in bytes of the desired allocation 8329a001fc1SVitaly Wool * @gfp: gfp flags used if the pool needs to grow 8339a001fc1SVitaly Wool * @handle: handle of the new allocation 8349a001fc1SVitaly Wool * 8359a001fc1SVitaly Wool * This function will attempt to find a free region in the pool large enough to 8369a001fc1SVitaly Wool * satisfy the allocation request. A search of the unbuddied lists is 8379a001fc1SVitaly Wool * performed first. If no suitable free region is found, then a new page is 8389a001fc1SVitaly Wool * allocated and added to the pool to satisfy the request. 8399a001fc1SVitaly Wool * 8409a001fc1SVitaly Wool * gfp should not set __GFP_HIGHMEM as highmem pages cannot be used 8419a001fc1SVitaly Wool * as z3fold pool pages. 8429a001fc1SVitaly Wool * 8439a001fc1SVitaly Wool * Return: 0 if success and handle is set, otherwise -EINVAL if the size or 8449a001fc1SVitaly Wool * gfp arguments are invalid or -ENOMEM if the pool was unable to allocate 8459a001fc1SVitaly Wool * a new page. 8469a001fc1SVitaly Wool */ 8479a001fc1SVitaly Wool static int z3fold_alloc(struct z3fold_pool *pool, size_t size, gfp_t gfp, 8489a001fc1SVitaly Wool unsigned long *handle) 8499a001fc1SVitaly Wool { 8509050cce1SVitaly Wool int chunks = size_to_chunks(size); 8519a001fc1SVitaly Wool struct z3fold_header *zhdr = NULL; 852d30561c5SVitaly Wool struct page *page = NULL; 8539a001fc1SVitaly Wool enum buddy bud; 8548a97ea54SMatthew Wilcox bool can_sleep = gfpflags_allow_blocking(gfp); 8559a001fc1SVitaly Wool 8569a001fc1SVitaly Wool if (!size || (gfp & __GFP_HIGHMEM)) 8579a001fc1SVitaly Wool return -EINVAL; 8589a001fc1SVitaly Wool 8599a001fc1SVitaly Wool if (size > PAGE_SIZE) 8609a001fc1SVitaly Wool return -ENOSPC; 8619a001fc1SVitaly Wool 8629a001fc1SVitaly Wool if (size > PAGE_SIZE - ZHDR_SIZE_ALIGNED - CHUNK_SIZE) 8639a001fc1SVitaly Wool bud = HEADLESS; 8649a001fc1SVitaly Wool else { 8659050cce1SVitaly Wool retry: 8669050cce1SVitaly Wool zhdr = __z3fold_alloc(pool, size, can_sleep); 867d30561c5SVitaly Wool if (zhdr) { 8689a001fc1SVitaly Wool if (zhdr->first_chunks == 0) { 8699a001fc1SVitaly Wool if (zhdr->middle_chunks != 0 && 8709a001fc1SVitaly Wool chunks >= zhdr->start_middle) 8719a001fc1SVitaly Wool bud = LAST; 8729a001fc1SVitaly Wool else 8739a001fc1SVitaly Wool bud = FIRST; 8749a001fc1SVitaly Wool } else if (zhdr->last_chunks == 0) 8759a001fc1SVitaly Wool bud = LAST; 8769a001fc1SVitaly Wool else if (zhdr->middle_chunks == 0) 8779a001fc1SVitaly Wool bud = MIDDLE; 8789a001fc1SVitaly Wool else { 8795a27aa82SVitaly Wool if (kref_put(&zhdr->refcount, 880d30561c5SVitaly Wool release_z3fold_page_locked)) 8815a27aa82SVitaly Wool atomic64_dec(&pool->pages_nr); 882d30561c5SVitaly Wool else 883d30561c5SVitaly Wool z3fold_page_unlock(zhdr); 8849a001fc1SVitaly Wool pr_err("No free chunks in unbuddied\n"); 8859a001fc1SVitaly Wool WARN_ON(1); 8869050cce1SVitaly Wool goto retry; 8879a001fc1SVitaly Wool } 8889050cce1SVitaly Wool page = virt_to_page(zhdr); 8899a001fc1SVitaly Wool goto found; 8909a001fc1SVitaly Wool } 8919a001fc1SVitaly Wool bud = FIRST; 8929a001fc1SVitaly Wool } 8939a001fc1SVitaly Wool 8945c9bab59SVitaly Wool page = NULL; 8955c9bab59SVitaly Wool if (can_sleep) { 896d30561c5SVitaly Wool spin_lock(&pool->stale_lock); 897d30561c5SVitaly Wool zhdr = list_first_entry_or_null(&pool->stale, 898d30561c5SVitaly Wool struct z3fold_header, buddy); 899d30561c5SVitaly Wool /* 9005c9bab59SVitaly Wool * Before allocating a page, let's see if we can take one from 9015c9bab59SVitaly Wool * the stale pages list. cancel_work_sync() can sleep so we 9025c9bab59SVitaly Wool * limit this case to the contexts where we can sleep 903d30561c5SVitaly Wool */ 9045c9bab59SVitaly Wool if (zhdr) { 905d30561c5SVitaly Wool list_del(&zhdr->buddy); 906d30561c5SVitaly Wool spin_unlock(&pool->stale_lock); 907d30561c5SVitaly Wool cancel_work_sync(&zhdr->work); 908d30561c5SVitaly Wool page = virt_to_page(zhdr); 909d30561c5SVitaly Wool } else { 910d30561c5SVitaly Wool spin_unlock(&pool->stale_lock); 911d30561c5SVitaly Wool } 9125c9bab59SVitaly Wool } 9135c9bab59SVitaly Wool if (!page) 9145c9bab59SVitaly Wool page = alloc_page(gfp); 915d30561c5SVitaly Wool 9169a001fc1SVitaly Wool if (!page) 9179a001fc1SVitaly Wool return -ENOMEM; 9182f1e5e4dSVitaly Wool 919bb9f6f63SVitaly Wool zhdr = init_z3fold_page(page, pool, gfp); 9209050cce1SVitaly Wool if (!zhdr) { 9219050cce1SVitaly Wool __free_page(page); 9229050cce1SVitaly Wool return -ENOMEM; 9239050cce1SVitaly Wool } 9249050cce1SVitaly Wool atomic64_inc(&pool->pages_nr); 9259a001fc1SVitaly Wool 9269a001fc1SVitaly Wool if (bud == HEADLESS) { 9279a001fc1SVitaly Wool set_bit(PAGE_HEADLESS, &page->private); 9289a001fc1SVitaly Wool goto headless; 9299a001fc1SVitaly Wool } 930810481a2SHenry Burns if (can_sleep) { 931810481a2SHenry Burns lock_page(page); 9321f862989SVitaly Wool __SetPageMovable(page, pool->inode->i_mapping); 933810481a2SHenry Burns unlock_page(page); 934810481a2SHenry Burns } else { 935810481a2SHenry Burns if (trylock_page(page)) { 936810481a2SHenry Burns __SetPageMovable(page, pool->inode->i_mapping); 937810481a2SHenry Burns unlock_page(page); 938810481a2SHenry Burns } 939810481a2SHenry Burns } 9402f1e5e4dSVitaly Wool z3fold_page_lock(zhdr); 9419a001fc1SVitaly Wool 9429a001fc1SVitaly Wool found: 9439a001fc1SVitaly Wool if (bud == FIRST) 9449a001fc1SVitaly Wool zhdr->first_chunks = chunks; 9459a001fc1SVitaly Wool else if (bud == LAST) 9469a001fc1SVitaly Wool zhdr->last_chunks = chunks; 9479a001fc1SVitaly Wool else { 9489a001fc1SVitaly Wool zhdr->middle_chunks = chunks; 949ede93213SVitaly Wool zhdr->start_middle = zhdr->first_chunks + ZHDR_CHUNKS; 9509a001fc1SVitaly Wool } 9519050cce1SVitaly Wool add_to_unbuddied(pool, zhdr); 9529a001fc1SVitaly Wool 9539a001fc1SVitaly Wool headless: 954d30561c5SVitaly Wool spin_lock(&pool->lock); 9559a001fc1SVitaly Wool /* Add/move z3fold page to beginning of LRU */ 9569a001fc1SVitaly Wool if (!list_empty(&page->lru)) 9579a001fc1SVitaly Wool list_del(&page->lru); 9589a001fc1SVitaly Wool 9599a001fc1SVitaly Wool list_add(&page->lru, &pool->lru); 9609a001fc1SVitaly Wool 9619a001fc1SVitaly Wool *handle = encode_handle(zhdr, bud); 9629a001fc1SVitaly Wool spin_unlock(&pool->lock); 9632f1e5e4dSVitaly Wool if (bud != HEADLESS) 9642f1e5e4dSVitaly Wool z3fold_page_unlock(zhdr); 9659a001fc1SVitaly Wool 9669a001fc1SVitaly Wool return 0; 9679a001fc1SVitaly Wool } 9689a001fc1SVitaly Wool 9699a001fc1SVitaly Wool /** 9709a001fc1SVitaly Wool * z3fold_free() - frees the allocation associated with the given handle 9719a001fc1SVitaly Wool * @pool: pool in which the allocation resided 9729a001fc1SVitaly Wool * @handle: handle associated with the allocation returned by z3fold_alloc() 9739a001fc1SVitaly Wool * 9749a001fc1SVitaly Wool * In the case that the z3fold page in which the allocation resides is under 9759a001fc1SVitaly Wool * reclaim, as indicated by the PG_reclaim flag being set, this function 9769a001fc1SVitaly Wool * only sets the first|last_chunks to 0. The page is actually freed 9779a001fc1SVitaly Wool * once both buddies are evicted (see z3fold_reclaim_page() below). 9789a001fc1SVitaly Wool */ 9799a001fc1SVitaly Wool static void z3fold_free(struct z3fold_pool *pool, unsigned long handle) 9809a001fc1SVitaly Wool { 9819a001fc1SVitaly Wool struct z3fold_header *zhdr; 9829a001fc1SVitaly Wool struct page *page; 9839a001fc1SVitaly Wool enum buddy bud; 9849a001fc1SVitaly Wool 9859a001fc1SVitaly Wool zhdr = handle_to_z3fold_header(handle); 9869a001fc1SVitaly Wool page = virt_to_page(zhdr); 9879a001fc1SVitaly Wool 9889a001fc1SVitaly Wool if (test_bit(PAGE_HEADLESS, &page->private)) { 989ca0246bbSVitaly Wool /* if a headless page is under reclaim, just leave. 990ca0246bbSVitaly Wool * NB: we use test_and_set_bit for a reason: if the bit 991ca0246bbSVitaly Wool * has not been set before, we release this page 992ca0246bbSVitaly Wool * immediately so we don't care about its value any more. 993ca0246bbSVitaly Wool */ 994ca0246bbSVitaly Wool if (!test_and_set_bit(PAGE_CLAIMED, &page->private)) { 995ca0246bbSVitaly Wool spin_lock(&pool->lock); 996ca0246bbSVitaly Wool list_del(&page->lru); 997ca0246bbSVitaly Wool spin_unlock(&pool->lock); 9981f862989SVitaly Wool free_z3fold_page(page, true); 999ca0246bbSVitaly Wool atomic64_dec(&pool->pages_nr); 1000ca0246bbSVitaly Wool } 1001ca0246bbSVitaly Wool return; 1002ca0246bbSVitaly Wool } 1003ca0246bbSVitaly Wool 1004ca0246bbSVitaly Wool /* Non-headless case */ 10052f1e5e4dSVitaly Wool z3fold_page_lock(zhdr); 100643afc194SVitaly Wool bud = handle_to_buddy(handle); 10079a001fc1SVitaly Wool 10089a001fc1SVitaly Wool switch (bud) { 10099a001fc1SVitaly Wool case FIRST: 10109a001fc1SVitaly Wool zhdr->first_chunks = 0; 10119a001fc1SVitaly Wool break; 10129a001fc1SVitaly Wool case MIDDLE: 10139a001fc1SVitaly Wool zhdr->middle_chunks = 0; 10149a001fc1SVitaly Wool break; 10159a001fc1SVitaly Wool case LAST: 10169a001fc1SVitaly Wool zhdr->last_chunks = 0; 10179a001fc1SVitaly Wool break; 10189a001fc1SVitaly Wool default: 10199a001fc1SVitaly Wool pr_err("%s: unknown bud %d\n", __func__, bud); 10209a001fc1SVitaly Wool WARN_ON(1); 10212f1e5e4dSVitaly Wool z3fold_page_unlock(zhdr); 10229a001fc1SVitaly Wool return; 10239a001fc1SVitaly Wool } 10249a001fc1SVitaly Wool 10257c2b8baaSVitaly Wool free_handle(handle); 1026d30561c5SVitaly Wool if (kref_put(&zhdr->refcount, release_z3fold_page_locked_list)) { 1027d30561c5SVitaly Wool atomic64_dec(&pool->pages_nr); 1028d30561c5SVitaly Wool return; 1029d30561c5SVitaly Wool } 1030ca0246bbSVitaly Wool if (test_bit(PAGE_CLAIMED, &page->private)) { 10316098d7e1SVitaly Wool z3fold_page_unlock(zhdr); 10326098d7e1SVitaly Wool return; 10336098d7e1SVitaly Wool } 10341f862989SVitaly Wool if (unlikely(PageIsolated(page)) || 10351f862989SVitaly Wool test_and_set_bit(NEEDS_COMPACTING, &page->private)) { 1036d30561c5SVitaly Wool z3fold_page_unlock(zhdr); 1037d30561c5SVitaly Wool return; 1038d30561c5SVitaly Wool } 1039d30561c5SVitaly Wool if (zhdr->cpu < 0 || !cpu_online(zhdr->cpu)) { 1040d30561c5SVitaly Wool spin_lock(&pool->lock); 1041d30561c5SVitaly Wool list_del_init(&zhdr->buddy); 1042d30561c5SVitaly Wool spin_unlock(&pool->lock); 1043d30561c5SVitaly Wool zhdr->cpu = -1; 10445d03a661SVitaly Wool kref_get(&zhdr->refcount); 1045d30561c5SVitaly Wool do_compact_page(zhdr, true); 1046d30561c5SVitaly Wool return; 1047d30561c5SVitaly Wool } 10485d03a661SVitaly Wool kref_get(&zhdr->refcount); 1049d30561c5SVitaly Wool queue_work_on(zhdr->cpu, pool->compact_wq, &zhdr->work); 1050d30561c5SVitaly Wool z3fold_page_unlock(zhdr); 10519a001fc1SVitaly Wool } 10529a001fc1SVitaly Wool 10539a001fc1SVitaly Wool /** 10549a001fc1SVitaly Wool * z3fold_reclaim_page() - evicts allocations from a pool page and frees it 10559a001fc1SVitaly Wool * @pool: pool from which a page will attempt to be evicted 1056f144c390SMike Rapoport * @retries: number of pages on the LRU list for which eviction will 10579a001fc1SVitaly Wool * be attempted before failing 10589a001fc1SVitaly Wool * 10599a001fc1SVitaly Wool * z3fold reclaim is different from normal system reclaim in that it is done 10609a001fc1SVitaly Wool * from the bottom, up. This is because only the bottom layer, z3fold, has 10619a001fc1SVitaly Wool * information on how the allocations are organized within each z3fold page. 10629a001fc1SVitaly Wool * This has the potential to create interesting locking situations between 10639a001fc1SVitaly Wool * z3fold and the user, however. 10649a001fc1SVitaly Wool * 10659a001fc1SVitaly Wool * To avoid these, this is how z3fold_reclaim_page() should be called: 1066f144c390SMike Rapoport * 10679a001fc1SVitaly Wool * The user detects a page should be reclaimed and calls z3fold_reclaim_page(). 10689a001fc1SVitaly Wool * z3fold_reclaim_page() will remove a z3fold page from the pool LRU list and 10699a001fc1SVitaly Wool * call the user-defined eviction handler with the pool and handle as 10709a001fc1SVitaly Wool * arguments. 10719a001fc1SVitaly Wool * 10729a001fc1SVitaly Wool * If the handle can not be evicted, the eviction handler should return 10739a001fc1SVitaly Wool * non-zero. z3fold_reclaim_page() will add the z3fold page back to the 10749a001fc1SVitaly Wool * appropriate list and try the next z3fold page on the LRU up to 10759a001fc1SVitaly Wool * a user defined number of retries. 10769a001fc1SVitaly Wool * 10779a001fc1SVitaly Wool * If the handle is successfully evicted, the eviction handler should 10789a001fc1SVitaly Wool * return 0 _and_ should have called z3fold_free() on the handle. z3fold_free() 10799a001fc1SVitaly Wool * contains logic to delay freeing the page if the page is under reclaim, 10809a001fc1SVitaly Wool * as indicated by the setting of the PG_reclaim flag on the underlying page. 10819a001fc1SVitaly Wool * 10829a001fc1SVitaly Wool * If all buddies in the z3fold page are successfully evicted, then the 10839a001fc1SVitaly Wool * z3fold page can be freed. 10849a001fc1SVitaly Wool * 10859a001fc1SVitaly Wool * Returns: 0 if page is successfully freed, otherwise -EINVAL if there are 10869a001fc1SVitaly Wool * no pages to evict or an eviction handler is not registered, -EAGAIN if 10879a001fc1SVitaly Wool * the retry limit was hit. 10889a001fc1SVitaly Wool */ 10899a001fc1SVitaly Wool static int z3fold_reclaim_page(struct z3fold_pool *pool, unsigned int retries) 10909a001fc1SVitaly Wool { 1091d30561c5SVitaly Wool int i, ret = 0; 1092d30561c5SVitaly Wool struct z3fold_header *zhdr = NULL; 1093d30561c5SVitaly Wool struct page *page = NULL; 1094d30561c5SVitaly Wool struct list_head *pos; 10959a001fc1SVitaly Wool unsigned long first_handle = 0, middle_handle = 0, last_handle = 0; 10969a001fc1SVitaly Wool 10979a001fc1SVitaly Wool spin_lock(&pool->lock); 10982f1e5e4dSVitaly Wool if (!pool->ops || !pool->ops->evict || retries == 0) { 10999a001fc1SVitaly Wool spin_unlock(&pool->lock); 11009a001fc1SVitaly Wool return -EINVAL; 11019a001fc1SVitaly Wool } 11029a001fc1SVitaly Wool for (i = 0; i < retries; i++) { 11032f1e5e4dSVitaly Wool if (list_empty(&pool->lru)) { 11042f1e5e4dSVitaly Wool spin_unlock(&pool->lock); 11052f1e5e4dSVitaly Wool return -EINVAL; 11062f1e5e4dSVitaly Wool } 1107d30561c5SVitaly Wool list_for_each_prev(pos, &pool->lru) { 1108d30561c5SVitaly Wool page = list_entry(pos, struct page, lru); 1109ca0246bbSVitaly Wool 1110ca0246bbSVitaly Wool /* this bit could have been set by free, in which case 1111ca0246bbSVitaly Wool * we pass over to the next page in the pool. 1112ca0246bbSVitaly Wool */ 1113ca0246bbSVitaly Wool if (test_and_set_bit(PAGE_CLAIMED, &page->private)) 1114ca0246bbSVitaly Wool continue; 11159a001fc1SVitaly Wool 11161f862989SVitaly Wool if (unlikely(PageIsolated(page))) 11171f862989SVitaly Wool continue; 1118ca0246bbSVitaly Wool if (test_bit(PAGE_HEADLESS, &page->private)) 1119ca0246bbSVitaly Wool break; 1120ca0246bbSVitaly Wool 11211f862989SVitaly Wool zhdr = page_address(page); 1122ca0246bbSVitaly Wool if (!z3fold_page_trylock(zhdr)) { 1123ca0246bbSVitaly Wool zhdr = NULL; 1124d30561c5SVitaly Wool continue; /* can't evict at this point */ 1125ca0246bbSVitaly Wool } 11265a27aa82SVitaly Wool kref_get(&zhdr->refcount); 1127d30561c5SVitaly Wool list_del_init(&zhdr->buddy); 1128d30561c5SVitaly Wool zhdr->cpu = -1; 11296098d7e1SVitaly Wool break; 1130d30561c5SVitaly Wool } 1131d30561c5SVitaly Wool 1132ca0246bbSVitaly Wool if (!zhdr) 1133ca0246bbSVitaly Wool break; 1134ca0246bbSVitaly Wool 1135d30561c5SVitaly Wool list_del_init(&page->lru); 11362f1e5e4dSVitaly Wool spin_unlock(&pool->lock); 1137d30561c5SVitaly Wool 1138d30561c5SVitaly Wool if (!test_bit(PAGE_HEADLESS, &page->private)) { 11399a001fc1SVitaly Wool /* 11409a001fc1SVitaly Wool * We need encode the handles before unlocking, since 11419a001fc1SVitaly Wool * we can race with free that will set 11429a001fc1SVitaly Wool * (first|last)_chunks to 0 11439a001fc1SVitaly Wool */ 11449a001fc1SVitaly Wool first_handle = 0; 11459a001fc1SVitaly Wool last_handle = 0; 11469a001fc1SVitaly Wool middle_handle = 0; 11479a001fc1SVitaly Wool if (zhdr->first_chunks) 11489a001fc1SVitaly Wool first_handle = encode_handle(zhdr, FIRST); 11499a001fc1SVitaly Wool if (zhdr->middle_chunks) 11509a001fc1SVitaly Wool middle_handle = encode_handle(zhdr, MIDDLE); 11519a001fc1SVitaly Wool if (zhdr->last_chunks) 11529a001fc1SVitaly Wool last_handle = encode_handle(zhdr, LAST); 1153d30561c5SVitaly Wool /* 1154d30561c5SVitaly Wool * it's safe to unlock here because we hold a 1155d30561c5SVitaly Wool * reference to this page 1156d30561c5SVitaly Wool */ 11572f1e5e4dSVitaly Wool z3fold_page_unlock(zhdr); 11589a001fc1SVitaly Wool } else { 11599a001fc1SVitaly Wool first_handle = encode_handle(zhdr, HEADLESS); 11609a001fc1SVitaly Wool last_handle = middle_handle = 0; 11612f1e5e4dSVitaly Wool } 11629a001fc1SVitaly Wool 11639a001fc1SVitaly Wool /* Issue the eviction callback(s) */ 11649a001fc1SVitaly Wool if (middle_handle) { 11659a001fc1SVitaly Wool ret = pool->ops->evict(pool, middle_handle); 11669a001fc1SVitaly Wool if (ret) 11679a001fc1SVitaly Wool goto next; 11689a001fc1SVitaly Wool } 11699a001fc1SVitaly Wool if (first_handle) { 11709a001fc1SVitaly Wool ret = pool->ops->evict(pool, first_handle); 11719a001fc1SVitaly Wool if (ret) 11729a001fc1SVitaly Wool goto next; 11739a001fc1SVitaly Wool } 11749a001fc1SVitaly Wool if (last_handle) { 11759a001fc1SVitaly Wool ret = pool->ops->evict(pool, last_handle); 11769a001fc1SVitaly Wool if (ret) 11779a001fc1SVitaly Wool goto next; 11789a001fc1SVitaly Wool } 11799a001fc1SVitaly Wool next: 11805a27aa82SVitaly Wool if (test_bit(PAGE_HEADLESS, &page->private)) { 11815a27aa82SVitaly Wool if (ret == 0) { 11821f862989SVitaly Wool free_z3fold_page(page, true); 1183ca0246bbSVitaly Wool atomic64_dec(&pool->pages_nr); 11849a001fc1SVitaly Wool return 0; 11855a27aa82SVitaly Wool } 11866098d7e1SVitaly Wool spin_lock(&pool->lock); 11876098d7e1SVitaly Wool list_add(&page->lru, &pool->lru); 1188d5567c9dSVitaly Wool spin_unlock(&pool->lock); 11896098d7e1SVitaly Wool } else { 11906098d7e1SVitaly Wool z3fold_page_lock(zhdr); 1191ca0246bbSVitaly Wool clear_bit(PAGE_CLAIMED, &page->private); 11926098d7e1SVitaly Wool if (kref_put(&zhdr->refcount, 11936098d7e1SVitaly Wool release_z3fold_page_locked)) { 11946098d7e1SVitaly Wool atomic64_dec(&pool->pages_nr); 11955a27aa82SVitaly Wool return 0; 11965a27aa82SVitaly Wool } 11975a27aa82SVitaly Wool /* 11986098d7e1SVitaly Wool * if we are here, the page is still not completely 11996098d7e1SVitaly Wool * free. Take the global pool lock then to be able 12006098d7e1SVitaly Wool * to add it back to the lru list 12015a27aa82SVitaly Wool */ 12026098d7e1SVitaly Wool spin_lock(&pool->lock); 12039a001fc1SVitaly Wool list_add(&page->lru, &pool->lru); 12046098d7e1SVitaly Wool spin_unlock(&pool->lock); 12056098d7e1SVitaly Wool z3fold_page_unlock(zhdr); 12066098d7e1SVitaly Wool } 12076098d7e1SVitaly Wool 12086098d7e1SVitaly Wool /* We started off locked to we need to lock the pool back */ 12096098d7e1SVitaly Wool spin_lock(&pool->lock); 12109a001fc1SVitaly Wool } 12119a001fc1SVitaly Wool spin_unlock(&pool->lock); 12129a001fc1SVitaly Wool return -EAGAIN; 12139a001fc1SVitaly Wool } 12149a001fc1SVitaly Wool 12159a001fc1SVitaly Wool /** 12169a001fc1SVitaly Wool * z3fold_map() - maps the allocation associated with the given handle 12179a001fc1SVitaly Wool * @pool: pool in which the allocation resides 12189a001fc1SVitaly Wool * @handle: handle associated with the allocation to be mapped 12199a001fc1SVitaly Wool * 12209a001fc1SVitaly Wool * Extracts the buddy number from handle and constructs the pointer to the 12219a001fc1SVitaly Wool * correct starting chunk within the page. 12229a001fc1SVitaly Wool * 12239a001fc1SVitaly Wool * Returns: a pointer to the mapped allocation 12249a001fc1SVitaly Wool */ 12259a001fc1SVitaly Wool static void *z3fold_map(struct z3fold_pool *pool, unsigned long handle) 12269a001fc1SVitaly Wool { 12279a001fc1SVitaly Wool struct z3fold_header *zhdr; 12289a001fc1SVitaly Wool struct page *page; 12299a001fc1SVitaly Wool void *addr; 12309a001fc1SVitaly Wool enum buddy buddy; 12319a001fc1SVitaly Wool 12329a001fc1SVitaly Wool zhdr = handle_to_z3fold_header(handle); 12339a001fc1SVitaly Wool addr = zhdr; 12349a001fc1SVitaly Wool page = virt_to_page(zhdr); 12359a001fc1SVitaly Wool 12369a001fc1SVitaly Wool if (test_bit(PAGE_HEADLESS, &page->private)) 12379a001fc1SVitaly Wool goto out; 12389a001fc1SVitaly Wool 12392f1e5e4dSVitaly Wool z3fold_page_lock(zhdr); 12409a001fc1SVitaly Wool buddy = handle_to_buddy(handle); 12419a001fc1SVitaly Wool switch (buddy) { 12429a001fc1SVitaly Wool case FIRST: 12439a001fc1SVitaly Wool addr += ZHDR_SIZE_ALIGNED; 12449a001fc1SVitaly Wool break; 12459a001fc1SVitaly Wool case MIDDLE: 12469a001fc1SVitaly Wool addr += zhdr->start_middle << CHUNK_SHIFT; 12479a001fc1SVitaly Wool set_bit(MIDDLE_CHUNK_MAPPED, &page->private); 12489a001fc1SVitaly Wool break; 12499a001fc1SVitaly Wool case LAST: 1250ca0246bbSVitaly Wool addr += PAGE_SIZE - (handle_to_chunks(handle) << CHUNK_SHIFT); 12519a001fc1SVitaly Wool break; 12529a001fc1SVitaly Wool default: 12539a001fc1SVitaly Wool pr_err("unknown buddy id %d\n", buddy); 12549a001fc1SVitaly Wool WARN_ON(1); 12559a001fc1SVitaly Wool addr = NULL; 12569a001fc1SVitaly Wool break; 12579a001fc1SVitaly Wool } 12582f1e5e4dSVitaly Wool 12591f862989SVitaly Wool if (addr) 12601f862989SVitaly Wool zhdr->mapped_count++; 12612f1e5e4dSVitaly Wool z3fold_page_unlock(zhdr); 12629a001fc1SVitaly Wool out: 12639a001fc1SVitaly Wool return addr; 12649a001fc1SVitaly Wool } 12659a001fc1SVitaly Wool 12669a001fc1SVitaly Wool /** 12679a001fc1SVitaly Wool * z3fold_unmap() - unmaps the allocation associated with the given handle 12689a001fc1SVitaly Wool * @pool: pool in which the allocation resides 12699a001fc1SVitaly Wool * @handle: handle associated with the allocation to be unmapped 12709a001fc1SVitaly Wool */ 12719a001fc1SVitaly Wool static void z3fold_unmap(struct z3fold_pool *pool, unsigned long handle) 12729a001fc1SVitaly Wool { 12739a001fc1SVitaly Wool struct z3fold_header *zhdr; 12749a001fc1SVitaly Wool struct page *page; 12759a001fc1SVitaly Wool enum buddy buddy; 12769a001fc1SVitaly Wool 12779a001fc1SVitaly Wool zhdr = handle_to_z3fold_header(handle); 12789a001fc1SVitaly Wool page = virt_to_page(zhdr); 12799a001fc1SVitaly Wool 12802f1e5e4dSVitaly Wool if (test_bit(PAGE_HEADLESS, &page->private)) 12819a001fc1SVitaly Wool return; 12829a001fc1SVitaly Wool 12832f1e5e4dSVitaly Wool z3fold_page_lock(zhdr); 12849a001fc1SVitaly Wool buddy = handle_to_buddy(handle); 12859a001fc1SVitaly Wool if (buddy == MIDDLE) 12869a001fc1SVitaly Wool clear_bit(MIDDLE_CHUNK_MAPPED, &page->private); 12871f862989SVitaly Wool zhdr->mapped_count--; 12882f1e5e4dSVitaly Wool z3fold_page_unlock(zhdr); 12899a001fc1SVitaly Wool } 12909a001fc1SVitaly Wool 12919a001fc1SVitaly Wool /** 12929a001fc1SVitaly Wool * z3fold_get_pool_size() - gets the z3fold pool size in pages 12939a001fc1SVitaly Wool * @pool: pool whose size is being queried 12949a001fc1SVitaly Wool * 129512d59ae6SVitaly Wool * Returns: size in pages of the given pool. 12969a001fc1SVitaly Wool */ 12979a001fc1SVitaly Wool static u64 z3fold_get_pool_size(struct z3fold_pool *pool) 12989a001fc1SVitaly Wool { 129912d59ae6SVitaly Wool return atomic64_read(&pool->pages_nr); 13009a001fc1SVitaly Wool } 13019a001fc1SVitaly Wool 13021f862989SVitaly Wool static bool z3fold_page_isolate(struct page *page, isolate_mode_t mode) 13031f862989SVitaly Wool { 13041f862989SVitaly Wool struct z3fold_header *zhdr; 13051f862989SVitaly Wool struct z3fold_pool *pool; 13061f862989SVitaly Wool 13071f862989SVitaly Wool VM_BUG_ON_PAGE(!PageMovable(page), page); 13081f862989SVitaly Wool VM_BUG_ON_PAGE(PageIsolated(page), page); 13091f862989SVitaly Wool 13101f862989SVitaly Wool if (test_bit(PAGE_HEADLESS, &page->private)) 13111f862989SVitaly Wool return false; 13121f862989SVitaly Wool 13131f862989SVitaly Wool zhdr = page_address(page); 13141f862989SVitaly Wool z3fold_page_lock(zhdr); 13151f862989SVitaly Wool if (test_bit(NEEDS_COMPACTING, &page->private) || 13161f862989SVitaly Wool test_bit(PAGE_STALE, &page->private)) 13171f862989SVitaly Wool goto out; 13181f862989SVitaly Wool 13191f862989SVitaly Wool pool = zhdr_to_pool(zhdr); 13201f862989SVitaly Wool 13211f862989SVitaly Wool if (zhdr->mapped_count == 0) { 13221f862989SVitaly Wool kref_get(&zhdr->refcount); 13231f862989SVitaly Wool if (!list_empty(&zhdr->buddy)) 13241f862989SVitaly Wool list_del_init(&zhdr->buddy); 13251f862989SVitaly Wool spin_lock(&pool->lock); 13261f862989SVitaly Wool if (!list_empty(&page->lru)) 13271f862989SVitaly Wool list_del(&page->lru); 13281f862989SVitaly Wool spin_unlock(&pool->lock); 13291f862989SVitaly Wool z3fold_page_unlock(zhdr); 13301f862989SVitaly Wool return true; 13311f862989SVitaly Wool } 13321f862989SVitaly Wool out: 13331f862989SVitaly Wool z3fold_page_unlock(zhdr); 13341f862989SVitaly Wool return false; 13351f862989SVitaly Wool } 13361f862989SVitaly Wool 13371f862989SVitaly Wool static int z3fold_page_migrate(struct address_space *mapping, struct page *newpage, 13381f862989SVitaly Wool struct page *page, enum migrate_mode mode) 13391f862989SVitaly Wool { 13401f862989SVitaly Wool struct z3fold_header *zhdr, *new_zhdr; 13411f862989SVitaly Wool struct z3fold_pool *pool; 13421f862989SVitaly Wool struct address_space *new_mapping; 13431f862989SVitaly Wool 13441f862989SVitaly Wool VM_BUG_ON_PAGE(!PageMovable(page), page); 13451f862989SVitaly Wool VM_BUG_ON_PAGE(!PageIsolated(page), page); 1346810481a2SHenry Burns VM_BUG_ON_PAGE(!PageLocked(newpage), newpage); 13471f862989SVitaly Wool 13481f862989SVitaly Wool zhdr = page_address(page); 13491f862989SVitaly Wool pool = zhdr_to_pool(zhdr); 13501f862989SVitaly Wool 13511f862989SVitaly Wool if (!trylock_page(page)) 13521f862989SVitaly Wool return -EAGAIN; 13531f862989SVitaly Wool 13541f862989SVitaly Wool if (!z3fold_page_trylock(zhdr)) { 13551f862989SVitaly Wool unlock_page(page); 13561f862989SVitaly Wool return -EAGAIN; 13571f862989SVitaly Wool } 13581f862989SVitaly Wool if (zhdr->mapped_count != 0) { 13591f862989SVitaly Wool z3fold_page_unlock(zhdr); 13601f862989SVitaly Wool unlock_page(page); 13611f862989SVitaly Wool return -EBUSY; 13621f862989SVitaly Wool } 13631f862989SVitaly Wool new_zhdr = page_address(newpage); 13641f862989SVitaly Wool memcpy(new_zhdr, zhdr, PAGE_SIZE); 13651f862989SVitaly Wool newpage->private = page->private; 13661f862989SVitaly Wool page->private = 0; 13671f862989SVitaly Wool z3fold_page_unlock(zhdr); 13681f862989SVitaly Wool spin_lock_init(&new_zhdr->page_lock); 13691f862989SVitaly Wool new_mapping = page_mapping(page); 13701f862989SVitaly Wool __ClearPageMovable(page); 13711f862989SVitaly Wool ClearPagePrivate(page); 13721f862989SVitaly Wool 13731f862989SVitaly Wool get_page(newpage); 13741f862989SVitaly Wool z3fold_page_lock(new_zhdr); 13751f862989SVitaly Wool if (new_zhdr->first_chunks) 13761f862989SVitaly Wool encode_handle(new_zhdr, FIRST); 13771f862989SVitaly Wool if (new_zhdr->last_chunks) 13781f862989SVitaly Wool encode_handle(new_zhdr, LAST); 13791f862989SVitaly Wool if (new_zhdr->middle_chunks) 13801f862989SVitaly Wool encode_handle(new_zhdr, MIDDLE); 13811f862989SVitaly Wool set_bit(NEEDS_COMPACTING, &newpage->private); 13821f862989SVitaly Wool new_zhdr->cpu = smp_processor_id(); 13831f862989SVitaly Wool spin_lock(&pool->lock); 13841f862989SVitaly Wool list_add(&newpage->lru, &pool->lru); 13851f862989SVitaly Wool spin_unlock(&pool->lock); 13861f862989SVitaly Wool __SetPageMovable(newpage, new_mapping); 13871f862989SVitaly Wool z3fold_page_unlock(new_zhdr); 13881f862989SVitaly Wool 13891f862989SVitaly Wool queue_work_on(new_zhdr->cpu, pool->compact_wq, &new_zhdr->work); 13901f862989SVitaly Wool 13911f862989SVitaly Wool page_mapcount_reset(page); 13921f862989SVitaly Wool unlock_page(page); 13931f862989SVitaly Wool put_page(page); 13941f862989SVitaly Wool return 0; 13951f862989SVitaly Wool } 13961f862989SVitaly Wool 13971f862989SVitaly Wool static void z3fold_page_putback(struct page *page) 13981f862989SVitaly Wool { 13991f862989SVitaly Wool struct z3fold_header *zhdr; 14001f862989SVitaly Wool struct z3fold_pool *pool; 14011f862989SVitaly Wool 14021f862989SVitaly Wool zhdr = page_address(page); 14031f862989SVitaly Wool pool = zhdr_to_pool(zhdr); 14041f862989SVitaly Wool 14051f862989SVitaly Wool z3fold_page_lock(zhdr); 14061f862989SVitaly Wool if (!list_empty(&zhdr->buddy)) 14071f862989SVitaly Wool list_del_init(&zhdr->buddy); 14081f862989SVitaly Wool INIT_LIST_HEAD(&page->lru); 14091f862989SVitaly Wool if (kref_put(&zhdr->refcount, release_z3fold_page_locked)) { 14101f862989SVitaly Wool atomic64_dec(&pool->pages_nr); 14111f862989SVitaly Wool return; 14121f862989SVitaly Wool } 14131f862989SVitaly Wool spin_lock(&pool->lock); 14141f862989SVitaly Wool list_add(&page->lru, &pool->lru); 14151f862989SVitaly Wool spin_unlock(&pool->lock); 14161f862989SVitaly Wool z3fold_page_unlock(zhdr); 14171f862989SVitaly Wool } 14181f862989SVitaly Wool 14191f862989SVitaly Wool static const struct address_space_operations z3fold_aops = { 14201f862989SVitaly Wool .isolate_page = z3fold_page_isolate, 14211f862989SVitaly Wool .migratepage = z3fold_page_migrate, 14221f862989SVitaly Wool .putback_page = z3fold_page_putback, 14231f862989SVitaly Wool }; 14241f862989SVitaly Wool 14259a001fc1SVitaly Wool /***************** 14269a001fc1SVitaly Wool * zpool 14279a001fc1SVitaly Wool ****************/ 14289a001fc1SVitaly Wool 14299a001fc1SVitaly Wool static int z3fold_zpool_evict(struct z3fold_pool *pool, unsigned long handle) 14309a001fc1SVitaly Wool { 14319a001fc1SVitaly Wool if (pool->zpool && pool->zpool_ops && pool->zpool_ops->evict) 14329a001fc1SVitaly Wool return pool->zpool_ops->evict(pool->zpool, handle); 14339a001fc1SVitaly Wool else 14349a001fc1SVitaly Wool return -ENOENT; 14359a001fc1SVitaly Wool } 14369a001fc1SVitaly Wool 14379a001fc1SVitaly Wool static const struct z3fold_ops z3fold_zpool_ops = { 14389a001fc1SVitaly Wool .evict = z3fold_zpool_evict 14399a001fc1SVitaly Wool }; 14409a001fc1SVitaly Wool 14419a001fc1SVitaly Wool static void *z3fold_zpool_create(const char *name, gfp_t gfp, 14429a001fc1SVitaly Wool const struct zpool_ops *zpool_ops, 14439a001fc1SVitaly Wool struct zpool *zpool) 14449a001fc1SVitaly Wool { 14459a001fc1SVitaly Wool struct z3fold_pool *pool; 14469a001fc1SVitaly Wool 1447d30561c5SVitaly Wool pool = z3fold_create_pool(name, gfp, 1448d30561c5SVitaly Wool zpool_ops ? &z3fold_zpool_ops : NULL); 14499a001fc1SVitaly Wool if (pool) { 14509a001fc1SVitaly Wool pool->zpool = zpool; 14519a001fc1SVitaly Wool pool->zpool_ops = zpool_ops; 14529a001fc1SVitaly Wool } 14539a001fc1SVitaly Wool return pool; 14549a001fc1SVitaly Wool } 14559a001fc1SVitaly Wool 14569a001fc1SVitaly Wool static void z3fold_zpool_destroy(void *pool) 14579a001fc1SVitaly Wool { 14589a001fc1SVitaly Wool z3fold_destroy_pool(pool); 14599a001fc1SVitaly Wool } 14609a001fc1SVitaly Wool 14619a001fc1SVitaly Wool static int z3fold_zpool_malloc(void *pool, size_t size, gfp_t gfp, 14629a001fc1SVitaly Wool unsigned long *handle) 14639a001fc1SVitaly Wool { 14649a001fc1SVitaly Wool return z3fold_alloc(pool, size, gfp, handle); 14659a001fc1SVitaly Wool } 14669a001fc1SVitaly Wool static void z3fold_zpool_free(void *pool, unsigned long handle) 14679a001fc1SVitaly Wool { 14689a001fc1SVitaly Wool z3fold_free(pool, handle); 14699a001fc1SVitaly Wool } 14709a001fc1SVitaly Wool 14719a001fc1SVitaly Wool static int z3fold_zpool_shrink(void *pool, unsigned int pages, 14729a001fc1SVitaly Wool unsigned int *reclaimed) 14739a001fc1SVitaly Wool { 14749a001fc1SVitaly Wool unsigned int total = 0; 14759a001fc1SVitaly Wool int ret = -EINVAL; 14769a001fc1SVitaly Wool 14779a001fc1SVitaly Wool while (total < pages) { 14789a001fc1SVitaly Wool ret = z3fold_reclaim_page(pool, 8); 14799a001fc1SVitaly Wool if (ret < 0) 14809a001fc1SVitaly Wool break; 14819a001fc1SVitaly Wool total++; 14829a001fc1SVitaly Wool } 14839a001fc1SVitaly Wool 14849a001fc1SVitaly Wool if (reclaimed) 14859a001fc1SVitaly Wool *reclaimed = total; 14869a001fc1SVitaly Wool 14879a001fc1SVitaly Wool return ret; 14889a001fc1SVitaly Wool } 14899a001fc1SVitaly Wool 14909a001fc1SVitaly Wool static void *z3fold_zpool_map(void *pool, unsigned long handle, 14919a001fc1SVitaly Wool enum zpool_mapmode mm) 14929a001fc1SVitaly Wool { 14939a001fc1SVitaly Wool return z3fold_map(pool, handle); 14949a001fc1SVitaly Wool } 14959a001fc1SVitaly Wool static void z3fold_zpool_unmap(void *pool, unsigned long handle) 14969a001fc1SVitaly Wool { 14979a001fc1SVitaly Wool z3fold_unmap(pool, handle); 14989a001fc1SVitaly Wool } 14999a001fc1SVitaly Wool 15009a001fc1SVitaly Wool static u64 z3fold_zpool_total_size(void *pool) 15019a001fc1SVitaly Wool { 15029a001fc1SVitaly Wool return z3fold_get_pool_size(pool) * PAGE_SIZE; 15039a001fc1SVitaly Wool } 15049a001fc1SVitaly Wool 15059a001fc1SVitaly Wool static struct zpool_driver z3fold_zpool_driver = { 15069a001fc1SVitaly Wool .type = "z3fold", 15079a001fc1SVitaly Wool .owner = THIS_MODULE, 15089a001fc1SVitaly Wool .create = z3fold_zpool_create, 15099a001fc1SVitaly Wool .destroy = z3fold_zpool_destroy, 15109a001fc1SVitaly Wool .malloc = z3fold_zpool_malloc, 15119a001fc1SVitaly Wool .free = z3fold_zpool_free, 15129a001fc1SVitaly Wool .shrink = z3fold_zpool_shrink, 15139a001fc1SVitaly Wool .map = z3fold_zpool_map, 15149a001fc1SVitaly Wool .unmap = z3fold_zpool_unmap, 15159a001fc1SVitaly Wool .total_size = z3fold_zpool_total_size, 15169a001fc1SVitaly Wool }; 15179a001fc1SVitaly Wool 15189a001fc1SVitaly Wool MODULE_ALIAS("zpool-z3fold"); 15199a001fc1SVitaly Wool 15209a001fc1SVitaly Wool static int __init init_z3fold(void) 15219a001fc1SVitaly Wool { 15221f862989SVitaly Wool int ret; 15231f862989SVitaly Wool 1524ede93213SVitaly Wool /* Make sure the z3fold header is not larger than the page size */ 1525ede93213SVitaly Wool BUILD_BUG_ON(ZHDR_SIZE_ALIGNED > PAGE_SIZE); 15261f862989SVitaly Wool ret = z3fold_mount(); 15271f862989SVitaly Wool if (ret) 15281f862989SVitaly Wool return ret; 15291f862989SVitaly Wool 15309a001fc1SVitaly Wool zpool_register_driver(&z3fold_zpool_driver); 15319a001fc1SVitaly Wool 15329a001fc1SVitaly Wool return 0; 15339a001fc1SVitaly Wool } 15349a001fc1SVitaly Wool 15359a001fc1SVitaly Wool static void __exit exit_z3fold(void) 15369a001fc1SVitaly Wool { 15371f862989SVitaly Wool z3fold_unmount(); 15389a001fc1SVitaly Wool zpool_unregister_driver(&z3fold_zpool_driver); 15399a001fc1SVitaly Wool } 15409a001fc1SVitaly Wool 15419a001fc1SVitaly Wool module_init(init_z3fold); 15429a001fc1SVitaly Wool module_exit(exit_z3fold); 15439a001fc1SVitaly Wool 15449a001fc1SVitaly Wool MODULE_LICENSE("GPL"); 15459a001fc1SVitaly Wool MODULE_AUTHOR("Vitaly Wool <vitalywool@gmail.com>"); 15469a001fc1SVitaly Wool MODULE_DESCRIPTION("3-Fold Allocator for Compressed Pages"); 1547