/* * Copyright © 2006-2009, Intel Corporation. * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc., 59 Temple * Place - Suite 330, Boston, MA 02111-1307 USA. * * Author: Anil S Keshavamurthy */ #include #include #include #include #include #include /* The anchor node sits above the top of the usable address space */ #define IOVA_ANCHOR ~0UL static bool iova_rcache_insert(struct iova_domain *iovad, unsigned long pfn, unsigned long size); static unsigned long iova_rcache_get(struct iova_domain *iovad, unsigned long size, unsigned long limit_pfn); static void init_iova_rcaches(struct iova_domain *iovad); static void free_iova_rcaches(struct iova_domain *iovad); static void fq_destroy_all_entries(struct iova_domain *iovad); static void fq_flush_timeout(unsigned long data); void init_iova_domain(struct iova_domain *iovad, unsigned long granule, unsigned long start_pfn) { /* * IOVA granularity will normally be equal to the smallest * supported IOMMU page size; both *must* be capable of * representing individual CPU pages exactly. */ BUG_ON((granule > PAGE_SIZE) || !is_power_of_2(granule)); spin_lock_init(&iovad->iova_rbtree_lock); iovad->rbroot = RB_ROOT; iovad->cached_node = &iovad->anchor.node; iovad->cached32_node = &iovad->anchor.node; iovad->granule = granule; iovad->start_pfn = start_pfn; iovad->dma_32bit_pfn = 1UL << (32 - iova_shift(iovad)); iovad->flush_cb = NULL; iovad->fq = NULL; iovad->anchor.pfn_lo = iovad->anchor.pfn_hi = IOVA_ANCHOR; rb_link_node(&iovad->anchor.node, NULL, &iovad->rbroot.rb_node); rb_insert_color(&iovad->anchor.node, &iovad->rbroot); init_iova_rcaches(iovad); } EXPORT_SYMBOL_GPL(init_iova_domain); static void free_iova_flush_queue(struct iova_domain *iovad) { if (!iovad->fq) return; if (timer_pending(&iovad->fq_timer)) del_timer(&iovad->fq_timer); fq_destroy_all_entries(iovad); free_percpu(iovad->fq); iovad->fq = NULL; iovad->flush_cb = NULL; iovad->entry_dtor = NULL; } int init_iova_flush_queue(struct iova_domain *iovad, iova_flush_cb flush_cb, iova_entry_dtor entry_dtor) { int cpu; atomic64_set(&iovad->fq_flush_start_cnt, 0); atomic64_set(&iovad->fq_flush_finish_cnt, 0); iovad->fq = alloc_percpu(struct iova_fq); if (!iovad->fq) return -ENOMEM; iovad->flush_cb = flush_cb; iovad->entry_dtor = entry_dtor; for_each_possible_cpu(cpu) { struct iova_fq *fq; fq = per_cpu_ptr(iovad->fq, cpu); fq->head = 0; fq->tail = 0; spin_lock_init(&fq->lock); } setup_timer(&iovad->fq_timer, fq_flush_timeout, (unsigned long)iovad); atomic_set(&iovad->fq_timer_on, 0); return 0; } EXPORT_SYMBOL_GPL(init_iova_flush_queue); static struct rb_node * __get_cached_rbnode(struct iova_domain *iovad, unsigned long limit_pfn) { if (limit_pfn <= iovad->dma_32bit_pfn) return iovad->cached32_node; return iovad->cached_node; } static void __cached_rbnode_insert_update(struct iova_domain *iovad, struct iova *new) { if (new->pfn_hi < iovad->dma_32bit_pfn) iovad->cached32_node = &new->node; else iovad->cached_node = &new->node; } static void __cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free) { struct iova *cached_iova; cached_iova = rb_entry(iovad->cached32_node, struct iova, node); if (free->pfn_hi < iovad->dma_32bit_pfn && free->pfn_lo >= cached_iova->pfn_lo) iovad->cached32_node = rb_next(&free->node); cached_iova = rb_entry(iovad->cached_node, struct iova, node); if (free->pfn_lo >= cached_iova->pfn_lo) iovad->cached_node = rb_next(&free->node); } /* Insert the iova into domain rbtree by holding writer lock */ static void iova_insert_rbtree(struct rb_root *root, struct iova *iova, struct rb_node *start) { struct rb_node **new, *parent = NULL; new = (start) ? &start : &(root->rb_node); /* Figure out where to put new node */ while (*new) { struct iova *this = rb_entry(*new, struct iova, node); parent = *new; if (iova->pfn_lo < this->pfn_lo) new = &((*new)->rb_left); else if (iova->pfn_lo > this->pfn_lo) new = &((*new)->rb_right); else { WARN_ON(1); /* this should not happen */ return; } } /* Add new node and rebalance tree. */ rb_link_node(&iova->node, parent, new); rb_insert_color(&iova->node, root); } static int __alloc_and_insert_iova_range(struct iova_domain *iovad, unsigned long size, unsigned long limit_pfn, struct iova *new, bool size_aligned) { struct rb_node *curr, *prev; struct iova *curr_iova; unsigned long flags; unsigned long new_pfn; unsigned long align_mask = ~0UL; if (size_aligned) align_mask <<= fls_long(size - 1); /* Walk the tree backwards */ spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); curr = __get_cached_rbnode(iovad, limit_pfn); curr_iova = rb_entry(curr, struct iova, node); do { limit_pfn = min(limit_pfn, curr_iova->pfn_lo); new_pfn = (limit_pfn - size) & align_mask; prev = curr; curr = rb_prev(curr); curr_iova = rb_entry(curr, struct iova, node); } while (curr && new_pfn <= curr_iova->pfn_hi); if (limit_pfn < size || new_pfn < iovad->start_pfn) { spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); return -ENOMEM; } /* pfn_lo will point to size aligned address if size_aligned is set */ new->pfn_lo = new_pfn; new->pfn_hi = new->pfn_lo + size - 1; /* If we have 'prev', it's a valid place to start the insertion. */ iova_insert_rbtree(&iovad->rbroot, new, prev); __cached_rbnode_insert_update(iovad, new); spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); return 0; } static struct kmem_cache *iova_cache; static unsigned int iova_cache_users; static DEFINE_MUTEX(iova_cache_mutex); struct iova *alloc_iova_mem(void) { return kmem_cache_alloc(iova_cache, GFP_ATOMIC); } EXPORT_SYMBOL(alloc_iova_mem); void free_iova_mem(struct iova *iova) { if (iova->pfn_lo != IOVA_ANCHOR) kmem_cache_free(iova_cache, iova); } EXPORT_SYMBOL(free_iova_mem); int iova_cache_get(void) { mutex_lock(&iova_cache_mutex); if (!iova_cache_users) { iova_cache = kmem_cache_create( "iommu_iova", sizeof(struct iova), 0, SLAB_HWCACHE_ALIGN, NULL); if (!iova_cache) { mutex_unlock(&iova_cache_mutex); printk(KERN_ERR "Couldn't create iova cache\n"); return -ENOMEM; } } iova_cache_users++; mutex_unlock(&iova_cache_mutex); return 0; } EXPORT_SYMBOL_GPL(iova_cache_get); void iova_cache_put(void) { mutex_lock(&iova_cache_mutex); if (WARN_ON(!iova_cache_users)) { mutex_unlock(&iova_cache_mutex); return; } iova_cache_users--; if (!iova_cache_users) kmem_cache_destroy(iova_cache); mutex_unlock(&iova_cache_mutex); } EXPORT_SYMBOL_GPL(iova_cache_put); /** * alloc_iova - allocates an iova * @iovad: - iova domain in question * @size: - size of page frames to allocate * @limit_pfn: - max limit address * @size_aligned: - set if size_aligned address range is required * This function allocates an iova in the range iovad->start_pfn to limit_pfn, * searching top-down from limit_pfn to iovad->start_pfn. If the size_aligned * flag is set then the allocated address iova->pfn_lo will be naturally * aligned on roundup_power_of_two(size). */ struct iova * alloc_iova(struct iova_domain *iovad, unsigned long size, unsigned long limit_pfn, bool size_aligned) { struct iova *new_iova; int ret; new_iova = alloc_iova_mem(); if (!new_iova) return NULL; ret = __alloc_and_insert_iova_range(iovad, size, limit_pfn + 1, new_iova, size_aligned); if (ret) { free_iova_mem(new_iova); return NULL; } return new_iova; } EXPORT_SYMBOL_GPL(alloc_iova); static struct iova * private_find_iova(struct iova_domain *iovad, unsigned long pfn) { struct rb_node *node = iovad->rbroot.rb_node; assert_spin_locked(&iovad->iova_rbtree_lock); while (node) { struct iova *iova = rb_entry(node, struct iova, node); if (pfn < iova->pfn_lo) node = node->rb_left; else if (pfn > iova->pfn_hi) node = node->rb_right; else return iova; /* pfn falls within iova's range */ } return NULL; } static void private_free_iova(struct iova_domain *iovad, struct iova *iova) { assert_spin_locked(&iovad->iova_rbtree_lock); __cached_rbnode_delete_update(iovad, iova); rb_erase(&iova->node, &iovad->rbroot); free_iova_mem(iova); } /** * find_iova - finds an iova for a given pfn * @iovad: - iova domain in question. * @pfn: - page frame number * This function finds and returns an iova belonging to the * given doamin which matches the given pfn. */ struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn) { unsigned long flags; struct iova *iova; /* Take the lock so that no other thread is manipulating the rbtree */ spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); iova = private_find_iova(iovad, pfn); spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); return iova; } EXPORT_SYMBOL_GPL(find_iova); /** * __free_iova - frees the given iova * @iovad: iova domain in question. * @iova: iova in question. * Frees the given iova belonging to the giving domain */ void __free_iova(struct iova_domain *iovad, struct iova *iova) { unsigned long flags; spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); private_free_iova(iovad, iova); spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); } EXPORT_SYMBOL_GPL(__free_iova); /** * free_iova - finds and frees the iova for a given pfn * @iovad: - iova domain in question. * @pfn: - pfn that is allocated previously * This functions finds an iova for a given pfn and then * frees the iova from that domain. */ void free_iova(struct iova_domain *iovad, unsigned long pfn) { struct iova *iova = find_iova(iovad, pfn); if (iova) __free_iova(iovad, iova); } EXPORT_SYMBOL_GPL(free_iova); /** * alloc_iova_fast - allocates an iova from rcache * @iovad: - iova domain in question * @size: - size of page frames to allocate * @limit_pfn: - max limit address * This function tries to satisfy an iova allocation from the rcache, * and falls back to regular allocation on failure. */ unsigned long alloc_iova_fast(struct iova_domain *iovad, unsigned long size, unsigned long limit_pfn) { bool flushed_rcache = false; unsigned long iova_pfn; struct iova *new_iova; iova_pfn = iova_rcache_get(iovad, size, limit_pfn); if (iova_pfn) return iova_pfn; retry: new_iova = alloc_iova(iovad, size, limit_pfn, true); if (!new_iova) { unsigned int cpu; if (flushed_rcache) return 0; /* Try replenishing IOVAs by flushing rcache. */ flushed_rcache = true; for_each_online_cpu(cpu) free_cpu_cached_iovas(cpu, iovad); goto retry; } return new_iova->pfn_lo; } EXPORT_SYMBOL_GPL(alloc_iova_fast); /** * free_iova_fast - free iova pfn range into rcache * @iovad: - iova domain in question. * @pfn: - pfn that is allocated previously * @size: - # of pages in range * This functions frees an iova range by trying to put it into the rcache, * falling back to regular iova deallocation via free_iova() if this fails. */ void free_iova_fast(struct iova_domain *iovad, unsigned long pfn, unsigned long size) { if (iova_rcache_insert(iovad, pfn, size)) return; free_iova(iovad, pfn); } EXPORT_SYMBOL_GPL(free_iova_fast); #define fq_ring_for_each(i, fq) \ for ((i) = (fq)->head; (i) != (fq)->tail; (i) = ((i) + 1) % IOVA_FQ_SIZE) static inline bool fq_full(struct iova_fq *fq) { assert_spin_locked(&fq->lock); return (((fq->tail + 1) % IOVA_FQ_SIZE) == fq->head); } static inline unsigned fq_ring_add(struct iova_fq *fq) { unsigned idx = fq->tail; assert_spin_locked(&fq->lock); fq->tail = (idx + 1) % IOVA_FQ_SIZE; return idx; } static void fq_ring_free(struct iova_domain *iovad, struct iova_fq *fq) { u64 counter = atomic64_read(&iovad->fq_flush_finish_cnt); unsigned idx; assert_spin_locked(&fq->lock); fq_ring_for_each(idx, fq) { if (fq->entries[idx].counter >= counter) break; if (iovad->entry_dtor) iovad->entry_dtor(fq->entries[idx].data); free_iova_fast(iovad, fq->entries[idx].iova_pfn, fq->entries[idx].pages); fq->head = (fq->head + 1) % IOVA_FQ_SIZE; } } static void iova_domain_flush(struct iova_domain *iovad) { atomic64_inc(&iovad->fq_flush_start_cnt); iovad->flush_cb(iovad); atomic64_inc(&iovad->fq_flush_finish_cnt); } static void fq_destroy_all_entries(struct iova_domain *iovad) { int cpu; /* * This code runs when the iova_domain is being detroyed, so don't * bother to free iovas, just call the entry_dtor on all remaining * entries. */ if (!iovad->entry_dtor) return; for_each_possible_cpu(cpu) { struct iova_fq *fq = per_cpu_ptr(iovad->fq, cpu); int idx; fq_ring_for_each(idx, fq) iovad->entry_dtor(fq->entries[idx].data); } } static void fq_flush_timeout(unsigned long data) { struct iova_domain *iovad = (struct iova_domain *)data; int cpu; atomic_set(&iovad->fq_timer_on, 0); iova_domain_flush(iovad); for_each_possible_cpu(cpu) { unsigned long flags; struct iova_fq *fq; fq = per_cpu_ptr(iovad->fq, cpu); spin_lock_irqsave(&fq->lock, flags); fq_ring_free(iovad, fq); spin_unlock_irqrestore(&fq->lock, flags); } } void queue_iova(struct iova_domain *iovad, unsigned long pfn, unsigned long pages, unsigned long data) { struct iova_fq *fq = get_cpu_ptr(iovad->fq); unsigned long flags; unsigned idx; spin_lock_irqsave(&fq->lock, flags); /* * First remove all entries from the flush queue that have already been * flushed out on another CPU. This makes the fq_full() check below less * likely to be true. */ fq_ring_free(iovad, fq); if (fq_full(fq)) { iova_domain_flush(iovad); fq_ring_free(iovad, fq); } idx = fq_ring_add(fq); fq->entries[idx].iova_pfn = pfn; fq->entries[idx].pages = pages; fq->entries[idx].data = data; fq->entries[idx].counter = atomic64_read(&iovad->fq_flush_start_cnt); spin_unlock_irqrestore(&fq->lock, flags); if (atomic_cmpxchg(&iovad->fq_timer_on, 0, 1) == 0) mod_timer(&iovad->fq_timer, jiffies + msecs_to_jiffies(IOVA_FQ_TIMEOUT)); put_cpu_ptr(iovad->fq); } EXPORT_SYMBOL_GPL(queue_iova); /** * put_iova_domain - destroys the iova doamin * @iovad: - iova domain in question. * All the iova's in that domain are destroyed. */ void put_iova_domain(struct iova_domain *iovad) { struct rb_node *node; unsigned long flags; free_iova_flush_queue(iovad); free_iova_rcaches(iovad); spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); node = rb_first(&iovad->rbroot); while (node) { struct iova *iova = rb_entry(node, struct iova, node); rb_erase(node, &iovad->rbroot); free_iova_mem(iova); node = rb_first(&iovad->rbroot); } spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); } EXPORT_SYMBOL_GPL(put_iova_domain); static int __is_range_overlap(struct rb_node *node, unsigned long pfn_lo, unsigned long pfn_hi) { struct iova *iova = rb_entry(node, struct iova, node); if ((pfn_lo <= iova->pfn_hi) && (pfn_hi >= iova->pfn_lo)) return 1; return 0; } static inline struct iova * alloc_and_init_iova(unsigned long pfn_lo, unsigned long pfn_hi) { struct iova *iova; iova = alloc_iova_mem(); if (iova) { iova->pfn_lo = pfn_lo; iova->pfn_hi = pfn_hi; } return iova; } static struct iova * __insert_new_range(struct iova_domain *iovad, unsigned long pfn_lo, unsigned long pfn_hi) { struct iova *iova; iova = alloc_and_init_iova(pfn_lo, pfn_hi); if (iova) iova_insert_rbtree(&iovad->rbroot, iova, NULL); return iova; } static void __adjust_overlap_range(struct iova *iova, unsigned long *pfn_lo, unsigned long *pfn_hi) { if (*pfn_lo < iova->pfn_lo) iova->pfn_lo = *pfn_lo; if (*pfn_hi > iova->pfn_hi) *pfn_lo = iova->pfn_hi + 1; } /** * reserve_iova - reserves an iova in the given range * @iovad: - iova domain pointer * @pfn_lo: - lower page frame address * @pfn_hi:- higher pfn adderss * This function allocates reserves the address range from pfn_lo to pfn_hi so * that this address is not dished out as part of alloc_iova. */ struct iova * reserve_iova(struct iova_domain *iovad, unsigned long pfn_lo, unsigned long pfn_hi) { struct rb_node *node; unsigned long flags; struct iova *iova; unsigned int overlap = 0; /* Don't allow nonsensical pfns */ if (WARN_ON((pfn_hi | pfn_lo) > (ULLONG_MAX >> iova_shift(iovad)))) return NULL; spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); for (node = rb_first(&iovad->rbroot); node; node = rb_next(node)) { if (__is_range_overlap(node, pfn_lo, pfn_hi)) { iova = rb_entry(node, struct iova, node); __adjust_overlap_range(iova, &pfn_lo, &pfn_hi); if ((pfn_lo >= iova->pfn_lo) && (pfn_hi <= iova->pfn_hi)) goto finish; overlap = 1; } else if (overlap) break; } /* We are here either because this is the first reserver node * or need to insert remaining non overlap addr range */ iova = __insert_new_range(iovad, pfn_lo, pfn_hi); finish: spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); return iova; } EXPORT_SYMBOL_GPL(reserve_iova); /** * copy_reserved_iova - copies the reserved between domains * @from: - source doamin from where to copy * @to: - destination domin where to copy * This function copies reserved iova's from one doamin to * other. */ void copy_reserved_iova(struct iova_domain *from, struct iova_domain *to) { unsigned long flags; struct rb_node *node; spin_lock_irqsave(&from->iova_rbtree_lock, flags); for (node = rb_first(&from->rbroot); node; node = rb_next(node)) { struct iova *iova = rb_entry(node, struct iova, node); struct iova *new_iova; new_iova = reserve_iova(to, iova->pfn_lo, iova->pfn_hi); if (!new_iova) printk(KERN_ERR "Reserve iova range %lx@%lx failed\n", iova->pfn_lo, iova->pfn_lo); } spin_unlock_irqrestore(&from->iova_rbtree_lock, flags); } EXPORT_SYMBOL_GPL(copy_reserved_iova); struct iova * split_and_remove_iova(struct iova_domain *iovad, struct iova *iova, unsigned long pfn_lo, unsigned long pfn_hi) { unsigned long flags; struct iova *prev = NULL, *next = NULL; spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); if (iova->pfn_lo < pfn_lo) { prev = alloc_and_init_iova(iova->pfn_lo, pfn_lo - 1); if (prev == NULL) goto error; } if (iova->pfn_hi > pfn_hi) { next = alloc_and_init_iova(pfn_hi + 1, iova->pfn_hi); if (next == NULL) goto error; } __cached_rbnode_delete_update(iovad, iova); rb_erase(&iova->node, &iovad->rbroot); if (prev) { iova_insert_rbtree(&iovad->rbroot, prev, NULL); iova->pfn_lo = pfn_lo; } if (next) { iova_insert_rbtree(&iovad->rbroot, next, NULL); iova->pfn_hi = pfn_hi; } spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); return iova; error: spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); if (prev) free_iova_mem(prev); return NULL; } /* * Magazine caches for IOVA ranges. For an introduction to magazines, * see the USENIX 2001 paper "Magazines and Vmem: Extending the Slab * Allocator to Many CPUs and Arbitrary Resources" by Bonwick and Adams. * For simplicity, we use a static magazine size and don't implement the * dynamic size tuning described in the paper. */ #define IOVA_MAG_SIZE 128 struct iova_magazine { unsigned long size; unsigned long pfns[IOVA_MAG_SIZE]; }; struct iova_cpu_rcache { spinlock_t lock; struct iova_magazine *loaded; struct iova_magazine *prev; }; static struct iova_magazine *iova_magazine_alloc(gfp_t flags) { return kzalloc(sizeof(struct iova_magazine), flags); } static void iova_magazine_free(struct iova_magazine *mag) { kfree(mag); } static void iova_magazine_free_pfns(struct iova_magazine *mag, struct iova_domain *iovad) { unsigned long flags; int i; if (!mag) return; spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); for (i = 0 ; i < mag->size; ++i) { struct iova *iova = private_find_iova(iovad, mag->pfns[i]); BUG_ON(!iova); private_free_iova(iovad, iova); } spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); mag->size = 0; } static bool iova_magazine_full(struct iova_magazine *mag) { return (mag && mag->size == IOVA_MAG_SIZE); } static bool iova_magazine_empty(struct iova_magazine *mag) { return (!mag || mag->size == 0); } static unsigned long iova_magazine_pop(struct iova_magazine *mag, unsigned long limit_pfn) { BUG_ON(iova_magazine_empty(mag)); if (mag->pfns[mag->size - 1] >= limit_pfn) return 0; return mag->pfns[--mag->size]; } static void iova_magazine_push(struct iova_magazine *mag, unsigned long pfn) { BUG_ON(iova_magazine_full(mag)); mag->pfns[mag->size++] = pfn; } static void init_iova_rcaches(struct iova_domain *iovad) { struct iova_cpu_rcache *cpu_rcache; struct iova_rcache *rcache; unsigned int cpu; int i; for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) { rcache = &iovad->rcaches[i]; spin_lock_init(&rcache->lock); rcache->depot_size = 0; rcache->cpu_rcaches = __alloc_percpu(sizeof(*cpu_rcache), cache_line_size()); if (WARN_ON(!rcache->cpu_rcaches)) continue; for_each_possible_cpu(cpu) { cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu); spin_lock_init(&cpu_rcache->lock); cpu_rcache->loaded = iova_magazine_alloc(GFP_KERNEL); cpu_rcache->prev = iova_magazine_alloc(GFP_KERNEL); } } } /* * Try inserting IOVA range starting with 'iova_pfn' into 'rcache', and * return true on success. Can fail if rcache is full and we can't free * space, and free_iova() (our only caller) will then return the IOVA * range to the rbtree instead. */ static bool __iova_rcache_insert(struct iova_domain *iovad, struct iova_rcache *rcache, unsigned long iova_pfn) { struct iova_magazine *mag_to_free = NULL; struct iova_cpu_rcache *cpu_rcache; bool can_insert = false; unsigned long flags; cpu_rcache = raw_cpu_ptr(rcache->cpu_rcaches); spin_lock_irqsave(&cpu_rcache->lock, flags); if (!iova_magazine_full(cpu_rcache->loaded)) { can_insert = true; } else if (!iova_magazine_full(cpu_rcache->prev)) { swap(cpu_rcache->prev, cpu_rcache->loaded); can_insert = true; } else { struct iova_magazine *new_mag = iova_magazine_alloc(GFP_ATOMIC); if (new_mag) { spin_lock(&rcache->lock); if (rcache->depot_size < MAX_GLOBAL_MAGS) { rcache->depot[rcache->depot_size++] = cpu_rcache->loaded; } else { mag_to_free = cpu_rcache->loaded; } spin_unlock(&rcache->lock); cpu_rcache->loaded = new_mag; can_insert = true; } } if (can_insert) iova_magazine_push(cpu_rcache->loaded, iova_pfn); spin_unlock_irqrestore(&cpu_rcache->lock, flags); if (mag_to_free) { iova_magazine_free_pfns(mag_to_free, iovad); iova_magazine_free(mag_to_free); } return can_insert; } static bool iova_rcache_insert(struct iova_domain *iovad, unsigned long pfn, unsigned long size) { unsigned int log_size = order_base_2(size); if (log_size >= IOVA_RANGE_CACHE_MAX_SIZE) return false; return __iova_rcache_insert(iovad, &iovad->rcaches[log_size], pfn); } /* * Caller wants to allocate a new IOVA range from 'rcache'. If we can * satisfy the request, return a matching non-NULL range and remove * it from the 'rcache'. */ static unsigned long __iova_rcache_get(struct iova_rcache *rcache, unsigned long limit_pfn) { struct iova_cpu_rcache *cpu_rcache; unsigned long iova_pfn = 0; bool has_pfn = false; unsigned long flags; cpu_rcache = raw_cpu_ptr(rcache->cpu_rcaches); spin_lock_irqsave(&cpu_rcache->lock, flags); if (!iova_magazine_empty(cpu_rcache->loaded)) { has_pfn = true; } else if (!iova_magazine_empty(cpu_rcache->prev)) { swap(cpu_rcache->prev, cpu_rcache->loaded); has_pfn = true; } else { spin_lock(&rcache->lock); if (rcache->depot_size > 0) { iova_magazine_free(cpu_rcache->loaded); cpu_rcache->loaded = rcache->depot[--rcache->depot_size]; has_pfn = true; } spin_unlock(&rcache->lock); } if (has_pfn) iova_pfn = iova_magazine_pop(cpu_rcache->loaded, limit_pfn); spin_unlock_irqrestore(&cpu_rcache->lock, flags); return iova_pfn; } /* * Try to satisfy IOVA allocation range from rcache. Fail if requested * size is too big or the DMA limit we are given isn't satisfied by the * top element in the magazine. */ static unsigned long iova_rcache_get(struct iova_domain *iovad, unsigned long size, unsigned long limit_pfn) { unsigned int log_size = order_base_2(size); if (log_size >= IOVA_RANGE_CACHE_MAX_SIZE) return 0; return __iova_rcache_get(&iovad->rcaches[log_size], limit_pfn); } /* * Free a cpu's rcache. */ static void free_cpu_iova_rcache(unsigned int cpu, struct iova_domain *iovad, struct iova_rcache *rcache) { struct iova_cpu_rcache *cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu); unsigned long flags; spin_lock_irqsave(&cpu_rcache->lock, flags); iova_magazine_free_pfns(cpu_rcache->loaded, iovad); iova_magazine_free(cpu_rcache->loaded); iova_magazine_free_pfns(cpu_rcache->prev, iovad); iova_magazine_free(cpu_rcache->prev); spin_unlock_irqrestore(&cpu_rcache->lock, flags); } /* * free rcache data structures. */ static void free_iova_rcaches(struct iova_domain *iovad) { struct iova_rcache *rcache; unsigned long flags; unsigned int cpu; int i, j; for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) { rcache = &iovad->rcaches[i]; for_each_possible_cpu(cpu) free_cpu_iova_rcache(cpu, iovad, rcache); spin_lock_irqsave(&rcache->lock, flags); free_percpu(rcache->cpu_rcaches); for (j = 0; j < rcache->depot_size; ++j) { iova_magazine_free_pfns(rcache->depot[j], iovad); iova_magazine_free(rcache->depot[j]); } spin_unlock_irqrestore(&rcache->lock, flags); } } /* * free all the IOVA ranges cached by a cpu (used when cpu is unplugged) */ void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad) { struct iova_cpu_rcache *cpu_rcache; struct iova_rcache *rcache; unsigned long flags; int i; for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) { rcache = &iovad->rcaches[i]; cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu); spin_lock_irqsave(&cpu_rcache->lock, flags); iova_magazine_free_pfns(cpu_rcache->loaded, iovad); iova_magazine_free_pfns(cpu_rcache->prev, iovad); spin_unlock_irqrestore(&cpu_rcache->lock, flags); } } MODULE_AUTHOR("Anil S Keshavamurthy "); MODULE_LICENSE("GPL");