// SPDX-License-Identifier: GPL-2.0-only /* * Copyright © 2006-2009, Intel Corporation. * * Author: Anil S Keshavamurthy */ #include #include #include #include #include #include #include #include /* The anchor node sits above the top of the usable address space */ #define IOVA_ANCHOR ~0UL #define IOVA_RANGE_CACHE_MAX_SIZE 6 /* log of max cached IOVA range size (in pages) */ 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 free_iova_rcaches(struct iova_domain *iovad); static void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad); static void free_global_cached_iovas(struct iova_domain *iovad); static struct iova *to_iova(struct rb_node *node) { return rb_entry(node, struct iova, node); } 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->max32_alloc_size = iovad->dma_32bit_pfn; 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); } EXPORT_SYMBOL_GPL(init_iova_domain); 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 = to_iova(iovad->cached32_node); if (free == cached_iova || (free->pfn_hi < iovad->dma_32bit_pfn && free->pfn_lo >= cached_iova->pfn_lo)) iovad->cached32_node = rb_next(&free->node); if (free->pfn_lo < iovad->dma_32bit_pfn) iovad->max32_alloc_size = iovad->dma_32bit_pfn; cached_iova = to_iova(iovad->cached_node); if (free->pfn_lo >= cached_iova->pfn_lo) iovad->cached_node = rb_next(&free->node); } static struct rb_node *iova_find_limit(struct iova_domain *iovad, unsigned long limit_pfn) { struct rb_node *node, *next; /* * Ideally what we'd like to judge here is whether limit_pfn is close * enough to the highest-allocated IOVA that starting the allocation * walk from the anchor node will be quicker than this initial work to * find an exact starting point (especially if that ends up being the * anchor node anyway). This is an incredibly crude approximation which * only really helps the most likely case, but is at least trivially easy. */ if (limit_pfn > iovad->dma_32bit_pfn) return &iovad->anchor.node; node = iovad->rbroot.rb_node; while (to_iova(node)->pfn_hi < limit_pfn) node = node->rb_right; search_left: while (node->rb_left && to_iova(node->rb_left)->pfn_lo >= limit_pfn) node = node->rb_left; if (!node->rb_left) return node; next = node->rb_left; while (next->rb_right) { next = next->rb_right; if (to_iova(next)->pfn_lo >= limit_pfn) { node = next; goto search_left; } } return 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 = to_iova(*new); 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, retry_pfn; unsigned long align_mask = ~0UL; unsigned long high_pfn = limit_pfn, low_pfn = iovad->start_pfn; if (size_aligned) align_mask <<= fls_long(size - 1); /* Walk the tree backwards */ spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); if (limit_pfn <= iovad->dma_32bit_pfn && size >= iovad->max32_alloc_size) goto iova32_full; curr = __get_cached_rbnode(iovad, limit_pfn); curr_iova = to_iova(curr); retry_pfn = curr_iova->pfn_hi; retry: do { high_pfn = min(high_pfn, curr_iova->pfn_lo); new_pfn = (high_pfn - size) & align_mask; prev = curr; curr = rb_prev(curr); curr_iova = to_iova(curr); } while (curr && new_pfn <= curr_iova->pfn_hi && new_pfn >= low_pfn); if (high_pfn < size || new_pfn < low_pfn) { if (low_pfn == iovad->start_pfn && retry_pfn < limit_pfn) { high_pfn = limit_pfn; low_pfn = retry_pfn + 1; curr = iova_find_limit(iovad, limit_pfn); curr_iova = to_iova(curr); goto retry; } iovad->max32_alloc_size = size; goto iova32_full; } /* 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; iova32_full: spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); return -ENOMEM; } static struct kmem_cache *iova_cache; static unsigned int iova_cache_users; static DEFINE_MUTEX(iova_cache_mutex); static struct iova *alloc_iova_mem(void) { return kmem_cache_zalloc(iova_cache, GFP_ATOMIC | __GFP_NOWARN); } static void free_iova_mem(struct iova *iova) { if (iova->pfn_lo != IOVA_ANCHOR) kmem_cache_free(iova_cache, iova); } /** * 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 = to_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 remove_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); } /** * 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 domain 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); remove_iova(iovad, iova); spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); free_iova_mem(iova); } 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) { unsigned long flags; struct iova *iova; spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); iova = private_find_iova(iovad, pfn); if (!iova) { spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); return; } remove_iova(iovad, iova); spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); free_iova_mem(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 * @flush_rcache: - set to flush rcache on regular allocation failure * This function tries to satisfy an iova allocation from the rcache, * and falls back to regular allocation on failure. If regular allocation * fails too and the flush_rcache flag is set then the rcache will be flushed. */ unsigned long alloc_iova_fast(struct iova_domain *iovad, unsigned long size, unsigned long limit_pfn, bool flush_rcache) { unsigned long iova_pfn; struct iova *new_iova; /* * Freeing non-power-of-two-sized allocations back into the IOVA caches * will come back to bite us badly, so we have to waste a bit of space * rounding up anything cacheable to make sure that can't happen. The * order of the unadjusted size will still match upon freeing. */ if (size < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1))) size = roundup_pow_of_two(size); iova_pfn = iova_rcache_get(iovad, size, limit_pfn + 1); if (iova_pfn) return iova_pfn; retry: new_iova = alloc_iova(iovad, size, limit_pfn, true); if (!new_iova) { unsigned int cpu; if (!flush_rcache) return 0; /* Try replenishing IOVAs by flushing rcache. */ flush_rcache = false; for_each_online_cpu(cpu) free_cpu_cached_iovas(cpu, iovad); free_global_cached_iovas(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); static void iova_domain_free_rcaches(struct iova_domain *iovad) { cpuhp_state_remove_instance_nocalls(CPUHP_IOMMU_IOVA_DEAD, &iovad->cpuhp_dead); free_iova_rcaches(iovad); } /** * put_iova_domain - destroys the iova domain * @iovad: - iova domain in question. * All the iova's in that domain are destroyed. */ void put_iova_domain(struct iova_domain *iovad) { struct iova *iova, *tmp; if (iovad->rcaches) iova_domain_free_rcaches(iovad); rbtree_postorder_for_each_entry_safe(iova, tmp, &iovad->rbroot, node) free_iova_mem(iova); } 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 = to_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 address * 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 = to_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); /* * 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. */ /* * As kmalloc's buffer size is fixed to power of 2, 127 is chosen to * assure size of 'iova_magazine' to be 1024 bytes, so that no memory * will be wasted. Since only full magazines are inserted into the depot, * we don't need to waste PFN capacity on a separate list head either. */ #define IOVA_MAG_SIZE 127 #define IOVA_DEPOT_DELAY msecs_to_jiffies(100) struct iova_magazine { union { unsigned long size; struct iova_magazine *next; }; unsigned long pfns[IOVA_MAG_SIZE]; }; static_assert(!(sizeof(struct iova_magazine) & (sizeof(struct iova_magazine) - 1))); struct iova_cpu_rcache { spinlock_t lock; struct iova_magazine *loaded; struct iova_magazine *prev; }; struct iova_rcache { spinlock_t lock; unsigned int depot_size; struct iova_magazine *depot; struct iova_cpu_rcache __percpu *cpu_rcaches; struct iova_domain *iovad; struct delayed_work work; }; static struct kmem_cache *iova_magazine_cache; unsigned long iova_rcache_range(void) { return PAGE_SIZE << (IOVA_RANGE_CACHE_MAX_SIZE - 1); } static struct iova_magazine *iova_magazine_alloc(gfp_t flags) { struct iova_magazine *mag; mag = kmem_cache_alloc(iova_magazine_cache, flags); if (mag) mag->size = 0; return mag; } static void iova_magazine_free(struct iova_magazine *mag) { kmem_cache_free(iova_magazine_cache, mag); } static void iova_magazine_free_pfns(struct iova_magazine *mag, struct iova_domain *iovad) { unsigned long flags; int i; 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]); if (WARN_ON(!iova)) continue; remove_iova(iovad, iova); free_iova_mem(iova); } spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); mag->size = 0; } static bool iova_magazine_full(struct iova_magazine *mag) { return mag->size == IOVA_MAG_SIZE; } static bool iova_magazine_empty(struct iova_magazine *mag) { return mag->size == 0; } static unsigned long iova_magazine_pop(struct iova_magazine *mag, unsigned long limit_pfn) { int i; unsigned long pfn; /* Only fall back to the rbtree if we have no suitable pfns at all */ for (i = mag->size - 1; mag->pfns[i] > limit_pfn; i--) if (i == 0) return 0; /* Swap it to pop it */ pfn = mag->pfns[i]; mag->pfns[i] = mag->pfns[--mag->size]; return pfn; } static void iova_magazine_push(struct iova_magazine *mag, unsigned long pfn) { mag->pfns[mag->size++] = pfn; } static struct iova_magazine *iova_depot_pop(struct iova_rcache *rcache) { struct iova_magazine *mag = rcache->depot; /* * As the mag->next pointer is moved to rcache->depot and reset via * the mag->size assignment, mark it as a transient false positive. */ kmemleak_transient_leak(mag->next); rcache->depot = mag->next; mag->size = IOVA_MAG_SIZE; rcache->depot_size--; return mag; } static void iova_depot_push(struct iova_rcache *rcache, struct iova_magazine *mag) { mag->next = rcache->depot; rcache->depot = mag; rcache->depot_size++; } static void iova_depot_work_func(struct work_struct *work) { struct iova_rcache *rcache = container_of(work, typeof(*rcache), work.work); struct iova_magazine *mag = NULL; unsigned long flags; spin_lock_irqsave(&rcache->lock, flags); if (rcache->depot_size > num_online_cpus()) mag = iova_depot_pop(rcache); spin_unlock_irqrestore(&rcache->lock, flags); if (mag) { iova_magazine_free_pfns(mag, rcache->iovad); iova_magazine_free(mag); schedule_delayed_work(&rcache->work, IOVA_DEPOT_DELAY); } } int iova_domain_init_rcaches(struct iova_domain *iovad) { unsigned int cpu; int i, ret; iovad->rcaches = kcalloc(IOVA_RANGE_CACHE_MAX_SIZE, sizeof(struct iova_rcache), GFP_KERNEL); if (!iovad->rcaches) return -ENOMEM; for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) { struct iova_cpu_rcache *cpu_rcache; struct iova_rcache *rcache; rcache = &iovad->rcaches[i]; spin_lock_init(&rcache->lock); rcache->iovad = iovad; INIT_DELAYED_WORK(&rcache->work, iova_depot_work_func); rcache->cpu_rcaches = __alloc_percpu(sizeof(*cpu_rcache), cache_line_size()); if (!rcache->cpu_rcaches) { ret = -ENOMEM; goto out_err; } 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); if (!cpu_rcache->loaded || !cpu_rcache->prev) { ret = -ENOMEM; goto out_err; } } } ret = cpuhp_state_add_instance_nocalls(CPUHP_IOMMU_IOVA_DEAD, &iovad->cpuhp_dead); if (ret) goto out_err; return 0; out_err: free_iova_rcaches(iovad); return ret; } EXPORT_SYMBOL_GPL(iova_domain_init_rcaches); /* * 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_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); iova_depot_push(rcache, cpu_rcache->loaded); spin_unlock(&rcache->lock); schedule_delayed_work(&rcache->work, IOVA_DEPOT_DELAY); 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); 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) { iova_magazine_free(cpu_rcache->loaded); cpu_rcache->loaded = iova_depot_pop(rcache); 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 - size); } /* * free rcache data structures. */ static void free_iova_rcaches(struct iova_domain *iovad) { struct iova_rcache *rcache; struct iova_cpu_rcache *cpu_rcache; unsigned int cpu; for (int i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) { rcache = &iovad->rcaches[i]; if (!rcache->cpu_rcaches) break; for_each_possible_cpu(cpu) { cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu); iova_magazine_free(cpu_rcache->loaded); iova_magazine_free(cpu_rcache->prev); } free_percpu(rcache->cpu_rcaches); cancel_delayed_work_sync(&rcache->work); while (rcache->depot) iova_magazine_free(iova_depot_pop(rcache)); } kfree(iovad->rcaches); iovad->rcaches = NULL; } /* * free all the IOVA ranges cached by a cpu (used when cpu is unplugged) */ static 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); } } /* * free all the IOVA ranges of global cache */ static void free_global_cached_iovas(struct iova_domain *iovad) { struct iova_rcache *rcache; unsigned long flags; for (int i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) { rcache = &iovad->rcaches[i]; spin_lock_irqsave(&rcache->lock, flags); while (rcache->depot) { struct iova_magazine *mag = iova_depot_pop(rcache); iova_magazine_free_pfns(mag, iovad); iova_magazine_free(mag); } spin_unlock_irqrestore(&rcache->lock, flags); } } static int iova_cpuhp_dead(unsigned int cpu, struct hlist_node *node) { struct iova_domain *iovad; iovad = hlist_entry_safe(node, struct iova_domain, cpuhp_dead); free_cpu_cached_iovas(cpu, iovad); return 0; } int iova_cache_get(void) { int err = -ENOMEM; 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) goto out_err; iova_magazine_cache = kmem_cache_create("iommu_iova_magazine", sizeof(struct iova_magazine), 0, SLAB_HWCACHE_ALIGN, NULL); if (!iova_magazine_cache) goto out_err; err = cpuhp_setup_state_multi(CPUHP_IOMMU_IOVA_DEAD, "iommu/iova:dead", NULL, iova_cpuhp_dead); if (err) { pr_err("IOVA: Couldn't register cpuhp handler: %pe\n", ERR_PTR(err)); goto out_err; } } iova_cache_users++; mutex_unlock(&iova_cache_mutex); return 0; out_err: kmem_cache_destroy(iova_cache); kmem_cache_destroy(iova_magazine_cache); mutex_unlock(&iova_cache_mutex); return err; } 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) { cpuhp_remove_multi_state(CPUHP_IOMMU_IOVA_DEAD); kmem_cache_destroy(iova_cache); kmem_cache_destroy(iova_magazine_cache); } mutex_unlock(&iova_cache_mutex); } EXPORT_SYMBOL_GPL(iova_cache_put); MODULE_AUTHOR("Anil S Keshavamurthy "); MODULE_DESCRIPTION("IOMMU I/O Virtual Address management"); MODULE_LICENSE("GPL");