diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/iommu/iova.c | 959 |
1 files changed, 959 insertions, 0 deletions
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c new file mode 100644 index 0000000000..10b9646009 --- /dev/null +++ b/drivers/iommu/iova.c @@ -0,0 +1,959 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright © 2006-2009, Intel Corporation. + * + * Author: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> + */ + +#include <linux/iova.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/smp.h> +#include <linux/bitops.h> +#include <linux/cpu.h> + +/* 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_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad); +static void free_iova_rcaches(struct iova_domain *iovad); + +unsigned long iova_rcache_range(void) +{ + return PAGE_SIZE << (IOVA_RANGE_CACHE_MAX_SIZE - 1); +} + +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; +} + +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); +} + +int iova_cache_get(void) +{ + mutex_lock(&iova_cache_mutex); + if (!iova_cache_users) { + int ret; + + ret = cpuhp_setup_state_multi(CPUHP_IOMMU_IOVA_DEAD, "iommu/iova:dead", NULL, + iova_cpuhp_dead); + if (ret) { + mutex_unlock(&iova_cache_mutex); + pr_err("Couldn't register cpuhp handler\n"); + return ret; + } + + iova_cache = kmem_cache_create( + "iommu_iova", sizeof(struct iova), 0, + SLAB_HWCACHE_ALIGN, NULL); + if (!iova_cache) { + cpuhp_remove_multi_state(CPUHP_IOMMU_IOVA_DEAD); + mutex_unlock(&iova_cache_mutex); + pr_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) { + cpuhp_remove_multi_state(CPUHP_IOMMU_IOVA_DEAD); + 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 = 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 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 = 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. + */ +#define IOVA_MAG_SIZE 127 +#define MAX_GLOBAL_MAGS 32 /* magazines per bin */ + +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; +}; + +struct iova_rcache { + spinlock_t lock; + unsigned long depot_size; + struct iova_magazine *depot[MAX_GLOBAL_MAGS]; + struct iova_cpu_rcache __percpu *cpu_rcaches; +}; + +static struct iova_magazine *iova_magazine_alloc(gfp_t flags) +{ + struct iova_magazine *mag; + + mag = kmalloc(sizeof(*mag), flags); + if (mag) + mag->size = 0; + + return mag; +} + +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; + + 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; +} + +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->depot_size = 0; + 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_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 - 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; + int i, j; + + for (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); + for (j = 0; j < rcache->depot_size; ++j) + iova_magazine_free(rcache->depot[j]); + } + + 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; + int i, j; + + for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) { + rcache = &iovad->rcaches[i]; + spin_lock_irqsave(&rcache->lock, flags); + for (j = 0; j < rcache->depot_size; ++j) { + iova_magazine_free_pfns(rcache->depot[j], iovad); + iova_magazine_free(rcache->depot[j]); + } + rcache->depot_size = 0; + spin_unlock_irqrestore(&rcache->lock, flags); + } +} +MODULE_AUTHOR("Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>"); +MODULE_LICENSE("GPL"); |