| // 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 |
| |
| 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(struct timer_list *t); |
| |
| 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->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); |
| |
| bool has_iova_flush_queue(struct iova_domain *iovad) |
| { |
| return !!iovad->fq; |
| } |
| |
| static void free_iova_flush_queue(struct iova_domain *iovad) |
| { |
| if (!has_iova_flush_queue(iovad)) |
| 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) |
| { |
| struct iova_fq __percpu *queue; |
| int cpu; |
| |
| atomic64_set(&iovad->fq_flush_start_cnt, 0); |
| atomic64_set(&iovad->fq_flush_finish_cnt, 0); |
| |
| queue = alloc_percpu(struct iova_fq); |
| if (!queue) |
| 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(queue, cpu); |
| fq->head = 0; |
| fq->tail = 0; |
| |
| spin_lock_init(&fq->lock); |
| } |
| |
| smp_wmb(); |
| |
| iovad->fq = queue; |
| |
| timer_setup(&iovad->fq_timer, fq_flush_timeout, 0); |
| 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 == cached_iova || |
| (free->pfn_hi < iovad->dma_32bit_pfn && |
| free->pfn_lo >= cached_iova->pfn_lo)) { |
| iovad->cached32_node = rb_next(&free->node); |
| iovad->max32_alloc_size = iovad->dma_32bit_pfn; |
| } |
| |
| 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); |
| if (limit_pfn <= iovad->dma_32bit_pfn && |
| size >= iovad->max32_alloc_size) |
| goto iova32_full; |
| |
| 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) { |
| 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); |
| |
| struct iova *alloc_iova_mem(void) |
| { |
| return kmem_cache_zalloc(iova_cache, GFP_ATOMIC | __GFP_NOWARN); |
| } |
| 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); |
| 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) |
| 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 |
| * @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; |
| |
| 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); |
| 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(struct timer_list *t) |
| { |
| struct iova_domain *iovad = from_timer(iovad, t, fq_timer); |
| 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 = raw_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); |
| |
| /* Avoid false sharing as much as possible. */ |
| if (!atomic_read(&iovad->fq_timer_on) && |
| !atomic_cmpxchg(&iovad->fq_timer_on, 0, 1)) |
| mod_timer(&iovad->fq_timer, |
| jiffies + msecs_to_jiffies(IOVA_FQ_TIMEOUT)); |
| } |
| 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 iova *iova, *tmp; |
| |
| free_iova_flush_queue(iovad); |
| free_iova_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 = 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; |
| |
| if (iova->pfn_lo == IOVA_ANCHOR) |
| continue; |
| |
| new_iova = reserve_iova(to, iova->pfn_lo, iova->pfn_hi); |
| if (!new_iova) |
| pr_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) |
| { |
| int i; |
| unsigned long pfn; |
| |
| BUG_ON(iova_magazine_empty(mag)); |
| |
| /* 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) |
| { |
| 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 - 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]; |
| 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]); |
| } |
| } |
| |
| /* |
| * 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 <anil.s.keshavamurthy@intel.com>"); |
| MODULE_LICENSE("GPL"); |