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1095 lines
27 KiB
1095 lines
27 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Copyright © 2006-2009, Intel Corporation. |
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* |
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* Author: Anil S Keshavamurthy <[email protected]> |
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*/ |
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|
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#include <linux/iova.h> |
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#include <linux/module.h> |
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#include <linux/slab.h> |
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#include <linux/smp.h> |
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#include <linux/bitops.h> |
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#include <linux/cpu.h> |
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|
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/* The anchor node sits above the top of the usable address space */ |
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#define IOVA_ANCHOR ~0UL |
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|
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static bool iova_rcache_insert(struct iova_domain *iovad, |
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unsigned long pfn, |
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unsigned long size); |
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static unsigned long iova_rcache_get(struct iova_domain *iovad, |
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unsigned long size, |
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unsigned long limit_pfn); |
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static void init_iova_rcaches(struct iova_domain *iovad); |
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static void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad); |
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static void free_iova_rcaches(struct iova_domain *iovad); |
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static void fq_destroy_all_entries(struct iova_domain *iovad); |
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static void fq_flush_timeout(struct timer_list *t); |
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|
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static int iova_cpuhp_dead(unsigned int cpu, struct hlist_node *node) |
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{ |
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struct iova_domain *iovad; |
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|
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iovad = hlist_entry_safe(node, struct iova_domain, cpuhp_dead); |
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free_cpu_cached_iovas(cpu, iovad); |
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return 0; |
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} |
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|
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static void free_global_cached_iovas(struct iova_domain *iovad); |
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static struct iova *to_iova(struct rb_node *node) |
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{ |
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return rb_entry(node, struct iova, node); |
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} |
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|
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void |
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init_iova_domain(struct iova_domain *iovad, unsigned long granule, |
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unsigned long start_pfn) |
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{ |
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/* |
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* IOVA granularity will normally be equal to the smallest |
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* supported IOMMU page size; both *must* be capable of |
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* representing individual CPU pages exactly. |
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*/ |
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BUG_ON((granule > PAGE_SIZE) || !is_power_of_2(granule)); |
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|
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spin_lock_init(&iovad->iova_rbtree_lock); |
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iovad->rbroot = RB_ROOT; |
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iovad->cached_node = &iovad->anchor.node; |
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iovad->cached32_node = &iovad->anchor.node; |
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iovad->granule = granule; |
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iovad->start_pfn = start_pfn; |
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iovad->dma_32bit_pfn = 1UL << (32 - iova_shift(iovad)); |
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iovad->max32_alloc_size = iovad->dma_32bit_pfn; |
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iovad->flush_cb = NULL; |
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iovad->fq = NULL; |
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iovad->anchor.pfn_lo = iovad->anchor.pfn_hi = IOVA_ANCHOR; |
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rb_link_node(&iovad->anchor.node, NULL, &iovad->rbroot.rb_node); |
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rb_insert_color(&iovad->anchor.node, &iovad->rbroot); |
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cpuhp_state_add_instance_nocalls(CPUHP_IOMMU_IOVA_DEAD, &iovad->cpuhp_dead); |
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init_iova_rcaches(iovad); |
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} |
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EXPORT_SYMBOL_GPL(init_iova_domain); |
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static bool has_iova_flush_queue(struct iova_domain *iovad) |
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{ |
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return !!iovad->fq; |
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} |
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|
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static void free_iova_flush_queue(struct iova_domain *iovad) |
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{ |
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if (!has_iova_flush_queue(iovad)) |
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return; |
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if (timer_pending(&iovad->fq_timer)) |
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del_timer(&iovad->fq_timer); |
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fq_destroy_all_entries(iovad); |
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free_percpu(iovad->fq); |
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iovad->fq = NULL; |
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iovad->flush_cb = NULL; |
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iovad->entry_dtor = NULL; |
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} |
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int init_iova_flush_queue(struct iova_domain *iovad, |
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iova_flush_cb flush_cb, iova_entry_dtor entry_dtor) |
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{ |
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struct iova_fq __percpu *queue; |
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int cpu; |
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atomic64_set(&iovad->fq_flush_start_cnt, 0); |
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atomic64_set(&iovad->fq_flush_finish_cnt, 0); |
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queue = alloc_percpu(struct iova_fq); |
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if (!queue) |
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return -ENOMEM; |
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iovad->flush_cb = flush_cb; |
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iovad->entry_dtor = entry_dtor; |
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for_each_possible_cpu(cpu) { |
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struct iova_fq *fq; |
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fq = per_cpu_ptr(queue, cpu); |
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fq->head = 0; |
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fq->tail = 0; |
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spin_lock_init(&fq->lock); |
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} |
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iovad->fq = queue; |
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timer_setup(&iovad->fq_timer, fq_flush_timeout, 0); |
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atomic_set(&iovad->fq_timer_on, 0); |
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return 0; |
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} |
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static struct rb_node * |
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__get_cached_rbnode(struct iova_domain *iovad, unsigned long limit_pfn) |
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{ |
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if (limit_pfn <= iovad->dma_32bit_pfn) |
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return iovad->cached32_node; |
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|
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return iovad->cached_node; |
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} |
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static void |
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__cached_rbnode_insert_update(struct iova_domain *iovad, struct iova *new) |
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{ |
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if (new->pfn_hi < iovad->dma_32bit_pfn) |
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iovad->cached32_node = &new->node; |
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else |
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iovad->cached_node = &new->node; |
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} |
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static void |
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__cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free) |
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{ |
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struct iova *cached_iova; |
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|
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cached_iova = to_iova(iovad->cached32_node); |
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if (free == cached_iova || |
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(free->pfn_hi < iovad->dma_32bit_pfn && |
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free->pfn_lo >= cached_iova->pfn_lo)) { |
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iovad->cached32_node = rb_next(&free->node); |
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iovad->max32_alloc_size = iovad->dma_32bit_pfn; |
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} |
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cached_iova = to_iova(iovad->cached_node); |
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if (free->pfn_lo >= cached_iova->pfn_lo) |
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iovad->cached_node = rb_next(&free->node); |
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} |
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static struct rb_node *iova_find_limit(struct iova_domain *iovad, unsigned long limit_pfn) |
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{ |
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struct rb_node *node, *next; |
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/* |
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* Ideally what we'd like to judge here is whether limit_pfn is close |
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* enough to the highest-allocated IOVA that starting the allocation |
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* walk from the anchor node will be quicker than this initial work to |
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* find an exact starting point (especially if that ends up being the |
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* anchor node anyway). This is an incredibly crude approximation which |
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* only really helps the most likely case, but is at least trivially easy. |
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*/ |
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if (limit_pfn > iovad->dma_32bit_pfn) |
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return &iovad->anchor.node; |
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node = iovad->rbroot.rb_node; |
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while (to_iova(node)->pfn_hi < limit_pfn) |
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node = node->rb_right; |
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search_left: |
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while (node->rb_left && to_iova(node->rb_left)->pfn_lo >= limit_pfn) |
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node = node->rb_left; |
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if (!node->rb_left) |
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return node; |
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next = node->rb_left; |
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while (next->rb_right) { |
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next = next->rb_right; |
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if (to_iova(next)->pfn_lo >= limit_pfn) { |
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node = next; |
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goto search_left; |
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} |
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} |
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return node; |
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} |
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/* Insert the iova into domain rbtree by holding writer lock */ |
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static void |
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iova_insert_rbtree(struct rb_root *root, struct iova *iova, |
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struct rb_node *start) |
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{ |
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struct rb_node **new, *parent = NULL; |
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new = (start) ? &start : &(root->rb_node); |
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/* Figure out where to put new node */ |
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while (*new) { |
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struct iova *this = to_iova(*new); |
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parent = *new; |
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if (iova->pfn_lo < this->pfn_lo) |
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new = &((*new)->rb_left); |
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else if (iova->pfn_lo > this->pfn_lo) |
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new = &((*new)->rb_right); |
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else { |
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WARN_ON(1); /* this should not happen */ |
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return; |
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} |
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} |
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/* Add new node and rebalance tree. */ |
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rb_link_node(&iova->node, parent, new); |
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rb_insert_color(&iova->node, root); |
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} |
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static int __alloc_and_insert_iova_range(struct iova_domain *iovad, |
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unsigned long size, unsigned long limit_pfn, |
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struct iova *new, bool size_aligned) |
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{ |
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struct rb_node *curr, *prev; |
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struct iova *curr_iova; |
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unsigned long flags; |
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unsigned long new_pfn, retry_pfn; |
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unsigned long align_mask = ~0UL; |
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unsigned long high_pfn = limit_pfn, low_pfn = iovad->start_pfn; |
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if (size_aligned) |
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align_mask <<= fls_long(size - 1); |
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/* Walk the tree backwards */ |
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spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); |
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if (limit_pfn <= iovad->dma_32bit_pfn && |
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size >= iovad->max32_alloc_size) |
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goto iova32_full; |
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curr = __get_cached_rbnode(iovad, limit_pfn); |
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curr_iova = to_iova(curr); |
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retry_pfn = curr_iova->pfn_hi + 1; |
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retry: |
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do { |
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high_pfn = min(high_pfn, curr_iova->pfn_lo); |
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new_pfn = (high_pfn - size) & align_mask; |
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prev = curr; |
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curr = rb_prev(curr); |
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curr_iova = to_iova(curr); |
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} while (curr && new_pfn <= curr_iova->pfn_hi && new_pfn >= low_pfn); |
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if (high_pfn < size || new_pfn < low_pfn) { |
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if (low_pfn == iovad->start_pfn && retry_pfn < limit_pfn) { |
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high_pfn = limit_pfn; |
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low_pfn = retry_pfn; |
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curr = iova_find_limit(iovad, limit_pfn); |
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curr_iova = to_iova(curr); |
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goto retry; |
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} |
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iovad->max32_alloc_size = size; |
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goto iova32_full; |
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} |
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/* pfn_lo will point to size aligned address if size_aligned is set */ |
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new->pfn_lo = new_pfn; |
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new->pfn_hi = new->pfn_lo + size - 1; |
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/* If we have 'prev', it's a valid place to start the insertion. */ |
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iova_insert_rbtree(&iovad->rbroot, new, prev); |
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__cached_rbnode_insert_update(iovad, new); |
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spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); |
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return 0; |
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iova32_full: |
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spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); |
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return -ENOMEM; |
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} |
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static struct kmem_cache *iova_cache; |
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static unsigned int iova_cache_users; |
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static DEFINE_MUTEX(iova_cache_mutex); |
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static struct iova *alloc_iova_mem(void) |
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{ |
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return kmem_cache_zalloc(iova_cache, GFP_ATOMIC | __GFP_NOWARN); |
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} |
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static void free_iova_mem(struct iova *iova) |
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{ |
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if (iova->pfn_lo != IOVA_ANCHOR) |
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kmem_cache_free(iova_cache, iova); |
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} |
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int iova_cache_get(void) |
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{ |
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mutex_lock(&iova_cache_mutex); |
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if (!iova_cache_users) { |
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int ret; |
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|
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ret = cpuhp_setup_state_multi(CPUHP_IOMMU_IOVA_DEAD, "iommu/iova:dead", NULL, |
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iova_cpuhp_dead); |
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if (ret) { |
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mutex_unlock(&iova_cache_mutex); |
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pr_err("Couldn't register cpuhp handler\n"); |
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return ret; |
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} |
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iova_cache = kmem_cache_create( |
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"iommu_iova", sizeof(struct iova), 0, |
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SLAB_HWCACHE_ALIGN, NULL); |
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if (!iova_cache) { |
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cpuhp_remove_multi_state(CPUHP_IOMMU_IOVA_DEAD); |
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mutex_unlock(&iova_cache_mutex); |
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pr_err("Couldn't create iova cache\n"); |
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return -ENOMEM; |
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} |
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} |
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iova_cache_users++; |
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mutex_unlock(&iova_cache_mutex); |
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|
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(iova_cache_get); |
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|
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void iova_cache_put(void) |
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{ |
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mutex_lock(&iova_cache_mutex); |
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if (WARN_ON(!iova_cache_users)) { |
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mutex_unlock(&iova_cache_mutex); |
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return; |
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} |
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iova_cache_users--; |
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if (!iova_cache_users) { |
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cpuhp_remove_multi_state(CPUHP_IOMMU_IOVA_DEAD); |
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kmem_cache_destroy(iova_cache); |
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} |
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mutex_unlock(&iova_cache_mutex); |
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} |
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EXPORT_SYMBOL_GPL(iova_cache_put); |
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|
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/** |
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* alloc_iova - allocates an iova |
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* @iovad: - iova domain in question |
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* @size: - size of page frames to allocate |
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* @limit_pfn: - max limit address |
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* @size_aligned: - set if size_aligned address range is required |
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* This function allocates an iova in the range iovad->start_pfn to limit_pfn, |
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* searching top-down from limit_pfn to iovad->start_pfn. If the size_aligned |
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* flag is set then the allocated address iova->pfn_lo will be naturally |
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* aligned on roundup_power_of_two(size). |
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*/ |
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struct iova * |
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alloc_iova(struct iova_domain *iovad, unsigned long size, |
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unsigned long limit_pfn, |
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bool size_aligned) |
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{ |
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struct iova *new_iova; |
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int ret; |
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|
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new_iova = alloc_iova_mem(); |
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if (!new_iova) |
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return NULL; |
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ret = __alloc_and_insert_iova_range(iovad, size, limit_pfn + 1, |
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new_iova, size_aligned); |
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|
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if (ret) { |
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free_iova_mem(new_iova); |
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return NULL; |
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} |
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|
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return new_iova; |
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} |
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EXPORT_SYMBOL_GPL(alloc_iova); |
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|
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static struct iova * |
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private_find_iova(struct iova_domain *iovad, unsigned long pfn) |
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{ |
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struct rb_node *node = iovad->rbroot.rb_node; |
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|
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assert_spin_locked(&iovad->iova_rbtree_lock); |
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|
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while (node) { |
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struct iova *iova = to_iova(node); |
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|
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if (pfn < iova->pfn_lo) |
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node = node->rb_left; |
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else if (pfn > iova->pfn_hi) |
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node = node->rb_right; |
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else |
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return iova; /* pfn falls within iova's range */ |
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} |
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|
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return NULL; |
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} |
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|
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static void remove_iova(struct iova_domain *iovad, struct iova *iova) |
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{ |
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assert_spin_locked(&iovad->iova_rbtree_lock); |
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__cached_rbnode_delete_update(iovad, iova); |
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rb_erase(&iova->node, &iovad->rbroot); |
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} |
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|
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/** |
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* find_iova - finds an iova for a given pfn |
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* @iovad: - iova domain in question. |
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* @pfn: - page frame number |
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* This function finds and returns an iova belonging to the |
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* given domain which matches the given pfn. |
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*/ |
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struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn) |
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{ |
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unsigned long flags; |
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struct iova *iova; |
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|
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/* Take the lock so that no other thread is manipulating the rbtree */ |
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spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); |
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iova = private_find_iova(iovad, pfn); |
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spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); |
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return iova; |
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} |
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EXPORT_SYMBOL_GPL(find_iova); |
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|
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/** |
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* __free_iova - frees the given iova |
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* @iovad: iova domain in question. |
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* @iova: iova in question. |
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* Frees the given iova belonging to the giving domain |
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*/ |
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void |
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__free_iova(struct iova_domain *iovad, struct iova *iova) |
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{ |
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unsigned long flags; |
|
|
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spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); |
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remove_iova(iovad, iova); |
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spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); |
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free_iova_mem(iova); |
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} |
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EXPORT_SYMBOL_GPL(__free_iova); |
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|
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/** |
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* free_iova - finds and frees the iova for a given pfn |
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* @iovad: - iova domain in question. |
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* @pfn: - pfn that is allocated previously |
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* This functions finds an iova for a given pfn and then |
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* frees the iova from that domain. |
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*/ |
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void |
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free_iova(struct iova_domain *iovad, unsigned long pfn) |
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{ |
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unsigned long flags; |
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struct iova *iova; |
|
|
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spin_lock_irqsave(&iovad->iova_rbtree_lock, flags); |
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iova = private_find_iova(iovad, pfn); |
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if (!iova) { |
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spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); |
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return; |
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} |
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remove_iova(iovad, iova); |
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spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags); |
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free_iova_mem(iova); |
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} |
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EXPORT_SYMBOL_GPL(free_iova); |
|
|
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/** |
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* alloc_iova_fast - allocates an iova from rcache |
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* @iovad: - iova domain in question |
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* @size: - size of page frames to allocate |
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* @limit_pfn: - max limit address |
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* @flush_rcache: - set to flush rcache on regular allocation failure |
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* This function tries to satisfy an iova allocation from the rcache, |
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* and falls back to regular allocation on failure. If regular allocation |
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* fails too and the flush_rcache flag is set then the rcache will be flushed. |
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*/ |
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unsigned long |
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alloc_iova_fast(struct iova_domain *iovad, unsigned long size, |
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unsigned long limit_pfn, bool flush_rcache) |
|
{ |
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unsigned long iova_pfn; |
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struct iova *new_iova; |
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|
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iova_pfn = iova_rcache_get(iovad, size, limit_pfn + 1); |
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if (iova_pfn) |
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return iova_pfn; |
|
|
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retry: |
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new_iova = alloc_iova(iovad, size, limit_pfn, true); |
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if (!new_iova) { |
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unsigned int cpu; |
|
|
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if (!flush_rcache) |
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return 0; |
|
|
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/* Try replenishing IOVAs by flushing rcache. */ |
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flush_rcache = false; |
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for_each_online_cpu(cpu) |
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free_cpu_cached_iovas(cpu, iovad); |
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free_global_cached_iovas(iovad); |
|
goto retry; |
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} |
|
|
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return new_iova->pfn_lo; |
|
} |
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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 |
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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; |
|
unsigned long flags; |
|
unsigned idx; |
|
|
|
/* |
|
* Order against the IOMMU driver's pagetable update from unmapping |
|
* @pte, to guarantee that iova_domain_flush() observes that if called |
|
* from a different CPU before we release the lock below. Full barrier |
|
* so it also pairs with iommu_dma_init_fq() to avoid seeing partially |
|
* written fq state here. |
|
*/ |
|
smp_mb(); |
|
|
|
fq = raw_cpu_ptr(iovad->fq); |
|
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_xchg(&iovad->fq_timer_on, 1)) |
|
mod_timer(&iovad->fq_timer, |
|
jiffies + msecs_to_jiffies(IOVA_FQ_TIMEOUT)); |
|
} |
|
|
|
/** |
|
* 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; |
|
|
|
cpuhp_state_remove_instance_nocalls(CPUHP_IOMMU_IOVA_DEAD, |
|
&iovad->cpuhp_dead); |
|
|
|
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 = 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. |
|
*/ |
|
|
|
#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]); |
|
|
|
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 && 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) |
|
*/ |
|
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 <[email protected]>"); |
|
MODULE_LICENSE("GPL");
|
|
|