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![Robin Murphy](/assets/img/avatar_default.png)
For various reasons based on the allocator behaviour and typical use-cases at the time, when the max32_alloc_size optimisation was introduced it seemed reasonable to couple the reset of the tracked size to the update of cached32_node upon freeing a relevant IOVA. However, since subsequent optimisations focused on helping genuine 32-bit devices make best use of even more limited address spaces, it is now a lot more likely for cached32_node to be anywhere in a "full" 32-bit address space, and as such more likely for space to become available from IOVAs below that node being freed. At this point, the short-cut in __cached_rbnode_delete_update() really doesn't hold up any more, and we need to fix the logic to reliably provide the expected behaviour. We still want cached32_node to only move upwards, but we should reset the allocation size if *any* 32-bit space has become available. Reported-by: Yunfei Wang <yf.wang@mediatek.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Miles Chen <miles.chen@mediatek.com> Link: https://lore.kernel.org/r/033815732d83ca73b13c11485ac39336f15c3b40.1646318408.git.robin.murphy@arm.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
950 lines
24 KiB
C
950 lines
24 KiB
C
// 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 <anil.s.keshavamurthy@intel.com>
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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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/* The anchor node sits above the top of the usable address space */
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#define IOVA_ANCHOR ~0UL
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#define IOVA_RANGE_CACHE_MAX_SIZE 6 /* log of max cached IOVA range size (in pages) */
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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 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 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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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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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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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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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->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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}
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EXPORT_SYMBOL_GPL(init_iova_domain);
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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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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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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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if (free->pfn_lo < iovad->dma_32bit_pfn)
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iovad->max32_alloc_size = iovad->dma_32bit_pfn;
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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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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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return 0;
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}
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EXPORT_SYMBOL_GPL(iova_cache_get);
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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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* 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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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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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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return new_iova;
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}
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EXPORT_SYMBOL_GPL(alloc_iova);
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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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assert_spin_locked(&iovad->iova_rbtree_lock);
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while (node) {
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struct iova *iova = to_iova(node);
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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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return NULL;
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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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* 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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/* 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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* __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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* 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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{
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unsigned long iova_pfn;
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struct iova *new_iova;
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/*
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* Freeing non-power-of-two-sized allocations back into the IOVA caches
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* will come back to bite us badly, so we have to waste a bit of space
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* rounding up anything cacheable to make sure that can't happen. The
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* order of the unadjusted size will still match upon freeing.
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*/
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if (size < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1)))
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size = roundup_pow_of_two(size);
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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)
|
|
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.
|
|
*/
|
|
|
|
#define IOVA_MAG_SIZE 128
|
|
#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)
|
|
{
|
|
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;
|
|
}
|
|
|
|
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 || !iovad->rcaches)
|
|
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");
|