Re: [PATCH v2] iova: Re-order code to remove forward declarations
From: John Garry
Date: Mon Aug 15 2022 - 07:05:57 EST
On 26/07/2022 16:26, John Garry wrote:
Hi Robin,
Any opinion on this patch?
Thanks,
John
Now that the FQ code has been moved to dma-iommu.c and also the rcache-
related structures have been brought into iova.c, let's re-order the code
to remove all the forward declarations.
The general order will be as follows:
- RB tree code
- iova management
- magazine helpers
- rcache code and "fast" APIs
- iova domain public APIs
Re-order prototypes in iova.h to follow the same general group ordering.
A couple of pre-existing checkpatch warnings are also remedied:
A suspect indentation is also corrected:
WARNING: suspect code indent for conditional statements (16, 32)
#374: FILE: drivers/iommu/iova.c:194:
+ } else if (overlap)
+ break;
WARNING: Block comments should align the * on each line
#1038: FILE: drivers/iommu/iova.c:787:
+ * fails too and the flush_rcache flag is set then the rcache will be flushed.
+*/
No functional change intended.
Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
---
Differences to v1:
- tweak ordering a bit
- rebase
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index e44f565c5319..ddac9dcf97c6 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -17,75 +17,45 @@
#define IOVA_RANGE_CACHE_MAX_SIZE 6 /* log of max cached IOVA range size (in pages) */
-static bool iova_rcache_insert(struct iova_domain *iovad,
- unsigned long pfn,
- unsigned long size);
-static unsigned long iova_rcache_get(struct iova_domain *iovad,
- unsigned long size,
- unsigned long limit_pfn);
-static void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad);
-static void free_iova_rcaches(struct iova_domain *iovad);
+/*
+ * 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.
+ */
-static int iova_cpuhp_dead(unsigned int cpu, struct hlist_node *node)
-{
- struct iova_domain *iovad;
+/*
+ * As kmalloc's buffer size is fixed to power of 2, 127 is chosen to
+ * assure size of 'iova_magazine' to be 1024 bytes, so that no memory
+ * will be wasted.
+ */
+#define IOVA_MAG_SIZE 127
+#define MAX_GLOBAL_MAGS 32 /* magazines per bin */
- iovad = hlist_entry_safe(node, struct iova_domain, cpuhp_dead);
+struct iova_magazine {
+ unsigned long size;
+ unsigned long pfns[IOVA_MAG_SIZE];
+};
- free_cpu_cached_iovas(cpu, iovad);
- return 0;
-}
+struct iova_cpu_rcache {
+ spinlock_t lock;
+ struct iova_magazine *loaded;
+ struct iova_magazine *prev;
+};
-static void free_global_cached_iovas(struct iova_domain *iovad);
+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 *to_iova(struct rb_node *node)
{
return rb_entry(node, struct iova, node);
}
-void
-init_iova_domain(struct iova_domain *iovad, unsigned long granule,
- unsigned long start_pfn)
-{
- /*
- * IOVA granularity will normally be equal to the smallest
- * supported IOMMU page size; both *must* be capable of
- * representing individual CPU pages exactly.
- */
- BUG_ON((granule > PAGE_SIZE) || !is_power_of_2(granule));
-
- spin_lock_init(&iovad->iova_rbtree_lock);
- iovad->rbroot = RB_ROOT;
- iovad->cached_node = &iovad->anchor.node;
- iovad->cached32_node = &iovad->anchor.node;
- iovad->granule = granule;
- iovad->start_pfn = start_pfn;
- iovad->dma_32bit_pfn = 1UL << (32 - iova_shift(iovad));
- iovad->max32_alloc_size = iovad->dma_32bit_pfn;
- iovad->anchor.pfn_lo = iovad->anchor.pfn_hi = IOVA_ANCHOR;
- rb_link_node(&iovad->anchor.node, NULL, &iovad->rbroot.rb_node);
- rb_insert_color(&iovad->anchor.node, &iovad->rbroot);
-}
-EXPORT_SYMBOL_GPL(init_iova_domain);
-
-static struct rb_node *
-__get_cached_rbnode(struct iova_domain *iovad, unsigned long limit_pfn)
-{
- if (limit_pfn <= iovad->dma_32bit_pfn)
- return iovad->cached32_node;
-
- return iovad->cached_node;
-}
-
-static void
-__cached_rbnode_insert_update(struct iova_domain *iovad, struct iova *new)
-{
- if (new->pfn_hi < iovad->dma_32bit_pfn)
- iovad->cached32_node = &new->node;
- else
- iovad->cached_node = &new->node;
-}
-
static void
__cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free)
{
@@ -105,43 +75,6 @@ __cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free)
iovad->cached_node = rb_next(&free->node);
}
-static struct rb_node *iova_find_limit(struct iova_domain *iovad, unsigned long limit_pfn)
-{
- struct rb_node *node, *next;
- /*
- * Ideally what we'd like to judge here is whether limit_pfn is close
- * enough to the highest-allocated IOVA that starting the allocation
- * walk from the anchor node will be quicker than this initial work to
- * find an exact starting point (especially if that ends up being the
- * anchor node anyway). This is an incredibly crude approximation which
- * only really helps the most likely case, but is at least trivially easy.
- */
- if (limit_pfn > iovad->dma_32bit_pfn)
- return &iovad->anchor.node;
-
- node = iovad->rbroot.rb_node;
- while (to_iova(node)->pfn_hi < limit_pfn)
- node = node->rb_right;
-
-search_left:
- while (node->rb_left && to_iova(node->rb_left)->pfn_lo >= limit_pfn)
- node = node->rb_left;
-
- if (!node->rb_left)
- return node;
-
- next = node->rb_left;
- while (next->rb_right) {
- next = next->rb_right;
- if (to_iova(next)->pfn_lo >= limit_pfn) {
- node = next;
- goto search_left;
- }
- }
-
- return node;
-}
-
/* Insert the iova into domain rbtree by holding writer lock */
static void
iova_insert_rbtree(struct rb_root *root, struct iova *iova,
@@ -170,65 +103,15 @@ iova_insert_rbtree(struct rb_root *root, struct iova *iova,
rb_insert_color(&iova->node, root);
}
-static int __alloc_and_insert_iova_range(struct iova_domain *iovad,
- unsigned long size, unsigned long limit_pfn,
- struct iova *new, bool size_aligned)
+static int
+__is_range_overlap(struct rb_node *node,
+ unsigned long pfn_lo, unsigned long pfn_hi)
{
- struct rb_node *curr, *prev;
- struct iova *curr_iova;
- unsigned long flags;
- unsigned long new_pfn, retry_pfn;
- unsigned long align_mask = ~0UL;
- unsigned long high_pfn = limit_pfn, low_pfn = iovad->start_pfn;
-
- if (size_aligned)
- align_mask <<= fls_long(size - 1);
-
- /* Walk the tree backwards */
- spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
- if (limit_pfn <= iovad->dma_32bit_pfn &&
- size >= iovad->max32_alloc_size)
- goto iova32_full;
-
- curr = __get_cached_rbnode(iovad, limit_pfn);
- curr_iova = to_iova(curr);
- retry_pfn = curr_iova->pfn_hi + 1;
-
-retry:
- do {
- high_pfn = min(high_pfn, curr_iova->pfn_lo);
- new_pfn = (high_pfn - size) & align_mask;
- prev = curr;
- curr = rb_prev(curr);
- curr_iova = to_iova(curr);
- } while (curr && new_pfn <= curr_iova->pfn_hi && new_pfn >= low_pfn);
-
- if (high_pfn < size || new_pfn < low_pfn) {
- if (low_pfn == iovad->start_pfn && retry_pfn < limit_pfn) {
- high_pfn = limit_pfn;
- low_pfn = retry_pfn;
- curr = iova_find_limit(iovad, limit_pfn);
- curr_iova = to_iova(curr);
- goto retry;
- }
- iovad->max32_alloc_size = size;
- goto iova32_full;
- }
-
- /* pfn_lo will point to size aligned address if size_aligned is set */
- new->pfn_lo = new_pfn;
- new->pfn_hi = new->pfn_lo + size - 1;
-
- /* If we have 'prev', it's a valid place to start the insertion. */
- iova_insert_rbtree(&iovad->rbroot, new, prev);
- __cached_rbnode_insert_update(iovad, new);
+ struct iova *iova = to_iova(node);
- spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+ if ((pfn_lo <= iova->pfn_hi) && (pfn_hi >= iova->pfn_lo))
+ return 1;
return 0;
-
-iova32_full:
- spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
- return -ENOMEM;
}
static struct kmem_cache *iova_cache;
@@ -246,88 +129,87 @@ static void free_iova_mem(struct iova *iova)
kmem_cache_free(iova_cache, iova);
}
-int iova_cache_get(void)
+static inline struct iova *
+alloc_and_init_iova(unsigned long pfn_lo, unsigned long pfn_hi)
{
- mutex_lock(&iova_cache_mutex);
- if (!iova_cache_users) {
- int ret;
-
- ret = cpuhp_setup_state_multi(CPUHP_IOMMU_IOVA_DEAD, "iommu/iova:dead", NULL,
- iova_cpuhp_dead);
- if (ret) {
- mutex_unlock(&iova_cache_mutex);
- pr_err("Couldn't register cpuhp handler\n");
- return ret;
- }
+ struct iova *iova;
- iova_cache = kmem_cache_create(
- "iommu_iova", sizeof(struct iova), 0,
- SLAB_HWCACHE_ALIGN, NULL);
- if (!iova_cache) {
- cpuhp_remove_multi_state(CPUHP_IOMMU_IOVA_DEAD);
- mutex_unlock(&iova_cache_mutex);
- pr_err("Couldn't create iova cache\n");
- return -ENOMEM;
- }
+ iova = alloc_iova_mem();
+ if (iova) {
+ iova->pfn_lo = pfn_lo;
+ iova->pfn_hi = pfn_hi;
}
- iova_cache_users++;
- mutex_unlock(&iova_cache_mutex);
+ return iova;
+}
- return 0;
+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;
}
-EXPORT_SYMBOL_GPL(iova_cache_get);
-void iova_cache_put(void)
+static void
+__adjust_overlap_range(struct iova *iova,
+ unsigned long *pfn_lo, unsigned long *pfn_hi)
{
- mutex_lock(&iova_cache_mutex);
- if (WARN_ON(!iova_cache_users)) {
- mutex_unlock(&iova_cache_mutex);
- return;
- }
- iova_cache_users--;
- if (!iova_cache_users) {
- cpuhp_remove_multi_state(CPUHP_IOMMU_IOVA_DEAD);
- kmem_cache_destroy(iova_cache);
- }
- mutex_unlock(&iova_cache_mutex);
+ if (*pfn_lo < iova->pfn_lo)
+ iova->pfn_lo = *pfn_lo;
+ if (*pfn_hi > iova->pfn_hi)
+ *pfn_lo = iova->pfn_hi + 1;
}
-EXPORT_SYMBOL_GPL(iova_cache_put);
/**
- * alloc_iova - allocates an iova
- * @iovad: - iova domain in question
- * @size: - size of page frames to allocate
- * @limit_pfn: - max limit address
- * @size_aligned: - set if size_aligned address range is required
- * This function allocates an iova in the range iovad->start_pfn to limit_pfn,
- * searching top-down from limit_pfn to iovad->start_pfn. If the size_aligned
- * flag is set then the allocated address iova->pfn_lo will be naturally
- * aligned on roundup_power_of_two(size).
- */
-struct iova *
-alloc_iova(struct iova_domain *iovad, unsigned long size,
- unsigned long limit_pfn,
- bool size_aligned)
+ * 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 iova *new_iova;
- int ret;
+ struct rb_node *node;
+ unsigned long flags;
+ struct iova *iova;
+ unsigned int overlap = 0;
- new_iova = alloc_iova_mem();
- if (!new_iova)
+ /* Don't allow nonsensical pfns */
+ if (WARN_ON((pfn_hi | pfn_lo) > (ULLONG_MAX >> iova_shift(iovad))))
return NULL;
- ret = __alloc_and_insert_iova_range(iovad, size, limit_pfn + 1,
- new_iova, size_aligned);
-
- if (ret) {
- free_iova_mem(new_iova);
- return NULL;
+ 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;
}
- return new_iova;
+ /* 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(alloc_iova);
+EXPORT_SYMBOL_GPL(reserve_iova);
static struct iova *
private_find_iova(struct iova_domain *iovad, unsigned long pfn)
@@ -357,6 +239,122 @@ static void remove_iova(struct iova_domain *iovad, struct iova *iova)
rb_erase(&iova->node, &iovad->rbroot);
}
+static struct rb_node *
+__get_cached_rbnode(struct iova_domain *iovad, unsigned long limit_pfn)
+{
+ if (limit_pfn <= iovad->dma_32bit_pfn)
+ return iovad->cached32_node;
+
+ return iovad->cached_node;
+}
+
+static void
+__cached_rbnode_insert_update(struct iova_domain *iovad, struct iova *new)
+{
+ if (new->pfn_hi < iovad->dma_32bit_pfn)
+ iovad->cached32_node = &new->node;
+ else
+ iovad->cached_node = &new->node;
+}
+
+static struct rb_node *iova_find_limit(struct iova_domain *iovad, unsigned long limit_pfn)
+{
+ struct rb_node *node, *next;
+ /*
+ * Ideally what we'd like to judge here is whether limit_pfn is close
+ * enough to the highest-allocated IOVA that starting the allocation
+ * walk from the anchor node will be quicker than this initial work to
+ * find an exact starting point (especially if that ends up being the
+ * anchor node anyway). This is an incredibly crude approximation which
+ * only really helps the most likely case, but is at least trivially easy.
+ */
+ if (limit_pfn > iovad->dma_32bit_pfn)
+ return &iovad->anchor.node;
+
+ node = iovad->rbroot.rb_node;
+ while (to_iova(node)->pfn_hi < limit_pfn)
+ node = node->rb_right;
+
+search_left:
+ while (node->rb_left && to_iova(node->rb_left)->pfn_lo >= limit_pfn)
+ node = node->rb_left;
+
+ if (!node->rb_left)
+ return node;
+
+ next = node->rb_left;
+ while (next->rb_right) {
+ next = next->rb_right;
+ if (to_iova(next)->pfn_lo >= limit_pfn) {
+ node = next;
+ goto search_left;
+ }
+ }
+
+ return node;
+}
+
+static int __alloc_and_insert_iova_range(struct iova_domain *iovad,
+ unsigned long size, unsigned long limit_pfn,
+ struct iova *new, bool size_aligned)
+{
+ struct rb_node *curr, *prev;
+ struct iova *curr_iova;
+ unsigned long flags;
+ unsigned long new_pfn, retry_pfn;
+ unsigned long align_mask = ~0UL;
+ unsigned long high_pfn = limit_pfn, low_pfn = iovad->start_pfn;
+
+ if (size_aligned)
+ align_mask <<= fls_long(size - 1);
+
+ /* Walk the tree backwards */
+ spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
+ if (limit_pfn <= iovad->dma_32bit_pfn &&
+ size >= iovad->max32_alloc_size)
+ goto iova32_full;
+
+ curr = __get_cached_rbnode(iovad, limit_pfn);
+ curr_iova = to_iova(curr);
+ retry_pfn = curr_iova->pfn_hi + 1;
+
+retry:
+ do {
+ high_pfn = min(high_pfn, curr_iova->pfn_lo);
+ new_pfn = (high_pfn - size) & align_mask;
+ prev = curr;
+ curr = rb_prev(curr);
+ curr_iova = to_iova(curr);
+ } while (curr && new_pfn <= curr_iova->pfn_hi && new_pfn >= low_pfn);
+
+ if (high_pfn < size || new_pfn < low_pfn) {
+ if (low_pfn == iovad->start_pfn && retry_pfn < limit_pfn) {
+ high_pfn = limit_pfn;
+ low_pfn = retry_pfn;
+ curr = iova_find_limit(iovad, limit_pfn);
+ curr_iova = to_iova(curr);
+ goto retry;
+ }
+ iovad->max32_alloc_size = size;
+ goto iova32_full;
+ }
+
+ /* pfn_lo will point to size aligned address if size_aligned is set */
+ new->pfn_lo = new_pfn;
+ new->pfn_hi = new->pfn_lo + size - 1;
+
+ /* If we have 'prev', it's a valid place to start the insertion. */
+ iova_insert_rbtree(&iovad->rbroot, new, prev);
+ __cached_rbnode_insert_update(iovad, new);
+
+ spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+ return 0;
+
+iova32_full:
+ spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+ return -ENOMEM;
+}
+
/**
* find_iova - finds an iova for a given pfn
* @iovad: - iova domain in question.
@@ -377,6 +375,41 @@ struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn)
}
EXPORT_SYMBOL_GPL(find_iova);
+/**
+ * alloc_iova - allocates an iova
+ * @iovad: - iova domain in question
+ * @size: - size of page frames to allocate
+ * @limit_pfn: - max limit address
+ * @size_aligned: - set if size_aligned address range is required
+ * This function allocates an iova in the range iovad->start_pfn to limit_pfn,
+ * searching top-down from limit_pfn to iovad->start_pfn. If the size_aligned
+ * flag is set then the allocated address iova->pfn_lo will be naturally
+ * aligned on roundup_power_of_two(size).
+ */
+struct iova *
+alloc_iova(struct iova_domain *iovad, unsigned long size,
+ unsigned long limit_pfn,
+ bool size_aligned)
+{
+ struct iova *new_iova;
+ int ret;
+
+ new_iova = alloc_iova_mem();
+ if (!new_iova)
+ return NULL;
+
+ ret = __alloc_and_insert_iova_range(iovad, size, limit_pfn + 1,
+ new_iova, size_aligned);
+
+ if (ret) {
+ free_iova_mem(new_iova);
+ return NULL;
+ }
+
+ return new_iova;
+}
+EXPORT_SYMBOL_GPL(alloc_iova);
+
/**
* __free_iova - frees the given iova
* @iovad: iova domain in question.
@@ -420,234 +453,51 @@ free_iova(struct iova_domain *iovad, unsigned long pfn)
}
EXPORT_SYMBOL_GPL(free_iova);
-/**
- * alloc_iova_fast - allocates an iova from rcache
- * @iovad: - iova domain in question
- * @size: - size of page frames to allocate
- * @limit_pfn: - max limit address
- * @flush_rcache: - set to flush rcache on regular allocation failure
- * This function tries to satisfy an iova allocation from the rcache,
- * and falls back to regular allocation on failure. If regular allocation
- * fails too and the flush_rcache flag is set then the rcache will be flushed.
-*/
-unsigned long
-alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
- unsigned long limit_pfn, bool flush_rcache)
+static bool iova_magazine_full(struct iova_magazine *mag)
{
- unsigned long iova_pfn;
- struct iova *new_iova;
-
- /*
- * Freeing non-power-of-two-sized allocations back into the IOVA caches
- * will come back to bite us badly, so we have to waste a bit of space
- * rounding up anything cacheable to make sure that can't happen. The
- * order of the unadjusted size will still match upon freeing.
- */
- if (size < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1)))
- size = roundup_pow_of_two(size);
-
- iova_pfn = iova_rcache_get(iovad, size, limit_pfn + 1);
- if (iova_pfn)
- return iova_pfn;
-
-retry:
- new_iova = alloc_iova(iovad, size, limit_pfn, true);
- if (!new_iova) {
- unsigned int cpu;
+ return (mag && mag->size == IOVA_MAG_SIZE);
+}
- if (!flush_rcache)
- return 0;
+static void iova_magazine_push(struct iova_magazine *mag, unsigned long pfn)
+{
+ BUG_ON(iova_magazine_full(mag));
- /* 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;
- }
+ mag->pfns[mag->size++] = pfn;
+}
- return new_iova->pfn_lo;
+static struct iova_magazine *iova_magazine_alloc(gfp_t flags)
+{
+ return kzalloc(sizeof(struct iova_magazine), flags);
}
-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)
+static void iova_magazine_free(struct iova_magazine *mag)
{
- struct iova *iova;
-
- iova = alloc_and_init_iova(pfn_lo, pfn_hi);
- if (iova)
- iova_insert_rbtree(&iovad->rbroot, iova, NULL);
-
- return iova;
+ kfree(mag);
}
-static void
-__adjust_overlap_range(struct iova *iova,
- unsigned long *pfn_lo, unsigned long *pfn_hi)
+static bool iova_magazine_empty(struct iova_magazine *mag)
{
- if (*pfn_lo < iova->pfn_lo)
- iova->pfn_lo = *pfn_lo;
- if (*pfn_hi > iova->pfn_hi)
- *pfn_lo = iova->pfn_hi + 1;
+ return (!mag || mag->size == 0);
}
-/**
- * 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)
+static unsigned long iova_magazine_pop(struct iova_magazine *mag,
+ unsigned long limit_pfn)
{
- struct rb_node *node;
- unsigned long flags;
- struct iova *iova;
- unsigned int overlap = 0;
-
- /* Don't allow nonsensical pfns */
- if (WARN_ON((pfn_hi | pfn_lo) > (ULLONG_MAX >> iova_shift(iovad))))
- return NULL;
-
- spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
- for (node = rb_first(&iovad->rbroot); node; node = rb_next(node)) {
- if (__is_range_overlap(node, pfn_lo, pfn_hi)) {
- iova = to_iova(node);
- __adjust_overlap_range(iova, &pfn_lo, &pfn_hi);
- if ((pfn_lo >= iova->pfn_lo) &&
- (pfn_hi <= iova->pfn_hi))
- goto finish;
- overlap = 1;
-
- } else if (overlap)
- break;
- }
-
- /* We are here either because this is the first reserver node
- * or need to insert remaining non overlap addr range
- */
- iova = __insert_new_range(iovad, pfn_lo, pfn_hi);
-finish:
-
- spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
- return iova;
-}
-EXPORT_SYMBOL_GPL(reserve_iova);
-
-/*
- * Magazine caches for IOVA ranges. For an introduction to magazines,
- * see the USENIX 2001 paper "Magazines and Vmem: Extending the Slab
- * Allocator to Many CPUs and Arbitrary Resources" by Bonwick and Adams.
- * For simplicity, we use a static magazine size and don't implement the
- * dynamic size tuning described in the paper.
- */
-
-/*
- * As kmalloc's buffer size is fixed to power of 2, 127 is chosen to
- * assure size of 'iova_magazine' to be 1024 bytes, so that no memory
- * will be wasted.
- */
-#define IOVA_MAG_SIZE 127
-#define MAX_GLOBAL_MAGS 32 /* magazines per bin */
-
-struct iova_magazine {
- unsigned long size;
- unsigned long pfns[IOVA_MAG_SIZE];
-};
+ int i;
+ unsigned long pfn;
-struct iova_cpu_rcache {
- spinlock_t lock;
- struct iova_magazine *loaded;
- struct iova_magazine *prev;
-};
+ BUG_ON(iova_magazine_empty(mag));
-struct iova_rcache {
- spinlock_t lock;
- unsigned long depot_size;
- struct iova_magazine *depot[MAX_GLOBAL_MAGS];
- struct iova_cpu_rcache __percpu *cpu_rcaches;
-};
+ /* 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;
-static struct iova_magazine *iova_magazine_alloc(gfp_t flags)
-{
- return kzalloc(sizeof(struct iova_magazine), flags);
-}
+ /* Swap it to pop it */
+ pfn = mag->pfns[i];
+ mag->pfns[i] = mag->pfns[--mag->size];
-static void iova_magazine_free(struct iova_magazine *mag)
-{
- kfree(mag);
+ return pfn;
}
static void
@@ -676,91 +526,91 @@ iova_magazine_free_pfns(struct iova_magazine *mag, struct iova_domain *iovad)
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)
+/*
+ * 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;
- 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;
+ 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);
+ }
}
-static void iova_magazine_push(struct iova_magazine *mag, unsigned long pfn)
+static int iova_cpuhp_dead(unsigned int cpu, struct hlist_node *node)
{
- BUG_ON(iova_magazine_full(mag));
+ struct iova_domain *iovad;
- mag->pfns[mag->size++] = pfn;
+ iovad = hlist_entry_safe(node, struct iova_domain, cpuhp_dead);
+
+ free_cpu_cached_iovas(cpu, iovad);
+ return 0;
}
-int iova_domain_init_rcaches(struct iova_domain *iovad)
+/*
+ * free all the IOVA ranges of global cache
+ */
+static void free_global_cached_iovas(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;
+ struct iova_rcache *rcache;
+ unsigned long flags;
+ int i, j;
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;
+ 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]);
}
- for_each_possible_cpu(cpu) {
- cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
+ rcache->depot_size = 0;
+ spin_unlock_irqrestore(&rcache->lock, flags);
+ }
+}
- 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;
- }
+/*
+ * 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]);
}
- ret = cpuhp_state_add_instance_nocalls(CPUHP_IOMMU_IOVA_DEAD,
- &iovad->cpuhp_dead);
- if (ret)
- goto out_err;
- return 0;
+ kfree(iovad->rcaches);
+ iovad->rcaches = NULL;
+}
-out_err:
+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);
- return ret;
}
-EXPORT_SYMBOL_GPL(iova_domain_init_rcaches);
/*
* Try inserting IOVA range starting with 'iova_pfn' into 'rcache', and
@@ -883,73 +733,212 @@ static unsigned long iova_rcache_get(struct iova_domain *iovad,
return __iova_rcache_get(&iovad->rcaches[log_size], limit_pfn - size);
}
-/*
- * free rcache data structures.
+/**
+ * alloc_iova_fast - allocates an iova from rcache
+ * @iovad: - iova domain in question
+ * @size: - size of page frames to allocate
+ * @limit_pfn: - max limit address
+ * @flush_rcache: - set to flush rcache on regular allocation failure
+ * This function tries to satisfy an iova allocation from the rcache,
+ * and falls back to regular allocation on failure. If regular allocation
+ * fails too and the flush_rcache flag is set then the rcache will be flushed.
*/
-static void free_iova_rcaches(struct iova_domain *iovad)
+unsigned long
+alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
+ unsigned long limit_pfn, bool flush_rcache)
+{
+ unsigned long iova_pfn;
+ struct iova *new_iova;
+
+ /*
+ * Freeing non-power-of-two-sized allocations back into the IOVA caches
+ * will come back to bite us badly, so we have to waste a bit of space
+ * rounding up anything cacheable to make sure that can't happen. The
+ * order of the unadjusted size will still match upon freeing.
+ */
+ if (size < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1)))
+ size = roundup_pow_of_two(size);
+
+ iova_pfn = iova_rcache_get(iovad, size, limit_pfn + 1);
+ if (iova_pfn)
+ return iova_pfn;
+
+retry:
+ new_iova = alloc_iova(iovad, size, limit_pfn, true);
+ if (!new_iova) {
+ unsigned int cpu;
+
+ if (!flush_rcache)
+ return 0;
+
+ /* Try replenishing IOVAs by flushing rcache. */
+ flush_rcache = false;
+ for_each_online_cpu(cpu)
+ free_cpu_cached_iovas(cpu, iovad);
+ free_global_cached_iovas(iovad);
+ goto retry;
+ }
+
+ return new_iova->pfn_lo;
+}
+EXPORT_SYMBOL_GPL(alloc_iova_fast);
+
+/**
+ * free_iova_fast - free iova pfn range into rcache
+ * @iovad: - iova domain in question.
+ * @pfn: - pfn that is allocated previously
+ * @size: - # of pages in range
+ * This functions frees an iova range by trying to put it into the rcache,
+ * falling back to regular iova deallocation via free_iova() if this fails.
+ */
+void
+free_iova_fast(struct iova_domain *iovad, unsigned long pfn, unsigned long size)
+{
+ if (iova_rcache_insert(iovad, pfn, size))
+ return;
+
+ free_iova(iovad, pfn);
+}
+EXPORT_SYMBOL_GPL(free_iova_fast);
+
+int iova_domain_init_rcaches(struct iova_domain *iovad)
{
- struct iova_rcache *rcache;
- struct iova_cpu_rcache *cpu_rcache;
unsigned int cpu;
- int i, j;
+ 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];
- if (!rcache->cpu_rcaches)
- break;
+ 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);
- iova_magazine_free(cpu_rcache->loaded);
- iova_magazine_free(cpu_rcache->prev);
+
+ 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;
+ }
}
- 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;
+ 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);
-/*
- * 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)
+void
+init_iova_domain(struct iova_domain *iovad, unsigned long granule,
+ unsigned long start_pfn)
{
- struct iova_cpu_rcache *cpu_rcache;
- struct iova_rcache *rcache;
- unsigned long flags;
- int i;
+ /*
+ * IOVA granularity will normally be equal to the smallest
+ * supported IOMMU page size; both *must* be capable of
+ * representing individual CPU pages exactly.
+ */
+ BUG_ON((granule > PAGE_SIZE) || !is_power_of_2(granule));
- 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);
- }
+ spin_lock_init(&iovad->iova_rbtree_lock);
+ iovad->rbroot = RB_ROOT;
+ iovad->cached_node = &iovad->anchor.node;
+ iovad->cached32_node = &iovad->anchor.node;
+ iovad->granule = granule;
+ iovad->start_pfn = start_pfn;
+ iovad->dma_32bit_pfn = 1UL << (32 - iova_shift(iovad));
+ iovad->max32_alloc_size = iovad->dma_32bit_pfn;
+ iovad->anchor.pfn_lo = iovad->anchor.pfn_hi = IOVA_ANCHOR;
+ rb_link_node(&iovad->anchor.node, NULL, &iovad->rbroot.rb_node);
+ rb_insert_color(&iovad->anchor.node, &iovad->rbroot);
}
+EXPORT_SYMBOL_GPL(init_iova_domain);
-/*
- * free all the IOVA ranges of global cache
+/**
+ * put_iova_domain - destroys the iova domain
+ * @iovad: - iova domain in question.
+ * All the iova's in that domain are destroyed.
*/
-static void free_global_cached_iovas(struct iova_domain *iovad)
+void put_iova_domain(struct iova_domain *iovad)
{
- struct iova_rcache *rcache;
- unsigned long flags;
- int i, j;
+ struct iova *iova, *tmp;
- 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]);
+ 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);
+
+int iova_cache_get(void)
+{
+ mutex_lock(&iova_cache_mutex);
+ if (!iova_cache_users) {
+ int ret;
+
+ ret = cpuhp_setup_state_multi(CPUHP_IOMMU_IOVA_DEAD, "iommu/iova:dead", NULL,
+ iova_cpuhp_dead);
+ if (ret) {
+ mutex_unlock(&iova_cache_mutex);
+ pr_err("Couldn't register cpuhp handler\n");
+ return ret;
}
- rcache->depot_size = 0;
- spin_unlock_irqrestore(&rcache->lock, flags);
+
+ iova_cache = kmem_cache_create(
+ "iommu_iova", sizeof(struct iova), 0,
+ SLAB_HWCACHE_ALIGN, NULL);
+ if (!iova_cache) {
+ cpuhp_remove_multi_state(CPUHP_IOMMU_IOVA_DEAD);
+ mutex_unlock(&iova_cache_mutex);
+ pr_err("Couldn't create iova cache\n");
+ return -ENOMEM;
+ }
+ }
+
+ iova_cache_users++;
+ mutex_unlock(&iova_cache_mutex);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(iova_cache_get);
+
+void iova_cache_put(void)
+{
+ mutex_lock(&iova_cache_mutex);
+ if (WARN_ON(!iova_cache_users)) {
+ mutex_unlock(&iova_cache_mutex);
+ return;
}
+ iova_cache_users--;
+ if (!iova_cache_users) {
+ cpuhp_remove_multi_state(CPUHP_IOMMU_IOVA_DEAD);
+ kmem_cache_destroy(iova_cache);
+ }
+ mutex_unlock(&iova_cache_mutex);
}
+EXPORT_SYMBOL_GPL(iova_cache_put);
+
MODULE_AUTHOR("Anil S Keshavamurthy <anil.s.keshavamurthy@xxxxxxxxx>");
MODULE_LICENSE("GPL");
diff --git a/include/linux/iova.h b/include/linux/iova.h
index 320a70e40233..a167fb22c899 100644
--- a/include/linux/iova.h
+++ b/include/linux/iova.h
@@ -76,35 +76,26 @@ static inline unsigned long iova_pfn(struct iova_domain *iovad, dma_addr_t iova)
}
#if IS_ENABLED(CONFIG_IOMMU_IOVA)
-int iova_cache_get(void);
-void iova_cache_put(void);
-
void free_iova(struct iova_domain *iovad, unsigned long pfn);
void __free_iova(struct iova_domain *iovad, struct iova *iova);
struct iova *alloc_iova(struct iova_domain *iovad, unsigned long size,
unsigned long limit_pfn,
bool size_aligned);
+struct iova *reserve_iova(struct iova_domain *iovad, unsigned long pfn_lo,
+ unsigned long pfn_hi);
+struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn);
void free_iova_fast(struct iova_domain *iovad, unsigned long pfn,
unsigned long size);
unsigned long alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
unsigned long limit_pfn, bool flush_rcache);
-struct iova *reserve_iova(struct iova_domain *iovad, unsigned long pfn_lo,
- unsigned long pfn_hi);
+int iova_domain_init_rcaches(struct iova_domain *iovad);
void init_iova_domain(struct iova_domain *iovad, unsigned long granule,
unsigned long start_pfn);
-int iova_domain_init_rcaches(struct iova_domain *iovad);
-struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn);
void put_iova_domain(struct iova_domain *iovad);
-#else
-static inline int iova_cache_get(void)
-{
- return -ENOTSUPP;
-}
-
-static inline void iova_cache_put(void)
-{
-}
+int iova_cache_get(void);
+void iova_cache_put(void);
+#else
static inline void free_iova(struct iova_domain *iovad, unsigned long pfn)
{
}
@@ -121,6 +112,19 @@ static inline struct iova *alloc_iova(struct iova_domain *iovad,
return NULL;
}
+static inline struct iova *reserve_iova(struct iova_domain *iovad,
+ unsigned long pfn_lo,
+ unsigned long pfn_hi)
+{
+ return NULL;
+}
+
+static inline struct iova *find_iova(struct iova_domain *iovad,
+ unsigned long pfn)
+{
+ return NULL;
+}
+
static inline void free_iova_fast(struct iova_domain *iovad,
unsigned long pfn,
unsigned long size)
@@ -135,12 +139,6 @@ static inline unsigned long alloc_iova_fast(struct iova_domain *iovad,
return 0;
}
-static inline struct iova *reserve_iova(struct iova_domain *iovad,
- unsigned long pfn_lo,
- unsigned long pfn_hi)
-{
- return NULL;
-}
static inline void init_iova_domain(struct iova_domain *iovad,
unsigned long granule,
@@ -148,13 +146,17 @@ static inline void init_iova_domain(struct iova_domain *iovad,
{
}
-static inline struct iova *find_iova(struct iova_domain *iovad,
- unsigned long pfn)
+
+static inline void put_iova_domain(struct iova_domain *iovad)
{
- return NULL;
}
-static inline void put_iova_domain(struct iova_domain *iovad)
+static inline int iova_cache_get(void)
+{
+ return -ENOTSUPP;
+}
+
+static inline void iova_cache_put(void)
{
}