Looks very nice! Inline comments.
On Wed, Apr 13, 2016 at 11:52 AM, Adam Morrison <[email protected]> wrote:
> From: Omer Peleg <[email protected]>
>
> IOVA allocation has two problems that impede high-throughput I/O.
> First, it can do a linear search over the allocated IOVA ranges.
> Second, the rbtree spinlock that serializes IOVA allocations becomes
> contended.
>
> Address these problems by creating an API for caching allocated IOVA
> ranges, so that the IOVA allocator isn't accessed frequently. This
> patch adds a per-CPU cache, from which CPUs can alloc/free IOVAs
> without taking the rbtree spinlock. The per-CPU caches are backed by
> a global cache, to avoid invoking the (linear-time) IOVA allocator
> without needing to make the per-CPU cache size excessive. This design
> is based on magazines, as described in "Magazines and Vmem: Extending
> the Slab Allocator to Many CPUs and Arbitrary Resources" (currently
> available at https://www.usenix.org/legacy/event/usenix01/bonwick.html)
>
> Adding caching on top of the existing rbtree allocator maintains the
> property that IOVAs are densely packed in the IO virtual address space,
> which is important for keeping IOMMU page table usage low.
>
> To keep the cache size reasonable, we limit caching to ranges of
> size <= 128 KB. Overall, a CPU can cache at most 32 MB and the global
> cache is bounded by 4 MB.
>
> Signed-off-by: Omer Peleg <[email protected]>
> [[email protected]: rebased, cleaned up and reworded the commit message]
> Signed-off-by: Adam Morrison <[email protected]>
> ---
> drivers/iommu/intel-iommu.c | 47 ++++--
> drivers/iommu/iova.c | 372
> +++++++++++++++++++++++++++++++++++++++++---
> include/linux/iova.h | 23 ++-
> 3 files changed, 404 insertions(+), 38 deletions(-)
>
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index 7a9a3a6..629c5b19 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -3357,7 +3357,7 @@ static unsigned long intel_alloc_iova(struct device
> *dev,
> struct dmar_domain *domain,
> unsigned long nrpages, uint64_t dma_mask)
> {
> - struct iova *iova = NULL;
> + unsigned long iova_pfn = 0;
>
> /* Restrict dma_mask to the width that the iommu can handle */
> dma_mask = min_t(uint64_t, DOMAIN_MAX_ADDR(domain->gaw), dma_mask);
> @@ -3370,19 +3370,19 @@ static unsigned long intel_alloc_iova(struct device
> *dev,
> * DMA_BIT_MASK(32) and if that fails then try allocating
> * from higher range
> */
> - iova = alloc_iova(&domain->iovad, nrpages,
> - IOVA_PFN(DMA_BIT_MASK(32)), 1);
> - if (iova)
> - return iova->pfn_lo;
> + iova_pfn = alloc_iova_fast(&domain->iovad, nrpages,
> + IOVA_PFN(DMA_BIT_MASK(32)));
> + if (iova_pfn)
> + return iova_pfn;
> }
> - iova = alloc_iova(&domain->iovad, nrpages, IOVA_PFN(dma_mask), 1);
> - if (unlikely(!iova)) {
> + iova_pfn = alloc_iova_fast(&domain->iovad, nrpages,
> IOVA_PFN(dma_mask));
> + if (unlikely(!iova_pfn)) {
> pr_err("Allocating %ld-page iova for %s failed",
> nrpages, dev_name(dev));
> return 0;
> }
>
> - return iova->pfn_lo;
> + return iova_pfn;
> }
>
> static struct dmar_domain *__get_valid_domain_for_dev(struct device *dev)
> @@ -3536,7 +3536,7 @@ static dma_addr_t __intel_map_single(struct device
> *dev, phys_addr_t paddr,
>
> error:
> if (iova_pfn)
> - free_iova(&domain->iovad, iova_pfn);
> + free_iova_fast(&domain->iovad, iova_pfn, dma_to_mm_pfn(size));
> pr_err("Device %s request: %zx@%llx dir %d --- failed\n",
> dev_name(dev), size, (unsigned long long)paddr, dir);
> return 0;
> @@ -3591,7 +3591,7 @@ static void flush_unmaps(struct deferred_flush_data
> *flush_data)
> iommu_flush_dev_iotlb(domain,
> (uint64_t)iova_pfn <<
> PAGE_SHIFT, mask);
> }
> - free_iova(&domain->iovad, iova_pfn);
> + free_iova_fast(&domain->iovad, iova_pfn, nrpages);
> if (freelist)
> dma_free_pagelist(freelist);
> }
> @@ -3691,7 +3691,7 @@ static void intel_unmap(struct device *dev, dma_addr_t
> dev_addr, size_t size)
> iommu_flush_iotlb_psi(iommu, domain, start_pfn,
> nrpages, !freelist, 0);
> /* free iova */
> - free_iova(&domain->iovad, iova_pfn);
> + free_iova_fast(&domain->iovad, iova_pfn,
> dma_to_mm_pfn(nrpages));
> dma_free_pagelist(freelist);
> } else {
> add_unmap(domain, iova_pfn, nrpages, freelist);
> @@ -3849,7 +3849,7 @@ static int intel_map_sg(struct device *dev, struct
> scatterlist *sglist, int nele
> if (unlikely(ret)) {
> dma_pte_free_pagetable(domain, start_vpfn,
> start_vpfn + size - 1);
> - free_iova(&domain->iovad, iova_pfn);
> + free_iova_fast(&domain->iovad, iova_pfn, dma_to_mm_pfn(size));
> return 0;
> }
>
> @@ -4588,6 +4588,28 @@ static struct notifier_block intel_iommu_memory_nb = {
> .priority = 0
> };
>
> +static void free_all_cpu_cached_iovas(unsigned int cpu)
> +{
> + int i;
> +
> + for (i = 0; i < g_num_of_iommus; i++) {
> + struct intel_iommu *iommu = g_iommus[i];
> + struct dmar_domain *domain;
> + u16 did;
> +
> + if (!iommu)
> + continue;
> +
> + for (did = 0; did < 0xffff; did++) {
> + domain = get_iommu_domain(iommu, did);
> +
> + if (!domain)
> + continue;
> + free_cpu_cached_iovas(cpu, &domain->iovad);
> + }
> + }
> +}
> +
> static int intel_iommu_cpu_notifier(struct notifier_block *nfb,
> unsigned long action, void *v)
> {
> @@ -4596,6 +4618,7 @@ static int intel_iommu_cpu_notifier(struct
> notifier_block *nfb,
> switch (action) {
> case CPU_DEAD:
> case CPU_DEAD_FROZEN:
> + free_all_cpu_cached_iovas(cpu);
> flush_unmaps_timeout(cpu);
> break;
> }
> diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
> index fa0adef..db3b914 100644
> --- a/drivers/iommu/iova.c
> +++ b/drivers/iommu/iova.c
> @@ -20,6 +20,16 @@
> #include <linux/iova.h>
> #include <linux/module.h>
> #include <linux/slab.h>
> +#include <linux/smp.h>
> +#include <linux/bitops.h>
> +
> +static bool iova_rcache_insert(struct iova_domain *iovad,
> + struct iova_rcache *rcache,
> + unsigned long iova_pfn);
> +static unsigned long iova_rcache_get(struct iova_rcache *rcache);
> +
> +static void init_iova_rcaches(struct iova_domain *iovad);
> +static void free_iova_rcaches(struct iova_domain *iovad);
>
> void
> init_iova_domain(struct iova_domain *iovad, unsigned long granule,
> @@ -38,6 +48,7 @@ init_iova_domain(struct iova_domain *iovad, unsigned long
> granule,
> iovad->granule = granule;
> iovad->start_pfn = start_pfn;
> iovad->dma_32bit_pfn = pfn_32bit;
> + init_iova_rcaches(iovad);
> }
> EXPORT_SYMBOL_GPL(init_iova_domain);
>
> @@ -291,33 +302,18 @@ alloc_iova(struct iova_domain *iovad, unsigned long
> size,
> }
> EXPORT_SYMBOL_GPL(alloc_iova);
>
> -/**
> - * find_iova - find's an iova for a given pfn
> - * @iovad: - iova domain in question.
> - * @pfn: - page frame number
> - * This function finds and returns an iova belonging to the
> - * given doamin which matches the given pfn.
> - */
> -struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn)
> +static struct iova *
> +private_find_iova(struct iova_domain *iovad, unsigned long pfn)
> {
> - unsigned long flags;
> - struct rb_node *node;
> + struct rb_node *node = iovad->rbroot.rb_node;
> +
> + assert_spin_locked(&iovad->iova_rbtree_lock);
>
> - /* Take the lock so that no other thread is manipulating the rbtree */
> - spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
> - node = iovad->rbroot.rb_node;
> while (node) {
> struct iova *iova = container_of(node, struct iova, node);
>
> /* If pfn falls within iova's range, return iova */
> if ((pfn >= iova->pfn_lo) && (pfn <= iova->pfn_hi)) {
> - spin_unlock_irqrestore(&iovad->iova_rbtree_lock,
> flags);
> - /* We are not holding the lock while this iova
> - * is referenced by the caller as the same thread
> - * which called this function also calls __free_iova()
> - * and it is by design that only one thread can
> possibly
> - * reference a particular iova and hence no conflict.
> - */
> return iova;
> }
>
> @@ -327,9 +323,35 @@ struct iova *find_iova(struct iova_domain *iovad,
> unsigned long pfn)
> node = node->rb_right;
> }
>
> - spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
> return NULL;
> }
> +
> +static void private_free_iova(struct iova_domain *iovad, struct iova *iova)
> +{
> + assert_spin_locked(&iovad->iova_rbtree_lock);
> + __cached_rbnode_delete_update(iovad, iova);
> + rb_erase(&iova->node, &iovad->rbroot);
> + free_iova_mem(iova);
> +}
> +
> +/**
> + * find_iova - finds an iova for a given pfn
> + * @iovad: - iova domain in question.
> + * @pfn: - page frame number
> + * This function finds and returns an iova belonging to the
> + * given doamin which matches the given pfn.
> + */
> +struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn)
> +{
> + unsigned long flags;
> + struct iova *iova;
> +
> + /* Take the lock so that no other thread is manipulating the rbtree */
> + spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
> + iova = private_find_iova(iovad, pfn);
> + spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
> + return iova;
> +}
> EXPORT_SYMBOL_GPL(find_iova);
>
> /**
> @@ -344,10 +366,8 @@ __free_iova(struct iova_domain *iovad, struct iova *iova)
> unsigned long flags;
>
> spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
> - __cached_rbnode_delete_update(iovad, iova);
> - rb_erase(&iova->node, &iovad->rbroot);
> + private_free_iova(iovad, iova);
> spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
> - free_iova_mem(iova);
> }
> EXPORT_SYMBOL_GPL(__free_iova);
>
> @@ -370,6 +390,57 @@ 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
> + * This function tries to satisfy an iova allocation from the rcache,
> + * and falls back to regular allocation on failure.
> +*/
> +unsigned long
> +alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
> + unsigned long limit_pfn)
> +{
> + unsigned int log_size = fls_long(size - 1);
In free_iova_fast, order_base_2(size) is used. Why differ here?
> + unsigned long iova_pfn;
> + struct iova *new_iova;
> +
> + if (log_size < IOVA_RANGE_CACHE_MAX_SIZE) {
> + iova_pfn = iova_rcache_get(&iovad->rcaches[log_size]);
> + if (iova_pfn)
> + return iova_pfn;
> + }
> +
> + new_iova = alloc_iova(iovad, size, limit_pfn, true);
> + if (!new_iova)
> + return 0;
It was pointed out that DMA_32 or _24 (or anything other non-64 size)
could be starved if the magazines on all cores are full and the depot
is empty. (This gets more probable with increased core count.) You
could try one more time: call free_iova_rcaches() and try alloc_iova
again before giving up
> +
> + 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)
> +{
> + unsigned int log_size = order_base_2(size);
> +
> + if (log_size < IOVA_RANGE_CACHE_MAX_SIZE &&
> + iova_rcache_insert(iovad, &iovad->rcaches[log_size], pfn))
> + return;
> +
> + free_iova(iovad, pfn);
> +}
> +EXPORT_SYMBOL_GPL(free_iova_fast);
> +
> +/**
> * put_iova_domain - destroys the iova doamin
> * @iovad: - iova domain in question.
> * All the iova's in that domain are destroyed.
> @@ -379,6 +450,7 @@ void put_iova_domain(struct iova_domain *iovad)
> struct rb_node *node;
> unsigned long flags;
>
> + free_iova_rcaches(iovad);
> spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
> node = rb_first(&iovad->rbroot);
> while (node) {
> @@ -550,5 +622,257 @@ error:
> return NULL;
> }
>
> +/*
> + * Magazine caches for IOVA ranges. For an introduction to magazines,
> + * see the USENIX 2001 paper "Magazines and Vmem: Extending the Slab
> + * Allocator to Many CPUs and Arbitrary Resources" by Bonwick and Adams.
> + * For simplicity, we use a static magazine size and don't implement the
> + * dynamic size tuning described in the paper.
> + */
> +
> +#define IOVA_MAG_SIZE 128
> +
> +struct iova_magazine {
> + unsigned long size;
> + unsigned long pfns[IOVA_MAG_SIZE];
> +};
> +
> +struct iova_cpu_rcache {
> + struct iova_magazine *loaded;
> + struct iova_magazine *prev;
> +};
> +
> +static struct iova_magazine *iova_magazine_alloc(gfp_t flags)
> +{
> + return kzalloc(sizeof(struct iova_magazine), flags);
> +}
> +
> +static void iova_magazine_free(struct iova_magazine *mag)
> +{
> + kfree(mag);
> +}
> +
> +static void
> +iova_magazine_free_pfns(struct iova_magazine *mag, struct iova_domain *iovad)
> +{
> + unsigned long flags;
> + int i;
> +
> + if (!mag)
> + return;
> +
> + spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
> +
> + for (i = 0 ; i < mag->size; ++i) {
> + struct iova *iova = private_find_iova(iovad, mag->pfns[i]);
> +
> + BUG_ON(!iova);
> + private_free_iova(iovad, iova);
> + }
> +
> + spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
> +
> + mag->size = 0;
> +}
> +
> +static bool iova_magazine_full(struct iova_magazine *mag)
> +{
> + return (mag && mag->size == IOVA_MAG_SIZE);
> +}
> +
> +static bool iova_magazine_empty(struct iova_magazine *mag)
> +{
> + return (!mag || mag->size == 0);
> +}
> +
> +static unsigned long iova_magazine_pop(struct iova_magazine *mag)
> +{
> + BUG_ON(iova_magazine_empty(mag));
> +
> + return mag->pfns[--mag->size];
> +}
> +
> +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);
> + 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;
> +
> + preempt_disable();
> + cpu_rcache = this_cpu_ptr(rcache->cpu_rcaches);
> +
> + 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) {
> + unsigned long flags;
> +
> + spin_lock_irqsave(&rcache->lock, flags);
> + if (rcache->depot_size < MAX_GLOBAL_MAGS) {
> + rcache->depot[rcache->depot_size++] =
> + cpu_rcache->loaded;
> + } else {
> + mag_to_free = cpu_rcache->loaded;
> + }
> + spin_unlock_irqrestore(&rcache->lock, flags);
> +
> + cpu_rcache->loaded = new_mag;
> + can_insert = true;
> + }
> + }
> +
> + if (can_insert)
> + iova_magazine_push(cpu_rcache->loaded, iova_pfn);
> +
> + preempt_enable();
> +
> + if (mag_to_free) {
> + iova_magazine_free_pfns(mag_to_free, iovad);
> + iova_magazine_free(mag_to_free);
> + }
> +
> + return can_insert;
> +}
> +
> +/*
> + * 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)
> +{
> + struct iova_cpu_rcache *cpu_rcache;
> + unsigned long iova_pfn = 0;
> + bool has_pfn = false;
> +
> + preempt_disable();
> + cpu_rcache = this_cpu_ptr(rcache->cpu_rcaches);
> +
> + 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 {
> + unsigned long flags;
> +
> + spin_lock_irqsave(&rcache->lock, flags);
> + if (rcache->depot_size > 0) {
> + iova_magazine_free(cpu_rcache->loaded);
> + cpu_rcache->loaded =
> rcache->depot[--rcache->depot_size];
> + has_pfn = true;
> + }
> + spin_unlock_irqrestore(&rcache->lock, flags);
> + }
> +
> + if (has_pfn)
> + iova_pfn = iova_magazine_pop(cpu_rcache->loaded);
> +
> + preempt_enable();
> +
> + return iova_pfn;
> +}
> +
> +/*
> + * free a cpu's rcache; assumes it cannot race with the cpu accessing
> + * its rcache.
> + */
> +static void free_cpu_iova_rcache(unsigned int cpu, struct iova_domain *iovad,
> + struct iova_rcache *rcache)
> +{
> + struct iova_cpu_rcache *cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches,
> cpu);
> +
> + /* No one else touches cpu caches when they're freed */
> + iova_magazine_free_pfns(cpu_rcache->loaded, iovad);
> + iova_magazine_free(cpu_rcache->loaded);
> +
> + iova_magazine_free_pfns(cpu_rcache->prev, iovad);
> + iova_magazine_free(cpu_rcache->prev);
> +}
> +
> +/*
> + * reset entire rcache data structure.
> + */
> +static void free_iova_rcaches(struct iova_domain *iovad)
> +{
> + struct iova_rcache *rcache;
> + unsigned long flags;
> + 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)
> + free_cpu_iova_rcache(cpu, iovad, rcache);
> + spin_lock_irqsave(&rcache->lock, flags);
> + free_percpu(rcache->cpu_rcaches);
> + for (j = 0; j < rcache->depot_size; ++j) {
> + iova_magazine_free_pfns(rcache->depot[j], iovad);
> + iova_magazine_free(rcache->depot[j]);
> + }
> + spin_unlock_irqrestore(&rcache->lock, flags);
> + }
> +}
> +
> +/*
> + * free all the IOVA ranges cached by a cpu (used when cpu is unplugged)
> + */
> +void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad)
> +{
> + struct iova_cpu_rcache *cpu_rcache;
> + struct iova_rcache *rcache;
> + 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);
> + iova_magazine_free_pfns(cpu_rcache->loaded, iovad);
> + iova_magazine_free_pfns(cpu_rcache->prev, iovad);
> + }
> +}
> +
> +
> MODULE_AUTHOR("Anil S Keshavamurthy <[email protected]>");
> MODULE_LICENSE("GPL");
> diff --git a/include/linux/iova.h b/include/linux/iova.h
> index 92f7177..0652cdd 100644
> --- a/include/linux/iova.h
> +++ b/include/linux/iova.h
> @@ -19,8 +19,21 @@
> /* iova structure */
> struct iova {
> struct rb_node node;
> - unsigned long pfn_hi; /* IOMMU dish out addr hi */
> - unsigned long pfn_lo; /* IOMMU dish out addr lo */
> + unsigned long pfn_hi; /* Highest allocated pfn */
> + unsigned long pfn_lo; /* Lowest allocated pfn */
> +};
> +
> +struct iova_magazine;
> +struct iova_cpu_rcache;
> +
> +#define IOVA_RANGE_CACHE_MAX_SIZE 6 /* log of max cached IOVA range size
> (in pages) */
> +#define MAX_GLOBAL_MAGS 32 /* magazines per bin */
> +
> +struct iova_rcache {
> + spinlock_t lock;
> + int depot_size;
> + struct iova_magazine *depot[MAX_GLOBAL_MAGS];
> + struct iova_cpu_rcache __percpu *cpu_rcaches;
> };
>
> /* holds all the iova translations for a domain */
> @@ -31,6 +44,7 @@ struct iova_domain {
> unsigned long granule; /* pfn granularity for this domain */
> unsigned long start_pfn; /* Lower limit for this domain */
> unsigned long dma_32bit_pfn;
> + struct iova_rcache rcaches[IOVA_RANGE_CACHE_MAX_SIZE]; /* IOVA range
> caches */
> };
>
> static inline unsigned long iova_size(struct iova *iova)
> @@ -78,6 +92,10 @@ 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);
> +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);
> struct iova *reserve_iova(struct iova_domain *iovad, unsigned long pfn_lo,
> unsigned long pfn_hi);
> void copy_reserved_iova(struct iova_domain *from, struct iova_domain *to);
> @@ -87,5 +105,6 @@ struct iova *find_iova(struct iova_domain *iovad, unsigned
> long pfn);
> void put_iova_domain(struct iova_domain *iovad);
> struct iova *split_and_remove_iova(struct iova_domain *iovad,
> struct iova *iova, unsigned long pfn_lo, unsigned long pfn_hi);
> +void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad);
>
> #endif
> --
> 1.9.1
>
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