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authorLinus Torvalds <torvalds@linux-foundation.org>2016-05-27 13:49:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-05-27 13:49:24 -0700
commit2566278551d3db875bc3bbfc41b42f2e80392108 (patch)
treea8d9923a1b0f16e5af40fce0ee30e03f15956106
parente28e909c36bb5d6319953822d84df00fce7cbd18 (diff)
parent22e2f9fa63b092923873fc8a52955151f4d83274 (diff)
downloadlinux-2566278551d3db875bc3bbfc41b42f2e80392108.tar.gz
Merge git://git.infradead.org/intel-iommu
Pull intel IOMMU updates from David Woodhouse: "This patchset improves the scalability of the Intel IOMMU code by resolving two spinlock bottlenecks and eliminating the linearity of the IOVA allocator, yielding up to ~5x performance improvement and approaching 'iommu=off' performance" * git://git.infradead.org/intel-iommu: iommu/vt-d: Use per-cpu IOVA caching iommu/iova: introduce per-cpu caching to iova allocation iommu/vt-d: change intel-iommu to use IOVA frame numbers iommu/vt-d: avoid dev iotlb logic for domains with no dev iotlbs iommu/vt-d: only unmap mapped entries iommu/vt-d: correct flush_unmaps pfn usage iommu/vt-d: per-cpu deferred invalidation queues iommu/vt-d: refactoring of deferred flush entries
-rw-r--r--drivers/iommu/intel-iommu.c318
-rw-r--r--drivers/iommu/iova.c417
-rw-r--r--include/linux/iova.h23
3 files changed, 638 insertions, 120 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index b2bfb9594508..a644d0cec2d8 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -33,6 +33,7 @@
#include <linux/dma-mapping.h>
#include <linux/mempool.h>
#include <linux/memory.h>
+#include <linux/cpu.h>
#include <linux/timer.h>
#include <linux/io.h>
#include <linux/iova.h>
@@ -390,6 +391,7 @@ struct dmar_domain {
* domain ids are 16 bit wide according
* to VT-d spec, section 9.3 */
+ bool has_iotlb_device;
struct list_head devices; /* all devices' list */
struct iova_domain iovad; /* iova's that belong to this domain */
@@ -456,27 +458,32 @@ static LIST_HEAD(dmar_rmrr_units);
static void flush_unmaps_timeout(unsigned long data);
-static DEFINE_TIMER(unmap_timer, flush_unmaps_timeout, 0, 0);
+struct deferred_flush_entry {
+ unsigned long iova_pfn;
+ unsigned long nrpages;
+ struct dmar_domain *domain;
+ struct page *freelist;
+};
#define HIGH_WATER_MARK 250
-struct deferred_flush_tables {
+struct deferred_flush_table {
int next;
- struct iova *iova[HIGH_WATER_MARK];
- struct dmar_domain *domain[HIGH_WATER_MARK];
- struct page *freelist[HIGH_WATER_MARK];
+ struct deferred_flush_entry entries[HIGH_WATER_MARK];
+};
+
+struct deferred_flush_data {
+ spinlock_t lock;
+ int timer_on;
+ struct timer_list timer;
+ long size;
+ struct deferred_flush_table *tables;
};
-static struct deferred_flush_tables *deferred_flush;
+DEFINE_PER_CPU(struct deferred_flush_data, deferred_flush);
/* bitmap for indexing intel_iommus */
static int g_num_of_iommus;
-static DEFINE_SPINLOCK(async_umap_flush_lock);
-static LIST_HEAD(unmaps_to_do);
-
-static int timer_on;
-static long list_size;
-
static void domain_exit(struct dmar_domain *domain);
static void domain_remove_dev_info(struct dmar_domain *domain);
static void dmar_remove_one_dev_info(struct dmar_domain *domain,
@@ -1458,10 +1465,35 @@ iommu_support_dev_iotlb (struct dmar_domain *domain, struct intel_iommu *iommu,
return NULL;
}
+static void domain_update_iotlb(struct dmar_domain *domain)
+{
+ struct device_domain_info *info;
+ bool has_iotlb_device = false;
+
+ assert_spin_locked(&device_domain_lock);
+
+ list_for_each_entry(info, &domain->devices, link) {
+ struct pci_dev *pdev;
+
+ if (!info->dev || !dev_is_pci(info->dev))
+ continue;
+
+ pdev = to_pci_dev(info->dev);
+ if (pdev->ats_enabled) {
+ has_iotlb_device = true;
+ break;
+ }
+ }
+
+ domain->has_iotlb_device = has_iotlb_device;
+}
+
static void iommu_enable_dev_iotlb(struct device_domain_info *info)
{
struct pci_dev *pdev;
+ assert_spin_locked(&device_domain_lock);
+
if (!info || !dev_is_pci(info->dev))
return;
@@ -1481,6 +1513,7 @@ static void iommu_enable_dev_iotlb(struct device_domain_info *info)
#endif
if (info->ats_supported && !pci_enable_ats(pdev, VTD_PAGE_SHIFT)) {
info->ats_enabled = 1;
+ domain_update_iotlb(info->domain);
info->ats_qdep = pci_ats_queue_depth(pdev);
}
}
@@ -1489,6 +1522,8 @@ static void iommu_disable_dev_iotlb(struct device_domain_info *info)
{
struct pci_dev *pdev;
+ assert_spin_locked(&device_domain_lock);
+
if (!dev_is_pci(info->dev))
return;
@@ -1497,6 +1532,7 @@ static void iommu_disable_dev_iotlb(struct device_domain_info *info)
if (info->ats_enabled) {
pci_disable_ats(pdev);
info->ats_enabled = 0;
+ domain_update_iotlb(info->domain);
}
#ifdef CONFIG_INTEL_IOMMU_SVM
if (info->pri_enabled) {
@@ -1517,6 +1553,9 @@ static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
unsigned long flags;
struct device_domain_info *info;
+ if (!domain->has_iotlb_device)
+ return;
+
spin_lock_irqsave(&device_domain_lock, flags);
list_for_each_entry(info, &domain->devices, link) {
if (!info->ats_enabled)
@@ -1734,6 +1773,7 @@ static struct dmar_domain *alloc_domain(int flags)
memset(domain, 0, sizeof(*domain));
domain->nid = -1;
domain->flags = flags;
+ domain->has_iotlb_device = false;
INIT_LIST_HEAD(&domain->devices);
return domain;
@@ -1918,8 +1958,12 @@ static void domain_exit(struct dmar_domain *domain)
return;
/* Flush any lazy unmaps that may reference this domain */
- if (!intel_iommu_strict)
- flush_unmaps_timeout(0);
+ if (!intel_iommu_strict) {
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ flush_unmaps_timeout(cpu);
+ }
/* Remove associated devices and clear attached or cached domains */
rcu_read_lock();
@@ -3077,7 +3121,7 @@ static int __init init_dmars(void)
bool copied_tables = false;
struct device *dev;
struct intel_iommu *iommu;
- int i, ret;
+ int i, ret, cpu;
/*
* for each drhd
@@ -3110,11 +3154,20 @@ static int __init init_dmars(void)
goto error;
}
- deferred_flush = kzalloc(g_num_of_iommus *
- sizeof(struct deferred_flush_tables), GFP_KERNEL);
- if (!deferred_flush) {
- ret = -ENOMEM;
- goto free_g_iommus;
+ for_each_possible_cpu(cpu) {
+ struct deferred_flush_data *dfd = per_cpu_ptr(&deferred_flush,
+ cpu);
+
+ dfd->tables = kzalloc(g_num_of_iommus *
+ sizeof(struct deferred_flush_table),
+ GFP_KERNEL);
+ if (!dfd->tables) {
+ ret = -ENOMEM;
+ goto free_g_iommus;
+ }
+
+ spin_lock_init(&dfd->lock);
+ setup_timer(&dfd->timer, flush_unmaps_timeout, cpu);
}
for_each_active_iommu(iommu, drhd) {
@@ -3291,19 +3344,20 @@ free_iommu:
disable_dmar_iommu(iommu);
free_dmar_iommu(iommu);
}
- kfree(deferred_flush);
free_g_iommus:
+ for_each_possible_cpu(cpu)
+ kfree(per_cpu_ptr(&deferred_flush, cpu)->tables);
kfree(g_iommus);
error:
return ret;
}
/* This takes a number of _MM_ pages, not VTD pages */
-static struct iova *intel_alloc_iova(struct device *dev,
+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);
@@ -3316,19 +3370,19 @@ static struct iova *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;
+ 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 NULL;
+ return 0;
}
- return iova;
+ return iova_pfn;
}
static struct dmar_domain *__get_valid_domain_for_dev(struct device *dev)
@@ -3426,7 +3480,7 @@ static dma_addr_t __intel_map_single(struct device *dev, phys_addr_t paddr,
{
struct dmar_domain *domain;
phys_addr_t start_paddr;
- struct iova *iova;
+ unsigned long iova_pfn;
int prot = 0;
int ret;
struct intel_iommu *iommu;
@@ -3444,8 +3498,8 @@ static dma_addr_t __intel_map_single(struct device *dev, phys_addr_t paddr,
iommu = domain_get_iommu(domain);
size = aligned_nrpages(paddr, size);
- iova = intel_alloc_iova(dev, domain, dma_to_mm_pfn(size), dma_mask);
- if (!iova)
+ iova_pfn = intel_alloc_iova(dev, domain, dma_to_mm_pfn(size), dma_mask);
+ if (!iova_pfn)
goto error;
/*
@@ -3463,7 +3517,7 @@ static dma_addr_t __intel_map_single(struct device *dev, phys_addr_t paddr,
* might have two guest_addr mapping to the same host paddr, but this
* is not a big problem
*/
- ret = domain_pfn_mapping(domain, mm_to_dma_pfn(iova->pfn_lo),
+ ret = domain_pfn_mapping(domain, mm_to_dma_pfn(iova_pfn),
mm_to_dma_pfn(paddr_pfn), size, prot);
if (ret)
goto error;
@@ -3471,18 +3525,18 @@ static dma_addr_t __intel_map_single(struct device *dev, phys_addr_t paddr,
/* it's a non-present to present mapping. Only flush if caching mode */
if (cap_caching_mode(iommu->cap))
iommu_flush_iotlb_psi(iommu, domain,
- mm_to_dma_pfn(iova->pfn_lo),
+ mm_to_dma_pfn(iova_pfn),
size, 0, 1);
else
iommu_flush_write_buffer(iommu);
- start_paddr = (phys_addr_t)iova->pfn_lo << PAGE_SHIFT;
+ start_paddr = (phys_addr_t)iova_pfn << PAGE_SHIFT;
start_paddr += paddr & ~PAGE_MASK;
return start_paddr;
error:
- if (iova)
- __free_iova(&domain->iovad, iova);
+ if (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;
@@ -3497,91 +3551,120 @@ static dma_addr_t intel_map_page(struct device *dev, struct page *page,
dir, *dev->dma_mask);
}
-static void flush_unmaps(void)
+static void flush_unmaps(struct deferred_flush_data *flush_data)
{
int i, j;
- timer_on = 0;
+ flush_data->timer_on = 0;
/* just flush them all */
for (i = 0; i < g_num_of_iommus; i++) {
struct intel_iommu *iommu = g_iommus[i];
+ struct deferred_flush_table *flush_table =
+ &flush_data->tables[i];
if (!iommu)
continue;
- if (!deferred_flush[i].next)
+ if (!flush_table->next)
continue;
/* In caching mode, global flushes turn emulation expensive */
if (!cap_caching_mode(iommu->cap))
iommu->flush.flush_iotlb(iommu, 0, 0, 0,
DMA_TLB_GLOBAL_FLUSH);
- for (j = 0; j < deferred_flush[i].next; j++) {
+ for (j = 0; j < flush_table->next; j++) {
unsigned long mask;
- struct iova *iova = deferred_flush[i].iova[j];
- struct dmar_domain *domain = deferred_flush[i].domain[j];
+ struct deferred_flush_entry *entry =
+ &flush_table->entries[j];
+ unsigned long iova_pfn = entry->iova_pfn;
+ unsigned long nrpages = entry->nrpages;
+ struct dmar_domain *domain = entry->domain;
+ struct page *freelist = entry->freelist;
/* On real hardware multiple invalidations are expensive */
if (cap_caching_mode(iommu->cap))
iommu_flush_iotlb_psi(iommu, domain,
- iova->pfn_lo, iova_size(iova),
- !deferred_flush[i].freelist[j], 0);
+ mm_to_dma_pfn(iova_pfn),
+ nrpages, !freelist, 0);
else {
- mask = ilog2(mm_to_dma_pfn(iova_size(iova)));
- iommu_flush_dev_iotlb(deferred_flush[i].domain[j],
- (uint64_t)iova->pfn_lo << PAGE_SHIFT, mask);
+ mask = ilog2(nrpages);
+ iommu_flush_dev_iotlb(domain,
+ (uint64_t)iova_pfn << PAGE_SHIFT, mask);
}
- __free_iova(&deferred_flush[i].domain[j]->iovad, iova);
- if (deferred_flush[i].freelist[j])
- dma_free_pagelist(deferred_flush[i].freelist[j]);
+ free_iova_fast(&domain->iovad, iova_pfn, nrpages);
+ if (freelist)
+ dma_free_pagelist(freelist);
}
- deferred_flush[i].next = 0;
+ flush_table->next = 0;
}
- list_size = 0;
+ flush_data->size = 0;
}
-static void flush_unmaps_timeout(unsigned long data)
+static void flush_unmaps_timeout(unsigned long cpuid)
{
+ struct deferred_flush_data *flush_data = per_cpu_ptr(&deferred_flush, cpuid);
unsigned long flags;
- spin_lock_irqsave(&async_umap_flush_lock, flags);
- flush_unmaps();
- spin_unlock_irqrestore(&async_umap_flush_lock, flags);
+ spin_lock_irqsave(&flush_data->lock, flags);
+ flush_unmaps(flush_data);
+ spin_unlock_irqrestore(&flush_data->lock, flags);
}
-static void add_unmap(struct dmar_domain *dom, struct iova *iova, struct page *freelist)
+static void add_unmap(struct dmar_domain *dom, unsigned long iova_pfn,
+ unsigned long nrpages, struct page *freelist)
{
unsigned long flags;
- int next, iommu_id;
+ int entry_id, iommu_id;
struct intel_iommu *iommu;
+ struct deferred_flush_entry *entry;
+ struct deferred_flush_data *flush_data;
+ unsigned int cpuid;
- spin_lock_irqsave(&async_umap_flush_lock, flags);
- if (list_size == HIGH_WATER_MARK)
- flush_unmaps();
+ cpuid = get_cpu();
+ flush_data = per_cpu_ptr(&deferred_flush, cpuid);
+
+ /* Flush all CPUs' entries to avoid deferring too much. If
+ * this becomes a bottleneck, can just flush us, and rely on
+ * flush timer for the rest.
+ */
+ if (flush_data->size == HIGH_WATER_MARK) {
+ int cpu;
+
+ for_each_online_cpu(cpu)
+ flush_unmaps_timeout(cpu);
+ }
+
+ spin_lock_irqsave(&flush_data->lock, flags);
iommu = domain_get_iommu(dom);
iommu_id = iommu->seq_id;
- next = deferred_flush[iommu_id].next;
- deferred_flush[iommu_id].domain[next] = dom;
- deferred_flush[iommu_id].iova[next] = iova;
- deferred_flush[iommu_id].freelist[next] = freelist;
- deferred_flush[iommu_id].next++;
+ entry_id = flush_data->tables[iommu_id].next;
+ ++(flush_data->tables[iommu_id].next);
- if (!timer_on) {
- mod_timer(&unmap_timer, jiffies + msecs_to_jiffies(10));
- timer_on = 1;
+ entry = &flush_data->tables[iommu_id].entries[entry_id];
+ entry->domain = dom;
+ entry->iova_pfn = iova_pfn;
+ entry->nrpages = nrpages;
+ entry->freelist = freelist;
+
+ if (!flush_data->timer_on) {
+ mod_timer(&flush_data->timer, jiffies + msecs_to_jiffies(10));
+ flush_data->timer_on = 1;
}
- list_size++;
- spin_unlock_irqrestore(&async_umap_flush_lock, flags);
+ flush_data->size++;
+ spin_unlock_irqrestore(&flush_data->lock, flags);
+
+ put_cpu();
}
-static void intel_unmap(struct device *dev, dma_addr_t dev_addr)
+static void intel_unmap(struct device *dev, dma_addr_t dev_addr, size_t size)
{
struct dmar_domain *domain;
unsigned long start_pfn, last_pfn;
- struct iova *iova;
+ unsigned long nrpages;
+ unsigned long iova_pfn;
struct intel_iommu *iommu;
struct page *freelist;
@@ -3593,13 +3676,11 @@ static void intel_unmap(struct device *dev, dma_addr_t dev_addr)
iommu = domain_get_iommu(domain);
- iova = find_iova(&domain->iovad, IOVA_PFN(dev_addr));
- if (WARN_ONCE(!iova, "Driver unmaps unmatched page at PFN %llx\n",
- (unsigned long long)dev_addr))
- return;
+ iova_pfn = IOVA_PFN(dev_addr);
- start_pfn = mm_to_dma_pfn(iova->pfn_lo);
- last_pfn = mm_to_dma_pfn(iova->pfn_hi + 1) - 1;
+ nrpages = aligned_nrpages(dev_addr, size);
+ start_pfn = mm_to_dma_pfn(iova_pfn);
+ last_pfn = start_pfn + nrpages - 1;
pr_debug("Device %s unmapping: pfn %lx-%lx\n",
dev_name(dev), start_pfn, last_pfn);
@@ -3608,12 +3689,12 @@ static void intel_unmap(struct device *dev, dma_addr_t dev_addr)
if (intel_iommu_strict) {
iommu_flush_iotlb_psi(iommu, domain, start_pfn,
- last_pfn - start_pfn + 1, !freelist, 0);
+ nrpages, !freelist, 0);
/* free iova */
- __free_iova(&domain->iovad, iova);
+ free_iova_fast(&domain->iovad, iova_pfn, dma_to_mm_pfn(nrpages));
dma_free_pagelist(freelist);
} else {
- add_unmap(domain, iova, freelist);
+ add_unmap(domain, iova_pfn, nrpages, freelist);
/*
* queue up the release of the unmap to save the 1/6th of the
* cpu used up by the iotlb flush operation...
@@ -3625,7 +3706,7 @@ static void intel_unmap_page(struct device *dev, dma_addr_t dev_addr,
size_t size, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
- intel_unmap(dev, dev_addr);
+ intel_unmap(dev, dev_addr, size);
}
static void *intel_alloc_coherent(struct device *dev, size_t size,
@@ -3684,7 +3765,7 @@ static void intel_free_coherent(struct device *dev, size_t size, void *vaddr,
size = PAGE_ALIGN(size);
order = get_order(size);
- intel_unmap(dev, dma_handle);
+ intel_unmap(dev, dma_handle, size);
if (!dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT))
__free_pages(page, order);
}
@@ -3693,7 +3774,16 @@ static void intel_unmap_sg(struct device *dev, struct scatterlist *sglist,
int nelems, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
- intel_unmap(dev, sglist[0].dma_address);
+ dma_addr_t startaddr = sg_dma_address(sglist) & PAGE_MASK;
+ unsigned long nrpages = 0;
+ struct scatterlist *sg;
+ int i;
+
+ for_each_sg(sglist, sg, nelems, i) {
+ nrpages += aligned_nrpages(sg_dma_address(sg), sg_dma_len(sg));
+ }
+
+ intel_unmap(dev, startaddr, nrpages << VTD_PAGE_SHIFT);
}
static int intel_nontranslate_map_sg(struct device *hddev,
@@ -3717,7 +3807,7 @@ static int intel_map_sg(struct device *dev, struct scatterlist *sglist, int nele
struct dmar_domain *domain;
size_t size = 0;
int prot = 0;
- struct iova *iova = NULL;
+ unsigned long iova_pfn;
int ret;
struct scatterlist *sg;
unsigned long start_vpfn;
@@ -3736,9 +3826,9 @@ static int intel_map_sg(struct device *dev, struct scatterlist *sglist, int nele
for_each_sg(sglist, sg, nelems, i)
size += aligned_nrpages(sg->offset, sg->length);
- iova = intel_alloc_iova(dev, domain, dma_to_mm_pfn(size),
+ iova_pfn = intel_alloc_iova(dev, domain, dma_to_mm_pfn(size),
*dev->dma_mask);
- if (!iova) {
+ if (!iova_pfn) {
sglist->dma_length = 0;
return 0;
}
@@ -3753,13 +3843,13 @@ static int intel_map_sg(struct device *dev, struct scatterlist *sglist, int nele
if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)
prot |= DMA_PTE_WRITE;
- start_vpfn = mm_to_dma_pfn(iova->pfn_lo);
+ start_vpfn = mm_to_dma_pfn(iova_pfn);
ret = domain_sg_mapping(domain, start_vpfn, sglist, size, prot);
if (unlikely(ret)) {
dma_pte_free_pagetable(domain, start_vpfn,
start_vpfn + size - 1);
- __free_iova(&domain->iovad, iova);
+ free_iova_fast(&domain->iovad, iova_pfn, dma_to_mm_pfn(size));
return 0;
}
@@ -4498,6 +4588,46 @@ 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)
+{
+ unsigned int cpu = (unsigned long)v;
+
+ switch (action) {
+ case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
+ free_all_cpu_cached_iovas(cpu);
+ flush_unmaps_timeout(cpu);
+ break;
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block intel_iommu_cpu_nb = {
+ .notifier_call = intel_iommu_cpu_notifier,
+};
static ssize_t intel_iommu_show_version(struct device *dev,
struct device_attribute *attr,
@@ -4631,7 +4761,6 @@ int __init intel_iommu_init(void)
up_write(&dmar_global_lock);
pr_info("Intel(R) Virtualization Technology for Directed I/O\n");
- init_timer(&unmap_timer);
#ifdef CONFIG_SWIOTLB
swiotlb = 0;
#endif
@@ -4648,6 +4777,7 @@ int __init intel_iommu_init(void)
bus_register_notifier(&pci_bus_type, &device_nb);
if (si_domain && !hw_pass_through)
register_memory_notifier(&intel_iommu_memory_nb);
+ register_hotcpu_notifier(&intel_iommu_cpu_nb);
intel_iommu_enabled = 1;
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index fa0adef32bd6..ba764a0835d3 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -20,6 +20,17 @@
#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,
+ unsigned long pfn,
+ unsigned long size);
+static unsigned long iova_rcache_get(struct iova_domain *iovad,
+ unsigned long size,
+ unsigned long limit_pfn);
+static void init_iova_rcaches(struct iova_domain *iovad);
+static void free_iova_rcaches(struct iova_domain *iovad);
void
init_iova_domain(struct iova_domain *iovad, unsigned long granule,
@@ -38,6 +49,7 @@ 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 +303,18 @@ 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 +324,35 @@ 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 +367,8 @@ __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 +391,63 @@ 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)
+{
+ bool flushed_rcache = false;
+ unsigned long iova_pfn;
+ struct iova *new_iova;
+
+ iova_pfn = iova_rcache_get(iovad, size, limit_pfn);
+ if (iova_pfn)
+ return iova_pfn;
+
+retry:
+ new_iova = alloc_iova(iovad, size, limit_pfn, true);
+ if (!new_iova) {
+ unsigned int cpu;
+
+ if (flushed_rcache)
+ return 0;
+
+ /* Try replenishing IOVAs by flushing rcache. */
+ flushed_rcache = true;
+ for_each_online_cpu(cpu)
+ free_cpu_cached_iovas(cpu, iovad);
+ goto retry;
+ }
+
+ return new_iova->pfn_lo;
+}
+EXPORT_SYMBOL_GPL(alloc_iova_fast);
+
+/**
+ * free_iova_fast - free iova pfn range into rcache
+ * @iovad: - iova domain in question.
+ * @pfn: - pfn that is allocated previously
+ * @size: - # of pages in range
+ * This functions frees an iova range by trying to put it into the rcache,
+ * falling back to regular iova deallocation via free_iova() if this fails.
+ */
+void
+free_iova_fast(struct iova_domain *iovad, unsigned long pfn, unsigned long size)
+{
+ if (iova_rcache_insert(iovad, pfn, size))
+ return;
+
+ free_iova(iovad, pfn);
+}
+EXPORT_SYMBOL_GPL(free_iova_fast);
+
+/**
* put_iova_domain - destroys the iova doamin
* @iovad: - iova domain in question.
* All the iova's in that domain are destroyed.
@@ -379,6 +457,7 @@ 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 +629,295 @@ 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 {
+ spinlock_t lock;
+ struct iova_magazine *loaded;
+ struct iova_magazine *prev;
+};
+
+static struct iova_magazine *iova_magazine_alloc(gfp_t flags)
+{
+ return kzalloc(sizeof(struct iova_magazine), flags);
+}
+
+static void iova_magazine_free(struct iova_magazine *mag)
+{
+ kfree(mag);
+}
+
+static void
+iova_magazine_free_pfns(struct iova_magazine *mag, struct iova_domain *iovad)
+{
+ unsigned long flags;
+ int i;
+
+ if (!mag)
+ return;
+
+ spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
+
+ for (i = 0 ; i < mag->size; ++i) {
+ struct iova *iova = private_find_iova(iovad, mag->pfns[i]);
+
+ BUG_ON(!iova);
+ private_free_iova(iovad, iova);
+ }
+
+ spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+
+ mag->size = 0;
+}
+
+static bool iova_magazine_full(struct iova_magazine *mag)
+{
+ return (mag && mag->size == IOVA_MAG_SIZE);
+}
+
+static bool iova_magazine_empty(struct iova_magazine *mag)
+{
+ return (!mag || mag->size == 0);
+}
+
+static unsigned long iova_magazine_pop(struct iova_magazine *mag,
+ unsigned long limit_pfn)
+{
+ BUG_ON(iova_magazine_empty(mag));
+
+ if (mag->pfns[mag->size - 1] >= limit_pfn)
+ return 0;
+
+ 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);
+ spin_lock_init(&cpu_rcache->lock);
+ cpu_rcache->loaded = iova_magazine_alloc(GFP_KERNEL);
+ cpu_rcache->prev = iova_magazine_alloc(GFP_KERNEL);
+ }
+ }
+}
+
+/*
+ * Try inserting IOVA range starting with 'iova_pfn' into 'rcache', and
+ * return true on success. Can fail if rcache is full and we can't free
+ * space, and free_iova() (our only caller) will then return the IOVA
+ * range to the rbtree instead.
+ */
+static bool __iova_rcache_insert(struct iova_domain *iovad,
+ struct iova_rcache *rcache,
+ unsigned long iova_pfn)
+{
+ struct iova_magazine *mag_to_free = NULL;
+ struct iova_cpu_rcache *cpu_rcache;
+ bool can_insert = false;
+ unsigned long flags;
+
+ cpu_rcache = this_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 = this_cpu_ptr(rcache->cpu_rcaches);
+ spin_lock_irqsave(&cpu_rcache->lock, flags);
+
+ if (!iova_magazine_empty(cpu_rcache->loaded)) {
+ has_pfn = true;
+ } else if (!iova_magazine_empty(cpu_rcache->prev)) {
+ swap(cpu_rcache->prev, cpu_rcache->loaded);
+ has_pfn = true;
+ } else {
+ spin_lock(&rcache->lock);
+ if (rcache->depot_size > 0) {
+ iova_magazine_free(cpu_rcache->loaded);
+ cpu_rcache->loaded = rcache->depot[--rcache->depot_size];
+ has_pfn = true;
+ }
+ spin_unlock(&rcache->lock);
+ }
+
+ if (has_pfn)
+ iova_pfn = iova_magazine_pop(cpu_rcache->loaded, limit_pfn);
+
+ spin_unlock_irqrestore(&cpu_rcache->lock, flags);
+
+ return iova_pfn;
+}
+
+/*
+ * Try to satisfy IOVA allocation range from rcache. Fail if requested
+ * size is too big or the DMA limit we are given isn't satisfied by the
+ * top element in the magazine.
+ */
+static unsigned long iova_rcache_get(struct iova_domain *iovad,
+ unsigned long size,
+ unsigned long limit_pfn)
+{
+ unsigned int log_size = order_base_2(size);
+
+ if (log_size >= IOVA_RANGE_CACHE_MAX_SIZE)
+ return 0;
+
+ return __iova_rcache_get(&iovad->rcaches[log_size], limit_pfn);
+}
+
+/*
+ * Free a cpu's 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);
+ unsigned long flags;
+
+ spin_lock_irqsave(&cpu_rcache->lock, flags);
+
+ 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);
+
+ spin_unlock_irqrestore(&cpu_rcache->lock, flags);
+}
+
+/*
+ * free rcache data structures.
+ */
+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;
+ unsigned long flags;
+ int i;
+
+ for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
+ rcache = &iovad->rcaches[i];
+ cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
+ spin_lock_irqsave(&cpu_rcache->lock, flags);
+ iova_magazine_free_pfns(cpu_rcache->loaded, iovad);
+ iova_magazine_free_pfns(cpu_rcache->prev, iovad);
+ spin_unlock_irqrestore(&cpu_rcache->lock, flags);
+ }
+}
+
MODULE_AUTHOR("Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>");
MODULE_LICENSE("GPL");
diff --git a/include/linux/iova.h b/include/linux/iova.h
index 92f7177db2ce..f27bb2c62fca 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;
+ unsigned long 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