iommu/vt-d: change intel-iommu to use IOVA frame numbers
Make intel-iommu map/unmap/invalidate work with IOVA pfns instead of
pointers to "struct iova". This avoids using the iova struct from the IOVA
red-black tree and the resulting explicit find_iova() on unmap.
This patch will allow us to cache IOVAs in the next patch, in order to
avoid rbtree operations for the majority of map/unmap operations.
Note: In eliminating the find_iova() operation, we have also eliminated
the sanity check previously done in the unmap flow. Arguably, this was
overhead that is better avoided in production code, but it could be
brought back as a debug option for driver development.
Signed-off-by: Omer Peleg <omer@cs.technion.ac.il>
[mad@cs.technion.ac.il: rebased, fixed to not break iova api, and reworded
the commit message]
Signed-off-by: Adam Morrison <mad@cs.technion.ac.il>
Reviewed-by: Shaohua Li <shli@fb.com>
Reviewed-by: Ben Serebrin <serebrin@google.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index d100583..a8babc4 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -459,7 +459,7 @@
static void flush_unmaps_timeout(unsigned long data);
struct deferred_flush_entry {
- struct iova *iova;
+ unsigned long iova_pfn;
unsigned long nrpages;
struct dmar_domain *domain;
struct page *freelist;
@@ -3353,7 +3353,7 @@
}
/* 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)
{
@@ -3373,16 +3373,16 @@
iova = alloc_iova(&domain->iovad, nrpages,
IOVA_PFN(DMA_BIT_MASK(32)), 1);
if (iova)
- return iova;
+ return iova->pfn_lo;
}
iova = alloc_iova(&domain->iovad, nrpages, IOVA_PFN(dma_mask), 1);
if (unlikely(!iova)) {
pr_err("Allocating %ld-page iova for %s failed",
nrpages, dev_name(dev));
- return NULL;
+ return 0;
}
- return iova;
+ return iova->pfn_lo;
}
static struct dmar_domain *__get_valid_domain_for_dev(struct device *dev)
@@ -3480,7 +3480,7 @@
{
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;
@@ -3498,8 +3498,8 @@
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;
/*
@@ -3517,7 +3517,7 @@
* 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;
@@ -3525,18 +3525,18 @@
/* 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(&domain->iovad, iova_pfn);
pr_err("Device %s request: %zx@%llx dir %d --- failed\n",
dev_name(dev), size, (unsigned long long)paddr, dir);
return 0;
@@ -3576,7 +3576,7 @@
unsigned long mask;
struct deferred_flush_entry *entry =
&flush_table->entries[j];
- struct iova *iova = entry->iova;
+ unsigned long iova_pfn = entry->iova_pfn;
unsigned long nrpages = entry->nrpages;
struct dmar_domain *domain = entry->domain;
struct page *freelist = entry->freelist;
@@ -3584,14 +3584,14 @@
/* On real hardware multiple invalidations are expensive */
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),
nrpages, !freelist, 0);
else {
mask = ilog2(nrpages);
iommu_flush_dev_iotlb(domain,
- (uint64_t)iova->pfn_lo << PAGE_SHIFT, mask);
+ (uint64_t)iova_pfn << PAGE_SHIFT, mask);
}
- __free_iova(&domain->iovad, iova);
+ free_iova(&domain->iovad, iova_pfn);
if (freelist)
dma_free_pagelist(freelist);
}
@@ -3611,7 +3611,7 @@
spin_unlock_irqrestore(&flush_data->lock, flags);
}
-static void add_unmap(struct dmar_domain *dom, struct iova *iova,
+static void add_unmap(struct dmar_domain *dom, unsigned long iova_pfn,
unsigned long nrpages, struct page *freelist)
{
unsigned long flags;
@@ -3645,7 +3645,7 @@
entry = &flush_data->tables[iommu_id].entries[entry_id];
entry->domain = dom;
- entry->iova = iova;
+ entry->iova_pfn = iova_pfn;
entry->nrpages = nrpages;
entry->freelist = freelist;
@@ -3664,7 +3664,7 @@
struct dmar_domain *domain;
unsigned long start_pfn, last_pfn;
unsigned long nrpages;
- struct iova *iova;
+ unsigned long iova_pfn;
struct intel_iommu *iommu;
struct page *freelist;
@@ -3676,13 +3676,10 @@
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);
nrpages = aligned_nrpages(dev_addr, size);
- start_pfn = mm_to_dma_pfn(iova->pfn_lo);
+ start_pfn = mm_to_dma_pfn(iova_pfn);
last_pfn = start_pfn + nrpages - 1;
pr_debug("Device %s unmapping: pfn %lx-%lx\n",
@@ -3694,10 +3691,10 @@
iommu_flush_iotlb_psi(iommu, domain, start_pfn,
nrpages, !freelist, 0);
/* free iova */
- __free_iova(&domain->iovad, iova);
+ free_iova(&domain->iovad, iova_pfn);
dma_free_pagelist(freelist);
} else {
- add_unmap(domain, iova, nrpages, 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...
@@ -3810,7 +3807,7 @@
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;
@@ -3829,9 +3826,9 @@
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;
}
@@ -3846,13 +3843,13 @@
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(&domain->iovad, iova_pfn);
return 0;
}