summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorRobin Murphy <robin.murphy@arm.com>2015-01-12 17:51:16 +0000
committerJoerg Roedel <jroedel@suse.de>2015-01-19 14:55:22 +0100
commit0fb5fe874c42942e16c450ae05da453e13a1c09e (patch)
tree3103ddfe5741c14f46acb7048c81fe2e7b1d0621
parent1b72250076dde4276acecf3a7da722b185703e78 (diff)
downloadop-kernel-dev-0fb5fe874c42942e16c450ae05da453e13a1c09e.zip
op-kernel-dev-0fb5fe874c42942e16c450ae05da453e13a1c09e.tar.gz
iommu: Make IOVA domain page size explicit
Systems may contain heterogeneous IOMMUs supporting differing minimum page sizes, which may also not be common with the CPU page size. Thus it is practical to have an explicit notion of IOVA granularity to simplify handling of mapping and allocation constraints. As an initial step, move the IOVA page granularity from an implicit compile-time constant to a per-domain property so we can make use of it in IOVA domain context at runtime. To keep the abstraction tidy, extend the little API of inline iova_* helpers to parallel some of the equivalent PAGE_* macros. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
-rw-r--r--drivers/iommu/intel-iommu.c9
-rw-r--r--drivers/iommu/iova.c12
-rw-r--r--include/linux/iova.h35
3 files changed, 49 insertions, 7 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 86f9e82..ae4c1a8 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1635,7 +1635,8 @@ static int dmar_init_reserved_ranges(void)
struct iova *iova;
int i;
- init_iova_domain(&reserved_iova_list, IOVA_START_PFN, DMA_32BIT_PFN);
+ init_iova_domain(&reserved_iova_list, VTD_PAGE_SIZE, IOVA_START_PFN,
+ DMA_32BIT_PFN);
lockdep_set_class(&reserved_iova_list.iova_rbtree_lock,
&reserved_rbtree_key);
@@ -1693,7 +1694,8 @@ static int domain_init(struct dmar_domain *domain, int guest_width)
int adjust_width, agaw;
unsigned long sagaw;
- init_iova_domain(&domain->iovad, IOVA_START_PFN, DMA_32BIT_PFN);
+ init_iova_domain(&domain->iovad, VTD_PAGE_SIZE, IOVA_START_PFN,
+ DMA_32BIT_PFN);
domain_reserve_special_ranges(domain);
/* calculate AGAW */
@@ -4316,7 +4318,8 @@ static int md_domain_init(struct dmar_domain *domain, int guest_width)
{
int adjust_width;
- init_iova_domain(&domain->iovad, IOVA_START_PFN, DMA_32BIT_PFN);
+ init_iova_domain(&domain->iovad, VTD_PAGE_SIZE, IOVA_START_PFN,
+ DMA_32BIT_PFN);
domain_reserve_special_ranges(domain);
/* calculate AGAW */
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index a3dbba8..9dd8208 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -55,12 +55,20 @@ void free_iova_mem(struct iova *iova)
}
void
-init_iova_domain(struct iova_domain *iovad, unsigned long start_pfn,
- unsigned long pfn_32bit)
+init_iova_domain(struct iova_domain *iovad, unsigned long granule,
+ unsigned long start_pfn, unsigned long pfn_32bit)
{
+ /*
+ * 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->cached32_node = NULL;
+ iovad->granule = granule;
iovad->start_pfn = start_pfn;
iovad->dma_32bit_pfn = pfn_32bit;
}
diff --git a/include/linux/iova.h b/include/linux/iova.h
index 591b196..3920a19 100644
--- a/include/linux/iova.h
+++ b/include/linux/iova.h
@@ -28,6 +28,7 @@ struct iova_domain {
spinlock_t iova_rbtree_lock; /* Lock to protect update of rbtree */
struct rb_root rbroot; /* iova domain rbtree root */
struct rb_node *cached32_node; /* Save last alloced node */
+ unsigned long granule; /* pfn granularity for this domain */
unsigned long start_pfn; /* Lower limit for this domain */
unsigned long dma_32bit_pfn;
};
@@ -37,6 +38,36 @@ static inline unsigned long iova_size(struct iova *iova)
return iova->pfn_hi - iova->pfn_lo + 1;
}
+static inline unsigned long iova_shift(struct iova_domain *iovad)
+{
+ return __ffs(iovad->granule);
+}
+
+static inline unsigned long iova_mask(struct iova_domain *iovad)
+{
+ return iovad->granule - 1;
+}
+
+static inline size_t iova_offset(struct iova_domain *iovad, dma_addr_t iova)
+{
+ return iova & iova_mask(iovad);
+}
+
+static inline size_t iova_align(struct iova_domain *iovad, size_t size)
+{
+ return ALIGN(size, iovad->granule);
+}
+
+static inline dma_addr_t iova_dma_addr(struct iova_domain *iovad, struct iova *iova)
+{
+ return (dma_addr_t)iova->pfn_lo << iova_shift(iovad);
+}
+
+static inline unsigned long iova_pfn(struct iova_domain *iovad, dma_addr_t iova)
+{
+ return iova >> iova_shift(iovad);
+}
+
int iommu_iova_cache_init(void);
void iommu_iova_cache_destroy(void);
@@ -50,8 +81,8 @@ struct iova *alloc_iova(struct iova_domain *iovad, unsigned long size,
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);
-void init_iova_domain(struct iova_domain *iovad, unsigned long start_pfn,
- unsigned long pfn_32bit);
+void init_iova_domain(struct iova_domain *iovad, unsigned long granule,
+ unsigned long start_pfn, unsigned long pfn_32bit);
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,
OpenPOWER on IntegriCloud