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authorJoerg Roedel <jroedel@suse.de>2017-08-23 16:50:04 +0300
committerJoerg Roedel <jroedel@suse.de>2017-08-30 19:07:13 +0300
commitadd02cfdc9bc2987b0121861d5bb0c7392865be9 (patch)
treecb6fac974f4197968af1346bc13d6fce9f461cf7 /include/linux/iommu.h
parent0688a09990986cd8c2fda26afb04ce0a599ced3f (diff)
downloadlinux-add02cfdc9bc2987b0121861d5bb0c7392865be9.tar.xz
iommu: Introduce Interface for IOMMU TLB Flushing
With the current IOMMU-API the hardware TLBs have to be flushed in every iommu_ops->unmap() call-back. For unmapping large amounts of address space, like it happens when a KVM domain with assigned devices is destroyed, this causes thousands of unnecessary TLB flushes in the IOMMU hardware because the unmap call-back runs for every unmapped physical page. With the TLB Flush Interface and the new iommu_unmap_fast() function introduced here the need to clean the hardware TLBs is removed from the unmapping code-path. Users of iommu_unmap_fast() have to explicitly call the TLB-Flush functions to sync the page-table changes to the hardware. Three functions for TLB-Flushes are introduced: * iommu_flush_tlb_all() - Flushes all TLB entries associated with that domain. TLBs entries are flushed when this function returns. * iommu_tlb_range_add() - This will add a given range to the flush queue for this domain. * iommu_tlb_sync() - Flushes all queued ranges from the hardware TLBs. Returns when the flush is finished. The semantic of this interface is intentionally similar to the iommu_gather_ops from the io-pgtable code. Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'include/linux/iommu.h')
-rw-r--r--include/linux/iommu.h50
1 files changed, 49 insertions, 1 deletions
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index f1ce8e517d8d..50be4fd338e4 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -167,6 +167,10 @@ struct iommu_resv_region {
* @map: map a physically contiguous memory region to an iommu domain
* @unmap: unmap a physically contiguous memory region from an iommu domain
* @map_sg: map a scatter-gather list of physically contiguous memory chunks
+ * @flush_tlb_all: Synchronously flush all hardware TLBs for this domain
+ * @tlb_range_add: Add a given iova range to the flush queue for this domain
+ * @tlb_sync: Flush all queued ranges from the hardware TLBs and empty flush
+ * queue
* to an iommu domain
* @iova_to_phys: translate iova to physical address
* @add_device: add device to iommu grouping
@@ -199,6 +203,10 @@ struct iommu_ops {
size_t size);
size_t (*map_sg)(struct iommu_domain *domain, unsigned long iova,
struct scatterlist *sg, unsigned int nents, int prot);
+ void (*flush_iotlb_all)(struct iommu_domain *domain);
+ void (*iotlb_range_add)(struct iommu_domain *domain,
+ unsigned long iova, size_t size);
+ void (*iotlb_sync)(struct iommu_domain *domain);
phys_addr_t (*iova_to_phys)(struct iommu_domain *domain, dma_addr_t iova);
int (*add_device)(struct device *dev);
void (*remove_device)(struct device *dev);
@@ -286,7 +294,9 @@ extern struct iommu_domain *iommu_get_domain_for_dev(struct device *dev);
extern int iommu_map(struct iommu_domain *domain, unsigned long iova,
phys_addr_t paddr, size_t size, int prot);
extern size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova,
- size_t size);
+ size_t size);
+extern size_t iommu_unmap_fast(struct iommu_domain *domain,
+ unsigned long iova, size_t size);
extern size_t default_iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
struct scatterlist *sg,unsigned int nents,
int prot);
@@ -343,6 +353,25 @@ extern void iommu_domain_window_disable(struct iommu_domain *domain, u32 wnd_nr)
extern int report_iommu_fault(struct iommu_domain *domain, struct device *dev,
unsigned long iova, int flags);
+static inline void iommu_flush_tlb_all(struct iommu_domain *domain)
+{
+ if (domain->ops->flush_iotlb_all)
+ domain->ops->flush_iotlb_all(domain);
+}
+
+static inline void iommu_tlb_range_add(struct iommu_domain *domain,
+ unsigned long iova, size_t size)
+{
+ if (domain->ops->iotlb_range_add)
+ domain->ops->iotlb_range_add(domain, iova, size);
+}
+
+static inline void iommu_tlb_sync(struct iommu_domain *domain)
+{
+ if (domain->ops->iotlb_sync)
+ domain->ops->iotlb_sync(domain);
+}
+
static inline size_t iommu_map_sg(struct iommu_domain *domain,
unsigned long iova, struct scatterlist *sg,
unsigned int nents, int prot)
@@ -436,6 +465,12 @@ static inline int iommu_unmap(struct iommu_domain *domain, unsigned long iova,
return -ENODEV;
}
+static inline int iommu_unmap_fast(struct iommu_domain *domain, unsigned long iova,
+ int gfp_order)
+{
+ return -ENODEV;
+}
+
static inline size_t iommu_map_sg(struct iommu_domain *domain,
unsigned long iova, struct scatterlist *sg,
unsigned int nents, int prot)
@@ -443,6 +478,19 @@ static inline size_t iommu_map_sg(struct iommu_domain *domain,
return -ENODEV;
}
+static inline void iommu_flush_tlb_all(struct iommu_domain *domain)
+{
+}
+
+static inline void iommu_tlb_range_add(struct iommu_domain *domain,
+ unsigned long iova, size_t size)
+{
+}
+
+static inline void iommu_tlb_sync(struct iommu_domain *domain)
+{
+}
+
static inline int iommu_domain_window_enable(struct iommu_domain *domain,
u32 wnd_nr, phys_addr_t paddr,
u64 size, int prot)