From: Leon Romanovsky <leonro@xxxxxxxxxx>
This patch adds a check if IOVA can be used for the page and size.
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
---
drivers/iommu/dma-iommu.c | 21 +++++++++++++++++++++
drivers/pci/p2pdma.c | 4 ++--
include/linux/dma-map-ops.h | 7 +++++++
include/linux/iommu-dma.h | 7 +++++++
4 files changed, 37 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 72763f76b712..3e2e382bb502 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -11,6 +11,7 @@
#include <linux/acpi_iort.h>
#include <linux/atomic.h>
#include <linux/crash_dump.h>
+#include <linux/cc_platform.h>
#include <linux/device.h>
#include <linux/dma-direct.h>
#include <linux/dma-map-ops.h>
@@ -1829,6 +1830,26 @@ void iommu_dma_unlink_range(struct device *dev, dma_addr_t start, size_t size,
iommu_iotlb_sync(domain, &iotlb_gather);
}
+bool iommu_can_use_iova(struct device *dev, struct page *page, size_t size,
+ enum dma_data_direction dir)
+{
+ enum pci_p2pdma_map_type map;
+
+ if (is_swiotlb_force_bounce(dev) || dev_use_swiotlb(dev, size, dir))
+ return false;
+
+ /* TODO: Rewrite this check to rely on specific struct page flags */
+ if (cc_platform_has(CC_ATTR_MEM_ENCRYPT))
+ return false;
+
+ if (page && is_pci_p2pdma_page(page)) {
+ map = pci_p2pdma_map_type(page->pgmap, dev);
+ return map == PCI_P2PDMA_MAP_THRU_HOST_BRIDGE;
+ }
+
+ return true;
+}
+
void iommu_setup_dma_ops(struct device *dev)
{
struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index 4f47a13cb500..6ceea32bb041 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -964,8 +964,8 @@ void pci_p2pmem_publish(struct pci_dev *pdev, bool publish)
}
EXPORT_SYMBOL_GPL(pci_p2pmem_publish);
-static enum pci_p2pdma_map_type pci_p2pdma_map_type(struct dev_pagemap *pgmap,
- struct device *dev)
+enum pci_p2pdma_map_type pci_p2pdma_map_type(struct dev_pagemap *pgmap,
+ struct device *dev)
{
enum pci_p2pdma_map_type type = PCI_P2PDMA_MAP_NOT_SUPPORTED;
struct pci_dev *provider = to_p2p_pgmap(pgmap)->provider;
diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h
index 103d9c66c445..936e822e9f40 100644
--- a/include/linux/dma-map-ops.h
+++ b/include/linux/dma-map-ops.h
@@ -516,6 +516,8 @@ struct pci_p2pdma_map_state {
enum pci_p2pdma_map_type
pci_p2pdma_map_segment(struct pci_p2pdma_map_state *state, struct device *dev,
struct scatterlist *sg);
+enum pci_p2pdma_map_type pci_p2pdma_map_type(struct dev_pagemap *pgmap,
+ struct device *dev);
#else /* CONFIG_PCI_P2PDMA */
static inline enum pci_p2pdma_map_type
pci_p2pdma_map_segment(struct pci_p2pdma_map_state *state, struct device *dev,
@@ -523,6 +525,11 @@ pci_p2pdma_map_segment(struct pci_p2pdma_map_state *state, struct device *dev,
{
return PCI_P2PDMA_MAP_NOT_SUPPORTED;
}
+static inline enum pci_p2pdma_map_type
+pci_p2pdma_map_type(struct dev_pagemap *pgmap, struct device *dev)
+{
+ return PCI_P2PDMA_MAP_NOT_SUPPORTED;
+}
#endif /* CONFIG_PCI_P2PDMA */
#endif /* _LINUX_DMA_MAP_OPS_H */
diff --git a/include/linux/iommu-dma.h b/include/linux/iommu-dma.h
index 21b0341f52b8..561d81b12d9c 100644
--- a/include/linux/iommu-dma.h
+++ b/include/linux/iommu-dma.h
@@ -66,6 +66,8 @@ dma_addr_t iommu_dma_link_range(struct dma_iova_state *state, phys_addr_t phys,
size_t size, unsigned long attrs);
void iommu_dma_unlink_range(struct device *dev, dma_addr_t start, size_t size,
enum dma_data_direction dir, unsigned long attrs);
+bool iommu_can_use_iova(struct device *dev, struct page *page, size_t size,
+ enum dma_data_direction dir);
#else
static inline bool use_dma_iommu(struct device *dev)
{
@@ -209,5 +211,10 @@ static inline void iommu_dma_unlink_range(struct device *dev, dma_addr_t start,
unsigned long attrs)
{
}
+static inline bool iommu_can_use_iova(struct device *dev, struct page *page,
+ size_t size, enum dma_data_direction dir)
+{
+ return false;
+}
#endif /* CONFIG_IOMMU_DMA */
#endif /* _LINUX_IOMMU_DMA_H */
--
2.46.0
