From: Will Davis
Implement 'map_resource' for the AMD IOMMU driver. Generalize the existing
map_page implementation to operate on a physical address, and make both
map_page and map_resource wrappers around that helper (and similiarly, for
unmap_page and unmap_resource).
This allows a device to map another's resource, to enable peer-to-peer
transactions.
Signed-off-by: Will Davis
Reviewed-by: Terence Ripperda
Reviewed-by: John Hubbard
---
drivers/iommu/amd_iommu.c | 76 +++
1 file changed, 63 insertions(+), 13 deletions(-)
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index e43d489..ca2dac6 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -503,6 +503,8 @@ DECLARE_STATS_COUNTER(cnt_map_single);
DECLARE_STATS_COUNTER(cnt_unmap_single);
DECLARE_STATS_COUNTER(cnt_map_sg);
DECLARE_STATS_COUNTER(cnt_unmap_sg);
+DECLARE_STATS_COUNTER(cnt_map_resource);
+DECLARE_STATS_COUNTER(cnt_unmap_resource);
DECLARE_STATS_COUNTER(cnt_alloc_coherent);
DECLARE_STATS_COUNTER(cnt_free_coherent);
DECLARE_STATS_COUNTER(cross_page);
@@ -541,6 +543,8 @@ static void amd_iommu_stats_init(void)
amd_iommu_stats_add(&cnt_unmap_single);
amd_iommu_stats_add(&cnt_map_sg);
amd_iommu_stats_add(&cnt_unmap_sg);
+ amd_iommu_stats_add(&cnt_map_resource);
+ amd_iommu_stats_add(&cnt_unmap_resource);
amd_iommu_stats_add(&cnt_alloc_coherent);
amd_iommu_stats_add(&cnt_free_coherent);
amd_iommu_stats_add(&cross_page);
@@ -2752,20 +2756,16 @@ static void __unmap_single(struct dma_ops_domain
*dma_dom,
}
/*
- * The exported map_single function for dma_ops.
+ * Wrapper function that contains code common to mapping a physical address
+ * range from a page or a resource.
*/
-static dma_addr_t map_page(struct device *dev, struct page *page,
- unsigned long offset, size_t size,
- enum dma_data_direction dir,
- struct dma_attrs *attrs)
+static dma_addr_t __map_phys(struct device *dev, phys_addr_t paddr,
+size_t size, enum dma_data_direction dir)
{
unsigned long flags;
struct protection_domain *domain;
dma_addr_t addr;
u64 dma_mask;
- phys_addr_t paddr = page_to_phys(page) + offset;
-
- INC_STATS_COUNTER(cnt_map_single);
domain = get_domain(dev);
if (PTR_ERR(domain) == -EINVAL)
@@ -2791,16 +2791,15 @@ out:
}
/*
- * The exported unmap_single function for dma_ops.
+ * Wrapper function that contains code common to unmapping a physical address
+ * range from a page or a resource.
*/
-static void unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size,
- enum dma_data_direction dir, struct dma_attrs *attrs)
+static void __unmap_phys(struct device *dev, dma_addr_t dma_addr, size_t size,
+enum dma_data_direction dir)
{
unsigned long flags;
struct protection_domain *domain;
- INC_STATS_COUNTER(cnt_unmap_single);
-
domain = get_domain(dev);
if (IS_ERR(domain))
return;
@@ -2815,6 +2814,55 @@ static void unmap_page(struct device *dev, dma_addr_t
dma_addr, size_t size,
}
/*
+ * The exported map_single function for dma_ops.
+ */
+static dma_addr_t map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size,
+ enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ INC_STATS_COUNTER(cnt_map_single);
+
+ return __map_phys(dev, page_to_phys(page) + offset, size, dir);
+}
+
+/*
+ * The exported unmap_single function for dma_ops.
+ */
+static void unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size,
+ enum dma_data_direction dir, struct dma_attrs *attrs)
+{
+ INC_STATS_COUNTER(cnt_unmap_single);
+
+ __unmap_phys(dev, dma_addr, size, dir);
+}
+
+/*
+ * The exported map_resource function for dma_ops.
+ */
+static dma_addr_t map_resource(struct device *dev, struct resource *res,
+ unsigned long offset, size_t size,
+ enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ INC_STATS_COUNTER(cnt_map_resource);
+
+ return __map_phys(dev, res->start + offset, size, dir);
+}
+
+/*
+ * The exported unmap_resource function for dma_ops.
+ */
+static void unmap_resource(struct device *dev, dma_addr_t dma_addr,
+ size_t size, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ INC_STATS_COUNTER(cnt_unmap_resource);
+
+ __unmap_phys(dev, dma_addr, size, dir);
+}
+
+/*
* The exported map_sg function for dma_ops (handles scatter-gather
* lists).
*/
@@ -3066,6 +3114,8 @@ static struct dma_map_ops amd_iommu_dma_op
