Hi,
On 1/28/21 4:01 AM, Chuck Lever wrote:
From: Isaac J. Manjarres <[email protected]>
Add support for IOMMU drivers to have their own map_sg() callbacks.
This completes the path for having iommu_map_sg() invoke an IOMMU
driver's map_sg() callback, which can then invoke the io-pgtable
map_sg() callback with the entire scatter-gather list, so that it
can be processed entirely in the io-pgtable layer.
For IOMMU drivers that do not provide a callback, the default
implementation of iterating through the scatter-gather list, while
calling iommu_map() will be used.
Signed-off-by: Isaac J. Manjarres <[email protected]>
Tested-by: Sai Prakash Ranjan <[email protected]>
[ cel: adjusted new iotlb_sync_map call site ]
Signed-off-by: Chuck Lever <[email protected]>
---
drivers/iommu/iommu.c | 12 ++++++++++++
include/linux/iommu.h | 5 +++++
2 files changed, 17 insertions(+)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index ed879a4d7fac..bd7adbd0339b 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2551,6 +2551,18 @@ static size_t __iommu_map_sg(struct iommu_domain
*domain, unsigned long iova,
unsigned int i = 0;
int ret;
+ if (ops->map_sg) {
+ ret = ops->map_sg(domain, iova, sg, nents, prot, gfp, &mapped);
+
+ if (ops->iotlb_sync_map)
+ ops->iotlb_sync_map(domain, iova, mapped);
+
+ if (ret)
+ goto out_err;
+
+ return mapped;
+ }
+
while (i <= nents) {
phys_addr_t s_phys = sg_phys(sg);
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index cd5f35022a25..667edc7b034a 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -192,6 +192,8 @@ struct iommu_iotlb_gather {
* @attach_dev: attach device to an iommu domain
* @detach_dev: detach device from an iommu domain
* @map: map a physically contiguous memory region to an iommu domain
+ * @map_sg: map a scatter-gather list of physically contiguous chunks to
+ * an iommu domain.
* @unmap: unmap a physically contiguous memory region from an iommu domain
* @flush_iotlb_all: Synchronously flush all hardware TLBs for this domain
* @iotlb_sync_map: Sync mappings created recently using @map to the hardware
@@ -243,6 +245,9 @@ struct iommu_ops {
void (*detach_dev)(struct iommu_domain *domain, struct device *dev);
int (*map)(struct iommu_domain *domain, unsigned long iova,
phys_addr_t paddr, size_t size, int prot, gfp_t gfp);
+ int (*map_sg)(struct iommu_domain *domain, unsigned long iova,
+ struct scatterlist *sg, unsigned int nents, int prot,
+ gfp_t gfp, size_t *mapped);
I might be oversensitive. But what if the vendor iommu driver uses iova
beyond the pre-allocated range? It's safer if we could pass an iova
length parameter as well, so that the iommu driver could do some sanity
check.
Best regards,
baolu
size_t (*unmap)(struct iommu_domain *domain, unsigned long iova,
size_t size, struct iommu_iotlb_gather *iotlb_gather);
void (*flush_iotlb_all)(struct iommu_domain *domain);
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