[PATCH v3 03/17] iommu: generalize the batched sync after map interface

Leon Romanovsky
2024-11-10T13:47:30Z

From: Christoph Hellwig <hch@lst.de>

For the upcoming IOVA-based DMA API we want to use the interface batch the
sync after mapping multiple entries from dma-iommu without having a
scatterlist.

For that move more sanity checks from the callers into __iommu_map and
make that function available outside of iommu.c as iommu_map_nosync.

Add a wrapper for the map_sync as iommu_sync_map so that callers don't
need to poke into the methods directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
drivers/iommu/iommu.c | 65 +++++++++++++++++++------------------------
include/linux/iommu.h | 4 +++
2 files changed, 33 insertions(+), 36 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 83c8e617a2c5..6b0943397e1e 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2439,8 +2439,8 @@ static size_t iommu_pgsize(struct iommu_domain *domain, unsigned long iova,
return pgsize;
}

-static int __iommu_map(struct iommu_domain *domain, unsigned long iova,
- phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
+int iommu_map_nosync(struct iommu_domain *domain, unsigned long iova,
+ phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
{
const struct iommu_domain_ops *ops = domain->ops;
unsigned long orig_iova = iova;
@@ -2449,12 +2449,19 @@ static int __iommu_map(struct iommu_domain *domain, unsigned long iova,
phys_addr_t orig_paddr = paddr;
int ret = 0;

+ might_sleep_if(gfpflags_allow_blocking(gfp));
+
if (unlikely(!(domain->type & __IOMMU_DOMAIN_PAGING)))
return -EINVAL;

if (WARN_ON(!ops->map_pages || domain->pgsize_bitmap == 0UL))
return -ENODEV;

+ /* Discourage passing strange GFP flags */
+ if (WARN_ON_ONCE(gfp & (__GFP_COMP | __GFP_DMA | __GFP_DMA32 |
+ __GFP_HIGHMEM)))
+ return -EINVAL;
+
/* find out the minimum page size supported */
min_pagesz = 1 << __ffs(domain->pgsize_bitmap);

@@ -2502,31 +2509,27 @@ static int __iommu_map(struct iommu_domain *domain, unsigned long iova,
return ret;
}

-int iommu_map(struct iommu_domain *domain, unsigned long iova,
- phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
+int iommu_sync_map(struct iommu_domain *domain, unsigned long iova, size_t size)
{
const struct iommu_domain_ops *ops = domain->ops;
- int ret;
-
- might_sleep_if(gfpflags_allow_blocking(gfp));

- /* Discourage passing strange GFP flags */
- if (WARN_ON_ONCE(gfp & (__GFP_COMP | __GFP_DMA | __GFP_DMA32 |
- __GFP_HIGHMEM)))
- return -EINVAL;
+ if (!ops->iotlb_sync_map)
+ return 0;
+ return ops->iotlb_sync_map(domain, iova, size);
+}

- ret = __iommu_map(domain, iova, paddr, size, prot, gfp);
- if (ret == 0 && ops->iotlb_sync_map) {
- ret = ops->iotlb_sync_map(domain, iova, size);
- if (ret)
- goto out_err;
- }
+int iommu_map(struct iommu_domain *domain, unsigned long iova,
+ phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
+{
+ int ret;

- return ret;
+ ret = iommu_map_nosync(domain, iova, paddr, size, prot, gfp);
+ if (ret)
+ return ret;

-out_err:
- /* undo mappings already done */
- iommu_unmap(domain, iova, size);
+ ret = iommu_sync_map(domain, iova, size);
+ if (ret)
+ iommu_unmap(domain, iova, size);

return ret;
}
@@ -2612,26 +2615,17 @@ ssize_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
struct scatterlist *sg, unsigned int nents, int prot,
gfp_t gfp)
{
- const struct iommu_domain_ops *ops = domain->ops;
size_t len = 0, mapped = 0;
phys_addr_t start;
unsigned int i = 0;
int ret;

- might_sleep_if(gfpflags_allow_blocking(gfp));
-
- /* Discourage passing strange GFP flags */
- if (WARN_ON_ONCE(gfp & (__GFP_COMP | __GFP_DMA | __GFP_DMA32 |
- __GFP_HIGHMEM)))
- return -EINVAL;
-
while (i <= nents) {
phys_addr_t s_phys = sg_phys(sg);

if (len && s_phys != start + len) {
- ret = __iommu_map(domain, iova + mapped, start,
+ ret = iommu_map_nosync(domain, iova + mapped, start,
len, prot, gfp);
-
if (ret)
goto out_err;

@@ -2654,11 +2648,10 @@ ssize_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
sg = sg_next(sg);
}

- if (ops->iotlb_sync_map) {
- ret = ops->iotlb_sync_map(domain, iova, mapped);
- if (ret)
- goto out_err;
- }
+ ret = iommu_sync_map(domain, iova, mapped);
+ if (ret)
+ goto out_err;
+
return mapped;

out_err:
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index bd722f473635..8927e5f996c2 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -799,6 +799,10 @@ extern struct iommu_domain *iommu_get_domain_for_dev(struct device *dev);
extern struct iommu_domain *iommu_get_dma_domain(struct device *dev);
extern int iommu_map(struct iommu_domain *domain, unsigned long iova,
phys_addr_t paddr, size_t size, int prot, gfp_t gfp);
+int iommu_map_nosync(struct iommu_domain *domain, unsigned long iova,
+ phys_addr_t paddr, size_t size, int prot, gfp_t gfp);
+int iommu_sync_map(struct iommu_domain *domain, unsigned long iova,
+ size_t size);
extern size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova,
size_t size);
extern size_t iommu_unmap_fast(struct iommu_domain *domain,
--
2.47.0