[PATCH v3 03/10] iommu: Add a gfp parameter to iommu_map_sg()

Jason Gunthorpe
2023-01-23T20:37:09Z

Follow the pattern for iommu_map() and remove iommu_map_sg_atomic().

This allows __iommu_dma_alloc_noncontiguous() to use a GFP_KERNEL
allocation here, based on the provided gfp flags.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
drivers/iommu/dma-iommu.c | 5 +++--
drivers/iommu/iommu.c | 26 ++++++++++----------------
include/linux/iommu.h | 18 +++++-------------
3 files changed, 18 insertions(+), 31 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 7016db569f81fc..72cfa24503b8bc 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -833,7 +833,8 @@ static struct page **__iommu_dma_alloc_noncontiguous(struct device *dev,
arch_dma_prep_coherent(sg_page(sg), sg->length);
}

- ret = iommu_map_sg_atomic(domain, iova, sgt->sgl, sgt->orig_nents, ioprot);
+ ret = iommu_map_sg(domain, iova, sgt->sgl, sgt->orig_nents, ioprot,
+ GFP_ATOMIC);
if (ret < 0 || ret < size)
goto out_free_sg;

@@ -1281,7 +1282,7 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
* We'll leave any physical concatenation to the IOMMU driver's
* implementation - it knows better than we do.
*/
- ret = iommu_map_sg_atomic(domain, iova, sg, nents, prot);
+ ret = iommu_map_sg(domain, iova, sg, nents, prot, GFP_ATOMIC);
if (ret < 0 || ret < iova_len)
goto out_free_iova;

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 9412b420d07257..cc6e7c6bf72758 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2470,9 +2470,9 @@ size_t iommu_unmap_fast(struct iommu_domain *domain,
}
EXPORT_SYMBOL_GPL(iommu_unmap_fast);

-static ssize_t __iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
- struct scatterlist *sg, unsigned int nents, int prot,
- gfp_t gfp)
+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;
@@ -2480,6 +2480,13 @@ static ssize_t __iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
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);

@@ -2519,21 +2526,8 @@ static ssize_t __iommu_map_sg(struct iommu_domain *domain, unsigned long iova,

return ret;
}
-
-ssize_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
- struct scatterlist *sg, unsigned int nents, int prot)
-{
- might_sleep();
- return __iommu_map_sg(domain, iova, sg, nents, prot, GFP_KERNEL);
-}
EXPORT_SYMBOL_GPL(iommu_map_sg);

-ssize_t iommu_map_sg_atomic(struct iommu_domain *domain, unsigned long iova,
- struct scatterlist *sg, unsigned int nents, int prot)
-{
- return __iommu_map_sg(domain, iova, sg, nents, prot, GFP_ATOMIC);
-}
-
/**
* report_iommu_fault() - report about an IOMMU fault to the IOMMU framework
* @domain: the iommu domain where the fault has happened
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 521cd79700f4d8..d5c16dc33c87de 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -474,10 +474,8 @@ extern size_t iommu_unmap_fast(struct iommu_domain *domain,
unsigned long iova, size_t size,
struct iommu_iotlb_gather *iotlb_gather);
extern ssize_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
- struct scatterlist *sg, unsigned int nents, int prot);
-extern ssize_t iommu_map_sg_atomic(struct iommu_domain *domain,
- unsigned long iova, struct scatterlist *sg,
- unsigned int nents, int prot);
+ struct scatterlist *sg, unsigned int nents,
+ int prot, gfp_t gfp);
extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova);
extern void iommu_set_fault_handler(struct iommu_domain *domain,
iommu_fault_handler_t handler, void *token);
@@ -791,14 +789,7 @@ static inline size_t iommu_unmap_fast(struct iommu_domain *domain,

static inline ssize_t iommu_map_sg(struct iommu_domain *domain,
unsigned long iova, struct scatterlist *sg,
- unsigned int nents, int prot)
-{
- return -ENODEV;
-}
-
-static inline ssize_t iommu_map_sg_atomic(struct iommu_domain *domain,
- unsigned long iova, struct scatterlist *sg,
- unsigned int nents, int prot)
+ unsigned int nents, int prot, gfp_t gfp)
{
return -ENODEV;
}
@@ -1109,7 +1100,8 @@ iommu_get_domain_for_dev_pasid(struct device *dev, ioasid_t pasid,
static inline size_t iommu_map_sgtable(struct iommu_domain *domain,
unsigned long iova, struct sg_table *sgt, int prot)
{
- return iommu_map_sg(domain, iova, sgt->sgl, sgt->orig_nents, prot);
+ return iommu_map_sg(domain, iova, sgt->sgl, sgt->orig_nents, prot,
+ GFP_KERNEL);
}

#ifdef CONFIG_IOMMU_DEBUGFS
--
2.39.0