ib_num_pages() should only be used by things working with the SGL in CPU
pages directly.
Drivers building DMA lists should use the new ib_num_dma_blocks() which
returns the number of blocks rdma_umem_for_each_block() will return.
To make this general for DMA drivers requires a different implementation.
Computing DMA block count based on umem->address only works if the
requested page size is < PAGE_SIZE and/or the IOVA == umem->address.
Instead the number of DMA pages should be computed in the IOVA address
space, not umem->address. Thus the IOVA has to be stored inside the umem
so it can be used for these calculations.
For now set it to umem->address by default and fix it up if
ib_umem_find_best_pgsz() was called. This allows drivers to be converted
to ib_umem_num_dma_blocks() safely.
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
---
drivers/infiniband/core/umem.c | 7 ++++++-
drivers/infiniband/hw/cxgb4/mem.c | 2 +-
drivers/infiniband/hw/mlx5/mem.c | 4 ++--
drivers/infiniband/hw/mthca/mthca_provider.c | 2 +-
drivers/infiniband/hw/vmw_pvrdma/pvrdma_mr.c | 2 +-
include/rdma/ib_umem.h | 15 ++++++++++++---
6 files changed, 23 insertions(+), 9 deletions(-)
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index fb7630e7aac3a7..b57dbb14de8378 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -161,7 +161,7 @@ unsigned long ib_umem_find_best_pgsz(struct ib_umem *umem,
if (WARN_ON(!(pgsz_bitmap & GENMASK(PAGE_SHIFT, 0))))
return 0;
- va = virt;
+ umem->iova = va = virt;
/* The best result is the smallest page size that results in the minimum
* number of required pages. Compute the largest page size that could
* work based on VA address bits that don't change.
@@ -240,6 +240,11 @@ struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,
umem->ibdev = device;
umem->length = size;
umem->address = addr;
+ /*
+ * Drivers should call ib_umem_find_best_pgsz() to set the iova
+ * correctly.
+ */
+ umem->iova = addr;
umem->writable = ib_access_writable(access);
umem->owning_mm = mm = current->mm;
mmgrab(mm);
diff --git a/drivers/infiniband/hw/cxgb4/mem.c b/drivers/infiniband/hw/cxgb4/mem.c
index 82afdb1987eff6..22c8f5745047db 100644
--- a/drivers/infiniband/hw/cxgb4/mem.c
+++ b/drivers/infiniband/hw/cxgb4/mem.c
@@ -548,7 +548,7 @@ struct ib_mr *c4iw_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
shift = PAGE_SHIFT;
- n = ib_umem_num_pages(mhp->umem);
+ n = ib_umem_num_dma_blocks(mhp->umem, 1 << shift);
err = alloc_pbl(mhp, n);
if (err)
goto err_umem_release;
diff --git a/drivers/infiniband/hw/mlx5/mem.c b/drivers/infiniband/hw/mlx5/mem.c
index c19ec9fd8a63c3..13de3d2edd34e3 100644
--- a/drivers/infiniband/hw/mlx5/mem.c
+++ b/drivers/infiniband/hw/mlx5/mem.c
@@ -169,8 +169,8 @@ void mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem,
int page_shift, __be64 *pas, int access_flags)
{
return __mlx5_ib_populate_pas(dev, umem, page_shift, 0,
- ib_umem_num_pages(umem), pas,
- access_flags);
+ ib_umem_num_dma_blocks(umem, PAGE_SIZE),
+ pas, access_flags);
}
int mlx5_ib_get_buf_offset(u64 addr, int page_shift, u32 *offset)
{
diff --git a/drivers/infiniband/hw/mthca/mthca_provider.c b/drivers/infiniband/hw/mthca/mthca_provider.c
index 317e67ad915fe8..b785fb9a2634ff 100644
--- a/drivers/infiniband/hw/mthca/mthca_provider.c
+++ b/drivers/infiniband/hw/mthca/mthca_provider.c
@@ -877,7 +877,7 @@ static struct ib_mr *mthca_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
goto err;
}
- n = ib_umem_num_pages(mr->umem);
+ n = ib_umem_num_dma_blocks(mr->umem, PAGE_SIZE);
mr->mtt = mthca_alloc_mtt(dev, n);
if (IS_ERR(mr->mtt)) {
diff --git a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_mr.c b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_mr.c
index 91f0957e611543..e80848bfb3bdbf 100644
--- a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_mr.c
+++ b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_mr.c
@@ -133,7 +133,7 @@ struct ib_mr *pvrdma_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
return ERR_CAST(umem);
}
- npages = ib_umem_num_pages(umem);
+ npages = ib_umem_num_dma_blocks(umem, PAGE_SIZE);
if (npages < 0 || npages > PVRDMA_PAGE_DIR_MAX_PAGES) {
dev_warn(&dev->pdev->dev, "overflow %d pages in mem region\n",
npages);
diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h
index b880512ba95f16..0f1ab3d8f77dea 100644
--- a/include/rdma/ib_umem.h
+++ b/include/rdma/ib_umem.h
@@ -17,6 +17,7 @@ struct ib_umem_odp;
struct ib_umem {
struct ib_device *ibdev;
struct mm_struct *owning_mm;
+ u64 iova;
size_t length;
unsigned long address;
u32 writable : 1;
@@ -33,11 +34,17 @@ static inline int ib_umem_offset(struct ib_umem *umem)
return umem->address & ~PAGE_MASK;
}
+static inline size_t ib_umem_num_dma_blocks(struct ib_umem *umem,
+ unsigned long pgsz)
+{
+ return (ALIGN(umem->iova + umem->length, pgsz) -
+ ALIGN_DOWN(umem->iova, pgsz)) /
+ pgsz;
+}
+
static inline size_t ib_umem_num_pages(struct ib_umem *umem)
{
- return (ALIGN(umem->address + umem->length, PAGE_SIZE) -
- ALIGN_DOWN(umem->address, PAGE_SIZE)) >>
- PAGE_SHIFT;
+ return ib_umem_num_dma_blocks(umem, PAGE_SIZE);
}
static inline void __rdma_umem_block_iter_start(struct ib_block_iter *biter,
@@ -55,6 +62,8 @@ static inline void __rdma_umem_block_iter_start(struct ib_block_iter *biter,
* pgsz must be <= PAGE_SIZE or computed by ib_umem_find_best_pgsz(). The
* returned DMA blocks will be aligned to pgsz and span the range:
* ALIGN_DOWN(umem->address, pgsz) to ALIGN(umem->address + umem->length, pgsz)
+ *
+ * Performs exactly ib_umem_num_dma_blocks() iterations.
*/
#define rdma_umem_for_each_dma_block(umem, biter, pgsz) \
for (__rdma_umem_block_iter_start(biter, umem, pgsz); \
--
2.28.0
