2022-11-11 04:44:14

by Li Zhijian

Subject: [for-next PATCH 2/5] RDMA/rxe: use iova_to_vaddr to transform iova for rxe_mr_copy

Make the code more friendly and readable by using iova_to_vaddr()

This commit also remove the err1 label in rxe_mr_copy().

Signed-off-by: Li Zhijian <[email protected]>
---
drivers/infiniband/sw/rxe/rxe_mr.c | 46 +++++++++---------------------
1 file changed, 13 insertions(+), 33 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c b/drivers/infiniband/sw/rxe/rxe_mr.c
index f6366a635b92..cf3ce8d293b3 100644
--- a/drivers/infiniband/sw/rxe/rxe_mr.c
+++ b/drivers/infiniband/sw/rxe/rxe_mr.c
@@ -289,13 +289,6 @@ void *iova_to_vaddr(struct rxe_mr *mr, u64 iova, int length)
int rxe_mr_copy(struct rxe_mr *mr, u64 iova, void *addr, int length,
enum rxe_mr_copy_dir dir)
{
- int err;
- int bytes;
- u8 *va;
- struct rxe_map **map;
- struct rxe_phys_buf *buf;
- int m;
- int i;
size_t offset;

if (length == 0)
@@ -315,49 +308,36 @@ int rxe_mr_copy(struct rxe_mr *mr, u64 iova, void *addr, int length,

WARN_ON_ONCE(!mr->map);

- err = mr_check_range(mr, iova, length);
- if (err) {
- err = -EFAULT;
- goto err1;
- }
-
- lookup_iova(mr, iova, &m, &i, &offset);
-
- map = mr->map + m;
- buf = map[0]->buf + i;
+ if (mr_check_range(mr, iova, length))
+ return -EFAULT;

+ offset = (iova - mr->ibmr.iova + mr->offset) & mr->page_mask;
while (length > 0) {
- u8 *src, *dest;
-
- va = (u8 *)(uintptr_t)buf->addr + offset;
- src = (dir == RXE_TO_MR_OBJ) ? addr : va;
- dest = (dir == RXE_TO_MR_OBJ) ? va : addr;
+ u8 *src, *dest, *va;
+ int bytes;

bytes = mr->ibmr.page_size - offset;

if (bytes > length)
bytes = length;

+ va = iova_to_vaddr(mr, iova, bytes);
+ if (!va)
+ return -EFAULT;
+
+ src = (dir == RXE_TO_MR_OBJ) ? addr : va;
+ dest = (dir == RXE_TO_MR_OBJ) ? va : addr;
+
memcpy(dest, src, bytes);

length -= bytes;
addr += bytes;
+ iova += bytes;

offset = 0;
- buf++;
- i++;
-
- if (i == RXE_BUF_PER_MAP) {
- i = 0;
- map++;
- buf = map[0]->buf;
- }
}

return 0;
-
-err1:
- return err;
}

/* copy data in or out of a wqe, i.e. sg list
--
2.31.1

2022-11-18 17:29:59

by Jason Gunthorpe

Subject: Re: [for-next PATCH 2/5] RDMA/rxe: use iova_to_vaddr to transform iova for rxe_mr_copy

On Fri, Nov 11, 2022 at 04:30:27AM +0000, Li Zhijian wrote:
> Make the code more friendly and readable by using iova_to_vaddr()

But the point of this is to be faster because it knows pages are in a
linear list

As with my previous suggestion, just convert this to an xarray and
then it is a trivial and fast xas_for_each_range() returning struct
pages.

Jason