[PATCH v2 07/13] IB/iser: Generalize fall_to_bounce_buf routine

Sagi Grimberg
2014-03-05T17:43:45Z

Unaligned SG-lists may also happen for protection
information. Genrelize bounce buffer routine to handle
any iser_data_buf which may be data and/or protection.

This patch does not change any functionality.

Signed-off-by: Sagi Grimberg <sagig-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
---
drivers/infiniband/ulp/iser/iser_memory.c | 53 ++++++++++++++++-------------
1 files changed, 29 insertions(+), 24 deletions(-)

diff --git a/drivers/infiniband/ulp/iser/iser_memory.c b/drivers/infiniband/ulp/iser/iser_memory.c
index a933508..2c3f4b1 100644
--- a/drivers/infiniband/ulp/iser/iser_memory.c
+++ b/drivers/infiniband/ulp/iser/iser_memory.c
@@ -45,13 +45,19 @@
* iser_start_rdma_unaligned_sg
*/
static int iser_start_rdma_unaligned_sg(struct iscsi_iser_task *iser_task,
+ struct iser_data_buf *data,
+ struct iser_data_buf *data_copy,
enum iser_data_dir cmd_dir)
{
- int dma_nents;
- struct ib_device *dev;
+ struct ib_device *dev = iser_task->iser_conn->ib_conn->device->ib_device;
+ struct scatterlist *sgl = (struct scatterlist *)data->buf;
+ struct scatterlist *sg;
char *mem = NULL;
- struct iser_data_buf *data = &iser_task->data[cmd_dir];
- unsigned long cmd_data_len = data->data_len;
+ unsigned long cmd_data_len = 0;
+ int dma_nents, i;
+
+ for_each_sg(sgl, sg, data->size, i)
+ cmd_data_len += ib_sg_dma_len(dev, sg);

if (cmd_data_len > ISER_KMALLOC_THRESHOLD)
mem = (void *)__get_free_pages(GFP_ATOMIC,
@@ -61,17 +67,16 @@ static int iser_start_rdma_unaligned_sg(struct iscsi_iser_task *iser_task,

if (mem == NULL) {
iser_err("Failed to allocate mem size %d %d for copying sglist\n",
- data->size,(int)cmd_data_len);
+ data->size, (int)cmd_data_len);
return -ENOMEM;
}

if (cmd_dir == ISER_DIR_OUT) {
/* copy the unaligned sg the buffer which is used for RDMA */
- struct scatterlist *sgl = (struct scatterlist *)data->buf;
- struct scatterlist *sg;
int i;
char *p, *from;

+ sgl = (struct scatterlist *)data->buf;
p = mem;
for_each_sg(sgl, sg, data->size, i) {
from = kmap_atomic(sg_page(sg));
@@ -83,22 +88,19 @@ static int iser_start_rdma_unaligned_sg(struct iscsi_iser_task *iser_task,
}
}

- sg_init_one(&iser_task->data_copy[cmd_dir].sg_single, mem, cmd_data_len);
- iser_task->data_copy[cmd_dir].buf =
- &iser_task->data_copy[cmd_dir].sg_single;
- iser_task->data_copy[cmd_dir].size = 1;
+ sg_init_one(&data_copy->sg_single, mem, cmd_data_len);
+ data_copy->buf = &data_copy->sg_single;
+ data_copy->size = 1;
+ data_copy->copy_buf = mem;

- iser_task->data_copy[cmd_dir].copy_buf = mem;
-
- dev = iser_task->iser_conn->ib_conn->device->ib_device;
- dma_nents = ib_dma_map_sg(dev,
- &iser_task->data_copy[cmd_dir].sg_single,
- 1,
+ dma_nents = ib_dma_map_sg(dev, &data_copy->sg_single, 1,
(cmd_dir == ISER_DIR_OUT) ?
DMA_TO_DEVICE : DMA_FROM_DEVICE);
BUG_ON(dma_nents == 0);

- iser_task->data_copy[cmd_dir].dma_nents = dma_nents;
+ data_copy->dma_nents = dma_nents;
+ data_copy->data_len = cmd_data_len;
+
return 0;
}

@@ -341,11 +343,12 @@ void iser_dma_unmap_task_data(struct iscsi_iser_task *iser_task,

static int fall_to_bounce_buf(struct iscsi_iser_task *iser_task,
struct ib_device *ibdev,
+ struct iser_data_buf *mem,
+ struct iser_data_buf *mem_copy,
enum iser_data_dir cmd_dir,
int aligned_len)
{
struct iscsi_conn *iscsi_conn = iser_task->iser_conn->iscsi_conn;
- struct iser_data_buf *mem = &iser_task->data[cmd_dir];

iscsi_conn->fmr_unalign_cnt++;
iser_warn("rdma alignment violation (%d/%d aligned) or FMR not supported\n",
@@ -355,12 +358,12 @@ static int fall_to_bounce_buf(struct iscsi_iser_task *iser_task,
iser_data_buf_dump(mem, ibdev);

/* unmap the command data before accessing it */
- iser_dma_unmap_task_data(iser_task, &iser_task->data[cmd_dir]);
+ iser_dma_unmap_task_data(iser_task, mem);

/* allocate copy buf, if we are writing, copy the */
/* unaligned scatterlist, dma map the copy */
- if (iser_start_rdma_unaligned_sg(iser_task, cmd_dir) != 0)
- return -ENOMEM;
+ if (iser_start_rdma_unaligned_sg(iser_task, mem, mem_copy, cmd_dir) != 0)
+ return -ENOMEM;

return 0;
}
@@ -388,7 +391,8 @@ int iser_reg_rdma_mem_fmr(struct iscsi_iser_task *iser_task,

aligned_len = iser_data_buf_aligned_len(mem, ibdev);
if (aligned_len != mem->dma_nents) {
- err = fall_to_bounce_buf(iser_task, ibdev,
+ err = fall_to_bounce_buf(iser_task, ibdev, mem,
+ &iser_task->data_copy[cmd_dir],
cmd_dir, aligned_len);
if (err) {
iser_err("failed to allocate bounce buffer\n");
@@ -536,7 +540,8 @@ int iser_reg_rdma_mem_fastreg(struct iscsi_iser_task *iser_task,

aligned_len = iser_data_buf_aligned_len(mem, ibdev);
if (aligned_len != mem->dma_nents) {
- err = fall_to_bounce_buf(iser_task, ibdev,
+ err = fall_to_bounce_buf(iser_task, ibdev, mem,
+ &iser_task->data_copy[cmd_dir],
cmd_dir, aligned_len);
if (err) {
iser_err("failed to allocate bounce buffer\n");