[PATCH v1 02/13] IB/iser: Push the desicion what memory key to use into fast_reg_mr routine

Sagi Grimberg
2014-02-27T11:12:58Z

This is a preparation step for T10-PI offload support. We prefer to push
the desicion of which mkey to use (global or fastreg) to iser_fast_reg_mr.
We choose to do this since it in T10-PI we may need to register for
protection buffers and in this case we wish to simplify iser_fast_reg_mr
instead of repeating the logic of which key to use.

This patch does not change any functionality.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Alex Tabachnik <alext@mellanox.com>
---
drivers/infiniband/ulp/iser/iser_memory.c | 101 +++++++++++++++++------------
1 files changed, 59 insertions(+), 42 deletions(-)

diff --git a/drivers/infiniband/ulp/iser/iser_memory.c b/drivers/infiniband/ulp/iser/iser_memory.c
index 6e9b7bc..d25587e 100644
--- a/drivers/infiniband/ulp/iser/iser_memory.c
+++ b/drivers/infiniband/ulp/iser/iser_memory.c
@@ -444,16 +444,40 @@ int iser_reg_rdma_mem_fmr(struct iscsi_iser_task *iser_task,
return 0;
}

-static int iser_fast_reg_mr(struct fast_reg_descriptor *desc,
- struct iser_conn *ib_conn,
+static int iser_fast_reg_mr(struct iscsi_iser_task *iser_task,
struct iser_regd_buf *regd_buf,
- u32 offset, unsigned int data_size,
- unsigned int page_list_len)
+ struct iser_data_buf *mem,
+ struct ib_sge *sge)
{
+ struct fast_reg_descriptor *desc = regd_buf->reg.mem_h;
+ struct iser_conn *ib_conn = iser_task->iser_conn->ib_conn;
+ struct iser_device *device = ib_conn->device;
+ struct ib_device *ibdev = device->ib_device;
struct ib_send_wr fastreg_wr, inv_wr;
struct ib_send_wr *bad_wr, *wr = NULL;
u8 key;
- int ret;
+ int ret, offset, size, plen;
+
+ /* if there a single dma entry, dma mr suffices */
+ if (mem->dma_nents == 1) {
+ struct scatterlist *sg = (struct scatterlist *)mem->buf;
+
+ sge->lkey = device->mr->lkey;
+ sge->addr = ib_sg_dma_address(ibdev, &sg[0]);
+ sge->length = ib_sg_dma_len(ibdev, &sg[0]);
+
+ iser_dbg("Single DMA entry: lkey=0x%x, addr=0x%llx, length=0x%x\n",
+ sge->lkey, sge->addr, sge->length);
+ return 0;
+ }
+
+ plen = iser_sg_to_page_vec(mem, device->ib_device,
+ desc->data_frpl->page_list,
+ &offset, &size);
+ if (plen * SIZE_4K < size) {
+ iser_err("fast reg page_list too short to hold this SG\n");
+ return -EINVAL;
+ }

if (!desc->valid) {
memset(&inv_wr, 0, sizeof(inv_wr));
@@ -472,9 +496,9 @@ static int iser_fast_reg_mr(struct fast_reg_descriptor *desc,
fastreg_wr.opcode = IB_WR_FAST_REG_MR;
fastreg_wr.wr.fast_reg.iova_start = desc->data_frpl->page_list[0] + offset;
fastreg_wr.wr.fast_reg.page_list = desc->data_frpl;
- fastreg_wr.wr.fast_reg.page_list_len = page_list_len;
+ fastreg_wr.wr.fast_reg.page_list_len = plen;
fastreg_wr.wr.fast_reg.page_shift = SHIFT_4K;
- fastreg_wr.wr.fast_reg.length = data_size;
+ fastreg_wr.wr.fast_reg.length = size;
fastreg_wr.wr.fast_reg.rkey = desc->data_mr->rkey;
fastreg_wr.wr.fast_reg.access_flags = (IB_ACCESS_LOCAL_WRITE |
IB_ACCESS_REMOTE_WRITE |
@@ -492,12 +516,9 @@ static int iser_fast_reg_mr(struct fast_reg_descriptor *desc,
}
desc->valid = false;

- regd_buf->reg.mem_h = desc;
- regd_buf->reg.lkey = desc->data_mr->lkey;
- regd_buf->reg.rkey = desc->data_mr->rkey;
- regd_buf->reg.va = desc->data_frpl->page_list[0] + offset;
- regd_buf->reg.len = data_size;
- regd_buf->reg.is_mr = 1;
+ sge->lkey = desc->data_mr->lkey;
+ sge->addr = desc->data_frpl->page_list[0] + offset;
+ sge->length = size;

return ret;
}
@@ -516,11 +537,10 @@ int iser_reg_rdma_mem_fastreg(struct iscsi_iser_task *iser_task,
struct ib_device *ibdev = device->ib_device;
struct iser_data_buf *mem = &iser_task->data[cmd_dir];
struct iser_regd_buf *regd_buf = &iser_task->rdma_regd[cmd_dir];
- struct fast_reg_descriptor *desc;
- unsigned int data_size, page_list_len;
+ struct fast_reg_descriptor *desc = NULL;
+ struct ib_sge data_sge;
int err, aligned_len;
unsigned long flags;
- u32 offset;

aligned_len = iser_data_buf_aligned_len(mem, ibdev);
if (aligned_len != mem->dma_nents) {
@@ -533,41 +553,38 @@ int iser_reg_rdma_mem_fastreg(struct iscsi_iser_task *iser_task,
mem = &iser_task->data_copy[cmd_dir];
}

- /* if there a single dma entry, dma mr suffices */
- if (mem->dma_nents == 1) {
- struct scatterlist *sg = (struct scatterlist *)mem->buf;
-
- regd_buf->reg.lkey = device->mr->lkey;
- regd_buf->reg.rkey = device->mr->rkey;
- regd_buf->reg.len = ib_sg_dma_len(ibdev, &sg[0]);
- regd_buf->reg.va = ib_sg_dma_address(ibdev, &sg[0]);
- regd_buf->reg.is_mr = 0;
- } else {
+ if (mem->dma_nents != 1) {
spin_lock_irqsave(&ib_conn->lock, flags);
desc = list_first_entry(&ib_conn->fastreg.pool,
struct fast_reg_descriptor, list);
list_del(&desc->list);
spin_unlock_irqrestore(&ib_conn->lock, flags);
- page_list_len = iser_sg_to_page_vec(mem, device->ib_device,
- desc->data_frpl->page_list,
- &offset, &data_size);
-
- if (page_list_len * SIZE_4K < data_size) {
- iser_err("fast reg page_list too short to hold this SG\n");
- err = -EINVAL;
- goto err_reg;
- }
+ regd_buf->reg.mem_h = desc;
+ }

- err = iser_fast_reg_mr(desc, ib_conn, regd_buf,
- offset, data_size, page_list_len);
- if (err)
- goto err_reg;
+ err = iser_fast_reg_mr(iser_task, regd_buf, mem, &data_sge);
+ if (err)
+ goto err_reg;
+
+ if (desc) {
+ regd_buf->reg.rkey = desc->data_mr->rkey;
+ regd_buf->reg.is_mr = 1;
+ } else {
+ regd_buf->reg.rkey = device->mr->rkey;
+ regd_buf->reg.is_mr = 0;
}

+ regd_buf->reg.lkey = data_sge.lkey;
+ regd_buf->reg.va = data_sge.addr;
+ regd_buf->reg.len = data_sge.length;
+
return 0;
err_reg:
- spin_lock_irqsave(&ib_conn->lock, flags);
- list_add_tail(&desc->list, &ib_conn->fastreg.pool);
- spin_unlock_irqrestore(&ib_conn->lock, flags);
+ if (desc) {
+ spin_lock_irqsave(&ib_conn->lock, flags);
+ list_add_tail(&desc->list, &ib_conn->fastreg.pool);
+ spin_unlock_irqrestore(&ib_conn->lock, flags);
+ }
+
return err;
}
--
1.7.1