IB/srp: Introduce srp_map_fmr()

This patch does not change any functionality.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
This commit is contained in:
Bart Van Assche 2014-05-20 15:05:21 +02:00 committed by Roland Dreier
parent 62154b2e89
commit 76bc1e1ddd
1 changed files with 45 additions and 32 deletions

View File

@ -1047,12 +1047,54 @@ static int srp_map_sg_entry(struct srp_map_state *state,
return ret;
}
static void srp_map_fmr(struct srp_map_state *state,
struct srp_target_port *target, struct srp_request *req,
struct scatterlist *scat, int count)
{
struct srp_device *dev = target->srp_host->srp_dev;
struct ib_device *ibdev = dev->dev;
struct scatterlist *sg;
int i, use_fmr;
state->desc = req->indirect_desc;
state->pages = req->map_page;
state->next_fmr = req->fmr_list;
use_fmr = dev->fmr_pool ? SRP_MAP_ALLOW_FMR : SRP_MAP_NO_FMR;
for_each_sg(scat, sg, count, i) {
if (srp_map_sg_entry(state, target, sg, i, use_fmr)) {
/* FMR mapping failed, so backtrack to the first
* unmapped entry and continue on without using FMR.
*/
dma_addr_t dma_addr;
unsigned int dma_len;
backtrack:
sg = state->unmapped_sg;
i = state->unmapped_index;
dma_addr = ib_sg_dma_address(ibdev, sg);
dma_len = ib_sg_dma_len(ibdev, sg);
dma_len -= (state->unmapped_addr - dma_addr);
dma_addr = state->unmapped_addr;
use_fmr = SRP_MAP_NO_FMR;
srp_map_desc(state, dma_addr, dma_len, target->rkey);
}
}
if (use_fmr == SRP_MAP_ALLOW_FMR && srp_map_finish_fmr(state, target))
goto backtrack;
req->nfmr = state->nfmr;
}
static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_target_port *target,
struct srp_request *req)
{
struct scatterlist *scat, *sg;
struct scatterlist *scat;
struct srp_cmd *cmd = req->cmd->buf;
int i, len, nents, count, use_fmr;
int len, nents, count;
struct srp_device *dev;
struct ib_device *ibdev;
struct srp_map_state state;
@ -1111,35 +1153,7 @@ static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_target_port *target,
target->indirect_size, DMA_TO_DEVICE);
memset(&state, 0, sizeof(state));
state.desc = req->indirect_desc;
state.pages = req->map_page;
state.next_fmr = req->fmr_list;
use_fmr = dev->fmr_pool ? SRP_MAP_ALLOW_FMR : SRP_MAP_NO_FMR;
for_each_sg(scat, sg, count, i) {
if (srp_map_sg_entry(&state, target, sg, i, use_fmr)) {
/* FMR mapping failed, so backtrack to the first
* unmapped entry and continue on without using FMR.
*/
dma_addr_t dma_addr;
unsigned int dma_len;
backtrack:
sg = state.unmapped_sg;
i = state.unmapped_index;
dma_addr = ib_sg_dma_address(ibdev, sg);
dma_len = ib_sg_dma_len(ibdev, sg);
dma_len -= (state.unmapped_addr - dma_addr);
dma_addr = state.unmapped_addr;
use_fmr = SRP_MAP_NO_FMR;
srp_map_desc(&state, dma_addr, dma_len, target->rkey);
}
}
if (use_fmr == SRP_MAP_ALLOW_FMR && srp_map_finish_fmr(&state, target))
goto backtrack;
srp_map_fmr(&state, target, req, scat, count);
/* We've mapped the request, now pull as much of the indirect
* descriptor table as we can into the command buffer. If this
@ -1147,7 +1161,6 @@ static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_target_port *target,
* guaranteed to fit into the command, as the SCSI layer won't
* give us more S/G entries than we allow.
*/
req->nfmr = state.nfmr;
if (state.ndesc == 1) {
/* FMR mapping was able to collapse this to one entry,
* so use a direct descriptor.