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Commit 76bc1e1d authored by Bart Van Assche's avatar Bart Van Assche Committed by Roland Dreier
Browse files

IB/srp: Introduce srp_map_fmr() 



This patch does not change any functionality.

Signed-off-by: default avatarBart Van Assche <bvanassche@acm.org>
Reviewed-by: default avatarSagi Grimberg <sagig@mellanox.com>
Signed-off-by: default avatarRoland Dreier <roland@purestorage.com>
parent 62154b2e

drivers/infiniband/ulp/srp/ib_srp.c

+45 −32
Original line number Diff line number Diff line
@@ -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 @@ backtrack: 
	 * 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.