IB/srp: Split srp_map_sg

This is a preparation patch for the new registration API
conversion. It splits srp_map_sg per registration strategy
(srp_map_sg[fmr|fr|dma]. On its own it adds some code duplication,
but it makes the API switch easier to comprehend.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Tested-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 235f9b8..ef1575d 100644 (file)
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -1286,6 +1286,17 @@ static int srp_map_finish_fmr(struct srp_map_state *state,
        if (state->fmr.next >= state->fmr.end)
                return -ENOMEM;
 
+       WARN_ON_ONCE(!dev->use_fmr);
+
+       if (state->npages == 0)
+               return 0;
+
+       if (state->npages == 1 && target->global_mr) {
+               srp_map_desc(state, state->base_dma_addr, state->dma_len,
+                            target->global_mr->rkey);
+               goto reset_state;
+       }
+
        fmr = ib_fmr_pool_map_phys(ch->fmr_pool, state->pages,
                                   state->npages, io_addr);
        if (IS_ERR(fmr))
@@ -1297,6 +1308,10 @@ static int srp_map_finish_fmr(struct srp_map_state *state,
        srp_map_desc(state, state->base_dma_addr & ~dev->mr_page_mask,
                     state->dma_len, fmr->fmr->rkey);
 
+reset_state:
+       state->npages = 0;
+       state->dma_len = 0;
+
        return 0;
 }
 
@@ -1309,10 +1324,22 @@ static int srp_map_finish_fr(struct srp_map_state *state,
        struct ib_fast_reg_wr wr;
        struct srp_fr_desc *desc;
        u32 rkey;
+       int err;
 
        if (state->fr.next >= state->fr.end)
                return -ENOMEM;
 
+       WARN_ON_ONCE(!dev->use_fast_reg);
+
+       if (state->npages == 0)
+               return 0;
+
+       if (state->npages == 1 && target->global_mr) {
+               srp_map_desc(state, state->base_dma_addr, state->dma_len,
+                            target->global_mr->rkey);
+               goto reset_state;
+       }
+
        desc = srp_fr_pool_get(ch->fr_pool);
        if (!desc)
                return -ENOMEM;
@@ -1342,7 +1369,15 @@ static int srp_map_finish_fr(struct srp_map_state *state,
        srp_map_desc(state, state->base_dma_addr, state->dma_len,
                     desc->mr->rkey);
 
-       return ib_post_send(ch->qp, &wr.wr, &bad_wr);
+       err = ib_post_send(ch->qp, &wr.wr, &bad_wr);
+       if (err)
+               return err;
+
+reset_state:
+       state->npages = 0;
+       state->dma_len = 0;
+
+       return 0;
 }
 
 static int srp_finish_mapping(struct srp_map_state *state,
@@ -1350,26 +1385,9 @@ static int srp_finish_mapping(struct srp_map_state *state,
 {
        struct srp_target_port *target = ch->target;
        struct srp_device *dev = target->srp_host->srp_dev;
-       int ret = 0;
 
-       WARN_ON_ONCE(!dev->use_fast_reg && !dev->use_fmr);
-
-       if (state->npages == 0)
-               return 0;
-
-       if (state->npages == 1 && target->global_mr)
-               srp_map_desc(state, state->base_dma_addr, state->dma_len,
-                            target->global_mr->rkey);
-       else
-               ret = dev->use_fast_reg ? srp_map_finish_fr(state, ch) :
-                       srp_map_finish_fmr(state, ch);
-
-       if (ret == 0) {
-               state->npages = 0;
-               state->dma_len = 0;
-       }
-
-       return ret;
+       return dev->use_fast_reg ? srp_map_finish_fr(state, ch) :
+                                  srp_map_finish_fmr(state, ch);
 }
 
 static int srp_map_sg_entry(struct srp_map_state *state,
@@ -1415,47 +1433,79 @@ static int srp_map_sg_entry(struct srp_map_state *state,
        return ret;
 }
 
-static int srp_map_sg(struct srp_map_state *state, struct srp_rdma_ch *ch,
-                     struct srp_request *req, struct scatterlist *scat,
-                     int count)
+static int srp_map_sg_fmr(struct srp_map_state *state, struct srp_rdma_ch *ch,
+                         struct srp_request *req, struct scatterlist *scat,
+                         int count)
 {
-       struct srp_target_port *target = ch->target;
-       struct srp_device *dev = target->srp_host->srp_dev;
        struct scatterlist *sg;
        int i, ret;
 
-       state->desc     = req->indirect_desc;
-       state->pages    = req->map_page;
-       if (dev->use_fast_reg) {
-               state->fr.next = req->fr_list;
-               state->fr.end = req->fr_list + target->cmd_sg_cnt;
-       } else if (dev->use_fmr) {
-               state->fmr.next = req->fmr_list;
-               state->fmr.end = req->fmr_list + target->cmd_sg_cnt;
+       state->desc = req->indirect_desc;
+       state->pages = req->map_page;
+       state->fmr.next = req->fmr_list;
+       state->fmr.end = req->fmr_list + ch->target->cmd_sg_cnt;
+
+       for_each_sg(scat, sg, count, i) {
+               ret = srp_map_sg_entry(state, ch, sg, i);
+               if (ret)
+                       return ret;
        }
 
-       if (dev->use_fast_reg || dev->use_fmr) {
-               for_each_sg(scat, sg, count, i) {
-                       ret = srp_map_sg_entry(state, ch, sg, i);
-                       if (ret)
-                               goto out;
-               }
-               ret = srp_finish_mapping(state, ch);
+       ret = srp_finish_mapping(state, ch);
+       if (ret)
+               return ret;
+
+       req->nmdesc = state->nmdesc;
+
+       return 0;
+}
+
+static int srp_map_sg_fr(struct srp_map_state *state, struct srp_rdma_ch *ch,
+                        struct srp_request *req, struct scatterlist *scat,
+                        int count)
+{
+       struct scatterlist *sg;
+       int i, ret;
+
+       state->desc = req->indirect_desc;
+       state->pages = req->map_page;
+       state->fmr.next = req->fmr_list;
+       state->fmr.end = req->fmr_list + ch->target->cmd_sg_cnt;
+
+       for_each_sg(scat, sg, count, i) {
+               ret = srp_map_sg_entry(state, ch, sg, i);
                if (ret)
-                       goto out;
-       } else {
-               for_each_sg(scat, sg, count, i) {
-                       srp_map_desc(state, ib_sg_dma_address(dev->dev, sg),
-                                    ib_sg_dma_len(dev->dev, sg),
-                                    target->global_mr->rkey);
-               }
+                       return ret;
        }
 
+       ret = srp_finish_mapping(state, ch);
+       if (ret)
+               return ret;
+
        req->nmdesc = state->nmdesc;
-       ret = 0;
 
-out:
-       return ret;
+       return 0;
+}
+
+static int srp_map_sg_dma(struct srp_map_state *state, struct srp_rdma_ch *ch,
+                         struct srp_request *req, struct scatterlist *scat,
+                         int count)
+{
+       struct srp_target_port *target = ch->target;
+       struct srp_device *dev = target->srp_host->srp_dev;
+       struct scatterlist *sg;
+       int i;
+
+       state->desc = req->indirect_desc;
+       for_each_sg(scat, sg, count, i) {
+               srp_map_desc(state, ib_sg_dma_address(dev->dev, sg),
+                            ib_sg_dma_len(dev->dev, sg),
+                            target->global_mr->rkey);
+       }
+
+       req->nmdesc = state->nmdesc;
+
+       return 0;
 }
 
 /*
@@ -1563,7 +1613,12 @@ static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_rdma_ch *ch,
                                   target->indirect_size, DMA_TO_DEVICE);
 
        memset(&state, 0, sizeof(state));
-       srp_map_sg(&state, ch, req, scat, count);
+       if (dev->use_fast_reg)
+               srp_map_sg_fr(&state, ch, req, scat, count);
+       else if (dev->use_fmr)
+               srp_map_sg_fmr(&state, ch, req, scat, count);
+       else
+               srp_map_sg_dma(&state, ch, 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