IB/srp: Cache global rkey

This is a micro-optimization for the hot path.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.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 96750ad..463c3ed 100644 (file)
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -1292,7 +1292,6 @@ static int srp_map_finish_fmr(struct srp_map_state *state,
 {
        struct srp_target_port *target = ch->target;
        struct srp_device *dev = target->srp_host->srp_dev;
-       struct ib_pd *pd = target->pd;
        struct ib_pool_fmr *fmr;
        u64 io_addr = 0;
 
@@ -1308,9 +1307,9 @@ static int srp_map_finish_fmr(struct srp_map_state *state,
        if (state->npages == 0)
                return 0;
 
-       if (state->npages == 1 && (pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY)) {
+       if (state->npages == 1 && target->global_rkey) {
                srp_map_desc(state, state->base_dma_addr, state->dma_len,
-                            pd->unsafe_global_rkey);
+                            target->global_rkey);
                goto reset_state;
        }
 
@@ -1350,7 +1349,6 @@ static int srp_map_finish_fr(struct srp_map_state *state,
 {
        struct srp_target_port *target = ch->target;
        struct srp_device *dev = target->srp_host->srp_dev;
-       struct ib_pd *pd = target->pd;
        struct ib_send_wr *bad_wr;
        struct ib_reg_wr wr;
        struct srp_fr_desc *desc;
@@ -1366,12 +1364,12 @@ static int srp_map_finish_fr(struct srp_map_state *state,
 
        WARN_ON_ONCE(!dev->use_fast_reg);
 
-       if (sg_nents == 1 && (pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY)) {
+       if (sg_nents == 1 && target->global_rkey) {
                unsigned int sg_offset = sg_offset_p ? *sg_offset_p : 0;
 
                srp_map_desc(state, sg_dma_address(state->sg) + sg_offset,
                             sg_dma_len(state->sg) - sg_offset,
-                            pd->unsafe_global_rkey);
+                            target->global_rkey);
                if (sg_offset_p)
                        *sg_offset_p = 0;
                return 1;
@@ -1533,7 +1531,7 @@ static int srp_map_sg_dma(struct srp_map_state *state, struct srp_rdma_ch *ch,
        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->pd->unsafe_global_rkey);
+                            target->global_rkey);
        }
 
        return 0;
@@ -1631,7 +1629,6 @@ static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_rdma_ch *ch,
                        struct srp_request *req)
 {
        struct srp_target_port *target = ch->target;
-       struct ib_pd *pd = target->pd;
        struct scatterlist *scat;
        struct srp_cmd *cmd = req->cmd->buf;
        int len, nents, count, ret;
@@ -1667,7 +1664,7 @@ static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_rdma_ch *ch,
        fmt = SRP_DATA_DESC_DIRECT;
        len = sizeof (struct srp_cmd) + sizeof (struct srp_direct_buf);
 
-       if (count == 1 && (pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY)) {
+       if (count == 1 && target->global_rkey) {
                /*
                 * The midlayer only generated a single gather/scatter
                 * entry, or DMA mapping coalesced everything to a
@@ -1677,7 +1674,7 @@ static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_rdma_ch *ch,
                struct srp_direct_buf *buf = (void *) cmd->add_data;
 
                buf->va  = cpu_to_be64(ib_sg_dma_address(ibdev, scat));
-               buf->key = cpu_to_be32(pd->unsafe_global_rkey);
+               buf->key = cpu_to_be32(target->global_rkey);
                buf->len = cpu_to_be32(ib_sg_dma_len(ibdev, scat));
 
                req->nmdesc = 0;
@@ -1748,14 +1745,14 @@ static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_rdma_ch *ch,
        memcpy(indirect_hdr->desc_list, req->indirect_desc,
               count * sizeof (struct srp_direct_buf));
 
-       if (!(pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY)) {
+       if (!target->global_rkey) {
                ret = srp_map_idb(ch, req, state.gen.next, state.gen.end,
                                  idb_len, &idb_rkey);
                if (ret < 0)
                        goto unmap;
                req->nmdesc++;
        } else {
-               idb_rkey = cpu_to_be32(pd->unsafe_global_rkey);
+               idb_rkey = cpu_to_be32(target->global_rkey);
        }
 
        indirect_hdr->table_desc.va = cpu_to_be64(req->indirect_dma_addr);
@@ -3331,8 +3328,8 @@ static ssize_t srp_create_target(struct device *dev,
        target->io_class        = SRP_REV16A_IB_IO_CLASS;
        target->scsi_host       = target_host;
        target->srp_host        = host;
-       target->pd              = host->srp_dev->pd;
        target->lkey            = host->srp_dev->pd->local_dma_lkey;
+       target->global_rkey     = host->srp_dev->global_rkey;
        target->cmd_sg_cnt      = cmd_sg_entries;
        target->sg_tablesize    = indirect_sg_entries ? : cmd_sg_entries;
        target->allow_ext_sg    = allow_ext_sg;
@@ -3651,6 +3648,10 @@ static void srp_add_one(struct ib_device *device)
        if (IS_ERR(srp_dev->pd))
                goto free_dev;
 
+       if (flags & IB_PD_UNSAFE_GLOBAL_RKEY) {
+               srp_dev->global_rkey = srp_dev->pd->unsafe_global_rkey;
+               WARN_ON_ONCE(srp_dev->global_rkey == 0);
+       }
 
        for (p = rdma_start_port(device); p <= rdma_end_port(device); ++p) {
                host = srp_add_port(srp_dev, p);

diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h
index ab9077b..a814f5e 100644 (file)
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -90,6 +90,7 @@ struct srp_device {
        struct list_head        dev_list;
        struct ib_device       *dev;
        struct ib_pd           *pd;
+       u32                     global_rkey;
        u64                     mr_page_mask;
        int                     mr_page_size;
        int                     mr_max_size;
@@ -179,7 +180,7 @@ struct srp_target_port {
        spinlock_t              lock;
 
        /* read only in the hot path */
-       struct ib_pd            *pd;
+       u32                     global_rkey;
        struct srp_rdma_ch      *ch;
        u32                     ch_count;
        u32                     lkey;