IB/srp: try to use larger FMR sizes to cover our mappings

Now that we can get larger SG lists, we can take advantage of HCAs that
allow us to use larger FMR sizes. In many cases, we can use up to 512
entries, so start there and work our way down.

Signed-off-by: David Dillow <dillowda@ornl.gov>

2 files changed, 21 insertions, 13 deletions

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 4ec7dddbbf49..376d640487d2 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -2300,7 +2300,7 @@ static void srp_add_one(struct ib_device *device)
         struct ib_device_attr *dev_attr;
         struct ib_fmr_pool_param fmr_param;
         struct srp_host *host;
-        int fmr_page_shift, s, e, p;
+        int max_pages_per_fmr, fmr_page_shift, s, e, p;
 
         dev_attr = kmalloc(sizeof *dev_attr, GFP_KERNEL);
         if (!dev_attr)
@@ -2340,17 +2340,24 @@ static void srp_add_one(struct ib_device *device)
         if (IS_ERR(srp_dev->mr))
                 goto err_pd;
 
-        memset(&fmr_param, 0, sizeof fmr_param);
-        fmr_param.pool_size         = SRP_FMR_POOL_SIZE;
-        fmr_param.dirty_watermark   = SRP_FMR_DIRTY_SIZE;
-        fmr_param.cache             = 1;
-        fmr_param.max_pages_per_fmr = SRP_FMR_SIZE;
-        fmr_param.page_shift        = fmr_page_shift;
-        fmr_param.access            = (IB_ACCESS_LOCAL_WRITE |
-                                       IB_ACCESS_REMOTE_WRITE |
-                                       IB_ACCESS_REMOTE_READ);
-
-        srp_dev->fmr_pool = ib_create_fmr_pool(srp_dev->pd, &fmr_param);
+        for (max_pages_per_fmr = SRP_FMR_SIZE;
+                        max_pages_per_fmr >= SRP_FMR_MIN_SIZE;
+                        max_pages_per_fmr /= 2, srp_dev->fmr_max_size /= 2) {
+                memset(&fmr_param, 0, sizeof fmr_param);
+                fmr_param.pool_size         = SRP_FMR_POOL_SIZE;
+                fmr_param.dirty_watermark   = SRP_FMR_DIRTY_SIZE;
+                fmr_param.cache             = 1;
+                fmr_param.max_pages_per_fmr = max_pages_per_fmr;
+                fmr_param.page_shift        = fmr_page_shift;
+                fmr_param.access            = (IB_ACCESS_LOCAL_WRITE |
+                                               IB_ACCESS_REMOTE_WRITE |
+                                               IB_ACCESS_REMOTE_READ);
+
+                srp_dev->fmr_pool = ib_create_fmr_pool(srp_dev->pd, &fmr_param);
+                if (!IS_ERR(srp_dev->fmr_pool))
+                        break;
+        }
+
         if (IS_ERR(srp_dev->fmr_pool))
                 srp_dev->fmr_pool = NULL;
 
diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h
index cf696218eeeb..020caf0c3789 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -69,7 +69,8 @@ enum {
         SRP_TAG_NO_REQ          = ~0U,
         SRP_TAG_TSK_MGMT        = 1U << 31,
 
-        SRP_FMR_SIZE            = 256,
+        SRP_FMR_SIZE            = 512,
+        SRP_FMR_MIN_SIZE        = 128,
         SRP_FMR_POOL_SIZE       = 1024,
         SRP_FMR_DIRTY_SIZE      = SRP_FMR_POOL_SIZE / 4,