IB/fmr: Use device's max_map_map_per_fmr attribute in FMR pool.

When creating a FMR pool, query the IB device and use the returned
max_map_map_per_fmr attribute as for the max number of FMR remaps. If
the device does not suport querying this attribute, use the original
IB_FMR_MAX_REMAPS (32) default.

Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 27 insertions, 3 deletions

diff --git a/drivers/infiniband/core/fmr_pool.c b/drivers/infiniband/core/fmr_pool.c
index 838bf54458d2..615fe9cc6c56 100644
--- a/drivers/infiniband/core/fmr_pool.c
+++ b/drivers/infiniband/core/fmr_pool.c
@@ -54,7 +54,7 @@ enum {
 /*
  * If an FMR is not in use, then the list member will point to either
  * its pool's free_list (if the FMR can be mapped again; that is,
- * remap_count < IB_FMR_MAX_REMAPS) or its pool's dirty_list (if the
+ * remap_count < pool->max_remaps) or its pool's dirty_list (if the
  * FMR needs to be unmapped before being remapped).  In either of
  * these cases it is a bug if the ref_count is not 0.  In other words,
  * if ref_count is > 0, then the list member must not be linked into
@@ -84,6 +84,7 @@ struct ib_fmr_pool {
 
         int                       pool_size;
         int                       max_pages;
+        int                       max_remaps;
         int                       dirty_watermark;
         int                       dirty_len;
         struct list_head          free_list;
@@ -214,8 +215,10 @@ struct ib_fmr_pool *ib_create_fmr_pool(struct ib_pd             *pd,
 {
         struct ib_device   *device;
         struct ib_fmr_pool *pool;
+        struct ib_device_attr *attr;
         int i;
         int ret;
+        int max_remaps;
 
         if (!params)
                 return ERR_PTR(-EINVAL);
@@ -228,6 +231,26 @@ struct ib_fmr_pool *ib_create_fmr_pool(struct ib_pd             *pd,
                 return ERR_PTR(-ENOSYS);
         }
 
+        attr = kmalloc(sizeof *attr, GFP_KERNEL);
+        if (!attr) {
+                printk(KERN_WARNING "couldn't allocate device attr struct");
+                return ERR_PTR(-ENOMEM);
+        }
+
+        ret = ib_query_device(device, attr);
+        if (ret) {
+                printk(KERN_WARNING "couldn't query device");
+                kfree(attr);
+                return ERR_PTR(ret);
+        }
+
+        if (!attr->max_map_per_fmr)
+                max_remaps = IB_FMR_MAX_REMAPS;
+        else
+                max_remaps = attr->max_map_per_fmr;
+
+        kfree(attr);
+
         pool = kmalloc(sizeof *pool, GFP_KERNEL);
         if (!pool) {
                 printk(KERN_WARNING "couldn't allocate pool struct");
@@ -258,6 +281,7 @@ struct ib_fmr_pool *ib_create_fmr_pool(struct ib_pd             *pd,
 
         pool->pool_size       = 0;
         pool->max_pages       = params->max_pages_per_fmr;
+        pool->max_remaps      = max_remaps;
         pool->dirty_watermark = params->dirty_watermark;
         pool->dirty_len       = 0;
         spin_lock_init(&pool->pool_lock);
@@ -279,7 +303,7 @@ struct ib_fmr_pool *ib_create_fmr_pool(struct ib_pd             *pd,
                 struct ib_pool_fmr *fmr;
                 struct ib_fmr_attr attr = {
                         .max_pages  = params->max_pages_per_fmr,
-                        .max_maps   = IB_FMR_MAX_REMAPS,
+                        .max_maps   = pool->max_remaps,
                         .page_shift = params->page_shift
                 };
 
@@ -489,7 +513,7 @@ int ib_fmr_pool_unmap(struct ib_pool_fmr *fmr)
 
         --fmr->ref_count;
         if (!fmr->ref_count) {
-                if (fmr->remap_count < IB_FMR_MAX_REMAPS) {
+                if (fmr->remap_count < pool->max_remaps) {
                         list_add_tail(&fmr->list, &pool->free_list);
                 } else {
                         list_add_tail(&fmr->list, &pool->dirty_list);