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>

diff --git a/drivers/infiniband/core/fmr_pool.c b/drivers/infiniband/core/fmr_pool.c
index 838bf54..615fe9c 100644 (file)
--- 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);