mlx4_core: Allow large mlx4_buddy bitmaps

mlx4_buddy_init uses kmalloc() to allocate bitmaps, which fails when
the required size is beyond the max supported value (or when memory is
too fragmented to handle a huge allocation).  Extend this to use use
vmalloc() if kmalloc() fails, and take that into account when freeing
the bitmaps as well.

This fixes a driver load failure when log num mtt is 26 or higher, and
is a step in the direction of allowing to register huge amounts of
memory on large memory systems.

Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 14 insertions, 4 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/mr.c b/drivers/net/ethernet/mellanox/mlx4/mr.c
index af55b7ce5341..d6a3a392a377 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mr.c
+++ b/drivers/net/ethernet/mellanox/mlx4/mr.c
@@ -37,6 +37,7 @@
 #include <linux/export.h>
 #include <linux/slab.h>
 #include <linux/kernel.h>
+#include <linux/vmalloc.h>
 
 #include <linux/mlx4/cmd.h>
 
@@ -130,8 +131,11 @@ static int mlx4_buddy_init(struct mlx4_buddy *buddy, int max_order)
         for (i = 0; i <= buddy->max_order; ++i) {
                 s = BITS_TO_LONGS(1 << (buddy->max_order - i));
                 buddy->bits[i] = kmalloc(s * sizeof (long), GFP_KERNEL);
-                if (!buddy->bits[i])
-                        goto err_out_free;
+                if (!buddy->bits[i]) {
+                        buddy->bits[i] = vmalloc(s * sizeof(long));
+                        if (!buddy->bits[i])
+                                goto err_out_free;
+                }
                 bitmap_zero(buddy->bits[i], 1 << (buddy->max_order - i));
         }
 
@@ -142,7 +146,10 @@ static int mlx4_buddy_init(struct mlx4_buddy *buddy, int max_order)
 
 err_out_free:
         for (i = 0; i <= buddy->max_order; ++i)
-                kfree(buddy->bits[i]);
+                if (buddy->bits[i] && is_vmalloc_addr(buddy->bits[i]))
+                        vfree(buddy->bits[i]);
+                else
+                        kfree(buddy->bits[i]);
 
 err_out:
         kfree(buddy->bits);
@@ -156,7 +163,10 @@ static void mlx4_buddy_cleanup(struct mlx4_buddy *buddy)
         int i;
 
         for (i = 0; i <= buddy->max_order; ++i)
-                kfree(buddy->bits[i]);
+                if (is_vmalloc_addr(buddy->bits[i]))
+                        vfree(buddy->bits[i]);
+                else
+                        kfree(buddy->bits[i]);
 
         kfree(buddy->bits);
         kfree(buddy->num_free);