net/mlx5: fix doorbell bitmap management offsets

The doorbell record is organized with page and bitmap. When some new
doorbell needs to be associated with a queue, the bit will be set
in the bitmap to indicate the corresponding doorbell occupied. A
counter is used to record the number of doorbell occupied to speed
up the searching.
If the number reaches the maximal value of a pre-defined number of a
page, a new page will be allocated. If not, then the bitmap will be
checked to find a free one.
The LSHIFT and OR (AND NOT) operations are used to update the bitmap
of a page. But 1 will be treated as a signed integer when compiling.
When the shift number is 31, the shifted value will be considered as
negative. Then a wrong extension will be done when setting it to a
64-bits variable. All the upper 32-bits will be set to 1 by such
extension.
Then a wrong offset value will be calculated because of this. The
next 64 bits will be also treated as the bitmap and get corrupted
through the bit set operation.
The immediate value 1 needs to be used as 64 bits width explicitly.

Fixes: 21cae8580fd0 ("net/mlx5: allocate door-bells via DevX")
Cc: stable@dpdk.org
Signed-off-by: Bing Zhao <bingz@mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
Acked-by: Matan Azrad <matan@mellanox.com>

diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c
index 1445809..ab4adec 100644 (file)
--- a/drivers/net/mlx5/mlx5.c
+++ b/drivers/net/mlx5/mlx5.c
@@ -2174,7 +2174,7 @@ mlx5_get_dbr(struct rte_eth_dev *dev, struct mlx5_devx_dbr_page **dbr_page)
        /* Find the first clear bit. */
        MLX5_ASSERT(i < MLX5_DBR_BITMAP_SIZE);
        j = rte_bsf64(~page->dbr_bitmap[i]);
-       page->dbr_bitmap[i] |= (1 << j);
+       page->dbr_bitmap[i] |= (UINT64_C(1) << j);
        page->dbr_count++;
        *dbr_page = page;
        return (((i * 64) + j) * sizeof(uint64_t));
@@ -2219,7 +2219,7 @@ mlx5_release_dbr(struct rte_eth_dev *dev, uint32_t umem_id, uint64_t offset)
                int i = offset / 64;
                int j = offset % 64;
 
-               page->dbr_bitmap[i] &= ~(1 << j);
+               page->dbr_bitmap[i] &= ~(UINT64_C(1) << j);
        }
        return ret;
 }