[PATCH] mlx5: avoid 64-bit division

Michal Kubecek
2019-05-20T11:19:07Z

Commit 25c13324d03d ("IB/mlx5: Add steering SW ICM device memory type")
breaks i386 build by introducing three 64-bit divisions. As the divisor
is MLX5_SW_ICM_BLOCK_SIZE() which is always a power of 2, we can replace
the division with bit operations.

Fixes: 25c13324d03d ("IB/mlx5: Add steering SW ICM device memory type")
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
---
drivers/infiniband/hw/mlx5/cmd.c | 9 +++++++--
drivers/infiniband/hw/mlx5/main.c | 2 +-
2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/hw/mlx5/cmd.c b/drivers/infiniband/hw/mlx5/cmd.c
index e3ec79b8f7f5..6c8645033102 100644
--- a/drivers/infiniband/hw/mlx5/cmd.c
+++ b/drivers/infiniband/hw/mlx5/cmd.c
@@ -190,12 +190,12 @@ int mlx5_cmd_alloc_sw_icm(struct mlx5_dm *dm, int type, u64 length,
u16 uid, phys_addr_t *addr, u32 *obj_id)
{
struct mlx5_core_dev *dev = dm->dev;
- u32 num_blocks = DIV_ROUND_UP(length, MLX5_SW_ICM_BLOCK_SIZE(dev));
u32 out[MLX5_ST_SZ_DW(general_obj_out_cmd_hdr)] = {};
u32 in[MLX5_ST_SZ_DW(create_sw_icm_in)] = {};
unsigned long *block_map;
u64 icm_start_addr;
u32 log_icm_size;
+ u32 num_blocks;
u32 max_blocks;
u64 block_idx;
void *sw_icm;
@@ -224,6 +224,8 @@ int mlx5_cmd_alloc_sw_icm(struct mlx5_dm *dm, int type, u64 length,
return -EINVAL;
}

+ num_blocks = (length + MLX5_SW_ICM_BLOCK_SIZE(dev) - 1) >>
+ MLX5_LOG_SW_ICM_BLOCK_SIZE(dev);
max_blocks = BIT(log_icm_size - MLX5_LOG_SW_ICM_BLOCK_SIZE(dev));
spin_lock(&dm->lock);
block_idx = bitmap_find_next_zero_area(block_map,
@@ -266,13 +268,16 @@ int mlx5_cmd_dealloc_sw_icm(struct mlx5_dm *dm, int type, u64 length,
u16 uid, phys_addr_t addr, u32 obj_id)
{
struct mlx5_core_dev *dev = dm->dev;
- u32 num_blocks = DIV_ROUND_UP(length, MLX5_SW_ICM_BLOCK_SIZE(dev));
u32 out[MLX5_ST_SZ_DW(general_obj_out_cmd_hdr)] = {};
u32 in[MLX5_ST_SZ_DW(general_obj_in_cmd_hdr)] = {};
unsigned long *block_map;
+ u32 num_blocks;
u64 start_idx;
int err;

+ num_blocks = (length + MLX5_SW_ICM_BLOCK_SIZE(dev) - 1) >>
+ MLX5_LOG_SW_ICM_BLOCK_SIZE(dev);
+
switch (type) {
case MLX5_IB_UAPI_DM_TYPE_STEERING_SW_ICM:
start_idx =
diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index abac70ad5c7c..340290b883fe 100644
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -2344,7 +2344,7 @@ static int handle_alloc_dm_sw_icm(struct ib_ucontext *ctx,
/* Allocation size must a multiple of the basic block size
* and a power of 2.
*/
- act_size = roundup(attr->length, MLX5_SW_ICM_BLOCK_SIZE(dm_db->dev));
+ act_size = round_up(attr->length, MLX5_SW_ICM_BLOCK_SIZE(dm_db->dev));
act_size = roundup_pow_of_two(act_size);

dm->size = act_size;
--
2.21.0