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net/mlx4_core: Cleanup FMR unmapping flow

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Remove redundant and not essential operations in fmr unmap/free.
According to device spec, in FMR unmap it is sufficient to set
ownership bit to SW. This allows remapping afterwards.

Fixes: 8ad11fb6b073 ("IB/mlx4: Implement FMRs")
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tariq Toukan 2017-12-28 16:26:10 +02:00 committed by David S. Miller
parent dc484851ed
commit fd4a3e2828
1 changed files with 22 additions and 20 deletions
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42
drivers/net/ethernet/mellanox/mlx4/mr.c
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@ -1103,30 +1103,16 @@ EXPORT_SYMBOL_GPL(mlx4_fmr_enable);
void mlx4_fmr_unmap(struct mlx4_dev *dev, struct mlx4_fmr *fmr,
u32 *lkey, u32 *rkey)
{
struct mlx4_cmd_mailbox *mailbox;
int err;
if (!fmr->maps)
return;
/* To unmap: it is sufficient to take back ownership from HW */
*(u8 *)fmr->mpt = MLX4_MPT_STATUS_SW;
/* Make sure MPT status is visible */
wmb();
fmr->maps = 0;
mailbox = mlx4_alloc_cmd_mailbox(dev);
if (IS_ERR(mailbox)) {
err = PTR_ERR(mailbox);
pr_warn("mlx4_ib: mlx4_alloc_cmd_mailbox failed (%d)\n", err);
return;
}
err = mlx4_HW2SW_MPT(dev, NULL,
key_to_hw_index(fmr->mr.key) &
(dev->caps.num_mpts - 1));
mlx4_free_cmd_mailbox(dev, mailbox);
if (err) {
pr_warn("mlx4_ib: mlx4_HW2SW_MPT failed (%d)\n", err);
return;
}
fmr->mr.enabled = MLX4_MPT_EN_SW;
}
EXPORT_SYMBOL_GPL(mlx4_fmr_unmap);
@ -1136,6 +1122,22 @@ int mlx4_fmr_free(struct mlx4_dev *dev, struct mlx4_fmr *fmr)
if (fmr->maps)
return -EBUSY;
if (fmr->mr.enabled == MLX4_MPT_EN_HW) {
/* In case of FMR was enabled and unmapped
* make sure to give ownership of MPT back to HW
* so HW2SW_MPT command will success.
*/
*(u8 *)fmr->mpt = MLX4_MPT_STATUS_SW;
/* Make sure MPT status is visible before changing MPT fields */
wmb();
fmr->mpt->length = 0;
fmr->mpt->start = 0;
/* Make sure MPT data is visible after changing MPT status */
wmb();
*(u8 *)fmr->mpt = MLX4_MPT_STATUS_HW;
/* make sure MPT status is visible */
wmb();
}
ret = mlx4_mr_free(dev, &fmr->mr);
if (ret)