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| author |   Jason Gunthorpe <jgg@mellanox.com> | 2019-10-09 13:09:34 -0300 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2019-10-28 16:41:14 -0300 |
| commit | 09689703d29a3b75c510c198c3aca85d7d8b50c7 (patch) | |
| tree | 378ec2883f70d270bbc1dc2068ede78979163c39 /drivers/infiniband/hw/mlx5/mlx5_ib.h | |
| parent | RDMA/mlx5: Do not store implicit children in the odp_mkeys xarray (diff) | |
| download | linux-dev-09689703d29a3b75c510c198c3aca85d7d8b50c7.tar.xz linux-dev-09689703d29a3b75c510c198c3aca85d7d8b50c7.zip | |
RDMA/mlx5: Do not race with mlx5_ib_invalidate_range during create and destroy
For creation, as soon as the umem_odp is created the notifier can be
called, however the underlying MR may not have been setup yet. This would
cause problems if mlx5_ib_invalidate_range() runs. There is some
confusing/ulocked/racy code that might by trying to solve this, but
without locks it isn't going to work right.
Instead trivially solve the problem by short-circuiting the invalidation
if there are not yet any DMA mapped pages. By definition there is nothing
to invalidate in this case.
The create code will have the umem fully setup before anything is DMA
mapped, and npages is fully locked by the umem_mutex.
For destroy, invalidate the entire MR at the HW to stop DMA then DMA unmap
the pages before destroying the MR. This drives npages to zero and
prevents similar racing with invalidate while the MR is undergoing
destruction.
Arguably it would be better if the umem was created after the MR and
destroyed before, but that would require a big rework of the MR code.
Fixes: 6aec21f6a832 ("IB/mlx5: Page faults handling infrastructure")
Link: https://lore.kernel.org/r/20191009160934.3143-15-jgg@ziepe.ca
Reviewed-by: Artemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'drivers/infiniband/hw/mlx5/mlx5_ib.h')
| -rw-r--r-- | drivers/infiniband/hw/mlx5/mlx5_ib.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h index b8c958f62628..f61d4005c6c3 100644 --- a/drivers/infiniband/hw/mlx5/mlx5_ib.h +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h @@ -1171,6 +1171,7 @@ struct mlx5_ib_mr *mlx5_ib_alloc_implicit_mr(struct mlx5_ib_pd *pd, struct ib_udata *udata, int access_flags); void mlx5_ib_free_implicit_mr(struct mlx5_ib_mr *mr); +void mlx5_ib_fence_odp_mr(struct mlx5_ib_mr *mr); int mlx5_ib_rereg_user_mr(struct ib_mr *ib_mr, int flags, u64 start, u64 length, u64 virt_addr, int access_flags, struct ib_pd *pd, struct ib_udata *udata); @@ -1232,6 +1233,8 @@ int mlx5_mr_cache_cleanup(struct mlx5_ib_dev *dev); struct mlx5_ib_mr *mlx5_mr_cache_alloc(struct mlx5_ib_dev *dev, int entry); void mlx5_mr_cache_free(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr); +int mlx5_mr_cache_invalidate(struct mlx5_ib_mr *mr); + int mlx5_ib_check_mr_status(struct ib_mr *ibmr, u32 check_mask, struct ib_mr_status *mr_status); struct ib_wq *mlx5_ib_create_wq(struct ib_pd *pd, |