diff options
| author | Jason Gunthorpe <jgg@mellanox.com> | 2018-09-16 20:43:08 +0300 |
|---|---|---|
| committer | Doug Ledford <dledford@redhat.com> | 2018-09-20 16:19:30 -0400 |
| commit | 5f9794dc94f59ad1eb821724a8ae1f8e803ea188 (patch) | |
| tree | 99a96e10ceaf382b3684720b6c853ccaa2fa2e52 /drivers/infiniband/core/rdma_core.h | |
| parent | b00a92c8f2cae4ea8c84ddae9b9ba5daeb9f327f (diff) | |
RDMA/ucontext: Add a core API for mmaping driver IO memory
To support disassociation and PCI hot unplug, we have to track all the
VMAs that refer to the device IO memory. When disassociation occurs the
VMAs have to be revised to point to the zero page, not the IO memory, to
allow the physical HW to be unplugged.
The three drivers supporting this implemented three different versions
of this algorithm, all leaving something to be desired. This new common
implementation has a few differences from the driver versions:
- Track all VMAs, including splitting/truncating/etc. Tie the lifetime of
the private data allocation to the lifetime of the vma. This avoids any
tricks with setting vm_ops which Linus didn't like. (see link)
- Support multiple mms, and support properly tracking mmaps triggered by
processes other than the one first opening the uverbs fd. This makes
fork behavior of disassociation enabled drivers the same as fork support
in normal drivers.
- Don't use crazy get_task stuff.
- Simplify the approach for to racing between vm_ops close and
disassociation, fixing the related bugs most of the driver
implementations had. Since we are in core code the tracking list can be
placed in struct ib_uverbs_ufile, which has a lifetime strictly longer
than any VMAs created by mmap on the uverbs FD.
Link: https://www.spinics.net/lists/stable/msg248747.html
Link: https://lkml.kernel.org/r/CA+55aFxJTV_g46AQPoPXen-UPiqR1HGMZictt7VpC-SMFbm3Cw@mail.gmail.com
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers/infiniband/core/rdma_core.h')
| -rw-r--r-- | drivers/infiniband/core/rdma_core.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/infiniband/core/rdma_core.h b/drivers/infiniband/core/rdma_core.h index f962f2a593ba..4886d2bba7c7 100644 --- a/drivers/infiniband/core/rdma_core.h +++ b/drivers/infiniband/core/rdma_core.h @@ -160,5 +160,6 @@ void uverbs_disassociate_api(struct uverbs_api *uapi); void uverbs_destroy_api(struct uverbs_api *uapi); void uapi_compute_bundle_size(struct uverbs_api_ioctl_method *method_elm, unsigned int num_attrs); +void uverbs_user_mmap_disassociate(struct ib_uverbs_file *ufile); #endif /* RDMA_CORE_H */ |