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.c | |
parent | b00a92c8f2cae4ea8c84ddae9b9ba5daeb9f327f (diff) | |
download | linux-stable-5f9794dc94f59ad1eb821724a8ae1f8e803ea188.tar.gz linux-stable-5f9794dc94f59ad1eb821724a8ae1f8e803ea188.tar.bz2 linux-stable-5f9794dc94f59ad1eb821724a8ae1f8e803ea188.zip |
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.c')
-rw-r--r-- | drivers/infiniband/core/rdma_core.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/infiniband/core/rdma_core.c b/drivers/infiniband/core/rdma_core.c index c4118bcd5103..06d31fe56677 100644 --- a/drivers/infiniband/core/rdma_core.c +++ b/drivers/infiniband/core/rdma_core.c @@ -842,8 +842,10 @@ static void ufile_destroy_ucontext(struct ib_uverbs_file *ufile, struct ib_ucontext *ucontext = ufile->ucontext; int ret; - if (reason == RDMA_REMOVE_DRIVER_REMOVE) + if (reason == RDMA_REMOVE_DRIVER_REMOVE) { + uverbs_user_mmap_disassociate(ufile); ufile_disassociate_ucontext(ucontext); + } put_pid(ucontext->tgid); ib_rdmacg_uncharge(&ucontext->cg_obj, ucontext->device, |