| Commit message (Collapse) | Author | Age |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Revamp the support the nvgpu driver has for semaphores.
The original problem with nvgpu's semaphore support is that it
required a SW based wait for every semaphore release. This was
because for every fence that gk20a_channel_semaphore_wait_fd()
waited on a new semaphore was created. This semaphore would then
get released by SW when the fence signaled. This meant that for
every release there was necessarily a sync_fence_wait_async() call
which could block. The latency of this SW wait was enough to cause
massive degredation in performance.
To fix this a fast path was implemented. When a fence is passed to
gk20a_channel_semaphore_wait_fd() that is backed by a GPU semaphore
a semaphore acquire is directly used to block the GPU. No longer is
a sync_fence_wait_async() performed nor is there an extra semaphore
created.
To implement this fast path the semaphore memory had to be shared
between channels. Previously since a new semaphore was created
every time through gk20a_channel_semaphore_wait_fd() what address
space a semaphore was mapped into was irrelevant. However, when
using the fast path a sempahore may be released on one address
space but acquired in another.
Sharing the semaphore memory was done by making a fixed GPU mapping
in all channels. This mapping points to the semaphore memory (the
so called semaphore sea). This global fixed mapping is read-only to
make sure no semaphores can be incremented (i.e released) by a
malicious channel. Each channel then gets a RW mapping of it's own
semaphore. This way a channel may only acquire other channel's
semaphores but may both acquire and release its own semaphore.
The gk20a fence code was updated to allow introspection of the GPU
backed fences. This allows detection of when the fast path can be
taken. If the fast path cannot be used (for example when a fence is
sync-pt backed) the original slow path is still present. This gets
used when the GPU needs to wait on an event from something which
only understands how to use sync-pts.
Bug 1732449
JIRA DNVGPU-12
Change-Id: Ic0fea74994da5819a771deac726bb0d47a33c2de
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: http://git-master/r/1133792
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Replace manual buffer allocation and cpu_va pointer accesses with
gk20a_gmmu_{alloc,free}() and gk20a_mem_{rd,wr}() using a struct
mem_desc in gk20a_semaphore_pool, for buffer aperture flexibility.
JIRA DNVGPU-23
Change-Id: I394c38f407a9da02480bfd35062a892eec242ea3
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: http://git-master/r/1146684
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
To help remove the nvhost dependency from nvgpu, rename ioctl defines
and structures used by nvgpu such that nvhost is replaced by nvgpu.
Duplicate some structures as needed.
Update header guards and such accordingly.
Change-Id: Ifc3a867713072bae70256502735583ab38381877
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: http://git-master/r/542620
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>
|
|
Add semaphore_gk20a.c/h that implement a new semaphore management API
for the gk20a driver. The API introduces two entities, 'semaphore pools'
and 'semaphores'.
Semaphore pools are memory areas dedicated for hosting one or more
semaphores. Typically, one pool equals one 4K page. A semaphore pool
is always mapped to the kernel memory, and it can be mapped and
unmapped to gpu address spaces using gk20a_semaphore_pool_map/unmap.
Semaphores are backed by 16 bytes of memory allocated from a semaphore
pool. The value of a semaphore can be 0=acuired or 1=released. When
allocated, the semaphores are initialized to the acquired state. They
can be released, or their releasing can be waited for by the CPU or GPU.
Semaphores are intended to be used only once, and after they are
released they should be freed so that the slot within the semaphore
pool can be reused. However GPU jobs must take references to the
semaphores that they use (similarly as they take references on memory
buffers that they use) so that the semaphore backing memory is not
reused too soon.
Bug 1450122
Bug 1445450
Change-Id: I3fd35f34ca55035decc3e06a9c0ede20c1d48db9
Signed-off-by: Lauri Peltonen <lpeltonen@nvidia.com>
Reviewed-on: http://git-master/r/374842
Reviewed-by: Arto Merilainen <amerilainen@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
|