dma-buf: Enable signaling on fence for selftests

Here's enabling software signaling on fence for selftest.

Signed-off-by: Arvind Yadav <Arvind.Yadav@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220914164321.2156-4-Arvind.Yadav@amd.com
Signed-off-by: Christian König <christian.koenig@amd.com>

dma-buf: drop seq count based update

This should be possible now since we don't have the distinction
between exclusive and shared fences any more.

The only possible pitfall is that a dma_fence would be reused during the
RCU grace period, but even that could be handled with a single extra check.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220407085946.744568-15-christian.koenig@amd.com

dma-buf: add DMA_RESV_USAGE_BOOKKEEP v3

Add an usage for submissions independent of implicit sync but still
interesting for memory management.

v2: cleanup the kerneldoc a bit
v3: separate amdgpu changes from this

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220407085946.744568-10-christian.koenig@amd.com

dma-buf: add DMA_RESV_USAGE_KERNEL v3

Add an usage for kernel submissions. Waiting for those are mandatory for
dynamic DMA-bufs.

As a precaution this patch also changes all occurrences where fences are
added as part of memory management in TTM, VMWGFX and i915 to use the
new value because it now becomes possible for drivers to ignore fences
with the WRITE usage.

v2: use "must" in documentation, fix whitespaces
v3: separate out some driver changes and better document why some
changes should still be part of this patch.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220407085946.744568-5-christian.koenig@amd.com

dma-buf: specify usage while adding fences to dma_resv obj v7

Instead of distingting between shared and exclusive fences specify
the fence usage while adding fences.

Rework all drivers to use this interface instead and deprecate the old one.

v2: some kerneldoc comments suggested by Daniel
v3: fix a missing case in radeon
v4: rebase on nouveau changes, fix lockdep and temporary disable warning
v5: more documentation updates
v6: separate internal dma_resv changes from this patch, avoids to
disable warning temporary, rebase on upstream changes
v7: fix missed case in lima driver, minimize changes to i915_gem_busy_ioctl

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220407085946.744568-3-christian.koenig@amd.com

dma-buf: add enum dma_resv_usage v4

This change adds the dma_resv_usage enum and allows us to specify why a
dma_resv object is queried for its containing fences.

Additional to that a dma_resv_usage_rw() helper function is added to aid
retrieving the fences for a read or write userspace submission.

This is then deployed to the different query functions of the dma_resv
object and all of their users. When the write paratermer was previously
true we now use DMA_RESV_USAGE_WRITE and DMA_RESV_USAGE_READ otherwise.

v2: add KERNEL/OTHER in separate patch
v3: some kerneldoc suggestions by Daniel
v4: some more kerneldoc suggestions by Daniel, fix missing cases lost in
the rebase pointed out by Bas.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220407085946.744568-2-christian.koenig@amd.com

dma-buf/drivers: make reserving a shared slot mandatory v4

Audit all the users of dma_resv_add_excl_fence() and make sure they
reserve a shared slot also when only trying to add an exclusive fence.

This is the next step towards handling the exclusive fence like a
shared one.

v2: fix missed case in amdgpu
v3: and two more radeon, rename function
v4: add one more case to TTM, fix i915 after rebase

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220406075132.3263-2-christian.koenig@amd.com

dma-buf: drop excl_fence parameter from dma_resv_get_fences

Returning the exclusive fence separately is no longer used.

Instead add a write parameter to indicate the use case.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20211207123411.167006-4-christian.koenig@amd.com

dma-buf: st: fix error handling in test_get_fences()

The new driver incorrectly unwinds after errors, as clang points out:

drivers/dma-buf/st-dma-resv.c:295:7: error: variable 'i' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
if (r) {
^
drivers/dma-buf/st-dma-resv.c:336:9: note: uninitialized use occurs here
while (i--)
^
drivers/dma-buf/st-dma-resv.c:295:3: note: remove the 'if' if its condition is always false
if (r) {
^~~~~~~~
drivers/dma-buf/st-dma-resv.c:288:6: error: variable 'i' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
if (r) {
^
drivers/dma-buf/st-dma-resv.c:336:9: note: uninitialized use occurs here
while (i--)
^
drivers/dma-buf/st-dma-resv.c:288:2: note: remove the 'if' if its condition is always false
if (r) {
^~~~~~~~
drivers/dma-buf/st-dma-resv.c:280:10: note: initialize the variable 'i' to silence this warning
int r, i;
^
= 0

Skip cleaning up the bits that have not been allocated at this point.

Fixes: 1d51775cd3f5 ("dma-buf: add dma_resv selftest v4")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20211026083448.3471055-1-arnd@kernel.org
Signed-off-by: Christian König <christian.koenig@amd.com>

dma-buf: add dma_resv selftest v4

Just exercising a very minor subset of the functionality, but already
proven useful.

v2: add missing locking
v3: some more cleanup and consolidation, add unlocked test as well
v4: add a dma_resv_get_fences selftest

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> (v3)
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v3)
Link: https://patchwork.freedesktop.org/patch/msgid/20211005113742.1101-4-christian.koenig@amd.com