similar to: [PATCH 0/6] drm/nouveau: Support sync FDs and sync objects

From: Thierry Reding <treding at nvidia.com> This small series of patches implements support for waiting on and emitting fence FDs on kickoff. This enables explicit fencing and can be used for example to synchronize buffer accesses between the display engine and the GPU on Tegra. The first patch lays the groundwork by splitting up nouveau_fence_sync() to allow reuse. Patch 2 is where the

Hi guys, I'd like to start a new thread about explicit fence synchronization. This time with a Nouveau twist. :-) First, let me define what I understand by implicit/explicit sync: Implicit synchronization * Fences are attached to buffers * Kernel manages fences automatically based on buffer read/write access Explicit synchronization * Fences are passed around independently * Kernel takes

This series depends on the previously posted reservation api patches. 2 of them are not yet in for-next-fences branch of git://git.linaro.org/people/sumit.semwal/linux-3.x.git The missing patches are still in my vmwgfx_wip branch at git://people.freedesktop.org/~mlankhorst/linux All ttm drivers are converted to the fence api, fence_lock is removed and rcu is used in its place. qxl is the first

fence_is_signaled callback should support being run in atomic context, but not in irq context. Signed-off-by: Maarten Lankhorst <maarten.lankhorst at canonical.com> --- include/linux/fence.h | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) diff --git a/include/linux/fence.h b/include/linux/fence.h index d174585b874b..c1a4519ba2f5 100644 ---

This series applies on top of the driver-core-next branch of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git Before converting ttm to the new fence interface I had to fix some drivers to require a reservation before poking with fence_obj. After flipping the switch RCU becomes available instead, and the extra reservations can be dropped again. :-) I've done at least basic

nouveau_bo_wait will make the GPU channel wait for fence if possible, otherwise falling back to waiting with the CPU using ttm_bo_wait. The nouveau_fence_sync function currently returns -ENOSYS, and is the focus of the next patch. Signed-off-by: Luca Barbieri <luca at luca-barbieri.com> --- drivers/gpu/drm/nouveau/nouveau_bo.c | 68 ++++++++++++++++++++++++++++++-

Reduces object size ~4kb Joe Perches (2): drm/nouveau: Add new logging function nv_cli_printk drm/nouveau: Convert NV_PRINTK macros and uses to new nv_cli_<level> macros drivers/gpu/drm/nouveau/nouveau_abi16.c | 2 +- drivers/gpu/drm/nouveau/nouveau_chan.c | 12 +++---- drivers/gpu/drm/nouveau/nouveau_drm.c | 21 +++++++++++ drivers/gpu/drm/nouveau/nouveau_drv.h | 44

Changes in v2: - Addressed review comments nouveau_bo_wait will make the GPU channel wait for fence if possible, otherwise falling back to waiting with the CPU using ttm_bo_wait. The nouveau_fence_sync function currently returns -ENOSYS, and is the focus of the next patch. Signed-off-by: Luca Barbieri <luca at luca-barbieri.com> --- drivers/gpu/drm/nouveau/nouveau_bo.c | 68

- Depth and stencil buffers are supposed to be large enough in general. Signed-off-by: Maarten Maathuis <madman2003 at gmail.com> --- drivers/gpu/drm/nouveau/nouveau_bo.c | 9 ++++----- 1 files changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c index e342a41..9fc4bd6 100644 ---

nouveau_fence_emit() can fail before and after initializing the dma-fence and hence before and after initializing the dma-fence' kref. In order to avoid nouveau_fence_emit() potentially failing before dma-fence initialization pass the channel to nouveau_fence_new() already and perform the required check before even allocating the fence. While at it, restore the original behavior of

From: Maarten Lankhorst <maarten.lankhorst at canonical.com> Commit de7b7d59d54852c introduced tiled GART, but a linear copy is still performed. This may result in errors on eviction, fix it by checking tiling from memtype. Signed-off-by: Maarten Lankhorst <maarten.lankhorst at canonical.com> Cc: stable at vger.kernel.org #3.10+ --- drivers/gpu/drm/nouveau/nouveau_bo.c | 33

Commit "drm/nouveau: port all engines to new engine module format" changed IB size calculation to be less wasteful, but didn't take into account already existing off-by-one bugs :). So: - ib_max is the last entry, so we need to +1 when calculating number of free entries - nv50_dma_wait already does +1 (for FIRE_RING), so we don't need another +1 on nouveau_gem_ioctl_pushbuf

From: Thierry Reding <treding at nvidia.com> This set of patches adds support for fences to Tegra DRM and complements the fence FD support for Nouveau. Technically this isn't necessary for a fence-based synchronization loop with Nouveau because the KMS core takes care of all that, but engines behind host1x can use the IOCTL extensions provided here to emit fence FDs that in turn can be

From: Ben Skeggs <bskeggs at redhat.com> Signed-off-by: Ben Skeggs <bskeggs at redhat.com> --- drivers/gpu/drm/nouveau/nouveau_channel.c | 2 -- drivers/gpu/drm/nouveau/nouveau_drv.h | 1 - drivers/gpu/drm/nouveau/nouveau_fence.c | 28 ++++------------------------ drivers/gpu/drm/nouveau/nv04_graph.c | 1 - 4 files changed, 4 insertions(+), 28 deletions(-) diff

https://bugs.freedesktop.org/show_bug.cgi?id=47306 Bug #: 47306 Summary: segfault in nouveau_fence_update Classification: Unclassified Product: xorg Version: unspecified Platform: x86 (IA32) OS/Version: Linux (All) Status: NEW Severity: blocker Priority: medium Component: Driver/nouveau

Fence lock needs to be initialized before any call to nouveau_channel_put because it calls nouveau_channel_idle->nouveau_fence_update which uses fence lock. BUG: spinlock bad magic on CPU#0, test/24134 lock: ffff88019f90dba8, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 Pid: 24134, comm: test Not tainted 3.0.0-nv+ #800 Call Trace: spin_bug+0x9c/0xa3 do_raw_spin_lock+0x29/0x13c

From: Maarten Lankhorst <maarten.lankhorst at ubuntu.com> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at canonical.com> --- drivers/gpu/drm/nouveau/core/core/event.c | 4 drivers/gpu/drm/nouveau/nouveau_bo.c | 6 drivers/gpu/drm/nouveau/nouveau_display.c | 4 drivers/gpu/drm/nouveau/nouveau_fence.c | 434 ++++++++++++++++++++---------

From: Dave Airlie <airlied at redhat.com> fences are signalled on nvidia hw using non-stall interrupts. non-stall interrupts are not latched from my reading. When nouveau emits a fence, it requests a NON_STALL signalling, but it only calls the interface to allow the non-stall irq to happen after it has already emitted the fence. A recent change eacabb546271 ("nouveau: push event

On Tue, Jan 23, 2024 at 05:25:38PM +1000, Dave Airlie wrote: > From: Dave Airlie <airlied at redhat.com> > > fences are signalled on nvidia hw using non-stall interrupts. > > non-stall interrupts are not latched from my reading. > > When nouveau emits a fence, it requests a NON_STALL signalling, > but it only calls the interface to allow the non-stall irq to happen

Using the kernel global workqueue to signal fences can lead to unexpected deadlocks. Some other work (e.g. from a different driver) could directly or indirectly depend on this fence to be signaled. However, if the WQ_MAX_ACTIVE limit is reached by waiters, this can prevent the work signaling the fence from running. While this seems fairly unlikely, it's potentially exploitable. Fixes: