Linaro-mm-sig October 2020

linaro-mm-sig@lists.linaro.org

13 participants
29 discussions

[PATCH 20/65] drm/scheduler: use dma-fence annotations in tdr work

by Daniel Vetter

In the face of unpriviledged userspace being able to submit bogus gpu workloads the kernel needs gpu timeout and reset (tdr) to guarantee that dma_fences actually complete. Annotate this worker to make sure we don't have any accidental locking inversions or other problems lurking. Originally this was part of the overall scheduler annotation patch. But amdgpu has some glorious inversions here: - grabs console_lock - does a full modeset, which grabs all kinds of locks (drm_modeset_lock, dma_resv_lock) which can deadlock with dma_fence_wait held inside them. - almost minor at that point, but the modeset code also allocates memory These all look like they'll be very hard to fix properly, the hardware seems to require a full display reset with any gpu recovery. Hence split out as a seperate patch. Since amdgpu isn't the only hardware driver that needs to reset the display (at least gen2/3 on intel have the same problem) we need a generic solution for this. There's two tricks we could still from drm/i915 and lift to dma-fence: - The big whack, aka force-complete all fences. i915 does this for all pending jobs if the reset is somehow stuck. Trouble is we'd need to do this for all fences in the entire system, and just the book-keeping for that will be fun. Plus lots of drivers use fences for all kinds of internal stuff like memory management, so unconditionally resetting all of them doesn't work. I'm also hoping that with these fence annotations we could enlist lockdep in finding the last offenders causing deadlocks, and we could remove this get-out-of-jail trick. - The more feasible approach (across drivers at least as part of the dma_fence contract) is what drm/i915 does for gen2/3: When we need to reset the display we wake up all dma_fence_wait_interruptible calls, or well at least the equivalent of those in i915 internally. Relying on ioctl restart we force all other threads to release their locks, which means the tdr thread is guaranteed to be able to get them. I think we could implement this at the dma_fence level, including proper lockdep annotations. dma_fence_begin_tdr(): - must be nested within a dma_fence_begin/end_signalling section - will wake up all interruptible (but not the non-interruptible) dma_fence_wait() calls and force them to complete with a -ERESTARTSYS errno code. All new interrupitble calls to dma_fence_wait() will immeidately fail with the same error code. dma_fence_end_trdr(): - this will convert dma_fence_wait() calls back to normal. Of course interrupting dma_fence_wait is only ok if the caller specified that, which means we need to split the annotations into interruptible and non-interruptible version. If we then make sure that we only use interruptible dma_fence_wait() calls while holding drm_modeset_lock we can grab them in tdr code, and allow display resets. Doing the same for dma_resv_lock might be a lot harder, so buffer updates must be avoided. What's worse, we're not going to be able to make the dma_fence_wait calls in mmu-notifiers interruptible, that doesn't work. So allocating memory still wont' be allowed, even in tdr sections. Plus obviously we can use this trick only in tdr, it is rather intrusive. Cc: linux-media(a)vger.kernel.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: linux-rdma(a)vger.kernel.org Cc: amd-gfx(a)lists.freedesktop.org Cc: intel-gfx(a)lists.freedesktop.org Cc: Chris Wilson <chris(a)chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Christian König <christian.koenig(a)amd.com> Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> --- drivers/gpu/drm/scheduler/sched_main.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index f69abc4e70d3..ae0d5ceca49a 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -281,9 +281,12 @@ static void drm_sched_job_timedout(struct work_struct *work) { struct drm_gpu_scheduler *sched; struct drm_sched_job *job; + bool fence_cookie; sched = container_of(work, struct drm_gpu_scheduler, work_tdr.work); + fence_cookie = dma_fence_begin_signalling(); + /* Protects against concurrent deletion in drm_sched_get_cleanup_job */ spin_lock(&sched->job_list_lock); job = list_first_entry_or_null(&sched->ring_mirror_list, @@ -315,6 +318,8 @@ static void drm_sched_job_timedout(struct work_struct *work) spin_lock(&sched->job_list_lock); drm_sched_start_timeout(sched); spin_unlock(&sched->job_list_lock); + + dma_fence_end_signalling(fence_cookie); } /** -- 2.28.0

4 years, 2 months

[PATCH 19/65] drm/amdgpu: s/GFP_KERNEL/GFP_ATOMIC in scheduler code

by Daniel Vetter

My dma-fence lockdep annotations caught an inversion because we allocate memory where we really shouldn't: kmem_cache_alloc+0x2b/0x6d0 amdgpu_fence_emit+0x30/0x330 [amdgpu] amdgpu_ib_schedule+0x306/0x550 [amdgpu] amdgpu_job_run+0x10f/0x260 [amdgpu] drm_sched_main+0x1b9/0x490 [gpu_sched] kthread+0x12e/0x150 Trouble right now is that lockdep only validates against GFP_FS, which would be good enough for shrinkers. But for mmu_notifiers we actually need !GFP_ATOMIC, since they can be called from any page laundering, even if GFP_NOFS or GFP_NOIO are set. I guess we should improve the lockdep annotations for fs_reclaim_acquire/release. Ofc real fix is to properly preallocate this fence and stuff it into the amdgpu job structure. But GFP_ATOMIC gets the lockdep splat out of the way. v2: Two more allocations in scheduler paths. Frist one: __kmalloc+0x58/0x720 amdgpu_vmid_grab+0x100/0xca0 [amdgpu] amdgpu_job_dependency+0xf9/0x120 [amdgpu] drm_sched_entity_pop_job+0x3f/0x440 [gpu_sched] drm_sched_main+0xf9/0x490 [gpu_sched] Second one: kmem_cache_alloc+0x2b/0x6d0 amdgpu_sync_fence+0x7e/0x110 [amdgpu] amdgpu_vmid_grab+0x86b/0xca0 [amdgpu] amdgpu_job_dependency+0xf9/0x120 [amdgpu] drm_sched_entity_pop_job+0x3f/0x440 [gpu_sched] drm_sched_main+0xf9/0x490 [gpu_sched] Cc: linux-media(a)vger.kernel.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: linux-rdma(a)vger.kernel.org Cc: amd-gfx(a)lists.freedesktop.org Cc: intel-gfx(a)lists.freedesktop.org Cc: Chris Wilson <chris(a)chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Christian König <christian.koenig(a)amd.com> Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> --- drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c index fe2d495d08ab..09614b325b5f 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c @@ -143,7 +143,7 @@ int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence **f, uint32_t seq; int r; - fence = kmem_cache_alloc(amdgpu_fence_slab, GFP_KERNEL); + fence = kmem_cache_alloc(amdgpu_fence_slab, GFP_ATOMIC); if (fence == NULL) return -ENOMEM; diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c index 7521f4ab55de..2a4cde7cd746 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c @@ -208,7 +208,7 @@ static int amdgpu_vmid_grab_idle(struct amdgpu_vm *vm, if (ring->vmid_wait && !dma_fence_is_signaled(ring->vmid_wait)) return amdgpu_sync_fence(sync, ring->vmid_wait); - fences = kmalloc_array(sizeof(void *), id_mgr->num_ids, GFP_KERNEL); + fences = kmalloc_array(sizeof(void *), id_mgr->num_ids, GFP_ATOMIC); if (!fences) return -ENOMEM; diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c index 8ea6c49529e7..af22b526cec9 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c @@ -160,7 +160,7 @@ int amdgpu_sync_fence(struct amdgpu_sync *sync, struct dma_fence *f) if (amdgpu_sync_add_later(sync, f)) return 0; - e = kmem_cache_alloc(amdgpu_sync_slab, GFP_KERNEL); + e = kmem_cache_alloc(amdgpu_sync_slab, GFP_ATOMIC); if (!e) return -ENOMEM; -- 2.28.0

4 years, 2 months

[PATCH 18/65] drm/amdgpu: use dma-fence annotations in cs_submit()

by Daniel Vetter

This is a bit tricky, since ->notifier_lock is held while calling dma_fence_wait we must ensure that also the read side (i.e. dma_fence_begin_signalling) is on the same side. If we mix this up lockdep complaints, and that's again why we want to have these annotations. A nice side effect of this is that because of the fs_reclaim priming for dma_fence_enable lockdep now automatically checks for us that nothing in here allocates memory, without even running any userptr workloads. Cc: linux-media(a)vger.kernel.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: linux-rdma(a)vger.kernel.org Cc: amd-gfx(a)lists.freedesktop.org Cc: intel-gfx(a)lists.freedesktop.org Cc: Chris Wilson <chris(a)chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Christian König <christian.koenig(a)amd.com> Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> --- drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c index d50b63a93d37..3b3999225e31 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c @@ -1212,6 +1212,7 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p, struct amdgpu_job *job; uint64_t seq; int r; + bool fence_cookie; job = p->job; p->job = NULL; @@ -1226,6 +1227,8 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p, */ mutex_lock(&p->adev->notifier_lock); + fence_cookie = dma_fence_begin_signalling(); + /* If userptr are invalidated after amdgpu_cs_parser_bos(), return * -EAGAIN, drmIoctl in libdrm will restart the amdgpu_cs_ioctl. */ @@ -1262,12 +1265,14 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p, amdgpu_vm_move_to_lru_tail(p->adev, &fpriv->vm); ttm_eu_fence_buffer_objects(&p->ticket, &p->validated, p->fence); + dma_fence_end_signalling(fence_cookie); mutex_unlock(&p->adev->notifier_lock); return 0; error_abort: drm_sched_job_cleanup(&job->base); + dma_fence_end_signalling(fence_cookie); mutex_unlock(&p->adev->notifier_lock); error_unlock: -- 2.28.0

4 years, 2 months

[PATCH 17/65] drm/scheduler: use dma-fence annotations in main thread

by Daniel Vetter

If the scheduler rt thread gets stuck on a mutex that we're holding while waiting for gpu workloads to complete, we have a problem. Add dma-fence annotations so that lockdep can check this for us. I've tried to quite carefully review this, and I think it's at the right spot. But obviosly no expert on drm scheduler. Cc: linux-media(a)vger.kernel.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: linux-rdma(a)vger.kernel.org Cc: amd-gfx(a)lists.freedesktop.org Cc: intel-gfx(a)lists.freedesktop.org Cc: Chris Wilson <chris(a)chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Christian König <christian.koenig(a)amd.com> Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> --- drivers/gpu/drm/scheduler/sched_main.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index 9a0d77a68018..f69abc4e70d3 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -764,9 +764,12 @@ static int drm_sched_main(void *param) { struct drm_gpu_scheduler *sched = (struct drm_gpu_scheduler *)param; int r; + bool fence_cookie; sched_set_fifo_low(current); + fence_cookie = dma_fence_begin_signalling(); + while (!kthread_should_stop()) { struct drm_sched_entity *entity = NULL; struct drm_sched_fence *s_fence; @@ -824,6 +827,9 @@ static int drm_sched_main(void *param) wake_up(&sched->job_scheduled); } + + dma_fence_end_signalling(fence_cookie); + return 0; } -- 2.28.0

4 years, 2 months

[PATCH 08/65] drm/amdgpu: add dma-fence annotations to atomic commit path

by Daniel Vetter

I need a canary in a ttm-based atomic driver to make sure the dma_fence_begin/end_signalling annotations actually work. Cc: linux-media(a)vger.kernel.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: linux-rdma(a)vger.kernel.org Cc: amd-gfx(a)lists.freedesktop.org Cc: intel-gfx(a)lists.freedesktop.org Cc: Chris Wilson <chris(a)chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Christian König <christian.koenig(a)amd.com> Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index bb1bc7f5d149..b05fecf06f25 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -57,6 +57,7 @@ #include "ivsrcid/ivsrcid_vislands30.h" +#include <linux/module.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/version.h> @@ -7492,6 +7493,9 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state) struct dm_crtc_state *dm_old_crtc_state, *dm_new_crtc_state; int crtc_disable_count = 0; bool mode_set_reset_required = false; + bool fence_cookie; + + fence_cookie = dma_fence_begin_signalling(); drm_atomic_helper_update_legacy_modeset_state(dev, state); drm_atomic_helper_calc_timestamping_constants(state); @@ -7816,6 +7820,8 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state) /* Signal HW programming completion */ drm_atomic_helper_commit_hw_done(state); + dma_fence_end_signalling(fence_cookie); + if (wait_for_vblank) drm_atomic_helper_wait_for_flip_done(dev, state); -- 2.28.0

4 years, 2 months

[PATCH 07/65] drm/vblank: Annotate with dma-fence signalling section

by Daniel Vetter

This is rather overkill since currently all drivers call this from hardirq (or at least timers). But maybe in the future we're going to have thread irq handlers and what not, doesn't hurt to be prepared. Plus this is an easy start for sprinkling these fence annotations into shared code. Cc: linux-media(a)vger.kernel.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: linux-rdma(a)vger.kernel.org Cc: amd-gfx(a)lists.freedesktop.org Cc: intel-gfx(a)lists.freedesktop.org Cc: Chris Wilson <chris(a)chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Christian König <christian.koenig(a)amd.com> Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> --- drivers/gpu/drm/drm_vblank.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c index f135b79593dd..ba7e741764aa 100644 --- a/drivers/gpu/drm/drm_vblank.c +++ b/drivers/gpu/drm/drm_vblank.c @@ -24,6 +24,7 @@ * OTHER DEALINGS IN THE SOFTWARE. */ +#include <linux/dma-fence.h> #include <linux/export.h> #include <linux/kthread.h> #include <linux/moduleparam.h> @@ -1913,7 +1914,7 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe) { struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; unsigned long irqflags; - bool disable_irq; + bool disable_irq, fence_cookie; if (drm_WARN_ON_ONCE(dev, !drm_dev_has_vblank(dev))) return false; @@ -1921,6 +1922,8 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe) if (drm_WARN_ON(dev, pipe >= dev->num_crtcs)) return false; + fence_cookie = dma_fence_begin_signalling(); + spin_lock_irqsave(&dev->event_lock, irqflags); /* Need timestamp lock to prevent concurrent execution with @@ -1933,6 +1936,7 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe) if (!vblank->enabled) { spin_unlock(&dev->vblank_time_lock); spin_unlock_irqrestore(&dev->event_lock, irqflags); + dma_fence_end_signalling(fence_cookie); return false; } @@ -1959,6 +1963,8 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe) if (disable_irq) vblank_disable_fn(&vblank->disable_timer); + dma_fence_end_signalling(fence_cookie); + return true; } EXPORT_SYMBOL(drm_handle_vblank); -- 2.28.0

4 years, 2 months

[PATCH 06/65] drm/vkms: Annotate vblank timer

by Daniel Vetter

This is needed to signal the fences from page flips, annotate it accordingly. We need to annotate entire timer callback since if we get stuck anywhere in there, then the timer stops, and hence fences stop. Just annotating the top part that does the vblank handling isn't enough. Tested-by: Melissa Wen <melissa.srw(a)gmail.com> Reviewed-by: Rodrigo Siqueira <rodrigosiqueiramelo(a)gmail.com> Cc: linux-media(a)vger.kernel.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: linux-rdma(a)vger.kernel.org Cc: amd-gfx(a)lists.freedesktop.org Cc: intel-gfx(a)lists.freedesktop.org Cc: Chris Wilson <chris(a)chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Christian König <christian.koenig(a)amd.com> Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> Cc: Rodrigo Siqueira <rodrigosiqueiramelo(a)gmail.com> Cc: Haneen Mohammed <hamohammed.sa(a)gmail.com> Cc: Daniel Vetter <daniel(a)ffwll.ch> --- drivers/gpu/drm/vkms/vkms_crtc.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c b/drivers/gpu/drm/vkms/vkms_crtc.c index e43e4e1b268a..8124d8f2ee15 100644 --- a/drivers/gpu/drm/vkms/vkms_crtc.c +++ b/drivers/gpu/drm/vkms/vkms_crtc.c @@ -1,5 +1,7 @@ // SPDX-License-Identifier: GPL-2.0+ +#include <linux/dma-fence.h> + #include <drm/drm_atomic.h> #include <drm/drm_atomic_helper.h> #include <drm/drm_probe_helper.h> @@ -14,7 +16,9 @@ static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer) struct drm_crtc *crtc = &output->crtc; struct vkms_crtc_state *state; u64 ret_overrun; - bool ret; + bool ret, fence_cookie; + + fence_cookie = dma_fence_begin_signalling(); ret_overrun = hrtimer_forward_now(&output->vblank_hrtimer, output->period_ns); @@ -49,6 +53,8 @@ static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer) DRM_DEBUG_DRIVER("Composer worker already queued\n"); } + dma_fence_end_signalling(fence_cookie); + return HRTIMER_RESTART; } -- 2.28.0

4 years, 2 months

[PATCH 05/65] drm/atomic-helper: Add dma-fence annotations

by Daniel Vetter

This is a bit disappointing since we need to split the annotations over all the different parts. I was considering just leaking the critical section into the ->atomic_commit_tail callback of each driver. But that would mean we need to pass the fence_cookie into each driver (there's a total of 13 implementations of this hook right now), so bad flag day. And also a bit leaky abstraction. Hence just do it function-by-function. Cc: linux-media(a)vger.kernel.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: linux-rdma(a)vger.kernel.org Cc: amd-gfx(a)lists.freedesktop.org Cc: intel-gfx(a)lists.freedesktop.org Cc: Chris Wilson <chris(a)chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com> Cc: Christian König <christian.koenig(a)amd.com> Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> --- drivers/gpu/drm/drm_atomic_helper.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 549a31e6042c..23013209d4bf 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -1567,6 +1567,7 @@ EXPORT_SYMBOL(drm_atomic_helper_wait_for_flip_done); void drm_atomic_helper_commit_tail(struct drm_atomic_state *old_state) { struct drm_device *dev = old_state->dev; + bool fence_cookie = dma_fence_begin_signalling(); drm_atomic_helper_commit_modeset_disables(dev, old_state); @@ -1578,6 +1579,8 @@ void drm_atomic_helper_commit_tail(struct drm_atomic_state *old_state) drm_atomic_helper_commit_hw_done(old_state); + dma_fence_end_signalling(fence_cookie); + drm_atomic_helper_wait_for_vblanks(dev, old_state); drm_atomic_helper_cleanup_planes(dev, old_state); @@ -1597,6 +1600,7 @@ EXPORT_SYMBOL(drm_atomic_helper_commit_tail); void drm_atomic_helper_commit_tail_rpm(struct drm_atomic_state *old_state) { struct drm_device *dev = old_state->dev; + bool fence_cookie = dma_fence_begin_signalling(); drm_atomic_helper_commit_modeset_disables(dev, old_state); @@ -1609,6 +1613,8 @@ void drm_atomic_helper_commit_tail_rpm(struct drm_atomic_state *old_state) drm_atomic_helper_commit_hw_done(old_state); + dma_fence_end_signalling(fence_cookie); + drm_atomic_helper_wait_for_vblanks(dev, old_state); drm_atomic_helper_cleanup_planes(dev, old_state); @@ -1624,6 +1630,9 @@ static void commit_tail(struct drm_atomic_state *old_state) ktime_t start; s64 commit_time_ms; unsigned int i, new_self_refresh_mask = 0; + bool fence_cookie; + + fence_cookie = dma_fence_begin_signalling(); funcs = dev->mode_config.helper_private; @@ -1652,6 +1661,8 @@ static void commit_tail(struct drm_atomic_state *old_state) if (new_crtc_state->self_refresh_active) new_self_refresh_mask |= BIT(i); + dma_fence_end_signalling(fence_cookie); + if (funcs && funcs->atomic_commit_tail) funcs->atomic_commit_tail(old_state); else @@ -1810,6 +1821,7 @@ int drm_atomic_helper_commit(struct drm_device *dev, bool nonblock) { int ret; + bool fence_cookie; if (state->async_update) { ret = drm_atomic_helper_prepare_planes(dev, state); @@ -1832,6 +1844,8 @@ int drm_atomic_helper_commit(struct drm_device *dev, if (ret) return ret; + fence_cookie = dma_fence_begin_signalling(); + if (!nonblock) { ret = drm_atomic_helper_wait_for_fences(dev, state, true); if (ret) @@ -1869,6 +1883,7 @@ int drm_atomic_helper_commit(struct drm_device *dev, */ drm_atomic_state_get(state); + dma_fence_end_signalling(fence_cookie); if (nonblock) queue_work(system_unbound_wq, &state->commit_work); else @@ -1877,6 +1892,7 @@ int drm_atomic_helper_commit(struct drm_device *dev, return 0; err: + dma_fence_end_signalling(fence_cookie); drm_atomic_helper_cleanup_planes(dev, state); return ret; } -- 2.28.0

4 years, 2 months

[PATCH v3 00/23] drm/msm: de-struct_mutex-ification

by Rob Clark

From: Rob Clark <robdclark(a)chromium.org> This doesn't remove *all* the struct_mutex, but it covers the worst of it, ie. shrinker/madvise/free/retire. The submit path still uses struct_mutex, but it still needs *something* serialize a portion of the submit path, and lock_stat mostly just shows the lock contention there being with other submits. And there are a few other bits of struct_mutex usage in less critical paths (debugfs, etc). But this seems like a reasonable step in the right direction. v2: teach lockdep about shrinker locking patters (danvet) and convert to obj->resv locking (danvet) v3: fix get_vaddr locking for legacy userspace (relocs), devcoredump, and rd/hangrd Rob Clark (23): drm/msm: Fix a couple incorrect usages of get_vaddr_active() drm/msm/gem: Add obj->lock wrappers drm/msm/gem: Rename internal get_iova_locked helper drm/msm/gem: Move prototypes to msm_gem.h drm/msm/gem: Add some _locked() helpers drm/msm/gem: Move locking in shrinker path drm/msm/submit: Move copy_from_user ahead of locking bos drm/msm: Do rpm get sooner in the submit path drm/msm/gem: Switch over to obj->resv for locking drm/msm: Use correct drm_gem_object_put() in fail case drm/msm: Drop chatty trace drm/msm: Move update_fences() drm/msm: Add priv->mm_lock to protect active/inactive lists drm/msm: Document and rename preempt_lock drm/msm: Protect ring->submits with it's own lock drm/msm: Refcount submits drm/msm: Remove obj->gpu drm/msm: Drop struct_mutex from the retire path drm/msm: Drop struct_mutex in free_object() path drm/msm: Remove msm_gem_free_work drm/msm: Drop struct_mutex in madvise path drm/msm: Drop struct_mutex in shrinker path drm/msm: Don't implicit-sync if only a single ring drivers/gpu/drm/msm/adreno/a5xx_gpu.c | 6 +- drivers/gpu/drm/msm/adreno/a5xx_preempt.c | 12 +- drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 6 +- drivers/gpu/drm/msm/disp/mdp4/mdp4_crtc.c | 1 + drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c | 1 + drivers/gpu/drm/msm/dsi/dsi_host.c | 1 + drivers/gpu/drm/msm/msm_debugfs.c | 7 + drivers/gpu/drm/msm/msm_drv.c | 21 +- drivers/gpu/drm/msm/msm_drv.h | 73 +----- drivers/gpu/drm/msm/msm_fbdev.c | 1 + drivers/gpu/drm/msm/msm_gem.c | 266 +++++++++++----------- drivers/gpu/drm/msm/msm_gem.h | 133 +++++++++-- drivers/gpu/drm/msm/msm_gem_shrinker.c | 81 ++----- drivers/gpu/drm/msm/msm_gem_submit.c | 158 ++++++++----- drivers/gpu/drm/msm/msm_gpu.c | 110 +++++---- drivers/gpu/drm/msm/msm_gpu.h | 5 +- drivers/gpu/drm/msm/msm_rd.c | 2 +- drivers/gpu/drm/msm/msm_ringbuffer.c | 3 +- drivers/gpu/drm/msm/msm_ringbuffer.h | 13 +- 19 files changed, 495 insertions(+), 405 deletions(-) -- 2.26.2

4 years, 2 months

Re: [Linaro-mm-sig] WARNING in dma_map_page_attrs

by Christoph Hellwig

I don't think the merge commit makes sense here. But what we see here is that dma_map_page is called on the rxe device, without that device having a DMA mask. For now this needs a workaround in rxe, but for 5.11 I'll send a patch to remove dma-virt and just handle this case inside of the rdma core. On Wed, Oct 21, 2020 at 12:03:19PM -0700, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: c4d6fe73 Merge tag 'xarray-5.9' of git://git.infradead.org.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=14862ff0500000 > kernel config: https://syzkaller.appspot.com/x/.config?x=7d790573d3e379c4 > dashboard link: https://syzkaller.appspot.com/bug?extid=34dc2fea3478e659af01 > compiler: gcc (GCC) 10.1.0-syz 20200507 > > Unfortunately, I don't have any reproducer for this issue yet. > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+34dc2fea3478e659af01(a)syzkaller.appspotmail.com > > infiniband syz1: set active > infiniband syz1: added vcan0 > ------------[ cut here ]------------ > WARNING: CPU: 1 PID: 9851 at kernel/dma/mapping.c:149 dma_map_page_attrs+0x493/0x700 kernel/dma/mapping.c:149 > Modules linked in: > CPU: 1 PID: 9851 Comm: syz-executor.1 Not tainted 5.9.0-syzkaller #0 > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 > RIP: 0010:dma_map_page_attrs+0x493/0x700 kernel/dma/mapping.c:149 > Code: 80 3c 10 00 0f 85 ed 01 00 00 48 8b 1d 36 c3 fa 0c e9 2d fc ff ff 48 89 c3 e9 d1 fd ff ff e8 04 12 12 00 0f 0b e8 fd 11 12 00 <0f> 0b 49 c7 c4 ff ff ff ff e9 d5 fd ff ff e8 ea 11 12 00 48 8d 7b > RSP: 0018:ffffc90001546c68 EFLAGS: 00010246 > RAX: 0000000000040000 RBX: ffffffff894d0040 RCX: ffffc9000dbe4000 > RDX: 0000000000040000 RSI: ffffffff815d3b03 RDI: ffff88806a988b00 > RBP: ffff8880236cc400 R08: 0000000000000002 R09: 0000000000000000 > R10: 0000000000000002 R11: 0000000000000000 R12: ffffea00008db300 > R13: ffff88806a9886e8 R14: 00000000000004b8 R15: 0000000000000002 > FS: 00007f678fae2700(0000) GS:ffff88802ce00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f299a39b190 CR3: 0000000069f31000 CR4: 0000000000350ee0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > dma_map_single_attrs include/linux/dma-mapping.h:279 [inline] > ib_dma_map_single include/rdma/ib_verbs.h:3967 [inline] > ib_mad_post_receive_mads+0x23f/0xd60 drivers/infiniband/core/mad.c:2715 > ib_mad_port_start drivers/infiniband/core/mad.c:2862 [inline] > ib_mad_port_open drivers/infiniband/core/mad.c:3016 [inline] > ib_mad_init_device+0x72b/0x1400 drivers/infiniband/core/mad.c:3092 > add_client_context+0x405/0x5e0 drivers/infiniband/core/device.c:680 > enable_device_and_get+0x1d5/0x3c0 drivers/infiniband/core/device.c:1301 > ib_register_device drivers/infiniband/core/device.c:1376 [inline] > ib_register_device+0x7a7/0xa40 drivers/infiniband/core/device.c:1335 > rxe_register_device+0x46d/0x570 drivers/infiniband/sw/rxe/rxe_verbs.c:1182 > rxe_add+0x12fe/0x16d0 drivers/infiniband/sw/rxe/rxe.c:247 > rxe_net_add+0x8c/0xe0 drivers/infiniband/sw/rxe/rxe_net.c:507 > rxe_newlink drivers/infiniband/sw/rxe/rxe.c:269 [inline] > rxe_newlink+0xb7/0xe0 drivers/infiniband/sw/rxe/rxe.c:250 > nldev_newlink+0x30e/0x540 drivers/infiniband/core/nldev.c:1555 > rdma_nl_rcv_msg+0x367/0x690 drivers/infiniband/core/netlink.c:195 > rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline] > rdma_nl_rcv+0x2f2/0x440 drivers/infiniband/core/netlink.c:259 > netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] > netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330 > netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1919 > sock_sendmsg_nosec net/socket.c:651 [inline] > sock_sendmsg+0xcf/0x120 net/socket.c:671 > ____sys_sendmsg+0x6e8/0x810 net/socket.c:2353 > ___sys_sendmsg+0xf3/0x170 net/socket.c:2407 > __sys_sendmsg+0xe5/0x1b0 net/socket.c:2440 > do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > RIP: 0033:0x45d9f9 > Code: bd b1 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 8b b1 fb ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007f678fae1c88 EFLAGS: 00000246 ORIG_RAX: 000000000000002e > RAX: ffffffffffffffda RBX: 000000000071f480 RCX: 000000000045d9f9 > RDX: 0000000000000000 RSI: 0000000020000200 RDI: 0000000000000003 > RBP: 00000000004aab13 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 000000000075bf00 > R13: 00007ffc6f9b8bbf R14: 00007f678fac2000 R15: 0000000000000003 > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller(a)googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. ---end quoted text---

4 years, 2 months

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Linaro-mm-sig October 2020