Linaro-mm-sig October 2020

linaro-mm-sig@lists.linaro.org

13 participants
29 discussions

Re: [Linaro-mm-sig] [PATCH 3/3] RFC: dma-buf: Add an API for importing and exporting sync files (v5)

by Daniel Vetter

On Wed, Sep 30, 2020 at 11:39:06AM +0200, Michel Dänzer wrote: > On 2020-03-17 10:21 p.m., Jason Ekstrand wrote: > > Explicit synchronization is the future. At least, that seems to be what > > most userspace APIs are agreeing on at this point. However, most of our > > Linux APIs (both userspace and kernel UAPI) are currently built around > > implicit synchronization with dma-buf. While work is ongoing to change > > many of the userspace APIs and protocols to an explicit synchronization > > model, switching over piecemeal is difficult due to the number of > > potential components involved. On the kernel side, many drivers use > > dma-buf including GPU (3D/compute), display, v4l, and others. In > > userspace, we have X11, several Wayland compositors, 3D drivers, compute > > drivers (OpenCL etc.), media encode/decode, and the list goes on. > > > > This patch provides a path forward by allowing userspace to manually > > manage the fences attached to a dma-buf. Alternatively, one can think > > of this as making dma-buf's implicit synchronization simply a carrier > > for an explicit fence. This is accomplished by adding two IOCTLs to > > dma-buf for importing and exporting a sync file to/from the dma-buf. > > This way a userspace component which is uses explicit synchronization, > > such as a Vulkan driver, can manually set the write fence on a buffer > > before handing it off to an implicitly synchronized component such as a > > Wayland compositor or video encoder. In this way, each of the different > > components can be upgraded to an explicit synchronization model one at a > > time as long as the userspace pieces connecting them are aware of it and > > import/export fences at the right times. > > > > There is a potential race condition with this API if userspace is not > > careful. A typical use case for implicit synchronization is to wait for > > the dma-buf to be ready, use it, and then signal it for some other > > component. Because a sync_file cannot be created until it is guaranteed > > to complete in finite time, userspace can only signal the dma-buf after > > it has already submitted the work which uses it to the kernel and has > > received a sync_file back. There is no way to atomically submit a > > wait-use-signal operation. This is not, however, really a problem with > > this API so much as it is a problem with explicit synchronization > > itself. The way this is typically handled is to have very explicit > > ownership transfer points in the API or protocol which ensure that only > > one component is using it at any given time. Both X11 (via the PRESENT > > extension) and Wayland provide such ownership transfer points via > > explicit present and idle messages. > > > > The decision was intentionally made in this patch to make the import and > > export operations IOCTLs on the dma-buf itself rather than as a DRM > > IOCTL. This makes it the import/export operation universal across all > > components which use dma-buf including GPU, display, v4l, and others. > > It also means that a userspace component can do the import/export > > without access to the DRM fd which may be tricky to get in cases where > > the client communicates with DRM via a userspace API such as OpenGL or > > Vulkan. At a future date we may choose to add direct import/export APIs > > to components such as drm_syncobj to avoid allocating a file descriptor > > and going through two ioctls. However, that seems to be something of a > > micro-optimization as import/export operations are likely to happen at a > > rate of a few per frame of rendered or decoded video. > > > > v2 (Jason Ekstrand): > > - Use a wrapper dma_fence_array of all fences including the new one > > when importing an exclusive fence. > > > > v3 (Jason Ekstrand): > > - Lock around setting shared fences as well as exclusive > > - Mark SIGNAL_SYNC_FILE as a read-write ioctl. > > - Initialize ret to 0 in dma_buf_wait_sync_file > > > > v4 (Jason Ekstrand): > > - Use the new dma_resv_get_singleton helper > > > > v5 (Jason Ekstrand): > > - Rename the IOCTLs to import/export rather than wait/signal > > - Drop the WRITE flag and always get/set the exclusive fence > > > > Signed-off-by: Jason Ekstrand <jason(a)jlekstrand.net> > > What's the status of this? DMA_BUF_IOCTL_EXPORT_SYNC_FILE would be useful > for Wayland compositors to wait for client buffers to become ready without > being prone to getting delayed by later HW access to them, so it would be > nice to merge that at least (if DMA_BUF_IOCTL_IMPORT_SYNC_FILE is still > controversial). I think the missing bits are just the usual stuff - igt testcases - userspace using the new ioctls - review of the entire pile I don't think there's any fundamental objections aside from "no one ever pushed this over the finish line". Cheers, Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch

3 years, 9 months

[PATCH 1/2] mm: mmap: fix fput in error path v2

by Christian König

Patch "495c10cc1c0c CHROMIUM: dma-buf: restore args..." adds a workaround for a bug in mmap_region. As the comment states ->mmap() callback can change vma->vm_file and so we might call fput() on the wrong file. Revert the workaround and proper fix this in mmap_region. v2: drop the extra if in dma_buf_mmap as well Signed-off-by: Christian König <christian.koenig(a)amd.com> Reviewed-by: Jason Gunthorpe <jgg(a)nvidia.com> --- drivers/dma-buf/dma-buf.c | 20 +++----------------- mm/mmap.c | 2 +- 2 files changed, 4 insertions(+), 18 deletions(-) diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index a6ba4d598f0e..08630d057cf2 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -1143,9 +1143,6 @@ EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access); int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, unsigned long pgoff) { - struct file *oldfile; - int ret; - if (WARN_ON(!dmabuf || !vma)) return -EINVAL; @@ -1163,22 +1160,11 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, return -EINVAL; /* readjust the vma */ - get_file(dmabuf->file); - oldfile = vma->vm_file; - vma->vm_file = dmabuf->file; + fput(vma->vm_file); + vma->vm_file = get_file(dmabuf->file); vma->vm_pgoff = pgoff; - ret = dmabuf->ops->mmap(dmabuf, vma); - if (ret) { - /* restore old parameters on failure */ - vma->vm_file = oldfile; - fput(dmabuf->file); - } else { - if (oldfile) - fput(oldfile); - } - return ret; - + return dmabuf->ops->mmap(dmabuf, vma); } EXPORT_SYMBOL_GPL(dma_buf_mmap); diff --git a/mm/mmap.c b/mm/mmap.c index 40248d84ad5f..3a2670d73355 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1852,8 +1852,8 @@ unsigned long mmap_region(struct file *file, unsigned long addr, return addr; unmap_and_free_vma: + fput(vma->vm_file); vma->vm_file = NULL; - fput(file); /* Undo any partial mapping done by a device driver. */ unmap_region(mm, vma, prev, vma->vm_start, vma->vm_end); -- 2.17.1

4 years, 1 month

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

by hch＠lst.de

On Tue, Oct 27, 2020 at 12:52:30PM +0000, Parav Pandit wrote: > > > From: hch(a)lst.de <hch(a)lst.de> > > Sent: Tuesday, October 27, 2020 1:41 PM > > > > On Mon, Oct 26, 2020 at 05:23:48AM +0000, Parav Pandit wrote: > > > Hi Christoph, > > > > > > > From: Jakub Kicinski <kuba(a)kernel.org> > > > > Sent: Saturday, October 24, 2020 11:45 PM > > > > > > > > CC: rdma, looks like rdma from the stack trace > > > > > > > > On Fri, 23 Oct 2020 20:07:17 -0700 syzbot wrote: > > > > > syzbot has found a reproducer for the following issue on: > > > > > > > > > > HEAD commit: 3cb12d27 Merge tag 'net-5.10-rc1' of > > git://git.kernel.org/.. > > > > > > In [1] you mentioned that dma_mask should not be set for dma_virt_ops. > > > So patch [2] removed it. > > > > > > But check to validate the dma mask for all dma_ops was added in [3]. > > > > > > What is the right way? Did I misunderstood your comment about > > dma_mask in [1]? > > > > No, I did not say we don't need the mask. I said copying over the various > > dma-related fields from the parent is bogus. > > > > I think rxe (and ther other drivers/infiniband/sw drivers) need a simple > > dma_coerce_mask_and_coherent and nothing else. > > I see. Does below fix make sense? > Is DMA_MASK_NONE correct? DMA_MASK_NONE is gone in 5.10. I think you want DMA_BIT_MASK(64). That isn't actually correct for 32-bit platforms, but good enough.

4 years, 1 month

Re: [Linaro-mm-sig] [PATCH] drm/shme-helpers: Fix dma_buf_mmap forwarding bug

by Daniel Vetter

On Wed, Oct 28, 2020 at 09:44:15AM +0100, Boris Brezillon wrote: > On Tue, 27 Oct 2020 22:49:22 +0100 > Daniel Vetter <daniel.vetter(a)ffwll.ch> wrote: > > > When we forward an mmap to the dma_buf exporter, they get to own > > everything. Unfortunately drm_gem_mmap_obj() overwrote > > vma->vm_private_data after the driver callback, wreaking the > > exporter complete. This was noticed because vb2_common_vm_close blew > > up on mali gpu with panfrost after commit 26d3ac3cb04d > > ("drm/shmem-helpers: Redirect mmap for imported dma-buf"). > > > > Unfortunately drm_gem_mmap_obj also acquires a surplus reference that > > we need to drop in shmem helpers, which is a bit of a mislayer > > situation. Maybe the entire dma_buf_mmap forwarding should be pulled > > into core gem code. > > > > Note that the only two other drivers which forward mmap in their own > > code (etnaviv and exynos) get this somewhat right by overwriting the > > gem mmap code. But they seem to still have the leak. This might be a > > good excuse to move these drivers over to shmem helpers completely. > > > > Note to stable team: There's a trivial context conflict with > > d693def4fd1c ("drm: Remove obsolete GEM and PRIME callbacks from > > struct drm_driver"). I'm assuming it's clear where to put the first > > hunk, otherwise I can send a 5.9 version of this. > > > > Cc: Christian König <christian.koenig(a)amd.com> > > Cc: Sumit Semwal <sumit.semwal(a)linaro.org> > > Cc: Lucas Stach <l.stach(a)pengutronix.de> > > Cc: Russell King <linux+etnaviv(a)armlinux.org.uk> > > Cc: Christian Gmeiner <christian.gmeiner(a)gmail.com> > > Cc: Inki Dae <inki.dae(a)samsung.com> > > Cc: Joonyoung Shim <jy0922.shim(a)samsung.com> > > Cc: Seung-Woo Kim <sw0312.kim(a)samsung.com> > > Cc: Kyungmin Park <kyungmin.park(a)samsung.com> > > Fixes: 26d3ac3cb04d ("drm/shmem-helpers: Redirect mmap for imported dma-buf") > > Cc: Boris Brezillon <boris.brezillon(a)collabora.com> > > Reviewed-by: Boris Brezillon <boris.brezillon(a)collabora.com> Patch pushed to drm-misc-fixes, thanks for taking a look. -Daniel > > > Cc: Thomas Zimmermann <tzimmermann(a)suse.de> > > Cc: Gerd Hoffmann <kraxel(a)redhat.com> > > Cc: Rob Herring <robh(a)kernel.org> > > Cc: dri-devel(a)lists.freedesktop.org > > Cc: linux-media(a)vger.kernel.org > > Cc: linaro-mm-sig(a)lists.linaro.org > > Cc: <stable(a)vger.kernel.org> # v5.9+ > > Reported-and-tested-by: piotr.oniszczuk(a)gmail.com > > Cc: piotr.oniszczuk(a)gmail.com > > Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> > > --- > > drivers/gpu/drm/drm_gem.c | 4 ++-- > > drivers/gpu/drm/drm_gem_shmem_helper.c | 7 ++++++- > > 2 files changed, 8 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c > > index 1da67d34e55d..d586068f5509 100644 > > --- a/drivers/gpu/drm/drm_gem.c > > +++ b/drivers/gpu/drm/drm_gem.c > > @@ -1076,6 +1076,8 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size, > > */ > > drm_gem_object_get(obj); > > > > + vma->vm_private_data = obj; > > + > > if (obj->funcs->mmap) { > > ret = obj->funcs->mmap(obj, vma); > > if (ret) { > > @@ -1096,8 +1098,6 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size, > > vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot); > > } > > > > - vma->vm_private_data = obj; > > - > > return 0; > > } > > EXPORT_SYMBOL(drm_gem_mmap_obj); > > diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c > > index fb11df7aced5..8233bda4692f 100644 > > --- a/drivers/gpu/drm/drm_gem_shmem_helper.c > > +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c > > @@ -598,8 +598,13 @@ int drm_gem_shmem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) > > /* Remove the fake offset */ > > vma->vm_pgoff -= drm_vma_node_start(&obj->vma_node); > > > > - if (obj->import_attach) > > + if (obj->import_attach) { > > + /* Drop the reference drm_gem_mmap_obj() acquired.*/ > > + drm_gem_object_put(obj); > > + vma->vm_private_data = NULL; > > + > > return dma_buf_mmap(obj->dma_buf, vma, 0); > > + } > > > > shmem = to_drm_gem_shmem_obj(obj); > > > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch

4 years, 1 month

[PATCH] drm/shme-helpers: Fix dma_buf_mmap forwarding bug

by Daniel Vetter

When we forward an mmap to the dma_buf exporter, they get to own everything. Unfortunately drm_gem_mmap_obj() overwrote vma->vm_private_data after the driver callback, wreaking the exporter complete. This was noticed because vb2_common_vm_close blew up on mali gpu with panfrost after commit 26d3ac3cb04d ("drm/shmem-helpers: Redirect mmap for imported dma-buf"). Unfortunately drm_gem_mmap_obj also acquires a surplus reference that we need to drop in shmem helpers, which is a bit of a mislayer situation. Maybe the entire dma_buf_mmap forwarding should be pulled into core gem code. Note that the only two other drivers which forward mmap in their own code (etnaviv and exynos) get this somewhat right by overwriting the gem mmap code. But they seem to still have the leak. This might be a good excuse to move these drivers over to shmem helpers completely. Note to stable team: There's a trivial context conflict with d693def4fd1c ("drm: Remove obsolete GEM and PRIME callbacks from struct drm_driver"). I'm assuming it's clear where to put the first hunk, otherwise I can send a 5.9 version of this. Cc: Christian König <christian.koenig(a)amd.com> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: Lucas Stach <l.stach(a)pengutronix.de> Cc: Russell King <linux+etnaviv(a)armlinux.org.uk> Cc: Christian Gmeiner <christian.gmeiner(a)gmail.com> Cc: Inki Dae <inki.dae(a)samsung.com> Cc: Joonyoung Shim <jy0922.shim(a)samsung.com> Cc: Seung-Woo Kim <sw0312.kim(a)samsung.com> Cc: Kyungmin Park <kyungmin.park(a)samsung.com> Fixes: 26d3ac3cb04d ("drm/shmem-helpers: Redirect mmap for imported dma-buf") Cc: Boris Brezillon <boris.brezillon(a)collabora.com> Cc: Thomas Zimmermann <tzimmermann(a)suse.de> Cc: Gerd Hoffmann <kraxel(a)redhat.com> Cc: Rob Herring <robh(a)kernel.org> Cc: dri-devel(a)lists.freedesktop.org Cc: linux-media(a)vger.kernel.org Cc: linaro-mm-sig(a)lists.linaro.org Cc: <stable(a)vger.kernel.org> # v5.9+ Reported-and-tested-by: piotr.oniszczuk(a)gmail.com Cc: piotr.oniszczuk(a)gmail.com Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> --- drivers/gpu/drm/drm_gem.c | 4 ++-- drivers/gpu/drm/drm_gem_shmem_helper.c | 7 ++++++- 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index 1da67d34e55d..d586068f5509 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -1076,6 +1076,8 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size, */ drm_gem_object_get(obj); + vma->vm_private_data = obj; + if (obj->funcs->mmap) { ret = obj->funcs->mmap(obj, vma); if (ret) { @@ -1096,8 +1098,6 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size, vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot); } - vma->vm_private_data = obj; - return 0; } EXPORT_SYMBOL(drm_gem_mmap_obj); diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c index fb11df7aced5..8233bda4692f 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -598,8 +598,13 @@ int drm_gem_shmem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) /* Remove the fake offset */ vma->vm_pgoff -= drm_vma_node_start(&obj->vma_node); - if (obj->import_attach) + if (obj->import_attach) { + /* Drop the reference drm_gem_mmap_obj() acquired.*/ + drm_gem_object_put(obj); + vma->vm_private_data = NULL; + return dma_buf_mmap(obj->dma_buf, vma, 0); + } shmem = to_drm_gem_shmem_obj(obj); -- 2.28.0

4 years, 1 month

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

by hch＠lst.de

On Mon, Oct 26, 2020 at 05:23:48AM +0000, Parav Pandit wrote: > Hi Christoph, > > > From: Jakub Kicinski <kuba(a)kernel.org> > > Sent: Saturday, October 24, 2020 11:45 PM > > > > CC: rdma, looks like rdma from the stack trace > > > > On Fri, 23 Oct 2020 20:07:17 -0700 syzbot wrote: > > > syzbot has found a reproducer for the following issue on: > > > > > > HEAD commit: 3cb12d27 Merge tag 'net-5.10-rc1' of git://git.kernel.org/.. > > In [1] you mentioned that dma_mask should not be set for dma_virt_ops. > So patch [2] removed it. > > But check to validate the dma mask for all dma_ops was added in [3]. > > What is the right way? Did I misunderstood your comment about dma_mask in [1]? No, I did not say we don't need the mask. I said copying over the various dma-related fields from the parent is bogus. I think rxe (and ther other drivers/infiniband/sw drivers) need a simple dma_coerce_mask_and_coherent and nothing else.

4 years, 1 month

[PATCH v4 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 v4: couple minor review comments (krh), fix deadlock with imported dma-buf's (ie. from v4l2, etc) 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 | 271 +++++++++++----------- 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 | 164 ++++++++----- 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, 506 insertions(+), 405 deletions(-) -- 2.26.2

4 years, 2 months

[PATCH 23/65] drm/i915: Annotate dma_fence_work

by Daniel Vetter

i915 does tons of allocations from this worker, which lockdep catches. Also generic infrastructure like this with big potential for how dma_fence or other cross driver contracts work, really should be reviewed on dri-devel. Implementing custom wheels for everything within the driver is a classic case of "platform problem" [1]. Which in upstream we really shouldn't have. Since there's no quick way to solve these splats (dma_fence_work is used a bunch in basic buffer management and command submission) like for amdgpu, I'm giving up at this point here. Annotating i915 scheduler and gpu reset could would be interesting, but since lockdep is one-shot we can't see what surprises would lurk there. 1: https://lwn.net/Articles/443531/ 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/i915/i915_sw_fence_work.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_sw_fence_work.c b/drivers/gpu/drm/i915/i915_sw_fence_work.c index a3a81bb8f2c3..5b74acadaef5 100644 --- a/drivers/gpu/drm/i915/i915_sw_fence_work.c +++ b/drivers/gpu/drm/i915/i915_sw_fence_work.c @@ -17,12 +17,15 @@ static void fence_work(struct work_struct *work) { struct dma_fence_work *f = container_of(work, typeof(*f), work); int err; + bool fence_cookie; + fence_cookie = dma_fence_begin_signalling(); err = f->ops->work(f); if (err) dma_fence_set_error(&f->dma, err); fence_complete(f); + dma_fence_end_signalling(fence_cookie); dma_fence_put(&f->dma); } -- 2.28.0

4 years, 2 months

[PATCH 22/65] Revert "drm/amdgpu: add fbdev suspend/resume on gpu reset"

by Daniel Vetter

This is one from the department of "maybe play lottery if you hit this, karma compensation might work". Or at least lockdep ftw! This reverts commit 565d1941557756a584ac357d945bc374d5fcd1d0. It's not quite as low-risk as the commit message claims, because this grabs console_lock, which might be held when we allocate memory, which might never happen because the dma_fence_wait() is stuck waiting on our gpu reset: [ 136.763714] ====================================================== [ 136.763714] WARNING: possible circular locking dependency detected [ 136.763715] 5.7.0-rc3+ #346 Tainted: G W [ 136.763716] ------------------------------------------------------ [ 136.763716] kworker/2:3/682 is trying to acquire lock: [ 136.763716] ffffffff8226f140 (console_lock){+.+.}-{0:0}, at: drm_fb_helper_set_suspend_unlocked+0x7b/0xa0 [drm_kms_helper] [ 136.763723] but task is already holding lock: [ 136.763724] ffffffff82318c80 (dma_fence_map){++++}-{0:0}, at: drm_sched_job_timedout+0x25/0xf0 [gpu_sched] [ 136.763726] which lock already depends on the new lock. [ 136.763726] the existing dependency chain (in reverse order) is: [ 136.763727] -> #2 (dma_fence_map){++++}-{0:0}: [ 136.763730] __dma_fence_might_wait+0x41/0xb0 [ 136.763732] dma_resv_lockdep+0x171/0x202 [ 136.763734] do_one_initcall+0x5d/0x2f0 [ 136.763736] kernel_init_freeable+0x20d/0x26d [ 136.763738] kernel_init+0xa/0xfb [ 136.763740] ret_from_fork+0x27/0x50 [ 136.763740] -> #1 (fs_reclaim){+.+.}-{0:0}: [ 136.763743] fs_reclaim_acquire.part.0+0x25/0x30 [ 136.763745] kmem_cache_alloc_trace+0x2e/0x6e0 [ 136.763747] device_create_groups_vargs+0x52/0xf0 [ 136.763747] device_create+0x49/0x60 [ 136.763749] fb_console_init+0x25/0x145 [ 136.763750] fbmem_init+0xcc/0xe2 [ 136.763750] do_one_initcall+0x5d/0x2f0 [ 136.763751] kernel_init_freeable+0x20d/0x26d [ 136.763752] kernel_init+0xa/0xfb [ 136.763753] ret_from_fork+0x27/0x50 [ 136.763753] -> #0 (console_lock){+.+.}-{0:0}: [ 136.763755] __lock_acquire+0x1241/0x23f0 [ 136.763756] lock_acquire+0xad/0x370 [ 136.763757] console_lock+0x47/0x70 [ 136.763761] drm_fb_helper_set_suspend_unlocked+0x7b/0xa0 [drm_kms_helper] [ 136.763809] amdgpu_device_gpu_recover.cold+0x21e/0xe7b [amdgpu] [ 136.763850] amdgpu_job_timedout+0xfb/0x150 [amdgpu] [ 136.763851] drm_sched_job_timedout+0x8a/0xf0 [gpu_sched] [ 136.763852] process_one_work+0x23c/0x580 [ 136.763853] worker_thread+0x50/0x3b0 [ 136.763854] kthread+0x12e/0x150 [ 136.763855] ret_from_fork+0x27/0x50 [ 136.763855] other info that might help us debug this: [ 136.763856] Chain exists of: console_lock --> fs_reclaim --> dma_fence_map [ 136.763857] Possible unsafe locking scenario: [ 136.763857] CPU0 CPU1 [ 136.763857] ---- ---- [ 136.763857] lock(dma_fence_map); [ 136.763858] lock(fs_reclaim); [ 136.763858] lock(dma_fence_map); [ 136.763858] lock(console_lock); [ 136.763859] *** DEADLOCK *** [ 136.763860] 4 locks held by kworker/2:3/682: [ 136.763860] #0: ffff8887fb81c938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1bc/0x580 [ 136.763862] #1: ffffc90000cafe58 ((work_completion)(&(&sched->work_tdr)->work)){+.+.}-{0:0}, at: process_one_work+0x1bc/0x580 [ 136.763863] #2: ffffffff82318c80 (dma_fence_map){++++}-{0:0}, at: drm_sched_job_timedout+0x25/0xf0 [gpu_sched] [ 136.763865] #3: ffff8887ab621748 (&adev->lock_reset){+.+.}-{3:3}, at: amdgpu_device_gpu_recover.cold+0x5ab/0xe7b [amdgpu] [ 136.763914] stack backtrace: [ 136.763915] CPU: 2 PID: 682 Comm: kworker/2:3 Tainted: G W 5.7.0-rc3+ #346 [ 136.763916] Hardware name: System manufacturer System Product Name/PRIME X370-PRO, BIOS 4011 04/19/2018 [ 136.763918] Workqueue: events drm_sched_job_timedout [gpu_sched] [ 136.763919] Call Trace: [ 136.763922] dump_stack+0x8f/0xd0 [ 136.763924] check_noncircular+0x162/0x180 [ 136.763926] __lock_acquire+0x1241/0x23f0 [ 136.763927] lock_acquire+0xad/0x370 [ 136.763932] ? drm_fb_helper_set_suspend_unlocked+0x7b/0xa0 [drm_kms_helper] [ 136.763933] ? mark_held_locks+0x2d/0x80 [ 136.763934] ? _raw_spin_unlock_irqrestore+0x46/0x60 [ 136.763936] console_lock+0x47/0x70 [ 136.763940] ? drm_fb_helper_set_suspend_unlocked+0x7b/0xa0 [drm_kms_helper] [ 136.763944] drm_fb_helper_set_suspend_unlocked+0x7b/0xa0 [drm_kms_helper] [ 136.763993] amdgpu_device_gpu_recover.cold+0x21e/0xe7b [amdgpu] [ 136.764036] amdgpu_job_timedout+0xfb/0x150 [amdgpu] [ 136.764038] drm_sched_job_timedout+0x8a/0xf0 [gpu_sched] [ 136.764040] process_one_work+0x23c/0x580 [ 136.764041] worker_thread+0x50/0x3b0 [ 136.764042] ? process_one_work+0x580/0x580 [ 136.764044] kthread+0x12e/0x150 [ 136.764045] ? kthread_create_worker_on_cpu+0x70/0x70 [ 136.764046] ret_from_fork+0x27/0x50 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_device.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index 029a026ecfa9..935116614884 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -4330,8 +4330,6 @@ static int amdgpu_do_asic_reset(struct amdgpu_hive_info *hive, if (r) goto out; - amdgpu_fbdev_set_suspend(tmp_adev, 0); - /* * The GPU enters bad state once faulty pages * by ECC has reached the threshold, and ras @@ -4590,8 +4588,6 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev, */ amdgpu_unregister_gpu_instance(tmp_adev); - amdgpu_fbdev_set_suspend(tmp_adev, 1); - /* disable ras on ALL IPs */ if (!need_emergency_restart && amdgpu_device_ip_need_full_reset(tmp_adev)) -- 2.28.0

4 years, 2 months

[PATCH 21/65] drm/amdgpu: use dma-fence annotations for gpu reset code

by Daniel Vetter

To improve coverage also annotate the gpu reset code itself, since that's called from other places than drm/scheduler (which is already annotated). Annotations nests, so this doesn't break anything, and allows easier testing. 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)ffwll.ch> --- drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index e8b41756c9f9..029a026ecfa9 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -4496,6 +4496,9 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev, int i, r = 0; bool need_emergency_restart = false; bool audio_suspended = false; + bool fence_cookie; + + fence_cookie = dma_fence_begin_signalling(); /** * Special case: RAS triggered and full reset isn't supported @@ -4529,6 +4532,7 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev, DRM_INFO("Bailing on TDR for s_job:%llx, hive: %llx as another already in progress", job ? job->base.id : -1, hive->hive_id); amdgpu_put_xgmi_hive(hive); + dma_fence_end_signalling(fence_cookie); return 0; } mutex_lock(&hive->hive_lock); @@ -4541,8 +4545,10 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev, */ INIT_LIST_HEAD(&device_list); if (adev->gmc.xgmi.num_physical_nodes > 1) { - if (!hive) + if (!hive) { + dma_fence_end_signalling(fence_cookie); return -ENODEV; + } if (!list_is_first(&adev->gmc.xgmi.head, &hive->device_list)) list_rotate_to_front(&adev->gmc.xgmi.head, &hive->device_list); device_list_handle = &hive->device_list; @@ -4556,8 +4562,6 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev, if (!amdgpu_device_lock_adev(tmp_adev, hive)) { dev_info(tmp_adev->dev, "Bailing on TDR for s_job:%llx, as another already in progress", job ? job->base.id : -1); - r = 0; - goto skip_recovery; } /* @@ -4699,6 +4703,7 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev, if (r) dev_info(adev->dev, "GPU reset end with ret = %d\n", r); + dma_fence_end_signalling(fence_cookie); return r; } -- 2.28.0

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Linaro-mm-sig October 2020