Linaro-mm-sig

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2541 discussions

Re: [Linaro-mm-sig] [PATCH v3 1/2] habanalabs: define uAPI to export FD for DMA-BUF

by Jason Gunthorpe

On Wed, Jun 23, 2021 at 09:43:04PM +0300, Oded Gabbay wrote: > Can you please explain why it is so important to (allow) access them > through the CPU ? It is not so much important, as it reflects significant design choices that are already tightly baked into alot of our stacks. A SGL is CPU accessible by design - that is baked into this thing and places all over the place assume it. Even in RDMA we have RXE/SWI/HFI1/qib that might want to use the CPU side (grep for sg_page to see) So, the thing at the top of the stack - in this case the gaudi driver - simply can't assume what the rest of the stack is going to do and omit the CPU side. It breaks everything. Logan's patch series is the most fully developed way out of this predicament so far. > The whole purpose is that the other device accesses my device, > bypassing the CPU. Sure, but you don't know that will happen, or if it is even possible in any given system configuration. The purpose is to allow for that optimization when possible, not exclude CPU based approaches. Jason

3 years, 6 months

Re: [Linaro-mm-sig] [PATCH v3 1/2] habanalabs: define uAPI to export FD for DMA-BUF

by Jason Gunthorpe

On Tue, Jun 22, 2021 at 11:42:27AM +0300, Oded Gabbay wrote: > On Tue, Jun 22, 2021 at 9:37 AM Christian König > <ckoenig.leichtzumerken(a)gmail.com> wrote: > > > > Am 22.06.21 um 01:29 schrieb Jason Gunthorpe: > > > On Mon, Jun 21, 2021 at 10:24:16PM +0300, Oded Gabbay wrote: > > > > > >> Another thing I want to emphasize is that we are doing p2p only > > >> through the export/import of the FD. We do *not* allow the user to > > >> mmap the dma-buf as we do not support direct IO. So there is no access > > >> to these pages through the userspace. > > > Arguably mmaping the memory is a better choice, and is the direction > > > that Logan's series goes in. Here the use of DMABUF was specifically > > > designed to allow hitless revokation of the memory, which this isn't > > > even using. > > > > The major problem with this approach is that DMA-buf is also used for > > memory which isn't CPU accessible. That isn't an issue here because the memory is only intended to be used with P2P transfers so it must be CPU accessible. > > That was one of the reasons we didn't even considered using the mapping > > memory approach for GPUs. Well, now we have DEVICE_PRIVATE memory that can meet this need too.. Just nobody has wired it up to hmm_range_fault() > > > So you are taking the hit of very limited hardware support and reduced > > > performance just to squeeze into DMABUF.. > > Thanks Jason for the clarification, but I honestly prefer to use > DMA-BUF at the moment. > It gives us just what we need (even more than what we need as you > pointed out), it is *already* integrated and tested in the RDMA > subsystem, and I'm feeling comfortable using it as I'm somewhat > familiar with it from my AMD days. You still have the issue that this patch is doing all of this P2P stuff wrong - following the already NAK'd AMD approach. > I'll go and read Logan's patch-set to see if that will work for us in > the future. Please remember, as Daniel said, we don't have struct page > backing our device memory, so if that is a requirement to connect to > Logan's work, then I don't think we will want to do it at this point. It is trivial to get the struct page for a PCI BAR. Jason

3 years, 6 months

[PATCH 02/15] dma-buf: Switch to inline kerneldoc

by Daniel Vetter

Also review & update everything while we're at it. This is prep work to smash a ton of stuff into the kerneldoc for @resv. Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: "Christian König" <christian.koenig(a)amd.com> Cc: Alex Deucher <alexander.deucher(a)amd.com> Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: Dave Airlie <airlied(a)redhat.com> Cc: Nirmoy Das <nirmoy.das(a)amd.com> Cc: Deepak R Varma <mh12gx2825(a)gmail.com> Cc: Chen Li <chenli(a)uniontech.com> Cc: Kevin Wang <kevin1.wang(a)amd.com> Cc: linux-media(a)vger.kernel.org Cc: linaro-mm-sig(a)lists.linaro.org --- include/linux/dma-buf.h | 107 +++++++++++++++++++++++++++++++--------- 1 file changed, 83 insertions(+), 24 deletions(-) diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 92eec38a03aa..6d18b9e448b9 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -289,28 +289,6 @@ struct dma_buf_ops { /** * struct dma_buf - shared buffer object - * @size: size of the buffer; invariant over the lifetime of the buffer. - * @file: file pointer used for sharing buffers across, and for refcounting. - * @attachments: list of dma_buf_attachment that denotes all devices attached, - * protected by dma_resv lock. - * @ops: dma_buf_ops associated with this buffer object. - * @lock: used internally to serialize list manipulation, attach/detach and - * vmap/unmap - * @vmapping_counter: used internally to refcnt the vmaps - * @vmap_ptr: the current vmap ptr if vmapping_counter > 0 - * @exp_name: name of the exporter; useful for debugging. - * @name: userspace-provided name; useful for accounting and debugging, - * protected by @resv. - * @name_lock: spinlock to protect name access - * @owner: pointer to exporter module; used for refcounting when exporter is a - * kernel module. - * @list_node: node for dma_buf accounting and debugging. - * @priv: exporter specific private data for this buffer object. - * @resv: reservation object linked to this dma-buf - * @poll: for userspace poll support - * @cb_excl: for userspace poll support - * @cb_shared: for userspace poll support - * @sysfs_entry: for exposing information about this buffer in sysfs. * The attachment_uid member of @sysfs_entry is protected by dma_resv lock * and is incremented on each attach. * @@ -324,24 +302,100 @@ struct dma_buf_ops { * Device DMA access is handled by the separate &struct dma_buf_attachment. */ struct dma_buf { + /** + * @size: + * + * Size of the buffer; invariant over the lifetime of the buffer. + */ size_t size; + + /** + * @file: + * + * File pointer used for sharing buffers across, and for refcounting. + * See dma_buf_get() and dma_buf_put(). + */ struct file *file; + + /** + * @attachments: + * + * List of dma_buf_attachment that denotes all devices attached, + * protected by &dma_resv lock @resv. + */ struct list_head attachments; + + /** @ops: dma_buf_ops associated with this buffer object. */ const struct dma_buf_ops *ops; + + /** + * @lock: + * + * Used internally to serialize list manipulation, attach/detach and + * vmap/unmap. Note that in many cases this is superseeded by + * dma_resv_lock() on @resv. + */ struct mutex lock; + + /** + * @vmapping_counter: + * + * Used internally to refcnt the vmaps returned by dma_buf_vmap(). + * Protected by @lock. + */ unsigned vmapping_counter; + + /** + * @vmap_ptr: + * The current vmap ptr if @vmapping_counter > 0. Protected by @lock. + */ struct dma_buf_map vmap_ptr; + + /** + * @exp_name: + * + * Name of the exporter; useful for debugging. See the + * DMA_BUF_SET_NAME IOCTL. + */ const char *exp_name; + + /** + * @name: + * + * Userspace-provided name; useful for accounting and debugging, + * protected by dma_resv_lock() on @resv and @name_lock for read access. + */ const char *name; + + /** @name_lock: Spinlock to protect name acces for read access. */ spinlock_t name_lock; + + /** + * @owner: + * + * Pointer to exporter module; used for refcounting when exporter is a + * kernel module. + */ struct module *owner; + + /** @list_node: node for dma_buf accounting and debugging. */ struct list_head list_node; + + /** @priv: exporter specific private data for this buffer object. */ void *priv; + + /** + * @resv: + * + * Reservation object linked to this dma-buf. + */ struct dma_resv *resv; - /* poll support */ + /** @poll: for userspace poll support */ wait_queue_head_t poll; + /** @cb_excl: for userspace poll support */ + /** @cb_shared: for userspace poll support */ struct dma_buf_poll_cb_t { struct dma_fence_cb cb; wait_queue_head_t *poll; @@ -349,7 +403,12 @@ struct dma_buf { __poll_t active; } cb_excl, cb_shared; #ifdef CONFIG_DMABUF_SYSFS_STATS - /* for sysfs stats */ + /** + * @sysfs_entry: + * + * For exposing information about this buffer in sysfs. See also + * `DMA-BUF statistics`_ for the uapi this enables. + */ struct dma_buf_sysfs_entry { struct kobject kobj; struct dma_buf *dmabuf; -- 2.32.0.rc2

3 years, 6 months

[PATCH 15/15] RFC: drm/amdgpu: Implement a proper implicit fencing uapi

by Daniel Vetter

WARNING: Absolutely untested beyond "gcc isn't dying in agony". Implicit fencing done properly needs to treat the implicit fencing slots like a funny kind of IPC mailbox. In other words it needs to be explicitly. This is the only way it will mesh well with explicit fencing userspace like vk, and it's also the bare minimum required to be able to manage anything else that wants to use the same buffer on multiple engines in parallel, and still be able to share it through implicit sync. amdgpu completely lacks such an uapi. Fix this. Luckily the concept of ignoring implicit fences exists already, and takes care of all the complexities of making sure that non-optional fences (like bo moves) are not ignored. This support was added in commit 177ae09b5d699a5ebd1cafcee78889db968abf54 Author: Andres Rodriguez <andresx7(a)gmail.com> Date: Fri Sep 15 20:44:06 2017 -0400 drm/amdgpu: introduce AMDGPU_GEM_CREATE_EXPLICIT_SYNC v2 Unfortuantely it's the wrong semantics, because it's a bo flag and disables implicit sync on an allocated buffer completely. We _do_ want implicit sync, but control it explicitly. For this we need a flag on the drm_file, so that a given userspace (like vulkan) can manage the implicit sync slots explicitly. The other side of the pipeline (compositor, other process or just different stage in a media pipeline in the same process) can then either do the same, or fully participate in the implicit sync as implemented by the kernel by default. By building on the existing flag for buffers we avoid any issues with opening up additional security concerns - anything this new flag here allows is already. All drivers which supports this concept of a userspace-specific opt-out of implicit sync have a flag in their CS ioctl, but in reality that turned out to be a bit too inflexible. See the discussion below, let's try to do a bit better for amdgpu. This alone only allows us to completely avoid any stalls due to implicit sync, it does not yet allow us to use implicit sync as a strange form of IPC for sync_file. For that we need two more pieces: - a way to get the current implicit sync fences out of a buffer. Could be done in a driver ioctl, but everyone needs this, and generally a dma-buf is involved anyway to establish the sharing. So an ioctl on the dma-buf makes a ton more sense: https://lore.kernel.org/dri-devel/20210520190007.534046-4-jason@jlekstrand.… Current drivers in upstream solves this by having the opt-out flag on their CS ioctl. This has the downside that very often the CS which must actually stall for the implicit fence is run a while after the implicit fence point was logically sampled per the api spec (vk passes an explicit syncobj around for that afaiui), and so results in oversync. Converting the implicit sync fences into a snap-shot sync_file is actually accurate. - Simillar we need to be able to set the exclusive implicit fence. Current drivers again do this with a CS ioctl flag, with again the same problems that the time the CS happens additional dependencies have been added. An explicit ioctl to only insert a sync_file (while respecting the rules for how exclusive and shared fence slots must be update in struct dma_resv) is much better. This is proposed here: https://lore.kernel.org/dri-devel/20210520190007.534046-5-jason@jlekstrand.… These three pieces together allow userspace to fully control implicit fencing and remove all unecessary stall points due to them. Well, as much as the implicit fencing model fundamentally allows: There is only one set of fences, you can only choose to sync against only writers (exclusive slot), or everyone. Hence suballocating multiple buffers or anything else like this is fundamentally not possible, and can only be fixed by a proper explicit fencing model. Aside from that caveat this model gets implicit fencing as closely to explicit fencing semantics as possible: On the actual implementation I opted for a simple setparam ioctl, no locking (just atomic reads/writes) for simplicity. There is a nice flag parameter in the VM ioctl which we could use, except: - it's not checked, so userspace likely passes garbage - there's already a comment that userspace _does_ pass garbage in the priority field So yeah unfortunately this flag parameter for setting vm flags is useless, and we need to hack up a new one. v2: Explain why a new SETPARAM (Jason) v3: Bas noticed I forgot to hook up the dependency-side shortcut. We need both, or this doesn't do much. v4: Rebase over the amdgpu patch to always set the implicit sync fences. Cc: mesa-dev(a)lists.freedesktop.org Cc: Bas Nieuwenhuizen <bas(a)basnieuwenhuizen.nl> Cc: Dave Airlie <airlied(a)gmail.com> Cc: Rob Clark <robdclark(a)chromium.org> Cc: Kristian H. Kristensen <hoegsberg(a)google.com> Cc: Michel Dänzer <michel(a)daenzer.net> Cc: Daniel Stone <daniels(a)collabora.com> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: "Christian König" <christian.koenig(a)amd.com> Cc: Alex Deucher <alexander.deucher(a)amd.com> Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: Deepak R Varma <mh12gx2825(a)gmail.com> Cc: Chen Li <chenli(a)uniontech.com> Cc: Kevin Wang <kevin1.wang(a)amd.com> Cc: Dennis Li <Dennis.Li(a)amd.com> Cc: Luben Tuikov <luben.tuikov(a)amd.com> Cc: linaro-mm-sig(a)lists.linaro.org Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> --- drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 7 +++++-- drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 21 +++++++++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h | 6 ++++++ include/uapi/drm/amdgpu_drm.h | 10 ++++++++++ 4 files changed, 42 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c index 65df34c17264..c5386d13eb4a 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c @@ -498,6 +498,7 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p, struct amdgpu_bo *gds; struct amdgpu_bo *gws; struct amdgpu_bo *oa; + bool no_implicit_sync = READ_ONCE(fpriv->vm.no_implicit_sync); int r; INIT_LIST_HEAD(&p->validated); @@ -577,7 +578,8 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p, e->bo_va = amdgpu_vm_bo_find(vm, bo); - if (bo->tbo.base.dma_buf && !amdgpu_bo_explicit_sync(bo)) { + if (bo->tbo.base.dma_buf && + !(no_implicit_sync || amdgpu_bo_explicit_sync(bo))) { e->chain = dma_fence_chain_alloc(); if (!e->chain) { r = -ENOMEM; @@ -649,6 +651,7 @@ static int amdgpu_cs_sync_rings(struct amdgpu_cs_parser *p) { struct amdgpu_fpriv *fpriv = p->filp->driver_priv; struct amdgpu_bo_list_entry *e; + bool no_implicit_sync = READ_ONCE(fpriv->vm.no_implicit_sync); int r; list_for_each_entry(e, &p->validated, tv.head) { @@ -656,7 +659,7 @@ static int amdgpu_cs_sync_rings(struct amdgpu_cs_parser *p) struct dma_resv *resv = bo->tbo.base.resv; enum amdgpu_sync_mode sync_mode; - sync_mode = amdgpu_bo_explicit_sync(bo) ? + sync_mode = no_implicit_sync || amdgpu_bo_explicit_sync(bo) ? AMDGPU_SYNC_EXPLICIT : AMDGPU_SYNC_NE_OWNER; r = amdgpu_sync_resv(p->adev, &p->job->sync, resv, sync_mode, &fpriv->vm); diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c index c080ba15ae77..f982626b5328 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c @@ -1724,6 +1724,26 @@ int amdgpu_file_to_fpriv(struct file *filp, struct amdgpu_fpriv **fpriv) return 0; } +int amdgpu_setparam_ioctl(struct drm_device *dev, void *data, + struct drm_file *filp) +{ + struct drm_amdgpu_setparam *setparam = data; + struct amdgpu_fpriv *fpriv = filp->driver_priv; + + switch (setparam->param) { + case AMDGPU_SETPARAM_NO_IMPLICIT_SYNC: + if (setparam->value) + WRITE_ONCE(fpriv->vm.no_implicit_sync, true); + else + WRITE_ONCE(fpriv->vm.no_implicit_sync, false); + break; + default: + return -EINVAL; + } + + return 0; +} + const struct drm_ioctl_desc amdgpu_ioctls_kms[] = { DRM_IOCTL_DEF_DRV(AMDGPU_GEM_CREATE, amdgpu_gem_create_ioctl, DRM_AUTH|DRM_RENDER_ALLOW), DRM_IOCTL_DEF_DRV(AMDGPU_CTX, amdgpu_ctx_ioctl, DRM_AUTH|DRM_RENDER_ALLOW), @@ -1742,6 +1762,7 @@ const struct drm_ioctl_desc amdgpu_ioctls_kms[] = { DRM_IOCTL_DEF_DRV(AMDGPU_GEM_VA, amdgpu_gem_va_ioctl, DRM_AUTH|DRM_RENDER_ALLOW), DRM_IOCTL_DEF_DRV(AMDGPU_GEM_OP, amdgpu_gem_op_ioctl, DRM_AUTH|DRM_RENDER_ALLOW), DRM_IOCTL_DEF_DRV(AMDGPU_GEM_USERPTR, amdgpu_gem_userptr_ioctl, DRM_AUTH|DRM_RENDER_ALLOW), + DRM_IOCTL_DEF_DRV(AMDGPU_SETPARAM, amdgpu_setparam_ioctl, DRM_AUTH|DRM_RENDER_ALLOW), }; static const struct drm_driver amdgpu_kms_driver = { diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h index ddb85a85cbba..0e8c440c6303 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h @@ -321,6 +321,12 @@ struct amdgpu_vm { bool bulk_moveable; /* Flag to indicate if VM is used for compute */ bool is_compute_context; + /* + * Flag to indicate whether implicit sync should always be skipped on + * this context. We do not care about races at all, userspace is allowed + * to shoot itself with implicit sync to its fullest liking. + */ + bool no_implicit_sync; }; struct amdgpu_vm_manager { diff --git a/include/uapi/drm/amdgpu_drm.h b/include/uapi/drm/amdgpu_drm.h index 0cbd1540aeac..9eae245c14d6 100644 --- a/include/uapi/drm/amdgpu_drm.h +++ b/include/uapi/drm/amdgpu_drm.h @@ -54,6 +54,7 @@ extern "C" { #define DRM_AMDGPU_VM 0x13 #define DRM_AMDGPU_FENCE_TO_HANDLE 0x14 #define DRM_AMDGPU_SCHED 0x15 +#define DRM_AMDGPU_SETPARAM 0x16 #define DRM_IOCTL_AMDGPU_GEM_CREATE DRM_IOWR(DRM_COMMAND_BASE + DRM_AMDGPU_GEM_CREATE, union drm_amdgpu_gem_create) #define DRM_IOCTL_AMDGPU_GEM_MMAP DRM_IOWR(DRM_COMMAND_BASE + DRM_AMDGPU_GEM_MMAP, union drm_amdgpu_gem_mmap) @@ -71,6 +72,7 @@ extern "C" { #define DRM_IOCTL_AMDGPU_VM DRM_IOWR(DRM_COMMAND_BASE + DRM_AMDGPU_VM, union drm_amdgpu_vm) #define DRM_IOCTL_AMDGPU_FENCE_TO_HANDLE DRM_IOWR(DRM_COMMAND_BASE + DRM_AMDGPU_FENCE_TO_HANDLE, union drm_amdgpu_fence_to_handle) #define DRM_IOCTL_AMDGPU_SCHED DRM_IOW(DRM_COMMAND_BASE + DRM_AMDGPU_SCHED, union drm_amdgpu_sched) +#define DRM_IOCTL_AMDGPU_SETPARAM DRM_IOW(DRM_COMMAND_BASE + DRM_AMDGPU_SETPARAM, struct drm_amdgpu_setparam) /** * DOC: memory domains @@ -306,6 +308,14 @@ union drm_amdgpu_sched { struct drm_amdgpu_sched_in in; }; +#define AMDGPU_SETPARAM_NO_IMPLICIT_SYNC 1 + +struct drm_amdgpu_setparam { + /* AMDGPU_SETPARAM_* */ + __u32 param; + __u32 value; +}; + /* * This is not a reliable API and you should expect it to fail for any * number of reasons and have fallback path that do not use userptr to -- 2.32.0.rc2

3 years, 6 months

[PATCH 01/15] dma-resv: Fix kerneldoc

by Daniel Vetter

Oversight from commit 6edbd6abb783d54f6ac4c3ed5cd9e50cff6c15e9 Author: Christian König <christian.koenig(a)amd.com> Date: Mon May 10 16:14:09 2021 +0200 dma-buf: rename and cleanup dma_resv_get_excl v3 Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: "Christian König" <christian.koenig(a)amd.com> Cc: linux-media(a)vger.kernel.org Cc: linaro-mm-sig(a)lists.linaro.org --- include/linux/dma-resv.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h index 562b885cf9c3..e1ca2080a1ff 100644 --- a/include/linux/dma-resv.h +++ b/include/linux/dma-resv.h @@ -212,7 +212,7 @@ static inline void dma_resv_unlock(struct dma_resv *obj) } /** - * dma_resv_exclusive - return the object's exclusive fence + * dma_resv_excl_fence - return the object's exclusive fence * @obj: the reservation object * * Returns the exclusive fence (if any). Caller must either hold the objects -- 2.32.0.rc2

3 years, 6 months

Re: [Linaro-mm-sig] [PATCH v3 1/2] drm: add a locked version of drm_is_current_master

by Daniel Vetter

On Sun, Jun 20, 2021 at 07:03:26PM +0800, Desmond Cheong Zhi Xi wrote: > While checking the master status of the DRM file in > drm_is_current_master(), the device's master mutex should be > held. Without the mutex, the pointer fpriv->master may be freed > concurrently by another process calling drm_setmaster_ioctl(). This > could lead to use-after-free errors when the pointer is subsequently > dereferenced in drm_lease_owner(). > > The callers of drm_is_current_master() from drm_auth.c hold the > device's master mutex, but external callers do not. Hence, we implement > drm_is_current_master_locked() to be used within drm_auth.c, and > modify drm_is_current_master() to grab the device's master mutex > before checking the master status. > > Reported-by: Daniel Vetter <daniel.vetter(a)ffwll.ch> > Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx(a)gmail.com> > Reviewed-by: Emil Velikov <emil.l.velikov(a)gmail.com> Merged to drm-misc-fixes, thanks for your patch. -Daniel > --- > drivers/gpu/drm/drm_auth.c | 51 ++++++++++++++++++++++++-------------- > 1 file changed, 32 insertions(+), 19 deletions(-) > > diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c > index 232abbba3686..86d4b72e95cb 100644 > --- a/drivers/gpu/drm/drm_auth.c > +++ b/drivers/gpu/drm/drm_auth.c > @@ -61,6 +61,35 @@ > * trusted clients. > */ > > +static bool drm_is_current_master_locked(struct drm_file *fpriv) > +{ > + lockdep_assert_held_once(&fpriv->master->dev->master_mutex); > + > + return fpriv->is_master && drm_lease_owner(fpriv->master) == fpriv->minor->dev->master; > +} > + > +/** > + * drm_is_current_master - checks whether @priv is the current master > + * @fpriv: DRM file private > + * > + * Checks whether @fpriv is current master on its device. This decides whether a > + * client is allowed to run DRM_MASTER IOCTLs. > + * > + * Most of the modern IOCTL which require DRM_MASTER are for kernel modesetting > + * - the current master is assumed to own the non-shareable display hardware. > + */ > +bool drm_is_current_master(struct drm_file *fpriv) > +{ > + bool ret; > + > + mutex_lock(&fpriv->master->dev->master_mutex); > + ret = drm_is_current_master_locked(fpriv); > + mutex_unlock(&fpriv->master->dev->master_mutex); > + > + return ret; > +} > +EXPORT_SYMBOL(drm_is_current_master); > + > int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv) > { > struct drm_auth *auth = data; > @@ -223,7 +252,7 @@ int drm_setmaster_ioctl(struct drm_device *dev, void *data, > if (ret) > goto out_unlock; > > - if (drm_is_current_master(file_priv)) > + if (drm_is_current_master_locked(file_priv)) > goto out_unlock; > > if (dev->master) { > @@ -272,7 +301,7 @@ int drm_dropmaster_ioctl(struct drm_device *dev, void *data, > if (ret) > goto out_unlock; > > - if (!drm_is_current_master(file_priv)) { > + if (!drm_is_current_master_locked(file_priv)) { > ret = -EINVAL; > goto out_unlock; > } > @@ -321,7 +350,7 @@ void drm_master_release(struct drm_file *file_priv) > if (file_priv->magic) > idr_remove(&file_priv->master->magic_map, file_priv->magic); > > - if (!drm_is_current_master(file_priv)) > + if (!drm_is_current_master_locked(file_priv)) > goto out; > > drm_legacy_lock_master_cleanup(dev, master); > @@ -342,22 +371,6 @@ void drm_master_release(struct drm_file *file_priv) > mutex_unlock(&dev->master_mutex); > } > > -/** > - * drm_is_current_master - checks whether @priv is the current master > - * @fpriv: DRM file private > - * > - * Checks whether @fpriv is current master on its device. This decides whether a > - * client is allowed to run DRM_MASTER IOCTLs. > - * > - * Most of the modern IOCTL which require DRM_MASTER are for kernel modesetting > - * - the current master is assumed to own the non-shareable display hardware. > - */ > -bool drm_is_current_master(struct drm_file *fpriv) > -{ > - return fpriv->is_master && drm_lease_owner(fpriv->master) == fpriv->minor->dev->master; > -} > -EXPORT_SYMBOL(drm_is_current_master); > - > /** > * drm_master_get - reference a master pointer > * @master: &struct drm_master > -- > 2.25.1 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch

3 years, 6 months

Re: [Linaro-mm-sig] [PATCH v3 2/2] drm: protect drm_master pointers in drm_lease.c

by Daniel Vetter

On Wed, Jun 23, 2021 at 5:49 AM Desmond Cheong Zhi Xi <desmondcheongzx(a)gmail.com> wrote: > > On 21/6/21 10:47 pm, Daniel Vetter wrote: > > On Sun, Jun 20, 2021 at 07:03:27PM +0800, Desmond Cheong Zhi Xi wrote: > >> diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c > >> index 86d4b72e95cb..0c64a77c67a6 100644 > >> --- a/drivers/gpu/drm/drm_auth.c > >> +++ b/drivers/gpu/drm/drm_auth.c > >> @@ -384,6 +384,28 @@ struct drm_master *drm_master_get(struct drm_master *master) > >> } > >> EXPORT_SYMBOL(drm_master_get); > >> > >> +/** > >> + * drm_file_get_master - reference @file_priv->master > >> + * @file_priv: DRM file private > >> + * > >> + * Increments the reference count of @file_priv->master and returns > > > > Does this format correctly? I'd go with "&drm_file.master of @file_priv". > > > > Got it. "file_priv->master" was bolded, but no link to drm_file.master > was generated. I'll update this. > > >> + * @file_priv->master. > >> + * > >> + * Master pointers returned from this function should be unreferenced using > >> + * drm_master_put(). > >> + */ > >> +struct drm_master *drm_file_get_master(struct drm_file *file_priv) > >> +{ > >> + struct drm_master *master; > >> + > >> + mutex_lock(&file_priv->master->dev->master_mutex); > >> + master = drm_master_get(file_priv->master); > >> + mutex_unlock(&file_priv->master->dev->master_mutex); > >> + > >> + return master; > >> +} > >> +EXPORT_SYMBOL(drm_file_get_master); > >> + > >> static void drm_master_destroy(struct kref *kref) > >> { > >> struct drm_master *master = container_of(kref, struct drm_master, refcount); > >> diff --git a/drivers/gpu/drm/drm_lease.c b/drivers/gpu/drm/drm_lease.c > >> index da4f085fc09e..65eab82f8acc 100644 > >> --- a/drivers/gpu/drm/drm_lease.c > >> +++ b/drivers/gpu/drm/drm_lease.c > >> @@ -107,10 +107,17 @@ static bool _drm_has_leased(struct drm_master *master, int id) > >> */ > >> bool _drm_lease_held(struct drm_file *file_priv, int id) > >> { > >> + bool ret; > >> + struct drm_master *master; > >> + > >> if (!file_priv || !file_priv->master) > > > > So here we still have a ->master access outside of the locked code > > section. I think the best fix for that would be to move the NULL check > > into drm_file_get_master (where we grab the lock already anyway), and > > update the kerneldoc to state that it might return NULL. > > > > Same with all the checks for ->master below. > > > > Moving the check into drm_file_get_master sounds good. Grabbing the lock > before performing the NULL check poses a little chicken-and-egg problem > though. > > It's true that without the lock, even if file_priv->master passes the > NULL check, it could be freed in the time between the check and grabbing > the lock. > > However, based on the original code, it seems there's the possibility > that file_priv->master might be NULL. In this case, grabbing the lock > results in a null ptr dereference because we get the mutex via > &file_priv->master->dev->master_mutex. > > By this reasoning, I think the safer method is still to perform the NULL > check before grabbing the lock. file_priv->dev->master_mutex should also work and avoid the trouble. Please also cc intel-gfx list, there's a CI system there to test your patches. Since patch 1 of this series had pretty bad deadlock that I didn't see would be good to make sure we get more test coverage on these. Thanks, Daniel > > >> return true; > >> > >> - return _drm_lease_held_master(file_priv->master, id); > >> + master = drm_file_get_master(file_priv); > >> + ret = _drm_lease_held_master(master, id); > >> + drm_master_put(&master); > >> + > >> + return ret; > >> } > >> > >> /** > >> @@ -132,10 +139,11 @@ bool drm_lease_held(struct drm_file *file_priv, int id) > >> if (!file_priv || !file_priv->master || !file_priv->master->lessor) > >> return true; > > > > master->lessor dereferenced outside the lock or without holding a > > reference. > > > >> > >> - master = file_priv->master; > >> + master = drm_file_get_master(file_priv); > >> mutex_lock(&master->dev->mode_config.idr_mutex); > >> ret = _drm_lease_held_master(master, id); > >> mutex_unlock(&master->dev->mode_config.idr_mutex); > >> + drm_master_put(&master); > >> return ret; > >> } > >> > >> @@ -158,7 +166,7 @@ uint32_t drm_lease_filter_crtcs(struct drm_file *file_priv, uint32_t crtcs_in) > >> if (!file_priv || !file_priv->master || !file_priv->master->lessor) > >> return crtcs_in; > > > > Same here. > > > >> > >> - master = file_priv->master; > >> + master = drm_file_get_master(file_priv); > >> dev = master->dev; > >> > >> count_in = count_out = 0; > >> @@ -177,6 +185,7 @@ uint32_t drm_lease_filter_crtcs(struct drm_file *file_priv, uint32_t crtcs_in) > >> count_in++; > >> } > >> mutex_unlock(&master->dev->mode_config.idr_mutex); > >> + drm_master_put(&master); > >> return crtcs_out; > >> } > >> > >> @@ -490,7 +499,7 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev, > >> size_t object_count; > >> int ret = 0; > >> struct idr leases; > >> - struct drm_master *lessor = lessor_priv->master; > >> + struct drm_master *lessor; > >> struct drm_master *lessee = NULL; > >> struct file *lessee_file = NULL; > >> struct file *lessor_file = lessor_priv->filp; > >> @@ -502,12 +511,6 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev, > >> if (!drm_core_check_feature(dev, DRIVER_MODESET)) > >> return -EOPNOTSUPP; > >> > >> - /* Do not allow sub-leases */ > >> - if (lessor->lessor) { > >> - DRM_DEBUG_LEASE("recursive leasing not allowed\n"); > >> - return -EINVAL; > >> - } > >> - > >> /* need some objects */ > >> if (cl->object_count == 0) { > >> DRM_DEBUG_LEASE("no objects in lease\n"); > >> @@ -519,12 +522,22 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev, > >> return -EINVAL; > >> } > >> > >> + lessor = drm_file_get_master(lessor_priv); > >> + /* Do not allow sub-leases */ > >> + if (lessor->lessor) { > > > > Here we check after grabbing the reference, so looks correct. > > > >> + DRM_DEBUG_LEASE("recursive leasing not allowed\n"); > >> + ret = -EINVAL; > >> + goto out_lessor; > >> + } > >> + > >> object_count = cl->object_count; > >> > >> object_ids = memdup_user(u64_to_user_ptr(cl->object_ids), > >> array_size(object_count, sizeof(__u32))); > >> - if (IS_ERR(object_ids)) > >> - return PTR_ERR(object_ids); > >> + if (IS_ERR(object_ids)) { > >> + ret = PTR_ERR(object_ids); > >> + goto out_lessor; > >> + } > >> > >> idr_init(&leases); > >> > >> @@ -535,14 +548,15 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev, > >> if (ret) { > >> DRM_DEBUG_LEASE("lease object lookup failed: %i\n", ret); > >> idr_destroy(&leases); > >> - return ret; > >> + goto out_lessor; > >> } > >> > >> /* Allocate a file descriptor for the lease */ > >> fd = get_unused_fd_flags(cl->flags & (O_CLOEXEC | O_NONBLOCK)); > >> if (fd < 0) { > >> idr_destroy(&leases); > >> - return fd; > >> + ret = fd; > >> + goto out_lessor; > >> } > >> > >> DRM_DEBUG_LEASE("Creating lease\n"); > >> @@ -578,6 +592,7 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev, > >> /* Hook up the fd */ > >> fd_install(fd, lessee_file); > >> > >> + drm_master_put(&lessor); > >> DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl succeeded\n"); > >> return 0; > >> > >> @@ -587,6 +602,8 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev, > >> out_leases: > >> put_unused_fd(fd); > >> > >> +out_lessor: > >> + drm_master_put(&lessor); > >> DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl failed: %d\n", ret); > >> return ret; > >> } > >> @@ -609,7 +626,7 @@ int drm_mode_list_lessees_ioctl(struct drm_device *dev, > >> struct drm_mode_list_lessees *arg = data; > >> __u32 __user *lessee_ids = (__u32 __user *) (uintptr_t) (arg->lessees_ptr); > >> __u32 count_lessees = arg->count_lessees; > >> - struct drm_master *lessor = lessor_priv->master, *lessee; > >> + struct drm_master *lessor, *lessee; > >> int count; > >> int ret = 0; > >> > >> @@ -620,6 +637,7 @@ int drm_mode_list_lessees_ioctl(struct drm_device *dev, > >> if (!drm_core_check_feature(dev, DRIVER_MODESET)) > >> return -EOPNOTSUPP; > >> > >> + lessor = drm_file_get_master(lessor_priv); > >> DRM_DEBUG_LEASE("List lessees for %d\n", lessor->lessee_id); > >> > >> mutex_lock(&dev->mode_config.idr_mutex); > >> @@ -643,6 +661,7 @@ int drm_mode_list_lessees_ioctl(struct drm_device *dev, > >> arg->count_lessees = count; > >> > >> mutex_unlock(&dev->mode_config.idr_mutex); > >> + drm_master_put(&lessor); > >> > >> return ret; > >> } > >> @@ -662,7 +681,7 @@ int drm_mode_get_lease_ioctl(struct drm_device *dev, > >> struct drm_mode_get_lease *arg = data; > >> __u32 __user *object_ids = (__u32 __user *) (uintptr_t) (arg->objects_ptr); > >> __u32 count_objects = arg->count_objects; > >> - struct drm_master *lessee = lessee_priv->master; > >> + struct drm_master *lessee; > >> struct idr *object_idr; > >> int count; > >> void *entry; > >> @@ -676,6 +695,7 @@ int drm_mode_get_lease_ioctl(struct drm_device *dev, > >> if (!drm_core_check_feature(dev, DRIVER_MODESET)) > >> return -EOPNOTSUPP; > >> > >> + lessee = drm_file_get_master(lessee_priv); > >> DRM_DEBUG_LEASE("get lease for %d\n", lessee->lessee_id); > >> > >> mutex_lock(&dev->mode_config.idr_mutex); > >> @@ -703,6 +723,7 @@ int drm_mode_get_lease_ioctl(struct drm_device *dev, > >> arg->count_objects = count; > >> > >> mutex_unlock(&dev->mode_config.idr_mutex); > >> + drm_master_put(&lessee); > >> > >> return ret; > >> } > >> @@ -721,7 +742,7 @@ int drm_mode_revoke_lease_ioctl(struct drm_device *dev, > >> void *data, struct drm_file *lessor_priv) > >> { > >> struct drm_mode_revoke_lease *arg = data; > >> - struct drm_master *lessor = lessor_priv->master; > >> + struct drm_master *lessor; > >> struct drm_master *lessee; > >> int ret = 0; > >> > >> @@ -731,6 +752,7 @@ int drm_mode_revoke_lease_ioctl(struct drm_device *dev, > >> if (!drm_core_check_feature(dev, DRIVER_MODESET)) > >> return -EOPNOTSUPP; > >> > >> + lessor = drm_file_get_master(lessor_priv); > >> mutex_lock(&dev->mode_config.idr_mutex); > >> > >> lessee = _drm_find_lessee(lessor, arg->lessee_id); > >> @@ -751,6 +773,7 @@ int drm_mode_revoke_lease_ioctl(struct drm_device *dev, > >> > >> fail: > >> mutex_unlock(&dev->mode_config.idr_mutex); > >> + drm_master_put(&lessor); > >> > >> return ret; > >> } > >> diff --git a/include/drm/drm_auth.h b/include/drm/drm_auth.h > >> index 6bf8b2b78991..f99d3417f304 100644 > >> --- a/include/drm/drm_auth.h > >> +++ b/include/drm/drm_auth.h > >> @@ -107,6 +107,7 @@ struct drm_master { > >> }; > >> > >> struct drm_master *drm_master_get(struct drm_master *master); > >> +struct drm_master *drm_file_get_master(struct drm_file *file_priv); > >> void drm_master_put(struct drm_master **master); > >> bool drm_is_current_master(struct drm_file *fpriv); > >> > >> diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h > >> index b81b3bfb08c8..e9931fca4ab7 100644 > >> --- a/include/drm/drm_file.h > >> +++ b/include/drm/drm_file.h > >> @@ -226,9 +226,18 @@ struct drm_file { > >> /** > >> * @master: > >> * > >> - * Master this node is currently associated with. Only relevant if > >> - * drm_is_primary_client() returns true. Note that this only > >> - * matches &drm_device.master if the master is the currently active one. > >> + * Master this node is currently associated with. Protected by struct > >> + * &drm_device.master_mutex. > >> + * > >> + * Only relevant if drm_is_primary_client() returns true. Note that > >> + * this only matches &drm_device.master if the master is the currently > >> + * active one. > >> + * > >> + * When obtaining a copy of this pointer, it is recommended to either > >> + * hold struct &drm_device.master_mutex for the duration of the > >> + * pointer's use, or to use drm_file_get_master() if struct > >> + * &drm_device.master_mutex is not currently held and there is no other > >> + * need to hold it. This prevents @master from being freed during use. > >> * > >> * See also @authentication and @is_master and the :ref:`section on > >> * primary nodes and authentication <drm_primary_node>`. > >> -- > >> 2.25.1 > >> > > > > Thanks for the feedback, Daniel. I'll send out an updated patch to > address these issues. > > Best wishes, > Desmond -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch

3 years, 6 months

[PATCH 06/15] drm/panfrost: Fix implicit sync

by Daniel Vetter

Currently this has no practial relevance I think because there's not many who can pull off a setup with panfrost and another gpu in the same system. But the rules are that if you're setting an exclusive fence, indicating a gpu write access in the implicit fencing system, then you need to wait for all fences, not just the previous exclusive fence. panfrost against itself has no problem, because it always sets the exclusive fence (but that's probably something that will need to be fixed for vulkan and/or multi-engine gpus, or you'll suffer badly). Also no problem with that against display. With the prep work done to switch over to the dependency helpers this is now a oneliner. Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> Cc: Rob Herring <robh(a)kernel.org> Cc: Tomeu Vizoso <tomeu.vizoso(a)collabora.com> Cc: Steven Price <steven.price(a)arm.com> Cc: Alyssa Rosenzweig <alyssa.rosenzweig(a)collabora.com> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: "Christian König" <christian.koenig(a)amd.com> Cc: linux-media(a)vger.kernel.org Cc: linaro-mm-sig(a)lists.linaro.org --- drivers/gpu/drm/panfrost/panfrost_job.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c index 71cd43fa1b36..ef004d587dc4 100644 --- a/drivers/gpu/drm/panfrost/panfrost_job.c +++ b/drivers/gpu/drm/panfrost/panfrost_job.c @@ -203,9 +203,8 @@ static int panfrost_acquire_object_fences(struct drm_gem_object **bos, int i, ret; for (i = 0; i < bo_count; i++) { - struct dma_fence *fence = dma_resv_get_excl_unlocked(bos[i]->resv); - - ret = drm_gem_fence_array_add(deps, fence); + /* panfrost always uses write mode in its current uapi */ + ret = drm_gem_fence_array_add_implicit(deps, bos[i], true); if (ret) return ret; } -- 2.32.0.rc2

3 years, 6 months

[PATCH 05/15] drm/panfrost: Use xarray and helpers for depedency tracking

by Daniel Vetter

More consistency and prep work for the next patch. Aside: I wonder whether we shouldn't just move this entire xarray business into the scheduler so that not everyone has to reinvent the same wheels. Cc'ing some scheduler people for this too. v2: Correctly handle sched_lock since Lucas pointed out it's needed. v3: Rebase, dma_resv_get_excl_unlocked got renamed v4: Don't leak job references on failure (Steven). Cc: Lucas Stach <l.stach(a)pengutronix.de> Cc: "Christian König" <christian.koenig(a)amd.com> Cc: Luben Tuikov <luben.tuikov(a)amd.com> Cc: Alex Deucher <alexander.deucher(a)amd.com> Cc: Lee Jones <lee.jones(a)linaro.org> Cc: Steven Price <steven.price(a)arm.com> Cc: Rob Herring <robh(a)kernel.org> Cc: Tomeu Vizoso <tomeu.vizoso(a)collabora.com> Cc: Alyssa Rosenzweig <alyssa.rosenzweig(a)collabora.com> Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: linux-media(a)vger.kernel.org Cc: linaro-mm-sig(a)lists.linaro.org Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com> --- drivers/gpu/drm/panfrost/panfrost_drv.c | 41 +++++++--------- drivers/gpu/drm/panfrost/panfrost_job.c | 65 +++++++++++-------------- drivers/gpu/drm/panfrost/panfrost_job.h | 8 ++- 3 files changed, 49 insertions(+), 65 deletions(-) diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c index 075ec0ef746c..3ee828f1e7a5 100644 --- a/drivers/gpu/drm/panfrost/panfrost_drv.c +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c @@ -138,12 +138,6 @@ panfrost_lookup_bos(struct drm_device *dev, if (!job->bo_count) return 0; - job->implicit_fences = kvmalloc_array(job->bo_count, - sizeof(struct dma_fence *), - GFP_KERNEL | __GFP_ZERO); - if (!job->implicit_fences) - return -ENOMEM; - ret = drm_gem_objects_lookup(file_priv, (void __user *)(uintptr_t)args->bo_handles, job->bo_count, &job->bos); @@ -174,7 +168,7 @@ panfrost_lookup_bos(struct drm_device *dev, } /** - * panfrost_copy_in_sync() - Sets up job->in_fences[] with the sync objects + * panfrost_copy_in_sync() - Sets up job->deps with the sync objects * referenced by the job. * @dev: DRM device * @file_priv: DRM file for this fd @@ -194,22 +188,14 @@ panfrost_copy_in_sync(struct drm_device *dev, { u32 *handles; int ret = 0; - int i; + int i, in_fence_count; - job->in_fence_count = args->in_sync_count; + in_fence_count = args->in_sync_count; - if (!job->in_fence_count) + if (!in_fence_count) return 0; - job->in_fences = kvmalloc_array(job->in_fence_count, - sizeof(struct dma_fence *), - GFP_KERNEL | __GFP_ZERO); - if (!job->in_fences) { - DRM_DEBUG("Failed to allocate job in fences\n"); - return -ENOMEM; - } - - handles = kvmalloc_array(job->in_fence_count, sizeof(u32), GFP_KERNEL); + handles = kvmalloc_array(in_fence_count, sizeof(u32), GFP_KERNEL); if (!handles) { ret = -ENOMEM; DRM_DEBUG("Failed to allocate incoming syncobj handles\n"); @@ -218,16 +204,23 @@ panfrost_copy_in_sync(struct drm_device *dev, if (copy_from_user(handles, (void __user *)(uintptr_t)args->in_syncs, - job->in_fence_count * sizeof(u32))) { + in_fence_count * sizeof(u32))) { ret = -EFAULT; DRM_DEBUG("Failed to copy in syncobj handles\n"); goto fail; } - for (i = 0; i < job->in_fence_count; i++) { + for (i = 0; i < in_fence_count; i++) { + struct dma_fence *fence; + ret = drm_syncobj_find_fence(file_priv, handles[i], 0, 0, - &job->in_fences[i]); - if (ret == -EINVAL) + &fence); + if (ret) + goto fail; + + ret = drm_gem_fence_array_add(&job->deps, fence); + + if (ret) goto fail; } @@ -265,6 +258,8 @@ static int panfrost_ioctl_submit(struct drm_device *dev, void *data, kref_init(&job->refcount); + xa_init_flags(&job->deps, XA_FLAGS_ALLOC); + job->pfdev = pfdev; job->jc = args->jc; job->requirements = args->requirements; diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c index 38f8580c19f1..71cd43fa1b36 100644 --- a/drivers/gpu/drm/panfrost/panfrost_job.c +++ b/drivers/gpu/drm/panfrost/panfrost_job.c @@ -196,14 +196,21 @@ static void panfrost_job_hw_submit(struct panfrost_job *job, int js) job_write(pfdev, JS_COMMAND_NEXT(js), JS_COMMAND_START); } -static void panfrost_acquire_object_fences(struct drm_gem_object **bos, - int bo_count, - struct dma_fence **implicit_fences) +static int panfrost_acquire_object_fences(struct drm_gem_object **bos, + int bo_count, + struct xarray *deps) { - int i; + int i, ret; - for (i = 0; i < bo_count; i++) - implicit_fences[i] = dma_resv_get_excl_unlocked(bos[i]->resv); + for (i = 0; i < bo_count; i++) { + struct dma_fence *fence = dma_resv_get_excl_unlocked(bos[i]->resv); + + ret = drm_gem_fence_array_add(deps, fence); + if (ret) + return ret; + } + + return 0; } static void panfrost_attach_object_fences(struct drm_gem_object **bos, @@ -240,10 +247,14 @@ int panfrost_job_push(struct panfrost_job *job) job->render_done_fence = dma_fence_get(&job->base.s_fence->finished); - kref_get(&job->refcount); /* put by scheduler job completion */ + ret = panfrost_acquire_object_fences(job->bos, job->bo_count, + &job->deps); + if (ret) { + mutex_unlock(&pfdev->sched_lock); + goto unlock; + } - panfrost_acquire_object_fences(job->bos, job->bo_count, - job->implicit_fences); + kref_get(&job->refcount); /* put by scheduler job completion */ drm_sched_entity_push_job(&job->base, entity); @@ -262,18 +273,15 @@ static void panfrost_job_cleanup(struct kref *ref) { struct panfrost_job *job = container_of(ref, struct panfrost_job, refcount); + struct dma_fence *fence; + unsigned long index; unsigned int i; - if (job->in_fences) { - for (i = 0; i < job->in_fence_count; i++) - dma_fence_put(job->in_fences[i]); - kvfree(job->in_fences); - } - if (job->implicit_fences) { - for (i = 0; i < job->bo_count; i++) - dma_fence_put(job->implicit_fences[i]); - kvfree(job->implicit_fences); + xa_for_each(&job->deps, index, fence) { + dma_fence_put(fence); } + xa_destroy(&job->deps); + dma_fence_put(job->done_fence); dma_fence_put(job->render_done_fence); @@ -316,26 +324,9 @@ static struct dma_fence *panfrost_job_dependency(struct drm_sched_job *sched_job struct drm_sched_entity *s_entity) { struct panfrost_job *job = to_panfrost_job(sched_job); - struct dma_fence *fence; - unsigned int i; - - /* Explicit fences */ - for (i = 0; i < job->in_fence_count; i++) { - if (job->in_fences[i]) { - fence = job->in_fences[i]; - job->in_fences[i] = NULL; - return fence; - } - } - /* Implicit fences, max. one per BO */ - for (i = 0; i < job->bo_count; i++) { - if (job->implicit_fences[i]) { - fence = job->implicit_fences[i]; - job->implicit_fences[i] = NULL; - return fence; - } - } + if (!xa_empty(&job->deps)) + return xa_erase(&job->deps, job->last_dep++); return NULL; } diff --git a/drivers/gpu/drm/panfrost/panfrost_job.h b/drivers/gpu/drm/panfrost/panfrost_job.h index bbd3ba97ff67..82306a03b57e 100644 --- a/drivers/gpu/drm/panfrost/panfrost_job.h +++ b/drivers/gpu/drm/panfrost/panfrost_job.h @@ -19,9 +19,9 @@ struct panfrost_job { struct panfrost_device *pfdev; struct panfrost_file_priv *file_priv; - /* Optional fences userspace can pass in for the job to depend on. */ - struct dma_fence **in_fences; - u32 in_fence_count; + /* Contains both explicit and implicit fences */ + struct xarray deps; + unsigned long last_dep; /* Fence to be signaled by IRQ handler when the job is complete. */ struct dma_fence *done_fence; @@ -30,8 +30,6 @@ struct panfrost_job { __u32 requirements; __u32 flush_id; - /* Exclusive fences we have taken from the BOs to wait for */ - struct dma_fence **implicit_fences; struct panfrost_gem_mapping **mappings; struct drm_gem_object **bos; u32 bo_count; -- 2.32.0.rc2

3 years, 6 months

Re: [Linaro-mm-sig] [PATCH v3 1/2] habanalabs: define uAPI to export FD for DMA-BUF

by Christian König

Am 22.06.21 um 17:40 schrieb Oded Gabbay: > On Tue, Jun 22, 2021 at 6:31 PM Christian König > <christian.koenig(a)amd.com> wrote: >> >> >> Am 22.06.21 um 17:28 schrieb Jason Gunthorpe: >>> On Tue, Jun 22, 2021 at 05:24:08PM +0200, Christian König wrote: >>> >>>>>> I will take two GAUDI devices and use one as an exporter and one as an >>>>>> importer. I want to see that the solution works end-to-end, with real >>>>>> device DMA from importer to exporter. >>>>> I can tell you it doesn't. Stuffing physical addresses directly into >>>>> the sg list doesn't involve any of the IOMMU code so any configuration >>>>> that requires IOMMU page table setup will not work. >>>> Sure it does. See amdgpu_vram_mgr_alloc_sgt: >>>> >>>> amdgpu_res_first(res, offset, length, &cursor); >>> ^^^^^^^^^^ >>> >>> I'm not talking about the AMD driver, I'm talking about this patch. >>> >>> + bar_address = hdev->dram_pci_bar_start + >>> + (pages[cur_page] - prop->dram_base_address); >>> + sg_dma_address(sg) = bar_address; >> Yeah, that is indeed not working. >> >> Oded you need to use dma_map_resource() for this. >> >> Christian. > Yes, of course. > But will it be enough ? > Jason said that supporting IOMMU isn't nice when we don't have struct pages. > I fail to understand the connection, I need to dig into this. Question is what you want to do with this? A struct page is always needed if you want to do stuff like HMM with it, if you only want P2P between device I actually recommend to avoid it. Christian. > > Oded > >> >> >>> Jason

3 years, 6 months

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