Linaro-mm-sig

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3497 discussions

Re: [PATCH] udmabuf: add CONFIG_MMU dependency

by David Hildenbrand

Am 28.05.24 um 15:31 schrieb Arnd Bergmann: > From: Arnd Bergmann <arnd(a)arndb.de> > > There is no !CONFIG_MMU version of vmf_insert_pfn(): > > arm-linux-gnueabi-ld: drivers/dma-buf/udmabuf.o: in function `udmabuf_vm_fault': > udmabuf.c:(.text+0xaa): undefined reference to `vmf_insert_pfn' > > Fixes: f7254e043ff1 ("udmabuf: use vmf_insert_pfn and VM_PFNMAP for handling mmap") > Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> > --- > drivers/dma-buf/Kconfig | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig > index e4dc53a36428..b46eb8a552d7 100644 > --- a/drivers/dma-buf/Kconfig > +++ b/drivers/dma-buf/Kconfig > @@ -35,6 +35,7 @@ config UDMABUF > default n > depends on DMA_SHARED_BUFFER > depends on MEMFD_CREATE || COMPILE_TEST > + depends on MMU > help > A driver to let userspace turn memfd regions into dma-bufs. > Qemu can use this to create host dmabufs for guest framebuffers. Acked-by: David Hildenbrand <david(a)redhat.com> -- Thanks, David / dhildenb

1 year, 8 months

Re: [PATCH v4 1/3] dt-bindings: mailbox: Add mediatek,gce-props.yaml

by AngeloGioacchino Del Regno

Il 26/05/24 17:04, Jason-JH Lin (林睿祥) ha scritto: > Hi Angelo, Jassi, > > Could you help me apply this series? > Thanks! > That's not me, it's Jassi - green light from me, btw. Cheers, Angelo > Regards, > Jason-JH.Lin > > On Wed, 2024-01-24 at 09:57 +0100, AngeloGioacchino Del Regno wrote: >> Il 24/01/24 02:14, Jason-JH.Lin ha scritto: >>> Add mediatek,gce-props.yaml for common GCE properties that is used >>> for >>> both mailbox providers and consumers. We place the common property >>> "mediatek,gce-events" in this binding currently. >>> >>> The property "mediatek,gce-events" is used for GCE event ID >>> corresponding >>> to a hardware event signal sent by the hardware or a software >>> driver. >>> If the mailbox providers or consumers want to manipulate the value >>> of >>> the event ID, they need to know the specific event ID. >>> >>> Signed-off-by: Jason-JH.Lin <jason-jh.lin(a)mediatek.com> >>> Reviewed-by: Conor Dooley <conor.dooley(a)microchip.com> >> >> Reviewed-by: AngeloGioacchino Del Regno < >> angelogioacchino.delregno(a)collabora.com> >> >

1 year, 8 months

Re: [PATCH v2] dma-buf: handle testing kthreads creation failure

by T.J. Mercier

On Wed, May 22, 2024 at 11:14 AM Fedor Pchelkin <pchelkin(a)ispras.ru> wrote: > > kthread creation may possibly fail inside race_signal_callback(). In > such a case stop the already started threads, put the already taken > references to them and return with error code. > > Found by Linux Verification Center (linuxtesting.org). > > Fixes: 2989f6451084 ("dma-buf: Add selftests for dma-fence") > Cc: stable(a)vger.kernel.org > Signed-off-by: Fedor Pchelkin <pchelkin(a)ispras.ru> Reviewed-by: T.J. Mercier <tjmercier(a)google.com> > --- > v2: use kthread_stop_put() to actually put the last reference as > T.J. Mercier noticed; > link to v1: https://lore.kernel.org/lkml/20240522122326.696928-1-pchelkin@ispras.ru/ > > drivers/dma-buf/st-dma-fence.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/dma-buf/st-dma-fence.c b/drivers/dma-buf/st-dma-fence.c > index b7c6f7ea9e0c..6a1bfcd0cc21 100644 > --- a/drivers/dma-buf/st-dma-fence.c > +++ b/drivers/dma-buf/st-dma-fence.c > @@ -540,6 +540,12 @@ static int race_signal_callback(void *arg) > t[i].before = pass; > t[i].task = kthread_run(thread_signal_callback, &t[i], > "dma-fence:%d", i); > + if (IS_ERR(t[i].task)) { > + ret = PTR_ERR(t[i].task); > + while (--i >= 0) > + kthread_stop_put(t[i].task); > + return ret; > + } > get_task_struct(t[i].task); > } > > -- > 2.39.2 >

1 year, 9 months

[PATCH v6 0/7] Add mediate-drm secure flow for SVP

by Jason-JH.Lin

From: Jason-jh Lin <jason-jh.lin(a)mediatek.corp-partner.google.com> Memory Definitions: secure memory - Memory allocated in the TEE (Trusted Execution Environment) which is inaccessible in the REE (Rich Execution Environment, i.e. linux kernel/userspace). secure handle - Integer value which acts as reference to 'secure memory'. Used in communication between TEE and REE to reference 'secure memory'. secure buffer - 'secure memory' that is used to store decrypted, compressed video or for other general purposes in the TEE. secure surface - 'secure memory' that is used to store graphic buffers. Memory Usage in SVP: The overall flow of SVP starts with encrypted video coming in from an outside source into the REE. The REE will then allocate a 'secure buffer' and send the corresponding 'secure handle' along with the encrypted, compressed video data to the TEE. The TEE will then decrypt the video and store the result in the 'secure buffer'. The REE will then allocate a 'secure surface'. The REE will pass the 'secure handles' for both the 'secure buffer' and 'secure surface' into the TEE for video decoding. The video decoder HW will then decode the contents of the 'secure buffer' and place the result in the 'secure surface'. The REE will then attach the 'secure surface' to the overlay plane for rendering of the video. Everything relating to ensuring security of the actual contents of the 'secure buffer' and 'secure surface' is out of scope for the REE and is the responsibility of the TEE. DRM driver handles allocation of gem objects that are backed by a 'secure surface' and for displaying a 'secure surface' on the overlay plane. This introduces a new flag for object creation called DRM_MTK_GEM_CREATE_RESTRICTED which indicates it should be a 'secure surface'. All changes here are in MediaTek specific code. --- TODO: 1) Drop MTK_DRM_IOCTL_GEM_CREATE and use DMA_HEAP_IOCTL_ALLOC in userspace 2) DRM driver use secure mailbox channel to handle normal and secure flow 3) Implement setting mmsys routing table in the secure world series --- Based on 3 series: [1] v3 dma-buf: heaps: Add MediaTek secure heap - https://patchwork.kernel.org/project/linux-mediatek/list/?series=809023 [2] v6 media: mediatek: add driver to support secure video decoder - https://patchwork.kernel.org/project/linux-mediatek/list/?series=853689 [3] v6 Add CMDQ secure driver for SVP - https://patchwork.kernel.org/project/linux-mediatek/list/?series=855884 --- Change in v6: 1. Rebase to linux-next then rebased on 3 series [1][2][3] 2. Remove some parameter and security settings in normal world 3. Drop secure port related patches 4. Fix some build error and warning Changes in v5: 1. Sync the local changes Changes in v4: 1. Rebase on mediatek-drm-next(278640d4d74cd) and fix the conflicts 2. This series is based on 20240129063025.29251-1-yunfei.dong(a)mediatek.com 3. This series is based on 20240322052829.9893-1-shawn.sung(a)mediatek.com 4. This series is based on 20240403065603.21920-1-shawn.sung(a)mediatek.com Changes in v3: 1. fix kerneldoc problems 2. fix typo in title and commit message 3. adjust naming for secure variable 4. add the missing part for is_suecure plane implementation 5. use BIT_ULL macro to replace bit shifting 6. move modification of ovl_adaptor part to the correct patch 7. add TODO list in commit message 8. add commit message for using share memory to store execute count Changes in v2: 1. remove the DRIVER_RDNDER flag for mtk_drm_ioctl 2. move cmdq_insert_backup_cookie into client driver 3. move secure gce node define from mt8195-cherry.dtsi to mt8195.dtsi --- CK Hu (1): drm/mediatek: Add interface to allocate MediaTek GEM buffer Jason-JH.Lin (6): drm/mediatek/uapi: Add DRM_MTK_GEM_CREATE_RESTRICTED flag drm/mediatek: Add secure buffer control flow to mtk_drm_gem drm/mediatek: Add secure identify flag and funcution to mtk_drm_plane drm/mediatek: Add mtk_ddp_sec_write() to config secure buffer info drm/mediatek: Add secure flow support to mediatek-drm drm/mediatek: Add cmdq_insert_backup_cookie before secure pkt finalize drivers/gpu/drm/mediatek/mtk_crtc.c | 263 +++++++++++++++++- drivers/gpu/drm/mediatek/mtk_crtc.h | 1 + drivers/gpu/drm/mediatek/mtk_ddp_comp.c | 14 + drivers/gpu/drm/mediatek/mtk_ddp_comp.h | 5 + drivers/gpu/drm/mediatek/mtk_disp_ovl.c | 9 +- .../gpu/drm/mediatek/mtk_disp_ovl_adaptor.c | 1 + drivers/gpu/drm/mediatek/mtk_drm_drv.c | 13 +- drivers/gpu/drm/mediatek/mtk_gem.c | 114 ++++++++ drivers/gpu/drm/mediatek/mtk_gem.h | 12 + drivers/gpu/drm/mediatek/mtk_mdp_rdma.c | 8 +- drivers/gpu/drm/mediatek/mtk_mdp_rdma.h | 1 + drivers/gpu/drm/mediatek/mtk_plane.c | 25 ++ drivers/gpu/drm/mediatek/mtk_plane.h | 2 + include/uapi/drm/mediatek_drm.h | 47 ++++ 14 files changed, 500 insertions(+), 15 deletions(-) create mode 100644 include/uapi/drm/mediatek_drm.h -- 2.18.0

1 year, 9 months

[PATCH] dma-buf/sw-sync: don't enable IRQ from sync_print_obj()

by Tetsuo Handa

Since commit a6aa8fca4d79 ("dma-buf/sw-sync: Reduce irqsave/irqrestore from known context") by error replaced spin_unlock_irqrestore() with spin_unlock_irq() for both sync_debugfs_show() and sync_print_obj() despite sync_print_obj() is called from sync_debugfs_show(), lockdep complains inconsistent lock state warning. Use plain spin_{lock,unlock}() for sync_print_obj(), for sync_debugfs_show() is already using spin_{lock,unlock}_irq(). Reported-by: syzbot <syzbot+a225ee3df7e7f9372dbe(a)syzkaller.appspotmail.com> Closes: https://syzkaller.appspot.com/bug?extid=a225ee3df7e7f9372dbe Fixes: a6aa8fca4d79 ("dma-buf/sw-sync: Reduce irqsave/irqrestore from known context") Signed-off-by: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp> --- drivers/dma-buf/sync_debug.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/dma-buf/sync_debug.c b/drivers/dma-buf/sync_debug.c index 101394f16930..237bce21d1e7 100644 --- a/drivers/dma-buf/sync_debug.c +++ b/drivers/dma-buf/sync_debug.c @@ -110,12 +110,12 @@ static void sync_print_obj(struct seq_file *s, struct sync_timeline *obj) seq_printf(s, "%s: %d\n", obj->name, obj->value); - spin_lock_irq(&obj->lock); + spin_lock(&obj->lock); /* Caller already disabled IRQ. */ list_for_each(pos, &obj->pt_list) { struct sync_pt *pt = container_of(pos, struct sync_pt, link); sync_print_fence(s, &pt->base, false); } - spin_unlock_irq(&obj->lock); + spin_unlock(&obj->lock); } static void sync_print_sync_file(struct seq_file *s, -- 2.18.4

1 year, 9 months

[PATCH v2] dma-buf/fence-array: Add flex array to struct dma_fence_array

by Christophe JAILLET

This is an effort to get rid of all multiplications from allocation functions in order to prevent integer overflows [1][2]. The "struct dma_fence_array" can be refactored to add a flex array in order to have the "callback structures allocated behind the array" be more explicit. Do so: - makes the code more readable and safer. - allows using __counted_by() for additional checks - avoids some pointer arithmetic in dma_fence_array_enable_signaling() Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-a… [1] Link: https://github.com/KSPP/linux/issues/160 [2] Signed-off-by: Christophe JAILLET <christophe.jaillet(a)wanadoo.fr> Reviewed-by: Kees Cook <keescook(a)chromium.org> --- Compile tested only. Changes in v2: - Name the new field 'callbacks' instead of 'cb' [Christian König] v1: https://lore.kernel.org/all/d3204a5b4776553455c2cfb1def72f1dae0dba25.171605… --- drivers/dma-buf/dma-fence-array.c | 10 ++++------ include/linux/dma-fence-array.h | 3 +++ 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/dma-buf/dma-fence-array.c b/drivers/dma-buf/dma-fence-array.c index 9b3ce8948351..c74ac197d5fe 100644 --- a/drivers/dma-buf/dma-fence-array.c +++ b/drivers/dma-buf/dma-fence-array.c @@ -70,7 +70,7 @@ static void dma_fence_array_cb_func(struct dma_fence *f, static bool dma_fence_array_enable_signaling(struct dma_fence *fence) { struct dma_fence_array *array = to_dma_fence_array(fence); - struct dma_fence_array_cb *cb = (void *)(&array[1]); + struct dma_fence_array_cb *cb = array->callbacks; unsigned i; for (i = 0; i < array->num_fences; ++i) { @@ -168,22 +168,20 @@ struct dma_fence_array *dma_fence_array_create(int num_fences, bool signal_on_any) { struct dma_fence_array *array; - size_t size = sizeof(*array); WARN_ON(!num_fences || !fences); - /* Allocate the callback structures behind the array. */ - size += num_fences * sizeof(struct dma_fence_array_cb); - array = kzalloc(size, GFP_KERNEL); + array = kzalloc(struct_size(array, callbacks, num_fences), GFP_KERNEL); if (!array) return NULL; + array->num_fences = num_fences; + spin_lock_init(&array->lock); dma_fence_init(&array->base, &dma_fence_array_ops, &array->lock, context, seqno); init_irq_work(&array->work, irq_dma_fence_array_work); - array->num_fences = num_fences; atomic_set(&array->num_pending, signal_on_any ? 1 : num_fences); array->fences = fences; diff --git a/include/linux/dma-fence-array.h b/include/linux/dma-fence-array.h index ec7f25def392..29c5650c1038 100644 --- a/include/linux/dma-fence-array.h +++ b/include/linux/dma-fence-array.h @@ -33,6 +33,7 @@ struct dma_fence_array_cb { * @num_pending: fences in the array still pending * @fences: array of the fences * @work: internal irq_work function + * @callbacks: array of callback helpers */ struct dma_fence_array { struct dma_fence base; @@ -43,6 +44,8 @@ struct dma_fence_array { struct dma_fence **fences; struct irq_work work; + + struct dma_fence_array_cb callbacks[] __counted_by(num_fences); }; /** -- 2.45.1

1 year, 9 months

Re: Safety of opening up /dev/dma_heap/* to physically present users (udev uaccess tag) ?

by Daniel Vetter

On Wed, May 22, 2024 at 03:34:52PM +0200, Maxime Ripard wrote: > Hi, > > On Mon, May 06, 2024 at 03:38:24PM GMT, Daniel Vetter wrote: > > On Mon, May 06, 2024 at 02:05:12PM +0200, Maxime Ripard wrote: > > > Hi, > > > > > > On Mon, May 06, 2024 at 01:49:17PM GMT, Hans de Goede wrote: > > > > Hi dma-buf maintainers, et.al., > > > > > > > > Various people have been working on making complex/MIPI cameras work OOTB > > > > with mainline Linux kernels and an opensource userspace stack. > > > > > > > > The generic solution adds a software ISP (for Debayering and 3A) to > > > > libcamera. Libcamera's API guarantees that buffers handed to applications > > > > using it are dma-bufs so that these can be passed to e.g. a video encoder. > > > > > > > > In order to meet this API guarantee the libcamera software ISP allocates > > > > dma-bufs from userspace through one of the /dev/dma_heap/* heaps. For > > > > the Fedora COPR repo for the PoC of this: > > > > https://hansdegoede.dreamwidth.org/28153.html > > > > > > For the record, we're also considering using them for ARM KMS devices, > > > so it would be better if the solution wasn't only considering v4l2 > > > devices. > > > > > > > I have added a simple udev rule to give physically present users access > > > > to the dma_heap-s: > > > > > > > > KERNEL=="system", SUBSYSTEM=="dma_heap", TAG+="uaccess" > > > > > > > > (and on Rasperry Pi devices any users in the video group get access) > > > > > > > > This was just a quick fix for the PoC. Now that we are ready to move out > > > > of the PoC phase and start actually integrating this into distributions > > > > the question becomes if this is an acceptable solution; or if we need some > > > > other way to deal with this ? > > > > > > > > Specifically the question is if this will have any negative security > > > > implications? I can certainly see this being used to do some sort of > > > > denial of service attack on the system (1). This is especially true for > > > > the cma heap which generally speaking is a limited resource. > > > > > > There's plenty of other ways to exhaust CMA, like allocating too much > > > KMS or v4l2 buffers. I'm not sure we should consider dma-heaps > > > differently than those if it's part of our threat model. > > > > So generally for an arm soc where your display needs cma, your render node > > doesn't. And user applications only have access to the later, while only > > the compositor gets a kms fd through logind. At least in drm aside from > > vc4 there's really no render driver that just gives you access to cma and > > allows you to exhaust that, you need to be a compositor with drm master > > access to the display. > > > > Which means we're mostly protected against bad applications, and that's > > not a threat the "user physically sits in front of the machine accounts > > for", and which giving cma access to everyone would open up. And with > > flathub/snaps/... this is very much an issue. > > > > So you need more, either: > > > > - cgroups limits on dma-buf and dma-buf heaps. This has been bikeshedded > > for years and is just not really moving. > > For reference, are you talking about: > > https://lore.kernel.org/r/20220502231944.3891435-1-tjmercier@google.com > > Or has there been a new version of that recently? I think the design feedback from Tejun has changed to that system memory should be tracked with memcg instead (but that kinda leaves the open of what to do with cma), and only device memory be tracked with a separate cgroups controller. But I'm also not sure whether that would actually solve all the tracking/isolation requirements people tossed around or just gives us something that wont get the job done. Either way, yes I think that was the most recent code. -Sima -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch

1 year, 9 months

Re: [PATCH] dma-buf: handle testing kthreads creation failure

by T.J. Mercier

On Wed, May 22, 2024 at 5:24 AM Fedor Pchelkin <pchelkin(a)ispras.ru> wrote: > > kthread creation may possibly fail inside race_signal_callback(). In > such case stop the already started threads and return with error code. > > Found by Linux Verification Center (linuxtesting.org). > > Fixes: 2989f6451084 ("dma-buf: Add selftests for dma-fence") > Cc: stable(a)vger.kernel.org > Signed-off-by: Fedor Pchelkin <pchelkin(a)ispras.ru> > --- > drivers/dma-buf/st-dma-fence.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/dma-buf/st-dma-fence.c b/drivers/dma-buf/st-dma-fence.c > index b7c6f7ea9e0c..ab1ec4631578 100644 > --- a/drivers/dma-buf/st-dma-fence.c > +++ b/drivers/dma-buf/st-dma-fence.c > @@ -540,6 +540,12 @@ static int race_signal_callback(void *arg) > t[i].before = pass; > t[i].task = kthread_run(thread_signal_callback, &t[i], > "dma-fence:%d", i); > + if (IS_ERR(t[i].task)) { > + ret = PTR_ERR(t[i].task); > + while (--i >= 0) > + kthread_stop(t[i].task); This looks like it needs to be kthread_stop_put since get_task_struct was called for previous successful kthread_run calls. > + return ret; > + } > get_task_struct(t[i].task); > } > > -- > 2.39.2 >

1 year, 9 months

[PATCH] dma-buf/fence-array: Add flex array to struct dma_fence_array

by Christophe JAILLET

This is an effort to get rid of all multiplications from allocation functions in order to prevent integer overflows [1][2]. The "struct dma_fence_array" can be refactored to add a flex array in order to have the "callback structures allocated behind the array" be more explicit. Do so: - makes the code more readable and safer. - allows using __counted_by() for additional checks - avoids some pointer arithmetic in dma_fence_array_enable_signaling() Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-a… [1] Link: https://github.com/KSPP/linux/issues/160 [2] Signed-off-by: Christophe JAILLET <christophe.jaillet(a)wanadoo.fr> --- Compile tested only. Also, I don't think that 'cb' is a great name and the associated kernel-doc description could certainly be improved. Any proposal welcomed :) --- drivers/dma-buf/dma-fence-array.c | 10 ++++------ include/linux/dma-fence-array.h | 3 +++ 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/dma-buf/dma-fence-array.c b/drivers/dma-buf/dma-fence-array.c index 9b3ce8948351..9c55afaca607 100644 --- a/drivers/dma-buf/dma-fence-array.c +++ b/drivers/dma-buf/dma-fence-array.c @@ -70,7 +70,7 @@ static void dma_fence_array_cb_func(struct dma_fence *f, static bool dma_fence_array_enable_signaling(struct dma_fence *fence) { struct dma_fence_array *array = to_dma_fence_array(fence); - struct dma_fence_array_cb *cb = (void *)(&array[1]); + struct dma_fence_array_cb *cb = array->cb; unsigned i; for (i = 0; i < array->num_fences; ++i) { @@ -168,22 +168,20 @@ struct dma_fence_array *dma_fence_array_create(int num_fences, bool signal_on_any) { struct dma_fence_array *array; - size_t size = sizeof(*array); WARN_ON(!num_fences || !fences); - /* Allocate the callback structures behind the array. */ - size += num_fences * sizeof(struct dma_fence_array_cb); - array = kzalloc(size, GFP_KERNEL); + array = kzalloc(struct_size(array, cb, num_fences), GFP_KERNEL); if (!array) return NULL; + array->num_fences = num_fences; + spin_lock_init(&array->lock); dma_fence_init(&array->base, &dma_fence_array_ops, &array->lock, context, seqno); init_irq_work(&array->work, irq_dma_fence_array_work); - array->num_fences = num_fences; atomic_set(&array->num_pending, signal_on_any ? 1 : num_fences); array->fences = fences; diff --git a/include/linux/dma-fence-array.h b/include/linux/dma-fence-array.h index ec7f25def392..a793f9d5c73b 100644 --- a/include/linux/dma-fence-array.h +++ b/include/linux/dma-fence-array.h @@ -33,6 +33,7 @@ struct dma_fence_array_cb { * @num_pending: fences in the array still pending * @fences: array of the fences * @work: internal irq_work function + * @cb: array of callback helpers */ struct dma_fence_array { struct dma_fence base; @@ -43,6 +44,8 @@ struct dma_fence_array { struct dma_fence **fences; struct irq_work work; + + struct dma_fence_array_cb cb[] __counted_by(num_fences); }; /** -- 2.45.1

1 year, 9 months

[RFC PATCH v3 12/21] dma-buf/dma-resv: Introduce dma_resv_trylock_ctx()

by Thomas Hellström

For the drm_exec_trylock() functionality, there is a need to be able to trylock a dma-resv object as part of a drm_exec transaction. Therefore expose a variant of dma_resv_trylock that also takes a struct ww_acquire_ctx parameter. Cc: Christian König <christian.koenig(a)amd.com> Cc: Somalapuram Amaranath <Amaranath.Somalapuram(a)amd.com> Cc: Matthew Brost <matthew.brost(a)intel.com> Cc: <dri-devel(a)lists.freedesktop.org> Cc: <linaro-mm-sig(a)lists.linaro.org> Signed-off-by: Thomas Hellström <thomas.hellstrom(a)linux.intel.com> --- include/linux/dma-resv.h | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h index 8d0e34dad446..68dae8f2a22c 100644 --- a/include/linux/dma-resv.h +++ b/include/linux/dma-resv.h @@ -405,6 +405,27 @@ static inline int dma_resv_lock_slow_interruptible(struct dma_resv *obj, return ww_mutex_lock_slow_interruptible(&obj->lock, ctx); } +/** + * dma_resv_trylock_ctx - trylock the reservation object + * @obj: the reservation object + * @ctx: The ww acquire context or NULL. + * + * Tries to lock the reservation object for exclusive access and modification. + * Note, that the lock is only against other writers, readers will run + * concurrently with a writer under RCU. The seqlock is used to notify readers + * if they overlap with a writer. The context parameter ensures that other + * ww transactions can perform deadlock backoff if necessary, and that + * subsequent attempts to dma_resv_lock() @obj for @ctx will return + * -EALREADY. + * + * Return: true if the lock was acquired, false otherwise. + */ +static inline bool __must_check +dma_resv_trylock_ctx(struct dma_resv *obj, struct ww_acquire_ctx *ctx) +{ + return ww_mutex_trylock(&obj->lock, ctx); +} + /** * dma_resv_trylock - trylock the reservation object * @obj: the reservation object @@ -421,7 +442,7 @@ static inline int dma_resv_lock_slow_interruptible(struct dma_resv *obj, */ static inline bool __must_check dma_resv_trylock(struct dma_resv *obj) { - return ww_mutex_trylock(&obj->lock, NULL); + return dma_resv_trylock_ctx(obj, NULL); } /** -- 2.44.0

1 year, 9 months

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