On 8/9/21 5:22 AM, Gal Pressman wrote:
> Fix a few typos in the documentation:
> - Remove an extraneous 'or'
> - 'unpins' -> 'unpin'
> - 'braket' -> 'bracket'
> - 'mappinsg' -> 'mappings'
> - 'fullfills' -> 'fulfills'
>
> Signed-off-by: Gal Pressman <galpress(a)amazon.com>
Reviewed-by: Randy Dunlap <rdunlap(a)infradead.org>
Thanks.
> ---
> include/linux/dma-buf.h | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
> index efdc56b9d95f..772403352767 100644
> --- a/include/linux/dma-buf.h
> +++ b/include/linux/dma-buf.h
> @@ -54,7 +54,7 @@ struct dma_buf_ops {
> * device), and otherwise need to fail the attach operation.
> *
> * The exporter should also in general check whether the current
> - * allocation fullfills the DMA constraints of the new device. If this
> + * allocation fulfills the DMA constraints of the new device. If this
> * is not the case, and the allocation cannot be moved, it should also
> * fail the attach operation.
> *
> @@ -146,7 +146,7 @@ struct dma_buf_ops {
> *
> * Returns:
> *
> - * A &sg_table scatter list of or the backing storage of the DMA buffer,
> + * A &sg_table scatter list of the backing storage of the DMA buffer,
> * already mapped into the device address space of the &device attached
> * with the provided &dma_buf_attachment. The addresses and lengths in
> * the scatter list are PAGE_SIZE aligned.
> @@ -168,7 +168,7 @@ struct dma_buf_ops {
> *
> * This is called by dma_buf_unmap_attachment() and should unmap and
> * release the &sg_table allocated in @map_dma_buf, and it is mandatory.
> - * For static dma_buf handling this might also unpins the backing
> + * For static dma_buf handling this might also unpin the backing
> * storage if this is the last mapping of the DMA buffer.
> */
> void (*unmap_dma_buf)(struct dma_buf_attachment *,
> @@ -237,7 +237,7 @@ struct dma_buf_ops {
> * This callback is used by the dma_buf_mmap() function
> *
> * Note that the mapping needs to be incoherent, userspace is expected
> - * to braket CPU access using the DMA_BUF_IOCTL_SYNC interface.
> + * to bracket CPU access using the DMA_BUF_IOCTL_SYNC interface.
> *
> * Because dma-buf buffers have invariant size over their lifetime, the
> * dma-buf core checks whether a vma is too large and rejects such
> @@ -464,7 +464,7 @@ static inline bool dma_buf_is_dynamic(struct dma_buf *dmabuf)
>
> /**
> * dma_buf_attachment_is_dynamic - check if a DMA-buf attachment uses dynamic
> - * mappinsg
> + * mappings
> * @attach: the DMA-buf attachment to check
> *
> * Returns true if a DMA-buf importer wants to call the map/unmap functions with
>
--
~Randy
On Mon, Aug 02, 2021 at 06:59:57PM +0800, Desmond Cheong Zhi Xi wrote:
> In drm_is_current_master_locked, accessing drm_file.master should be
> protected by either drm_file.master_lookup_lock or
> drm_device.master_mutex. This was previously awkward to assert with
> lockdep.
>
> Following patch ("locking/lockdep: Provide lockdep_assert{,_once}()
> helpers"), this assertion is now convenient. So we add in the
> assertion and explain this lock design in the kerneldoc.
>
> Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx(a)gmail.com>
> Acked-by: Boqun Feng <boqun.feng(a)gmail.com>
> Acked-by: Waiman Long <longman(a)redhat.com>
> Acked-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
Both patches pushed to drm-misc-next, thanks.
-Daniel
> ---
> drivers/gpu/drm/drm_auth.c | 6 +++---
> include/drm/drm_file.h | 4 ++++
> 2 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c
> index 9c24b8cc8e36..6f4d7ff23c80 100644
> --- a/drivers/gpu/drm/drm_auth.c
> +++ b/drivers/gpu/drm/drm_auth.c
> @@ -63,9 +63,9 @@
>
> static bool drm_is_current_master_locked(struct drm_file *fpriv)
> {
> - /* Either drm_device.master_mutex or drm_file.master_lookup_lock
> - * should be held here.
> - */
> + lockdep_assert_once(lockdep_is_held(&fpriv->master_lookup_lock) ||
> + lockdep_is_held(&fpriv->minor->dev->master_mutex));
> +
> return fpriv->is_master && drm_lease_owner(fpriv->master) == fpriv->minor->dev->master;
> }
>
> diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
> index 726cfe0ff5f5..a3acb7ac3550 100644
> --- a/include/drm/drm_file.h
> +++ b/include/drm/drm_file.h
> @@ -233,6 +233,10 @@ struct drm_file {
> * this only matches &drm_device.master if the master is the currently
> * active one.
> *
> + * To update @master, both &drm_device.master_mutex and
> + * @master_lookup_lock need to be held, therefore holding either of
> + * them is safe and enough for the read side.
> + *
> * When dereferencing this pointer, either hold struct
> * &drm_device.master_mutex for the duration of the pointer's use, or
> * use drm_file_get_master() if struct &drm_device.master_mutex is not
> --
> 2.25.1
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
Am 31.07.21 um 10:13 schrieb Tuo Li:
> The variable ttm is assigned to the variable gtt, and the variable gtt
> is checked in:
> if (gtt && gtt->userptr)
>
> This indicates that both ttm and gtt can be NULL.
> If so, a null-pointer dereference will occur:
> if (ttm->page_flags & TTM_PAGE_FLAG_SG)
>
> Also, some null-pointer dereferences will occur in the function
> ttm_pool_free() which is called in:
> return ttm_pool_free(&adev->mman.bdev.pool, ttm);
>
> To fix these possible null-pointer dereferences, the function returns
> when ttm is NULL.
NAK, same as with the other patch.
The ttm object is mandatory, asking the driver to destroy a ttm object
which doesn't exists makes no sense at all and is a bug in the upper layer.
The NULL check is just a leftover from when the gtt and ttm objects
where distinct. Please remove that one instead.
BTW: Bonus points for changing the (void *) cast into a much cleaner
container_of().
Thanks,
Christian.
>
> Reported-by: TOTE Robot <oslab(a)tsinghua.edu.cn>
> Signed-off-by: Tuo Li <islituo(a)gmail.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index 3a55f08e00e1..0216ca085f11 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -1146,7 +1146,10 @@ static void amdgpu_ttm_tt_unpopulate(struct ttm_device *bdev,
> struct amdgpu_ttm_tt *gtt = (void *)ttm;
> struct amdgpu_device *adev;
>
> - if (gtt && gtt->userptr) {
> + if (ttm == NULL)
> + return;
> +
> + if (gtt->userptr) {
> amdgpu_ttm_tt_set_user_pages(ttm, NULL);
> kfree(ttm->sg);
> ttm->sg = NULL;
Am 31.07.21 um 10:04 schrieb Tuo Li:
> The variable ttm is assigned to the variable gtt, and the variable gtt
> is checked in:
> if (gtt && gtt->userptr)
>
> This indicates that both ttm and gtt can be NULL.
> If so, a null-pointer dereference will occur:
> if (ttm->page_flags & TTM_PAGE_FLAG_SG)
>
> Also, some null-pointer dereferences will occur in the function
> ttm_pool_alloc() which is called in:
> return ttm_pool_alloc(&adev->mman.bdev.pool, ttm, ctx);
>
> To fix these possible null-pointer dereferences, the function returns
> -EINVAL when ttm is NULL.
NAK, the NULL test is just a leftover from when the objects where distinct.
Please remove the NULL test instead.
Regards,
Christian.
>
> Reported-by: TOTE Robot <oslab(a)tsinghua.edu.cn>
> Signed-off-by: Tuo Li <islituo(a)gmail.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index 3a55f08e00e1..80440f799c09 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -1120,8 +1120,11 @@ static int amdgpu_ttm_tt_populate(struct ttm_device *bdev,
> struct amdgpu_device *adev = amdgpu_ttm_adev(bdev);
> struct amdgpu_ttm_tt *gtt = (void *)ttm;
>
> + if (ttm == NULL)
> + return -EINVAL;
> +
> /* user pages are bound by amdgpu_ttm_tt_pin_userptr() */
> - if (gtt && gtt->userptr) {
> + if (gtt->userptr) {
> ttm->sg = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
> if (!ttm->sg)
> return -ENOMEM;
Entirely unused.
Signed-off-by: Christian König <christian.koenig(a)amd.com>
---
drivers/dma-buf/Makefile | 2 +-
drivers/dma-buf/seqno-fence.c | 71 ----------------------
include/linux/seqno-fence.h | 109 ----------------------------------
3 files changed, 1 insertion(+), 181 deletions(-)
delete mode 100644 drivers/dma-buf/seqno-fence.c
delete mode 100644 include/linux/seqno-fence.h
diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile
index 40d81f23cacf..1ef021273a06 100644
--- a/drivers/dma-buf/Makefile
+++ b/drivers/dma-buf/Makefile
@@ -1,6 +1,6 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-y := dma-buf.o dma-fence.o dma-fence-array.o dma-fence-chain.o \
- dma-resv.o seqno-fence.o
+ dma-resv.o
obj-$(CONFIG_DMABUF_HEAPS) += dma-heap.o
obj-$(CONFIG_DMABUF_HEAPS) += heaps/
obj-$(CONFIG_SYNC_FILE) += sync_file.o
diff --git a/drivers/dma-buf/seqno-fence.c b/drivers/dma-buf/seqno-fence.c
deleted file mode 100644
index bfe14e94c488..000000000000
--- a/drivers/dma-buf/seqno-fence.c
+++ /dev/null
@@ -1,71 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * seqno-fence, using a dma-buf to synchronize fencing
- *
- * Copyright (C) 2012 Texas Instruments
- * Copyright (C) 2012-2014 Canonical Ltd
- * Authors:
- * Rob Clark <robdclark(a)gmail.com>
- * Maarten Lankhorst <maarten.lankhorst(a)canonical.com>
- */
-
-#include <linux/slab.h>
-#include <linux/export.h>
-#include <linux/seqno-fence.h>
-
-static const char *seqno_fence_get_driver_name(struct dma_fence *fence)
-{
- struct seqno_fence *seqno_fence = to_seqno_fence(fence);
-
- return seqno_fence->ops->get_driver_name(fence);
-}
-
-static const char *seqno_fence_get_timeline_name(struct dma_fence *fence)
-{
- struct seqno_fence *seqno_fence = to_seqno_fence(fence);
-
- return seqno_fence->ops->get_timeline_name(fence);
-}
-
-static bool seqno_enable_signaling(struct dma_fence *fence)
-{
- struct seqno_fence *seqno_fence = to_seqno_fence(fence);
-
- return seqno_fence->ops->enable_signaling(fence);
-}
-
-static bool seqno_signaled(struct dma_fence *fence)
-{
- struct seqno_fence *seqno_fence = to_seqno_fence(fence);
-
- return seqno_fence->ops->signaled && seqno_fence->ops->signaled(fence);
-}
-
-static void seqno_release(struct dma_fence *fence)
-{
- struct seqno_fence *f = to_seqno_fence(fence);
-
- dma_buf_put(f->sync_buf);
- if (f->ops->release)
- f->ops->release(fence);
- else
- dma_fence_free(&f->base);
-}
-
-static signed long seqno_wait(struct dma_fence *fence, bool intr,
- signed long timeout)
-{
- struct seqno_fence *f = to_seqno_fence(fence);
-
- return f->ops->wait(fence, intr, timeout);
-}
-
-const struct dma_fence_ops seqno_fence_ops = {
- .get_driver_name = seqno_fence_get_driver_name,
- .get_timeline_name = seqno_fence_get_timeline_name,
- .enable_signaling = seqno_enable_signaling,
- .signaled = seqno_signaled,
- .wait = seqno_wait,
- .release = seqno_release,
-};
-EXPORT_SYMBOL(seqno_fence_ops);
diff --git a/include/linux/seqno-fence.h b/include/linux/seqno-fence.h
deleted file mode 100644
index 3cca2b8fac43..000000000000
--- a/include/linux/seqno-fence.h
+++ /dev/null
@@ -1,109 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * seqno-fence, using a dma-buf to synchronize fencing
- *
- * Copyright (C) 2012 Texas Instruments
- * Copyright (C) 2012 Canonical Ltd
- * Authors:
- * Rob Clark <robdclark(a)gmail.com>
- * Maarten Lankhorst <maarten.lankhorst(a)canonical.com>
- */
-
-#ifndef __LINUX_SEQNO_FENCE_H
-#define __LINUX_SEQNO_FENCE_H
-
-#include <linux/dma-fence.h>
-#include <linux/dma-buf.h>
-
-enum seqno_fence_condition {
- SEQNO_FENCE_WAIT_GEQUAL,
- SEQNO_FENCE_WAIT_NONZERO
-};
-
-struct seqno_fence {
- struct dma_fence base;
-
- const struct dma_fence_ops *ops;
- struct dma_buf *sync_buf;
- uint32_t seqno_ofs;
- enum seqno_fence_condition condition;
-};
-
-extern const struct dma_fence_ops seqno_fence_ops;
-
-/**
- * to_seqno_fence - cast a fence to a seqno_fence
- * @fence: fence to cast to a seqno_fence
- *
- * Returns NULL if the fence is not a seqno_fence,
- * or the seqno_fence otherwise.
- */
-static inline struct seqno_fence *
-to_seqno_fence(struct dma_fence *fence)
-{
- if (fence->ops != &seqno_fence_ops)
- return NULL;
- return container_of(fence, struct seqno_fence, base);
-}
-
-/**
- * seqno_fence_init - initialize a seqno fence
- * @fence: seqno_fence to initialize
- * @lock: pointer to spinlock to use for fence
- * @sync_buf: buffer containing the memory location to signal on
- * @context: the execution context this fence is a part of
- * @seqno_ofs: the offset within @sync_buf
- * @seqno: the sequence # to signal on
- * @cond: fence wait condition
- * @ops: the fence_ops for operations on this seqno fence
- *
- * This function initializes a struct seqno_fence with passed parameters,
- * and takes a reference on sync_buf which is released on fence destruction.
- *
- * A seqno_fence is a dma_fence which can complete in software when
- * enable_signaling is called, but it also completes when
- * (s32)((sync_buf)[seqno_ofs] - seqno) >= 0 is true
- *
- * The seqno_fence will take a refcount on the sync_buf until it's
- * destroyed, but actual lifetime of sync_buf may be longer if one of the
- * callers take a reference to it.
- *
- * Certain hardware have instructions to insert this type of wait condition
- * in the command stream, so no intervention from software would be needed.
- * This type of fence can be destroyed before completed, however a reference
- * on the sync_buf dma-buf can be taken. It is encouraged to re-use the same
- * dma-buf for sync_buf, since mapping or unmapping the sync_buf to the
- * device's vm can be expensive.
- *
- * It is recommended for creators of seqno_fence to call dma_fence_signal()
- * before destruction. This will prevent possible issues from wraparound at
- * time of issue vs time of check, since users can check dma_fence_is_signaled()
- * before submitting instructions for the hardware to wait on the fence.
- * However, when ops.enable_signaling is not called, it doesn't have to be
- * done as soon as possible, just before there's any real danger of seqno
- * wraparound.
- */
-static inline void
-seqno_fence_init(struct seqno_fence *fence, spinlock_t *lock,
- struct dma_buf *sync_buf, uint32_t context,
- uint32_t seqno_ofs, uint32_t seqno,
- enum seqno_fence_condition cond,
- const struct dma_fence_ops *ops)
-{
- BUG_ON(!fence || !sync_buf || !ops);
- BUG_ON(!ops->wait || !ops->enable_signaling ||
- !ops->get_driver_name || !ops->get_timeline_name);
-
- /*
- * ops is used in dma_fence_init for get_driver_name, so needs to be
- * initialized first
- */
- fence->ops = ops;
- dma_fence_init(&fence->base, &seqno_fence_ops, lock, context, seqno);
- get_dma_buf(sync_buf);
- fence->sync_buf = sync_buf;
- fence->seqno_ofs = seqno_ofs;
- fence->condition = cond;
-}
-
-#endif /* __LINUX_SEQNO_FENCE_H */
--
2.25.1
From: Rob Clark <robdclark(a)chromium.org>
Based on discussion from a previous series[1] to add a "boost" mechanism
when, for example, vblank deadlines are missed. Instead of a boost
callback, this approach adds a way to set a deadline on the fence, by
which the waiter would like to see the fence signalled.
I've not yet had a chance to re-work the drm/msm part of this, but
wanted to send this out as an RFC in case I don't have a chance to
finish the drm/msm part this week.
Original description:
In some cases, like double-buffered rendering, missing vblanks can
trick the GPU into running at a lower frequence, when really we
want to be running at a higher frequency to not miss the vblanks
in the first place.
This is partially inspired by a trick i915 does, but implemented
via dma-fence for a couple of reasons:
1) To continue to be able to use the atomic helpers
2) To support cases where display and gpu are different drivers
[1] https://patchwork.freedesktop.org/series/90331/
Rob Clark (4):
dma-fence: Add deadline awareness
drm/vblank: Add helper to get next vblank time
drm/atomic-helper: Set fence deadline for vblank
drm/scheduler: Add fence deadline support
drivers/dma-buf/dma-fence.c | 39 +++++++++++++++++++++++++
drivers/gpu/drm/drm_atomic_helper.c | 36 +++++++++++++++++++++++
drivers/gpu/drm/drm_vblank.c | 31 ++++++++++++++++++++
drivers/gpu/drm/scheduler/sched_fence.c | 10 +++++++
drivers/gpu/drm/scheduler/sched_main.c | 3 ++
include/drm/drm_vblank.h | 1 +
include/linux/dma-fence.h | 17 +++++++++++
7 files changed, 137 insertions(+)
--
2.31.1