| Message ID | 20210520190007.534046-3-jason@jlekstrand.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | dma-buf: Add an API for exporting sync files (v8) | expand |
On Thu, May 20, 2021 at 02:00:05PM -0500, Jason Ekstrand wrote: > Add a helper function to get a single fence representing > all fences in a dma_resv object. > > This fence is either the only one in the object or all not > signaled fences of the object in a flatted out dma_fence_array. > > v2 (Jason Ekstrand): > - Take reference of fences both for creating the dma_fence_array and in > the case where we return one fence. > - Handle the case where dma_resv_get_list() returns NULL > > v3 (Jason Ekstrand): > - Add an _rcu suffix because it is read-only > - Rewrite to use dma_resv_get_fences_rcu so it's RCU-safe > - Add an EXPORT_SYMBOL_GPL declaration > - Re-author the patch to Jason since very little is left of Christian > König's original patch > - Remove the extra fence argument > > v4 (Jason Ekstrand): > - Restore the extra fence argument > > Signed-off-by: Jason Ekstrand <jason@jlekstrand.net> > > get_singleton Spurious thing here. > --- > drivers/dma-buf/dma-resv.c | 122 +++++++++++++++++++++++++++++++++++++ > include/linux/dma-resv.h | 3 + > 2 files changed, 125 insertions(+) > > diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c > index 6ddbeb5dfbf65..25995fc15c370 100644 > --- a/drivers/dma-buf/dma-resv.c > +++ b/drivers/dma-buf/dma-resv.c > @@ -33,6 +33,8 @@ > */ > > #include <linux/dma-resv.h> > +#include <linux/dma-fence-chain.h> > +#include <linux/dma-fence-array.h> > #include <linux/export.h> > #include <linux/mm.h> > #include <linux/sched/mm.h> > @@ -49,6 +51,19 @@ > * write-side updates. > */ > > +/** > + * dma_fence_deep_dive_for_each - deep dive into the fence containers > + * @fence: resulting fence > + * @chain: variable for a dma_fence_chain > + * @index: index into a dma_fence_array > + * @head: starting point > + * > + * Helper to deep dive into the fence containers for flattening them. > + */ > +#define dma_fence_deep_dive_for_each(fence, chain, index, head) \ > + dma_fence_chain_for_each(chain, head) \ > + dma_fence_array_for_each(fence, index, chain) Since this is is just internal helper in the .c file we generally don't document it. Maybe small comment if you feel it's worth it. > + > DEFINE_WD_CLASS(reservation_ww_class); > EXPORT_SYMBOL(reservation_ww_class); > > @@ -517,6 +532,113 @@ int dma_resv_get_fences_rcu(struct dma_resv *obj, > } > EXPORT_SYMBOL_GPL(dma_resv_get_fences_rcu); > > +/** > + * dma_resv_get_singleton - get a single fence for the dma_resv object Name doesn't match here. > + * @obj: the reservation object > + * @extra: extra fence to add to the resulting array > + * @result: resulting dma_fence > + * > + * Get a single fence representing all unsignaled fences in the dma_resv object > + * plus the given extra fence. If we got only one fence return a new > + * reference to that, otherwise return a dma_fence_array object. > + * > + * RETURNS > + * Returns -NOMEM if allocations fail, zero otherwise. Kernel often encodes this in ERR_PTR so that you don't have to pass a pointer to store the result. Would feel more kerenl-y I think that way. So no result parameter, and on alloc failure you'd return return ERR_PTR(-ENOMEM); > + */ > +int dma_resv_get_singleton_rcu(struct dma_resv *obj, struct dma_fence *extra, tbh the _rcu here is confusing. I think _unlocked is the better suffix, maybe we should rename dma_resv_get_fences_rcu too for consistency. The rcu-ness of the lookup isn't leaked to callers at all, so no point giving them a panic. > + struct dma_fence **result) > +{ > + struct dma_fence **resv_fences, *fence, *chain, **fences; > + struct dma_fence_array *array; > + unsigned int num_resv_fences, num_fences; > + unsigned int ret, i, j; > + > + ret = dma_resv_get_fences_rcu(obj, NULL, &num_resv_fences, &resv_fences); > + if (ret) > + return ret; > + > + num_fences = 0; > + *result = NULL; > + > + if (num_resv_fences == 0 && !extra) > + return 0; > + > + for (i = 0; i < num_resv_fences; ++i) { > + dma_fence_deep_dive_for_each(fence, chain, j, resv_fences[i]) { > + if (dma_fence_is_signaled(fence)) > + continue; > + > + *result = fence; > + ++num_fences; > + } > + } > + > + if (extra) { > + dma_fence_deep_dive_for_each(fence, chain, j, extra) { > + if (dma_fence_is_signaled(fence)) > + continue; > + > + *result = fence; > + ++num_fences; > + } > + } > + > + if (num_fences <= 1) { > + *result = dma_fence_get(*result); > + goto put_resv_fences; > + } > + > + fences = kmalloc_array(num_fences, sizeof(struct dma_fence*), > + GFP_KERNEL); > + if (!fences) { > + *result = NULL; > + ret = -ENOMEM; > + goto put_resv_fences; > + } > + > + num_fences = 0; > + for (i = 0; i < num_resv_fences; ++i) { > + dma_fence_deep_dive_for_each(fence, chain, j, resv_fences[i]) { > + if (!dma_fence_is_signaled(fence)) > + fences[num_fences++] = dma_fence_get(fence); > + } > + } > + > + if (extra) { > + dma_fence_deep_dive_for_each(fence, chain, j, extra) { > + if (dma_fence_is_signaled(fence)) > + fences[num_fences++] = dma_fence_get(fence); > + } > + } > + > + if (num_fences <= 1) { > + *result = num_fences ? fences[0] : NULL; > + kfree(fences); > + goto put_resv_fences; > + } > + > + array = dma_fence_array_create(num_fences, fences, > + dma_fence_context_alloc(1), > + 1, false); > + if (array) { > + *result = &array->base; > + } else { > + *result = NULL; > + while (num_fences--) > + dma_fence_put(fences[num_fences]); > + kfree(fences); > + ret = -ENOMEM; > + } > + > +put_resv_fences: > + while (num_resv_fences--) > + dma_fence_put(resv_fences[num_resv_fences]); > + kfree(resv_fences); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(dma_resv_get_singleton_rcu); With the nits addressed: Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > + > /** > * dma_resv_wait_timeout_rcu - Wait on reservation's objects > * shared and/or exclusive fences. > diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h > index d44a77e8a7e34..d49ca263e78b4 100644 > --- a/include/linux/dma-resv.h > +++ b/include/linux/dma-resv.h > @@ -285,6 +285,9 @@ int dma_resv_get_fences_rcu(struct dma_resv *obj, > > int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src); > > +int dma_resv_get_singleton_rcu(struct dma_resv *obj, struct dma_fence *extra, > + struct dma_fence **result); > + > long dma_resv_wait_timeout_rcu(struct dma_resv *obj, bool wait_all, bool intr, > unsigned long timeout); > > -- > 2.31.1 >
Hi Jason,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on tegra-drm/drm/tegra/for-next]
[also build test WARNING on linus/master v5.13-rc2 next-20210521]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Jason-Ekstrand/dma-buf-Add-an-API-for-exporting-sync-files-v8/20210522-201251
base: git://anongit.freedesktop.org/tegra/linux.git drm/tegra/for-next
config: x86_64-randconfig-s031-20210522 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce:
# apt-get install sparse
# sparse version: v0.6.3-341-g8af24329-dirty
# https://github.com/0day-ci/linux/commit/925221f402201e7b1f665619dda2c5ee6d6324f1
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Jason-Ekstrand/dma-buf-Add-an-API-for-exporting-sync-files-v8/20210522-201251
git checkout 925221f402201e7b1f665619dda2c5ee6d6324f1
# save the attached .config to linux build tree
make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' W=1 ARCH=x86_64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
>> drivers/dma-buf/dma-resv.c:550: warning: expecting prototype for dma_resv_get_singleton(). Prototype was for dma_resv_get_singleton_rcu() instead
vim +550 drivers/dma-buf/dma-resv.c
534
535 /**
536 * dma_resv_get_singleton - get a single fence for the dma_resv object
537 * @obj: the reservation object
538 * @extra: extra fence to add to the resulting array
539 * @result: resulting dma_fence
540 *
541 * Get a single fence representing all unsignaled fences in the dma_resv object
542 * plus the given extra fence. If we got only one fence return a new
543 * reference to that, otherwise return a dma_fence_array object.
544 *
545 * RETURNS
546 * Returns -NOMEM if allocations fail, zero otherwise.
547 */
548 int dma_resv_get_singleton_rcu(struct dma_resv *obj, struct dma_fence *extra,
549 struct dma_fence **result)
> 550 {
551 struct dma_fence **resv_fences, *fence, *chain, **fences;
552 struct dma_fence_array *array;
553 unsigned int num_resv_fences, num_fences;
554 unsigned int ret, i, j;
555
556 ret = dma_resv_get_fences_rcu(obj, NULL, &num_resv_fences, &resv_fences);
557 if (ret)
558 return ret;
559
560 num_fences = 0;
561 *result = NULL;
562
563 if (num_resv_fences == 0 && !extra)
564 return 0;
565
566 for (i = 0; i < num_resv_fences; ++i) {
567 dma_fence_deep_dive_for_each(fence, chain, j, resv_fences[i]) {
568 if (dma_fence_is_signaled(fence))
569 continue;
570
571 *result = fence;
572 ++num_fences;
573 }
574 }
575
576 if (extra) {
577 dma_fence_deep_dive_for_each(fence, chain, j, extra) {
578 if (dma_fence_is_signaled(fence))
579 continue;
580
581 *result = fence;
582 ++num_fences;
583 }
584 }
585
586 if (num_fences <= 1) {
587 *result = dma_fence_get(*result);
588 goto put_resv_fences;
589 }
590
591 fences = kmalloc_array(num_fences, sizeof(struct dma_fence*),
592 GFP_KERNEL);
593 if (!fences) {
594 *result = NULL;
595 ret = -ENOMEM;
596 goto put_resv_fences;
597 }
598
599 num_fences = 0;
600 for (i = 0; i < num_resv_fences; ++i) {
601 dma_fence_deep_dive_for_each(fence, chain, j, resv_fences[i]) {
602 if (!dma_fence_is_signaled(fence))
603 fences[num_fences++] = dma_fence_get(fence);
604 }
605 }
606
607 if (extra) {
608 dma_fence_deep_dive_for_each(fence, chain, j, extra) {
609 if (dma_fence_is_signaled(fence))
610 fences[num_fences++] = dma_fence_get(fence);
611 }
612 }
613
614 if (num_fences <= 1) {
615 *result = num_fences ? fences[0] : NULL;
616 kfree(fences);
617 goto put_resv_fences;
618 }
619
620 array = dma_fence_array_create(num_fences, fences,
621 dma_fence_context_alloc(1),
622 1, false);
623 if (array) {
624 *result = &array->base;
625 } else {
626 *result = NULL;
627 while (num_fences--)
628 dma_fence_put(fences[num_fences]);
629 kfree(fences);
630 ret = -ENOMEM;
631 }
632
633 put_resv_fences:
634 while (num_resv_fences--)
635 dma_fence_put(resv_fences[num_resv_fences]);
636 kfree(resv_fences);
637
638 return ret;
639 }
640 EXPORT_SYMBOL_GPL(dma_resv_get_singleton_rcu);
641
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Hi Jason,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on tegra-drm/drm/tegra/for-next]
[also build test WARNING on linus/master v5.13-rc2 next-20210521]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Jason-Ekstrand/dma-buf-Add-an-API-for-exporting-sync-files-v8/20210522-201251
base: git://anongit.freedesktop.org/tegra/linux.git drm/tegra/for-next
config: x86_64-randconfig-a013-20210522 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project e84a9b9bb3051c35dea993cdad7b3d2575638f85)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install x86_64 cross compiling tool for clang build
# apt-get install binutils-x86-64-linux-gnu
# https://github.com/0day-ci/linux/commit/925221f402201e7b1f665619dda2c5ee6d6324f1
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Jason-Ekstrand/dma-buf-Add-an-API-for-exporting-sync-files-v8/20210522-201251
git checkout 925221f402201e7b1f665619dda2c5ee6d6324f1
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
>> drivers/dma-buf/dma-resv.c:550: warning: expecting prototype for dma_resv_get_singleton(). Prototype was for dma_resv_get_singleton_rcu() instead
vim +550 drivers/dma-buf/dma-resv.c
534
535 /**
536 * dma_resv_get_singleton - get a single fence for the dma_resv object
537 * @obj: the reservation object
538 * @extra: extra fence to add to the resulting array
539 * @result: resulting dma_fence
540 *
541 * Get a single fence representing all unsignaled fences in the dma_resv object
542 * plus the given extra fence. If we got only one fence return a new
543 * reference to that, otherwise return a dma_fence_array object.
544 *
545 * RETURNS
546 * Returns -NOMEM if allocations fail, zero otherwise.
547 */
548 int dma_resv_get_singleton_rcu(struct dma_resv *obj, struct dma_fence *extra,
549 struct dma_fence **result)
> 550 {
551 struct dma_fence **resv_fences, *fence, *chain, **fences;
552 struct dma_fence_array *array;
553 unsigned int num_resv_fences, num_fences;
554 unsigned int ret, i, j;
555
556 ret = dma_resv_get_fences_rcu(obj, NULL, &num_resv_fences, &resv_fences);
557 if (ret)
558 return ret;
559
560 num_fences = 0;
561 *result = NULL;
562
563 if (num_resv_fences == 0 && !extra)
564 return 0;
565
566 for (i = 0; i < num_resv_fences; ++i) {
567 dma_fence_deep_dive_for_each(fence, chain, j, resv_fences[i]) {
568 if (dma_fence_is_signaled(fence))
569 continue;
570
571 *result = fence;
572 ++num_fences;
573 }
574 }
575
576 if (extra) {
577 dma_fence_deep_dive_for_each(fence, chain, j, extra) {
578 if (dma_fence_is_signaled(fence))
579 continue;
580
581 *result = fence;
582 ++num_fences;
583 }
584 }
585
586 if (num_fences <= 1) {
587 *result = dma_fence_get(*result);
588 goto put_resv_fences;
589 }
590
591 fences = kmalloc_array(num_fences, sizeof(struct dma_fence*),
592 GFP_KERNEL);
593 if (!fences) {
594 *result = NULL;
595 ret = -ENOMEM;
596 goto put_resv_fences;
597 }
598
599 num_fences = 0;
600 for (i = 0; i < num_resv_fences; ++i) {
601 dma_fence_deep_dive_for_each(fence, chain, j, resv_fences[i]) {
602 if (!dma_fence_is_signaled(fence))
603 fences[num_fences++] = dma_fence_get(fence);
604 }
605 }
606
607 if (extra) {
608 dma_fence_deep_dive_for_each(fence, chain, j, extra) {
609 if (dma_fence_is_signaled(fence))
610 fences[num_fences++] = dma_fence_get(fence);
611 }
612 }
613
614 if (num_fences <= 1) {
615 *result = num_fences ? fences[0] : NULL;
616 kfree(fences);
617 goto put_resv_fences;
618 }
619
620 array = dma_fence_array_create(num_fences, fences,
621 dma_fence_context_alloc(1),
622 1, false);
623 if (array) {
624 *result = &array->base;
625 } else {
626 *result = NULL;
627 while (num_fences--)
628 dma_fence_put(fences[num_fences]);
629 kfree(fences);
630 ret = -ENOMEM;
631 }
632
633 put_resv_fences:
634 while (num_resv_fences--)
635 dma_fence_put(resv_fences[num_resv_fences]);
636 kfree(resv_fences);
637
638 return ret;
639 }
640 EXPORT_SYMBOL_GPL(dma_resv_get_singleton_rcu);
641
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
On Fri, May 21, 2021 at 12:48 PM Daniel Vetter <daniel@ffwll.ch> wrote: > > On Thu, May 20, 2021 at 02:00:05PM -0500, Jason Ekstrand wrote: > > Add a helper function to get a single fence representing > > all fences in a dma_resv object. > > > > This fence is either the only one in the object or all not > > signaled fences of the object in a flatted out dma_fence_array. > > > > v2 (Jason Ekstrand): > > - Take reference of fences both for creating the dma_fence_array and in > > the case where we return one fence. > > - Handle the case where dma_resv_get_list() returns NULL > > > > v3 (Jason Ekstrand): > > - Add an _rcu suffix because it is read-only > > - Rewrite to use dma_resv_get_fences_rcu so it's RCU-safe > > - Add an EXPORT_SYMBOL_GPL declaration > > - Re-author the patch to Jason since very little is left of Christian > > König's original patch > > - Remove the extra fence argument > > > > v4 (Jason Ekstrand): > > - Restore the extra fence argument > > > > Signed-off-by: Jason Ekstrand <jason@jlekstrand.net> > > > > get_singleton > > Spurious thing here. Fixed. > > --- > > drivers/dma-buf/dma-resv.c | 122 +++++++++++++++++++++++++++++++++++++ > > include/linux/dma-resv.h | 3 + > > 2 files changed, 125 insertions(+) > > > > diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c > > index 6ddbeb5dfbf65..25995fc15c370 100644 > > --- a/drivers/dma-buf/dma-resv.c > > +++ b/drivers/dma-buf/dma-resv.c > > @@ -33,6 +33,8 @@ > > */ > > > > #include <linux/dma-resv.h> > > +#include <linux/dma-fence-chain.h> > > +#include <linux/dma-fence-array.h> > > #include <linux/export.h> > > #include <linux/mm.h> > > #include <linux/sched/mm.h> > > @@ -49,6 +51,19 @@ > > * write-side updates. > > */ > > > > +/** > > + * dma_fence_deep_dive_for_each - deep dive into the fence containers > > + * @fence: resulting fence > > + * @chain: variable for a dma_fence_chain > > + * @index: index into a dma_fence_array > > + * @head: starting point > > + * > > + * Helper to deep dive into the fence containers for flattening them. > > + */ > > +#define dma_fence_deep_dive_for_each(fence, chain, index, head) \ > > + dma_fence_chain_for_each(chain, head) \ > > + dma_fence_array_for_each(fence, index, chain) > > Since this is is just internal helper in the .c file we generally don't > document it. Maybe small comment if you feel it's worth it. Sure, I can write LESS documentation. :-P > > + > > DEFINE_WD_CLASS(reservation_ww_class); > > EXPORT_SYMBOL(reservation_ww_class); > > > > @@ -517,6 +532,113 @@ int dma_resv_get_fences_rcu(struct dma_resv *obj, > > } > > EXPORT_SYMBOL_GPL(dma_resv_get_fences_rcu); > > > > +/** > > + * dma_resv_get_singleton - get a single fence for the dma_resv object > > Name doesn't match here. Fixed. > > + * @obj: the reservation object > > + * @extra: extra fence to add to the resulting array > > + * @result: resulting dma_fence > > + * > > + * Get a single fence representing all unsignaled fences in the dma_resv object > > + * plus the given extra fence. If we got only one fence return a new > > + * reference to that, otherwise return a dma_fence_array object. > > + * > > + * RETURNS > > + * Returns -NOMEM if allocations fail, zero otherwise. > > Kernel often encodes this in ERR_PTR so that you don't have to pass a > pointer to store the result. Would feel more kerenl-y I think that way. So > no result parameter, and on alloc failure you'd return Done. > return ERR_PTR(-ENOMEM); > > > + */ > > +int dma_resv_get_singleton_rcu(struct dma_resv *obj, struct dma_fence *extra, > > tbh the _rcu here is confusing. I think _unlocked is the better suffix, > maybe we should rename dma_resv_get_fences_rcu too for consistency. The > rcu-ness of the lookup isn't leaked to callers at all, so no point giving > them a panic. I can make that change. I'll also include a patch in the next re-send that renames all the _rcu helpers to _unlocked for consistency. --Jason > > + struct dma_fence **result) > > +{ > > + struct dma_fence **resv_fences, *fence, *chain, **fences; > > + struct dma_fence_array *array; > > + unsigned int num_resv_fences, num_fences; > > + unsigned int ret, i, j; > > + > > + ret = dma_resv_get_fences_rcu(obj, NULL, &num_resv_fences, &resv_fences); > > + if (ret) > > + return ret; > > + > > + num_fences = 0; > > + *result = NULL; > > + > > + if (num_resv_fences == 0 && !extra) > > + return 0; > > + > > + for (i = 0; i < num_resv_fences; ++i) { > > + dma_fence_deep_dive_for_each(fence, chain, j, resv_fences[i]) { > > + if (dma_fence_is_signaled(fence)) > > + continue; > > + > > + *result = fence; > > + ++num_fences; > > + } > > + } > > + > > + if (extra) { > > + dma_fence_deep_dive_for_each(fence, chain, j, extra) { > > + if (dma_fence_is_signaled(fence)) > > + continue; > > + > > + *result = fence; > > + ++num_fences; > > + } > > + } > > + > > + if (num_fences <= 1) { > > + *result = dma_fence_get(*result); > > + goto put_resv_fences; > > + } > > + > > + fences = kmalloc_array(num_fences, sizeof(struct dma_fence*), > > + GFP_KERNEL); > > + if (!fences) { > > + *result = NULL; > > + ret = -ENOMEM; > > + goto put_resv_fences; > > + } > > + > > + num_fences = 0; > > + for (i = 0; i < num_resv_fences; ++i) { > > + dma_fence_deep_dive_for_each(fence, chain, j, resv_fences[i]) { > > + if (!dma_fence_is_signaled(fence)) > > + fences[num_fences++] = dma_fence_get(fence); > > + } > > + } > > + > > + if (extra) { > > + dma_fence_deep_dive_for_each(fence, chain, j, extra) { > > + if (dma_fence_is_signaled(fence)) > > + fences[num_fences++] = dma_fence_get(fence); > > + } > > + } > > + > > + if (num_fences <= 1) { > > + *result = num_fences ? fences[0] : NULL; > > + kfree(fences); > > + goto put_resv_fences; > > + } > > + > > + array = dma_fence_array_create(num_fences, fences, > > + dma_fence_context_alloc(1), > > + 1, false); > > + if (array) { > > + *result = &array->base; > > + } else { > > + *result = NULL; > > + while (num_fences--) > > + dma_fence_put(fences[num_fences]); > > + kfree(fences); > > + ret = -ENOMEM; > > + } > > + > > +put_resv_fences: > > + while (num_resv_fences--) > > + dma_fence_put(resv_fences[num_resv_fences]); > > + kfree(resv_fences); > > + > > + return ret; > > +} > > +EXPORT_SYMBOL_GPL(dma_resv_get_singleton_rcu); > > With the nits addressed: > > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > > > + > > /** > > * dma_resv_wait_timeout_rcu - Wait on reservation's objects > > * shared and/or exclusive fences. > > diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h > > index d44a77e8a7e34..d49ca263e78b4 100644 > > --- a/include/linux/dma-resv.h > > +++ b/include/linux/dma-resv.h > > @@ -285,6 +285,9 @@ int dma_resv_get_fences_rcu(struct dma_resv *obj, > > > > int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src); > > > > +int dma_resv_get_singleton_rcu(struct dma_resv *obj, struct dma_fence *extra, > > + struct dma_fence **result); > > + > > long dma_resv_wait_timeout_rcu(struct dma_resv *obj, bool wait_all, bool intr, > > unsigned long timeout); > > > > -- > > 2.31.1 > > > > -- > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch
On Mon, May 24, 2021 at 03:04:35PM -0500, Jason Ekstrand wrote: > On Fri, May 21, 2021 at 12:48 PM Daniel Vetter <daniel@ffwll.ch> wrote: > > > > On Thu, May 20, 2021 at 02:00:05PM -0500, Jason Ekstrand wrote: > > > Add a helper function to get a single fence representing > > > all fences in a dma_resv object. > > > > > > This fence is either the only one in the object or all not > > > signaled fences of the object in a flatted out dma_fence_array. > > > > > > v2 (Jason Ekstrand): > > > - Take reference of fences both for creating the dma_fence_array and in > > > the case where we return one fence. > > > - Handle the case where dma_resv_get_list() returns NULL > > > > > > v3 (Jason Ekstrand): > > > - Add an _rcu suffix because it is read-only > > > - Rewrite to use dma_resv_get_fences_rcu so it's RCU-safe > > > - Add an EXPORT_SYMBOL_GPL declaration > > > - Re-author the patch to Jason since very little is left of Christian > > > König's original patch > > > - Remove the extra fence argument > > > > > > v4 (Jason Ekstrand): > > > - Restore the extra fence argument > > > > > > Signed-off-by: Jason Ekstrand <jason@jlekstrand.net> > > > > > > get_singleton > > > > Spurious thing here. > > Fixed. > > > > --- > > > drivers/dma-buf/dma-resv.c | 122 +++++++++++++++++++++++++++++++++++++ > > > include/linux/dma-resv.h | 3 + > > > 2 files changed, 125 insertions(+) > > > > > > diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c > > > index 6ddbeb5dfbf65..25995fc15c370 100644 > > > --- a/drivers/dma-buf/dma-resv.c > > > +++ b/drivers/dma-buf/dma-resv.c > > > @@ -33,6 +33,8 @@ > > > */ > > > > > > #include <linux/dma-resv.h> > > > +#include <linux/dma-fence-chain.h> > > > +#include <linux/dma-fence-array.h> > > > #include <linux/export.h> > > > #include <linux/mm.h> > > > #include <linux/sched/mm.h> > > > @@ -49,6 +51,19 @@ > > > * write-side updates. > > > */ > > > > > > +/** > > > + * dma_fence_deep_dive_for_each - deep dive into the fence containers > > > + * @fence: resulting fence > > > + * @chain: variable for a dma_fence_chain > > > + * @index: index into a dma_fence_array > > > + * @head: starting point > > > + * > > > + * Helper to deep dive into the fence containers for flattening them. > > > + */ > > > +#define dma_fence_deep_dive_for_each(fence, chain, index, head) \ > > > + dma_fence_chain_for_each(chain, head) \ > > > + dma_fence_array_for_each(fence, index, chain) > > > > Since this is is just internal helper in the .c file we generally don't > > document it. Maybe small comment if you feel it's worth it. > > Sure, I can write LESS documentation. :-P > > > > + > > > DEFINE_WD_CLASS(reservation_ww_class); > > > EXPORT_SYMBOL(reservation_ww_class); > > > > > > @@ -517,6 +532,113 @@ int dma_resv_get_fences_rcu(struct dma_resv *obj, > > > } > > > EXPORT_SYMBOL_GPL(dma_resv_get_fences_rcu); > > > > > > +/** > > > + * dma_resv_get_singleton - get a single fence for the dma_resv object > > > > Name doesn't match here. > > Fixed. > > > > + * @obj: the reservation object > > > + * @extra: extra fence to add to the resulting array > > > + * @result: resulting dma_fence > > > + * > > > + * Get a single fence representing all unsignaled fences in the dma_resv object > > > + * plus the given extra fence. If we got only one fence return a new > > > + * reference to that, otherwise return a dma_fence_array object. > > > + * > > > + * RETURNS > > > + * Returns -NOMEM if allocations fail, zero otherwise. > > > > Kernel often encodes this in ERR_PTR so that you don't have to pass a > > pointer to store the result. Would feel more kerenl-y I think that way. So > > no result parameter, and on alloc failure you'd return > > Done. > > > return ERR_PTR(-ENOMEM); > > > > > + */ > > > +int dma_resv_get_singleton_rcu(struct dma_resv *obj, struct dma_fence *extra, > > > > tbh the _rcu here is confusing. I think _unlocked is the better suffix, > > maybe we should rename dma_resv_get_fences_rcu too for consistency. The > > rcu-ness of the lookup isn't leaked to callers at all, so no point giving > > them a panic. > > I can make that change. I'll also include a patch in the next re-send > that renames all the _rcu helpers to _unlocked for consistency. Maybe double-check with Christian König whether he's on board with this bikeshed, but the current _rcu postfix we have in some dma_resv functions really confuses me. -Daniel > > --Jason > > > > + struct dma_fence **result) > > > +{ > > > + struct dma_fence **resv_fences, *fence, *chain, **fences; > > > + struct dma_fence_array *array; > > > + unsigned int num_resv_fences, num_fences; > > > + unsigned int ret, i, j; > > > + > > > + ret = dma_resv_get_fences_rcu(obj, NULL, &num_resv_fences, &resv_fences); > > > + if (ret) > > > + return ret; > > > + > > > + num_fences = 0; > > > + *result = NULL; > > > + > > > + if (num_resv_fences == 0 && !extra) > > > + return 0; > > > + > > > + for (i = 0; i < num_resv_fences; ++i) { > > > + dma_fence_deep_dive_for_each(fence, chain, j, resv_fences[i]) { > > > + if (dma_fence_is_signaled(fence)) > > > + continue; > > > + > > > + *result = fence; > > > + ++num_fences; > > > + } > > > + } > > > + > > > + if (extra) { > > > + dma_fence_deep_dive_for_each(fence, chain, j, extra) { > > > + if (dma_fence_is_signaled(fence)) > > > + continue; > > > + > > > + *result = fence; > > > + ++num_fences; > > > + } > > > + } > > > + > > > + if (num_fences <= 1) { > > > + *result = dma_fence_get(*result); > > > + goto put_resv_fences; > > > + } > > > + > > > + fences = kmalloc_array(num_fences, sizeof(struct dma_fence*), > > > + GFP_KERNEL); > > > + if (!fences) { > > > + *result = NULL; > > > + ret = -ENOMEM; > > > + goto put_resv_fences; > > > + } > > > + > > > + num_fences = 0; > > > + for (i = 0; i < num_resv_fences; ++i) { > > > + dma_fence_deep_dive_for_each(fence, chain, j, resv_fences[i]) { > > > + if (!dma_fence_is_signaled(fence)) > > > + fences[num_fences++] = dma_fence_get(fence); > > > + } > > > + } > > > + > > > + if (extra) { > > > + dma_fence_deep_dive_for_each(fence, chain, j, extra) { > > > + if (dma_fence_is_signaled(fence)) > > > + fences[num_fences++] = dma_fence_get(fence); > > > + } > > > + } > > > + > > > + if (num_fences <= 1) { > > > + *result = num_fences ? fences[0] : NULL; > > > + kfree(fences); > > > + goto put_resv_fences; > > > + } > > > + > > > + array = dma_fence_array_create(num_fences, fences, > > > + dma_fence_context_alloc(1), > > > + 1, false); > > > + if (array) { > > > + *result = &array->base; > > > + } else { > > > + *result = NULL; > > > + while (num_fences--) > > > + dma_fence_put(fences[num_fences]); > > > + kfree(fences); > > > + ret = -ENOMEM; > > > + } > > > + > > > +put_resv_fences: > > > + while (num_resv_fences--) > > > + dma_fence_put(resv_fences[num_resv_fences]); > > > + kfree(resv_fences); > > > + > > > + return ret; > > > +} > > > +EXPORT_SYMBOL_GPL(dma_resv_get_singleton_rcu); > > > > With the nits addressed: > > > > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > > > > > + > > > /** > > > * dma_resv_wait_timeout_rcu - Wait on reservation's objects > > > * shared and/or exclusive fences. > > > diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h > > > index d44a77e8a7e34..d49ca263e78b4 100644 > > > --- a/include/linux/dma-resv.h > > > +++ b/include/linux/dma-resv.h > > > @@ -285,6 +285,9 @@ int dma_resv_get_fences_rcu(struct dma_resv *obj, > > > > > > int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src); > > > > > > +int dma_resv_get_singleton_rcu(struct dma_resv *obj, struct dma_fence *extra, > > > + struct dma_fence **result); > > > + > > > long dma_resv_wait_timeout_rcu(struct dma_resv *obj, bool wait_all, bool intr, > > > unsigned long timeout); > > > > > > -- > > > 2.31.1 > > > > > > > -- > > Daniel Vetter > > Software Engineer, Intel Corporation > > http://blog.ffwll.ch
Am 25.05.21 um 14:38 schrieb Daniel Vetter: > On Mon, May 24, 2021 at 03:04:35PM -0500, Jason Ekstrand wrote: >> On Fri, May 21, 2021 at 12:48 PM Daniel Vetter <daniel@ffwll.ch> wrote: >>> On Thu, May 20, 2021 at 02:00:05PM -0500, Jason Ekstrand wrote: >>>> Add a helper function to get a single fence representing >>>> all fences in a dma_resv object. >>>> >>>> This fence is either the only one in the object or all not >>>> signaled fences of the object in a flatted out dma_fence_array. >>>> >>>> v2 (Jason Ekstrand): >>>> - Take reference of fences both for creating the dma_fence_array and in >>>> the case where we return one fence. >>>> - Handle the case where dma_resv_get_list() returns NULL >>>> >>>> v3 (Jason Ekstrand): >>>> - Add an _rcu suffix because it is read-only >>>> - Rewrite to use dma_resv_get_fences_rcu so it's RCU-safe >>>> - Add an EXPORT_SYMBOL_GPL declaration >>>> - Re-author the patch to Jason since very little is left of Christian >>>> König's original patch >>>> - Remove the extra fence argument >>>> >>>> v4 (Jason Ekstrand): >>>> - Restore the extra fence argument >>>> >>>> Signed-off-by: Jason Ekstrand <jason@jlekstrand.net> >>>> >>>> get_singleton >>> Spurious thing here. >> Fixed. >> >>>> --- >>>> drivers/dma-buf/dma-resv.c | 122 +++++++++++++++++++++++++++++++++++++ >>>> include/linux/dma-resv.h | 3 + >>>> 2 files changed, 125 insertions(+) >>>> >>>> diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c >>>> index 6ddbeb5dfbf65..25995fc15c370 100644 >>>> --- a/drivers/dma-buf/dma-resv.c >>>> +++ b/drivers/dma-buf/dma-resv.c >>>> @@ -33,6 +33,8 @@ >>>> */ >>>> >>>> #include <linux/dma-resv.h> >>>> +#include <linux/dma-fence-chain.h> >>>> +#include <linux/dma-fence-array.h> >>>> #include <linux/export.h> >>>> #include <linux/mm.h> >>>> #include <linux/sched/mm.h> >>>> @@ -49,6 +51,19 @@ >>>> * write-side updates. >>>> */ >>>> >>>> +/** >>>> + * dma_fence_deep_dive_for_each - deep dive into the fence containers >>>> + * @fence: resulting fence >>>> + * @chain: variable for a dma_fence_chain >>>> + * @index: index into a dma_fence_array >>>> + * @head: starting point >>>> + * >>>> + * Helper to deep dive into the fence containers for flattening them. >>>> + */ >>>> +#define dma_fence_deep_dive_for_each(fence, chain, index, head) \ >>>> + dma_fence_chain_for_each(chain, head) \ >>>> + dma_fence_array_for_each(fence, index, chain) >>> Since this is is just internal helper in the .c file we generally don't >>> document it. Maybe small comment if you feel it's worth it. >> Sure, I can write LESS documentation. :-P >> >>>> + >>>> DEFINE_WD_CLASS(reservation_ww_class); >>>> EXPORT_SYMBOL(reservation_ww_class); >>>> >>>> @@ -517,6 +532,113 @@ int dma_resv_get_fences_rcu(struct dma_resv *obj, >>>> } >>>> EXPORT_SYMBOL_GPL(dma_resv_get_fences_rcu); >>>> >>>> +/** >>>> + * dma_resv_get_singleton - get a single fence for the dma_resv object >>> Name doesn't match here. >> Fixed. >> >>>> + * @obj: the reservation object >>>> + * @extra: extra fence to add to the resulting array >>>> + * @result: resulting dma_fence >>>> + * >>>> + * Get a single fence representing all unsignaled fences in the dma_resv object >>>> + * plus the given extra fence. If we got only one fence return a new >>>> + * reference to that, otherwise return a dma_fence_array object. >>>> + * >>>> + * RETURNS >>>> + * Returns -NOMEM if allocations fail, zero otherwise. >>> Kernel often encodes this in ERR_PTR so that you don't have to pass a >>> pointer to store the result. Would feel more kerenl-y I think that way. So >>> no result parameter, and on alloc failure you'd return >> Done. >> >>> return ERR_PTR(-ENOMEM); >>> >>>> + */ >>>> +int dma_resv_get_singleton_rcu(struct dma_resv *obj, struct dma_fence *extra, >>> tbh the _rcu here is confusing. I think _unlocked is the better suffix, >>> maybe we should rename dma_resv_get_fences_rcu too for consistency. The >>> rcu-ness of the lookup isn't leaked to callers at all, so no point giving >>> them a panic. >> I can make that change. I'll also include a patch in the next re-send >> that renames all the _rcu helpers to _unlocked for consistency. > Maybe double-check with Christian König whether he's on board with this > bikeshed, but the current _rcu postfix we have in some dma_resv functions > really confuses me. Well I would say yes please :) The _rcu postfix was something I was always wondering about as well. Christian. > -Daniel > >> --Jason >> >>>> + struct dma_fence **result) >>>> +{ >>>> + struct dma_fence **resv_fences, *fence, *chain, **fences; >>>> + struct dma_fence_array *array; >>>> + unsigned int num_resv_fences, num_fences; >>>> + unsigned int ret, i, j; >>>> + >>>> + ret = dma_resv_get_fences_rcu(obj, NULL, &num_resv_fences, &resv_fences); >>>> + if (ret) >>>> + return ret; >>>> + >>>> + num_fences = 0; >>>> + *result = NULL; >>>> + >>>> + if (num_resv_fences == 0 && !extra) >>>> + return 0; >>>> + >>>> + for (i = 0; i < num_resv_fences; ++i) { >>>> + dma_fence_deep_dive_for_each(fence, chain, j, resv_fences[i]) { >>>> + if (dma_fence_is_signaled(fence)) >>>> + continue; >>>> + >>>> + *result = fence; >>>> + ++num_fences; >>>> + } >>>> + } >>>> + >>>> + if (extra) { >>>> + dma_fence_deep_dive_for_each(fence, chain, j, extra) { >>>> + if (dma_fence_is_signaled(fence)) >>>> + continue; >>>> + >>>> + *result = fence; >>>> + ++num_fences; >>>> + } >>>> + } >>>> + >>>> + if (num_fences <= 1) { >>>> + *result = dma_fence_get(*result); >>>> + goto put_resv_fences; >>>> + } >>>> + >>>> + fences = kmalloc_array(num_fences, sizeof(struct dma_fence*), >>>> + GFP_KERNEL); >>>> + if (!fences) { >>>> + *result = NULL; >>>> + ret = -ENOMEM; >>>> + goto put_resv_fences; >>>> + } >>>> + >>>> + num_fences = 0; >>>> + for (i = 0; i < num_resv_fences; ++i) { >>>> + dma_fence_deep_dive_for_each(fence, chain, j, resv_fences[i]) { >>>> + if (!dma_fence_is_signaled(fence)) >>>> + fences[num_fences++] = dma_fence_get(fence); >>>> + } >>>> + } >>>> + >>>> + if (extra) { >>>> + dma_fence_deep_dive_for_each(fence, chain, j, extra) { >>>> + if (dma_fence_is_signaled(fence)) >>>> + fences[num_fences++] = dma_fence_get(fence); >>>> + } >>>> + } >>>> + >>>> + if (num_fences <= 1) { >>>> + *result = num_fences ? fences[0] : NULL; >>>> + kfree(fences); >>>> + goto put_resv_fences; >>>> + } >>>> + >>>> + array = dma_fence_array_create(num_fences, fences, >>>> + dma_fence_context_alloc(1), >>>> + 1, false); >>>> + if (array) { >>>> + *result = &array->base; >>>> + } else { >>>> + *result = NULL; >>>> + while (num_fences--) >>>> + dma_fence_put(fences[num_fences]); >>>> + kfree(fences); >>>> + ret = -ENOMEM; >>>> + } >>>> + >>>> +put_resv_fences: >>>> + while (num_resv_fences--) >>>> + dma_fence_put(resv_fences[num_resv_fences]); >>>> + kfree(resv_fences); >>>> + >>>> + return ret; >>>> +} >>>> +EXPORT_SYMBOL_GPL(dma_resv_get_singleton_rcu); >>> With the nits addressed: >>> >>> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> >>> >>>> + >>>> /** >>>> * dma_resv_wait_timeout_rcu - Wait on reservation's objects >>>> * shared and/or exclusive fences. >>>> diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h >>>> index d44a77e8a7e34..d49ca263e78b4 100644 >>>> --- a/include/linux/dma-resv.h >>>> +++ b/include/linux/dma-resv.h >>>> @@ -285,6 +285,9 @@ int dma_resv_get_fences_rcu(struct dma_resv *obj, >>>> >>>> int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src); >>>> >>>> +int dma_resv_get_singleton_rcu(struct dma_resv *obj, struct dma_fence *extra, >>>> + struct dma_fence **result); >>>> + >>>> long dma_resv_wait_timeout_rcu(struct dma_resv *obj, bool wait_all, bool intr, >>>> unsigned long timeout); >>>> >>>> -- >>>> 2.31.1 >>>> >>> -- >>> Daniel Vetter >>> Software Engineer, Intel Corporation >>> https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fblog.ffwll.ch%2F&data=04%7C01%7Cchristian.koenig%40amd.com%7C4bfa8c05efd842e47f3b08d91f7a0121%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637575431134167291%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=8y%2BHz5GldUZK6Ey%2FuZUQUMg%2BObKticrSVX2gx3NBDOw%3D&reserved=0
diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index 6ddbeb5dfbf65..25995fc15c370 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -33,6 +33,8 @@ */ #include <linux/dma-resv.h> +#include <linux/dma-fence-chain.h> +#include <linux/dma-fence-array.h> #include <linux/export.h> #include <linux/mm.h> #include <linux/sched/mm.h> @@ -49,6 +51,19 @@ * write-side updates. */ +/** + * dma_fence_deep_dive_for_each - deep dive into the fence containers + * @fence: resulting fence + * @chain: variable for a dma_fence_chain + * @index: index into a dma_fence_array + * @head: starting point + * + * Helper to deep dive into the fence containers for flattening them. + */ +#define dma_fence_deep_dive_for_each(fence, chain, index, head) \ + dma_fence_chain_for_each(chain, head) \ + dma_fence_array_for_each(fence, index, chain) + DEFINE_WD_CLASS(reservation_ww_class); EXPORT_SYMBOL(reservation_ww_class); @@ -517,6 +532,113 @@ int dma_resv_get_fences_rcu(struct dma_resv *obj, } EXPORT_SYMBOL_GPL(dma_resv_get_fences_rcu); +/** + * dma_resv_get_singleton - get a single fence for the dma_resv object + * @obj: the reservation object + * @extra: extra fence to add to the resulting array + * @result: resulting dma_fence + * + * Get a single fence representing all unsignaled fences in the dma_resv object + * plus the given extra fence. If we got only one fence return a new + * reference to that, otherwise return a dma_fence_array object. + * + * RETURNS + * Returns -NOMEM if allocations fail, zero otherwise. + */ +int dma_resv_get_singleton_rcu(struct dma_resv *obj, struct dma_fence *extra, + struct dma_fence **result) +{ + struct dma_fence **resv_fences, *fence, *chain, **fences; + struct dma_fence_array *array; + unsigned int num_resv_fences, num_fences; + unsigned int ret, i, j; + + ret = dma_resv_get_fences_rcu(obj, NULL, &num_resv_fences, &resv_fences); + if (ret) + return ret; + + num_fences = 0; + *result = NULL; + + if (num_resv_fences == 0 && !extra) + return 0; + + for (i = 0; i < num_resv_fences; ++i) { + dma_fence_deep_dive_for_each(fence, chain, j, resv_fences[i]) { + if (dma_fence_is_signaled(fence)) + continue; + + *result = fence; + ++num_fences; + } + } + + if (extra) { + dma_fence_deep_dive_for_each(fence, chain, j, extra) { + if (dma_fence_is_signaled(fence)) + continue; + + *result = fence; + ++num_fences; + } + } + + if (num_fences <= 1) { + *result = dma_fence_get(*result); + goto put_resv_fences; + } + + fences = kmalloc_array(num_fences, sizeof(struct dma_fence*), + GFP_KERNEL); + if (!fences) { + *result = NULL; + ret = -ENOMEM; + goto put_resv_fences; + } + + num_fences = 0; + for (i = 0; i < num_resv_fences; ++i) { + dma_fence_deep_dive_for_each(fence, chain, j, resv_fences[i]) { + if (!dma_fence_is_signaled(fence)) + fences[num_fences++] = dma_fence_get(fence); + } + } + + if (extra) { + dma_fence_deep_dive_for_each(fence, chain, j, extra) { + if (dma_fence_is_signaled(fence)) + fences[num_fences++] = dma_fence_get(fence); + } + } + + if (num_fences <= 1) { + *result = num_fences ? fences[0] : NULL; + kfree(fences); + goto put_resv_fences; + } + + array = dma_fence_array_create(num_fences, fences, + dma_fence_context_alloc(1), + 1, false); + if (array) { + *result = &array->base; + } else { + *result = NULL; + while (num_fences--) + dma_fence_put(fences[num_fences]); + kfree(fences); + ret = -ENOMEM; + } + +put_resv_fences: + while (num_resv_fences--) + dma_fence_put(resv_fences[num_resv_fences]); + kfree(resv_fences); + + return ret; +} +EXPORT_SYMBOL_GPL(dma_resv_get_singleton_rcu); + /** * dma_resv_wait_timeout_rcu - Wait on reservation's objects * shared and/or exclusive fences. diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h index d44a77e8a7e34..d49ca263e78b4 100644 --- a/include/linux/dma-resv.h +++ b/include/linux/dma-resv.h @@ -285,6 +285,9 @@ int dma_resv_get_fences_rcu(struct dma_resv *obj, int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src); +int dma_resv_get_singleton_rcu(struct dma_resv *obj, struct dma_fence *extra, + struct dma_fence **result); + long dma_resv_wait_timeout_rcu(struct dma_resv *obj, bool wait_all, bool intr, unsigned long timeout);
Add a helper function to get a single fence representing all fences in a dma_resv object. This fence is either the only one in the object or all not signaled fences of the object in a flatted out dma_fence_array. v2 (Jason Ekstrand): - Take reference of fences both for creating the dma_fence_array and in the case where we return one fence. - Handle the case where dma_resv_get_list() returns NULL v3 (Jason Ekstrand): - Add an _rcu suffix because it is read-only - Rewrite to use dma_resv_get_fences_rcu so it's RCU-safe - Add an EXPORT_SYMBOL_GPL declaration - Re-author the patch to Jason since very little is left of Christian König's original patch - Remove the extra fence argument v4 (Jason Ekstrand): - Restore the extra fence argument Signed-off-by: Jason Ekstrand <jason@jlekstrand.net> get_singleton --- drivers/dma-buf/dma-resv.c | 122 +++++++++++++++++++++++++++++++++++++ include/linux/dma-resv.h | 3 + 2 files changed, 125 insertions(+)