| Message ID | 20210917123513.1106-3-christian.koenig@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [01/26] dma-buf: add dma_resv_for_each_fence_unlocked v2 | expand |
On Fri, Sep 17, 2021 at 02:34:49PM +0200, Christian König wrote: > A simpler version of the iterator to be used when the dma_resv object is > locked. > > Signed-off-by: Christian König <christian.koenig@amd.com> > --- > drivers/dma-buf/dma-resv.c | 33 +++++++++++++++++++++++++++++++++ > include/linux/dma-resv.h | 17 +++++++++++++++++ > 2 files changed, 50 insertions(+) > > diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c > index 3e77cad2c9d4..a3c79a99fb44 100644 > --- a/drivers/dma-buf/dma-resv.c > +++ b/drivers/dma-buf/dma-resv.c > @@ -384,6 +384,39 @@ struct dma_fence *dma_resv_iter_walk_unlocked(struct dma_resv_iter *cursor, > } > EXPORT_SYMBOL_GPL(dma_resv_iter_walk_unlocked); > > +/** > + * dma_resv_iter_walk - walk over fences in a dma_resv obj > + * @cursor: cursor to record the current position > + * @first: if we should start over > + * > + * Return all the fences in the dma_resv object while holding the > + * dma_resv::lock. > + */ > +struct dma_fence *dma_resv_iter_walk(struct dma_resv_iter *cursor, bool first) > +{ > + dma_resv_assert_held(cursor->obj); > + > + cursor->is_first = first; > + if (first) { > + struct dma_fence *fence; > + > + cursor->index = -1; > + cursor->fences = dma_resv_shared_list(cursor->obj); > + > + fence = dma_resv_excl_fence(cursor->obj); > + if (fence) > + return fence; > + } I think you can still use the shared iter_begin/end functions even with my suggestions for patch 1, but would mean changes here too. > + > + if (!cursor->all_fences || !cursor->fences || > + ++cursor->index >= cursor->fences->shared_count) > + return NULL; > + > + return rcu_dereference_protected(cursor->fences->shared[cursor->index], > + dma_resv_held(cursor->obj)); > +} > +EXPORT_SYMBOL_GPL(dma_resv_iter_walk); > + > /** > * dma_resv_copy_fences - Copy all fences from src to dst. > * @dst: the destination reservation object > diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h > index 693d16117153..8c968f8c9d33 100644 > --- a/include/linux/dma-resv.h > +++ b/include/linux/dma-resv.h > @@ -179,6 +179,7 @@ struct dma_resv_iter { > > struct dma_fence *dma_resv_iter_walk_unlocked(struct dma_resv_iter *cursor, > bool first); > +struct dma_fence *dma_resv_iter_walk(struct dma_resv_iter *cursor, bool first); > > /** > * dma_resv_iter_begin - initialize a dma_resv_iter object > @@ -233,6 +234,22 @@ static inline bool dma_resv_iter_is_exclusive(struct dma_resv_iter *cursor) > for (fence = dma_resv_iter_walk_unlocked(cursor, true); \ > fence; fence = dma_resv_iter_walk_unlocked(cursor, false)) > > +/** > + * dma_resv_for_each_fence - fence iterator > + * @cursor: a struct dma_resv_iter pointer > + * @obj: a dma_resv object pointer > + * @all_fences: true if all fences should be returned > + * @fence: the current fence > + * > + * Iterate over the fences in a struct dma_resv object while holding the > + * dma_resv::lock. @all_fences controls if the shared fences are returned as &dma_resv.lock is how you reference struct members in kerneldoc. I think you had this also in patch 1. > + * well. The cursor initialisation is part of the iterator. Please also link to the iter_begin/end functions here. Aside from doc nits and obviously changes due to changes in patch 1 (if we do them), this looks good. -Daniel > + */ > +#define dma_resv_for_each_fence(cursor, obj, all_fences, fence) \ > + for (dma_resv_iter_begin(cursor, obj, all_fences), \ > + fence = dma_resv_iter_walk(cursor, true); fence; \ > + fence = dma_resv_iter_walk(cursor, false)) > + > #define dma_resv_held(obj) lockdep_is_held(&(obj)->lock.base) > #define dma_resv_assert_held(obj) lockdep_assert_held(&(obj)->lock.base) > > -- > 2.25.1 >
On Fri, Sep 17, 2021 at 03:27:55PM +0200, Daniel Vetter wrote: > On Fri, Sep 17, 2021 at 02:34:49PM +0200, Christian König wrote: > > A simpler version of the iterator to be used when the dma_resv object is > > locked. > > > > Signed-off-by: Christian König <christian.koenig@amd.com> > > --- > > drivers/dma-buf/dma-resv.c | 33 +++++++++++++++++++++++++++++++++ > > include/linux/dma-resv.h | 17 +++++++++++++++++ > > 2 files changed, 50 insertions(+) > > > > diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c > > index 3e77cad2c9d4..a3c79a99fb44 100644 > > --- a/drivers/dma-buf/dma-resv.c > > +++ b/drivers/dma-buf/dma-resv.c > > @@ -384,6 +384,39 @@ struct dma_fence *dma_resv_iter_walk_unlocked(struct dma_resv_iter *cursor, > > } > > EXPORT_SYMBOL_GPL(dma_resv_iter_walk_unlocked); > > > > +/** > > + * dma_resv_iter_walk - walk over fences in a dma_resv obj > > + * @cursor: cursor to record the current position > > + * @first: if we should start over > > + * > > + * Return all the fences in the dma_resv object while holding the > > + * dma_resv::lock. I think we should document here that the fence is valid for as long as the dma_resv_lock is held, which is not like the _unlocked version, where the fence stops being valid either on the next call to iter_next() or on the call to iter_end() to clean up everything. Might be good to clarify that also for the unlocked version to be really precise here when the fence is valid and when not. -Daniel > > + */ > > +struct dma_fence *dma_resv_iter_walk(struct dma_resv_iter *cursor, bool first) > > +{ > > + dma_resv_assert_held(cursor->obj); > > + > > + cursor->is_first = first; > > + if (first) { > > + struct dma_fence *fence; > > + > > + cursor->index = -1; > > + cursor->fences = dma_resv_shared_list(cursor->obj); > > + > > + fence = dma_resv_excl_fence(cursor->obj); > > + if (fence) > > + return fence; > > + } > > I think you can still use the shared iter_begin/end functions even with my > suggestions for patch 1, but would mean changes here too. > > > + > > + if (!cursor->all_fences || !cursor->fences || > > + ++cursor->index >= cursor->fences->shared_count) > > + return NULL; > > + > > + return rcu_dereference_protected(cursor->fences->shared[cursor->index], > > + dma_resv_held(cursor->obj)); > > +} > > +EXPORT_SYMBOL_GPL(dma_resv_iter_walk); > > + > > /** > > * dma_resv_copy_fences - Copy all fences from src to dst. > > * @dst: the destination reservation object > > diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h > > index 693d16117153..8c968f8c9d33 100644 > > --- a/include/linux/dma-resv.h > > +++ b/include/linux/dma-resv.h > > @@ -179,6 +179,7 @@ struct dma_resv_iter { > > > > struct dma_fence *dma_resv_iter_walk_unlocked(struct dma_resv_iter *cursor, > > bool first); > > +struct dma_fence *dma_resv_iter_walk(struct dma_resv_iter *cursor, bool first); > > > > /** > > * dma_resv_iter_begin - initialize a dma_resv_iter object > > @@ -233,6 +234,22 @@ static inline bool dma_resv_iter_is_exclusive(struct dma_resv_iter *cursor) > > for (fence = dma_resv_iter_walk_unlocked(cursor, true); \ > > fence; fence = dma_resv_iter_walk_unlocked(cursor, false)) > > > > +/** > > + * dma_resv_for_each_fence - fence iterator > > + * @cursor: a struct dma_resv_iter pointer > > + * @obj: a dma_resv object pointer > > + * @all_fences: true if all fences should be returned > > + * @fence: the current fence > > + * > > + * Iterate over the fences in a struct dma_resv object while holding the > > + * dma_resv::lock. @all_fences controls if the shared fences are returned as > > &dma_resv.lock is how you reference struct members in kerneldoc. I think > you had this also in patch 1. > > > + * well. The cursor initialisation is part of the iterator. > > Please also link to the iter_begin/end functions here. > > Aside from doc nits and obviously changes due to changes in patch 1 (if we > do them), this looks good. > -Daniel > > > + */ > > +#define dma_resv_for_each_fence(cursor, obj, all_fences, fence) \ > > + for (dma_resv_iter_begin(cursor, obj, all_fences), \ > > + fence = dma_resv_iter_walk(cursor, true); fence; \ > > + fence = dma_resv_iter_walk(cursor, false)) > > + > > #define dma_resv_held(obj) lockdep_is_held(&(obj)->lock.base) > > #define dma_resv_assert_held(obj) lockdep_assert_held(&(obj)->lock.base) > > > > -- > > 2.25.1 > > > > -- > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch
diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index 3e77cad2c9d4..a3c79a99fb44 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -384,6 +384,39 @@ struct dma_fence *dma_resv_iter_walk_unlocked(struct dma_resv_iter *cursor, } EXPORT_SYMBOL_GPL(dma_resv_iter_walk_unlocked); +/** + * dma_resv_iter_walk - walk over fences in a dma_resv obj + * @cursor: cursor to record the current position + * @first: if we should start over + * + * Return all the fences in the dma_resv object while holding the + * dma_resv::lock. + */ +struct dma_fence *dma_resv_iter_walk(struct dma_resv_iter *cursor, bool first) +{ + dma_resv_assert_held(cursor->obj); + + cursor->is_first = first; + if (first) { + struct dma_fence *fence; + + cursor->index = -1; + cursor->fences = dma_resv_shared_list(cursor->obj); + + fence = dma_resv_excl_fence(cursor->obj); + if (fence) + return fence; + } + + if (!cursor->all_fences || !cursor->fences || + ++cursor->index >= cursor->fences->shared_count) + return NULL; + + return rcu_dereference_protected(cursor->fences->shared[cursor->index], + dma_resv_held(cursor->obj)); +} +EXPORT_SYMBOL_GPL(dma_resv_iter_walk); + /** * dma_resv_copy_fences - Copy all fences from src to dst. * @dst: the destination reservation object diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h index 693d16117153..8c968f8c9d33 100644 --- a/include/linux/dma-resv.h +++ b/include/linux/dma-resv.h @@ -179,6 +179,7 @@ struct dma_resv_iter { struct dma_fence *dma_resv_iter_walk_unlocked(struct dma_resv_iter *cursor, bool first); +struct dma_fence *dma_resv_iter_walk(struct dma_resv_iter *cursor, bool first); /** * dma_resv_iter_begin - initialize a dma_resv_iter object @@ -233,6 +234,22 @@ static inline bool dma_resv_iter_is_exclusive(struct dma_resv_iter *cursor) for (fence = dma_resv_iter_walk_unlocked(cursor, true); \ fence; fence = dma_resv_iter_walk_unlocked(cursor, false)) +/** + * dma_resv_for_each_fence - fence iterator + * @cursor: a struct dma_resv_iter pointer + * @obj: a dma_resv object pointer + * @all_fences: true if all fences should be returned + * @fence: the current fence + * + * Iterate over the fences in a struct dma_resv object while holding the + * dma_resv::lock. @all_fences controls if the shared fences are returned as + * well. The cursor initialisation is part of the iterator. + */ +#define dma_resv_for_each_fence(cursor, obj, all_fences, fence) \ + for (dma_resv_iter_begin(cursor, obj, all_fences), \ + fence = dma_resv_iter_walk(cursor, true); fence; \ + fence = dma_resv_iter_walk(cursor, false)) + #define dma_resv_held(obj) lockdep_is_held(&(obj)->lock.base) #define dma_resv_assert_held(obj) lockdep_assert_held(&(obj)->lock.base)
A simpler version of the iterator to be used when the dma_resv object is locked. Signed-off-by: Christian König <christian.koenig@amd.com> --- drivers/dma-buf/dma-resv.c | 33 +++++++++++++++++++++++++++++++++ include/linux/dma-resv.h | 17 +++++++++++++++++ 2 files changed, 50 insertions(+)