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@amd.com Cc: Somalapuram Amaranath Amaranath.Somalapuram@amd.com Cc: Matthew Brost matthew.brost@intel.com Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Signed-off-by: Thomas Hellström thomas.hellstrom@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); }

/**