diff options
Diffstat (limited to 'include/linux/dma-fence.h')
| -rw-r--r-- | include/linux/dma-fence.h | 149 |
1 files changed, 104 insertions, 45 deletions
diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 09e23adb351d..b12776883d14 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -21,6 +21,7 @@ #include <linux/sched.h> #include <linux/printk.h> #include <linux/rcupdate.h> +#include <linux/timekeeping.h> struct dma_fence; struct dma_fence_ops; @@ -168,8 +169,8 @@ struct dma_fence_ops { * implementation know that there is another driver waiting on the * signal (ie. hw->sw case). * - * This function can be called from atomic context, but not - * from irq context, so normal spinlocks can be used. + * This is called with irq's disabled, so only spinlocks which disable + * IRQ's can be used in the code outside of this callback. * * A return value of false indicates the fence already passed, * or some failure occurred that made it impossible to enable @@ -214,19 +215,15 @@ struct dma_fence_ops { * Custom wait implementation, defaults to dma_fence_default_wait() if * not set. * - * The dma_fence_default_wait implementation should work for any fence, as long - * as @enable_signaling works correctly. This hook allows drivers to - * have an optimized version for the case where a process context is - * already available, e.g. if @enable_signaling for the general case - * needs to set up a worker thread. + * Deprecated and should not be used by new implementations. Only used + * by existing implementations which need special handling for their + * hardware reset procedure. * * Must return -ERESTARTSYS if the wait is intr = true and the wait was * interrupted, and remaining jiffies if fence has signaled, or 0 if wait * timed out. Can also return other error values on custom implementations, * which should be treated as if the fence is signaled. For example a hardware * lockup could be reported like that. - * - * This callback is optional. */ signed long (*wait)(struct dma_fence *fence, bool intr, signed long timeout); @@ -242,25 +239,24 @@ struct dma_fence_ops { void (*release)(struct dma_fence *fence); /** - * @fence_value_str: + * @set_deadline: * - * Callback to fill in free-form debug info specific to this fence, like - * the sequence number. + * Callback to allow a fence waiter to inform the fence signaler of + * an upcoming deadline, such as vblank, by which point the waiter + * would prefer the fence to be signaled by. This is intended to + * give feedback to the fence signaler to aid in power management + * decisions, such as boosting GPU frequency. * - * This callback is optional. - */ - void (*fence_value_str)(struct dma_fence *fence, char *str, int size); - - /** - * @timeline_value_str: + * This is called without &dma_fence.lock held, it can be called + * multiple times and from any context. Locking is up to the callee + * if it has some state to manage. If multiple deadlines are set, + * the expectation is to track the soonest one. If the deadline is + * before the current time, it should be interpreted as an immediate + * deadline. * - * Fills in the current value of the timeline as a string, like the - * sequence number. Note that the specific fence passed to this function - * should not matter, drivers should only use it to look up the - * corresponding timeline structures. + * This callback is optional. */ - void (*timeline_value_str)(struct dma_fence *fence, - char *str, int size); + void (*set_deadline)(struct dma_fence *fence, ktime_t deadline); }; void dma_fence_init(struct dma_fence *fence, const struct dma_fence_ops *ops, @@ -268,6 +264,7 @@ void dma_fence_init(struct dma_fence *fence, const struct dma_fence_ops *ops, void dma_fence_release(struct kref *kref); void dma_fence_free(struct dma_fence *fence); +void dma_fence_describe(struct dma_fence *fence, struct seq_file *seq); /** * dma_fence_put - decreases refcount of the fence @@ -372,6 +369,9 @@ static inline void __dma_fence_might_wait(void) {} int dma_fence_signal(struct dma_fence *fence); int dma_fence_signal_locked(struct dma_fence *fence); +int dma_fence_signal_timestamp(struct dma_fence *fence, ktime_t timestamp); +int dma_fence_signal_timestamp_locked(struct dma_fence *fence, + ktime_t timestamp); signed long dma_fence_default_wait(struct dma_fence *fence, bool intr, signed long timeout); int dma_fence_add_callback(struct dma_fence *fence, @@ -479,6 +479,21 @@ static inline bool dma_fence_is_later(struct dma_fence *f1, } /** + * dma_fence_is_later_or_same - return true if f1 is later or same as f2 + * @f1: the first fence from the same context + * @f2: the second fence from the same context + * + * Returns true if f1 is chronologically later than f2 or the same fence. Both + * fences must be from the same context, since a seqno is not re-used across + * contexts. + */ +static inline bool dma_fence_is_later_or_same(struct dma_fence *f1, + struct dma_fence *f2) +{ + return f1 == f2 || dma_fence_is_later(f1, f2); +} + +/** * dma_fence_later - return the chronologically later fence * @f1: the first fence from the same context * @f2: the second fence from the same context @@ -538,6 +553,12 @@ int dma_fence_get_status(struct dma_fence *fence); * rather than success. This must be set before signaling (so that the value * is visible before any waiters on the signal callback are woken). This * helper exists to help catching erroneous setting of #dma_fence.error. + * + * Examples of error codes which drivers should use: + * + * * %-ENODATA This operation produced no data, no other operation affected. + * * %-ECANCELED All operations from the same context have been canceled. + * * %-ETIME Operation caused a timeout and potentially device reset. */ static inline void dma_fence_set_error(struct dma_fence *fence, int error) @@ -548,6 +569,25 @@ static inline void dma_fence_set_error(struct dma_fence *fence, fence->error = error; } +/** + * dma_fence_timestamp - helper to get the completion timestamp of a fence + * @fence: fence to get the timestamp from. + * + * After a fence is signaled the timestamp is updated with the signaling time, + * but setting the timestamp can race with tasks waiting for the signaling. This + * helper busy waits for the correct timestamp to appear. + */ +static inline ktime_t dma_fence_timestamp(struct dma_fence *fence) +{ + if (WARN_ON(!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))) + return ktime_get(); + + while (!test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags)) + cpu_relax(); + + return fence->timestamp; +} + signed long dma_fence_wait_timeout(struct dma_fence *, bool intr, signed long timeout); signed long dma_fence_wait_any_timeout(struct dma_fence **fences, @@ -583,29 +623,48 @@ static inline signed long dma_fence_wait(struct dma_fence *fence, bool intr) return ret < 0 ? ret : 0; } +void dma_fence_set_deadline(struct dma_fence *fence, ktime_t deadline); + struct dma_fence *dma_fence_get_stub(void); +struct dma_fence *dma_fence_allocate_private_stub(ktime_t timestamp); u64 dma_fence_context_alloc(unsigned num); -#define DMA_FENCE_TRACE(f, fmt, args...) \ - do { \ - struct dma_fence *__ff = (f); \ - if (IS_ENABLED(CONFIG_DMA_FENCE_TRACE)) \ - pr_info("f %llu#%llu: " fmt, \ - __ff->context, __ff->seqno, ##args); \ - } while (0) - -#define DMA_FENCE_WARN(f, fmt, args...) \ - do { \ - struct dma_fence *__ff = (f); \ - pr_warn("f %llu#%llu: " fmt, __ff->context, __ff->seqno,\ - ##args); \ - } while (0) - -#define DMA_FENCE_ERR(f, fmt, args...) \ - do { \ - struct dma_fence *__ff = (f); \ - pr_err("f %llu#%llu: " fmt, __ff->context, __ff->seqno, \ - ##args); \ - } while (0) +extern const struct dma_fence_ops dma_fence_array_ops; +extern const struct dma_fence_ops dma_fence_chain_ops; + +/** + * dma_fence_is_array - check if a fence is from the array subclass + * @fence: the fence to test + * + * Return true if it is a dma_fence_array and false otherwise. + */ +static inline bool dma_fence_is_array(struct dma_fence *fence) +{ + return fence->ops == &dma_fence_array_ops; +} + +/** + * dma_fence_is_chain - check if a fence is from the chain subclass + * @fence: the fence to test + * + * Return true if it is a dma_fence_chain and false otherwise. + */ +static inline bool dma_fence_is_chain(struct dma_fence *fence) +{ + return fence->ops == &dma_fence_chain_ops; +} + +/** + * dma_fence_is_container - check if a fence is a container for other fences + * @fence: the fence to test + * + * Return true if this fence is a container for other fences, false otherwise. + * This is important since we can't build up large fence structure or otherwise + * we run into recursion during operation on those fences. + */ +static inline bool dma_fence_is_container(struct dma_fence *fence) +{ + return dma_fence_is_array(fence) || dma_fence_is_chain(fence); +} #endif /* __LINUX_DMA_FENCE_H */ |