linux/drivers/gpu/drm/i915/gem/i915_gem_wait.c

/*
 * SPDX-License-Identifier: MIT
 *
 * Copyright © 2016 Intel Corporation
 */

#include <linux/dma-fence-array.h>
#include <linux/dma-fence-chain.h>
#include <linux/jiffies.h>

#include "gt/intel_engine.h"
#include "gt/intel_rps.h"

#include "i915_gem_ioctls.h"
#include "i915_gem_object.h"

static long
i915_gem_object_wait_fence(struct dma_fence *fence,
			   unsigned int flags,
			   long timeout)
{ … }

static void
i915_gem_object_boost(struct dma_resv *resv, unsigned int flags)
{ … }

static long
i915_gem_object_wait_reservation(struct dma_resv *resv,
				 unsigned int flags,
				 long timeout)
{ … }

static void fence_set_priority(struct dma_fence *fence,
			       const struct i915_sched_attr *attr)
{ … }

static inline bool __dma_fence_is_chain(const struct dma_fence *fence)
{ … }

void i915_gem_fence_wait_priority(struct dma_fence *fence,
				  const struct i915_sched_attr *attr)
{ … }

int
i915_gem_object_wait_priority(struct drm_i915_gem_object *obj,
			      unsigned int flags,
			      const struct i915_sched_attr *attr)
{ … }

/**
 * i915_gem_object_wait - Waits for rendering to the object to be completed
 * @obj: i915 gem object
 * @flags: how to wait (under a lock, for all rendering or just for writes etc)
 * @timeout: how long to wait
 */
int
i915_gem_object_wait(struct drm_i915_gem_object *obj,
		     unsigned int flags,
		     long timeout)
{ … }

static inline unsigned long nsecs_to_jiffies_timeout(const u64 n)
{ … }

static unsigned long to_wait_timeout(s64 timeout_ns)
{ … }

/**
 * i915_gem_wait_ioctl - implements DRM_IOCTL_I915_GEM_WAIT
 * @dev: drm device pointer
 * @data: ioctl data blob
 * @file: drm file pointer
 *
 * Returns 0 if successful, else an error is returned with the remaining time in
 * the timeout parameter.
 *  -ETIME: object is still busy after timeout
 *  -ERESTARTSYS: signal interrupted the wait
 *  -ENONENT: object doesn't exist
 * Also possible, but rare:
 *  -EAGAIN: incomplete, restart syscall
 *  -ENOMEM: damn
 *  -ENODEV: Internal IRQ fail
 *  -E?: The add request failed
 *
 * The wait ioctl with a timeout of 0 reimplements the busy ioctl. With any
 * non-zero timeout parameter the wait ioctl will wait for the given number of
 * nanoseconds on an object becoming unbusy. Since the wait itself does so
 * without holding struct_mutex the object may become re-busied before this
 * function completes. A similar but shorter * race condition exists in the busy
 * ioctl
 */
int
i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
{ … }

/**
 * i915_gem_object_wait_migration - Sync an accelerated migration operation
 * @obj: The migrating object.
 * @flags: waiting flags. Currently supports only I915_WAIT_INTERRUPTIBLE.
 *
 * Wait for any pending async migration operation on the object,
 * whether it's explicitly (i915_gem_object_migrate()) or implicitly
 * (swapin, initial clearing) initiated.
 *
 * Return: 0 if successful, -ERESTARTSYS if a signal was hit during waiting.
 */
int i915_gem_object_wait_migration(struct drm_i915_gem_object *obj,
				   unsigned int flags)
{ … }