linux/drivers/gpu/drm/radeon/radeon_semaphore.c

/*
 * Copyright 2011 Christian König.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 */
/*
 * Authors:
 *    Christian König <deathsimple@vodafone.de>
 */
#include <drm/drmP.h>
#include "radeon.h"
#include "radeon_trace.h"

int radeon_semaphore_create(struct radeon_device *rdev,
			    struct radeon_semaphore **semaphore)
{
	uint64_t *cpu_addr;
	int i, r;

	*semaphore = kmalloc(sizeof(struct radeon_semaphore), GFP_KERNEL);
	if (*semaphore == NULL) {
		return -ENOMEM;
	}
	r = radeon_sa_bo_new(rdev, &rdev->ring_tmp_bo, &(*semaphore)->sa_bo,
			     8 * RADEON_NUM_SYNCS, 8);
	if (r) {
		kfree(*semaphore);
		*semaphore = NULL;
		return r;
	}
	(*semaphore)->waiters = 0;
	(*semaphore)->gpu_addr = radeon_sa_bo_gpu_addr((*semaphore)->sa_bo);

	cpu_addr = radeon_sa_bo_cpu_addr((*semaphore)->sa_bo);
	for (i = 0; i < RADEON_NUM_SYNCS; ++i)
		cpu_addr[i] = 0;

	for (i = 0; i < RADEON_NUM_RINGS; ++i)
		(*semaphore)->sync_to[i] = NULL;

	return 0;
}

bool radeon_semaphore_emit_signal(struct radeon_device *rdev, int ridx,
			          struct radeon_semaphore *semaphore)
{
	struct radeon_ring *ring = &rdev->ring[ridx];

	trace_radeon_semaphore_signale(ridx, semaphore);

	if (radeon_semaphore_ring_emit(rdev, ridx, ring, semaphore, false)) {
		--semaphore->waiters;

		/* for debugging lockup only, used by sysfs debug files */
		ring->last_semaphore_signal_addr = semaphore->gpu_addr;
		return true;
	}
	return false;
}

bool radeon_semaphore_emit_wait(struct radeon_device *rdev, int ridx,
			        struct radeon_semaphore *semaphore)
{
	struct radeon_ring *ring = &rdev->ring[ridx];

	trace_radeon_semaphore_wait(ridx, semaphore);

	if (radeon_semaphore_ring_emit(rdev, ridx, ring, semaphore, true)) {
		++semaphore->waiters;

		/* for debugging lockup only, used by sysfs debug files */
		ring->last_semaphore_wait_addr = semaphore->gpu_addr;
		return true;
	}
	return false;
}

/**
 * radeon_semaphore_sync_to - use the semaphore to sync to a fence
 *
 * @semaphore: semaphore object to add fence to
 * @fence: fence to sync to
 *
 * Sync to the fence using this semaphore object
 */
void radeon_semaphore_sync_to(struct radeon_semaphore *semaphore,
			      struct radeon_fence *fence)
{
        struct radeon_fence *other;

        if (!fence)
                return;

        other = semaphore->sync_to[fence->ring];
        semaphore->sync_to[fence->ring] = radeon_fence_later(fence, other);
}

/**
 * radeon_semaphore_sync_rings - sync ring to all registered fences
 *
 * @rdev: radeon_device pointer
 * @semaphore: semaphore object to use for sync
 * @ring: ring that needs sync
 *
 * Ensure that all registered fences are signaled before letting
 * the ring continue. The caller must hold the ring lock.
 */
int radeon_semaphore_sync_rings(struct radeon_device *rdev,
				struct radeon_semaphore *semaphore,
				int ring)
{
	unsigned count = 0;
	int i, r;

        for (i = 0; i < RADEON_NUM_RINGS; ++i) {
		struct radeon_fence *fence = semaphore->sync_to[i];

		/* check if we really need to sync */
                if (!radeon_fence_need_sync(fence, ring))
			continue;

		/* prevent GPU deadlocks */
		if (!rdev->ring[i].ready) {
			dev_err(rdev->dev, "Syncing to a disabled ring!");
			return -EINVAL;
		}

		if (++count > RADEON_NUM_SYNCS) {
			/* not enough room, wait manually */
			r = radeon_fence_wait(fence, false);
			if (r)
				return r;
			continue;
		}

		/* allocate enough space for sync command */
		r = radeon_ring_alloc(rdev, &rdev->ring[i], 16);
		if (r) {
			return r;
		}

		/* emit the signal semaphore */
		if (!radeon_semaphore_emit_signal(rdev, i, semaphore)) {
			/* signaling wasn't successful wait manually */
			radeon_ring_undo(&rdev->ring[i]);
			r = radeon_fence_wait(fence, false);
			if (r)
				return r;
			continue;
		}

		/* we assume caller has already allocated space on waiters ring */
		if (!radeon_semaphore_emit_wait(rdev, ring, semaphore)) {
			/* waiting wasn't successful wait manually */
			radeon_ring_undo(&rdev->ring[i]);
			r = radeon_fence_wait(fence, false);
			if (r)
				return r;
			continue;
		}

		radeon_ring_commit(rdev, &rdev->ring[i], false);
		radeon_fence_note_sync(fence, ring);

		semaphore->gpu_addr += 8;
	}

	return 0;
}

void radeon_semaphore_free(struct radeon_device *rdev,
			   struct radeon_semaphore **semaphore,
			   struct radeon_fence *fence)
{
	if (semaphore == NULL || *semaphore == NULL) {
		return;
	}
	if ((*semaphore)->waiters > 0) {
		dev_err(rdev->dev, "semaphore %p has more waiters than signalers,"
			" hardware lockup imminent!\n", *semaphore);
	}
	radeon_sa_bo_free(rdev, &(*semaphore)->sa_bo, fence);
	kfree(*semaphore);
	*semaphore = NULL;
}