path: root/drivers/gpu/drm/i915/i915_gem_execbuffer.c

/*
 * Copyright © 2008,2010 Intel Corporation
 *
 * 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, sublicense,
 * 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 above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * 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 NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS 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.
 *
 * Authors:
 *    Eric Anholt <eric@anholt.net>
 *    Chris Wilson <chris@chris-wilson.co.uk>
 *
 */

#include <drm/drmP.h>
#include <drm/i915_drm.h>
#include "i915_drv.h"
#include "i915_trace.h"
#include "intel_drv.h"
#include <linux/dma_remapping.h>

struct eb_objects {
	struct list_head objects;
	int and;
	union {
		struct drm_i915_gem_object *lut[0];
		struct hlist_head buckets[0];
	};
};

static struct eb_objects *
eb_create(struct drm_i915_gem_execbuffer2 *args)
{
	struct eb_objects *eb = NULL;

	if (args->flags & I915_EXEC_HANDLE_LUT) {
		int size = args->buffer_count;
		size *= sizeof(struct drm_i915_gem_object *);
		size += sizeof(struct eb_objects);
		eb = kmalloc(size, GFP_TEMPORARY | __GFP_NOWARN | __GFP_NORETRY);
	}

	if (eb == NULL) {
		int size = args->buffer_count;
		int count = PAGE_SIZE / sizeof(struct hlist_head) / 2;
		BUILD_BUG_ON(!is_power_of_2(PAGE_SIZE / sizeof(struct hlist_head)));
		while (count > 2*size)
			count >>= 1;
		eb = kzalloc(count*sizeof(struct hlist_head) +
			     sizeof(struct eb_objects),
			     GFP_TEMPORARY);
		if (eb == NULL)
			return eb;

		eb->and = count - 1;
	} else
		eb->and = -args->buffer_count;

	INIT_LIST_HEAD(&eb->objects);
	return eb;
}

static void
eb_reset(struct eb_objects *eb)
{
	if (eb->and >= 0)
		memset(eb->buckets, 0, (eb->and+1)*sizeof(struct hlist_head));
}

static int
eb_lookup_objects(struct eb_objects *eb,
		  struct drm_i915_gem_exec_object2 *exec,
		  const struct drm_i915_gem_execbuffer2 *args,
		  struct drm_file *file)
{
	int i;

	spin_lock(&file->table_lock);
	for (i = 0; i < args->buffer_count; i++) {
		struct drm_i915_gem_object *obj;

		obj = to_intel_bo(idr_find(&file->object_idr,