/*
 * Copyright © 2014 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:
 *    Mika Kuoppala <mika.kuoppala@intel.com>
 *
 */

#include "i915_drv.h"
#include "intel_renderstate.h"

struct i915_render_state {
	struct drm_i915_gem_object *obj;
	unsigned long ggtt_offset;
	u32 *batch;
	u32 size;
	u32 len;
};

static struct i915_render_state *render_state_alloc(struct drm_device *dev)
{
	struct i915_render_state *so;
	struct page *page;
	int ret;

	so = kzalloc(sizeof(*so), GFP_KERNEL);
	if (!so)
		return ERR_PTR(-ENOMEM);

	so->obj = i915_gem_alloc_object(dev, 4096);
	if (so->obj == NULL) {
		ret = -ENOMEM;
		goto free;
	}
	so->size = 4096;

	ret = i915_gem_obj_ggtt_pin(so->obj, 4096, 0);
	if (ret)
		goto free_gem;

	BUG_ON(so->obj->pages->nents != 1);
	page = sg_page(so->obj->pages->sgl);

	so->batch = kmap(page);
	if (!so->batch) {
		ret = -ENOMEM;
		goto unpin;
	}

	so->ggtt_offset = i915_gem_obj_ggtt_offset(so->obj);

	return so;
unpin:
	i915_gem_object_ggtt_unpin(so->obj);
free_gem:
	drm_gem_object_unreference(&so->obj->base);
free:
	kfree(so);
	return ERR_PTR(ret);
}

static void render_state_free(struct i915_render_state *so)
{
	kunmap(kmap_to_page(so->batch));
	i915_gem_object_ggtt_unpin(so->obj);
	drm_gem_object_unreference(&so->obj->base);
	kfree(so);
}

static const struct intel_renderstate_rodata *
render_state_get_rodata(struct drm_device *dev, const int gen)
{
	switch (gen) {
	case 6:
		return &gen6_null_state;
	case 7:
		return &gen7_null_state;
	case 8:
		return &gen8_null_state;
	}

	return NULL;
}

static int render_state_setup(const int gen,
			      const struct intel_renderstate_rodata *rodata,
			      struct i915_render_state *so)
{
	const u64 goffset = i915_gem_obj_ggtt_offset(so->obj);
	u32 reloc_index = 0;
	u32 * const d = so->batch;
	unsigned int i = 0;
	int ret;

	if (!rodata || rodata->batch_items * 4 > so->size)
		return -EINVAL;

	ret = i915_gem_object_set_to_cpu_domain(so->obj, true);
	if (ret)
		return ret;

	while (i < rodata->batch_items) {
		u32 s = rodata->batch[i];

		if (reloc_index < rodata->reloc_items &&
		    i * 4  == rodata->reloc[reloc_index]) {

			s += goffset & 0xffffffff;

			/* We keep batch offsets max 32bit */
			if (gen >= 8) {
				if (i + 1 >= rodata->batch_items ||
				    rodata->batch[i + 1] != 0)
					return -EINVAL;

				d[i] = s;
				i++;
				s = (goffset & 0xffffffff00000000ull) >> 32;
			}

			reloc_index++;
		}

		d[i] = s;
		i++;
	}

	ret = i915_gem_object_set_to_gtt_domain(so->obj, false);
	if (ret)
		return ret;

	if (rodata->reloc_items != reloc_index) {
		DRM_ERROR("not all relocs resolved, %d out of %d\n",
			  reloc_index, rodata->reloc_items);
		return -EINVAL;
	}

	so->len = rodata->batch_items * 4;

	return 0;
}

int i915_gem_render_state_init(struct intel_engine_cs *ring)
{
	const int gen = INTEL_INFO(ring->dev)->gen;
	struct i915_render_state *so;
	const struct intel_renderstate_rodata *rodata;
	int ret;

	if (WARN_ON(ring->id != RCS))
		return -ENOENT;

	rodata = render_state_get_rodata(ring->dev, gen);
	if (rodata == NULL)
		return 0;

	so = render_state_alloc(ring->dev);
	if (IS_ERR(so))
		return PTR_ERR(so);

	ret = render_state_setup(gen, rodata, so);
	if (ret)
		goto out;

	ret = ring->dispatch_execbuffer(ring,
					i915_gem_obj_ggtt_offset(so->obj),
					so->len,
					I915_DISPATCH_SECURE);
	if (ret)
		goto out;

	i915_vma_move_to_active(i915_gem_obj_to_ggtt(so->obj), ring);

	ret = __i915_add_request(ring, NULL, so->obj, NULL);
	/* __i915_add_request moves object to inactive if it fails */
out:
	render_state_free(so);
	return ret;
}