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/*

 * Copyright © 2008-2012 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 

 *    Chris Wilson 

 *

 */

#include 

#include 

#include "i915_drv.h"

/*

 * The BIOS typically reserves some of the system's memory for the exclusive

 * use of the integrated graphics. This memory is no longer available for

 * use by the OS and so the user finds that his system has less memory

 * available than he put in. We refer to this memory as stolen.

 *

 * The BIOS will allocate its framebuffer from the stolen memory. Our

 * goal is try to reuse that object for our own fbcon which must always

 * be available for panics. Anything else we can reuse the stolen memory

 * for is a boon.

 */

static unsigned long i915_stolen_to_physical(struct drm_device *dev)

{

	struct drm_i915_private *dev_priv = dev->dev_private;

	struct resource *r;

	u32 base;

	/* Almost universally we can find the Graphics Base of Stolen Memory

	 * at offset 0x5c in the igfx configuration space. On a few (desktop)

	 * machines this is also mirrored in the bridge device at different

	 * locations, or in the MCHBAR. On gen2, the layout is again slightly

	 * different with the Graphics Segment immediately following Top of

	 * Memory (or Top of Usable DRAM). Note it appears that TOUD is only

	 * reported by 865g, so we just use the top of memory as determined

	 * by the e820 probe.

	 *

	 * XXX However gen2 requires an unavailable symbol.

	 */

	base = 0;

	if (INTEL_INFO(dev)->gen >= 3) {

		/* Read Graphics Base of Stolen Memory directly */

		pci_read_config_dword(dev->pdev, 0x5c, &base);

		base &= ~((1<<20) - 1);

	} else { /* GEN2 */

#if 0

		/* Stolen is immediately above Top of Memory */

		base = max_low_pfn_mapped << PAGE_SHIFT;

#endif

	}

	if (base == 0)

		return 0;

	/* make sure we don't clobber the GTT if it's within stolen memory */

	if (INTEL_INFO(dev)->gen <= 4 && !IS_G33(dev) && !IS_G4X(dev)) {

		struct {

			u32 start, end;

		} stolen[2] = {

			{ .start = base, .end = base + dev_priv->gtt.stolen_size, },

			{ .start = base, .end = base + dev_priv->gtt.stolen_size, },

		};

		u64 gtt_start, gtt_end;

		gtt_start = I915_READ(PGTBL_CTL);

		if (IS_GEN4(dev))

			gtt_start = (gtt_start & PGTBL_ADDRESS_LO_MASK) |

				(gtt_start & PGTBL_ADDRESS_HI_MASK) << 28;

		else

			gtt_start &= PGTBL_ADDRESS_LO_MASK;

		gtt_end = gtt_start + gtt_total_entries(dev_priv->gtt) * 4;

		if (gtt_start >= stolen[0].start && gtt_start < stolen[0].end)

			stolen[0].end = gtt_start;

		if (gtt_end > stolen[1].start && gtt_end <= stolen[1].end)

			stolen[1].start = gtt_end;

		/* pick the larger of the two chunks */

		if (stolen[0].end - stolen[0].start >

		    stolen[1].end - stolen[1].start) {

			base = stolen[0].start;

			dev_priv->gtt.stolen_size = stolen[0].end - stolen[0].start;

		} else {

			base = stolen[1].start;

			dev_priv->gtt.stolen_size = stolen[1].end - stolen[1].start;

		}

		if (stolen[0].start != stolen[1].start ||

		    stolen[0].end != stolen[1].end) {

			DRM_DEBUG_KMS("GTT within stolen memory at 0x%llx-0x%llx\n",

				      (unsigned long long) gtt_start,

				      (unsigned long long) gtt_end - 1);

			DRM_DEBUG_KMS("Stolen memory adjusted to 0x%x-0x%x\n",

				      base, base + (u32) dev_priv->gtt.stolen_size - 1);

		}

	}

#if 0

	/* Verify that nothing else uses this physical address. Stolen

	 * memory should be reserved by the BIOS and hidden from the

	 * kernel. So if the region is already marked as busy, something

	 * is seriously wrong.

	 */

	r = devm_request_mem_region(dev->dev, base, dev_priv->gtt.stolen_size,

				    "Graphics Stolen Memory");

	if (r == NULL) {

		/*

		 * One more attempt but this time requesting region from

		 * base + 1, as we have seen that this resolves the region

		 * conflict with the PCI Bus.

		 * This is a BIOS w/a: Some BIOS wrap stolen in the root

		 * PCI bus, but have an off-by-one error. Hence retry the

		 * reservation starting from 1 instead of 0.

		 */

		r = devm_request_mem_region(dev->dev, base + 1,

					    dev_priv->gtt.stolen_size - 1,

					    "Graphics Stolen Memory");

		/*

		 * GEN3 firmware likes to smash pci bridges into the stolen

		 * range. Apparently this works.

		 */

		if (r == NULL && !IS_GEN3(dev)) {

		DRM_ERROR("conflict detected with stolen region: [0x%08x - 0x%08x]\n",

			  base, base + (uint32_t)dev_priv->gtt.stolen_size);

		base = 0;

	}

	}

#endif

	return base;

}

static int find_compression_threshold(struct drm_device *dev,

				      struct drm_mm_node *node,

				      int size,

				      int fb_cpp)

{

	struct drm_i915_private *dev_priv = dev->dev_private;

	int compression_threshold = 1;

	int ret;

	/* HACK: This code depends on what we will do in *_enable_fbc. If that

	 * code changes, this code needs to change as well.

	 *

	 * The enable_fbc code will attempt to use one of our 2 compression

	 * thresholds, therefore, in that case, we only have 1 resort.

	 */

	/* Try to over-allocate to reduce reallocations and fragmentation. */

	ret = drm_mm_insert_node(&dev_priv->mm.stolen, node,

				 size <<= 1, 4096, DRM_MM_SEARCH_DEFAULT);

	if (ret == 0)

		return compression_threshold;

again:

	/* HW's ability to limit the CFB is 1:4 */

	if (compression_threshold > 4 ||

	    (fb_cpp == 2 && compression_threshold == 2))

		return 0;

	ret = drm_mm_insert_node(&dev_priv->mm.stolen, node,

					 size >>= 1, 4096,

					 DRM_MM_SEARCH_DEFAULT);

	if (ret && INTEL_INFO(dev)->gen <= 4) {

		return 0;

	} else if (ret) {

		compression_threshold <<= 1;

		goto again;

	} else {

		return compression_threshold;

	}

}

static int i915_setup_compression(struct drm_device *dev, int size, int fb_cpp)

{

	struct drm_i915_private *dev_priv = dev->dev_private;

	struct drm_mm_node *uninitialized_var(compressed_llb);

	int ret;

	ret = find_compression_threshold(dev, &dev_priv->fbc.compressed_fb,

					 size, fb_cpp);

	if (!ret)

		goto err_llb;

	else if (ret > 1) {

		DRM_INFO("Reducing the compressed framebuffer size. This may lead to less power savings than a non-reduced-size. Try to increase stolen memory size if available in BIOS.\n");

	}

	dev_priv->fbc.threshold = ret;

	if (HAS_PCH_SPLIT(dev))

		I915_WRITE(ILK_DPFC_CB_BASE, dev_priv->fbc.compressed_fb.start);

	else if (IS_GM45(dev)) {

		I915_WRITE(DPFC_CB_BASE, dev_priv->fbc.compressed_fb.start);

	} else {

		compressed_llb = kzalloc(sizeof(*compressed_llb), GFP_KERNEL);

		if (!compressed_llb)

			goto err_fb;

		ret = drm_mm_insert_node(&dev_priv->mm.stolen, compressed_llb,

					 4096, 4096, DRM_MM_SEARCH_DEFAULT);

		if (ret)

			goto err_fb;

		dev_priv->fbc.compressed_llb = compressed_llb;

		I915_WRITE(FBC_CFB_BASE,

			   dev_priv->mm.stolen_base + dev_priv->fbc.compressed_fb.start);

		I915_WRITE(FBC_LL_BASE,

			   dev_priv->mm.stolen_base + compressed_llb->start);

	}

	dev_priv->fbc.size = size / dev_priv->fbc.threshold;

	DRM_DEBUG_KMS("reserved %d bytes of contiguous stolen space for FBC\n",

		      size);

	return 0;

err_fb:

	kfree(compressed_llb);

	drm_mm_remove_node(&dev_priv->fbc.compressed_fb);

err_llb:

	pr_info_once("drm: not enough stolen space for compressed buffer (need %d more bytes), disabling. Hint: you may be able to increase stolen memory size in the BIOS to avoid this.\n", size);

	return -ENOSPC;

}

int i915_gem_stolen_setup_compression(struct drm_device *dev, int size, int fb_cpp)

{

	struct drm_i915_private *dev_priv = dev->dev_private;

	if (!drm_mm_initialized(&dev_priv->mm.stolen))

		return -ENODEV;

	if (size < dev_priv->fbc.size)

		return 0;

	/* Release any current block */

	i915_gem_stolen_cleanup_compression(dev);

	return i915_setup_compression(dev, size, fb_cpp);

}

void i915_gem_stolen_cleanup_compression(struct drm_device *dev)

{

	struct drm_i915_private *dev_priv = dev->dev_private;

	if (dev_priv->fbc.size == 0)

		return;

	drm_mm_remove_node(&dev_priv->fbc.compressed_fb);

	if (dev_priv->fbc.compressed_llb) {

		drm_mm_remove_node(dev_priv->fbc.compressed_llb);

		kfree(dev_priv->fbc.compressed_llb);

	}

	dev_priv->fbc.size = 0;

}

void i915_gem_cleanup_stolen(struct drm_device *dev)

{

	struct drm_i915_private *dev_priv = dev->dev_private;

	if (!drm_mm_initialized(&dev_priv->mm.stolen))

		return;

	i915_gem_stolen_cleanup_compression(dev);

	drm_mm_takedown(&dev_priv->mm.stolen);

}

int i915_gem_init_stolen(struct drm_device *dev)

{

	struct drm_i915_private *dev_priv = dev->dev_private;

	u32 tmp;

	int bios_reserved = 0;

#ifdef CONFIG_INTEL_IOMMU

	if (intel_iommu_gfx_mapped && INTEL_INFO(dev)->gen < 8) {

		DRM_INFO("DMAR active, disabling use of stolen memory\n");

		return 0;

	}

#endif

	if (dev_priv->gtt.stolen_size == 0)

		return 0;

	dev_priv->mm.stolen_base = i915_stolen_to_physical(dev);

	if (dev_priv->mm.stolen_base == 0)

		return 0;

	DRM_DEBUG_KMS("found %zd bytes of stolen memory at %08lx\n",

		      dev_priv->gtt.stolen_size, dev_priv->mm.stolen_base);

	if (INTEL_INFO(dev)->gen >= 8) {

		tmp = I915_READ(GEN7_BIOS_RESERVED);

		tmp >>= GEN8_BIOS_RESERVED_SHIFT;

		tmp &= GEN8_BIOS_RESERVED_MASK;

		bios_reserved = (1024*1024) << tmp;

	} else if (IS_GEN7(dev)) {

		tmp = I915_READ(GEN7_BIOS_RESERVED);

		bios_reserved = tmp & GEN7_BIOS_RESERVED_256K ?

			256*1024 : 1024*1024;

	}

	if (WARN_ON(bios_reserved > dev_priv->gtt.stolen_size))

		return 0;

	/* Basic memrange allocator for stolen space */

	drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->gtt.stolen_size -

		    bios_reserved);

	return 0;

}

static struct sg_table *

i915_pages_create_for_stolen(struct drm_device *dev,

			     u32 offset, u32 size)

{

	struct drm_i915_private *dev_priv = dev->dev_private;

	struct sg_table *st;

	struct scatterlist *sg;

	DRM_DEBUG_DRIVER("offset=0x%x, size=%d\n", offset, size);

	BUG_ON(offset > dev_priv->gtt.stolen_size - size);

	/* We hide that we have no struct page backing our stolen object

	 * by wrapping the contiguous physical allocation with a fake

	 * dma mapping in a single scatterlist.

	 */

	st = kmalloc(sizeof(*st), GFP_KERNEL);

	if (st == NULL)

		return NULL;

	if (sg_alloc_table(st, 1, GFP_KERNEL)) {

		kfree(st);

		return NULL;

	}

	sg = st->sgl;

	sg->offset = 0;

	sg->length = size;

	sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;

	sg_dma_len(sg) = size;

	return st;

}

static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)

{

	BUG();

	return -EINVAL;

}

static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj)

{

	/* Should only be called during free */

	sg_free_table(obj->pages);

	kfree(obj->pages);

}

static void

i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)

{

	if (obj->stolen) {

		drm_mm_remove_node(obj->stolen);

		kfree(obj->stolen);

		obj->stolen = NULL;

	}

}

static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {

	.get_pages = i915_gem_object_get_pages_stolen,

	.put_pages = i915_gem_object_put_pages_stolen,

	.release = i915_gem_object_release_stolen,

};

static struct drm_i915_gem_object *

_i915_gem_object_create_stolen(struct drm_device *dev,

			       struct drm_mm_node *stolen)

{

	struct drm_i915_gem_object *obj;

	obj = i915_gem_object_alloc(dev);

	if (obj == NULL)

		return NULL;

	drm_gem_private_object_init(dev, &obj->base, stolen->size);

	i915_gem_object_init(obj, &i915_gem_object_stolen_ops);

	obj->pages = i915_pages_create_for_stolen(dev,

						  stolen->start, stolen->size);

	if (obj->pages == NULL)

		goto cleanup;

	obj->has_dma_mapping = true;

	i915_gem_object_pin_pages(obj);

	obj->stolen = stolen;

	obj->base.read_domains = I915_GEM_DOMAIN_CPU | I915_GEM_DOMAIN_GTT;

	obj->cache_level = HAS_LLC(dev) ? I915_CACHE_LLC : I915_CACHE_NONE;

	return obj;

cleanup:

	i915_gem_object_free(obj);

	return NULL;

}

struct drm_i915_gem_object *

i915_gem_object_create_stolen(struct drm_device *dev, u32 size)

{

	struct drm_i915_private *dev_priv = dev->dev_private;

	struct drm_i915_gem_object *obj;

	struct drm_mm_node *stolen;

	int ret;

	if (!drm_mm_initialized(&dev_priv->mm.stolen))

		return NULL;

	DRM_DEBUG_KMS("creating stolen object: size=%x\n", size);

	if (size == 0)

		return NULL;

	stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);

	if (!stolen)

		return NULL;

	ret = drm_mm_insert_node(&dev_priv->mm.stolen, stolen, size,

				 4096, DRM_MM_SEARCH_DEFAULT);

	if (ret) {

		kfree(stolen);

		return NULL;

	}

	obj = _i915_gem_object_create_stolen(dev, stolen);

	if (obj)

		return obj;

	drm_mm_remove_node(stolen);

	kfree(stolen);

	return NULL;

}

struct drm_i915_gem_object *

i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,

					       u32 stolen_offset,

					       u32 gtt_offset,

					       u32 size)

{

	struct drm_i915_private *dev_priv = dev->dev_private;

	struct i915_address_space *ggtt = &dev_priv->gtt.base;

	struct drm_i915_gem_object *obj;

	struct drm_mm_node *stolen;

	struct i915_vma *vma;

	int ret;

	if (!drm_mm_initialized(&dev_priv->mm.stolen))

		return NULL;

	DRM_DEBUG_KMS("creating preallocated stolen object: stolen_offset=%x, gtt_offset=%x, size=%x\n",

			stolen_offset, gtt_offset, size);

	/* KISS and expect everything to be page-aligned */

	BUG_ON(stolen_offset & 4095);

	BUG_ON(size & 4095);

	if (WARN_ON(size == 0))

		return NULL;

	stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);

	if (!stolen)

		return NULL;

	stolen->start = stolen_offset;

	stolen->size = size;

	ret = drm_mm_reserve_node(&dev_priv->mm.stolen, stolen);

	if (ret) {

		DRM_DEBUG_KMS("failed to allocate stolen space\n");

		kfree(stolen);

		return NULL;

	}

	obj = _i915_gem_object_create_stolen(dev, stolen);

	if (obj == NULL) {

		DRM_DEBUG_KMS("failed to allocate stolen object\n");

		drm_mm_remove_node(stolen);

		kfree(stolen);

		return NULL;

	}

	/* Some objects just need physical mem from stolen space */

	if (gtt_offset == I915_GTT_OFFSET_NONE)

		return obj;

	vma = i915_gem_obj_lookup_or_create_vma(obj, ggtt);

	if (IS_ERR(vma)) {

		ret = PTR_ERR(vma);

		goto err_out;

	}

	/* To simplify the initialisation sequence between KMS and GTT,

	 * we allow construction of the stolen object prior to

	 * setting up the GTT space. The actual reservation will occur

	 * later.

	 */

	vma->node.start = gtt_offset;

	vma->node.size = size;

	if (drm_mm_initialized(&ggtt->mm)) {

		ret = drm_mm_reserve_node(&ggtt->mm, &vma->node);

		if (ret) {

			DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");

			goto err_vma;

		}

		}

	vma->bound |= GLOBAL_BIND;

	list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);

	list_add_tail(&vma->mm_list, &ggtt->inactive_list);

	i915_gem_object_pin_pages(obj);

	return obj;

err_vma:

	i915_gem_vma_destroy(vma);

err_out:

	drm_mm_remove_node(stolen);

	kfree(stolen);

	drm_gem_object_unreference(&obj->base);

	return NULL;

}