[net-next-2.6.git] / drivers / gpu / drm / i915 / i915_gem_tiling.c

/*
 * Copyright © 2008 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>
 *
 */

#include "linux/string.h"
#include "linux/bitops.h"
#include "drmP.h"
#include "drm.h"
#include "i915_drm.h"
#include "i915_drv.h"

/** @file i915_gem_tiling.c
 *
 * Support for managing tiling state of buffer objects.
 *
 * The idea behind tiling is to increase cache hit rates by rearranging
 * pixel data so that a group of pixel accesses are in the same cacheline.
 * Performance improvement from doing this on the back/depth buffer are on
 * the order of 30%.
 *
 * Intel architectures make this somewhat more complicated, though, by
 * adjustments made to addressing of data when the memory is in interleaved
 * mode (matched pairs of DIMMS) to improve memory bandwidth.
 * For interleaved memory, the CPU sends every sequential 64 bytes
 * to an alternate memory channel so it can get the bandwidth from both.
 *
 * The GPU also rearranges its accesses for increased bandwidth to interleaved
 * memory, and it matches what the CPU does for non-tiled.  However, when tiled
 * it does it a little differently, since one walks addresses not just in the
 * X direction but also Y.  So, along with alternating channels when bit
 * 6 of the address flips, it also alternates when other bits flip --  Bits 9
 * (every 512 bytes, an X tile scanline) and 10 (every two X tile scanlines)
 * are common to both the 915 and 965-class hardware.
 *
 * The CPU also sometimes XORs in higher bits as well, to improve
 * bandwidth doing strided access like we do so frequently in graphics.  This
 * is called "Channel XOR Randomization" in the MCH documentation.  The result
 * is that the CPU is XORing in either bit 11 or bit 17 to bit 6 of its address
 * decode.
 *
 * All of this bit 6 XORing has an effect on our memory management,
 * as we need to make sure that the 3d driver can correctly address object
 * contents.
 *
 * If we don't have interleaved memory, all tiling is safe and no swizzling is
 * required.
 *
 * When bit 17 is XORed in, we simply refuse to tile at all.  Bit
 * 17 is not just a page offset, so as we page an objet out and back in,
 * individual pages in it will have different bit 17 addresses, resulting in
 * each 64 bytes being swapped with its neighbor!
 *
 * Otherwise, if interleaved, we have to tell the 3d driver what the address
 * swizzling it needs to do is, since it's writing with the CPU to the pages
 * (bit 6 and potentially bit 11 XORed in), and the GPU is reading from the
 * pages (bit 6, 9, and 10 XORed in), resulting in a cumulative bit swizzling
 * required by the CPU of XORing in bit 6, 9, 10, and potentially 11, in order
 * to match what the GPU expects.
 */

/**
 * Detects bit 6 swizzling of address lookup between IGD access and CPU
 * access through main memory.
 */
void
i915_gem_detect_bit_6_swizzle(struct drm_device *dev)
{
	drm_i915_private_t *dev_priv = dev->dev_private;
	uint32_t swizzle_x = I915_BIT_6_SWIZZLE_UNKNOWN;
	uint32_t swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN;

	if (IS_GEN5(dev) || IS_GEN6(dev)) {
		/* On Ironlake whatever DRAM config, GPU always do
		 * same swizzling setup.
		 */
		swizzle_x = I915_BIT_6_SWIZZLE_9_10;
		swizzle_y = I915_BIT_6_SWIZZLE_9;
	} else if (IS_GEN2(dev)) {
		/* As far as we know, the 865 doesn't have these bit 6
		 * swizzling issues.
		 */
		swizzle_x = I915_BIT_6_SWIZZLE_NONE;
		swizzle_y = I915_BIT_6_SWIZZLE_NONE;
	} else if (IS_MOBILE(dev)) {
		uint32_t dcc;

		/* On mobile 9xx chipsets, channel interleave by the CPU is
		 * determined by DCC.  For single-channel, neither the CPU
		 * nor the GPU do swizzling.  For dual channel interleaved,
		 * the GPU's interleave is bit 9 and 10 for X tiled, and bit
		 * 9 for Y tiled.  The CPU's interleave is independent, and
		 * can be based on either bit 11 (haven't seen this yet) or
		 * bit 17 (common).
		 */
		dcc = I915_READ(DCC);
		switch (dcc & DCC_ADDRESSING_MODE_MASK) {
		case DCC_ADDRESSING_MODE_SINGLE_CHANNEL:
		case DCC_ADDRESSING_MODE_DUAL_CHANNEL_ASYMMETRIC:
			swizzle_x = I915_BIT_6_SWIZZLE_NONE;
			swizzle_y = I915_BIT_6_SWIZZLE_NONE;
			break;
		case DCC_ADDRESSING_MODE_DUAL_CHANNEL_INTERLEAVED:
			if (dcc & DCC_CHANNEL_XOR_DISABLE) {
				/* This is the base swizzling by the GPU for
				 * tiled buffers.
				 */
				swizzle_x = I915_BIT_6_SWIZZLE_9_10;
				swizzle_y = I915_BIT_6_SWIZZLE_9;
			} else if ((dcc & DCC_CHANNEL_XOR_BIT_17) == 0) {
				/* Bit 11 swizzling by the CPU in addition. */
				swizzle_x = I915_BIT_6_SWIZZLE_9_10_11;
				swizzle_y = I915_BIT_6_SWIZZLE_9_11;
			} else {
				/* Bit 17 swizzling by the CPU in addition. */
				swizzle_x = I915_BIT_6_SWIZZLE_9_10_17;
				swizzle_y = I915_BIT_6_SWIZZLE_9_17;
			}
			break;
		}
		if (dcc == 0xffffffff) {
			DRM_ERROR("Couldn't read from MCHBAR.  "
				  "Disabling tiling.\n");
			swizzle_x = I915_BIT_6_SWIZZLE_UNKNOWN;
			swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN;
		}
	} else {
		/* The 965, G33, and newer, have a very flexible memory
		 * configuration.  It will enable dual-channel mode
		 * (interleaving) on as much memory as it can, and the GPU
		 * will additionally sometimes enable different bit 6
		 * swizzling for tiled objects from the CPU.
		 *
		 * Here's what I found on the G965:
		 *    slot fill         memory size  swizzling
		 * 0A   0B   1A   1B    1-ch   2-ch
		 * 512  0    0    0     512    0     O
		 * 512  0    512  0     16     1008  X
		 * 512  0    0    512   16     1008  X
		 * 0    512  0    512   16     1008  X
		 * 1024 1024 1024 0     2048   1024  O
		 *
		 * We could probably detect this based on either the DRB
		 * matching, which was the case for the swizzling required in
		 * the table above, or from the 1-ch value being less than
		 * the minimum size of a rank.
		 */
		if (I915_READ16(C0DRB3) != I915_READ16(C1DRB3)) {
			swizzle_x = I915_BIT_6_SWIZZLE_NONE;
			swizzle_y = I915_BIT_6_SWIZZLE_NONE;
		} else {
			swizzle_x = I915_BIT_6_SWIZZLE_9_10;
			swizzle_y = I915_BIT_6_SWIZZLE_9;
		}
	}

	dev_priv->mm.bit_6_swizzle_x = swizzle_x;
	dev_priv->mm.bit_6_swizzle_y = swizzle_y;
}

/* Check pitch constriants for all chips & tiling formats */
bool
i915_tiling_ok(struct drm_device *dev, int stride, int size, int tiling_mode)
{
	int tile_width;

	/* Linear is always fine */
	if (tiling_mode == I915_TILING_NONE)
		return true;

	if (IS_GEN2(dev) ||
	    (tiling_mode == I915_TILING_Y && HAS_128_BYTE_Y_TILING(dev)))
		tile_width = 128;
	else
		tile_width = 512;

	/* check maximum stride & object size */
	if (INTEL_INFO(dev)->gen >= 4) {
		/* i965 stores the end address of the gtt mapping in the fence
		 * reg, so dont bother to check the size */
		if (stride / 128 > I965_FENCE_MAX_PITCH_VAL)
			return false;
	} else {
		if (stride > 8192)
			return false;

		if (IS_GEN3(dev)) {
			if (size > I830_FENCE_MAX_SIZE_VAL << 20)
				return false;
		} else {
			if (size > I830_FENCE_MAX_SIZE_VAL << 19)
				return false;
		}
	}

	/* 965+ just needs multiples of tile width */
	if (INTEL_INFO(dev)->gen >= 4) {
		if (stride & (tile_width - 1))
			return false;
		return true;
	}

	/* Pre-965 needs power of two tile widths */
	if (stride < tile_width)
		return false;

	if (stride & (stride - 1))
		return false;

	return true;
}

bool
i915_gem_object_fence_offset_ok(struct drm_gem_object *obj, int tiling_mode)
{
	struct drm_device *dev = obj->dev;
	struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);

	if (obj_priv->gtt_space == NULL)
		return true;

	if (tiling_mode == I915_TILING_NONE)
		return true;

	if (INTEL_INFO(dev)->gen >= 4)
		return true;

	if (obj_priv->gtt_offset & (obj->size - 1))
		return false;

	if (IS_GEN3(dev)) {
		if (obj_priv->gtt_offset & ~I915_FENCE_START_MASK)
			return false;
	} else {
		if (obj_priv->gtt_offset & ~I830_FENCE_START_MASK)
			return false;
	}

	return true;
}

/**
 * Sets the tiling mode of an object, returning the required swizzling of
 * bit 6 of addresses in the object.
 */
int
i915_gem_set_tiling(struct drm_device *dev, void *data,
		   struct drm_file *file_priv)
{
	struct drm_i915_gem_set_tiling *args = data;
	drm_i915_private_t *dev_priv = dev->dev_private;
	struct drm_gem_object *obj;
	struct drm_i915_gem_object *obj_priv;
	int ret;

	ret = i915_gem_check_is_wedged(dev);
	if (ret)
		return ret;

	obj = drm_gem_object_lookup(dev, file_priv, args->handle);
	if (obj == NULL)
		return -ENOENT;
	obj_priv = to_intel_bo(obj);

	if (!i915_tiling_ok(dev, args->stride, obj->size, args->tiling_mode)) {
		drm_gem_object_unreference_unlocked(obj);
		return -EINVAL;
	}

	if (obj_priv->pin_count) {
		drm_gem_object_unreference_unlocked(obj);
		return -EBUSY;
	}

	if (args->tiling_mode == I915_TILING_NONE) {
		args->swizzle_mode = I915_BIT_6_SWIZZLE_NONE;
		args->stride = 0;
	} else {
		if (args->tiling_mode == I915_TILING_X)
			args->swizzle_mode = dev_priv->mm.bit_6_swizzle_x;
		else
			args->swizzle_mode = dev_priv->mm.bit_6_swizzle_y;

		/* Hide bit 17 swizzling from the user.  This prevents old Mesa
		 * from aborting the application on sw fallbacks to bit 17,
		 * and we use the pread/pwrite bit17 paths to swizzle for it.
		 * If there was a user that was relying on the swizzle
		 * information for drm_intel_bo_map()ed reads/writes this would
		 * break it, but we don't have any of those.
		 */
		if (args->swizzle_mode == I915_BIT_6_SWIZZLE_9_17)
			args->swizzle_mode = I915_BIT_6_SWIZZLE_9;
		if (args->swizzle_mode == I915_BIT_6_SWIZZLE_9_10_17)
			args->swizzle_mode = I915_BIT_6_SWIZZLE_9_10;

		/* If we can't handle the swizzling, make it untiled. */
		if (args->swizzle_mode == I915_BIT_6_SWIZZLE_UNKNOWN) {
			args->tiling_mode = I915_TILING_NONE;
			args->swizzle_mode = I915_BIT_6_SWIZZLE_NONE;
			args->stride = 0;
		}
	}

	mutex_lock(&dev->struct_mutex);
	if (args->tiling_mode != obj_priv->tiling_mode ||
	    args->stride != obj_priv->stride) {
		/* We need to rebind the object if its current allocation
		 * no longer meets the alignment restrictions for its new
		 * tiling mode. Otherwise we can just leave it alone, but
		 * need to ensure that any fence register is cleared.
		 */
		if (!i915_gem_object_fence_offset_ok(obj, args->tiling_mode))
			ret = i915_gem_object_unbind(obj);
		else if (obj_priv->fence_reg != I915_FENCE_REG_NONE)
			ret = i915_gem_object_put_fence_reg(obj, true);
		else
			i915_gem_release_mmap(obj);

		if (ret != 0) {
			args->tiling_mode = obj_priv->tiling_mode;
			args->stride = obj_priv->stride;
			goto err;
		}

		obj_priv->tiling_mode = args->tiling_mode;
		obj_priv->stride = args->stride;
	}
err:
	drm_gem_object_unreference(obj);
	mutex_unlock(&dev->struct_mutex);

	return ret;
}

/**
 * Returns the current tiling mode and required bit 6 swizzling for the object.
 */
int
i915_gem_get_tiling(struct drm_device *dev, void *data,
		   struct drm_file *file_priv)
{
	struct drm_i915_gem_get_tiling *args = data;
	drm_i915_private_t *dev_priv = dev->dev_private;
	struct drm_gem_object *obj;
	struct drm_i915_gem_object *obj_priv;

	obj = drm_gem_object_lookup(dev, file_priv, args->handle);
	if (obj == NULL)
		return -ENOENT;
	obj_priv = to_intel_bo(obj);

	mutex_lock(&dev->struct_mutex);

	args->tiling_mode = obj_priv->tiling_mode;
	switch (obj_priv->tiling_mode) {
	case I915_TILING_X:
		args->swizzle_mode = dev_priv->mm.bit_6_swizzle_x;
		break;
	case I915_TILING_Y:
		args->swizzle_mode = dev_priv->mm.bit_6_swizzle_y;
		break;
	case I915_TILING_NONE:
		args->swizzle_mode = I915_BIT_6_SWIZZLE_NONE;
		break;
	default:
		DRM_ERROR("unknown tiling mode\n");
	}

	/* Hide bit 17 from the user -- see comment in i915_gem_set_tiling */
	if (args->swizzle_mode == I915_BIT_6_SWIZZLE_9_17)
		args->swizzle_mode = I915_BIT_6_SWIZZLE_9;
	if (args->swizzle_mode == I915_BIT_6_SWIZZLE_9_10_17)
		args->swizzle_mode = I915_BIT_6_SWIZZLE_9_10;

	drm_gem_object_unreference(obj);
	mutex_unlock(&dev->struct_mutex);

	return 0;
}

/**
 * Swap every 64 bytes of this page around, to account for it having a new
 * bit 17 of its physical address and therefore being interpreted differently
 * by the GPU.
 */
static void
i915_gem_swizzle_page(struct page *page)
{
	char temp[64];
	char *vaddr;
	int i;

	vaddr = kmap(page);

	for (i = 0; i < PAGE_SIZE; i += 128) {
		memcpy(temp, &vaddr[i], 64);
		memcpy(&vaddr[i], &vaddr[i + 64], 64);
		memcpy(&vaddr[i + 64], temp, 64);
	}

	kunmap(page);
}

void
i915_gem_object_do_bit_17_swizzle(struct drm_gem_object *obj)
{
	struct drm_device *dev = obj->dev;
	drm_i915_private_t *dev_priv = dev->dev_private;
	struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);
	int page_count = obj->size >> PAGE_SHIFT;
	int i;

	if (dev_priv->mm.bit_6_swizzle_x != I915_BIT_6_SWIZZLE_9_10_17)
		return;

	if (obj_priv->bit_17 == NULL)
		return;

	for (i = 0; i < page_count; i++) {
		char new_bit_17 = page_to_phys(obj_priv->pages[i]) >> 17;
		if ((new_bit_17 & 0x1) !=
		    (test_bit(i, obj_priv->bit_17) != 0)) {
			i915_gem_swizzle_page(obj_priv->pages[i]);
			set_page_dirty(obj_priv->pages[i]);
		}
	}
}

void
i915_gem_object_save_bit_17_swizzle(struct drm_gem_object *obj)
{
	struct drm_device *dev = obj->dev;
	drm_i915_private_t *dev_priv = dev->dev_private;
	struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);
	int page_count = obj->size >> PAGE_SHIFT;
	int i;

	if (dev_priv->mm.bit_6_swizzle_x != I915_BIT_6_SWIZZLE_9_10_17)
		return;

	if (obj_priv->bit_17 == NULL) {
		obj_priv->bit_17 = kmalloc(BITS_TO_LONGS(page_count) *
					   sizeof(long), GFP_KERNEL);
		if (obj_priv->bit_17 == NULL) {
			DRM_ERROR("Failed to allocate memory for bit 17 "
				  "record\n");
			return;
		}
	}

	for (i = 0; i < page_count; i++) {
		if (page_to_phys(obj_priv->pages[i]) & (1 << 17))
			__set_bit(i, obj_priv->bit_17);
		else
			__clear_bit(i, obj_priv->bit_17);
	}
}
Commit	Line	Data
673a394b EA	1	/*
	2	* Copyright © 2008 Intel Corporation
	3	*
	4	* Permission is hereby granted, free of charge, to any person obtaining a
	5	* copy of this software and associated documentation files (the "Software"),
	6	* to deal in the Software without restriction, including without limitation
	7	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	8	* and/or sell copies of the Software, and to permit persons to whom the
	9	* Software is furnished to do so, subject to the following conditions:
	10	*
	11	* The above copyright notice and this permission notice (including the next
	12	* paragraph) shall be included in all copies or substantial portions of the
	13	* Software.
	14	*
	15	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	16	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	17	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	18	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	19	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
	20	* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
	21	* IN THE SOFTWARE.
	22	*
	23	* Authors:
	24	* Eric Anholt <eric@anholt.net>
	25	*
	26	*/
	27
280b713b EA	28	#include "linux/string.h"
280b713b EA	29	#include "linux/bitops.h"
673a394b EA	30	#include "drmP.h"
	31	#include "drm.h"
	32	#include "i915_drm.h"
	33	#include "i915_drv.h"
	34
	35	/** @file i915_gem_tiling.c
	36	*
	37	* Support for managing tiling state of buffer objects.
	38	*
	39	* The idea behind tiling is to increase cache hit rates by rearranging
	40	* pixel data so that a group of pixel accesses are in the same cacheline.
	41	* Performance improvement from doing this on the back/depth buffer are on
	42	* the order of 30%.
	43	*
	44	* Intel architectures make this somewhat more complicated, though, by
	45	* adjustments made to addressing of data when the memory is in interleaved
	46	* mode (matched pairs of DIMMS) to improve memory bandwidth.
	47	* For interleaved memory, the CPU sends every sequential 64 bytes
	48	* to an alternate memory channel so it can get the bandwidth from both.
	49	*
	50	* The GPU also rearranges its accesses for increased bandwidth to interleaved
	51	* memory, and it matches what the CPU does for non-tiled. However, when tiled
	52	* it does it a little differently, since one walks addresses not just in the
	53	* X direction but also Y. So, along with alternating channels when bit
	54	* 6 of the address flips, it also alternates when other bits flip -- Bits 9
	55	* (every 512 bytes, an X tile scanline) and 10 (every two X tile scanlines)
	56	* are common to both the 915 and 965-class hardware.
	57	*
	58	* The CPU also sometimes XORs in higher bits as well, to improve
	59	* bandwidth doing strided access like we do so frequently in graphics. This
	60	* is called "Channel XOR Randomization" in the MCH documentation. The result
	61	* is that the CPU is XORing in either bit 11 or bit 17 to bit 6 of its address
	62	* decode.
	63	*
	64	* All of this bit 6 XORing has an effect on our memory management,
	65	* as we need to make sure that the 3d driver can correctly address object
	66	* contents.
	67	*
	68	* If we don't have interleaved memory, all tiling is safe and no swizzling is
	69	* required.
	70	*
	71	* When bit 17 is XORed in, we simply refuse to tile at all. Bit
	72	* 17 is not just a page offset, so as we page an objet out and back in,
	73	* individual pages in it will have different bit 17 addresses, resulting in
	74	* each 64 bytes being swapped with its neighbor!
	75	*
	76	* Otherwise, if interleaved, we have to tell the 3d driver what the address
	77	* swizzling it needs to do is, since it's writing with the CPU to the pages
	78	* (bit 6 and potentially bit 11 XORed in), and the GPU is reading from the
	79	* pages (bit 6, 9, and 10 XORed in), resulting in a cumulative bit swizzling
	80	* required by the CPU of XORing in bit 6, 9, 10, and potentially 11, in order
	81	* to match what the GPU expects.
	82	*/
	83
	84	/**
	85	* Detects bit 6 swizzling of address lookup between IGD access and CPU
	86	* access through main memory.
	87	*/
	88	void
	89	i915_gem_detect_bit_6_swizzle(struct drm_device *dev)
	90	{
	91	drm_i915_private_t *dev_priv = dev->dev_private;
	92	uint32_t swizzle_x = I915_BIT_6_SWIZZLE_UNKNOWN;
	93	uint32_t swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN;
94
f00a3ddf	95	if (IS_GEN5(dev) \|\| IS_GEN6(dev)) {
f2b115e6	96	/* On Ironlake whatever DRAM config, GPU always do
553bd149 ZW	97	* same swizzling setup.
	98	*/
	99	swizzle_x = I915_BIT_6_SWIZZLE_9_10;
	100	swizzle_y = I915_BIT_6_SWIZZLE_9;
a6c45cf0	101	} else if (IS_GEN2(dev)) {
673a394b EA	102	/* As far as we know, the 865 doesn't have these bit 6
	103	* swizzling issues.
	104	*/
	105	swizzle_x = I915_BIT_6_SWIZZLE_NONE;
	106	swizzle_y = I915_BIT_6_SWIZZLE_NONE;
568d9a8f	107	} else if (IS_MOBILE(dev)) {
673a394b EA	108	uint32_t dcc;
673a394b EA	109
568d9a8f EA	110	/* On mobile 9xx chipsets, channel interleave by the CPU is
	111	* determined by DCC. For single-channel, neither the CPU
	112	* nor the GPU do swizzling. For dual channel interleaved,
	113	* the GPU's interleave is bit 9 and 10 for X tiled, and bit
	114	* 9 for Y tiled. The CPU's interleave is independent, and
	115	* can be based on either bit 11 (haven't seen this yet) or
	116	* bit 17 (common).
673a394b EA	117	*/
	118	dcc = I915_READ(DCC);
	119	switch (dcc & DCC_ADDRESSING_MODE_MASK) {
	120	case DCC_ADDRESSING_MODE_SINGLE_CHANNEL:
	121	case DCC_ADDRESSING_MODE_DUAL_CHANNEL_ASYMMETRIC:
	122	swizzle_x = I915_BIT_6_SWIZZLE_NONE;
	123	swizzle_y = I915_BIT_6_SWIZZLE_NONE;
	124	break;
	125	case DCC_ADDRESSING_MODE_DUAL_CHANNEL_INTERLEAVED:
568d9a8f EA	126	if (dcc & DCC_CHANNEL_XOR_DISABLE) {
	127	/* This is the base swizzling by the GPU for
	128	* tiled buffers.
	129	*/
673a394b EA	130	swizzle_x = I915_BIT_6_SWIZZLE_9_10;
673a394b EA	131	swizzle_y = I915_BIT_6_SWIZZLE_9;
568d9a8f EA	132	} else if ((dcc & DCC_CHANNEL_XOR_BIT_17) == 0) {
568d9a8f EA	133	/* Bit 11 swizzling by the CPU in addition. */
673a394b EA	134	swizzle_x = I915_BIT_6_SWIZZLE_9_10_11;
	135	swizzle_y = I915_BIT_6_SWIZZLE_9_11;
	136	} else {
568d9a8f	137	/* Bit 17 swizzling by the CPU in addition. */
280b713b EA	138	swizzle_x = I915_BIT_6_SWIZZLE_9_10_17;
280b713b EA	139	swizzle_y = I915_BIT_6_SWIZZLE_9_17;
673a394b EA	140	}
	141	break;
	142	}
	143	if (dcc == 0xffffffff) {
	144	DRM_ERROR("Couldn't read from MCHBAR. "
	145	"Disabling tiling.\n");
	146	swizzle_x = I915_BIT_6_SWIZZLE_UNKNOWN;
	147	swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN;
	148	}
	149	} else {
	150	/* The 965, G33, and newer, have a very flexible memory
	151	* configuration. It will enable dual-channel mode
	152	* (interleaving) on as much memory as it can, and the GPU
	153	* will additionally sometimes enable different bit 6
	154	* swizzling for tiled objects from the CPU.
	155	*
	156	* Here's what I found on the G965:
	157	* slot fill memory size swizzling
	158	* 0A 0B 1A 1B 1-ch 2-ch
	159	* 512 0 0 0 512 0 O
	160	* 512 0 512 0 16 1008 X
	161	* 512 0 0 512 16 1008 X
	162	* 0 512 0 512 16 1008 X
	163	* 1024 1024 1024 0 2048 1024 O
	164	*
	165	* We could probably detect this based on either the DRB
	166	* matching, which was the case for the swizzling required in
	167	* the table above, or from the 1-ch value being less than
	168	* the minimum size of a rank.
	169	*/
	170	if (I915_READ16(C0DRB3) != I915_READ16(C1DRB3)) {
	171	swizzle_x = I915_BIT_6_SWIZZLE_NONE;
	172	swizzle_y = I915_BIT_6_SWIZZLE_NONE;
	173	} else {
	174	swizzle_x = I915_BIT_6_SWIZZLE_9_10;
	175	swizzle_y = I915_BIT_6_SWIZZLE_9;
	176	}
	177	}
	178
	179	dev_priv->mm.bit_6_swizzle_x = swizzle_x;
	180	dev_priv->mm.bit_6_swizzle_y = swizzle_y;
	181	}
	182
0f973f27	183	/* Check pitch constriants for all chips & tiling formats */
76446cac	184	bool
0f973f27 JB	185	i915_tiling_ok(struct drm_device *dev, int stride, int size, int tiling_mode)
	186	{
	187	int tile_width;
	188
	189	/* Linear is always fine */
	190	if (tiling_mode == I915_TILING_NONE)
	191	return true;
	192
a6c45cf0	193	if (IS_GEN2(dev) \|\|
e76a16de	194	(tiling_mode == I915_TILING_Y && HAS_128_BYTE_Y_TILING(dev)))
0f973f27 JB	195	tile_width = 128;
	196	else
	197	tile_width = 512;
	198
8d7773a3	199	/* check maximum stride & object size */
a6c45cf0	200	if (INTEL_INFO(dev)->gen >= 4) {
8d7773a3 DV	201	/* i965 stores the end address of the gtt mapping in the fence
	202	* reg, so dont bother to check the size */
	203	if (stride / 128 > I965_FENCE_MAX_PITCH_VAL)
	204	return false;
a6c45cf0	205	} else {
c36a2a6d	206	if (stride > 8192)
8d7773a3	207	return false;
e76a16de	208
c36a2a6d DV	209	if (IS_GEN3(dev)) {
	210	if (size > I830_FENCE_MAX_SIZE_VAL << 20)
	211	return false;
	212	} else {
	213	if (size > I830_FENCE_MAX_SIZE_VAL << 19)
	214	return false;
	215	}
8d7773a3 DV	216	}
8d7773a3 DV	217
0f973f27	218	/* 965+ just needs multiples of tile width */
a6c45cf0	219	if (INTEL_INFO(dev)->gen >= 4) {
0f973f27 JB	220	if (stride & (tile_width - 1))
	221	return false;
	222	return true;
	223	}
	224
	225	/* Pre-965 needs power of two tile widths */
	226	if (stride < tile_width)
	227	return false;
	228
	229	if (stride & (stride - 1))
	230	return false;
	231
0f973f27 JB	232	return true;
	233	}
	234
f590d279	235	bool
52dc7d32 CW	236	i915_gem_object_fence_offset_ok(struct drm_gem_object *obj, int tiling_mode)
	237	{
	238	struct drm_device *dev = obj->dev;
23010e43	239	struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);
52dc7d32 CW	240
	241	if (obj_priv->gtt_space == NULL)
	242	return true;
	243
	244	if (tiling_mode == I915_TILING_NONE)
	245	return true;
	246
a6c45cf0 CW	247	if (INTEL_INFO(dev)->gen >= 4)
	248	return true;
	249
	250	if (obj_priv->gtt_offset & (obj->size - 1))
	251	return false;
	252
	253	if (IS_GEN3(dev)) {
	254	if (obj_priv->gtt_offset & ~I915_FENCE_START_MASK)
	255	return false;
	256	} else {
	257	if (obj_priv->gtt_offset & ~I830_FENCE_START_MASK)
52dc7d32	258	return false;
52dc7d32 CW	259	}
	260
	261	return true;
	262	}
	263
673a394b EA	264	/**
	265	* Sets the tiling mode of an object, returning the required swizzling of
	266	* bit 6 of addresses in the object.
	267	*/
	268	int
	269	i915_gem_set_tiling(struct drm_device dev, void data,
	270	struct drm_file *file_priv)
	271	{
	272	struct drm_i915_gem_set_tiling *args = data;
	273	drm_i915_private_t *dev_priv = dev->dev_private;
	274	struct drm_gem_object *obj;
	275	struct drm_i915_gem_object *obj_priv;
30dbf0c0 CW	276	int ret;
	277
	278	ret = i915_gem_check_is_wedged(dev);
	279	if (ret)
	280	return ret;
673a394b EA	281
	282	obj = drm_gem_object_lookup(dev, file_priv, args->handle);
	283	if (obj == NULL)
bf79cb91	284	return -ENOENT;
23010e43	285	obj_priv = to_intel_bo(obj);
673a394b	286
72daad40	287	if (!i915_tiling_ok(dev, args->stride, obj->size, args->tiling_mode)) {
bc9025bd	288	drm_gem_object_unreference_unlocked(obj);
0f973f27	289	return -EINVAL;
72daad40	290	}
0f973f27	291
31770bd4 DV	292	if (obj_priv->pin_count) {
	293	drm_gem_object_unreference_unlocked(obj);
	294	return -EBUSY;
	295	}
	296
673a394b	297	if (args->tiling_mode == I915_TILING_NONE) {
673a394b	298	args->swizzle_mode = I915_BIT_6_SWIZZLE_NONE;
52dc7d32	299	args->stride = 0;
673a394b EA	300	} else {
	301	if (args->tiling_mode == I915_TILING_X)
	302	args->swizzle_mode = dev_priv->mm.bit_6_swizzle_x;
	303	else
	304	args->swizzle_mode = dev_priv->mm.bit_6_swizzle_y;
280b713b EA	305
	306	/* Hide bit 17 swizzling from the user. This prevents old Mesa
	307	* from aborting the application on sw fallbacks to bit 17,
	308	* and we use the pread/pwrite bit17 paths to swizzle for it.
	309	* If there was a user that was relying on the swizzle
	310	* information for drm_intel_bo_map()ed reads/writes this would
	311	* break it, but we don't have any of those.
	312	*/
	313	if (args->swizzle_mode == I915_BIT_6_SWIZZLE_9_17)
	314	args->swizzle_mode = I915_BIT_6_SWIZZLE_9;
	315	if (args->swizzle_mode == I915_BIT_6_SWIZZLE_9_10_17)
	316	args->swizzle_mode = I915_BIT_6_SWIZZLE_9_10;
	317
673a394b EA	318	/* If we can't handle the swizzling, make it untiled. */
	319	if (args->swizzle_mode == I915_BIT_6_SWIZZLE_UNKNOWN) {
	320	args->tiling_mode = I915_TILING_NONE;
	321	args->swizzle_mode = I915_BIT_6_SWIZZLE_NONE;
52dc7d32	322	args->stride = 0;
673a394b EA	323	}
673a394b EA	324	}
0f973f27	325
52dc7d32 CW	326	mutex_lock(&dev->struct_mutex);
	327	if (args->tiling_mode != obj_priv->tiling_mode \|\|
	328	args->stride != obj_priv->stride) {
	329	/* We need to rebind the object if its current allocation
	330	* no longer meets the alignment restrictions for its new
	331	* tiling mode. Otherwise we can just leave it alone, but
	332	* need to ensure that any fence register is cleared.
0f973f27	333	*/
52dc7d32	334	if (!i915_gem_object_fence_offset_ok(obj, args->tiling_mode))
fe305198 DV	335	ret = i915_gem_object_unbind(obj);
fe305198 DV	336	else if (obj_priv->fence_reg != I915_FENCE_REG_NONE)
2cf34d7b	337	ret = i915_gem_object_put_fence_reg(obj, true);
52dc7d32	338	else
fe305198 DV	339	i915_gem_release_mmap(obj);
fe305198 DV	340
0f973f27	341	if (ret != 0) {
0f973f27	342	args->tiling_mode = obj_priv->tiling_mode;
52dc7d32 CW	343	args->stride = obj_priv->stride;
52dc7d32 CW	344	goto err;
0f973f27	345	}
52dc7d32	346
0f973f27	347	obj_priv->tiling_mode = args->tiling_mode;
52dc7d32	348	obj_priv->stride = args->stride;
0f973f27	349	}
52dc7d32	350	err:
673a394b	351	drm_gem_object_unreference(obj);
d6873102	352	mutex_unlock(&dev->struct_mutex);
673a394b	353
52dc7d32	354	return ret;
673a394b EA	355	}
	356
	357	/**
	358	* Returns the current tiling mode and required bit 6 swizzling for the object.
	359	*/
	360	int
	361	i915_gem_get_tiling(struct drm_device dev, void data,
	362	struct drm_file *file_priv)
	363	{
	364	struct drm_i915_gem_get_tiling *args = data;
	365	drm_i915_private_t *dev_priv = dev->dev_private;
	366	struct drm_gem_object *obj;
	367	struct drm_i915_gem_object *obj_priv;
	368
	369	obj = drm_gem_object_lookup(dev, file_priv, args->handle);
	370	if (obj == NULL)
bf79cb91	371	return -ENOENT;
23010e43	372	obj_priv = to_intel_bo(obj);
673a394b EA	373
	374	mutex_lock(&dev->struct_mutex);
	375
	376	args->tiling_mode = obj_priv->tiling_mode;
	377	switch (obj_priv->tiling_mode) {
	378	case I915_TILING_X:
	379	args->swizzle_mode = dev_priv->mm.bit_6_swizzle_x;
	380	break;
	381	case I915_TILING_Y:
	382	args->swizzle_mode = dev_priv->mm.bit_6_swizzle_y;
	383	break;
	384	case I915_TILING_NONE:
	385	args->swizzle_mode = I915_BIT_6_SWIZZLE_NONE;
	386	break;
	387	default:
	388	DRM_ERROR("unknown tiling mode\n");
	389	}
	390
280b713b EA	391	/* Hide bit 17 from the user -- see comment in i915_gem_set_tiling */
	392	if (args->swizzle_mode == I915_BIT_6_SWIZZLE_9_17)
	393	args->swizzle_mode = I915_BIT_6_SWIZZLE_9;
	394	if (args->swizzle_mode == I915_BIT_6_SWIZZLE_9_10_17)
	395	args->swizzle_mode = I915_BIT_6_SWIZZLE_9_10;
	396
673a394b	397	drm_gem_object_unreference(obj);
d6873102	398	mutex_unlock(&dev->struct_mutex);
673a394b EA	399
	400	return 0;
	401	}
280b713b EA	402
	403	/**
	404	* Swap every 64 bytes of this page around, to account for it having a new
	405	* bit 17 of its physical address and therefore being interpreted differently
	406	* by the GPU.
	407	*/
dd2575ff	408	static void
280b713b EA	409	i915_gem_swizzle_page(struct page *page)
280b713b EA	410	{
dd2575ff	411	char temp[64];
280b713b EA	412	char *vaddr;
280b713b EA	413	int i;
280b713b EA	414
280b713b EA	415	vaddr = kmap(page);
280b713b EA	416
	417	for (i = 0; i < PAGE_SIZE; i += 128) {
	418	memcpy(temp, &vaddr[i], 64);
	419	memcpy(&vaddr[i], &vaddr[i + 64], 64);
	420	memcpy(&vaddr[i + 64], temp, 64);
	421	}
	422
	423	kunmap(page);
280b713b EA	424	}
	425
	426	void
	427	i915_gem_object_do_bit_17_swizzle(struct drm_gem_object *obj)
	428	{
	429	struct drm_device *dev = obj->dev;
	430	drm_i915_private_t *dev_priv = dev->dev_private;
23010e43	431	struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);
280b713b EA	432	int page_count = obj->size >> PAGE_SHIFT;
	433	int i;
	434
	435	if (dev_priv->mm.bit_6_swizzle_x != I915_BIT_6_SWIZZLE_9_10_17)
	436	return;
	437
	438	if (obj_priv->bit_17 == NULL)
	439	return;
	440
	441	for (i = 0; i < page_count; i++) {
	442	char new_bit_17 = page_to_phys(obj_priv->pages[i]) >> 17;
	443	if ((new_bit_17 & 0x1) !=
	444	(test_bit(i, obj_priv->bit_17) != 0)) {
dd2575ff	445	i915_gem_swizzle_page(obj_priv->pages[i]);
280b713b EA	446	set_page_dirty(obj_priv->pages[i]);
	447	}
	448	}
	449	}
	450
	451	void
	452	i915_gem_object_save_bit_17_swizzle(struct drm_gem_object *obj)
	453	{
	454	struct drm_device *dev = obj->dev;
	455	drm_i915_private_t *dev_priv = dev->dev_private;
23010e43	456	struct drm_i915_gem_object *obj_priv = to_intel_bo(obj);
280b713b EA	457	int page_count = obj->size >> PAGE_SHIFT;
	458	int i;
	459
	460	if (dev_priv->mm.bit_6_swizzle_x != I915_BIT_6_SWIZZLE_9_10_17)
	461	return;
	462
	463	if (obj_priv->bit_17 == NULL) {
	464	obj_priv->bit_17 = kmalloc(BITS_TO_LONGS(page_count) *
	465	sizeof(long), GFP_KERNEL);
	466	if (obj_priv->bit_17 == NULL) {
	467	DRM_ERROR("Failed to allocate memory for bit 17 "
	468	"record\n");
	469	return;
	470	}
	471	}
	472
	473	for (i = 0; i < page_count; i++) {
	474	if (page_to_phys(obj_priv->pages[i]) & (1 << 17))
	475	__set_bit(i, obj_priv->bit_17);
	476	else
	477	__clear_bit(i, obj_priv->bit_17);
	478	}
	479	}