/*
* 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 <drm/drmP.h>
#include <drm/i915_drm.h>
#include "i915_drv.h"
/**
* DOC: buffer object tiling
*
* i915_gem_set_tiling() and i915_gem_get_tiling() is the userspace interface to
* declare fence register requirements.
*
* In principle GEM doesn't care at all about the internal data layout of an
* object, and hence it also doesn't care about tiling or swizzling. There's two
* exceptions:
*
* - For X and Y tiling the hardware provides detilers for CPU access, so called
* fences. Since there's only a limited amount of them the kernel must manage
* these, and therefore userspace must tell the kernel the object tiling if it
* wants to use fences for detiling.
* - On gen3 and gen4 platforms have a swizzling pattern for tiled objects which
* depends upon the physical page frame number. When swapping such objects the
* page frame number might change and the kernel must be able to fix this up
* and hence now the tiling. Note that on a subset of platforms with
* asymmetric memory channel population the swizzling pattern changes in an
* unknown way, and for those the kernel simply forbids swapping completely.
*
* Since neither of this applies for new tiling layouts on modern platforms like
* W, Ys and Yf tiling GEM only allows object tiling to be set to X or Y tiled.
* Anything else can be handled in userspace entirely without the kernel's
* invovlement.
*/
/* Check pitch constriants for all chips & tiling formats */
static 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 */
/* i965+ stores the end address of the gtt mapping in the fence
* reg, so dont bother to check the size */
if (INTEL_INFO(dev)->gen >= 7) {
if (stride / 128 > GEN7_FENCE_MAX_PITCH_VAL)
return false;
} else if (INTEL_INFO(dev)->gen >= 4) {
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;
}
}
if (stride < tile_width)
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 & (stride - 1))
return false;
return true;
}
/* Is the current GTT allocation valid for the change in tiling? */
static bool
i915_gem_object_fence_ok(struct drm_i915_gem_object *obj, int tiling_mode)
{
u32 size;
if (tiling_mode == I915_TILING_NONE)
return true;
if (INTEL_INFO(obj->base.dev)->gen >= 4)
return true;
if (INTEL_INFO(obj->base.dev)->gen == 3) {
if (i915_gem_obj_ggtt_offset(obj) & ~I915_FENCE_START_MASK)
return false;
} else {
if (i915_gem_obj_ggtt_offset(obj) & ~I830_FENCE_START_MASK)
return false;
}
size = i915_gem_get_gtt_size(obj->base.dev, obj->base.size, tiling_mode);
if (i915_gem_obj_ggtt_size(obj) != size)
return false;
if (i915_gem_obj_ggtt_offset(obj) & (size - 1))
return false;
return true;
}
/**
* i915_gem_set_tiling - IOCTL handler to set tiling mode
* @dev: DRM device
* @data: data pointer for the ioctl
* @file: DRM file for the ioctl call
*
* Sets the tiling mode of an object, returning the required swizzling of
* bit 6 of addresses in the object.
*
* Called by the user via ioctl.
*
* Returns:
* Zero on success, negative errno on failure.
*/
int
i915_gem_set_tiling(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_gem_set_tiling *args = data;
struct drm_i915_private *dev_priv = dev->dev_private;
struct drm_i915_gem_object *obj;
int ret = 0;
obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
if (&obj->base == NULL)
return -ENOENT;
if (!i915_tiling_ok(dev,
args->stride, obj->base.size, args->tiling_mode)) {
drm_gem_object_unreference_unlocked(&obj->base);
return -EINVAL;
}
mutex_lock(&dev->struct_mutex);
if (obj->pin_display || obj->framebuffer_references) {
ret = -EBUSY;
goto err;
}
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;
}
}
if (args->tiling_mode != obj->tiling_mode ||
args->stride != obj->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 updated before
* the next fenced (either through the GTT or by the BLT unit
* on older GPUs) access.
*
* After updating the tiling parameters, we then flag whether
* we need to update an associated fence register. Note this
* has to also include the unfenced register the GPU uses
* whilst executing a fenced command for an untiled object.
*/
if (obj->map_and_fenceable &&
!i915_gem_object_fence_ok(obj, args->tiling_mode))
ret = i915_gem_object_ggtt_unbind(obj);
if (ret == 0) {
if (obj->pages &&
obj->madv == I915_MADV_WILLNEED &&
dev_priv->quirks & QUIRK_PIN_SWIZZLED_PAGES) {
if (args->tiling_mode == I915_TILING_NONE)
i915_gem_object_unpin_pages(obj);
if (obj->tiling_mode == I915_TILING_NONE)
i915_gem_object_pin_pages(obj);
}
obj->fence_dirty =
obj->last_fenced_req ||
obj->fence_reg != I915_FENCE_REG_NONE;
obj->tiling_mode = args->tiling_mode;
obj->stride = args->stride;
/* Force the fence to be reacquired for GTT access */
i915_gem_release_mmap(obj);
}
}
/* we have to maintain this existing ABI... */
args->stride = obj->stride;
args->tiling_mode = obj->tiling_mode;
/* Try to preallocate memory required to save swizzling on put-pages */
if (i915_gem_object_needs_bit17_swizzle(obj)) {
if (obj->bit_17 == NULL) {
obj->bit_17 = kcalloc(BITS_TO_LONGS(obj->base.size >> PAGE_SHIFT),
sizeof(long), GFP_KERNEL);
}
} else {
kfree(obj->bit_17);
obj->bit_17 = NULL;
}
err:
drm_gem_object_unreference(&obj->base);
mutex_unlock(&dev->struct_mutex);
return ret;
}
/**
* i915_gem_get_tiling - IOCTL handler to get tiling mode
* @dev: DRM device
* @data: data pointer for the ioctl
* @file: DRM file for the ioctl call
*
* Returns the current tiling mode and required bit 6 swizzling for the object.
*
* Called by the user via ioctl.
*
* Returns:
* Zero on success, negative errno on failure.
*/
int
i915_gem_get_tiling(struct drm_device *dev, void *data,
struct drm_file *file)
{
struct drm_i915_gem_get_tiling *args = data;
struct drm_i915_private *dev_priv = dev->dev_private;
struct drm_i915_gem_object *obj;
obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
if (&obj->base == NULL)
return -ENOENT;
mutex_lock(&dev->struct_mutex);
args->tiling_mode = obj->tiling_mode;
switch (obj->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 (dev_priv->quirks & QUIRK_PIN_SWIZZLED_PAGES)
args->phys_swizzle_mode = I915_BIT_6_SWIZZLE_UNKNOWN;
else
args->phys_swizzle_mode = args->swizzle_mode;
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->base);
mutex_unlock(&dev->struct_mutex);
return 0;
}