1 files changed, 440 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_tiling.c b/drivers/gpu/drm/i915/gem/i915_gem_tiling.c
new file mode 100644
index 000000000000..ca0c2f451742
--- /dev/null
+++ b/drivers/gpu/drm/i915/gem/i915_gem_tiling.c
@@ -0,0 +1,440 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2008 Intel Corporation
+ */
+
+#include <linux/string.h>
+#include <linux/bitops.h>
+#include <drm/i915_drm.h>
+
+#include "i915_drv.h"
+#include "i915_gem.h"
+#include "i915_gem_ioctls.h"
+#include "i915_gem_object.h"
+
+/**
+ * DOC: buffer object tiling
+ *
+ * i915_gem_set_tiling_ioctl() and i915_gem_get_tiling_ioctl() 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.
+ */
+
+/**
+ * i915_gem_fence_size - required global GTT size for a fence
+ * @i915: i915 device
+ * @size: object size
+ * @tiling: tiling mode
+ * @stride: tiling stride
+ *
+ * Return the required global GTT size for a fence (view of a tiled object),
+ * taking into account potential fence register mapping.
+ */
+u32 i915_gem_fence_size(struct drm_i915_private *i915,
+			u32 size, unsigned int tiling, unsigned int stride)
+{
+	u32 ggtt_size;
+
+	GEM_BUG_ON(!size);
+
+	if (tiling == I915_TILING_NONE)
+		return size;
+
+	GEM_BUG_ON(!stride);
+
+	if (INTEL_GEN(i915) >= 4) {
+		stride *= i915_gem_tile_height(tiling);
+		GEM_BUG_ON(!IS_ALIGNED(stride, I965_FENCE_PAGE));
+		return roundup(size, stride);
+	}
+
+	/* Previous chips need a power-of-two fence region when tiling */
+	if (IS_GEN(i915, 3))
+		ggtt_size = 1024*1024;
+	else
+		ggtt_size = 512*1024;
+
+	while (ggtt_size < size)
+		ggtt_size <<= 1;
+
+	return ggtt_size;
+}
+
+/**
+ * i915_gem_fence_alignment - required global GTT alignment for a fence
+ * @i915: i915 device
+ * @size: object size
+ * @tiling: tiling mode
+ * @stride: tiling stride
+ *
+ * Return the required global GTT alignment for a fence (a view of a tiled
+ * object), taking into account potential fence register mapping.
+ */
+u32 i915_gem_fence_alignment(struct drm_i915_private *i915, u32 size,
+			     unsigned int tiling, unsigned int stride)
+{
+	GEM_BUG_ON(!size);
+
+	/*
+	 * Minimum alignment is 4k (GTT page size), but might be greater
+	 * if a fence register is needed for the object.
+	 */
+	if (tiling == I915_TILING_NONE)
+		return I915_GTT_MIN_ALIGNMENT;
+
+	if (INTEL_GEN(i915) >= 4)
+		return I965_FENCE_PAGE;
+
+	/*
+	 * Previous chips need to be aligned to the size of the smallest
+	 * fence register that can contain the object.
+	 */
+	return i915_gem_fence_size(i915, size, tiling, stride);
+}
+
+/* Check pitch constriants for all chips & tiling formats */
+static bool
+i915_tiling_ok(struct drm_i915_gem_object *obj,
+	       unsigned int tiling, unsigned int stride)
+{
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+	unsigned int tile_width;
+
+	/* Linear is always fine */
+	if (tiling == I915_TILING_NONE)
+		return true;
+
+	if (tiling > I915_TILING_LAST)
+		return false;
+
+	/* 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_GEN(i915) >= 7) {
+		if (stride / 128 > GEN7_FENCE_MAX_PITCH_VAL)
+			return false;
+	} else if (INTEL_GEN(i915) >= 4) {
+		if (stride / 128 > I965_FENCE_MAX_PITCH_VAL)
+			return false;
+	} else {
+		if (stride > 8192)
+			return false;
+
+		if (!is_power_of_2(stride))
+			return false;
+	}
+
+	if (IS_GEN(i915, 2) ||
+	    (tiling == I915_TILING_Y && HAS_128_BYTE_Y_TILING(i915)))
+		tile_width = 128;
+	else
+		tile_width = 512;
+
+	if (!stride || !IS_ALIGNED(stride, tile_width))
+		return false;
+
+	return true;
+}
+
+static bool i915_vma_fence_prepare(struct i915_vma *vma,
+				   int tiling_mode, unsigned int stride)
+{
+	struct drm_i915_private *i915 = vma->vm->i915;
+	u32 size, alignment;
+
+	if (!i915_vma_is_map_and_fenceable(vma))
+		return true;
+
+	size = i915_gem_fence_size(i915, vma->size, tiling_mode, stride);
+	if (vma->node.size < size)
+		return false;
+
+	alignment = i915_gem_fence_alignment(i915, vma->size, tiling_mode, stride);
+	if (!IS_ALIGNED(vma->node.start, alignment))
+		return false;
+
+	return true;
+}
+
+/* Make the current GTT allocation valid for the change in tiling. */
+static int
+i915_gem_object_fence_prepare(struct drm_i915_gem_object *obj,
+			      int tiling_mode, unsigned int stride)
+{
+	struct i915_vma *vma;
+	int ret;
+
+	if (tiling_mode == I915_TILING_NONE)
+		return 0;
+
+	for_each_ggtt_vma(vma, obj) {
+		if (i915_vma_fence_prepare(vma, tiling_mode, stride))
+			continue;
+
+		ret = i915_vma_unbind(vma);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+int
+i915_gem_object_set_tiling(struct drm_i915_gem_object *obj,
+			   unsigned int tiling, unsigned int stride)
+{
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+	struct i915_vma *vma;
+	int err;
+
+	/* Make sure we don't cross-contaminate obj->tiling_and_stride */
+	BUILD_BUG_ON(I915_TILING_LAST & STRIDE_MASK);
+
+	GEM_BUG_ON(!i915_tiling_ok(obj, tiling, stride));
+	GEM_BUG_ON(!stride ^ (tiling == I915_TILING_NONE));
+	lockdep_assert_held(&i915->drm.struct_mutex);
+
+	if ((tiling | stride) == obj->tiling_and_stride)
+		return 0;
+
+	if (i915_gem_object_is_framebuffer(obj))
+		return -EBUSY;
+
+	/* 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.
+	 */
+
+	err = i915_gem_object_fence_prepare(obj, tiling, stride);
+	if (err)
+		return err;
+
+	i915_gem_object_lock(obj);
+	if (i915_gem_object_is_framebuffer(obj)) {
+		i915_gem_object_unlock(obj);
+		return -EBUSY;
+	}
+
+	/* If the memory has unknown (i.e. varying) swizzling, we pin the
+	 * pages to prevent them being swapped out and causing corruption
+	 * due to the change in swizzling.
+	 */
+	mutex_lock(&obj->mm.lock);
+	if (i915_gem_object_has_pages(obj) &&
+	    obj->mm.madv == I915_MADV_WILLNEED &&
+	    i915->quirks & QUIRK_PIN_SWIZZLED_PAGES) {
+		if (tiling == I915_TILING_NONE) {
+			GEM_BUG_ON(!obj->mm.quirked);
+			__i915_gem_object_unpin_pages(obj);
+			obj->mm.quirked = false;
+		}
+		if (!i915_gem_object_is_tiled(obj)) {
+			GEM_BUG_ON(obj->mm.quirked);
+			__i915_gem_object_pin_pages(obj);
+			obj->mm.quirked = true;
+		}
+	}
+	mutex_unlock(&obj->mm.lock);
+
+	for_each_ggtt_vma(vma, obj) {
+		vma->fence_size =
+			i915_gem_fence_size(i915, vma->size, tiling, stride);
+		vma->fence_alignment =
+			i915_gem_fence_alignment(i915,
+						 vma->size, tiling, stride);
+
+		if (vma->fence)
+			vma->fence->dirty = true;
+	}
+
+	obj->tiling_and_stride = tiling | stride;
+	i915_gem_object_unlock(obj);
+
+	/* Force the fence to be reacquired for GTT access */
+	i915_gem_object_release_mmap(obj);
+
+	/* Try to preallocate memory required to save swizzling on put-pages */
+	if (i915_gem_object_needs_bit17_swizzle(obj)) {
+		if (!obj->bit_17) {
+			obj->bit_17 = bitmap_zalloc(obj->base.size >> PAGE_SHIFT,
+						    GFP_KERNEL);
+		}
+	} else {
+		bitmap_free(obj->bit_17);
+		obj->bit_17 = NULL;
+	}
+
+	return 0;
+}
+
+/**
+ * i915_gem_set_tiling_ioctl - 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_ioctl(struct drm_device *dev, void *data,
+			  struct drm_file *file)
+{
+	struct drm_i915_gem_set_tiling *args = data;
+	struct drm_i915_gem_object *obj;
+	int err;
+
+	obj = i915_gem_object_lookup(file, args->handle);
+	if (!obj)
+		return -ENOENT;
+
+	/*
+	 * The tiling mode of proxy objects is handled by its generator, and
+	 * not allowed to be changed by userspace.
+	 */
+	if (i915_gem_object_is_proxy(obj)) {
+		err = -ENXIO;
+		goto err;
+	}
+
+	if (!i915_tiling_ok(obj, args->tiling_mode, args->stride)) {
+		err = -EINVAL;
+		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 = to_i915(dev)->mm.bit_6_swizzle_x;
+		else
+			args->swizzle_mode = to_i915(dev)->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;
+		}
+	}
+
+	err = mutex_lock_interruptible(&dev->struct_mutex);
+	if (err)
+		goto err;
+
+	err = i915_gem_object_set_tiling(obj, args->tiling_mode, args->stride);
+	mutex_unlock(&dev->struct_mutex);
+
+	/* We have to maintain this existing ABI... */
+	args->stride = i915_gem_object_get_stride(obj);
+	args->tiling_mode = i915_gem_object_get_tiling(obj);
+
+err:
+	i915_gem_object_put(obj);
+	return err;
+}
+
+/**
+ * i915_gem_get_tiling_ioctl - 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_ioctl(struct drm_device *dev, void *data,
+			  struct drm_file *file)
+{
+	struct drm_i915_gem_get_tiling *args = data;
+	struct drm_i915_private *dev_priv = to_i915(dev);
+	struct drm_i915_gem_object *obj;
+	int err = -ENOENT;
+
+	rcu_read_lock();
+	obj = i915_gem_object_lookup_rcu(file, args->handle);
+	if (obj) {
+		args->tiling_mode =
+			READ_ONCE(obj->tiling_and_stride) & TILING_MASK;
+		err = 0;
+	}
+	rcu_read_unlock();
+	if (unlikely(err))
+		return err;
+
+	switch (args->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;
+	default:
+	case I915_TILING_NONE:
+		args->swizzle_mode = I915_BIT_6_SWIZZLE_NONE;
+		break;
+	}
+
+	/* 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;
+
+	return 0;
+}