drm/vc4: Add T-format scanout support.

This allows mesa to set the tiling format for a BO and have that tiling format be respected by mesa on the other side of an import/export (and by vc4 scanout in the kernel), without defining a protocol to pass the tiling through userspace.

Signed-off-by Eric Anholt <[email protected]>

---

igt tests (which caught two edge cases) submitted to intel-gfx.

Mesa code: https://github.com/anholt/mesa/commits/drm-vc4-tiling

 drivers/gpu/drm/vc4/vc4_bo.c  | 83 +++++++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/vc4/vc4_drv.c |  2 ++
 drivers/gpu/drm/vc4/vc4_drv.h |  6 ++++
 drivers/gpu/drm/vc4/vc4_kms.c | 41 ++++++++++++++++++++-
 include/uapi/drm/vc4_drm.h    | 16 +++++++++
 5 files changed, 147 insertions(+), 1 deletion(-)

drivers/gpu/drm/vc4/vc4_bo.c +83 -0

index 80b2f9e55c5c..21649109fd4f 100644
@@ -347,6 +347,7 @@ void vc4_free_object(struct drm_gem_object *gem_bo)
 		bo->validated_shader = NULL;
 	}
 
+	bo->t_format = false;
 	bo->free_time = jiffies;
 	list_add(&bo->size_head, cache_list);
 	list_add(&bo->unref_head, &vc4->bo_cache.time_list);

@@ -572,6 +573,88 @@ vc4_create_shader_bo_ioctl(struct drm_device *dev, void *data,
 	return ret;
 }
 
+/**
+ * vc4_set_tiling_ioctl() - Sets the tiling modifier for a BO.
+ * @dev: DRM device
+ * @data: ioctl argument
+ * @file_priv: DRM file for this fd
+ *
+ * The tiling state of the BO decides the default modifier of an fb if
+ * no specific modifier was set by userspace, and the return value of
+ * vc4_get_tiling_ioctl() (so that userspace can treat a BO it
+ * received from dmabuf as the same tiling format as the producer
+ * used).
+ */
+int vc4_set_tiling_ioctl(struct drm_device *dev, void *data,
+			 struct drm_file *file_priv)
+{
+	struct drm_vc4_set_tiling *args = data;
+	struct drm_gem_object *gem_obj;
+	struct vc4_bo *bo;
+	bool t_format;
+
+	if (args->flags != 0)
+		return -EINVAL;
+
+	switch (args->modifier) {
+	case DRM_FORMAT_MOD_NONE:
+		t_format = false;
+		break;
+	case DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED:
+		t_format = true;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
+	if (!gem_obj) {
+		DRM_ERROR("Failed to look up GEM BO %d\n", args->handle);
+		return -ENOENT;
+	}
+	bo = to_vc4_bo(gem_obj);
+	bo->t_format = t_format;
+
+	drm_gem_object_unreference_unlocked(gem_obj);
+
+	return 0;
+}
+
+/**
+ * vc4_get_tiling_ioctl() - Gets the tiling modifier for a BO.
+ * @dev: DRM device
+ * @data: ioctl argument
+ * @file_priv: DRM file for this fd
+ *
+ * Returns the tiling modifier for a BO as set by vc4_set_tiling_ioctl().
+ */
+int vc4_get_tiling_ioctl(struct drm_device *dev, void *data,
+			 struct drm_file *file_priv)
+{
+	struct drm_vc4_get_tiling *args = data;
+	struct drm_gem_object *gem_obj;
+	struct vc4_bo *bo;
+
+	if (args->flags != 0 || args->modifier != 0)
+		return -EINVAL;
+
+	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
+	if (!gem_obj) {
+		DRM_ERROR("Failed to look up GEM BO %d\n", args->handle);
+		return -ENOENT;
+	}
+	bo = to_vc4_bo(gem_obj);
+
+	if (bo->t_format)
+		args->modifier = DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED;
+	else
+		args->modifier = DRM_FORMAT_MOD_NONE;
+
+	drm_gem_object_unreference_unlocked(gem_obj);
+
+	return 0;
+}
+
 void vc4_bo_cache_init(struct drm_device *dev)
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);

drivers/gpu/drm/vc4/vc4_drv.c +2 -0

index 136bb4213dc0..c6b487c3d2b7 100644
@@ -138,6 +138,8 @@ static const struct drm_ioctl_desc vc4_drm_ioctls[] = {
 	DRM_IOCTL_DEF_DRV(VC4_GET_HANG_STATE, vc4_get_hang_state_ioctl,
 			  DRM_ROOT_ONLY),
 	DRM_IOCTL_DEF_DRV(VC4_GET_PARAM, vc4_get_param_ioctl, DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(VC4_SET_TILING, vc4_set_tiling_ioctl, DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(VC4_GET_TILING, vc4_get_tiling_ioctl, DRM_RENDER_ALLOW),
 };
 
 static struct drm_driver vc4_drm_driver = {

drivers/gpu/drm/vc4/vc4_drv.h +0 -0

index a5bf2e5e0b57..df22698d62ee 100644

drivers/gpu/drm/vc4/vc4_drv.h +4 -0

 	/* List entry for the BO's position in either
 	 * vc4_exec_info->unref_list or vc4_dev->bo_cache.time_list
 	 */

@@ -470,6 +472,10 @@ int vc4_create_shader_bo_ioctl(struct drm_device *dev, void *data,
 			       struct drm_file *file_priv);
 int vc4_mmap_bo_ioctl(struct drm_device *dev, void *data,
 		      struct drm_file *file_priv);
+int vc4_set_tiling_ioctl(struct drm_device *dev, void *data,
+			 struct drm_file *file_priv);
+int vc4_get_tiling_ioctl(struct drm_device *dev, void *data,
+			 struct drm_file *file_priv);
 int vc4_get_hang_state_ioctl(struct drm_device *dev, void *data,
 			     struct drm_file *file_priv);
 int vc4_mmap(struct file *filp, struct vm_area_struct *vma);

drivers/gpu/drm/vc4/vc4_kms.c +40 -1

index 928d191ef90f..202f7ebf5a7b 100644
@@ -202,11 +202,50 @@ static int vc4_atomic_commit(struct drm_device *dev,
 	return 0;
 }
 
+static struct drm_framebuffer *vc4_fb_create(struct drm_device *dev,
+					     struct drm_file *file_priv,
+					     const struct drm_mode_fb_cmd2 *mode_cmd)
+{
+	struct drm_mode_fb_cmd2 mode_cmd_local;
+
+	/* If the user didn't specify a modifier, use the
+	 * vc4_set_tiling_ioctl() state for the BO.
+	 */
+	if (!(mode_cmd->flags & DRM_MODE_FB_MODIFIERS)) {
+		struct drm_gem_object *gem_obj;
+		struct vc4_bo *bo;
+
+		gem_obj = drm_gem_object_lookup(file_priv,
+						mode_cmd->handles[0]);
+		if (!gem_obj) {
+			DRM_ERROR("Failed to look up GEM BO %d\n",
+				  mode_cmd->handles[0]);
+			return ERR_PTR(-ENOENT);
+		}
+		bo = to_vc4_bo(gem_obj);
+
+		mode_cmd_local = *mode_cmd;
+
+		if (bo->t_format) {
+			mode_cmd_local.modifier[0] =
+				DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED;
+		} else {
+			mode_cmd_local.modifier[0] = DRM_FORMAT_MOD_NONE;
+		}
+
+		drm_gem_object_unreference_unlocked(gem_obj);
+
+		mode_cmd = &mode_cmd_local;
+	}
+
+	return drm_fb_cma_create(dev, file_priv, mode_cmd);
+}
+
 static const struct drm_mode_config_funcs vc4_mode_funcs = {
 	.output_poll_changed = vc4_output_poll_changed,
 	.atomic_check = drm_atomic_helper_check,
 	.atomic_commit = vc4_atomic_commit,
-	.fb_create = drm_fb_cma_create,
+	.fb_create = vc4_fb_create,
 };
 
 int vc4_kms_load(struct drm_device *dev)

include/uapi/drm/vc4_drm.h +9 -0

index f07a09016726..6ac4c5c014cb 100644
@@ -38,6 +38,8 @@ extern "C" {
 #define DRM_VC4_CREATE_SHADER_BO                  0x05
 #define DRM_VC4_GET_HANG_STATE                    0x06
 #define DRM_VC4_GET_PARAM                         0x07
+#define DRM_VC4_SET_TILING                        0x08
+#define DRM_VC4_GET_TILING                        0x09
 
 #define DRM_IOCTL_VC4_SUBMIT_CL           DRM_IOWR(DRM_COMMAND_BASE + DRM_VC4_SUBMIT_CL, struct drm_vc4_submit_cl)
 #define DRM_IOCTL_VC4_WAIT_SEQNO          DRM_IOWR(DRM_COMMAND_BASE + DRM_VC4_WAIT_SEQNO, struct drm_vc4_wait_seqno)

@@ -47,6 +49,8 @@ extern "C" {
 #define DRM_IOCTL_VC4_CREATE_SHADER_BO    DRM_IOWR(DRM_COMMAND_BASE + DRM_VC4_CREATE_SHADER_BO, struct drm_vc4_create_shader_bo)
 #define DRM_IOCTL_VC4_GET_HANG_STATE      DRM_IOWR(DRM_COMMAND_BASE + DRM_VC4_GET_HANG_STATE, struct drm_vc4_get_hang_state)
 #define DRM_IOCTL_VC4_GET_PARAM           DRM_IOWR(DRM_COMMAND_BASE + DRM_VC4_GET_PARAM, struct drm_vc4_get_param)
+#define DRM_IOCTL_VC4_SET_TILING          DRM_IOWR(DRM_COMMAND_BASE + DRM_VC4_SET_TILING, struct drm_vc4_set_tiling)
+#define DRM_IOCTL_VC4_GET_TILING          DRM_IOWR(DRM_COMMAND_BASE + DRM_VC4_GET_TILING, struct drm_vc4_get_tiling)
 
 struct drm_vc4_submit_rcl_surface {
 	__u32 hindex; /* Handle index, or ~0 if not present. */

@@ -295,6 +299,18 @@ struct drm_vc4_get_param {
 	__u64 value;
 };
 
+struct drm_vc4_get_tiling {
+	__u32 handle;
+	__u32 flags;
+	__u64 modifier;
+};

Hi Eric,

Quoted 141 lines · On Wed, 7 Jun 2017 17:13:36 -0700 Eric Anholt <[email protected]> wrote:

This allows mesa to set the tiling format for a BO and have that tiling format be respected by mesa on the other side of an import/export (and by vc4 scanout in the kernel), without defining a protocol to pass the tiling through userspace.

Signed-off-by Eric Anholt <[email protected]>

---

igt tests (which caught two edge cases) submitted to intel-gfx.

Mesa code: https://github.com/anholt/mesa/commits/drm-vc4-tiling

 drivers/gpu/drm/vc4/vc4_bo.c  | 83 +++++++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/vc4/vc4_drv.c |  2 ++
 drivers/gpu/drm/vc4/vc4_drv.h |  6 ++++
 drivers/gpu/drm/vc4/vc4_kms.c | 41 ++++++++++++++++++++-
 include/uapi/drm/vc4_drm.h    | 16 +++++++++
 5 files changed, 147 insertions(+), 1 deletion(-)

drivers/gpu/drm/vc4/vc4_bo.c +83 -0

index 80b2f9e55c5c..21649109fd4f 100644
@@ -347,6 +347,7 @@ void vc4_free_object(struct drm_gem_object *gem_bo)
 		bo->validated_shader = NULL;
 	}
 
+	bo->t_format = false;
 	bo->free_time = jiffies;
 	list_add(&bo->size_head, cache_list);
 	list_add(&bo->unref_head, &vc4->bo_cache.time_list);

@@ -572,6 +573,88 @@ vc4_create_shader_bo_ioctl(struct drm_device *dev, void *data,
 	return ret;
 }
 
+/**
+ * vc4_set_tiling_ioctl() - Sets the tiling modifier for a BO.
+ * @dev: DRM device
+ * @data: ioctl argument
+ * @file_priv: DRM file for this fd
+ *
+ * The tiling state of the BO decides the default modifier of an fb if
+ * no specific modifier was set by userspace, and the return value of
+ * vc4_get_tiling_ioctl() (so that userspace can treat a BO it
+ * received from dmabuf as the same tiling format as the producer
+ * used).
+ */
+int vc4_set_tiling_ioctl(struct drm_device *dev, void *data,
+			 struct drm_file *file_priv)
+{
+	struct drm_vc4_set_tiling *args = data;
+	struct drm_gem_object *gem_obj;
+	struct vc4_bo *bo;
+	bool t_format;
+
+	if (args->flags != 0)
+		return -EINVAL;
+
+	switch (args->modifier) {
+	case DRM_FORMAT_MOD_NONE:
+		t_format = false;
+		break;
+	case DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED:
+		t_format = true;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
+	if (!gem_obj) {
+		DRM_ERROR("Failed to look up GEM BO %d\n", args->handle);
+		return -ENOENT;
+	}
+	bo = to_vc4_bo(gem_obj);
+	bo->t_format = t_format;
+
+	drm_gem_object_unreference_unlocked(gem_obj);
+
+	return 0;
+}
+
+/**
+ * vc4_get_tiling_ioctl() - Gets the tiling modifier for a BO.
+ * @dev: DRM device
+ * @data: ioctl argument
+ * @file_priv: DRM file for this fd
+ *
+ * Returns the tiling modifier for a BO as set by vc4_set_tiling_ioctl().
+ */
+int vc4_get_tiling_ioctl(struct drm_device *dev, void *data,
+			 struct drm_file *file_priv)
+{
+	struct drm_vc4_get_tiling *args = data;
+	struct drm_gem_object *gem_obj;
+	struct vc4_bo *bo;
+
+	if (args->flags != 0 || args->modifier != 0)
+		return -EINVAL;
+
+	gem_obj = drm_gem_object_lookup(file_priv, args->handle);
+	if (!gem_obj) {
+		DRM_ERROR("Failed to look up GEM BO %d\n", args->handle);
+		return -ENOENT;
+	}
+	bo = to_vc4_bo(gem_obj);
+
+	if (bo->t_format)
+		args->modifier = DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED;
+	else
+		args->modifier = DRM_FORMAT_MOD_NONE;
+
+	drm_gem_object_unreference_unlocked(gem_obj);
+
+	return 0;
+}
+
 void vc4_bo_cache_init(struct drm_device *dev)
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);

drivers/gpu/drm/vc4/vc4_drv.c +2 -0

index 136bb4213dc0..c6b487c3d2b7 100644
@@ -138,6 +138,8 @@ static const struct drm_ioctl_desc vc4_drm_ioctls[] = {
 	DRM_IOCTL_DEF_DRV(VC4_GET_HANG_STATE, vc4_get_hang_state_ioctl,
 			  DRM_ROOT_ONLY),
 	DRM_IOCTL_DEF_DRV(VC4_GET_PARAM, vc4_get_param_ioctl, DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(VC4_SET_TILING, vc4_set_tiling_ioctl, DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(VC4_GET_TILING, vc4_get_tiling_ioctl, DRM_RENDER_ALLOW),
 };
 
 static struct drm_driver vc4_drm_driver = {

drivers/gpu/drm/vc4/vc4_drv.h +0 -0

index a5bf2e5e0b57..df22698d62ee 100644
@@ -148,6 +148,8 @@ struct vc4_bo {
 	 */
 	uint64_t write_seqno;
 

drivers/gpu/drm/vc4/vc4_drv.h struct vc4_bo { · line 152

Quoted 2 lines

drivers/gpu/drm/vc4/vc4_drv.h +2 -0

+	bool t_format;
+

Will we need the DRM_VC4_SET/GET_TILING ioctls when importing a BO that is using H264 tile mode? If this is the case, we should probably store the modifier directly.

This allows mesa to set the tiling format for a BO and have that tiling format be respected by mesa on the other side of an import/export (and by vc4 scanout in the kernel), without defining a protocol to pass the tiling through userspace.

Hi Eric,

Quoted 4 lines · Eric Anholt

This allows mesa to set the tiling format for a BO and have that tiling format be respected by mesa on the other side of an import/export (and by vc4 scanout in the kernel), without defining a protocol to pass the tiling through userspace.

I posted a DRI3 v1.1 patch series which can advertise and also transit modifiers directly under X11, and have also typed up the support for Wayland which is working just fine with Weston from git. If you implement DRIimage v15 to advertise and import modifiers, then you can transit them for free without a magic-back-channel ioctl. Would that be enough to convince you to drop this series?

Quoted 6 lines · Daniel Stone

I posted a DRI3 v1.1 patch series which can advertise and also transit modifiers directly under X11, and have also typed up the support for Wayland which is working just fine with Weston from git. If you implement DRIimage v15 to advertise and import modifiers, then you can transit them for free without a magic-back-channel ioctl. Would that be enough to convince you to drop this series?

Not really -- this patch is pretty small, and doesn't require updating the entire world.

Quoted 10 lines · Eric Anholt

Quoted 6 lines · Daniel Stone

I posted a DRI3 v1.1 patch series which can advertise and also transit modifiers directly under X11, and have also typed up the support for Wayland which is working just fine with Weston from git. If you implement DRIimage v15 to advertise and import modifiers, then you can transit them for free without a magic-back-channel ioctl. Would that be enough to convince you to drop this series?

Not really -- this patch is pretty small, and doesn't require updating the entire world.

The modifier interface is already landed in mainline for KMS, GBM, and Gallium. It's supported in i965 and freedreno, and Lucas has patches to support it for etnaviv/imx-drm as well.

While I get that the {get,set}_tiling interface is necessary to route around the X11 support not existing until very recently, I'm unhappy that it's now landed in mainline imposing a performance penalty on everyone else (Wayland compositors, Kodi, etc etc), with no way to route around it.

The T tiling format is what V3D uses for textures, with no raster support at all until later revisions of the hardware (and always at a large 3D performance penalty). If we can't scan out V3D's format, then we often need to do a relayout at some stage of the pipeline, either right before texturing from the scanout buffer (common in X11 without a compositor) or between a tiled screen buffer right before scanout (an option I've considered in trying to resolve this inconsistency, but which means needing to use the dirty fb ioctl and having some update policy).

T-format scanout lets us avoid either of those shadow copies, for a massive, obvious performance improvement to X11 window dragging without a compositor. Unfortunately, enabling a compositor to work around the discrepancy has turned out to be too costly in memory consumption for the Raspbian distribution.

Because the HVS operates a scanline at a time, compositing from T does increase the memory bandwidth cost of scanout. On my 1920x1080@32bpp display on a RPi3, we go from about 15% of system memory bandwidth with linear to about 20% with tiled. However, for X11 this still ends up being a huge performance win in active usage.

This patch doesn't yet handle src_x/src_y offsetting within the tiled buffer. However, we fail to do so for untiled buffers already.

Signed-off-by Eric Anholt <[email protected]>

---
 drivers/gpu/drm/vc4/vc4_plane.c | 31 +++++++++++++++++++++++++++----
 drivers/gpu/drm/vc4/vc4_regs.h  | 19 +++++++++++++++++++
 include/uapi/drm/drm_fourcc.h   | 23 ++++++++++++++++++++++-
 3 files changed, 68 insertions(+), 5 deletions(-)

drivers/gpu/drm/vc4/vc4_plane.c +27 -4

index da18dec21696..fa6809d8b0fe 100644
@@ -500,8 +500,8 @@ static int vc4_plane_mode_set(struct drm_plane *plane,
 	u32 ctl0_offset = vc4_state->dlist_count;
 	const struct hvs_format *format = vc4_get_hvs_format(fb->format->format);
 	int num_planes = drm_format_num_planes(format->drm);
-	u32 scl0, scl1;
-	u32 lbm_size;
+	u32 scl0, scl1, pitch0;
+	u32 lbm_size, tiling;
 	unsigned long irqflags;
 	int ret, i;
 

@@ -542,11 +542,31 @@ static int vc4_plane_mode_set(struct drm_plane *plane,
 		scl1 = vc4_get_scl_field(state, 0);
 	}
 
+	switch (fb->modifier) {
+	case DRM_FORMAT_MOD_LINEAR:
+		tiling = SCALER_CTL0_TILING_LINEAR;
+		pitch0 = VC4_SET_FIELD(fb->pitches[0], SCALER_SRC_PITCH);
+		break;
+	case DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED:
+		tiling = SCALER_CTL0_TILING_256B_OR_T;
+
+		pitch0 = (VC4_SET_FIELD(0, SCALER_PITCH0_TILE_Y_OFFSET),
+			  VC4_SET_FIELD(0, SCALER_PITCH0_TILE_WIDTH_L),
+			  VC4_SET_FIELD((vc4_state->src_w[0] + 31) >> 5,
+					SCALER_PITCH0_TILE_WIDTH_R));
+		break;
+	default:
+		DRM_DEBUG_KMS("Unsupported FB tiling flag 0x%16llx",
+			      (long long)fb->modifier);
+		return -EINVAL;
+	}
+
 	/* Control word */
 	vc4_dlist_write(vc4_state,
 			SCALER_CTL0_VALID |
 			(format->pixel_order << SCALER_CTL0_ORDER_SHIFT) |
 			(format->hvs << SCALER_CTL0_PIXEL_FORMAT_SHIFT) |
+			VC4_SET_FIELD(tiling, SCALER_CTL0_TILING) |
 			(vc4_state->is_unity ? SCALER_CTL0_UNITY : 0) |
 			VC4_SET_FIELD(scl0, SCALER_CTL0_SCL0) |
 			VC4_SET_FIELD(scl1, SCALER_CTL0_SCL1));

@@ -600,8 +620,11 @@ static int vc4_plane_mode_set(struct drm_plane *plane,
 	for (i = 0; i < num_planes; i++)
 		vc4_dlist_write(vc4_state, 0xc0c0c0c0);
 
-	/* Pitch word 0/1/2 */
-	for (i = 0; i < num_planes; i++) {
+	/* Pitch word 0 */
+	vc4_dlist_write(vc4_state, pitch0);
+
+	/* Pitch word 1/2 */
+	for (i = 1; i < num_planes; i++) {
 		vc4_dlist_write(vc4_state,
 				VC4_SET_FIELD(fb->pitches[i], SCALER_SRC_PITCH));
 	}

drivers/gpu/drm/vc4/vc4_regs.h +19 -0

index 932093936178..d382c34c1b9e 100644
@@ -709,6 +709,13 @@ enum hvs_pixel_format {
 #define SCALER_CTL0_SIZE_MASK			VC4_MASK(29, 24)
 #define SCALER_CTL0_SIZE_SHIFT			24
 
+#define SCALER_CTL0_TILING_MASK			VC4_MASK(21, 20)
+#define SCALER_CTL0_TILING_SHIFT		20
+#define SCALER_CTL0_TILING_LINEAR		0
+#define SCALER_CTL0_TILING_64B			1
+#define SCALER_CTL0_TILING_128B			2
+#define SCALER_CTL0_TILING_256B_OR_T		3
+
 #define SCALER_CTL0_HFLIP                       BIT(16)
 #define SCALER_CTL0_VFLIP                       BIT(15)
 

@@ -838,7 +845,19 @@ enum hvs_pixel_format {
 #define SCALER_PPF_KERNEL_OFFSET_SHIFT		0
 #define SCALER_PPF_KERNEL_UNCACHED		BIT(31)
 
+/* PITCH0/1/2 fields for raster. */
 #define SCALER_SRC_PITCH_MASK			VC4_MASK(15, 0)
 #define SCALER_SRC_PITCH_SHIFT			0
 
+/* PITCH0 fields for T-tiled. */
+#define SCALER_PITCH0_TILE_WIDTH_L_MASK		VC4_MASK(22, 16)
+#define SCALER_PITCH0_TILE_WIDTH_L_SHIFT	16
+#define SCALER_PITCH0_TILE_LINE_DIR		BIT(15)
+#define SCALER_PITCH0_TILE_INITIAL_LINE_DIR	BIT(14)
+/* Y offset within a tile. */
+#define SCALER_PITCH0_TILE_Y_OFFSET_MASK	VC4_MASK(13, 7)
+#define SCALER_PITCH0_TILE_Y_OFFSET_SHIFT	7
+#define SCALER_PITCH0_TILE_WIDTH_R_MASK		VC4_MASK(6, 0)
+#define SCALER_PITCH0_TILE_WIDTH_R_SHIFT	0
+
 #endif /* VC4_REGS_H */

include/uapi/drm/drm_fourcc.h +15 -1

index 55e301047b3e..7586c46f68bf 100644
@@ -182,6 +182,7 @@ extern "C" {
 #define DRM_FORMAT_MOD_VENDOR_SAMSUNG 0x04
 #define DRM_FORMAT_MOD_VENDOR_QCOM    0x05
 #define DRM_FORMAT_MOD_VENDOR_VIVANTE 0x06
+#define DRM_FORMAT_MOD_VENDOR_BROADCOM 0x07
 /* add more to the end as needed */
 
 #define fourcc_mod_code(vendor, val) \

@@ -306,7 +307,6 @@ extern "C" {
  */
 #define DRM_FORMAT_MOD_VIVANTE_SPLIT_SUPER_TILED fourcc_mod_code(VIVANTE, 4)
 
-
 /* NVIDIA Tegra frame buffer modifiers */
 
 /*

@@ -351,6 +351,27 @@ extern "C" {
  */
 #define NV_FORMAT_MOD_TEGRA_16BX2_BLOCK(v) fourcc_mod_tegra_code(2, v)
 
+/*
+ * Broadcom VC4 "T" format
+ *
+ * This is the primary layout that the V3D GPU can texture from (it
+ * can't do linear).  The T format has:
+ *
+ * - 64b utiles of pixels in a raster-order grid according to cpp.  It's 4x4
+ *   pixels at 32 bit depth.
+ *
+ * - 1k subtiles made of a 4x4 raster-order grid of 64b utiles (so usually
+ *   16x16 pixels).
+ *
+ * - 4k tiles made of a 2x2 grid of 1k subtiles (so usually 32x32 pixels).  On
+ *   even 4k tile rows, they're arranged as (BL, TL, TR, BR), and on odd rows