[PATCHv3/RFC 1/4] drm/arm: Factor out generic afbc helpers

Andrzej Pietrasiewicz andrzej.p at collabora.com
Thu Nov 21 17:22:44 UTC 2019


These are useful for other users of afbc, e.g. rockchip.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p at collabora.com>
---
 drivers/gpu/drm/Makefile          |  2 +-
 drivers/gpu/drm/drm_afbc.c        | 84 +++++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_fourcc.c      | 11 +++-
 drivers/gpu/drm/drm_framebuffer.c | 71 +++++++++++++++++++++++++-
 include/drm/drm_afbc.h            | 35 +++++++++++++
 5 files changed, 199 insertions(+), 4 deletions(-)
 create mode 100644 drivers/gpu/drm/drm_afbc.c
 create mode 100644 include/drm/drm_afbc.h

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index d9bcc9f2a0a4..3a58f30b83a6 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -44,7 +44,7 @@ drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_dsc.o drm_probe_helper
 		drm_simple_kms_helper.o drm_modeset_helper.o \
 		drm_scdc_helper.o drm_gem_framebuffer_helper.o \
 		drm_atomic_state_helper.o drm_damage_helper.o \
-		drm_format_helper.o drm_self_refresh_helper.o
+		drm_format_helper.o drm_self_refresh_helper.o drm_afbc.o
 
 drm_kms_helper-$(CONFIG_DRM_PANEL_BRIDGE) += bridge/panel.o
 drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o
diff --git a/drivers/gpu/drm/drm_afbc.c b/drivers/gpu/drm/drm_afbc.c
new file mode 100644
index 000000000000..f308c4719546
--- /dev/null
+++ b/drivers/gpu/drm/drm_afbc.c
@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) 2019 Collabora Ltd.
+ *
+ * author: Andrzej Pietrasiewicz <andrzej.p at collabora.com>
+ *
+ */
+#include <linux/module.h>
+
+#include <drm/drm_afbc.h>
+#include <drm/drm_device.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_gem.h>
+#include <drm/drm_mode.h>
+#include <drm/drm_print.h>
+
+/**
+ * drm_afbc_get_superblk_wh - extract afbc block width/height from modifier
+ * @modifier: the modifier to be looked at
+ * @w: address of a place to store the block width
+ * @h: address of a place to store the block height
+ *
+ * Returns: true if the modifier describes a supported block size
+ */
+bool drm_afbc_get_superblk_wh(u64 modifier, u32 *w, u32 *h)
+{
+	switch (modifier & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK) {
+	case AFBC_FORMAT_MOD_BLOCK_SIZE_16x16:
+		*w = 16;
+		*h = 16;
+		break;
+	case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8:
+		*w = 32;
+		*h = 8;
+		break;
+	case AFBC_FORMAT_MOD_BLOCK_SIZE_64x4:
+		/* fall through */
+	case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8_64x4:
+		/* fall through */
+	default:
+		DRM_DEBUG_KMS("Invalid AFBC_FORMAT_MOD_BLOCK_SIZE: %lld.\n",
+			      modifier & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK);
+		return false;
+	}
+	return true;
+}
+EXPORT_SYMBOL_GPL(drm_afbc_get_superblk_wh);
+
+/**
+ * drm_afbc_get_parameters - extract afbc parameters from mode command
+ * @mode_cmd: mode command to be looked at
+ * @afbc: address of a struct to be filled in
+ */
+void drm_afbc_get_parameters(const struct drm_mode_fb_cmd2 *mode_cmd,
+			     struct drm_afbc *afbc)
+{
+	drm_afbc_get_superblk_wh(mode_cmd->modifier[0],
+				 &afbc->tile_w, &afbc->tile_h);
+	afbc->width = mode_cmd->pitches[0];
+	afbc->height =
+		DIV_ROUND_UP(mode_cmd->height, afbc->tile_h) * afbc->tile_h;
+	afbc->offset = mode_cmd->offsets[0];
+}
+EXPORT_SYMBOL(drm_afbc_get_parameters);
+
+/**
+ * drm_is_afbc - test if the modifier describes an afbc buffer
+ * @modifier - modifier to be tested
+ *
+ * Returns: true if the modifier describes an afbc buffer
+ */
+bool drm_is_afbc(u64 modifier)
+{
+	/* is it ARM AFBC? */
+	if ((modifier & DRM_FORMAT_MOD_ARM_AFBC(0)) == 0)
+		return false;
+
+	/* Block size must be known */
+	if ((modifier & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK) == 0)
+		return false;
+
+	return true;
+}
+EXPORT_SYMBOL_GPL(drm_is_afbc);
diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index c630064ccf41..8d9f197cc0ab 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -27,6 +27,7 @@
 #include <linux/export.h>
 #include <linux/kernel.h>
 
+#include <drm/drm_afbc.h>
 #include <drm/drm_device.h>
 #include <drm/drm_fourcc.h>
 
@@ -322,8 +323,14 @@ drm_get_format_info(struct drm_device *dev,
 {
 	const struct drm_format_info *info = NULL;
 
-	if (dev->mode_config.funcs->get_format_info)
-		info = dev->mode_config.funcs->get_format_info(mode_cmd);
+	/* bypass driver callback if afbc */
+	if (!drm_is_afbc(mode_cmd->modifier[0]))
+		if (dev->mode_config.funcs->get_format_info) {
+			const struct drm_mode_config_funcs *funcs;
+
+			funcs = dev->mode_config.funcs;
+			info = funcs->get_format_info(mode_cmd);
+		}
 
 	if (!info)
 		info = drm_format_info(mode_cmd->pixel_format);
diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
index 57564318ceea..303eea624a02 100644
--- a/drivers/gpu/drm/drm_framebuffer.c
+++ b/drivers/gpu/drm/drm_framebuffer.c
@@ -23,6 +23,7 @@
 #include <linux/export.h>
 #include <linux/uaccess.h>
 
+#include <drm/drm_afbc.h>
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_uapi.h>
 #include <drm/drm_auth.h>
@@ -31,6 +32,7 @@
 #include <drm/drm_file.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_framebuffer.h>
+#include <drm/drm_gem.h>
 #include <drm/drm_print.h>
 #include <drm/drm_util.h>
 
@@ -168,7 +170,69 @@ static int fb_plane_height(int height,
 	return DIV_ROUND_UP(height, format->vsub);
 }
 
+static int afbc_check(struct drm_file *file_priv,
+		      const struct drm_mode_fb_cmd2 *r, int i,
+		      const struct drm_format_info *info)
+{
+	struct drm_gem_object *obj;
+	int bpp = info->cpp[0] * 8;
+	int tiles;
+	u32 w, h, height, tile_sz, afbc_size;
+	int result = 0;
+
+	if (i) {
+		DRM_DEBUG_KMS("AFBC supported only for plane 0\n");
+
+		return 1;
+	}
+
+	/* get tile w/h */
+	if (!drm_afbc_get_superblk_wh(r->modifier[0], &w, &h))
+		return 1;
+
+	/* pitch must be divisible by tile width */
+	if (r->pitches[0] % w) {
+		DRM_DEBUG_KMS("Invalid pitch for plane %d\n", i);
+
+		return 1;
+	}
+
+	obj = drm_gem_object_lookup(file_priv, r->handles[0]);
+	if (!obj) {
+		DRM_DEBUG_KMS("Failed to lookup GEM object\n");
+
+		return 1;
+	}
+
+	/* estimate height based on tile size and height from userspace */
+	height = DIV_ROUND_UP(r->height, h) * h;
+
+	tiles = (r->pitches[0] / w) * (height / h);
+	afbc_size = ALIGN(tiles * AFBC_HEADER_SIZE, AFBC_SUPERBLK_ALIGNMENT);
+
+	tile_sz = (bpp * w * h) / BITS_PER_BYTE;
+	afbc_size += tiles * ALIGN(tile_sz, AFBC_SUPERBLK_ALIGNMENT);
+
+	result = obj->size < afbc_size;
+
+	drm_gem_object_put_unlocked(obj);
+
+	return result;
+}
+
+static int modifier_check(struct drm_file *file_priv,
+			  const struct drm_mode_fb_cmd2 *r, int i,
+			  const struct drm_format_info *info)
+{
+	/* non-afbc format */
+	if (!drm_is_afbc(r->modifier[i]))
+		return 0;
+
+	return afbc_check(file_priv, r, i, info);
+}
+
 static int framebuffer_check(struct drm_device *dev,
+			     struct drm_file *file_priv,
 			     const struct drm_mode_fb_cmd2 *r)
 {
 	const struct drm_format_info *info;
@@ -204,6 +268,9 @@ static int framebuffer_check(struct drm_device *dev,
 		unsigned int block_size = info->char_per_block[i];
 		u64 min_pitch = drm_format_info_min_pitch(info, i, width);
 
+		if (drm_is_afbc(r->modifier[i]))
+			block_size = 0;
+
 		if (!block_size && (r->modifier[i] == DRM_FORMAT_MOD_LINEAR)) {
 			DRM_DEBUG_KMS("Format requires non-linear modifier for plane %d\n", i);
 			return -EINVAL;
@@ -253,6 +320,8 @@ static int framebuffer_check(struct drm_device *dev,
 			break;
 
 		default:
+			if (modifier_check(file_priv, r, i, info))
+				return -EINVAL;
 			break;
 		}
 	}
@@ -317,7 +386,7 @@ drm_internal_framebuffer_create(struct drm_device *dev,
 		return ERR_PTR(-EINVAL);
 	}
 
-	ret = framebuffer_check(dev, r);
+	ret = framebuffer_check(dev, file_priv, r);
 	if (ret)
 		return ERR_PTR(ret);
 
diff --git a/include/drm/drm_afbc.h b/include/drm/drm_afbc.h
new file mode 100644
index 000000000000..fb4d4549f77e
--- /dev/null
+++ b/include/drm/drm_afbc.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * (C) 2019 Collabora Ltd.
+ *
+ * author: Andrzej Pietrasiewicz <andrzej.p at collabora.com>
+ *
+ */
+#ifndef __DRM_AFBC_H__
+#define __DRM_AFBC_H__
+
+#include <linux/types.h>
+
+struct drm_device;
+struct drm_mode_fb_cmd2;
+struct drm_gem_object;
+
+struct drm_afbc {
+	u32 tile_w;
+	u32 tile_h;
+	u32 width;
+	u32 height;
+	u32 offset;
+};
+
+#define AFBC_HEADER_SIZE		16
+#define AFBC_SUPERBLK_ALIGNMENT		128
+
+bool drm_afbc_get_superblk_wh(u64 modifier, u32 *w, u32 *h);
+
+void drm_afbc_get_parameters(const struct drm_mode_fb_cmd2 *mode_cmd,
+			     struct drm_afbc *afbc);
+
+bool drm_is_afbc(u64 modifier);
+
+#endif /* __DRM_AFBC_H__ */
-- 
2.17.1



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