[PATCH v7 0/7] drm/log: Introduce a new boot logger to draw the kmsg on the screen

[PATCH v7 0/7] drm/log: Introduce a new boot logger to draw the kmsg on the screen

[Jocelyn Falempe]

drm_log is a simple logger that uses the drm_client API to print the kmsg boot log on the screen.
This is not a full replacement to fbcon, as it will only print the kmsg.
It will never handle user input, or a terminal because this is better done in userspace.

If you're curious on how it looks like, I've put a small demo here:
https://people.redhat.com/jfalempe/drm_log/drm_log_draft_boot_v2.mp4

Design decisions:
  * It uses the drm_client API, so it should work on all drm drivers from the start.
  * It doesn't scroll the message, that way it doesn't need to redraw the whole screen for each new message.
    It also means it doesn't have to keep drawn messages in memory, to redraw them when scrolling.
  * It uses the new non-blocking console API, so it should work well with PREEMPT_RT
 
v2:
 * Use vmap_local() api, with that change, I've tested it successfully on simpledrm, virtio-gpu, amdgpu, and nouveau.
 * Stop drawing when the drm_master is taken. This avoid wasting CPU cycle if the buffer is not visible.
 * Use deferred probe. Only do the probe the first time there is a log to draw. With this, if you boot with quiet, drm_log won't do any modeset.
 * Add color support for the timestamp prefix, like what dmesg does.
 * Add build dependency on  disabling the fbdev emulation, as they are both drm_client, and there is no way to choose which one gets the focus.

v3:
 * Remove the work thread and circular buffer, and use the new write_thread() console API.
 * Register a console for each drm driver.

v4:
 * Can be built as a module, even if that's not really useful.
 * Rebased on top of "drm: Introduce DRM client library" series from Thomas Zimmermann.
 * Add a Kconfig menu to choose between drm client.
 * Add suspend/resume callbacks.
 * Add integer scaling support.
 
v5:
 * Build drm_log in drm_client_lib module, to avoid circular dependency.
 * Export drm_draw symbols, so they can be used if drm_client_lib is built as module.
 * Change scale parameter to unsigned int (Jani Nikula)

v6:
 * Use console_stop() and console_start() in the suspend/resume callback (Petr Mladek).
 * rebase and solve conflict with "drm/panic: Add ABGR2101010 support"

v7:
 * Add a patch fix a build issue due to missing DRM_CLIENT_LIB, reported by kernel test bot.

Jocelyn Falempe (7):
  drm/panic: Move drawing functions to drm_draw
  drm/client: Always select DRM_CLIENT_LIB
  drm/log: Introduce a new boot logger to draw the kmsg on the screen
  drm/log: Do not draw if drm_master is taken
  drm/log: Color the timestamp, to improve readability
  drm/log: Implement suspend/resume
  drm/log: Add integer scaling support

 drivers/gpu/drm/Kconfig            |  53 +++-
 drivers/gpu/drm/Makefile           |   2 +
 drivers/gpu/drm/drm_client_setup.c |  18 +-
 drivers/gpu/drm/drm_draw.c         | 233 ++++++++++++++++
 drivers/gpu/drm/drm_draw.h         |  56 ++++
 drivers/gpu/drm/drm_log.c          | 420 +++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_log.h          |  11 +
 drivers/gpu/drm/drm_panic.c        | 257 ++----------------
 8 files changed, 812 insertions(+), 238 deletions(-)
 create mode 100644 drivers/gpu/drm/drm_draw.c
 create mode 100644 drivers/gpu/drm/drm_draw.h
 create mode 100644 drivers/gpu/drm/drm_log.c
 create mode 100644 drivers/gpu/drm/drm_log.h


base-commit: baf4afc5831438b35de4b0e951b9cd58435a6d99
-- 
2.47.0

[PATCH v7 1/7] drm/panic: Move drawing functions to drm_draw

[Jocelyn Falempe]

Move the color conversions, blit and fill functions to drm_draw.c,
so that they can be re-used by drm_log.
drm_draw is internal to the drm subsystem, and shouldn't be used by
gpu drivers.

Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
---

v5:
 * Export drm_draw symbols, so they can be used if drm_client_lib is built as module.

v6:
 * rebase and solve conflict with "drm/panic: Add ABGR2101010 support"
 
 drivers/gpu/drm/Kconfig     |   5 +
 drivers/gpu/drm/Makefile    |   1 +
 drivers/gpu/drm/drm_draw.c  | 233 ++++++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_draw.h  |  56 ++++++++
 drivers/gpu/drm/drm_panic.c | 257 ++++--------------------------------
 5 files changed, 318 insertions(+), 234 deletions(-)
 create mode 100644 drivers/gpu/drm/drm_draw.c
 create mode 100644 drivers/gpu/drm/drm_draw.h

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 5504721007cc1..3f16dca0b6643 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -102,10 +102,15 @@ config DRM_KMS_HELPER
 	help
 	  CRTC helpers for KMS drivers.
 
+config DRM_DRAW
+	bool
+	depends on DRM
+
 config DRM_PANIC
 	bool "Display a user-friendly message when a kernel panic occurs"
 	depends on DRM
 	select FONT_SUPPORT
+	select DRM_DRAW
 	help
 	  Enable a drm panic handler, which will display a user-friendly message
 	  when a kernel panic occurs. It's useful when using a user-space
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 463afad1b5ca6..68a0a679a7b93 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -91,6 +91,7 @@ drm-$(CONFIG_DRM_PRIVACY_SCREEN) += \
 	drm_privacy_screen_x86.o
 drm-$(CONFIG_DRM_ACCEL) += ../../accel/drm_accel.o
 drm-$(CONFIG_DRM_PANIC) += drm_panic.o
+drm-$(CONFIG_DRM_DRAW) += drm_draw.o
 drm-$(CONFIG_DRM_PANIC_SCREEN_QR_CODE) += drm_panic_qr.o
 obj-$(CONFIG_DRM)	+= drm.o
 
diff --git a/drivers/gpu/drm/drm_draw.c b/drivers/gpu/drm/drm_draw.c
new file mode 100644
index 0000000000000..0fadbf4d9e235
--- /dev/null
+++ b/drivers/gpu/drm/drm_draw.c
@@ -0,0 +1,233 @@
+// SPDX-License-Identifier: GPL-2.0 or MIT
+/*
+ * Copyright (c) 2023 Red Hat.
+ * Author: Jocelyn Falempe <jfalempe@redhat.com>
+ */
+
+#include <linux/bits.h>
+#include <linux/iosys-map.h>
+#include <linux/types.h>
+
+#include <drm/drm_fourcc.h>
+
+#include "drm_draw.h"
+
+/*
+ * Conversions from xrgb8888
+ */
+
+static u16 convert_xrgb8888_to_rgb565(u32 pix)
+{
+	return ((pix & 0x00F80000) >> 8) |
+	       ((pix & 0x0000FC00) >> 5) |
+	       ((pix & 0x000000F8) >> 3);
+}
+
+static u16 convert_xrgb8888_to_rgba5551(u32 pix)
+{
+	return ((pix & 0x00f80000) >> 8) |
+	       ((pix & 0x0000f800) >> 5) |
+	       ((pix & 0x000000f8) >> 2) |
+	       BIT(0); /* set alpha bit */
+}
+
+static u16 convert_xrgb8888_to_xrgb1555(u32 pix)
+{
+	return ((pix & 0x00f80000) >> 9) |
+	       ((pix & 0x0000f800) >> 6) |
+	       ((pix & 0x000000f8) >> 3);
+}
+
+static u16 convert_xrgb8888_to_argb1555(u32 pix)
+{
+	return BIT(15) | /* set alpha bit */
+	       ((pix & 0x00f80000) >> 9) |
+	       ((pix & 0x0000f800) >> 6) |
+	       ((pix & 0x000000f8) >> 3);
+}
+
+static u32 convert_xrgb8888_to_argb8888(u32 pix)
+{
+	return pix | GENMASK(31, 24); /* fill alpha bits */
+}
+
+static u32 convert_xrgb8888_to_xbgr8888(u32 pix)
+{
+	return ((pix & 0x00ff0000) >> 16) <<  0 |
+	       ((pix & 0x0000ff00) >>  8) <<  8 |
+	       ((pix & 0x000000ff) >>  0) << 16 |
+	       ((pix & 0xff000000) >> 24) << 24;
+}
+
+static u32 convert_xrgb8888_to_abgr8888(u32 pix)
+{
+	return ((pix & 0x00ff0000) >> 16) <<  0 |
+	       ((pix & 0x0000ff00) >>  8) <<  8 |
+	       ((pix & 0x000000ff) >>  0) << 16 |
+	       GENMASK(31, 24); /* fill alpha bits */
+}
+
+static u32 convert_xrgb8888_to_xrgb2101010(u32 pix)
+{
+	pix = ((pix & 0x000000FF) << 2) |
+	      ((pix & 0x0000FF00) << 4) |
+	      ((pix & 0x00FF0000) << 6);
+	return pix | ((pix >> 8) & 0x00300C03);
+}
+
+static u32 convert_xrgb8888_to_argb2101010(u32 pix)
+{
+	pix = ((pix & 0x000000FF) << 2) |
+	      ((pix & 0x0000FF00) << 4) |
+	      ((pix & 0x00FF0000) << 6);
+	return GENMASK(31, 30) /* set alpha bits */ | pix | ((pix >> 8) & 0x00300C03);
+}
+
+static u32 convert_xrgb8888_to_abgr2101010(u32 pix)
+{
+	pix = ((pix & 0x00FF0000) >> 14) |
+	      ((pix & 0x0000FF00) << 4) |
+	      ((pix & 0x000000FF) << 22);
+	return GENMASK(31, 30) /* set alpha bits */ | pix | ((pix >> 8) & 0x00300C03);
+}
+
+/**
+ * drm_draw_color_from_xrgb8888 - convert one pixel from xrgb8888 to the desired format
+ * @color: input color, in xrgb8888 format
+ * @format: output format
+ *
+ * Returns:
+ * Color in the format specified, casted to u32.
+ * Or 0 if the format is not supported.
+ */
+u32 drm_draw_color_from_xrgb8888(u32 color, u32 format)
+{
+	switch (format) {
+	case DRM_FORMAT_RGB565:
+		return convert_xrgb8888_to_rgb565(color);
+	case DRM_FORMAT_RGBA5551:
+		return convert_xrgb8888_to_rgba5551(color);
+	case DRM_FORMAT_XRGB1555:
+		return convert_xrgb8888_to_xrgb1555(color);
+	case DRM_FORMAT_ARGB1555:
+		return convert_xrgb8888_to_argb1555(color);
+	case DRM_FORMAT_RGB888:
+	case DRM_FORMAT_XRGB8888:
+		return color;
+	case DRM_FORMAT_ARGB8888:
+		return convert_xrgb8888_to_argb8888(color);
+	case DRM_FORMAT_XBGR8888:
+		return convert_xrgb8888_to_xbgr8888(color);
+	case DRM_FORMAT_ABGR8888:
+		return convert_xrgb8888_to_abgr8888(color);
+	case DRM_FORMAT_XRGB2101010:
+		return convert_xrgb8888_to_xrgb2101010(color);
+	case DRM_FORMAT_ARGB2101010:
+		return convert_xrgb8888_to_argb2101010(color);
+	case DRM_FORMAT_ABGR2101010:
+		return convert_xrgb8888_to_abgr2101010(color);
+	default:
+		WARN_ONCE(1, "Can't convert to %p4cc\n", &format);
+		return 0;
+	}
+}
+EXPORT_SYMBOL(drm_draw_color_from_xrgb8888);
+
+/*
+ * Blit functions
+ */
+void drm_draw_blit16(struct iosys_map *dmap, unsigned int dpitch,
+		     const u8 *sbuf8, unsigned int spitch,
+		     unsigned int height, unsigned int width,
+		     unsigned int scale, u16 fg16)
+{
+	unsigned int y, x;
+
+	for (y = 0; y < height; y++)
+		for (x = 0; x < width; x++)
+			if (drm_draw_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
+				iosys_map_wr(dmap, y * dpitch + x * sizeof(u16), u16, fg16);
+}
+EXPORT_SYMBOL(drm_draw_blit16);
+
+void drm_draw_blit24(struct iosys_map *dmap, unsigned int dpitch,
+		     const u8 *sbuf8, unsigned int spitch,
+		     unsigned int height, unsigned int width,
+		     unsigned int scale, u32 fg32)
+{
+	unsigned int y, x;
+
+	for (y = 0; y < height; y++) {
+		for (x = 0; x < width; x++) {
+			u32 off = y * dpitch + x * 3;
+
+			if (drm_draw_is_pixel_fg(sbuf8, spitch, x / scale, y / scale)) {
+				/* write blue-green-red to output in little endianness */
+				iosys_map_wr(dmap, off, u8, (fg32 & 0x000000FF) >> 0);
+				iosys_map_wr(dmap, off + 1, u8, (fg32 & 0x0000FF00) >> 8);
+				iosys_map_wr(dmap, off + 2, u8, (fg32 & 0x00FF0000) >> 16);
+			}
+		}
+	}
+}
+EXPORT_SYMBOL(drm_draw_blit24);
+
+void drm_draw_blit32(struct iosys_map *dmap, unsigned int dpitch,
+		     const u8 *sbuf8, unsigned int spitch,
+		     unsigned int height, unsigned int width,
+		     unsigned int scale, u32 fg32)
+{
+	unsigned int y, x;
+
+	for (y = 0; y < height; y++)
+		for (x = 0; x < width; x++)
+			if (drm_draw_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
+				iosys_map_wr(dmap, y * dpitch + x * sizeof(u32), u32, fg32);
+}
+EXPORT_SYMBOL(drm_draw_blit32);
+
+/*
+ * Fill functions
+ */
+void drm_draw_fill16(struct iosys_map *dmap, unsigned int dpitch,
+		     unsigned int height, unsigned int width,
+		     u16 color)
+{
+	unsigned int y, x;
+
+	for (y = 0; y < height; y++)
+		for (x = 0; x < width; x++)
+			iosys_map_wr(dmap, y * dpitch + x * sizeof(u16), u16, color);
+}
+EXPORT_SYMBOL(drm_draw_fill16);
+
+void drm_draw_fill24(struct iosys_map *dmap, unsigned int dpitch,
+		     unsigned int height, unsigned int width,
+		     u16 color)
+{
+	unsigned int y, x;
+
+	for (y = 0; y < height; y++) {
+		for (x = 0; x < width; x++) {
+			unsigned int off = y * dpitch + x * 3;
+
+			/* write blue-green-red to output in little endianness */
+			iosys_map_wr(dmap, off, u8, (color & 0x000000FF) >> 0);
+			iosys_map_wr(dmap, off + 1, u8, (color & 0x0000FF00) >> 8);
+			iosys_map_wr(dmap, off + 2, u8, (color & 0x00FF0000) >> 16);
+		}
+	}
+}
+EXPORT_SYMBOL(drm_draw_fill24);
+
+void drm_draw_fill32(struct iosys_map *dmap, unsigned int dpitch,
+		     unsigned int height, unsigned int width,
+		     u32 color)
+{
+	unsigned int y, x;
+
+	for (y = 0; y < height; y++)
+		for (x = 0; x < width; x++)
+			iosys_map_wr(dmap, y * dpitch + x * sizeof(u32), u32, color);
+}
+EXPORT_SYMBOL(drm_draw_fill32);
diff --git a/drivers/gpu/drm/drm_draw.h b/drivers/gpu/drm/drm_draw.h
new file mode 100644
index 0000000000000..b14752e4c4acf
--- /dev/null
+++ b/drivers/gpu/drm/drm_draw.h
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: GPL-2.0 or MIT */
+/*
+ * Copyright (c) 2023 Red Hat.
+ * Author: Jocelyn Falempe <jfalempe@redhat.com>
+ */
+
+#ifndef __DRM_DRAW_H__
+#define __DRM_DRAW_H__
+
+#include <linux/font.h>
+#include <linux/types.h>
+
+struct iosys_map;
+
+/* check if the pixel at coord x,y is 1 (foreground) or 0 (background) */
+static inline bool drm_draw_is_pixel_fg(const u8 *sbuf8, unsigned int spitch, int x, int y)
+{
+	return (sbuf8[(y * spitch) + x / 8] & (0x80 >> (x % 8))) != 0;
+}
+
+static inline const u8 *drm_draw_get_char_bitmap(const struct font_desc *font,
+						 char c, size_t font_pitch)
+{
+	return font->data + (c * font->height) * font_pitch;
+}
+
+u32 drm_draw_color_from_xrgb8888(u32 color, u32 format);
+
+void drm_draw_blit16(struct iosys_map *dmap, unsigned int dpitch,
+		     const u8 *sbuf8, unsigned int spitch,
+		     unsigned int height, unsigned int width,
+		     unsigned int scale, u16 fg16);
+
+void drm_draw_blit24(struct iosys_map *dmap, unsigned int dpitch,
+		     const u8 *sbuf8, unsigned int spitch,
+		     unsigned int height, unsigned int width,
+		     unsigned int scale, u32 fg32);
+
+void drm_draw_blit32(struct iosys_map *dmap, unsigned int dpitch,
+		     const u8 *sbuf8, unsigned int spitch,
+		     unsigned int height, unsigned int width,
+		     unsigned int scale, u32 fg32);
+
+void drm_draw_fill16(struct iosys_map *dmap, unsigned int dpitch,
+		     unsigned int height, unsigned int width,
+		     u16 color);
+
+void drm_draw_fill24(struct iosys_map *dmap, unsigned int dpitch,
+		     unsigned int height, unsigned int width,
+		     u16 color);
+
+void drm_draw_fill32(struct iosys_map *dmap, unsigned int dpitch,
+		     unsigned int height, unsigned int width,
+		     u32 color);
+
+#endif /* __DRM_DRAW_H__ */
diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c
index 0a9ecc1380d2a..27fe83cfc854b 100644
--- a/drivers/gpu/drm/drm_panic.c
+++ b/drivers/gpu/drm/drm_panic.c
@@ -31,6 +31,7 @@
 #include <drm/drm_rect.h>
 
 #include "drm_crtc_internal.h"
+#include "drm_draw.h"
 
 MODULE_AUTHOR("Jocelyn Falempe");
 MODULE_DESCRIPTION("DRM panic handler");
@@ -139,181 +140,8 @@ device_initcall(drm_panic_setup_logo);
 #endif
 
 /*
- * Color conversion
+ *  Blit & Fill functions
  */
-
-static u16 convert_xrgb8888_to_rgb565(u32 pix)
-{
-	return ((pix & 0x00F80000) >> 8) |
-	       ((pix & 0x0000FC00) >> 5) |
-	       ((pix & 0x000000F8) >> 3);
-}
-
-static u16 convert_xrgb8888_to_rgba5551(u32 pix)
-{
-	return ((pix & 0x00f80000) >> 8) |
-	       ((pix & 0x0000f800) >> 5) |
-	       ((pix & 0x000000f8) >> 2) |
-	       BIT(0); /* set alpha bit */
-}
-
-static u16 convert_xrgb8888_to_xrgb1555(u32 pix)
-{
-	return ((pix & 0x00f80000) >> 9) |
-	       ((pix & 0x0000f800) >> 6) |
-	       ((pix & 0x000000f8) >> 3);
-}
-
-static u16 convert_xrgb8888_to_argb1555(u32 pix)
-{
-	return BIT(15) | /* set alpha bit */
-	       ((pix & 0x00f80000) >> 9) |
-	       ((pix & 0x0000f800) >> 6) |
-	       ((pix & 0x000000f8) >> 3);
-}
-
-static u32 convert_xrgb8888_to_argb8888(u32 pix)
-{
-	return pix | GENMASK(31, 24); /* fill alpha bits */
-}
-
-static u32 convert_xrgb8888_to_xbgr8888(u32 pix)
-{
-	return ((pix & 0x00ff0000) >> 16) <<  0 |
-	       ((pix & 0x0000ff00) >>  8) <<  8 |
-	       ((pix & 0x000000ff) >>  0) << 16 |
-	       ((pix & 0xff000000) >> 24) << 24;
-}
-
-static u32 convert_xrgb8888_to_abgr8888(u32 pix)
-{
-	return ((pix & 0x00ff0000) >> 16) <<  0 |
-	       ((pix & 0x0000ff00) >>  8) <<  8 |
-	       ((pix & 0x000000ff) >>  0) << 16 |
-	       GENMASK(31, 24); /* fill alpha bits */
-}
-
-static u32 convert_xrgb8888_to_xrgb2101010(u32 pix)
-{
-	pix = ((pix & 0x000000FF) << 2) |
-	      ((pix & 0x0000FF00) << 4) |
-	      ((pix & 0x00FF0000) << 6);
-	return pix | ((pix >> 8) & 0x00300C03);
-}
-
-static u32 convert_xrgb8888_to_argb2101010(u32 pix)
-{
-	pix = ((pix & 0x000000FF) << 2) |
-	      ((pix & 0x0000FF00) << 4) |
-	      ((pix & 0x00FF0000) << 6);
-	return GENMASK(31, 30) /* set alpha bits */ | pix | ((pix >> 8) & 0x00300C03);
-}
-
-static u32 convert_xrgb8888_to_abgr2101010(u32 pix)
-{
-	pix = ((pix & 0x00FF0000) >> 14) |
-	      ((pix & 0x0000FF00) << 4) |
-	      ((pix & 0x000000FF) << 22);
-	return GENMASK(31, 30) /* set alpha bits */ | pix | ((pix >> 8) & 0x00300C03);
-}
-
-/*
- * convert_from_xrgb8888 - convert one pixel from xrgb8888 to the desired format
- * @color: input color, in xrgb8888 format
- * @format: output format
- *
- * Returns:
- * Color in the format specified, casted to u32.
- * Or 0 if the format is not supported.
- */
-static u32 convert_from_xrgb8888(u32 color, u32 format)
-{
-	switch (format) {
-	case DRM_FORMAT_RGB565:
-		return convert_xrgb8888_to_rgb565(color);
-	case DRM_FORMAT_RGBA5551:
-		return convert_xrgb8888_to_rgba5551(color);
-	case DRM_FORMAT_XRGB1555:
-		return convert_xrgb8888_to_xrgb1555(color);
-	case DRM_FORMAT_ARGB1555:
-		return convert_xrgb8888_to_argb1555(color);
-	case DRM_FORMAT_RGB888:
-	case DRM_FORMAT_XRGB8888:
-		return color;
-	case DRM_FORMAT_ARGB8888:
-		return convert_xrgb8888_to_argb8888(color);
-	case DRM_FORMAT_XBGR8888:
-		return convert_xrgb8888_to_xbgr8888(color);
-	case DRM_FORMAT_ABGR8888:
-		return convert_xrgb8888_to_abgr8888(color);
-	case DRM_FORMAT_XRGB2101010:
-		return convert_xrgb8888_to_xrgb2101010(color);
-	case DRM_FORMAT_ARGB2101010:
-		return convert_xrgb8888_to_argb2101010(color);
-	case DRM_FORMAT_ABGR2101010:
-		return convert_xrgb8888_to_abgr2101010(color);
-	default:
-		WARN_ONCE(1, "Can't convert to %p4cc\n", &format);
-		return 0;
-	}
-}
-
-/*
- * Blit & Fill
- */
-/* check if the pixel at coord x,y is 1 (foreground) or 0 (background) */
-static bool drm_panic_is_pixel_fg(const u8 *sbuf8, unsigned int spitch, int x, int y)
-{
-	return (sbuf8[(y * spitch) + x / 8] & (0x80 >> (x % 8))) != 0;
-}
-
-static void drm_panic_blit16(struct iosys_map *dmap, unsigned int dpitch,
-			     const u8 *sbuf8, unsigned int spitch,
-			     unsigned int height, unsigned int width,
-			     unsigned int scale, u16 fg16)
-{
-	unsigned int y, x;
-
-	for (y = 0; y < height; y++)
-		for (x = 0; x < width; x++)
-			if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
-				iosys_map_wr(dmap, y * dpitch + x * sizeof(u16), u16, fg16);
-}
-
-static void drm_panic_blit24(struct iosys_map *dmap, unsigned int dpitch,
-			     const u8 *sbuf8, unsigned int spitch,
-			     unsigned int height, unsigned int width,
-			     unsigned int scale, u32 fg32)
-{
-	unsigned int y, x;
-
-	for (y = 0; y < height; y++) {
-		for (x = 0; x < width; x++) {
-			u32 off = y * dpitch + x * 3;
-
-			if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale)) {
-				/* write blue-green-red to output in little endianness */
-				iosys_map_wr(dmap, off, u8, (fg32 & 0x000000FF) >> 0);
-				iosys_map_wr(dmap, off + 1, u8, (fg32 & 0x0000FF00) >> 8);
-				iosys_map_wr(dmap, off + 2, u8, (fg32 & 0x00FF0000) >> 16);
-			}
-		}
-	}
-}
-
-static void drm_panic_blit32(struct iosys_map *dmap, unsigned int dpitch,
-			     const u8 *sbuf8, unsigned int spitch,
-			     unsigned int height, unsigned int width,
-			     unsigned int scale, u32 fg32)
-{
-	unsigned int y, x;
-
-	for (y = 0; y < height; y++)
-		for (x = 0; x < width; x++)
-			if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
-				iosys_map_wr(dmap, y * dpitch + x * sizeof(u32), u32, fg32);
-}
-
 static void drm_panic_blit_pixel(struct drm_scanout_buffer *sb, struct drm_rect *clip,
 				 const u8 *sbuf8, unsigned int spitch, unsigned int scale,
 				 u32 fg_color)
@@ -322,7 +150,7 @@ static void drm_panic_blit_pixel(struct drm_scanout_buffer *sb, struct drm_rect
 
 	for (y = 0; y < drm_rect_height(clip); y++)
 		for (x = 0; x < drm_rect_width(clip); x++)
-			if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
+			if (drm_draw_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
 				sb->set_pixel(sb, clip->x1 + x, clip->y1 + y, fg_color);
 }
 
@@ -354,15 +182,15 @@ static void drm_panic_blit(struct drm_scanout_buffer *sb, struct drm_rect *clip,
 
 	switch (sb->format->cpp[0]) {
 	case 2:
-		drm_panic_blit16(&map, sb->pitch[0], sbuf8, spitch,
+		drm_draw_blit16(&map, sb->pitch[0], sbuf8, spitch,
 				 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);
 	break;
 	case 3:
-		drm_panic_blit24(&map, sb->pitch[0], sbuf8, spitch,
+		drm_draw_blit24(&map, sb->pitch[0], sbuf8, spitch,
 				 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);
 	break;
 	case 4:
-		drm_panic_blit32(&map, sb->pitch[0], sbuf8, spitch,
+		drm_draw_blit32(&map, sb->pitch[0], sbuf8, spitch,
 				 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);
 	break;
 	default:
@@ -370,46 +198,6 @@ static void drm_panic_blit(struct drm_scanout_buffer *sb, struct drm_rect *clip,
 	}
 }
 
-static void drm_panic_fill16(struct iosys_map *dmap, unsigned int dpitch,
-			     unsigned int height, unsigned int width,
-			     u16 color)
-{
-	unsigned int y, x;
-
-	for (y = 0; y < height; y++)
-		for (x = 0; x < width; x++)
-			iosys_map_wr(dmap, y * dpitch + x * sizeof(u16), u16, color);
-}
-
-static void drm_panic_fill24(struct iosys_map *dmap, unsigned int dpitch,
-			     unsigned int height, unsigned int width,
-			     u32 color)
-{
-	unsigned int y, x;
-
-	for (y = 0; y < height; y++) {
-		for (x = 0; x < width; x++) {
-			unsigned int off = y * dpitch + x * 3;
-
-			/* write blue-green-red to output in little endianness */
-			iosys_map_wr(dmap, off, u8, (color & 0x000000FF) >> 0);
-			iosys_map_wr(dmap, off + 1, u8, (color & 0x0000FF00) >> 8);
-			iosys_map_wr(dmap, off + 2, u8, (color & 0x00FF0000) >> 16);
-		}
-	}
-}
-
-static void drm_panic_fill32(struct iosys_map *dmap, unsigned int dpitch,
-			     unsigned int height, unsigned int width,
-			     u32 color)
-{
-	unsigned int y, x;
-
-	for (y = 0; y < height; y++)
-		for (x = 0; x < width; x++)
-			iosys_map_wr(dmap, y * dpitch + x * sizeof(u32), u32, color);
-}
-
 static void drm_panic_fill_pixel(struct drm_scanout_buffer *sb,
 				 struct drm_rect *clip,
 				 u32 color)
@@ -442,15 +230,15 @@ static void drm_panic_fill(struct drm_scanout_buffer *sb, struct drm_rect *clip,
 
 	switch (sb->format->cpp[0]) {
 	case 2:
-		drm_panic_fill16(&map, sb->pitch[0], drm_rect_height(clip),
+		drm_draw_fill16(&map, sb->pitch[0], drm_rect_height(clip),
 				 drm_rect_width(clip), color);
 	break;
 	case 3:
-		drm_panic_fill24(&map, sb->pitch[0], drm_rect_height(clip),
+		drm_draw_fill24(&map, sb->pitch[0], drm_rect_height(clip),
 				 drm_rect_width(clip), color);
 	break;
 	case 4:
-		drm_panic_fill32(&map, sb->pitch[0], drm_rect_height(clip),
+		drm_draw_fill32(&map, sb->pitch[0], drm_rect_height(clip),
 				 drm_rect_width(clip), color);
 	break;
 	default:
@@ -458,11 +246,6 @@ static void drm_panic_fill(struct drm_scanout_buffer *sb, struct drm_rect *clip,
 	}
 }
 
-static const u8 *get_char_bitmap(const struct font_desc *font, char c, size_t font_pitch)
-{
-	return font->data + (c * font->height) * font_pitch;
-}
-
 static unsigned int get_max_line_len(const struct drm_panic_line *lines, int len)
 {
 	int i;
@@ -501,7 +284,7 @@ static void draw_txt_rectangle(struct drm_scanout_buffer *sb,
 			rec.x1 += (drm_rect_width(clip) - (line_len * font->width)) / 2;
 
 		for (j = 0; j < line_len; j++) {
-			src = get_char_bitmap(font, msg[i].txt[j], font_pitch);
+			src = drm_draw_get_char_bitmap(font, msg[i].txt[j], font_pitch);
 			rec.x2 = rec.x1 + font->width;
 			drm_panic_blit(sb, &rec, src, font_pitch, 1, color);
 			rec.x1 += font->width;
@@ -533,8 +316,10 @@ static void drm_panic_logo_draw(struct drm_scanout_buffer *sb, struct drm_rect *
 
 static void draw_panic_static_user(struct drm_scanout_buffer *sb)
 {
-	u32 fg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, sb->format->format);
-	u32 bg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, sb->format->format);
+	u32 fg_color = drm_draw_color_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR,
+						    sb->format->format);
+	u32 bg_color = drm_draw_color_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR,
+						    sb->format->format);
 	const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL);
 	struct drm_rect r_screen, r_logo, r_msg;
 	unsigned int msg_width, msg_height;
@@ -600,8 +385,10 @@ static int draw_line_with_wrap(struct drm_scanout_buffer *sb, const struct font_
  */
 static void draw_panic_static_kmsg(struct drm_scanout_buffer *sb)
 {
-	u32 fg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, sb->format->format);
-	u32 bg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, sb->format->format);
+	u32 fg_color = drm_draw_color_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR,
+						    sb->format->format);
+	u32 bg_color = drm_draw_color_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR,
+						    sb->format->format);
 	const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL);
 	struct drm_rect r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height);
 	struct kmsg_dump_iter iter;
@@ -791,8 +578,10 @@ static int drm_panic_get_qr_code(u8 **qr_image)
  */
 static int _draw_panic_static_qr_code(struct drm_scanout_buffer *sb)
 {
-	u32 fg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, sb->format->format);
-	u32 bg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, sb->format->format);
+	u32 fg_color = drm_draw_color_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR,
+						    sb->format->format);
+	u32 bg_color = drm_draw_color_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR,
+						    sb->format->format);
 	const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL);
 	struct drm_rect r_screen, r_logo, r_msg, r_qr, r_qr_canvas;
 	unsigned int max_qr_size, scale;
@@ -878,7 +667,7 @@ static bool drm_panic_is_format_supported(const struct drm_format_info *format)
 {
 	if (format->num_planes != 1)
 		return false;
-	return convert_from_xrgb8888(0xffffff, format->format) != 0;
+	return drm_draw_color_from_xrgb8888(0xffffff, format->format) != 0;
 }
 
 static void draw_panic_dispatch(struct drm_scanout_buffer *sb)
-- 
2.47.0

Re: [PATCH v7 1/7] drm/panic: Move drawing functions to drm_draw

[Thomas Zimmermann]

Hi


Am 08.11.24 um 09:10 schrieb Jocelyn Falempe:
> Move the color conversions, blit and fill functions to drm_draw.c,
> so that they can be re-used by drm_log.
> drm_draw is internal to the drm subsystem, and shouldn't be used by
> gpu drivers.

Just a remark on this patch: I don't like the proliferation of drawing 
APIs. We have this one, we have the format helpers, the vkms code. And 
there's drawing code in fbdev as well. At some point, we will require a 
solution to this problem.

Best regards
Thomas

>
> Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
> ---
>
> v5:
>   * Export drm_draw symbols, so they can be used if drm_client_lib is built as module.
>
> v6:
>   * rebase and solve conflict with "drm/panic: Add ABGR2101010 support"
>   
>   drivers/gpu/drm/Kconfig     |   5 +
>   drivers/gpu/drm/Makefile    |   1 +
>   drivers/gpu/drm/drm_draw.c  | 233 ++++++++++++++++++++++++++++++++
>   drivers/gpu/drm/drm_draw.h  |  56 ++++++++
>   drivers/gpu/drm/drm_panic.c | 257 ++++--------------------------------
>   5 files changed, 318 insertions(+), 234 deletions(-)
>   create mode 100644 drivers/gpu/drm/drm_draw.c
>   create mode 100644 drivers/gpu/drm/drm_draw.h
>
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index 5504721007cc1..3f16dca0b6643 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -102,10 +102,15 @@ config DRM_KMS_HELPER
>   	help
>   	  CRTC helpers for KMS drivers.
>   
> +config DRM_DRAW
> +	bool
> +	depends on DRM
> +
>   config DRM_PANIC
>   	bool "Display a user-friendly message when a kernel panic occurs"
>   	depends on DRM
>   	select FONT_SUPPORT
> +	select DRM_DRAW
>   	help
>   	  Enable a drm panic handler, which will display a user-friendly message
>   	  when a kernel panic occurs. It's useful when using a user-space
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 463afad1b5ca6..68a0a679a7b93 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -91,6 +91,7 @@ drm-$(CONFIG_DRM_PRIVACY_SCREEN) += \
>   	drm_privacy_screen_x86.o
>   drm-$(CONFIG_DRM_ACCEL) += ../../accel/drm_accel.o
>   drm-$(CONFIG_DRM_PANIC) += drm_panic.o
> +drm-$(CONFIG_DRM_DRAW) += drm_draw.o
>   drm-$(CONFIG_DRM_PANIC_SCREEN_QR_CODE) += drm_panic_qr.o
>   obj-$(CONFIG_DRM)	+= drm.o
>   
> diff --git a/drivers/gpu/drm/drm_draw.c b/drivers/gpu/drm/drm_draw.c
> new file mode 100644
> index 0000000000000..0fadbf4d9e235
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_draw.c
> @@ -0,0 +1,233 @@
> +// SPDX-License-Identifier: GPL-2.0 or MIT
> +/*
> + * Copyright (c) 2023 Red Hat.
> + * Author: Jocelyn Falempe <jfalempe@redhat.com>
> + */
> +
> +#include <linux/bits.h>
> +#include <linux/iosys-map.h>
> +#include <linux/types.h>
> +
> +#include <drm/drm_fourcc.h>
> +
> +#include "drm_draw.h"
> +
> +/*
> + * Conversions from xrgb8888
> + */
> +
> +static u16 convert_xrgb8888_to_rgb565(u32 pix)
> +{
> +	return ((pix & 0x00F80000) >> 8) |
> +	       ((pix & 0x0000FC00) >> 5) |
> +	       ((pix & 0x000000F8) >> 3);
> +}
> +
> +static u16 convert_xrgb8888_to_rgba5551(u32 pix)
> +{
> +	return ((pix & 0x00f80000) >> 8) |
> +	       ((pix & 0x0000f800) >> 5) |
> +	       ((pix & 0x000000f8) >> 2) |
> +	       BIT(0); /* set alpha bit */
> +}
> +
> +static u16 convert_xrgb8888_to_xrgb1555(u32 pix)
> +{
> +	return ((pix & 0x00f80000) >> 9) |
> +	       ((pix & 0x0000f800) >> 6) |
> +	       ((pix & 0x000000f8) >> 3);
> +}
> +
> +static u16 convert_xrgb8888_to_argb1555(u32 pix)
> +{
> +	return BIT(15) | /* set alpha bit */
> +	       ((pix & 0x00f80000) >> 9) |
> +	       ((pix & 0x0000f800) >> 6) |
> +	       ((pix & 0x000000f8) >> 3);
> +}
> +
> +static u32 convert_xrgb8888_to_argb8888(u32 pix)
> +{
> +	return pix | GENMASK(31, 24); /* fill alpha bits */
> +}
> +
> +static u32 convert_xrgb8888_to_xbgr8888(u32 pix)
> +{
> +	return ((pix & 0x00ff0000) >> 16) <<  0 |
> +	       ((pix & 0x0000ff00) >>  8) <<  8 |
> +	       ((pix & 0x000000ff) >>  0) << 16 |
> +	       ((pix & 0xff000000) >> 24) << 24;
> +}
> +
> +static u32 convert_xrgb8888_to_abgr8888(u32 pix)
> +{
> +	return ((pix & 0x00ff0000) >> 16) <<  0 |
> +	       ((pix & 0x0000ff00) >>  8) <<  8 |
> +	       ((pix & 0x000000ff) >>  0) << 16 |
> +	       GENMASK(31, 24); /* fill alpha bits */
> +}
> +
> +static u32 convert_xrgb8888_to_xrgb2101010(u32 pix)
> +{
> +	pix = ((pix & 0x000000FF) << 2) |
> +	      ((pix & 0x0000FF00) << 4) |
> +	      ((pix & 0x00FF0000) << 6);
> +	return pix | ((pix >> 8) & 0x00300C03);
> +}
> +
> +static u32 convert_xrgb8888_to_argb2101010(u32 pix)
> +{
> +	pix = ((pix & 0x000000FF) << 2) |
> +	      ((pix & 0x0000FF00) << 4) |
> +	      ((pix & 0x00FF0000) << 6);
> +	return GENMASK(31, 30) /* set alpha bits */ | pix | ((pix >> 8) & 0x00300C03);
> +}
> +
> +static u32 convert_xrgb8888_to_abgr2101010(u32 pix)
> +{
> +	pix = ((pix & 0x00FF0000) >> 14) |
> +	      ((pix & 0x0000FF00) << 4) |
> +	      ((pix & 0x000000FF) << 22);
> +	return GENMASK(31, 30) /* set alpha bits */ | pix | ((pix >> 8) & 0x00300C03);
> +}
> +
> +/**
> + * drm_draw_color_from_xrgb8888 - convert one pixel from xrgb8888 to the desired format
> + * @color: input color, in xrgb8888 format
> + * @format: output format
> + *
> + * Returns:
> + * Color in the format specified, casted to u32.
> + * Or 0 if the format is not supported.
> + */
> +u32 drm_draw_color_from_xrgb8888(u32 color, u32 format)
> +{
> +	switch (format) {
> +	case DRM_FORMAT_RGB565:
> +		return convert_xrgb8888_to_rgb565(color);
> +	case DRM_FORMAT_RGBA5551:
> +		return convert_xrgb8888_to_rgba5551(color);
> +	case DRM_FORMAT_XRGB1555:
> +		return convert_xrgb8888_to_xrgb1555(color);
> +	case DRM_FORMAT_ARGB1555:
> +		return convert_xrgb8888_to_argb1555(color);
> +	case DRM_FORMAT_RGB888:
> +	case DRM_FORMAT_XRGB8888:
> +		return color;
> +	case DRM_FORMAT_ARGB8888:
> +		return convert_xrgb8888_to_argb8888(color);
> +	case DRM_FORMAT_XBGR8888:
> +		return convert_xrgb8888_to_xbgr8888(color);
> +	case DRM_FORMAT_ABGR8888:
> +		return convert_xrgb8888_to_abgr8888(color);
> +	case DRM_FORMAT_XRGB2101010:
> +		return convert_xrgb8888_to_xrgb2101010(color);
> +	case DRM_FORMAT_ARGB2101010:
> +		return convert_xrgb8888_to_argb2101010(color);
> +	case DRM_FORMAT_ABGR2101010:
> +		return convert_xrgb8888_to_abgr2101010(color);
> +	default:
> +		WARN_ONCE(1, "Can't convert to %p4cc\n", &format);
> +		return 0;
> +	}
> +}
> +EXPORT_SYMBOL(drm_draw_color_from_xrgb8888);
> +
> +/*
> + * Blit functions
> + */
> +void drm_draw_blit16(struct iosys_map *dmap, unsigned int dpitch,
> +		     const u8 *sbuf8, unsigned int spitch,
> +		     unsigned int height, unsigned int width,
> +		     unsigned int scale, u16 fg16)
> +{
> +	unsigned int y, x;
> +
> +	for (y = 0; y < height; y++)
> +		for (x = 0; x < width; x++)
> +			if (drm_draw_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
> +				iosys_map_wr(dmap, y * dpitch + x * sizeof(u16), u16, fg16);
> +}
> +EXPORT_SYMBOL(drm_draw_blit16);
> +
> +void drm_draw_blit24(struct iosys_map *dmap, unsigned int dpitch,
> +		     const u8 *sbuf8, unsigned int spitch,
> +		     unsigned int height, unsigned int width,
> +		     unsigned int scale, u32 fg32)
> +{
> +	unsigned int y, x;
> +
> +	for (y = 0; y < height; y++) {
> +		for (x = 0; x < width; x++) {
> +			u32 off = y * dpitch + x * 3;
> +
> +			if (drm_draw_is_pixel_fg(sbuf8, spitch, x / scale, y / scale)) {
> +				/* write blue-green-red to output in little endianness */
> +				iosys_map_wr(dmap, off, u8, (fg32 & 0x000000FF) >> 0);
> +				iosys_map_wr(dmap, off + 1, u8, (fg32 & 0x0000FF00) >> 8);
> +				iosys_map_wr(dmap, off + 2, u8, (fg32 & 0x00FF0000) >> 16);
> +			}
> +		}
> +	}
> +}
> +EXPORT_SYMBOL(drm_draw_blit24);
> +
> +void drm_draw_blit32(struct iosys_map *dmap, unsigned int dpitch,
> +		     const u8 *sbuf8, unsigned int spitch,
> +		     unsigned int height, unsigned int width,
> +		     unsigned int scale, u32 fg32)
> +{
> +	unsigned int y, x;
> +
> +	for (y = 0; y < height; y++)
> +		for (x = 0; x < width; x++)
> +			if (drm_draw_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
> +				iosys_map_wr(dmap, y * dpitch + x * sizeof(u32), u32, fg32);
> +}
> +EXPORT_SYMBOL(drm_draw_blit32);
> +
> +/*
> + * Fill functions
> + */
> +void drm_draw_fill16(struct iosys_map *dmap, unsigned int dpitch,
> +		     unsigned int height, unsigned int width,
> +		     u16 color)
> +{
> +	unsigned int y, x;
> +
> +	for (y = 0; y < height; y++)
> +		for (x = 0; x < width; x++)
> +			iosys_map_wr(dmap, y * dpitch + x * sizeof(u16), u16, color);
> +}
> +EXPORT_SYMBOL(drm_draw_fill16);
> +
> +void drm_draw_fill24(struct iosys_map *dmap, unsigned int dpitch,
> +		     unsigned int height, unsigned int width,
> +		     u16 color)
> +{
> +	unsigned int y, x;
> +
> +	for (y = 0; y < height; y++) {
> +		for (x = 0; x < width; x++) {
> +			unsigned int off = y * dpitch + x * 3;
> +
> +			/* write blue-green-red to output in little endianness */
> +			iosys_map_wr(dmap, off, u8, (color & 0x000000FF) >> 0);
> +			iosys_map_wr(dmap, off + 1, u8, (color & 0x0000FF00) >> 8);
> +			iosys_map_wr(dmap, off + 2, u8, (color & 0x00FF0000) >> 16);
> +		}
> +	}
> +}
> +EXPORT_SYMBOL(drm_draw_fill24);
> +
> +void drm_draw_fill32(struct iosys_map *dmap, unsigned int dpitch,
> +		     unsigned int height, unsigned int width,
> +		     u32 color)
> +{
> +	unsigned int y, x;
> +
> +	for (y = 0; y < height; y++)
> +		for (x = 0; x < width; x++)
> +			iosys_map_wr(dmap, y * dpitch + x * sizeof(u32), u32, color);
> +}
> +EXPORT_SYMBOL(drm_draw_fill32);
> diff --git a/drivers/gpu/drm/drm_draw.h b/drivers/gpu/drm/drm_draw.h
> new file mode 100644
> index 0000000000000..b14752e4c4acf
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_draw.h
> @@ -0,0 +1,56 @@
> +/* SPDX-License-Identifier: GPL-2.0 or MIT */
> +/*
> + * Copyright (c) 2023 Red Hat.
> + * Author: Jocelyn Falempe <jfalempe@redhat.com>
> + */
> +
> +#ifndef __DRM_DRAW_H__
> +#define __DRM_DRAW_H__
> +
> +#include <linux/font.h>
> +#include <linux/types.h>
> +
> +struct iosys_map;
> +
> +/* check if the pixel at coord x,y is 1 (foreground) or 0 (background) */
> +static inline bool drm_draw_is_pixel_fg(const u8 *sbuf8, unsigned int spitch, int x, int y)
> +{
> +	return (sbuf8[(y * spitch) + x / 8] & (0x80 >> (x % 8))) != 0;
> +}
> +
> +static inline const u8 *drm_draw_get_char_bitmap(const struct font_desc *font,
> +						 char c, size_t font_pitch)
> +{
> +	return font->data + (c * font->height) * font_pitch;
> +}
> +
> +u32 drm_draw_color_from_xrgb8888(u32 color, u32 format);
> +
> +void drm_draw_blit16(struct iosys_map *dmap, unsigned int dpitch,
> +		     const u8 *sbuf8, unsigned int spitch,
> +		     unsigned int height, unsigned int width,
> +		     unsigned int scale, u16 fg16);
> +
> +void drm_draw_blit24(struct iosys_map *dmap, unsigned int dpitch,
> +		     const u8 *sbuf8, unsigned int spitch,
> +		     unsigned int height, unsigned int width,
> +		     unsigned int scale, u32 fg32);
> +
> +void drm_draw_blit32(struct iosys_map *dmap, unsigned int dpitch,
> +		     const u8 *sbuf8, unsigned int spitch,
> +		     unsigned int height, unsigned int width,
> +		     unsigned int scale, u32 fg32);
> +
> +void drm_draw_fill16(struct iosys_map *dmap, unsigned int dpitch,
> +		     unsigned int height, unsigned int width,
> +		     u16 color);
> +
> +void drm_draw_fill24(struct iosys_map *dmap, unsigned int dpitch,
> +		     unsigned int height, unsigned int width,
> +		     u16 color);
> +
> +void drm_draw_fill32(struct iosys_map *dmap, unsigned int dpitch,
> +		     unsigned int height, unsigned int width,
> +		     u32 color);
> +
> +#endif /* __DRM_DRAW_H__ */
> diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c
> index 0a9ecc1380d2a..27fe83cfc854b 100644
> --- a/drivers/gpu/drm/drm_panic.c
> +++ b/drivers/gpu/drm/drm_panic.c
> @@ -31,6 +31,7 @@
>   #include <drm/drm_rect.h>
>   
>   #include "drm_crtc_internal.h"
> +#include "drm_draw.h"
>   
>   MODULE_AUTHOR("Jocelyn Falempe");
>   MODULE_DESCRIPTION("DRM panic handler");
> @@ -139,181 +140,8 @@ device_initcall(drm_panic_setup_logo);
>   #endif
>   
>   /*
> - * Color conversion
> + *  Blit & Fill functions
>    */
> -
> -static u16 convert_xrgb8888_to_rgb565(u32 pix)
> -{
> -	return ((pix & 0x00F80000) >> 8) |
> -	       ((pix & 0x0000FC00) >> 5) |
> -	       ((pix & 0x000000F8) >> 3);
> -}
> -
> -static u16 convert_xrgb8888_to_rgba5551(u32 pix)
> -{
> -	return ((pix & 0x00f80000) >> 8) |
> -	       ((pix & 0x0000f800) >> 5) |
> -	       ((pix & 0x000000f8) >> 2) |
> -	       BIT(0); /* set alpha bit */
> -}
> -
> -static u16 convert_xrgb8888_to_xrgb1555(u32 pix)
> -{
> -	return ((pix & 0x00f80000) >> 9) |
> -	       ((pix & 0x0000f800) >> 6) |
> -	       ((pix & 0x000000f8) >> 3);
> -}
> -
> -static u16 convert_xrgb8888_to_argb1555(u32 pix)
> -{
> -	return BIT(15) | /* set alpha bit */
> -	       ((pix & 0x00f80000) >> 9) |
> -	       ((pix & 0x0000f800) >> 6) |
> -	       ((pix & 0x000000f8) >> 3);
> -}
> -
> -static u32 convert_xrgb8888_to_argb8888(u32 pix)
> -{
> -	return pix | GENMASK(31, 24); /* fill alpha bits */
> -}
> -
> -static u32 convert_xrgb8888_to_xbgr8888(u32 pix)
> -{
> -	return ((pix & 0x00ff0000) >> 16) <<  0 |
> -	       ((pix & 0x0000ff00) >>  8) <<  8 |
> -	       ((pix & 0x000000ff) >>  0) << 16 |
> -	       ((pix & 0xff000000) >> 24) << 24;
> -}
> -
> -static u32 convert_xrgb8888_to_abgr8888(u32 pix)
> -{
> -	return ((pix & 0x00ff0000) >> 16) <<  0 |
> -	       ((pix & 0x0000ff00) >>  8) <<  8 |
> -	       ((pix & 0x000000ff) >>  0) << 16 |
> -	       GENMASK(31, 24); /* fill alpha bits */
> -}
> -
> -static u32 convert_xrgb8888_to_xrgb2101010(u32 pix)
> -{
> -	pix = ((pix & 0x000000FF) << 2) |
> -	      ((pix & 0x0000FF00) << 4) |
> -	      ((pix & 0x00FF0000) << 6);
> -	return pix | ((pix >> 8) & 0x00300C03);
> -}
> -
> -static u32 convert_xrgb8888_to_argb2101010(u32 pix)
> -{
> -	pix = ((pix & 0x000000FF) << 2) |
> -	      ((pix & 0x0000FF00) << 4) |
> -	      ((pix & 0x00FF0000) << 6);
> -	return GENMASK(31, 30) /* set alpha bits */ | pix | ((pix >> 8) & 0x00300C03);
> -}
> -
> -static u32 convert_xrgb8888_to_abgr2101010(u32 pix)
> -{
> -	pix = ((pix & 0x00FF0000) >> 14) |
> -	      ((pix & 0x0000FF00) << 4) |
> -	      ((pix & 0x000000FF) << 22);
> -	return GENMASK(31, 30) /* set alpha bits */ | pix | ((pix >> 8) & 0x00300C03);
> -}
> -
> -/*
> - * convert_from_xrgb8888 - convert one pixel from xrgb8888 to the desired format
> - * @color: input color, in xrgb8888 format
> - * @format: output format
> - *
> - * Returns:
> - * Color in the format specified, casted to u32.
> - * Or 0 if the format is not supported.
> - */
> -static u32 convert_from_xrgb8888(u32 color, u32 format)
> -{
> -	switch (format) {
> -	case DRM_FORMAT_RGB565:
> -		return convert_xrgb8888_to_rgb565(color);
> -	case DRM_FORMAT_RGBA5551:
> -		return convert_xrgb8888_to_rgba5551(color);
> -	case DRM_FORMAT_XRGB1555:
> -		return convert_xrgb8888_to_xrgb1555(color);
> -	case DRM_FORMAT_ARGB1555:
> -		return convert_xrgb8888_to_argb1555(color);
> -	case DRM_FORMAT_RGB888:
> -	case DRM_FORMAT_XRGB8888:
> -		return color;
> -	case DRM_FORMAT_ARGB8888:
> -		return convert_xrgb8888_to_argb8888(color);
> -	case DRM_FORMAT_XBGR8888:
> -		return convert_xrgb8888_to_xbgr8888(color);
> -	case DRM_FORMAT_ABGR8888:
> -		return convert_xrgb8888_to_abgr8888(color);
> -	case DRM_FORMAT_XRGB2101010:
> -		return convert_xrgb8888_to_xrgb2101010(color);
> -	case DRM_FORMAT_ARGB2101010:
> -		return convert_xrgb8888_to_argb2101010(color);
> -	case DRM_FORMAT_ABGR2101010:
> -		return convert_xrgb8888_to_abgr2101010(color);
> -	default:
> -		WARN_ONCE(1, "Can't convert to %p4cc\n", &format);
> -		return 0;
> -	}
> -}
> -
> -/*
> - * Blit & Fill
> - */
> -/* check if the pixel at coord x,y is 1 (foreground) or 0 (background) */
> -static bool drm_panic_is_pixel_fg(const u8 *sbuf8, unsigned int spitch, int x, int y)
> -{
> -	return (sbuf8[(y * spitch) + x / 8] & (0x80 >> (x % 8))) != 0;
> -}
> -
> -static void drm_panic_blit16(struct iosys_map *dmap, unsigned int dpitch,
> -			     const u8 *sbuf8, unsigned int spitch,
> -			     unsigned int height, unsigned int width,
> -			     unsigned int scale, u16 fg16)
> -{
> -	unsigned int y, x;
> -
> -	for (y = 0; y < height; y++)
> -		for (x = 0; x < width; x++)
> -			if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
> -				iosys_map_wr(dmap, y * dpitch + x * sizeof(u16), u16, fg16);
> -}
> -
> -static void drm_panic_blit24(struct iosys_map *dmap, unsigned int dpitch,
> -			     const u8 *sbuf8, unsigned int spitch,
> -			     unsigned int height, unsigned int width,
> -			     unsigned int scale, u32 fg32)
> -{
> -	unsigned int y, x;
> -
> -	for (y = 0; y < height; y++) {
> -		for (x = 0; x < width; x++) {
> -			u32 off = y * dpitch + x * 3;
> -
> -			if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale)) {
> -				/* write blue-green-red to output in little endianness */
> -				iosys_map_wr(dmap, off, u8, (fg32 & 0x000000FF) >> 0);
> -				iosys_map_wr(dmap, off + 1, u8, (fg32 & 0x0000FF00) >> 8);
> -				iosys_map_wr(dmap, off + 2, u8, (fg32 & 0x00FF0000) >> 16);
> -			}
> -		}
> -	}
> -}
> -
> -static void drm_panic_blit32(struct iosys_map *dmap, unsigned int dpitch,
> -			     const u8 *sbuf8, unsigned int spitch,
> -			     unsigned int height, unsigned int width,
> -			     unsigned int scale, u32 fg32)
> -{
> -	unsigned int y, x;
> -
> -	for (y = 0; y < height; y++)
> -		for (x = 0; x < width; x++)
> -			if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
> -				iosys_map_wr(dmap, y * dpitch + x * sizeof(u32), u32, fg32);
> -}
> -
>   static void drm_panic_blit_pixel(struct drm_scanout_buffer *sb, struct drm_rect *clip,
>   				 const u8 *sbuf8, unsigned int spitch, unsigned int scale,
>   				 u32 fg_color)
> @@ -322,7 +150,7 @@ static void drm_panic_blit_pixel(struct drm_scanout_buffer *sb, struct drm_rect
>   
>   	for (y = 0; y < drm_rect_height(clip); y++)
>   		for (x = 0; x < drm_rect_width(clip); x++)
> -			if (drm_panic_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
> +			if (drm_draw_is_pixel_fg(sbuf8, spitch, x / scale, y / scale))
>   				sb->set_pixel(sb, clip->x1 + x, clip->y1 + y, fg_color);
>   }
>   
> @@ -354,15 +182,15 @@ static void drm_panic_blit(struct drm_scanout_buffer *sb, struct drm_rect *clip,
>   
>   	switch (sb->format->cpp[0]) {
>   	case 2:
> -		drm_panic_blit16(&map, sb->pitch[0], sbuf8, spitch,
> +		drm_draw_blit16(&map, sb->pitch[0], sbuf8, spitch,
>   				 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);
>   	break;
>   	case 3:
> -		drm_panic_blit24(&map, sb->pitch[0], sbuf8, spitch,
> +		drm_draw_blit24(&map, sb->pitch[0], sbuf8, spitch,
>   				 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);
>   	break;
>   	case 4:
> -		drm_panic_blit32(&map, sb->pitch[0], sbuf8, spitch,
> +		drm_draw_blit32(&map, sb->pitch[0], sbuf8, spitch,
>   				 drm_rect_height(clip), drm_rect_width(clip), scale, fg_color);
>   	break;
>   	default:
> @@ -370,46 +198,6 @@ static void drm_panic_blit(struct drm_scanout_buffer *sb, struct drm_rect *clip,
>   	}
>   }
>   
> -static void drm_panic_fill16(struct iosys_map *dmap, unsigned int dpitch,
> -			     unsigned int height, unsigned int width,
> -			     u16 color)
> -{
> -	unsigned int y, x;
> -
> -	for (y = 0; y < height; y++)
> -		for (x = 0; x < width; x++)
> -			iosys_map_wr(dmap, y * dpitch + x * sizeof(u16), u16, color);
> -}
> -
> -static void drm_panic_fill24(struct iosys_map *dmap, unsigned int dpitch,
> -			     unsigned int height, unsigned int width,
> -			     u32 color)
> -{
> -	unsigned int y, x;
> -
> -	for (y = 0; y < height; y++) {
> -		for (x = 0; x < width; x++) {
> -			unsigned int off = y * dpitch + x * 3;
> -
> -			/* write blue-green-red to output in little endianness */
> -			iosys_map_wr(dmap, off, u8, (color & 0x000000FF) >> 0);
> -			iosys_map_wr(dmap, off + 1, u8, (color & 0x0000FF00) >> 8);
> -			iosys_map_wr(dmap, off + 2, u8, (color & 0x00FF0000) >> 16);
> -		}
> -	}
> -}
> -
> -static void drm_panic_fill32(struct iosys_map *dmap, unsigned int dpitch,
> -			     unsigned int height, unsigned int width,
> -			     u32 color)
> -{
> -	unsigned int y, x;
> -
> -	for (y = 0; y < height; y++)
> -		for (x = 0; x < width; x++)
> -			iosys_map_wr(dmap, y * dpitch + x * sizeof(u32), u32, color);
> -}
> -
>   static void drm_panic_fill_pixel(struct drm_scanout_buffer *sb,
>   				 struct drm_rect *clip,
>   				 u32 color)
> @@ -442,15 +230,15 @@ static void drm_panic_fill(struct drm_scanout_buffer *sb, struct drm_rect *clip,
>   
>   	switch (sb->format->cpp[0]) {
>   	case 2:
> -		drm_panic_fill16(&map, sb->pitch[0], drm_rect_height(clip),
> +		drm_draw_fill16(&map, sb->pitch[0], drm_rect_height(clip),
>   				 drm_rect_width(clip), color);
>   	break;
>   	case 3:
> -		drm_panic_fill24(&map, sb->pitch[0], drm_rect_height(clip),
> +		drm_draw_fill24(&map, sb->pitch[0], drm_rect_height(clip),
>   				 drm_rect_width(clip), color);
>   	break;
>   	case 4:
> -		drm_panic_fill32(&map, sb->pitch[0], drm_rect_height(clip),
> +		drm_draw_fill32(&map, sb->pitch[0], drm_rect_height(clip),
>   				 drm_rect_width(clip), color);
>   	break;
>   	default:
> @@ -458,11 +246,6 @@ static void drm_panic_fill(struct drm_scanout_buffer *sb, struct drm_rect *clip,
>   	}
>   }
>   
> -static const u8 *get_char_bitmap(const struct font_desc *font, char c, size_t font_pitch)
> -{
> -	return font->data + (c * font->height) * font_pitch;
> -}
> -
>   static unsigned int get_max_line_len(const struct drm_panic_line *lines, int len)
>   {
>   	int i;
> @@ -501,7 +284,7 @@ static void draw_txt_rectangle(struct drm_scanout_buffer *sb,
>   			rec.x1 += (drm_rect_width(clip) - (line_len * font->width)) / 2;
>   
>   		for (j = 0; j < line_len; j++) {
> -			src = get_char_bitmap(font, msg[i].txt[j], font_pitch);
> +			src = drm_draw_get_char_bitmap(font, msg[i].txt[j], font_pitch);
>   			rec.x2 = rec.x1 + font->width;
>   			drm_panic_blit(sb, &rec, src, font_pitch, 1, color);
>   			rec.x1 += font->width;
> @@ -533,8 +316,10 @@ static void drm_panic_logo_draw(struct drm_scanout_buffer *sb, struct drm_rect *
>   
>   static void draw_panic_static_user(struct drm_scanout_buffer *sb)
>   {
> -	u32 fg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, sb->format->format);
> -	u32 bg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, sb->format->format);
> +	u32 fg_color = drm_draw_color_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR,
> +						    sb->format->format);
> +	u32 bg_color = drm_draw_color_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR,
> +						    sb->format->format);
>   	const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL);
>   	struct drm_rect r_screen, r_logo, r_msg;
>   	unsigned int msg_width, msg_height;
> @@ -600,8 +385,10 @@ static int draw_line_with_wrap(struct drm_scanout_buffer *sb, const struct font_
>    */
>   static void draw_panic_static_kmsg(struct drm_scanout_buffer *sb)
>   {
> -	u32 fg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, sb->format->format);
> -	u32 bg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, sb->format->format);
> +	u32 fg_color = drm_draw_color_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR,
> +						    sb->format->format);
> +	u32 bg_color = drm_draw_color_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR,
> +						    sb->format->format);
>   	const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL);
>   	struct drm_rect r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height);
>   	struct kmsg_dump_iter iter;
> @@ -791,8 +578,10 @@ static int drm_panic_get_qr_code(u8 **qr_image)
>    */
>   static int _draw_panic_static_qr_code(struct drm_scanout_buffer *sb)
>   {
> -	u32 fg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR, sb->format->format);
> -	u32 bg_color = convert_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR, sb->format->format);
> +	u32 fg_color = drm_draw_color_from_xrgb8888(CONFIG_DRM_PANIC_FOREGROUND_COLOR,
> +						    sb->format->format);
> +	u32 bg_color = drm_draw_color_from_xrgb8888(CONFIG_DRM_PANIC_BACKGROUND_COLOR,
> +						    sb->format->format);
>   	const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL);
>   	struct drm_rect r_screen, r_logo, r_msg, r_qr, r_qr_canvas;
>   	unsigned int max_qr_size, scale;
> @@ -878,7 +667,7 @@ static bool drm_panic_is_format_supported(const struct drm_format_info *format)
>   {
>   	if (format->num_planes != 1)
>   		return false;
> -	return convert_from_xrgb8888(0xffffff, format->format) != 0;
> +	return drm_draw_color_from_xrgb8888(0xffffff, format->format) != 0;
>   }
>   
>   static void draw_panic_dispatch(struct drm_scanout_buffer *sb)

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)

[PATCH v7 2/7] drm/client: Always select DRM_CLIENT_LIB

[Jocelyn Falempe]

DRM_CLIENT_LIB has the code to select the client at runtime, so it should be
always selected by DRM_CLIENT_SELECTION.

Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
---

v7:
 * Added in v7, to fix a build issue, if DRM_LOG is enabled but DRM_CLIENT_LIB is not.
 
 drivers/gpu/drm/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 3f16dca0b6643..eabedfc11061c 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -234,7 +234,7 @@ config DRM_CLIENT_LIB
 config DRM_CLIENT_SELECTION
 	tristate
 	depends on DRM
-	select DRM_CLIENT_LIB if DRM_FBDEV_EMULATION
+	select DRM_CLIENT_LIB
 	help
 	  Drivers that support in-kernel DRM clients have to select this
 	  option.
-- 
2.47.0

Re: [PATCH v7 2/7] drm/client: Always select DRM_CLIENT_LIB

[kernel test robot]

Hi Jocelyn,

kernel test robot noticed the following build errors:

[auto build test ERROR on baf4afc5831438b35de4b0e951b9cd58435a6d99]

url:    https://github.com/intel-lab-lkp/linux/commits/Jocelyn-Falempe/drm-panic-Move-drawing-functions-to-drm_draw/20241108-162222
base:   baf4afc5831438b35de4b0e951b9cd58435a6d99
patch link:    https://lore.kernel.org/r/20241108082025.1004653-3-jfalempe%40redhat.com
patch subject: [PATCH v7 2/7] drm/client: Always select DRM_CLIENT_LIB
config: x86_64-defconfig (https://download.01.org/0day-ci/archive/20241108/202411081923.vkZSFxL2-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241108/202411081923.vkZSFxL2-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411081923.vkZSFxL2-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/gpu/drm/drm_client_setup.c:25:6: error: redefinition of 'drm_client_setup'
      25 | void drm_client_setup(struct drm_device *dev, const struct drm_format_info *format)
         |      ^~~~~~~~~~~~~~~~
   In file included from drivers/gpu/drm/drm_client_setup.c:3:
   include/drm/drm_client_setup.h:16:20: note: previous definition of 'drm_client_setup' with type 'void(struct drm_device *, const struct drm_format_info *)'
      16 | static inline void drm_client_setup(struct drm_device *dev,
         |                    ^~~~~~~~~~~~~~~~
>> drivers/gpu/drm/drm_client_setup.c:43:6: error: redefinition of 'drm_client_setup_with_fourcc'
      43 | void drm_client_setup_with_fourcc(struct drm_device *dev, u32 fourcc)
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
   In file included from drivers/gpu/drm/drm_client_setup.c:3:
   include/drm/drm_client_setup.h:19:20: note: previous definition of 'drm_client_setup_with_fourcc' with type 'void(struct drm_device *, u32)' {aka 'void(struct drm_device *, unsigned int)'}
      19 | static inline void drm_client_setup_with_fourcc(struct drm_device *dev, u32 fourcc)
         |                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/gpu/drm/drm_client_setup.c:60:6: error: redefinition of 'drm_client_setup_with_color_mode'
      60 | void drm_client_setup_with_color_mode(struct drm_device *dev, unsigned int color_mode)
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   In file included from drivers/gpu/drm/drm_client_setup.c:3:
   include/drm/drm_client_setup.h:21:20: note: previous definition of 'drm_client_setup_with_color_mode' with type 'void(struct drm_device *, unsigned int)'
      21 | static inline void drm_client_setup_with_color_mode(struct drm_device *dev,
         |                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/drm_client_setup +25 drivers/gpu/drm/drm_client_setup.c

d07fdf9225922d Thomas Zimmermann 2024-09-24   8  
d07fdf9225922d Thomas Zimmermann 2024-09-24   9  /**
d07fdf9225922d Thomas Zimmermann 2024-09-24  10   * drm_client_setup() - Setup in-kernel DRM clients
d07fdf9225922d Thomas Zimmermann 2024-09-24  11   * @dev: DRM device
d07fdf9225922d Thomas Zimmermann 2024-09-24  12   * @format: Preferred pixel format for the device. Use NULL, unless
d07fdf9225922d Thomas Zimmermann 2024-09-24  13   *          there is clearly a driver-preferred format.
d07fdf9225922d Thomas Zimmermann 2024-09-24  14   *
d07fdf9225922d Thomas Zimmermann 2024-09-24  15   * This function sets up the in-kernel DRM clients. Restore, hotplug
d07fdf9225922d Thomas Zimmermann 2024-09-24  16   * events and teardown are all taken care of.
d07fdf9225922d Thomas Zimmermann 2024-09-24  17   *
d07fdf9225922d Thomas Zimmermann 2024-09-24  18   * Drivers should call drm_client_setup() after registering the new
d07fdf9225922d Thomas Zimmermann 2024-09-24  19   * DRM device with drm_dev_register(). This function is safe to call
d07fdf9225922d Thomas Zimmermann 2024-09-24  20   * even when there are no connectors present. Setup will be retried
d07fdf9225922d Thomas Zimmermann 2024-09-24  21   * on the next hotplug event.
d07fdf9225922d Thomas Zimmermann 2024-09-24  22   *
d07fdf9225922d Thomas Zimmermann 2024-09-24  23   * The clients are destroyed by drm_dev_unregister().
d07fdf9225922d Thomas Zimmermann 2024-09-24  24   */
d07fdf9225922d Thomas Zimmermann 2024-09-24 @25  void drm_client_setup(struct drm_device *dev, const struct drm_format_info *format)
d07fdf9225922d Thomas Zimmermann 2024-09-24  26  {
d07fdf9225922d Thomas Zimmermann 2024-09-24  27  	int ret;
d07fdf9225922d Thomas Zimmermann 2024-09-24  28  
d07fdf9225922d Thomas Zimmermann 2024-09-24  29  	ret = drm_fbdev_client_setup(dev, format);
d07fdf9225922d Thomas Zimmermann 2024-09-24  30  	if (ret)
d07fdf9225922d Thomas Zimmermann 2024-09-24  31  		drm_warn(dev, "Failed to set up DRM client; error %d\n", ret);
d07fdf9225922d Thomas Zimmermann 2024-09-24  32  }
d07fdf9225922d Thomas Zimmermann 2024-09-24  33  EXPORT_SYMBOL(drm_client_setup);
d07fdf9225922d Thomas Zimmermann 2024-09-24  34  
d07fdf9225922d Thomas Zimmermann 2024-09-24  35  /**
d07fdf9225922d Thomas Zimmermann 2024-09-24  36   * drm_client_setup_with_fourcc() - Setup in-kernel DRM clients for color mode
d07fdf9225922d Thomas Zimmermann 2024-09-24  37   * @dev: DRM device
d07fdf9225922d Thomas Zimmermann 2024-09-24  38   * @fourcc: Preferred pixel format as 4CC code for the device
d07fdf9225922d Thomas Zimmermann 2024-09-24  39   *
d07fdf9225922d Thomas Zimmermann 2024-09-24  40   * This function sets up the in-kernel DRM clients. It is equivalent
d07fdf9225922d Thomas Zimmermann 2024-09-24  41   * to drm_client_setup(), but expects a 4CC code as second argument.
d07fdf9225922d Thomas Zimmermann 2024-09-24  42   */
d07fdf9225922d Thomas Zimmermann 2024-09-24 @43  void drm_client_setup_with_fourcc(struct drm_device *dev, u32 fourcc)
d07fdf9225922d Thomas Zimmermann 2024-09-24  44  {
d07fdf9225922d Thomas Zimmermann 2024-09-24  45  	drm_client_setup(dev, drm_format_info(fourcc));
d07fdf9225922d Thomas Zimmermann 2024-09-24  46  }
d07fdf9225922d Thomas Zimmermann 2024-09-24  47  EXPORT_SYMBOL(drm_client_setup_with_fourcc);
d07fdf9225922d Thomas Zimmermann 2024-09-24  48  
d07fdf9225922d Thomas Zimmermann 2024-09-24  49  /**
d07fdf9225922d Thomas Zimmermann 2024-09-24  50   * drm_client_setup_with_color_mode() - Setup in-kernel DRM clients for color mode
d07fdf9225922d Thomas Zimmermann 2024-09-24  51   * @dev: DRM device
d07fdf9225922d Thomas Zimmermann 2024-09-24  52   * @color_mode: Preferred color mode for the device
d07fdf9225922d Thomas Zimmermann 2024-09-24  53   *
d07fdf9225922d Thomas Zimmermann 2024-09-24  54   * This function sets up the in-kernel DRM clients. It is equivalent
d07fdf9225922d Thomas Zimmermann 2024-09-24  55   * to drm_client_setup(), but expects a color mode as second argument.
d07fdf9225922d Thomas Zimmermann 2024-09-24  56   *
d07fdf9225922d Thomas Zimmermann 2024-09-24  57   * Do not use this function in new drivers. Prefer drm_client_setup() with a
d07fdf9225922d Thomas Zimmermann 2024-09-24  58   * format of NULL.
d07fdf9225922d Thomas Zimmermann 2024-09-24  59   */
d07fdf9225922d Thomas Zimmermann 2024-09-24 @60  void drm_client_setup_with_color_mode(struct drm_device *dev, unsigned int color_mode)
d07fdf9225922d Thomas Zimmermann 2024-09-24  61  {
d07fdf9225922d Thomas Zimmermann 2024-09-24  62  	u32 fourcc = drm_driver_color_mode_format(dev, color_mode);
d07fdf9225922d Thomas Zimmermann 2024-09-24  63  
d07fdf9225922d Thomas Zimmermann 2024-09-24  64  	drm_client_setup_with_fourcc(dev, fourcc);
d07fdf9225922d Thomas Zimmermann 2024-09-24  65  }
d07fdf9225922d Thomas Zimmermann 2024-09-24  66  EXPORT_SYMBOL(drm_client_setup_with_color_mode);
dadd28d4142f9a Thomas Zimmermann 2024-10-14  67  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

[PATCH v7 3/7] drm/log: Introduce a new boot logger to draw the kmsg on the screen

[Jocelyn Falempe]

drm_log is a simple logger that uses the drm_client API to print the
kmsg boot log on the screen. This is not a full replacement to fbcon,
as it will only print the kmsg. It will never handle user input, or a
terminal because this is better done in userspace.

Design decisions:
 * It uses the drm_client API, so it should work on all drm drivers
   from the start.
 * It doesn't scroll the message, that way it doesn't need to redraw
   the whole screen for each new message.
   It also means it doesn't have to keep drawn messages in memory, to
   redraw them when scrolling.
 * It uses the new non-blocking console API, so it should work well
   with PREEMPT_RT.

This patch also adds a Kconfig menu to select the drm client to use.
It can be overwritten on the kernel command line with:
drm_client_lib.default=log or drm_client_lib.default=fbdev

Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de> # console API
---

v2:
 * Use vmap_local() api, with that change, I've tested it successfully on simpledrm, virtio-gpu, amdgpu, and nouveau.
 * Stop drawing when the drm_master is taken. This avoid wasting CPU cycle if the buffer is not visible.
 * Use deferred probe. Only do the probe the first time there is a log to draw. With this, if you boot with quiet, drm_log won't do any modeset.
 * Add color support for the timestamp prefix, like what dmesg does.
 * Add build dependency on  disabling the fbdev emulation, as they are both drm_client, and there is no way to choose which one gets the focus.

v3:
 * Remove the work thread and circular buffer, and use the new write_thread() console API.
 * Register a console for each drm driver.

v4:
 * Can be built as a module, even if that's not really useful.
 * Rebased on top of "drm: Introduce DRM client library" series from Thomas Zimmermann.
 * Add a Kconfig menu to choose between drm client.
 
v5:
 * Build drm_log in drm_client_lib module, to avoid circular dependency.

 drivers/gpu/drm/Kconfig            |  46 ++++
 drivers/gpu/drm/Makefile           |   1 +
 drivers/gpu/drm/drm_client_setup.c |  18 +-
 drivers/gpu/drm/drm_log.c          | 370 +++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_log.h          |  11 +
 5 files changed, 443 insertions(+), 3 deletions(-)
 create mode 100644 drivers/gpu/drm/drm_log.c
 create mode 100644 drivers/gpu/drm/drm_log.h

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index eabedfc11061c..63b78935ef2ed 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -292,6 +292,52 @@ config DRM_FBDEV_LEAK_PHYS_SMEM
 	  If in doubt, say "N" or spread the word to your closed source
 	  library vendor.
 
+config DRM_LOG
+	bool "Print the kernel boot message on the screen"
+	depends on DRM_CLIENT_SELECTION
+	select DRM_DRAW
+	select DRM_CLIENT_SETUP
+	help
+	  This enable a drm logger, that will print the kernel messages to the
+	  screen until the userspace is ready to take over.
+
+	  If you only need logs, but no terminal, or if you prefer userspace
+	  terminal, say "Y".
+
+choice
+	prompt "Default DRM Client"
+	depends on DRM_CLIENT_SELECTION
+	default DRM_CLIENT_DEFAULT_FBDEV
+	help
+	  Selects the default drm client.
+
+	  The selection made here can be overridden by using the kernel
+	  command line 'drm_client_lib.default=fbdev' option.
+
+config DRM_CLIENT_DEFAULT_FBDEV
+	bool "fbdev"
+	depends on DRM_FBDEV_EMULATION
+	help
+	  Use fbdev emulation as default drm client. This is needed to have
+	  fbcon on top of a drm driver.
+
+config DRM_CLIENT_DEFAULT_LOG
+	bool "log"
+	depends on DRM_LOG
+	help
+	  Use drm log as default drm client. This will display boot logs on the
+	  screen, but doesn't implement a full terminal. For that you will need
+	  a userspace terminal using drm/kms.
+
+endchoice
+
+config DRM_CLIENT_DEFAULT
+       string
+       depends on DRM_CLIENT
+       default "fbdev" if DRM_CLIENT_DEFAULT_FBDEV
+       default "log" if DRM_CLIENT_DEFAULT_LOG
+       default ""
+
 endmenu
 
 config DRM_LOAD_EDID_FIRMWARE
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 68a0a679a7b93..d4c028e839367 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -155,6 +155,7 @@ obj-$(CONFIG_DRM_KMS_HELPER) += drm_kms_helper.o
 
 drm_client_lib-y := drm_client_setup.o
 drm_client_lib-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fbdev_client.o
+drm_client_lib-$(CONFIG_DRM_LOG) += drm_log.o
 obj-$(CONFIG_DRM_CLIENT_LIB) += drm_client_lib.o
 
 #
diff --git a/drivers/gpu/drm/drm_client_setup.c b/drivers/gpu/drm/drm_client_setup.c
index c14221ca5a0d8..fa44dbee3defc 100644
--- a/drivers/gpu/drm/drm_client_setup.c
+++ b/drivers/gpu/drm/drm_client_setup.c
@@ -6,6 +6,14 @@
 #include <drm/drm_fourcc.h>
 #include <drm/drm_print.h>
 
+#include "drm_log.h"
+
+static char drm_client_default[16] = CONFIG_DRM_CLIENT_DEFAULT;
+module_param_string(client, drm_client_default, sizeof(drm_client_default), 0444);
+MODULE_PARM_DESC(client,
+		 "Choose which drm client to start, default is"
+		 CONFIG_DRM_CLIENT_DEFAULT "]");
+
 /**
  * drm_client_setup() - Setup in-kernel DRM clients
  * @dev: DRM device
@@ -26,9 +34,13 @@ void drm_client_setup(struct drm_device *dev, const struct drm_format_info *form
 {
 	int ret;
 
-	ret = drm_fbdev_client_setup(dev, format);
-	if (ret)
-		drm_warn(dev, "Failed to set up DRM client; error %d\n", ret);
+	if (!strcmp(drm_client_default, "log")) {
+		drm_log_register(dev);
+	} else if (!strcmp(drm_client_default, "fbdev")) {
+		ret = drm_fbdev_client_setup(dev, format);
+		if (ret)
+			drm_warn(dev, "Failed to set up DRM client; error %d\n", ret);
+	}
 }
 EXPORT_SYMBOL(drm_client_setup);
 
diff --git a/drivers/gpu/drm/drm_log.c b/drivers/gpu/drm/drm_log.c
new file mode 100644
index 0000000000000..376ee173d99d9
--- /dev/null
+++ b/drivers/gpu/drm/drm_log.c
@@ -0,0 +1,370 @@
+// SPDX-License-Identifier: GPL-2.0 or MIT
+/*
+ * Copyright (c) 2024 Red Hat.
+ * Author: Jocelyn Falempe <jfalempe@redhat.com>
+ */
+
+#include <linux/console.h>
+#include <linux/font.h>
+#include <linux/init.h>
+#include <linux/iosys-map.h>
+#include <linux/module.h>
+#include <linux/types.h>
+
+#include <drm/drm_client.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_framebuffer.h>
+#include <drm/drm_print.h>
+
+#include "drm_draw.h"
+#include "drm_log.h"
+
+MODULE_AUTHOR("Jocelyn Falempe");
+MODULE_DESCRIPTION("DRM boot logger");
+MODULE_LICENSE("GPL");
+
+/**
+ * DOC: overview
+ *
+ * This is a simple graphic logger, to print the kernel message on screen, until
+ * a userspace application is able to take over.
+ * It is only for debugging purpose.
+ */
+
+struct drm_log_scanout {
+	struct drm_client_buffer *buffer;
+	const struct font_desc *font;
+	u32 rows;
+	u32 columns;
+	u32 line;
+	u32 format;
+	u32 px_width;
+	u32 front_color;
+};
+
+struct drm_log {
+	struct mutex lock;
+	struct drm_client_dev client;
+	struct console con;
+	bool probed;
+	u32 n_scanout;
+	struct drm_log_scanout *scanout;
+};
+
+static struct drm_log *client_to_drm_log(struct drm_client_dev *client)
+{
+	return container_of(client, struct drm_log, client);
+}
+
+static struct drm_log *console_to_drm_log(struct console *con)
+{
+	return container_of(con, struct drm_log, con);
+}
+
+static void drm_log_blit(struct iosys_map *dst, unsigned int dst_pitch,
+			 const u8 *src, unsigned int src_pitch,
+			 u32 height, u32 width, u32 scale, u32 px_width, u32 color)
+{
+	switch (px_width) {
+	case 2:
+		drm_draw_blit16(dst, dst_pitch, src, src_pitch, height, width, scale, color);
+		break;
+	case 3:
+		drm_draw_blit24(dst, dst_pitch, src, src_pitch, height, width, scale, color);
+		break;
+	case 4:
+		drm_draw_blit32(dst, dst_pitch, src, src_pitch, height, width, scale, color);
+		break;
+	default:
+		WARN_ONCE(1, "Can't blit with pixel width %d\n", px_width);
+	}
+}
+
+static void drm_log_clear_line(struct drm_log_scanout *scanout, u32 line)
+{
+	struct drm_framebuffer *fb = scanout->buffer->fb;
+	unsigned long height = scanout->font->height;
+	struct iosys_map map;
+	struct drm_rect r = DRM_RECT_INIT(0, line * height, fb->width, height);
+
+	if (drm_client_buffer_vmap_local(scanout->buffer, &map))
+		return;
+	iosys_map_memset(&map, r.y1 * fb->pitches[0], 0, height * fb->pitches[0]);
+	drm_client_buffer_vunmap_local(scanout->buffer);
+	drm_client_framebuffer_flush(scanout->buffer, &r);
+}
+
+static void drm_log_draw_line(struct drm_log_scanout *scanout, const char *s,
+			      unsigned int len)
+{
+	struct drm_framebuffer *fb = scanout->buffer->fb;
+	struct iosys_map map;
+	const struct font_desc *font = scanout->font;
+	size_t font_pitch = DIV_ROUND_UP(font->width, 8);
+	const u8 *src;
+	u32 px_width = fb->format->cpp[0];
+	struct drm_rect r = DRM_RECT_INIT(0, scanout->line * font->height,
+					  fb->width, (scanout->line + 1) * font->height);
+	u32 i;
+
+	if (drm_client_buffer_vmap_local(scanout->buffer, &map))
+		return;
+
+	iosys_map_incr(&map, r.y1 * fb->pitches[0]);
+	for (i = 0; i < len && i < scanout->columns; i++) {
+		src = drm_draw_get_char_bitmap(font, s[i], font_pitch);
+		drm_log_blit(&map, fb->pitches[0], src, font_pitch, font->height, font->width,
+			     1, px_width, scanout->front_color);
+		iosys_map_incr(&map, font->width * px_width);
+	}
+
+	scanout->line++;
+	if (scanout->line >= scanout->rows)
+		scanout->line = 0;
+	drm_client_buffer_vunmap_local(scanout->buffer);
+	drm_client_framebuffer_flush(scanout->buffer, &r);
+}
+
+static void drm_log_draw_new_line(struct drm_log_scanout *scanout,
+				  const char *s, unsigned int len)
+{
+	if (scanout->line == 0) {
+		drm_log_clear_line(scanout, 0);
+		drm_log_clear_line(scanout, 1);
+		drm_log_clear_line(scanout, 2);
+	} else if (scanout->line + 2 < scanout->rows)
+		drm_log_clear_line(scanout, scanout->line + 2);
+
+	drm_log_draw_line(scanout, s, len);
+}
+
+static void drm_log_draw_kmsg_record(struct drm_log_scanout *scanout,
+				     const char *s, unsigned int len)
+{
+	/* do not print the ending \n character */
+	if (s[len - 1] == '\n')
+		len--;
+
+	while (len > scanout->columns) {
+		drm_log_draw_new_line(scanout, s, scanout->columns);
+		s += scanout->columns;
+		len -= scanout->columns;
+	}
+	if (len)
+		drm_log_draw_new_line(scanout, s, len);
+}
+
+static u32 drm_log_find_usable_format(struct drm_plane *plane)
+{
+	int i;
+
+	for (i = 0; i < plane->format_count; i++)
+		if (drm_draw_color_from_xrgb8888(0xffffff, plane->format_types[i]) != 0)
+			return plane->format_types[i];
+	return DRM_FORMAT_INVALID;
+}
+
+static int drm_log_setup_modeset(struct drm_client_dev *client,
+				 struct drm_mode_set *mode_set,
+				 struct drm_log_scanout *scanout)
+{
+	struct drm_crtc *crtc = mode_set->crtc;
+	u32 width = mode_set->mode->hdisplay;
+	u32 height = mode_set->mode->vdisplay;
+	u32 format;
+
+	scanout->font = get_default_font(width, height, NULL, NULL);
+	if (!scanout->font)
+		return -ENOENT;
+
+	format = drm_log_find_usable_format(crtc->primary);
+	if (format == DRM_FORMAT_INVALID)
+		return -EINVAL;
+
+	scanout->buffer = drm_client_framebuffer_create(client, width, height, format);
+	if (IS_ERR(scanout->buffer)) {
+		drm_warn(client->dev, "drm_log can't create framebuffer %d %d %p4cc\n",
+			 width, height, &format);
+		return -ENOMEM;
+	}
+	mode_set->fb = scanout->buffer->fb;
+	scanout->rows = height / scanout->font->height;
+	scanout->columns = width / scanout->font->width;
+	scanout->front_color = drm_draw_color_from_xrgb8888(0xffffff, format);
+	return 0;
+}
+
+static int drm_log_count_modeset(struct drm_client_dev *client)
+{
+	struct drm_mode_set *mode_set;
+	int count = 0;
+
+	mutex_lock(&client->modeset_mutex);
+	drm_client_for_each_modeset(mode_set, client)
+		count++;
+	mutex_unlock(&client->modeset_mutex);
+	return count;
+}
+
+static void drm_log_init_client(struct drm_log *dlog)
+{
+	struct drm_client_dev *client = &dlog->client;
+	struct drm_mode_set *mode_set;
+	int i, max_modeset;
+	int n_modeset = 0;
+
+	dlog->probed = true;
+
+	if (drm_client_modeset_probe(client, 0, 0))
+		return;
+
+	max_modeset = drm_log_count_modeset(client);
+	if (!max_modeset)
+		return;
+
+	dlog->scanout = kcalloc(max_modeset, sizeof(*dlog->scanout), GFP_KERNEL);
+	if (!dlog->scanout)
+		return;
+
+	mutex_lock(&client->modeset_mutex);
+	drm_client_for_each_modeset(mode_set, client) {
+		if (!mode_set->mode)
+			continue;
+		if (drm_log_setup_modeset(client, mode_set, &dlog->scanout[n_modeset]))
+			continue;
+		n_modeset++;
+	}
+	mutex_unlock(&client->modeset_mutex);
+	if (n_modeset == 0)
+		goto err_nomodeset;
+
+	if (drm_client_modeset_commit(client))
+		goto err_failed_commit;
+
+	dlog->n_scanout = n_modeset;
+	return;
+
+err_failed_commit:
+	for (i = 0; i < n_modeset; i++)
+		drm_client_framebuffer_delete(dlog->scanout[i].buffer);
+
+err_nomodeset:
+	kfree(dlog->scanout);
+	dlog->scanout = NULL;
+}
+
+static void drm_log_free_scanout(struct drm_client_dev *client)
+{
+	struct drm_log *dlog = client_to_drm_log(client);
+	int i;
+
+	if (dlog->n_scanout) {
+		for (i = 0; i < dlog->n_scanout; i++)
+			drm_client_framebuffer_delete(dlog->scanout[i].buffer);
+		dlog->n_scanout = 0;
+		kfree(dlog->scanout);
+		dlog->scanout = NULL;
+	}
+}
+
+static void drm_log_client_unregister(struct drm_client_dev *client)
+{
+	struct drm_log *dlog = client_to_drm_log(client);
+	struct drm_device *dev = client->dev;
+
+	unregister_console(&dlog->con);
+
+	mutex_lock(&dlog->lock);
+	drm_log_free_scanout(client);
+	drm_client_release(client);
+	mutex_unlock(&dlog->lock);
+	kfree(dlog);
+	drm_info(dev, "Unregistered with drm log\n");
+}
+
+static int drm_log_client_hotplug(struct drm_client_dev *client)
+{
+	struct drm_log *dlog = client_to_drm_log(client);
+
+	mutex_lock(&dlog->lock);
+	drm_log_free_scanout(client);
+	dlog->probed = false;
+	mutex_unlock(&dlog->lock);
+	return 0;
+}
+
+static const struct drm_client_funcs drm_log_client_funcs = {
+	.owner		= THIS_MODULE,
+	.unregister	= drm_log_client_unregister,
+	.hotplug	= drm_log_client_hotplug,
+};
+
+static void drm_log_write_thread(struct console *con, struct nbcon_write_context *wctxt)
+{
+	struct drm_log *dlog = console_to_drm_log(con);
+	int i;
+
+	if (!dlog->probed)
+		drm_log_init_client(dlog);
+
+	for (i = 0; i < dlog->n_scanout; i++)
+		drm_log_draw_kmsg_record(&dlog->scanout[i], wctxt->outbuf, wctxt->len);
+}
+
+static void drm_log_lock(struct console *con, unsigned long *flags)
+{
+	struct drm_log *dlog = console_to_drm_log(con);
+
+	mutex_lock(&dlog->lock);
+	migrate_disable();
+}
+
+static void drm_log_unlock(struct console *con, unsigned long flags)
+{
+	struct drm_log *dlog = console_to_drm_log(con);
+
+	migrate_enable();
+	mutex_unlock(&dlog->lock);
+}
+
+static void drm_log_register_console(struct console *con)
+{
+	strscpy(con->name, "drm_log");
+	con->write_thread = drm_log_write_thread;
+	con->device_lock = drm_log_lock;
+	con->device_unlock = drm_log_unlock;
+	con->flags = CON_PRINTBUFFER | CON_NBCON;
+	con->index = -1;
+
+	register_console(con);
+}
+
+/**
+ * drm_log_register() - Register a drm device to drm_log
+ * @dev: the drm device to register.
+ */
+void drm_log_register(struct drm_device *dev)
+{
+	struct drm_log *new;
+
+	new = kzalloc(sizeof(*new), GFP_KERNEL);
+	if (!new)
+		goto err_warn;
+
+	mutex_init(&new->lock);
+	if (drm_client_init(dev, &new->client, "drm_log", &drm_log_client_funcs))
+		goto err_free;
+
+	drm_client_register(&new->client);
+
+	drm_log_register_console(&new->con);
+
+	drm_info(dev, "Registered with drm log as %s\n", new->con.name);
+	return;
+
+err_free:
+	kfree(new);
+err_warn:
+	drm_warn(dev, "Failed to register with drm log\n");
+}
diff --git a/drivers/gpu/drm/drm_log.h b/drivers/gpu/drm/drm_log.h
new file mode 100644
index 0000000000000..3a4ea81509474
--- /dev/null
+++ b/drivers/gpu/drm/drm_log.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 or MIT */
+#ifndef __DRM_LOG_H__
+#define __DRM_LOG_H__
+
+#ifdef CONFIG_DRM_LOG
+void drm_log_register(struct drm_device *dev);
+#else
+static inline void drm_log_register(struct drm_device *dev) {}
+#endif
+
+#endif
-- 
2.47.0

Re: [PATCH v7 3/7] drm/log: Introduce a new boot logger to draw the kmsg on the screen

[kernel test robot]

Hi Jocelyn,

kernel test robot noticed the following build errors:

[auto build test ERROR on baf4afc5831438b35de4b0e951b9cd58435a6d99]

url:    https://github.com/intel-lab-lkp/linux/commits/Jocelyn-Falempe/drm-panic-Move-drawing-functions-to-drm_draw/20241108-162222
base:   baf4afc5831438b35de4b0e951b9cd58435a6d99
patch link:    https://lore.kernel.org/r/20241108082025.1004653-4-jfalempe%40redhat.com
patch subject: [PATCH v7 3/7] drm/log: Introduce a new boot logger to draw the kmsg on the screen
config: x86_64-buildonly-randconfig-002-20241108 (https://download.01.org/0day-ci/archive/20241108/202411082006.DB7Dlk06-lkp@intel.com/config)
compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241108/202411082006.DB7Dlk06-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411082006.DB7Dlk06-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/gpu/drm/drm_client_setup.c:11:38: error: use of undeclared identifier 'CONFIG_DRM_CLIENT_DEFAULT'
      11 | static char drm_client_default[16] = CONFIG_DRM_CLIENT_DEFAULT;
         |                                      ^
>> drivers/gpu/drm/drm_client_setup.c:15:4: error: expected ';' after top level declarator
      15 |                  CONFIG_DRM_CLIENT_DEFAULT "]");
         |                  ^
   drivers/gpu/drm/drm_client_setup.c:33:6: error: redefinition of 'drm_client_setup'
      33 | void drm_client_setup(struct drm_device *dev, const struct drm_format_info *format)
         |      ^
   include/drm/drm_client_setup.h:16:20: note: previous definition is here
      16 | static inline void drm_client_setup(struct drm_device *dev,
         |                    ^
   drivers/gpu/drm/drm_client_setup.c:55:6: error: redefinition of 'drm_client_setup_with_fourcc'
      55 | void drm_client_setup_with_fourcc(struct drm_device *dev, u32 fourcc)
         |      ^
   include/drm/drm_client_setup.h:19:20: note: previous definition is here
      19 | static inline void drm_client_setup_with_fourcc(struct drm_device *dev, u32 fourcc)
         |                    ^
   drivers/gpu/drm/drm_client_setup.c:72:6: error: redefinition of 'drm_client_setup_with_color_mode'
      72 | void drm_client_setup_with_color_mode(struct drm_device *dev, unsigned int color_mode)
         |      ^
   include/drm/drm_client_setup.h:21:20: note: previous definition is here
      21 | static inline void drm_client_setup_with_color_mode(struct drm_device *dev,
         |                    ^
   5 errors generated.


vim +/CONFIG_DRM_CLIENT_DEFAULT +11 drivers/gpu/drm/drm_client_setup.c

    10	
  > 11	static char drm_client_default[16] = CONFIG_DRM_CLIENT_DEFAULT;
    12	module_param_string(client, drm_client_default, sizeof(drm_client_default), 0444);
    13	MODULE_PARM_DESC(client,
    14			 "Choose which drm client to start, default is"
  > 15			 CONFIG_DRM_CLIENT_DEFAULT "]");
    16	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v7 3/7] drm/log: Introduce a new boot logger to draw the kmsg on the screen

[kernel test robot]

Hi Jocelyn,

kernel test robot noticed the following build errors:

[auto build test ERROR on baf4afc5831438b35de4b0e951b9cd58435a6d99]

url:    https://github.com/intel-lab-lkp/linux/commits/Jocelyn-Falempe/drm-panic-Move-drawing-functions-to-drm_draw/20241108-162222
base:   baf4afc5831438b35de4b0e951b9cd58435a6d99
patch link:    https://lore.kernel.org/r/20241108082025.1004653-4-jfalempe%40redhat.com
patch subject: [PATCH v7 3/7] drm/log: Introduce a new boot logger to draw the kmsg on the screen
config: x86_64-defconfig (https://download.01.org/0day-ci/archive/20241108/202411082034.Lnxy55Wm-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241108/202411082034.Lnxy55Wm-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411082034.Lnxy55Wm-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/gpu/drm/drm_client_setup.c:11:38: error: 'CONFIG_DRM_CLIENT_DEFAULT' undeclared here (not in a function); did you mean 'CONFIG_DRM_CLIENT_LIB'?
      11 | static char drm_client_default[16] = CONFIG_DRM_CLIENT_DEFAULT;
         |                                      ^~~~~~~~~~~~~~~~~~~~~~~~~
         |                                      CONFIG_DRM_CLIENT_LIB
   In file included from include/linux/module.h:22,
                    from include/linux/device/driver.h:21,
                    from include/linux/device.h:32,
                    from include/drm/drm_print.h:31,
                    from drivers/gpu/drm/drm_client_setup.c:7:
>> drivers/gpu/drm/drm_client_setup.c:15:18: error: expected ',' or ';' before 'CONFIG_DRM_CLIENT_DEFAULT'
      15 |                  CONFIG_DRM_CLIENT_DEFAULT "]");
         |                  ^~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/moduleparam.h:26:61: note: in definition of macro '__MODULE_INFO'
      26 |                 = __MODULE_INFO_PREFIX __stringify(tag) "=" info
         |                                                             ^~~~
   drivers/gpu/drm/drm_client_setup.c:13:1: note: in expansion of macro 'MODULE_PARM_DESC'
      13 | MODULE_PARM_DESC(client,
         | ^~~~~~~~~~~~~~~~
   drivers/gpu/drm/drm_client_setup.c:33:6: error: redefinition of 'drm_client_setup'
      33 | void drm_client_setup(struct drm_device *dev, const struct drm_format_info *format)
         |      ^~~~~~~~~~~~~~~~
   In file included from drivers/gpu/drm/drm_client_setup.c:3:
   include/drm/drm_client_setup.h:16:20: note: previous definition of 'drm_client_setup' with type 'void(struct drm_device *, const struct drm_format_info *)'
      16 | static inline void drm_client_setup(struct drm_device *dev,
         |                    ^~~~~~~~~~~~~~~~
   drivers/gpu/drm/drm_client_setup.c:55:6: error: redefinition of 'drm_client_setup_with_fourcc'
      55 | void drm_client_setup_with_fourcc(struct drm_device *dev, u32 fourcc)
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
   In file included from drivers/gpu/drm/drm_client_setup.c:3:
   include/drm/drm_client_setup.h:19:20: note: previous definition of 'drm_client_setup_with_fourcc' with type 'void(struct drm_device *, u32)' {aka 'void(struct drm_device *, unsigned int)'}
      19 | static inline void drm_client_setup_with_fourcc(struct drm_device *dev, u32 fourcc)
         |                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/gpu/drm/drm_client_setup.c:72:6: error: redefinition of 'drm_client_setup_with_color_mode'
      72 | void drm_client_setup_with_color_mode(struct drm_device *dev, unsigned int color_mode)
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   In file included from drivers/gpu/drm/drm_client_setup.c:3:
   include/drm/drm_client_setup.h:21:20: note: previous definition of 'drm_client_setup_with_color_mode' with type 'void(struct drm_device *, unsigned int)'
      21 | static inline void drm_client_setup_with_color_mode(struct drm_device *dev,
         |                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +11 drivers/gpu/drm/drm_client_setup.c

    10	
  > 11	static char drm_client_default[16] = CONFIG_DRM_CLIENT_DEFAULT;
    12	module_param_string(client, drm_client_default, sizeof(drm_client_default), 0444);
    13	MODULE_PARM_DESC(client,
    14			 "Choose which drm client to start, default is"
  > 15			 CONFIG_DRM_CLIENT_DEFAULT "]");
    16	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

[PATCH v7 4/7] drm/log: Do not draw if drm_master is taken

[Jocelyn Falempe]

When userspace takes drm_master, the drm_client buffer is no more
visible, so drm_log shouldn't waste CPU cycle to draw on it.

Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
---
 drivers/gpu/drm/drm_log.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_log.c b/drivers/gpu/drm/drm_log.c
index 376ee173d99d9..226e206e8b6a3 100644
--- a/drivers/gpu/drm/drm_log.c
+++ b/drivers/gpu/drm/drm_log.c
@@ -18,6 +18,7 @@
 #include <drm/drm_print.h>
 
 #include "drm_draw.h"
+#include "drm_internal.h"
 #include "drm_log.h"
 
 MODULE_AUTHOR("Jocelyn Falempe");
@@ -308,8 +309,13 @@ static void drm_log_write_thread(struct console *con, struct nbcon_write_context
 	if (!dlog->probed)
 		drm_log_init_client(dlog);
 
-	for (i = 0; i < dlog->n_scanout; i++)
-		drm_log_draw_kmsg_record(&dlog->scanout[i], wctxt->outbuf, wctxt->len);
+	/* Check that we are still the master before drawing */
+	if (drm_master_internal_acquire(dlog->client.dev)) {
+		drm_master_internal_release(dlog->client.dev);
+
+		for (i = 0; i < dlog->n_scanout; i++)
+			drm_log_draw_kmsg_record(&dlog->scanout[i], wctxt->outbuf, wctxt->len);
+	}
 }
 
 static void drm_log_lock(struct console *con, unsigned long *flags)
-- 
2.47.0

Re: [PATCH v7 4/7] drm/log: Do not draw if drm_master is taken

[Thomas Zimmermann]

Hi

Am 08.11.24 um 09:10 schrieb Jocelyn Falempe:
> When userspace takes drm_master, the drm_client buffer is no more
> visible, so drm_log shouldn't waste CPU cycle to draw on it.
>
> Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
> ---
>   drivers/gpu/drm/drm_log.c | 10 ++++++++--
>   1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_log.c b/drivers/gpu/drm/drm_log.c
> index 376ee173d99d9..226e206e8b6a3 100644
> --- a/drivers/gpu/drm/drm_log.c
> +++ b/drivers/gpu/drm/drm_log.c
> @@ -18,6 +18,7 @@
>   #include <drm/drm_print.h>
>   
>   #include "drm_draw.h"
> +#include "drm_internal.h"
>   #include "drm_log.h"
>   
>   MODULE_AUTHOR("Jocelyn Falempe");
> @@ -308,8 +309,13 @@ static void drm_log_write_thread(struct console *con, struct nbcon_write_context
>   	if (!dlog->probed)
>   		drm_log_init_client(dlog);
>   
> -	for (i = 0; i < dlog->n_scanout; i++)
> -		drm_log_draw_kmsg_record(&dlog->scanout[i], wctxt->outbuf, wctxt->len);
> +	/* Check that we are still the master before drawing */
> +	if (drm_master_internal_acquire(dlog->client.dev)) {

Just a note: it would be better to track this state in the client code 
and handle these locks automatically. But it's ok for now. It would 
require an overhaul of the fbdev helpers as well.

> +		drm_master_internal_release(dlog->client.dev);

Don't you have to release after drawing?

Best regards
Thomas


> +
> +		for (i = 0; i < dlog->n_scanout; i++)
> +			drm_log_draw_kmsg_record(&dlog->scanout[i], wctxt->outbuf, wctxt->len);
> +	}
>   }
>   
>   static void drm_log_lock(struct console *con, unsigned long *flags)

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)

Re: [PATCH v7 4/7] drm/log: Do not draw if drm_master is taken

[Jocelyn Falempe]

On 08/11/2024 14:33, Thomas Zimmermann wrote:
> Hi
> 
> Am 08.11.24 um 09:10 schrieb Jocelyn Falempe:
>> When userspace takes drm_master, the drm_client buffer is no more
>> visible, so drm_log shouldn't waste CPU cycle to draw on it.
>>
>> Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
>> ---
>>   drivers/gpu/drm/drm_log.c | 10 ++++++++--
>>   1 file changed, 8 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_log.c b/drivers/gpu/drm/drm_log.c
>> index 376ee173d99d9..226e206e8b6a3 100644
>> --- a/drivers/gpu/drm/drm_log.c
>> +++ b/drivers/gpu/drm/drm_log.c
>> @@ -18,6 +18,7 @@
>>   #include <drm/drm_print.h>
>>   #include "drm_draw.h"
>> +#include "drm_internal.h"
>>   #include "drm_log.h"
>>   MODULE_AUTHOR("Jocelyn Falempe");
>> @@ -308,8 +309,13 @@ static void drm_log_write_thread(struct console 
>> *con, struct nbcon_write_context
>>       if (!dlog->probed)
>>           drm_log_init_client(dlog);
>> -    for (i = 0; i < dlog->n_scanout; i++)
>> -        drm_log_draw_kmsg_record(&dlog->scanout[i], wctxt->outbuf, 
>> wctxt->len);
>> +    /* Check that we are still the master before drawing */
>> +    if (drm_master_internal_acquire(dlog->client.dev)) {
> 
> Just a note: it would be better to track this state in the client code 
> and handle these locks automatically. But it's ok for now. It would 
> require an overhaul of the fbdev helpers as well.
> 
>> +        drm_master_internal_release(dlog->client.dev);
> 
> Don't you have to release after drawing?

I'm not sure, the drawing code will only call 
drm_client_buffer_vmap_local() / unmap
and drm_client_framebuffer_flush(), and they don't require the master 
lock to be taken. I think master lock is needed only for modesetting.

Also the dlog->lock is taken by the console thread, so there are no race 
conditions with the drm_client callbacks (hotplug/suspend/resume).

> 
> Best regards
> Thomas
> 
> 
>> +
>> +        for (i = 0; i < dlog->n_scanout; i++)
>> +            drm_log_draw_kmsg_record(&dlog->scanout[i], wctxt- 
>> >outbuf, wctxt->len);
>> +    }
>>   }
>>   static void drm_log_lock(struct console *con, unsigned long *flags)
> 

[PATCH v7 5/7] drm/log: Color the timestamp, to improve readability

[Jocelyn Falempe]

Color the timesamp prefix, similar to dmesg.

Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
---
 drivers/gpu/drm/drm_log.c | 27 +++++++++++++++++++++------
 1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/drm_log.c b/drivers/gpu/drm/drm_log.c
index 226e206e8b6a3..635dff7b37ce5 100644
--- a/drivers/gpu/drm/drm_log.c
+++ b/drivers/gpu/drm/drm_log.c
@@ -42,6 +42,7 @@ struct drm_log_scanout {
 	u32 format;
 	u32 px_width;
 	u32 front_color;
+	u32 prefix_color;
 };
 
 struct drm_log {
@@ -97,7 +98,7 @@ static void drm_log_clear_line(struct drm_log_scanout *scanout, u32 line)
 }
 
 static void drm_log_draw_line(struct drm_log_scanout *scanout, const char *s,
-			      unsigned int len)
+			      unsigned int len, unsigned int prefix_len)
 {
 	struct drm_framebuffer *fb = scanout->buffer->fb;
 	struct iosys_map map;
@@ -114,9 +115,10 @@ static void drm_log_draw_line(struct drm_log_scanout *scanout, const char *s,
 
 	iosys_map_incr(&map, r.y1 * fb->pitches[0]);
 	for (i = 0; i < len && i < scanout->columns; i++) {
+		u32 color = (i < prefix_len) ? scanout->prefix_color : scanout->front_color;
 		src = drm_draw_get_char_bitmap(font, s[i], font_pitch);
 		drm_log_blit(&map, fb->pitches[0], src, font_pitch, font->height, font->width,
-			     1, px_width, scanout->front_color);
+			     1, px_width, color);
 		iosys_map_incr(&map, font->width * px_width);
 	}
 
@@ -128,7 +130,7 @@ static void drm_log_draw_line(struct drm_log_scanout *scanout, const char *s,
 }
 
 static void drm_log_draw_new_line(struct drm_log_scanout *scanout,
-				  const char *s, unsigned int len)
+				  const char *s, unsigned int len, unsigned int prefix_len)
 {
 	if (scanout->line == 0) {
 		drm_log_clear_line(scanout, 0);
@@ -137,23 +139,35 @@ static void drm_log_draw_new_line(struct drm_log_scanout *scanout,
 	} else if (scanout->line + 2 < scanout->rows)
 		drm_log_clear_line(scanout, scanout->line + 2);
 
-	drm_log_draw_line(scanout, s, len);
+	drm_log_draw_line(scanout, s, len, prefix_len);
 }
 
+/*
+ * Depends on print_time() in printk.c
+ * Timestamp is written with "[%5lu.%06lu]"
+ */
+#define TS_PREFIX_LEN 13
+
 static void drm_log_draw_kmsg_record(struct drm_log_scanout *scanout,
 				     const char *s, unsigned int len)
 {
+	u32 prefix_len = 0;
+
+	if (len > TS_PREFIX_LEN && s[0] == '[' && s[6] == '.' && s[TS_PREFIX_LEN] == ']')
+		prefix_len = TS_PREFIX_LEN + 1;
+
 	/* do not print the ending \n character */
 	if (s[len - 1] == '\n')
 		len--;
 
 	while (len > scanout->columns) {
-		drm_log_draw_new_line(scanout, s, scanout->columns);
+		drm_log_draw_new_line(scanout, s, scanout->columns, prefix_len);
 		s += scanout->columns;
 		len -= scanout->columns;
+		prefix_len = 0;
 	}
 	if (len)
-		drm_log_draw_new_line(scanout, s, len);
+		drm_log_draw_new_line(scanout, s, len, prefix_len);
 }
 
 static u32 drm_log_find_usable_format(struct drm_plane *plane)
@@ -193,6 +207,7 @@ static int drm_log_setup_modeset(struct drm_client_dev *client,
 	scanout->rows = height / scanout->font->height;
 	scanout->columns = width / scanout->font->width;
 	scanout->front_color = drm_draw_color_from_xrgb8888(0xffffff, format);
+	scanout->prefix_color = drm_draw_color_from_xrgb8888(0x4e9a06, format);
 	return 0;
 }
 
-- 
2.47.0

[PATCH v7 6/7] drm/log: Implement suspend/resume

[Jocelyn Falempe]

Normally the console is already suspended when the graphic driver
suspend callback is called, but if the parameter no_console_suspend
is set, it might still be active.
So call console_stop()/console_start() in the suspend/resume
callbacks, to make sure it won't try to write to the framebuffer
while the graphic driver is suspended.

Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Acked-by: Petr Mladek <pmladek@suse.com>
---

v6:
 * Use console_stop() and console_start() in the suspend/resume callback (Petr Mladek).


 drivers/gpu/drm/drm_log.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/gpu/drm/drm_log.c b/drivers/gpu/drm/drm_log.c
index 635dff7b37ce5..e6900c6b96436 100644
--- a/drivers/gpu/drm/drm_log.c
+++ b/drivers/gpu/drm/drm_log.c
@@ -310,10 +310,30 @@ static int drm_log_client_hotplug(struct drm_client_dev *client)
 	return 0;
 }
 
+static int drm_log_client_suspend(struct drm_client_dev *client, bool _console_lock)
+{
+	struct drm_log *dlog = client_to_drm_log(client);
+
+	console_stop(&dlog->con);
+
+	return 0;
+}
+
+static int drm_log_client_resume(struct drm_client_dev *client, bool _console_lock)
+{
+	struct drm_log *dlog = client_to_drm_log(client);
+
+	console_start(&dlog->con);
+
+	return 0;
+}
+
 static const struct drm_client_funcs drm_log_client_funcs = {
 	.owner		= THIS_MODULE,
 	.unregister	= drm_log_client_unregister,
 	.hotplug	= drm_log_client_hotplug,
+	.suspend	= drm_log_client_suspend,
+	.resume		= drm_log_client_resume,
 };
 
 static void drm_log_write_thread(struct console *con, struct nbcon_write_context *wctxt)
-- 
2.47.0

[PATCH v7 7/7] drm/log: Add integer scaling support

[Jocelyn Falempe]

Add a module parameter, to increase the font size for HiDPI screen.
Even with CONFIG_FONT_TER16x32, it can still be a bit small to read.
In this case, adding drm_log.scale=2 to your kernel command line will
double the character size.

Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
---

v5:
 * Change scale parameter to unsigned int (Jani Nikula)

 drivers/gpu/drm/drm_log.c | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/drm_log.c b/drivers/gpu/drm/drm_log.c
index e6900c6b96436..4dc7be2288ab7 100644
--- a/drivers/gpu/drm/drm_log.c
+++ b/drivers/gpu/drm/drm_log.c
@@ -25,6 +25,10 @@ MODULE_AUTHOR("Jocelyn Falempe");
 MODULE_DESCRIPTION("DRM boot logger");
 MODULE_LICENSE("GPL");
 
+static unsigned int scale = 1;
+module_param(scale, uint, 0444);
+MODULE_PARM_DESC(scale, "Integer scaling factor for drm_log, default is 1");
+
 /**
  * DOC: overview
  *
@@ -38,6 +42,8 @@ struct drm_log_scanout {
 	const struct font_desc *font;
 	u32 rows;
 	u32 columns;
+	u32 scaled_font_h;
+	u32 scaled_font_w;
 	u32 line;
 	u32 format;
 	u32 px_width;
@@ -66,7 +72,7 @@ static struct drm_log *console_to_drm_log(struct console *con)
 
 static void drm_log_blit(struct iosys_map *dst, unsigned int dst_pitch,
 			 const u8 *src, unsigned int src_pitch,
-			 u32 height, u32 width, u32 scale, u32 px_width, u32 color)
+			 u32 height, u32 width, u32 px_width, u32 color)
 {
 	switch (px_width) {
 	case 2:
@@ -86,7 +92,7 @@ static void drm_log_blit(struct iosys_map *dst, unsigned int dst_pitch,
 static void drm_log_clear_line(struct drm_log_scanout *scanout, u32 line)
 {
 	struct drm_framebuffer *fb = scanout->buffer->fb;
-	unsigned long height = scanout->font->height;
+	unsigned long height = scanout->scaled_font_h;
 	struct iosys_map map;
 	struct drm_rect r = DRM_RECT_INIT(0, line * height, fb->width, height);
 
@@ -106,8 +112,8 @@ static void drm_log_draw_line(struct drm_log_scanout *scanout, const char *s,
 	size_t font_pitch = DIV_ROUND_UP(font->width, 8);
 	const u8 *src;
 	u32 px_width = fb->format->cpp[0];
-	struct drm_rect r = DRM_RECT_INIT(0, scanout->line * font->height,
-					  fb->width, (scanout->line + 1) * font->height);
+	struct drm_rect r = DRM_RECT_INIT(0, scanout->line * scanout->scaled_font_h,
+					  fb->width, (scanout->line + 1) * scanout->scaled_font_h);
 	u32 i;
 
 	if (drm_client_buffer_vmap_local(scanout->buffer, &map))
@@ -117,9 +123,10 @@ static void drm_log_draw_line(struct drm_log_scanout *scanout, const char *s,
 	for (i = 0; i < len && i < scanout->columns; i++) {
 		u32 color = (i < prefix_len) ? scanout->prefix_color : scanout->front_color;
 		src = drm_draw_get_char_bitmap(font, s[i], font_pitch);
-		drm_log_blit(&map, fb->pitches[0], src, font_pitch, font->height, font->width,
-			     1, px_width, color);
-		iosys_map_incr(&map, font->width * px_width);
+		drm_log_blit(&map, fb->pitches[0], src, font_pitch,
+			     scanout->scaled_font_h, scanout->scaled_font_w,
+			     px_width, color);
+		iosys_map_incr(&map, scanout->scaled_font_w * px_width);
 	}
 
 	scanout->line++;
@@ -204,8 +211,10 @@ static int drm_log_setup_modeset(struct drm_client_dev *client,
 		return -ENOMEM;
 	}
 	mode_set->fb = scanout->buffer->fb;
-	scanout->rows = height / scanout->font->height;
-	scanout->columns = width / scanout->font->width;
+	scanout->scaled_font_h = scanout->font->height * scale;
+	scanout->scaled_font_w = scanout->font->width * scale;
+	scanout->rows = height / scanout->scaled_font_h;
+	scanout->columns = width / scanout->scaled_font_w;
 	scanout->front_color = drm_draw_color_from_xrgb8888(0xffffff, format);
 	scanout->prefix_color = drm_draw_color_from_xrgb8888(0x4e9a06, format);
 	return 0;
-- 
2.47.0

Re: [PATCH v7 7/7] drm/log: Add integer scaling support

[Thomas Zimmermann]

Hi


Am 08.11.24 um 09:10 schrieb Jocelyn Falempe:
> Add a module parameter, to increase the font size for HiDPI screen.
> Even with CONFIG_FONT_TER16x32, it can still be a bit small to read.
> In this case, adding drm_log.scale=2 to your kernel command line will
> double the character size.

Can't we have larger fonts instead?

Best regards
Thomas

>
> Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
> ---
>
> v5:
>   * Change scale parameter to unsigned int (Jani Nikula)
>
>   drivers/gpu/drm/drm_log.c | 27 ++++++++++++++++++---------
>   1 file changed, 18 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_log.c b/drivers/gpu/drm/drm_log.c
> index e6900c6b96436..4dc7be2288ab7 100644
> --- a/drivers/gpu/drm/drm_log.c
> +++ b/drivers/gpu/drm/drm_log.c
> @@ -25,6 +25,10 @@ MODULE_AUTHOR("Jocelyn Falempe");
>   MODULE_DESCRIPTION("DRM boot logger");
>   MODULE_LICENSE("GPL");
>   
> +static unsigned int scale = 1;
> +module_param(scale, uint, 0444);
> +MODULE_PARM_DESC(scale, "Integer scaling factor for drm_log, default is 1");
> +
>   /**
>    * DOC: overview
>    *
> @@ -38,6 +42,8 @@ struct drm_log_scanout {
>   	const struct font_desc *font;
>   	u32 rows;
>   	u32 columns;
> +	u32 scaled_font_h;
> +	u32 scaled_font_w;
>   	u32 line;
>   	u32 format;
>   	u32 px_width;
> @@ -66,7 +72,7 @@ static struct drm_log *console_to_drm_log(struct console *con)
>   
>   static void drm_log_blit(struct iosys_map *dst, unsigned int dst_pitch,
>   			 const u8 *src, unsigned int src_pitch,
> -			 u32 height, u32 width, u32 scale, u32 px_width, u32 color)
> +			 u32 height, u32 width, u32 px_width, u32 color)
>   {
>   	switch (px_width) {
>   	case 2:
> @@ -86,7 +92,7 @@ static void drm_log_blit(struct iosys_map *dst, unsigned int dst_pitch,
>   static void drm_log_clear_line(struct drm_log_scanout *scanout, u32 line)
>   {
>   	struct drm_framebuffer *fb = scanout->buffer->fb;
> -	unsigned long height = scanout->font->height;
> +	unsigned long height = scanout->scaled_font_h;
>   	struct iosys_map map;
>   	struct drm_rect r = DRM_RECT_INIT(0, line * height, fb->width, height);
>   
> @@ -106,8 +112,8 @@ static void drm_log_draw_line(struct drm_log_scanout *scanout, const char *s,
>   	size_t font_pitch = DIV_ROUND_UP(font->width, 8);
>   	const u8 *src;
>   	u32 px_width = fb->format->cpp[0];
> -	struct drm_rect r = DRM_RECT_INIT(0, scanout->line * font->height,
> -					  fb->width, (scanout->line + 1) * font->height);
> +	struct drm_rect r = DRM_RECT_INIT(0, scanout->line * scanout->scaled_font_h,
> +					  fb->width, (scanout->line + 1) * scanout->scaled_font_h);
>   	u32 i;
>   
>   	if (drm_client_buffer_vmap_local(scanout->buffer, &map))
> @@ -117,9 +123,10 @@ static void drm_log_draw_line(struct drm_log_scanout *scanout, const char *s,
>   	for (i = 0; i < len && i < scanout->columns; i++) {
>   		u32 color = (i < prefix_len) ? scanout->prefix_color : scanout->front_color;
>   		src = drm_draw_get_char_bitmap(font, s[i], font_pitch);
> -		drm_log_blit(&map, fb->pitches[0], src, font_pitch, font->height, font->width,
> -			     1, px_width, color);
> -		iosys_map_incr(&map, font->width * px_width);
> +		drm_log_blit(&map, fb->pitches[0], src, font_pitch,
> +			     scanout->scaled_font_h, scanout->scaled_font_w,
> +			     px_width, color);
> +		iosys_map_incr(&map, scanout->scaled_font_w * px_width);
>   	}
>   
>   	scanout->line++;
> @@ -204,8 +211,10 @@ static int drm_log_setup_modeset(struct drm_client_dev *client,
>   		return -ENOMEM;
>   	}
>   	mode_set->fb = scanout->buffer->fb;
> -	scanout->rows = height / scanout->font->height;
> -	scanout->columns = width / scanout->font->width;
> +	scanout->scaled_font_h = scanout->font->height * scale;
> +	scanout->scaled_font_w = scanout->font->width * scale;
> +	scanout->rows = height / scanout->scaled_font_h;
> +	scanout->columns = width / scanout->scaled_font_w;
>   	scanout->front_color = drm_draw_color_from_xrgb8888(0xffffff, format);
>   	scanout->prefix_color = drm_draw_color_from_xrgb8888(0x4e9a06, format);
>   	return 0;

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)

Re: [PATCH v7 7/7] drm/log: Add integer scaling support

[Jocelyn Falempe]

On 11/11/2024 14:06, Thomas Zimmermann wrote:
> Hi
> 
> 
> Am 08.11.24 um 09:10 schrieb Jocelyn Falempe:
>> Add a module parameter, to increase the font size for HiDPI screen.
>> Even with CONFIG_FONT_TER16x32, it can still be a bit small to read.
>> In this case, adding drm_log.scale=2 to your kernel command line will
>> double the character size.
> 
> Can't we have larger fonts instead?

Yes, that would be nice, but the largest font available currently is 16x32.
Also it's stored as raw bitmap, so bigger fonts will take much more memory.
For the drm_log use case, we don't need pixel-perfect glyph, so integer 
scaling is good enough.

Best regards,

-- 

Jocelyn


> 
> Best regards
> Thomas
> 
>>
>> Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
>> ---
>>
>> v5:
>>   * Change scale parameter to unsigned int (Jani Nikula)
>>
>>   drivers/gpu/drm/drm_log.c | 27 ++++++++++++++++++---------
>>   1 file changed, 18 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_log.c b/drivers/gpu/drm/drm_log.c
>> index e6900c6b96436..4dc7be2288ab7 100644
>> --- a/drivers/gpu/drm/drm_log.c
>> +++ b/drivers/gpu/drm/drm_log.c
>> @@ -25,6 +25,10 @@ MODULE_AUTHOR("Jocelyn Falempe");
>>   MODULE_DESCRIPTION("DRM boot logger");
>>   MODULE_LICENSE("GPL");
>> +static unsigned int scale = 1;
>> +module_param(scale, uint, 0444);
>> +MODULE_PARM_DESC(scale, "Integer scaling factor for drm_log, default 
>> is 1");
>> +
>>   /**
>>    * DOC: overview
>>    *
>> @@ -38,6 +42,8 @@ struct drm_log_scanout {
>>       const struct font_desc *font;
>>       u32 rows;
>>       u32 columns;
>> +    u32 scaled_font_h;
>> +    u32 scaled_font_w;
>>       u32 line;
>>       u32 format;
>>       u32 px_width;
>> @@ -66,7 +72,7 @@ static struct drm_log *console_to_drm_log(struct 
>> console *con)
>>   static void drm_log_blit(struct iosys_map *dst, unsigned int dst_pitch,
>>                const u8 *src, unsigned int src_pitch,
>> -             u32 height, u32 width, u32 scale, u32 px_width, u32 color)
>> +             u32 height, u32 width, u32 px_width, u32 color)
>>   {
>>       switch (px_width) {
>>       case 2:
>> @@ -86,7 +92,7 @@ static void drm_log_blit(struct iosys_map *dst, 
>> unsigned int dst_pitch,
>>   static void drm_log_clear_line(struct drm_log_scanout *scanout, u32 
>> line)
>>   {
>>       struct drm_framebuffer *fb = scanout->buffer->fb;
>> -    unsigned long height = scanout->font->height;
>> +    unsigned long height = scanout->scaled_font_h;
>>       struct iosys_map map;
>>       struct drm_rect r = DRM_RECT_INIT(0, line * height, fb->width, 
>> height);
>> @@ -106,8 +112,8 @@ static void drm_log_draw_line(struct 
>> drm_log_scanout *scanout, const char *s,
>>       size_t font_pitch = DIV_ROUND_UP(font->width, 8);
>>       const u8 *src;
>>       u32 px_width = fb->format->cpp[0];
>> -    struct drm_rect r = DRM_RECT_INIT(0, scanout->line * font->height,
>> -                      fb->width, (scanout->line + 1) * font->height);
>> +    struct drm_rect r = DRM_RECT_INIT(0, scanout->line * scanout- 
>> >scaled_font_h,
>> +                      fb->width, (scanout->line + 1) * scanout- 
>> >scaled_font_h);
>>       u32 i;
>>       if (drm_client_buffer_vmap_local(scanout->buffer, &map))
>> @@ -117,9 +123,10 @@ static void drm_log_draw_line(struct 
>> drm_log_scanout *scanout, const char *s,
>>       for (i = 0; i < len && i < scanout->columns; i++) {
>>           u32 color = (i < prefix_len) ? scanout->prefix_color : 
>> scanout->front_color;
>>           src = drm_draw_get_char_bitmap(font, s[i], font_pitch);
>> -        drm_log_blit(&map, fb->pitches[0], src, font_pitch, font- 
>> >height, font->width,
>> -                 1, px_width, color);
>> -        iosys_map_incr(&map, font->width * px_width);
>> +        drm_log_blit(&map, fb->pitches[0], src, font_pitch,
>> +                 scanout->scaled_font_h, scanout->scaled_font_w,
>> +                 px_width, color);
>> +        iosys_map_incr(&map, scanout->scaled_font_w * px_width);
>>       }
>>       scanout->line++;
>> @@ -204,8 +211,10 @@ static int drm_log_setup_modeset(struct 
>> drm_client_dev *client,
>>           return -ENOMEM;
>>       }
>>       mode_set->fb = scanout->buffer->fb;
>> -    scanout->rows = height / scanout->font->height;
>> -    scanout->columns = width / scanout->font->width;
>> +    scanout->scaled_font_h = scanout->font->height * scale;
>> +    scanout->scaled_font_w = scanout->font->width * scale;
>> +    scanout->rows = height / scanout->scaled_font_h;
>> +    scanout->columns = width / scanout->scaled_font_w;
>>       scanout->front_color = drm_draw_color_from_xrgb8888(0xffffff, 
>> format);
>>       scanout->prefix_color = drm_draw_color_from_xrgb8888(0x4e9a06, 
>> format);
>>       return 0;
>