1 files changed, 420 insertions, 0 deletions
diff --git a/drivers/gpu/drm/clients/drm_log.c b/drivers/gpu/drm/clients/drm_log.c
new file mode 100644
index 000000000000..d239f1e3c456
--- /dev/null
+++ b/drivers/gpu/drm/clients/drm_log.c
@@ -0,0 +1,420 @@
+// 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_client_internal.h"
+#include "drm_draw_internal.h"
+#include "drm_internal.h"
+
+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
+ *
+ * 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 scaled_font_h;
+	u32 scaled_font_w;
+	u32 line;
+	u32 format;
+	u32 px_width;
+	u32 front_color;
+	u32 prefix_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 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->scaled_font_h;
+	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, unsigned int prefix_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 * scanout->scaled_font_h,
+					  fb->width, (scanout->line + 1) * scanout->scaled_font_h);
+	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++) {
+		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,
+			     scanout->scaled_font_h, scanout->scaled_font_w,
+			     px_width, color);
+		iosys_map_incr(&map, scanout->scaled_font_w * 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, unsigned int prefix_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, 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, prefix_len);
+		s += scanout->columns;
+		len -= scanout->columns;
+		prefix_len = 0;
+	}
+	if (len)
+		drm_log_draw_new_line(scanout, s, len, prefix_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->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;
+}
+
+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_dbg(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 int drm_log_client_suspend(struct drm_client_dev *client, bool _console_lock)
+{
+	struct drm_log *dlog = client_to_drm_log(client);
+
+	console_suspend(&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_resume(&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)
+{
+	struct drm_log *dlog = console_to_drm_log(con);
+	int i;
+
+	if (!dlog->probed)
+		drm_log_init_client(dlog);
+
+	/* 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)
+{
+	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_dbg(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");
+}