diff options
Diffstat (limited to 'drivers/gpu/drm/drm_panic.c')
| -rw-r--r-- | drivers/gpu/drm/drm_panic.c | 988 |
1 files changed, 988 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c new file mode 100644 index 000000000000..b4de79583805 --- /dev/null +++ b/drivers/gpu/drm/drm_panic.c @@ -0,0 +1,988 @@ +// SPDX-License-Identifier: GPL-2.0 or MIT +/* + * Copyright (c) 2023 Red Hat. + * Author: Jocelyn Falempe <jfalempe@redhat.com> + * inspired by the drm_log driver from David Herrmann <dh.herrmann@gmail.com> + * Tux Ascii art taken from cowsay written by Tony Monroe + */ + +#include <linux/font.h> +#include <linux/highmem.h> +#include <linux/init.h> +#include <linux/iosys-map.h> +#include <linux/kdebug.h> +#include <linux/kmsg_dump.h> +#include <linux/linux_logo.h> +#include <linux/list.h> +#include <linux/math.h> +#include <linux/module.h> +#include <linux/overflow.h> +#include <linux/printk.h> +#include <linux/types.h> +#include <linux/utsname.h> +#include <linux/zlib.h> + +#include <drm/drm_drv.h> +#include <drm/drm_fourcc.h> +#include <drm/drm_framebuffer.h> +#include <drm/drm_modeset_helper_vtables.h> +#include <drm/drm_panic.h> +#include <drm/drm_plane.h> +#include <drm/drm_print.h> +#include <drm/drm_rect.h> + +#include "drm_crtc_internal.h" +#include "drm_draw_internal.h" + +MODULE_AUTHOR("Jocelyn Falempe"); +MODULE_DESCRIPTION("DRM panic handler"); +MODULE_LICENSE("GPL"); + +static char drm_panic_screen[16] = CONFIG_DRM_PANIC_SCREEN; +module_param_string(panic_screen, drm_panic_screen, sizeof(drm_panic_screen), 0644); +MODULE_PARM_DESC(panic_screen, + "Choose what will be displayed by drm_panic, 'user' or 'kmsg' [default=" + CONFIG_DRM_PANIC_SCREEN "]"); + +/** + * DOC: overview + * + * To enable DRM panic for a driver, the primary plane must implement a + * &drm_plane_helper_funcs.get_scanout_buffer helper function. It is then + * automatically registered to the drm panic handler. + * When a panic occurs, the &drm_plane_helper_funcs.get_scanout_buffer will be + * called, and the driver can provide a framebuffer so the panic handler can + * draw the panic screen on it. Currently only linear buffer and a few color + * formats are supported. + * Optionally the driver can also provide a &drm_plane_helper_funcs.panic_flush + * callback, that will be called after that, to send additional commands to the + * hardware to make the scanout buffer visible. + */ + +/* + * This module displays a user friendly message on screen when a kernel panic + * occurs. This is conflicting with fbcon, so you can only enable it when fbcon + * is disabled. + * It's intended for end-user, so have minimal technical/debug information. + * + * Implementation details: + * + * It is a panic handler, so it can't take lock, allocate memory, run tasks/irq, + * or attempt to sleep. It's a best effort, and it may not be able to display + * the message in all situations (like if the panic occurs in the middle of a + * modesetting). + * It will display only one static frame, so performance optimizations are low + * priority as the machine is already in an unusable state. + */ + +struct drm_panic_line { + u32 len; + const char *txt; +}; + +#define PANIC_LINE(s) {.len = sizeof(s) - 1, .txt = s} + +static struct drm_panic_line panic_msg[] = { + PANIC_LINE("KERNEL PANIC!"), + PANIC_LINE(""), + PANIC_LINE("Please reboot your computer."), + PANIC_LINE(""), + PANIC_LINE(""), /* will be replaced by the panic description */ +}; + +static const size_t panic_msg_lines = ARRAY_SIZE(panic_msg); + +static const struct drm_panic_line logo_ascii[] = { + PANIC_LINE(" .--. _"), + PANIC_LINE(" |o_o | | |"), + PANIC_LINE(" |:_/ | | |"), + PANIC_LINE(" // \\ \\ |_|"), + PANIC_LINE(" (| | ) _"), + PANIC_LINE(" /'\\_ _/`\\ (_)"), + PANIC_LINE(" \\___)=(___/"), +}; + +static const size_t logo_ascii_lines = ARRAY_SIZE(logo_ascii); + +#if defined(CONFIG_LOGO) && !defined(MODULE) +static const struct linux_logo *logo_mono; + +static int drm_panic_setup_logo(void) +{ + const struct linux_logo *logo = fb_find_logo(1); + const unsigned char *logo_data; + struct linux_logo *logo_dup; + + if (!logo || logo->type != LINUX_LOGO_MONO) + return 0; + + /* The logo is __init, so we must make a copy for later use */ + logo_data = kmemdup(logo->data, + size_mul(DIV_ROUND_UP(logo->width, BITS_PER_BYTE), logo->height), + GFP_KERNEL); + if (!logo_data) + return -ENOMEM; + + logo_dup = kmemdup(logo, sizeof(*logo), GFP_KERNEL); + if (!logo_dup) { + kfree(logo_data); + return -ENOMEM; + } + + logo_dup->data = logo_data; + logo_mono = logo_dup; + + return 0; +} + +device_initcall(drm_panic_setup_logo); +#else +#define logo_mono ((const struct linux_logo *)NULL) +#endif + +/* + * Blit & Fill functions + */ +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) +{ + unsigned int y, x; + + for (y = 0; y < drm_rect_height(clip); y++) + for (x = 0; x < drm_rect_width(clip); x++) + if (drm_draw_is_pixel_fg(sbuf8, spitch, x / scale, y / scale)) + sb->set_pixel(sb, clip->x1 + x, clip->y1 + y, fg_color); +} + +static void drm_panic_write_pixel16(void *vaddr, unsigned int offset, u16 color) +{ + u16 *p = vaddr + offset; + + *p = color; +} + +static void drm_panic_write_pixel24(void *vaddr, unsigned int offset, u32 color) +{ + u8 *p = vaddr + offset; + + *p++ = color & 0xff; + color >>= 8; + *p++ = color & 0xff; + color >>= 8; + *p = color & 0xff; +} + +static void drm_panic_write_pixel32(void *vaddr, unsigned int offset, u32 color) +{ + u32 *p = vaddr + offset; + + *p = color; +} + +static void drm_panic_write_pixel(void *vaddr, unsigned int offset, u32 color, unsigned int cpp) +{ + switch (cpp) { + case 2: + drm_panic_write_pixel16(vaddr, offset, color); + break; + case 3: + drm_panic_write_pixel24(vaddr, offset, color); + break; + case 4: + drm_panic_write_pixel32(vaddr, offset, color); + break; + default: + pr_debug_once("Can't blit with pixel width %d\n", cpp); + } +} + +/* + * The scanout buffer pages are not mapped, so for each pixel, + * use kmap_local_page_try_from_panic() to map the page, and write the pixel. + * Try to keep the map from the previous pixel, to avoid too much map/unmap. + */ +static void drm_panic_blit_page(struct page **pages, unsigned int dpitch, + unsigned int cpp, const u8 *sbuf8, + unsigned int spitch, struct drm_rect *clip, + unsigned int scale, u32 fg32) +{ + unsigned int y, x; + unsigned int page = ~0; + unsigned int height = drm_rect_height(clip); + unsigned int width = drm_rect_width(clip); + void *vaddr = NULL; + + for (y = 0; y < height; y++) { + for (x = 0; x < width; x++) { + if (drm_draw_is_pixel_fg(sbuf8, spitch, x / scale, y / scale)) { + unsigned int new_page; + unsigned int offset; + + offset = (y + clip->y1) * dpitch + (x + clip->x1) * cpp; + new_page = offset >> PAGE_SHIFT; + offset = offset % PAGE_SIZE; + if (new_page != page) { + if (!pages[new_page]) + continue; + if (vaddr) + kunmap_local(vaddr); + page = new_page; + vaddr = kmap_local_page_try_from_panic(pages[page]); + } + if (vaddr) + drm_panic_write_pixel(vaddr, offset, fg32, cpp); + } + } + } + if (vaddr) + kunmap_local(vaddr); +} + +/* + * drm_panic_blit - convert a monochrome image to a linear framebuffer + * @sb: destination scanout buffer + * @clip: destination rectangle + * @sbuf8: source buffer, in monochrome format, 8 pixels per byte. + * @spitch: source pitch in bytes + * @scale: integer scale, source buffer is scale time smaller than destination + * rectangle + * @fg_color: foreground color, in destination format + * + * This can be used to draw a font character, which is a monochrome image, to a + * framebuffer in other supported format. + */ +static void drm_panic_blit(struct drm_scanout_buffer *sb, struct drm_rect *clip, + const u8 *sbuf8, unsigned int spitch, + unsigned int scale, u32 fg_color) + +{ + struct iosys_map map; + + if (sb->set_pixel) + return drm_panic_blit_pixel(sb, clip, sbuf8, spitch, scale, fg_color); + + if (sb->pages) + return drm_panic_blit_page(sb->pages, sb->pitch[0], sb->format->cpp[0], + sbuf8, spitch, clip, scale, fg_color); + + map = sb->map[0]; + iosys_map_incr(&map, clip->y1 * sb->pitch[0] + clip->x1 * sb->format->cpp[0]); + + switch (sb->format->cpp[0]) { + case 2: + drm_draw_blit16(&map, sb->pitch[0], sbuf8, spitch, + drm_rect_height(clip), drm_rect_width(clip), scale, fg_color); + break; + case 3: + drm_draw_blit24(&map, sb->pitch[0], sbuf8, spitch, + drm_rect_height(clip), drm_rect_width(clip), scale, fg_color); + break; + case 4: + drm_draw_blit32(&map, sb->pitch[0], sbuf8, spitch, + drm_rect_height(clip), drm_rect_width(clip), scale, fg_color); + break; + default: + WARN_ONCE(1, "Can't blit with pixel width %d\n", sb->format->cpp[0]); + } +} + +static void drm_panic_fill_pixel(struct drm_scanout_buffer *sb, + struct drm_rect *clip, + u32 color) +{ + unsigned int y, x; + + for (y = 0; y < drm_rect_height(clip); y++) + for (x = 0; x < drm_rect_width(clip); x++) + sb->set_pixel(sb, clip->x1 + x, clip->y1 + y, color); +} + +static void drm_panic_fill_page(struct page **pages, unsigned int dpitch, + unsigned int cpp, struct drm_rect *clip, + u32 color) +{ + unsigned int y, x; + unsigned int page = ~0; + void *vaddr = NULL; + + for (y = clip->y1; y < clip->y2; y++) { + for (x = clip->x1; x < clip->x2; x++) { + unsigned int new_page; + unsigned int offset; + + offset = y * dpitch + x * cpp; + new_page = offset >> PAGE_SHIFT; + offset = offset % PAGE_SIZE; + if (new_page != page) { + if (vaddr) + kunmap_local(vaddr); + page = new_page; + vaddr = kmap_local_page_try_from_panic(pages[page]); + } + drm_panic_write_pixel(vaddr, offset, color, cpp); + } + } + if (vaddr) + kunmap_local(vaddr); +} + +/* + * drm_panic_fill - Fill a rectangle with a color + * @sb: destination scanout buffer + * @clip: destination rectangle + * @color: foreground color, in destination format + * + * Fill a rectangle with a color, in a linear framebuffer. + */ +static void drm_panic_fill(struct drm_scanout_buffer *sb, struct drm_rect *clip, + u32 color) +{ + struct iosys_map map; + + if (sb->set_pixel) + return drm_panic_fill_pixel(sb, clip, color); + + if (sb->pages) + return drm_panic_fill_page(sb->pages, sb->pitch[0], sb->format->cpp[0], + clip, color); + + map = sb->map[0]; + iosys_map_incr(&map, clip->y1 * sb->pitch[0] + clip->x1 * sb->format->cpp[0]); + + switch (sb->format->cpp[0]) { + case 2: + drm_draw_fill16(&map, sb->pitch[0], drm_rect_height(clip), + drm_rect_width(clip), color); + break; + case 3: + drm_draw_fill24(&map, sb->pitch[0], drm_rect_height(clip), + drm_rect_width(clip), color); + break; + case 4: + drm_draw_fill32(&map, sb->pitch[0], drm_rect_height(clip), + drm_rect_width(clip), color); + break; + default: + WARN_ONCE(1, "Can't fill with pixel width %d\n", sb->format->cpp[0]); + } +} + +static unsigned int get_max_line_len(const struct drm_panic_line *lines, int len) +{ + int i; + unsigned int max = 0; + + for (i = 0; i < len; i++) + max = max(lines[i].len, max); + return max; +} + +/* + * Draw a text in a rectangle on a framebuffer. The text is truncated if it overflows the rectangle + */ +static void draw_txt_rectangle(struct drm_scanout_buffer *sb, + const struct font_desc *font, + const struct drm_panic_line *msg, + unsigned int msg_lines, + bool centered, + struct drm_rect *clip, + u32 color) +{ + int i, j; + const u8 *src; + size_t font_pitch = DIV_ROUND_UP(font->width, 8); + struct drm_rect rec; + + msg_lines = min(msg_lines, drm_rect_height(clip) / font->height); + for (i = 0; i < msg_lines; i++) { + size_t line_len = min(msg[i].len, drm_rect_width(clip) / font->width); + + rec.y1 = clip->y1 + i * font->height; + rec.y2 = rec.y1 + font->height; + rec.x1 = clip->x1; + + if (centered) + rec.x1 += (drm_rect_width(clip) - (line_len * font->width)) / 2; + + for (j = 0; j < line_len; j++) { + 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; + } + } +} + +static void drm_panic_logo_rect(struct drm_rect *rect, const struct font_desc *font) +{ + if (logo_mono) { + drm_rect_init(rect, 0, 0, logo_mono->width, logo_mono->height); + } else { + int logo_width = get_max_line_len(logo_ascii, logo_ascii_lines) * font->width; + + drm_rect_init(rect, 0, 0, logo_width, logo_ascii_lines * font->height); + } +} + +static void drm_panic_logo_draw(struct drm_scanout_buffer *sb, struct drm_rect *rect, + const struct font_desc *font, u32 fg_color) +{ + if (logo_mono) + drm_panic_blit(sb, rect, logo_mono->data, + DIV_ROUND_UP(drm_rect_width(rect), 8), 1, fg_color); + else + draw_txt_rectangle(sb, font, logo_ascii, logo_ascii_lines, false, rect, + fg_color); +} + +static void draw_panic_static_user(struct drm_scanout_buffer *sb) +{ + 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; + + if (!font) + return; + + r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height); + drm_panic_logo_rect(&r_logo, font); + + msg_width = min(get_max_line_len(panic_msg, panic_msg_lines) * font->width, sb->width); + msg_height = min(panic_msg_lines * font->height, sb->height); + r_msg = DRM_RECT_INIT(0, 0, msg_width, msg_height); + + /* Center the panic message */ + drm_rect_translate(&r_msg, (sb->width - r_msg.x2) / 2, (sb->height - r_msg.y2) / 2); + + /* Fill with the background color, and draw text on top */ + drm_panic_fill(sb, &r_screen, bg_color); + + if (!drm_rect_overlap(&r_logo, &r_msg)) + drm_panic_logo_draw(sb, &r_logo, font, fg_color); + + draw_txt_rectangle(sb, font, panic_msg, panic_msg_lines, true, &r_msg, fg_color); +} + +/* + * Draw one line of kmsg, and handle wrapping if it won't fit in the screen width. + * Return the y-offset of the next line. + */ +static int draw_line_with_wrap(struct drm_scanout_buffer *sb, const struct font_desc *font, + struct drm_panic_line *line, int yoffset, u32 fg_color) +{ + int chars_per_row = sb->width / font->width; + struct drm_rect r_txt = DRM_RECT_INIT(0, yoffset, sb->width, sb->height); + struct drm_panic_line line_wrap; + + if (line->len > chars_per_row) { + line_wrap.len = line->len % chars_per_row; + line_wrap.txt = line->txt + line->len - line_wrap.len; + draw_txt_rectangle(sb, font, &line_wrap, 1, false, &r_txt, fg_color); + r_txt.y1 -= font->height; + if (r_txt.y1 < 0) + return r_txt.y1; + while (line_wrap.txt > line->txt) { + line_wrap.txt -= chars_per_row; + line_wrap.len = chars_per_row; + draw_txt_rectangle(sb, font, &line_wrap, 1, false, &r_txt, fg_color); + r_txt.y1 -= font->height; + if (r_txt.y1 < 0) + return r_txt.y1; + } + } else { + draw_txt_rectangle(sb, font, line, 1, false, &r_txt, fg_color); + r_txt.y1 -= font->height; + } + return r_txt.y1; +} + +/* + * Draw the kmsg buffer to the screen, starting from the youngest message at the bottom, + * and going up until reaching the top of the screen. + */ +static void draw_panic_static_kmsg(struct drm_scanout_buffer *sb) +{ + 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; + char kmsg_buf[512]; + size_t kmsg_len; + struct drm_panic_line line; + int yoffset; + + if (!font) + return; + + yoffset = sb->height - font->height - (sb->height % font->height) / 2; + + /* Fill with the background color, and draw text on top */ + drm_panic_fill(sb, &r_screen, bg_color); + + kmsg_dump_rewind(&iter); + while (kmsg_dump_get_buffer(&iter, false, kmsg_buf, sizeof(kmsg_buf), &kmsg_len)) { + char *start; + char *end; + + /* ignore terminating NUL and newline */ + start = kmsg_buf + kmsg_len - 2; + end = kmsg_buf + kmsg_len - 1; + while (start > kmsg_buf && yoffset >= 0) { + while (start > kmsg_buf && *start != '\n') + start--; + /* don't count the newline character */ + line.txt = start + (start == kmsg_buf ? 0 : 1); + line.len = end - line.txt; + + yoffset = draw_line_with_wrap(sb, font, &line, yoffset, fg_color); + end = start; + start--; + } + } +} + +#if defined(CONFIG_DRM_PANIC_SCREEN_QR_CODE) +/* + * It is unwise to allocate memory in the panic callback, so the buffers are + * pre-allocated. Only 2 buffers and the zlib workspace are needed. + * Two buffers are enough, using the following buffer usage: + * 1) kmsg messages are dumped in buffer1 + * 2) kmsg is zlib-compressed into buffer2 + * 3) compressed kmsg is encoded as QR-code Numeric stream in buffer1 + * 4) QR-code image is generated in buffer2 + * The Max QR code size is V40, 177x177, 4071 bytes for image, 2956 bytes for + * data segments. + * + * Typically, ~7500 bytes of kmsg, are compressed into 2800 bytes, which fits in + * a V40 QR-code (177x177). + * + * If CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL is not set, the kmsg data will be put + * directly in the QR code. + * 1) kmsg messages are dumped in buffer1 + * 2) kmsg message is encoded as byte stream in buffer2 + * 3) QR-code image is generated in buffer1 + */ + +static uint panic_qr_version = CONFIG_DRM_PANIC_SCREEN_QR_VERSION; +module_param(panic_qr_version, uint, 0644); +MODULE_PARM_DESC(panic_qr_version, "maximum version (size) of the QR code"); + +#define MAX_QR_DATA 2956 +#define MAX_ZLIB_RATIO 3 +#define QR_BUFFER1_SIZE (MAX_ZLIB_RATIO * MAX_QR_DATA) /* Must also be > 4071 */ +#define QR_BUFFER2_SIZE 4096 +#define QR_MARGIN 4 /* 4 modules of foreground color around the qr code */ + +/* Compression parameters */ +#define COMPR_LEVEL 6 +#define WINDOW_BITS 12 +#define MEM_LEVEL 4 + +static char *qrbuf1; +static char *qrbuf2; +static struct z_stream_s stream; + +static void __init drm_panic_qr_init(void) +{ + qrbuf1 = kmalloc(QR_BUFFER1_SIZE, GFP_KERNEL); + qrbuf2 = kmalloc(QR_BUFFER2_SIZE, GFP_KERNEL); + stream.workspace = kmalloc(zlib_deflate_workspacesize(WINDOW_BITS, MEM_LEVEL), + GFP_KERNEL); +} + +static void drm_panic_qr_exit(void) +{ + kfree(qrbuf1); + qrbuf1 = NULL; + kfree(qrbuf2); + qrbuf2 = NULL; + kfree(stream.workspace); + stream.workspace = NULL; +} + +static int drm_panic_get_qr_code_url(u8 **qr_image) +{ + struct kmsg_dump_iter iter; + char url[256]; + size_t kmsg_len, max_kmsg_size; + char *kmsg; + int max_qr_data_size, url_len; + + url_len = snprintf(url, sizeof(url), CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL "?a=%s&v=%s&z=", + utsname()->machine, utsname()->release); + + max_qr_data_size = drm_panic_qr_max_data_size(panic_qr_version, url_len); + max_kmsg_size = min(MAX_ZLIB_RATIO * max_qr_data_size, QR_BUFFER1_SIZE); + + /* get kmsg to buffer 1 */ + kmsg_dump_rewind(&iter); + kmsg_dump_get_buffer(&iter, false, qrbuf1, max_kmsg_size, &kmsg_len); + + if (!kmsg_len) + return -ENODATA; + kmsg = qrbuf1; + +try_again: + if (zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS, + MEM_LEVEL, Z_DEFAULT_STRATEGY) != Z_OK) + return -EINVAL; + + stream.next_in = kmsg; + stream.avail_in = kmsg_len; + stream.total_in = 0; + stream.next_out = qrbuf2; + stream.avail_out = QR_BUFFER2_SIZE; + stream.total_out = 0; + + if (zlib_deflate(&stream, Z_FINISH) != Z_STREAM_END) + return -EINVAL; + + if (zlib_deflateEnd(&stream) != Z_OK) + return -EINVAL; + + if (stream.total_out > max_qr_data_size) { + /* too much data for the QR code, so skip the first line and try again */ + kmsg = strchr(kmsg, '\n'); + if (!kmsg) + return -EINVAL; + /* skip the first \n */ + kmsg += 1; + kmsg_len = strlen(kmsg); + goto try_again; + } + *qr_image = qrbuf2; + + /* generate qr code image in buffer2 */ + return drm_panic_qr_generate(url, qrbuf2, stream.total_out, QR_BUFFER2_SIZE, + qrbuf1, QR_BUFFER1_SIZE); +} + +static int drm_panic_get_qr_code_raw(u8 **qr_image) +{ + struct kmsg_dump_iter iter; + size_t kmsg_len; + size_t max_kmsg_size = min(drm_panic_qr_max_data_size(panic_qr_version, 0), + QR_BUFFER1_SIZE); + + kmsg_dump_rewind(&iter); + kmsg_dump_get_buffer(&iter, false, qrbuf1, max_kmsg_size, &kmsg_len); + if (!kmsg_len) + return -ENODATA; + + *qr_image = qrbuf1; + return drm_panic_qr_generate(NULL, qrbuf1, kmsg_len, QR_BUFFER1_SIZE, + qrbuf2, QR_BUFFER2_SIZE); +} + +static int drm_panic_get_qr_code(u8 **qr_image) +{ + if (strlen(CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL) > 0) + return drm_panic_get_qr_code_url(qr_image); + else + return drm_panic_get_qr_code_raw(qr_image); +} + +/* + * Draw the panic message at the center of the screen, with a QR Code + */ +static int _draw_panic_static_qr_code(struct drm_scanout_buffer *sb) +{ + 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; + unsigned int msg_width, msg_height; + int qr_width, qr_canvas_width, qr_pitch, v_margin; + u8 *qr_image; + + if (!font || !qrbuf1 || !qrbuf2 || !stream.workspace) + return -ENOMEM; + + r_screen = DRM_RECT_INIT(0, 0, sb->width, sb->height); + + drm_panic_logo_rect(&r_logo, font); + + msg_width = min(get_max_line_len(panic_msg, panic_msg_lines) * font->width, sb->width); + msg_height = min(panic_msg_lines * font->height, sb->height); + r_msg = DRM_RECT_INIT(0, 0, msg_width, msg_height); + + max_qr_size = min(3 * sb->width / 4, 3 * sb->height / 4); + + qr_width = drm_panic_get_qr_code(&qr_image); + if (qr_width <= 0) + return -ENOSPC; + + qr_canvas_width = qr_width + QR_MARGIN * 2; + scale = max_qr_size / qr_canvas_width; + /* QR code is not readable if not scaled at least by 2 */ + if (scale < 2) + return -ENOSPC; + + pr_debug("QR width %d and scale %d\n", qr_width, scale); + r_qr_canvas = DRM_RECT_INIT(0, 0, qr_canvas_width * scale, qr_canvas_width * scale); + + v_margin = (sb->height - drm_rect_height(&r_qr_canvas) - drm_rect_height(&r_msg)) / 5; + + drm_rect_translate(&r_qr_canvas, (sb->width - r_qr_canvas.x2) / 2, 2 * v_margin); + r_qr = DRM_RECT_INIT(r_qr_canvas.x1 + QR_MARGIN * scale, r_qr_canvas.y1 + QR_MARGIN * scale, + qr_width * scale, qr_width * scale); + + /* Center the panic message */ + drm_rect_translate(&r_msg, (sb->width - r_msg.x2) / 2, + 3 * v_margin + drm_rect_height(&r_qr_canvas)); + + /* Fill with the background color, and draw text on top */ + drm_panic_fill(sb, &r_screen, bg_color); + + if (!drm_rect_overlap(&r_logo, &r_msg) && !drm_rect_overlap(&r_logo, &r_qr)) + drm_panic_logo_draw(sb, &r_logo, font, fg_color); + + draw_txt_rectangle(sb, font, panic_msg, panic_msg_lines, true, &r_msg, fg_color); + + /* Draw the qr code */ + qr_pitch = DIV_ROUND_UP(qr_width, 8); + drm_panic_fill(sb, &r_qr_canvas, fg_color); + drm_panic_fill(sb, &r_qr, bg_color); + drm_panic_blit(sb, &r_qr, qr_image, qr_pitch, scale, fg_color); + return 0; +} + +static void draw_panic_static_qr_code(struct drm_scanout_buffer *sb) +{ + if (_draw_panic_static_qr_code(sb)) + draw_panic_static_user(sb); +} +#else +static void draw_panic_static_qr_code(struct drm_scanout_buffer *sb) +{ + draw_panic_static_user(sb); +} + +static void drm_panic_qr_init(void) {}; +static void drm_panic_qr_exit(void) {}; +#endif + +/* + * drm_panic_is_format_supported() + * @format: a fourcc color code + * Returns: true if supported, false otherwise. + * + * Check if drm_panic will be able to use this color format. + */ +static bool drm_panic_is_format_supported(const struct drm_format_info *format) +{ + if (format->num_planes != 1) + return false; + return drm_draw_color_from_xrgb8888(0xffffff, format->format) != 0; +} + +static void draw_panic_dispatch(struct drm_scanout_buffer *sb) +{ + if (!strcmp(drm_panic_screen, "kmsg")) { + draw_panic_static_kmsg(sb); + } else if (!strcmp(drm_panic_screen, "qr_code")) { + draw_panic_static_qr_code(sb); + } else { + draw_panic_static_user(sb); + } +} + +static void drm_panic_set_description(const char *description) +{ + u32 len; + + if (description) { + struct drm_panic_line *desc_line = &panic_msg[panic_msg_lines - 1]; + + desc_line->txt = description; + len = strlen(description); + /* ignore the last newline character */ + if (len && description[len - 1] == '\n') + len -= 1; + desc_line->len = len; + } +} + +static void drm_panic_clear_description(void) +{ + struct drm_panic_line *desc_line = &panic_msg[panic_msg_lines - 1]; + + desc_line->len = 0; + desc_line->txt = NULL; +} + +static void draw_panic_plane(struct drm_plane *plane, const char *description) +{ + struct drm_scanout_buffer sb = { }; + int ret; + unsigned long flags; + + if (!drm_panic_trylock(plane->dev, flags)) + return; + + ret = plane->helper_private->get_scanout_buffer(plane, &sb); + + if (ret || !drm_panic_is_format_supported(sb.format)) + goto unlock; + + /* One of these should be set, or it can't draw pixels */ + if (!sb.set_pixel && !sb.pages && iosys_map_is_null(&sb.map[0])) + goto unlock; + + drm_panic_set_description(description); + + draw_panic_dispatch(&sb); + if (plane->helper_private->panic_flush) + plane->helper_private->panic_flush(plane); + + drm_panic_clear_description(); + +unlock: + drm_panic_unlock(plane->dev, flags); +} + +static struct drm_plane *to_drm_plane(struct kmsg_dumper *kd) +{ + return container_of(kd, struct drm_plane, kmsg_panic); +} + +static void drm_panic(struct kmsg_dumper *dumper, struct kmsg_dump_detail *detail) +{ + struct drm_plane *plane = to_drm_plane(dumper); + + if (detail->reason == KMSG_DUMP_PANIC) + draw_panic_plane(plane, detail->description); +} + + +/* + * DEBUG FS, This is currently unsafe. + * Create one file per plane, so it's possible to debug one plane at a time. + * TODO: It would be better to emulate an NMI context. + */ +#ifdef CONFIG_DRM_PANIC_DEBUG +#include <linux/debugfs.h> + +static ssize_t debugfs_trigger_write(struct file *file, const char __user *user_buf, + size_t count, loff_t *ppos) +{ + bool run; + + if (kstrtobool_from_user(user_buf, count, &run) == 0 && run) { + struct drm_plane *plane = file->private_data; + + draw_panic_plane(plane, "Test from debugfs"); + } + return count; +} + +static const struct file_operations dbg_drm_panic_ops = { + .owner = THIS_MODULE, + .write = debugfs_trigger_write, + .open = simple_open, +}; + +static void debugfs_register_plane(struct drm_plane *plane, int index) +{ + char fname[32]; + + snprintf(fname, 32, "drm_panic_plane_%d", index); + debugfs_create_file(fname, 0200, plane->dev->debugfs_root, + plane, &dbg_drm_panic_ops); +} +#else +static void debugfs_register_plane(struct drm_plane *plane, int index) {} +#endif /* CONFIG_DRM_PANIC_DEBUG */ + +/** + * drm_panic_is_enabled + * @dev: the drm device that may supports drm_panic + * + * returns true if the drm device supports drm_panic + */ +bool drm_panic_is_enabled(struct drm_device *dev) +{ + struct drm_plane *plane; + + if (!dev->mode_config.num_total_plane) + return false; + + drm_for_each_plane(plane, dev) + if (plane->helper_private && plane->helper_private->get_scanout_buffer) + return true; + return false; +} +EXPORT_SYMBOL(drm_panic_is_enabled); + +/** + * drm_panic_register() - Initialize DRM panic for a device + * @dev: the drm device on which the panic screen will be displayed. + */ +void drm_panic_register(struct drm_device *dev) +{ + struct drm_plane *plane; + int registered_plane = 0; + + if (!dev->mode_config.num_total_plane) + return; + + drm_for_each_plane(plane, dev) { + if (!plane->helper_private || !plane->helper_private->get_scanout_buffer) + continue; + plane->kmsg_panic.dump = drm_panic; + plane->kmsg_panic.max_reason = KMSG_DUMP_PANIC; + if (kmsg_dump_register(&plane->kmsg_panic)) + drm_warn(dev, "Failed to register panic handler\n"); + else { + debugfs_register_plane(plane, registered_plane); + registered_plane++; + } + } + if (registered_plane) + drm_info(dev, "Registered %d planes with drm panic\n", registered_plane); +} + +/** + * drm_panic_unregister() + * @dev: the drm device previously registered. + */ +void drm_panic_unregister(struct drm_device *dev) +{ + struct drm_plane *plane; + + if (!dev->mode_config.num_total_plane) + return; + + drm_for_each_plane(plane, dev) { + if (!plane->helper_private || !plane->helper_private->get_scanout_buffer) + continue; + kmsg_dump_unregister(&plane->kmsg_panic); + } +} + +/** + * drm_panic_init() - initialize DRM panic. + */ +void __init drm_panic_init(void) +{ + drm_panic_qr_init(); +} + +/** + * drm_panic_exit() - Free the resources taken by drm_panic_exit() + */ +void drm_panic_exit(void) +{ + drm_panic_qr_exit(); +} |