From patchwork Wed Sep 27 17:22:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jocelyn Falempe X-Patchwork-Id: 13401439 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D0026E82CB9 for ; Wed, 27 Sep 2023 17:29:15 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1C90810E585; Wed, 27 Sep 2023 17:29:15 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by gabe.freedesktop.org (Postfix) with ESMTPS id 135EC10E585 for ; Wed, 27 Sep 2023 17:29:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1695835750; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=oTC6QL6+BIjqbP4GtR6Y5NjUIhymL7cWT/rIpHoX3sM=; b=cFN/dB5ZZvQzqdcTO1+/81Ad1BqrP69+WeiiPazvH/4TSIU4Z5duTR7XMAW4YP0kEdp3eO hn4OTfLvC5tfnKUeo8wZWfg/8XXbCYMqqjZHUyttBMQpujw8YLXdd7BQ5RuYeOgwlS5l1Y VNltzJj3ohlJZpX4Hwdik9bj3DgVMuI= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-164-vVzOSImmN6eFmcPVvyECEQ-1; Wed, 27 Sep 2023 13:29:06 -0400 X-MC-Unique: vVzOSImmN6eFmcPVvyECEQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 494A7280D589; Wed, 27 Sep 2023 17:29:06 +0000 (UTC) Received: from hydra.redhat.com (unknown [10.39.195.27]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9FE94C15BB8; Wed, 27 Sep 2023 17:29:04 +0000 (UTC) From: Jocelyn Falempe To: dri-devel@lists.freedesktop.org, tzimmermann@suse.de, airlied@redhat.com, maarten.lankhorst@linux.intel.com, mripard@kernel.org, daniel@ffwll.ch, javierm@redhat.com, bluescreen_avenger@verizon.net Subject: [PATCH v3 2/3] drm/panic: Add a drm panic handler Date: Wed, 27 Sep 2023 19:22:51 +0200 Message-ID: <20230927172849.193996-3-jfalempe@redhat.com> In-Reply-To: <20230927172849.193996-1-jfalempe@redhat.com> References: <20230927172849.193996-1-jfalempe@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: gpiccoli@igalia.com, Jocelyn Falempe Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" This module displays a user friendly message when a kernel panic occurs. It currently doesn't contain any debug information, but that can be added later. v2 * Use get_scanout_buffer() instead of the drm client API. (Thomas Zimmermann) * Add the panic reason to the panic message (Nerdopolis) * Add an exclamation mark (Nerdopolis) v3 * Rework the drawing functions, to write the pixels line by line and to use the drm conversion helper to support other formats. (Thomas Zimmermann) Signed-off-by: Jocelyn Falempe --- drivers/gpu/drm/Kconfig | 11 ++ drivers/gpu/drm/Makefile | 1 + drivers/gpu/drm/drm_drv.c | 3 + drivers/gpu/drm/drm_panic.c | 366 ++++++++++++++++++++++++++++++++++++ include/drm/drm_drv.h | 14 ++ include/drm/drm_panic.h | 41 ++++ 6 files changed, 436 insertions(+) create mode 100644 drivers/gpu/drm/drm_panic.c create mode 100644 include/drm/drm_panic.h diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index afb3b2f5f425..98d78f865180 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -99,6 +99,17 @@ config DRM_KMS_HELPER help CRTC helpers for KMS drivers. +config DRM_PANIC + bool "Display a user-friendly message when a kernel panic occurs" + depends on DRM && !FRAMEBUFFER_CONSOLE + select FONT_SUPPORT + default y if DRM_SIMPLEDRM + 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 + console instead of fbcon. + It will only work if your graphic driver supports this feature. + config DRM_DEBUG_DP_MST_TOPOLOGY_REFS bool "Enable refcount backtrace history in the DP MST helpers" depends on STACKTRACE_SUPPORT diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 7a09a89b493b..a525dd9a2751 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -72,6 +72,7 @@ drm-$(CONFIG_DRM_PRIVACY_SCREEN) += \ drm_privacy_screen_x86.o drm-$(CONFIG_DRM_ACCEL) += ../../accel/drm_accel.o obj-$(CONFIG_DRM) += drm.o +drm-$(CONFIG_DRM_PANIC) += drm_panic.o obj-$(CONFIG_DRM_PANEL_ORIENTATION_QUIRKS) += drm_panel_orientation_quirks.o diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 12687dd9e1ac..0e0f1e258845 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -45,6 +45,7 @@ #include #include #include +#include #include "drm_crtc_internal.h" #include "drm_internal.h" @@ -1067,6 +1068,7 @@ static void drm_core_exit(void) unregister_chrdev(DRM_MAJOR, "drm"); debugfs_remove(drm_debugfs_root); drm_sysfs_destroy(); + drm_panic_exit(); idr_destroy(&drm_minors_idr); drm_connector_ida_destroy(); } @@ -1078,6 +1080,7 @@ static int __init drm_core_init(void) drm_connector_ida_init(); idr_init(&drm_minors_idr); drm_memcpy_init_early(); + drm_panic_init(); ret = drm_sysfs_init(); if (ret < 0) { diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c new file mode 100644 index 000000000000..1d93e4dbed9a --- /dev/null +++ b/drivers/gpu/drm/drm_panic.c @@ -0,0 +1,366 @@ +// SPDX-License-Identifier: GPL-2.0 or MIT +/* + * Copyright (c) 2023 Jocelyn Falempe + * inspired by the drm_log driver from David Herrmann + * Tux Ascii art taken from cowsay written by Tony Monroe + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include + + +MODULE_AUTHOR("Jocelyn Falempe"); +MODULE_DESCRIPTION("DRM PANIC"); +MODULE_LICENSE("GPL"); + +/** + * DOC: DRM Panic + * + * This module displays a user friendly message on screen when a kernel panic + * occurs. It's useful when using a user-space console instead of fbcon. + * It's intended for end-user, so have minimal technical/debug information. + * + * It will display only one static frame, so performance optimizations are low + * priority as the machine is already in an unusable state. + */ + +/* + * List of active drm devices that can render a panic + */ +struct dpanic_drm_device { + struct list_head head; + struct drm_device *dev; +}; + +struct dpanic_line { + u32 len; + const char *txt; +}; + +#define PANIC_LINE(s) {.len = sizeof(s) - 1, .txt = s} + +struct dpanic_line panic_msg[] = { + PANIC_LINE("KERNEL PANIC !"), + PANIC_LINE(""), + PANIC_LINE("Please reboot your computer."), + PANIC_LINE(""), + PANIC_LINE(""), /* overwritten with panic reason */ +}; + +const struct dpanic_line logo[] = { + PANIC_LINE(" .--. _"), + PANIC_LINE(" |o_o | | |"), + PANIC_LINE(" |:_/ | | |"), + PANIC_LINE(" // \\ \\ |_|"), + PANIC_LINE(" (| | ) _"), + PANIC_LINE(" /'\\_ _/`\\ (_)"), + PANIC_LINE(" \\___)=(___/"), +}; + +static LIST_HEAD(dpanic_devices); +static DEFINE_MUTEX(dpanic_lock); + +/* + * This buffer is used to convert xrgb8888 to the scanout buffer format. + * It is allocated when the first client register, and freed when the last client + * unregisters. + * There is no need for mutex, as the panic garantee that only 1 CPU is still + * running, and preemption is disabled. + */ +#define DRM_PANIC_MAX_WIDTH 8096 +static u32 *dpanic_line_buf; +static u32 fg_color = le32_to_cpu(0x00ffffff); +static u32 bg_color = le32_to_cpu(0x00000000); + +static void dpanic_draw_line(const struct dpanic_line *msg, size_t left_margin, + size_t l, size_t width, const struct font_desc *font) +{ + size_t x, i, j; + const u8 *src; + size_t src_stride = DIV_ROUND_UP(font->width, 8); + u32 *dst = dpanic_line_buf; + + for (x = 0; x < left_margin * font->width; x++) + *dst++ = bg_color; + + for (i = 0; i < msg->len; i++) { + for (j = 0; j < font->width; j++) { + src = font->data + (msg->txt[i] * font->height + l) * src_stride; + *dst++ = (src[j / 8] & (0x80 >> (j % 8))) ? fg_color : bg_color; + } + } + for (x = (left_margin + msg->len) * font->width; x < width ; x++) + *dst++ = bg_color; +} + +static void dpanic_draw_txt_line(const struct dpanic_line *msg, size_t left_margin, size_t y, + struct drm_scanout_buffer *sb, + const struct font_desc *font, + void (*convert)(void *dbuf, const void *sbuf, unsigned int npixels)) +{ + size_t dst_off; + size_t l; + + for (l = 0; l < font->height; l++) { + dpanic_draw_line(msg, left_margin, l, sb->width, font); + if (convert) + convert(dpanic_line_buf, dpanic_line_buf, sb->width); + + dst_off = (y * font->height + l) * sb->pitch; + iosys_map_memcpy_to(&sb->map, dst_off, dpanic_line_buf, + sb->width * sb->format->cpp[0]); + } +} + +static void dpanic_draw_empty_txt_line(size_t y, + struct drm_scanout_buffer *sb, + const struct font_desc *font, + void (*convert)(void *dbuf, const void *sbuf, unsigned int npixels)) +{ + size_t i, dst_off; + u32 *dst = dpanic_line_buf; + + for (i = 0; i < sb->width; i++) + *dst++ = bg_color; + + if (convert) + convert(dpanic_line_buf, dpanic_line_buf, sb->width); + + for (i = 0; i < font->height; i++) { + dst_off = (y * font->height + i) * sb->pitch; + iosys_map_memcpy_to(&sb->map, dst_off, dpanic_line_buf, + sb->width * sb->format->cpp[0]); + } +} + +static size_t dpanic_needed_lines(size_t chars_per_line) +{ + size_t msg_len = ARRAY_SIZE(panic_msg); + size_t lines = 0; + size_t i; + + for (i = 0; i < msg_len; i++) + lines += panic_msg[i].len ? DIV_ROUND_UP(panic_msg[i].len, chars_per_line) : 1; + return lines; +} + +static bool dpanic_can_draw_logo(size_t chars_per_line, size_t lines, size_t msg_lines) +{ + size_t i; + + for (i = 0; i < ARRAY_SIZE(logo); i++) { + if (logo[i].len > chars_per_line) + return false; + } + if (lines < msg_lines + ARRAY_SIZE(logo)) + return false; + return true; +} + +static size_t get_start_line(size_t lines, size_t msg_lines, bool can_draw_logo) +{ + size_t remaining; + size_t logo_len = ARRAY_SIZE(logo); + + if (lines < msg_lines) + return 0; + remaining = lines - msg_lines; + if (can_draw_logo && remaining / 2 <= logo_len) + return logo_len + (remaining - logo_len) / 4; + return remaining / 2; +} + +/* + * Return the function to convert xrgb8888 to the scanout buffer format + * NULL if no conversion is needed, and ERR_PTR if format can't be converted + */ +static void (*get_convert_func(const struct drm_format_info *format)) + (void *, const void *, unsigned int) +{ + switch (format->format) { + case DRM_FORMAT_XRGB8888: + return NULL; + case DRM_FORMAT_RGB565: + return drm_fb_xrgb8888_to_rgb565_line; + default: + return ERR_PTR(EINVAL); + } +} + + +/* + * Draw the panic message at the center of the screen + */ +static void dpanic_static_draw(struct drm_scanout_buffer *sb, const char *msg) +{ + size_t lines, msg_lines, l, msg_start_line, msgi; + size_t center, chars_per_line; + bool can_draw_logo; + struct dpanic_line panic_line; + size_t msg_len = ARRAY_SIZE(panic_msg); + size_t logo_len = ARRAY_SIZE(logo); + void (*convert)(void *dbuf, const void *sbuf, unsigned int npixels); + const struct font_desc *font = get_default_font(sb->width, sb->height, 0x8080, 0x8080); + + if (!font) + return; + + /* Set the panic reason */ + panic_msg[msg_len - 1].len = strlen(msg); + panic_msg[msg_len - 1].txt = msg; + + lines = sb->height / font->height; + chars_per_line = sb->width / font->width; + + msg_lines = dpanic_needed_lines(chars_per_line); + can_draw_logo = dpanic_can_draw_logo(chars_per_line, lines, msg_lines); + msg_start_line = get_start_line(lines, msg_lines, can_draw_logo); + + convert = get_convert_func(sb->format); + if (IS_ERR(convert)) + return; + + msgi = 0; + panic_line.len = 0; + for (l = 0; l < lines; l++) { + if (can_draw_logo && l < logo_len) + dpanic_draw_txt_line(&logo[l], 0, l, sb, font, convert); + else if (l >= msg_start_line && msgi < msg_len) { + if (!panic_line.len) { + panic_line.txt = panic_msg[msgi].txt; + panic_line.len = panic_msg[msgi].len; + } + if (!panic_line.len) + dpanic_draw_empty_txt_line(l, sb, font, convert); + else { + center = panic_line.len > chars_per_line ? + 0 : (chars_per_line - panic_line.len) / 2; + dpanic_draw_txt_line(&panic_line, center, l, sb, font, convert); + } + if (panic_line.len > chars_per_line) { + panic_line.len -= chars_per_line; + panic_line.txt += chars_per_line; + } else { + panic_line.len = 0; + msgi++; + } + } else { + dpanic_draw_empty_txt_line(l, sb, font, convert); + } + } +} + +static void drm_panic_device(struct drm_device *dev, const char *msg) +{ + struct drm_scanout_buffer sb; + + if (dev->driver->get_scanout_buffer(dev, &sb)) + return; + if (!dpanic_line_buf) + return; + + /* to avoid buffer overflow on dpanic_line_buf */ + if (sb.width > DRM_PANIC_MAX_WIDTH) + sb.width = DRM_PANIC_MAX_WIDTH; + + dpanic_static_draw(&sb, msg); +} + +static int drm_panic(struct notifier_block *this, unsigned long event, + void *ptr) +{ + struct dpanic_drm_device *dpanic_device; + + list_for_each_entry(dpanic_device, &dpanic_devices, head) { + drm_panic_device(dpanic_device->dev, ptr); + } + return NOTIFY_OK; +} + +struct notifier_block drm_panic_notifier = { + .notifier_call = drm_panic, +}; + +/** + * 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 dpanic_drm_device *new; + + new = kzalloc(sizeof(*new), GFP_KERNEL); + if (!new) + return; + + new->dev = dev; + mutex_lock(&dpanic_lock); + if (!dpanic_line_buf) + dpanic_line_buf = kmalloc(DRM_PANIC_MAX_WIDTH * sizeof(u32), GFP_KERNEL); + if (!dpanic_line_buf) + goto unlock; + list_add_tail(&new->head, &dpanic_devices); + drm_info(dev, "Registered with drm panic\n"); +unlock: + mutex_unlock(&dpanic_lock); +} +EXPORT_SYMBOL(drm_panic_register); + +/** + * drm_panic_unregister() + * @dev: the DRM device previously registered. + */ +void drm_panic_unregister(struct drm_device *dev) +{ + struct dpanic_drm_device *dpanic_device; + struct dpanic_drm_device *found = NULL; + + mutex_lock(&dpanic_lock); + list_for_each_entry(dpanic_device, &dpanic_devices, head) { + if (dpanic_device->dev == dev) + found = dpanic_device; + } + if (found) { + list_del(&found->head); + kfree(found); + drm_info(dev, "Unregistered with drm panic\n"); + } + if (dpanic_line_buf && list_empty(&dpanic_devices)) { + kfree(dpanic_line_buf); + dpanic_line_buf = NULL; + } + mutex_unlock(&dpanic_lock); +} +EXPORT_SYMBOL(drm_panic_unregister); + +/** + * drm_panic_init() - Initialize drm-panic subsystem + * + * register the panic notifier + */ +void drm_panic_init(void) +{ + atomic_notifier_chain_register(&panic_notifier_list, + &drm_panic_notifier); +} + +/** + * drm_log_exit() - Shutdown drm-panic subsystem + */ +void drm_panic_exit(void) +{ + atomic_notifier_chain_unregister(&panic_notifier_list, + &drm_panic_notifier); +} diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h index 89e2706cac56..e538c87116d3 100644 --- a/include/drm/drm_drv.h +++ b/include/drm/drm_drv.h @@ -43,6 +43,7 @@ struct dma_buf_attachment; struct drm_display_mode; struct drm_mode_create_dumb; struct drm_printer; +struct drm_scanout_buffer; struct sg_table; /** @@ -408,6 +409,19 @@ struct drm_driver { */ void (*show_fdinfo)(struct drm_printer *p, struct drm_file *f); + /** + * @get_scanout_buffer: + * + * Get the current scanout buffer, to display a panic message with drm_panic. + * It is called from a panic callback, and must follow its restrictions. + * + * Returns: + * + * Zero on success, negative errno on failure. + */ + int (*get_scanout_buffer)(struct drm_device *dev, + struct drm_scanout_buffer *sb); + /** @major: driver major number */ int major; /** @minor: driver minor number */ diff --git a/include/drm/drm_panic.h b/include/drm/drm_panic.h new file mode 100644 index 000000000000..db430b8dfbb2 --- /dev/null +++ b/include/drm/drm_panic.h @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0 or MIT */ +#ifndef __DRM_PANIC_H__ +#define __DRM_PANIC_H__ + +/* + * Copyright (c) 2023 Jocelyn Falempe + */ + +#include +#include +#include + +struct drm_device; + +struct drm_scanout_buffer { + const struct drm_format_info *format; + struct iosys_map map; + unsigned int pitch; + unsigned int width; + unsigned int height; +}; + +#ifdef CONFIG_DRM_PANIC + +void drm_panic_init(void); +void drm_panic_exit(void); + +void drm_panic_register(struct drm_device *dev); +void drm_panic_unregister(struct drm_device *dev); + +#else + +static inline void drm_panic_init(void) {} +static inline void drm_panic_exit(void) {} + +static inline void drm_panic_register(struct drm_device *dev) {} +static inline void drm_panic_unregister(struct drm_device *dev) {} + +#endif + +#endif /* __DRM_LOG_H__ */