From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- drivers/gpu/drm/stm/Kconfig | 35 + drivers/gpu/drm/stm/Makefile | 10 + drivers/gpu/drm/stm/drv.c | 273 +++++ drivers/gpu/drm/stm/dw_mipi_dsi-stm.c | 800 +++++++++++++ drivers/gpu/drm/stm/ltdc.c | 2116 +++++++++++++++++++++++++++++++++ drivers/gpu/drm/stm/ltdc.h | 71 ++ drivers/gpu/drm/stm/lvds.c | 1228 +++++++++++++++++++ 7 files changed, 4533 insertions(+) create mode 100644 drivers/gpu/drm/stm/Kconfig create mode 100644 drivers/gpu/drm/stm/Makefile create mode 100644 drivers/gpu/drm/stm/drv.c create mode 100644 drivers/gpu/drm/stm/dw_mipi_dsi-stm.c create mode 100644 drivers/gpu/drm/stm/ltdc.c create mode 100644 drivers/gpu/drm/stm/ltdc.h create mode 100644 drivers/gpu/drm/stm/lvds.c (limited to 'drivers/gpu/drm/stm') diff --git a/drivers/gpu/drm/stm/Kconfig b/drivers/gpu/drm/stm/Kconfig new file mode 100644 index 000000000..635be0ac0 --- /dev/null +++ b/drivers/gpu/drm/stm/Kconfig @@ -0,0 +1,35 @@ +# SPDX-License-Identifier: GPL-2.0-only +config DRM_STM + tristate "DRM Support for STMicroelectronics SoC Series" + depends on DRM && (ARCH_STM32 || COMPILE_TEST) + depends on COMMON_CLK + select DRM_CLIENT_SELECTION + select DRM_KMS_HELPER + select DRM_GEM_DMA_HELPER + select DRM_PANEL_BRIDGE + select VIDEOMODE_HELPERS + select FB_PROVIDE_GET_FB_UNMAPPED_AREA if FB + + help + Enable support for the on-chip display controller on + STMicroelectronics STM32 MCUs. + To compile this driver as a module, choose M here: the module + will be called stm-drm. + +config DRM_STM_DSI + tristate "STMicroelectronics specific extensions for Synopsys MIPI DSI" + depends on DRM_STM + select DRM_DW_MIPI_DSI + help + Choose this option for MIPI DSI support on STMicroelectronics SoC. + +config DRM_STM_LVDS + tristate "STMicroelectronics LVDS Display Interface Transmitter DRM driver" + depends on DRM_STM + help + Enable support for LVDS encoders on STMicroelectronics SoC. + The STM LVDS is a bridge which serialize pixel stream onto + a LVDS protocol. + + To compile this driver as a module, choose M here: the module will be + called lvds. diff --git a/drivers/gpu/drm/stm/Makefile b/drivers/gpu/drm/stm/Makefile new file mode 100644 index 000000000..ad740d617 --- /dev/null +++ b/drivers/gpu/drm/stm/Makefile @@ -0,0 +1,10 @@ +# SPDX-License-Identifier: GPL-2.0-only +stm-drm-y := \ + drv.o \ + ltdc.o + +obj-$(CONFIG_DRM_STM_DSI) += dw_mipi_dsi-stm.o + +obj-$(CONFIG_DRM_STM_LVDS) += lvds.o + +obj-$(CONFIG_DRM_STM) += stm-drm.o diff --git a/drivers/gpu/drm/stm/drv.c b/drivers/gpu/drm/stm/drv.c new file mode 100644 index 000000000..0967b9b34 --- /dev/null +++ b/drivers/gpu/drm/stm/drv.c @@ -0,0 +1,273 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) STMicroelectronics SA 2017 + * + * Authors: Philippe Cornu + * Yannick Fertre + * Fabien Dessenne + * Mickael Reulier + */ + +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "ltdc.h" + +#define STM_MAX_FB_WIDTH 2048 +#define STM_MAX_FB_HEIGHT 2048 /* same as width to handle orientation */ + +static const struct drm_mode_config_funcs drv_mode_config_funcs = { + .fb_create = drm_gem_fb_create, + .atomic_check = drm_atomic_helper_check, + .atomic_commit = drm_atomic_helper_commit, +}; + +static int stm_gem_dma_dumb_create(struct drm_file *file, + struct drm_device *dev, + struct drm_mode_create_dumb *args) +{ + unsigned int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8); + + /* + * in order to optimize data transfer, pitch is aligned on + * 128 bytes, height is aligned on 4 bytes + */ + args->pitch = roundup(min_pitch, 128); + args->height = roundup(args->height, 4); + + return drm_gem_dma_dumb_create_internal(file, dev, args); +} + +DEFINE_DRM_GEM_DMA_FOPS(drv_driver_fops); + +static const struct drm_driver drv_driver = { + .driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC, + .name = "stm", + .desc = "STMicroelectronics SoC DRM", + .major = 1, + .minor = 0, + .patchlevel = 0, + .fops = &drv_driver_fops, + DRM_GEM_DMA_DRIVER_OPS_WITH_DUMB_CREATE(stm_gem_dma_dumb_create), + DRM_FBDEV_DMA_DRIVER_OPS, +}; + +static int drv_load(struct drm_device *ddev) +{ + struct platform_device *pdev = to_platform_device(ddev->dev); + struct ltdc_device *ldev; + int ret; + + DRM_DEBUG("%s\n", __func__); + + ldev = drmm_kzalloc(ddev, sizeof(*ldev), GFP_KERNEL); + if (!ldev) + return -ENOMEM; + + ddev->dev_private = (void *)ldev; + + ret = drmm_mode_config_init(ddev); + if (ret) + return ret; + + /* + * set max width and height as default value. + * this value would be used to check framebuffer size limitation + * at drm_mode_addfb(). + */ + ddev->mode_config.min_width = 0; + ddev->mode_config.min_height = 0; + ddev->mode_config.max_width = STM_MAX_FB_WIDTH; + ddev->mode_config.max_height = STM_MAX_FB_HEIGHT; + ddev->mode_config.funcs = &drv_mode_config_funcs; + ddev->mode_config.normalize_zpos = true; + + ret = ltdc_load(ddev); + if (ret) + return ret; + + drm_mode_config_reset(ddev); + drm_kms_helper_poll_init(ddev); + + platform_set_drvdata(pdev, ddev); + + return 0; +} + +static void drv_unload(struct drm_device *ddev) +{ + DRM_DEBUG("%s\n", __func__); + + drm_kms_helper_poll_fini(ddev); + drm_atomic_helper_shutdown(ddev); + ltdc_unload(ddev); +} + +static __maybe_unused int drv_suspend(struct device *dev) +{ + struct drm_device *ddev = dev_get_drvdata(dev); + struct ltdc_device *ldev = ddev->dev_private; + struct drm_atomic_commit *state; + + WARN_ON(ldev->suspend_state); + + state = drm_atomic_helper_suspend(ddev); + if (IS_ERR(state)) + return PTR_ERR(state); + + ldev->suspend_state = state; + pm_runtime_force_suspend(dev); + + return 0; +} + +static __maybe_unused int drv_resume(struct device *dev) +{ + struct drm_device *ddev = dev_get_drvdata(dev); + struct ltdc_device *ldev = ddev->dev_private; + int ret; + + if (WARN_ON(!ldev->suspend_state)) + return -ENOENT; + + pm_runtime_force_resume(dev); + ret = drm_atomic_helper_resume(ddev, ldev->suspend_state); + if (ret) + pm_runtime_force_suspend(dev); + + ldev->suspend_state = NULL; + + return ret; +} + +static __maybe_unused int drv_runtime_suspend(struct device *dev) +{ + struct drm_device *ddev = dev_get_drvdata(dev); + + DRM_DEBUG_DRIVER("\n"); + ltdc_suspend(ddev); + + return 0; +} + +static __maybe_unused int drv_runtime_resume(struct device *dev) +{ + struct drm_device *ddev = dev_get_drvdata(dev); + + DRM_DEBUG_DRIVER("\n"); + return ltdc_resume(ddev); +} + +static const struct dev_pm_ops drv_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(drv_suspend, drv_resume) + SET_RUNTIME_PM_OPS(drv_runtime_suspend, + drv_runtime_resume, NULL) +}; + +static int stm_drm_platform_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct drm_device *ddev; + int ret; + + DRM_DEBUG("%s\n", __func__); + + ret = aperture_remove_all_conflicting_devices(drv_driver.name); + if (ret) + return ret; + + dma_set_coherent_mask(dev, DMA_BIT_MASK(32)); + + ddev = drm_dev_alloc(&drv_driver, dev); + if (IS_ERR(ddev)) + return PTR_ERR(ddev); + + ret = drv_load(ddev); + if (ret) + goto err_put; + + ret = drm_dev_register(ddev, 0); + if (ret) + goto err_unload; + + drm_client_setup_with_fourcc(ddev, DRM_FORMAT_RGB565); + + return 0; + +err_unload: + drv_unload(ddev); +err_put: + drm_dev_put(ddev); + + return ret; +} + +static void stm_drm_platform_remove(struct platform_device *pdev) +{ + struct drm_device *ddev = platform_get_drvdata(pdev); + + DRM_DEBUG("%s\n", __func__); + + drm_dev_unregister(ddev); + drv_unload(ddev); + drm_dev_put(ddev); +} + +static void stm_drm_platform_shutdown(struct platform_device *pdev) +{ + drm_atomic_helper_shutdown(platform_get_drvdata(pdev)); +} + +static struct ltdc_plat_data stm_drm_plat_data = { + .pad_max_freq_hz = 90000000, +}; + +static struct ltdc_plat_data stm_drm_plat_data_mp25 = { + .pad_max_freq_hz = 150000000, +}; + +static const struct of_device_id drv_dt_ids[] = { + { .compatible = "st,stm32-ltdc", .data = &stm_drm_plat_data, }, + { .compatible = "st,stm32mp251-ltdc", .data = &stm_drm_plat_data_mp25, }, + { .compatible = "st,stm32mp255-ltdc", .data = &stm_drm_plat_data_mp25, }, + { /* end node */ }, +}; +MODULE_DEVICE_TABLE(of, drv_dt_ids); + +static struct platform_driver stm_drm_platform_driver = { + .probe = stm_drm_platform_probe, + .remove = stm_drm_platform_remove, + .shutdown = stm_drm_platform_shutdown, + .driver = { + .name = "stm32-display", + .of_match_table = drv_dt_ids, + .pm = &drv_pm_ops, + }, +}; + +drm_module_platform_driver(stm_drm_platform_driver); + +MODULE_AUTHOR("Philippe Cornu "); +MODULE_AUTHOR("Yannick Fertre "); +MODULE_AUTHOR("Fabien Dessenne "); +MODULE_AUTHOR("Mickael Reulier "); +MODULE_DESCRIPTION("STMicroelectronics ST DRM LTDC driver"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c new file mode 100644 index 000000000..a3eae5b2c --- /dev/null +++ b/drivers/gpu/drm/stm/dw_mipi_dsi-stm.c @@ -0,0 +1,800 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) STMicroelectronics SA 2017 + * + * Authors: Philippe Cornu + * Yannick Fertre + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include