kernel/linux.git/drivers/gpu/drm/drm_drv.c, branch v6.12.80

drm: Expand max DRM device number to full MINORBITS

2024-08-26T15:06:22+00:00

Having a limit of 64 DRM devices is not good enough for modern world where we have multi-GPU servers, SR-IOV virtual functions and virtual devices used for testing. Let's utilize full minor range for DRM devices. To avoid regressing the existing userspace, we're still maintaining the numbering scheme where 0-63 is used for primary, 64-127 is reserved (formerly for control) and 128-191 is used for render. For minors >= 192, we're allocating minors dynamically on a first-come, first-served basis. Signed-off-by: Michał Winiarski Link: https://patchwork.freedesktop.org/patch/msgid/20240823163048.2676257-4-michal.winiarski@intel.com Acked-by: James Zhu Acked-by: Christian König Signed-off-by: Christian König

accel: Use XArray instead of IDR for minors

2024-08-26T15:06:22+00:00

Accel minor management is based on DRM (and is also using struct drm_minor internally), since DRM is using XArray for minors, it makes sense to also convert accel. As the two implementations are identical (only difference being the underlying xarray), move the accel_minor_* functionality to DRM. Signed-off-by: Michał Winiarski Acked-by: James Zhu Acked-by: Christian König Link: https://patchwork.freedesktop.org/patch/msgid/20240823163048.2676257-3-michal.winiarski@intel.com Signed-off-by: Christian König

drm: Use XArray instead of IDR for minors

2024-08-26T15:06:16+00:00

IDR is deprecated, and since XArray manages its own state with internal locking, it simplifies the locking on DRM side. Additionally, don't use the IRQ-safe variant, since operating on drm minor is not done in IRQ context. Suggested-by: Matthew Wilcox Signed-off-by: Michał Winiarski Acked-by: James Zhu Acked-by: Christian König Link: https://patchwork.freedesktop.org/patch/msgid/20240823163048.2676257-2-michal.winiarski@intel.com Signed-off-by: Christian König

drm/panic: Add a QR code panic screen

2024-08-23T14:55:35+00:00

This patch adds a new panic screen, with a QR code and the kmsg data embedded. If DRM_PANIC_SCREEN_QR_CODE_URL is set, then the kmsg data will be compressed with zlib and encoded as a numerical segment, and appended to the URL as a URL parameter. This allows to save space, and put about ~7500 bytes of kmsg data, in a V40 QR code. Linux distributions can customize the URL, and put a web frontend to directly open a bug report with the kmsg data. Otherwise the kmsg data will be encoded as a binary segment (ie raw ascii) and only a maximum of 2953 bytes of kmsg data will be available in the QR code. You can also limit the QR code size with DRM_PANIC_SCREEN_QR_VERSION. Signed-off-by: Jocelyn Falempe Reviewed-by: Alice Ryhl Link: https://patchwork.freedesktop.org/patch/msgid/20240822073852.562286-5-jfalempe@redhat.com

drm: deprecate driver date

2024-05-08T12:31:58+00:00

The driver date serves no useful purpose, because it's hardly ever updated. The information is misleading at best. As described in Documentation/gpu/drm-internals.rst: The driver date, formatted as YYYYMMDD, is meant to identify the date of the latest modification to the driver. However, as most drivers fail to update it, its value is mostly useless. The DRM core prints it to the kernel log at initialization time and passes it to userspace through the DRM_IOCTL_VERSION ioctl. Stop printing the driver date at init, and start returning the empty string "" as driver date through the DRM_IOCTL_VERSION ioctl. The driver date initialization in drivers and the struct drm_driver date member can be removed in follow-up. Reviewed-by: Hamza Mahfooz Acked-by: Simon Ser Reviewed-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20240429164336.1406480-1-jani.nikula@intel.com Signed-off-by: Jani Nikula

drm/fbdev: Clean up fbdev documentation

2024-05-02T09:33:34+00:00

Rewrite some docs that are not up-to-date any longer. Remove the TODO item for fbdev-generic conversion, as the helper has been replaced. Make documentation for DMA, SHMEM and TTM emulation available. Signed-off-by: Thomas Zimmermann Cc: Jonathan Corbet Reviewed-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20240419083331.7761-44-tzimmermann@suse.de

drm/panic: Add a drm panic handler

2024-04-15T14:12:49+00:00

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) v4 * Use drm_fb_r1_to_32bit for fonts (Thomas Zimmermann) * Remove the default y to DRM_PANIC config option (Thomas Zimmermann) * Add foreground/background color config option * Fix the bottom lines not painted if the framebuffer height is not a multiple of the font height. * Automatically register the device to drm_panic, if the function get_scanout_buffer exists. (Thomas Zimmermann) v5 * Change the drawing API, use drm_fb_blit_from_r1() to draw the font. * Also add drm_fb_fill() to fill area with background color. * Add draw_pixel_xy() API for drivers that can't provide a linear buffer. * Add a flush() callback for drivers that needs to synchronize the buffer. * Add a void *private field, so drivers can pass private data to draw_pixel_xy() and flush(). v6 * Fix sparse warning for panic_msg and logo. v7 * Add select DRM_KMS_HELPER for the color conversion functions. v8 * Register directly each plane to the panic notifier (Sima) * Add raw_spinlock to properly handle concurrency (Sima) * Register plane instead of device, to avoid looping through plane list, and simplify code. * Replace get_scanout_buffer() logic with drm_panic_set_buffer() (Thomas Zimmermann) * Removed the draw_pixel_xy() API, will see later if it can be added back. v9 * Revert to using get_scanout_buffer() (Sima) * Move get_scanout_buffer() and panic_flush() to the plane helper functions (Thomas Zimmermann) * Register all planes with get_scanout_buffer() to the panic notifier * Use drm_panic_lock() to protect against race (Sima) v10 * Move blit and fill functions back in drm_panic (Thomas Zimmermann). * Simplify the text drawing functions. * Use kmsg_dumper instead of panic_notifier (Sima). v12 * Use array for map and pitch in struct drm_scanout_buffer to support multi-planar format later. (Thomas Zimmermann) * Better indent struct drm_scanout_buffer declaration. (Thomas Zimmermann) Signed-off-by: Jocelyn Falempe Link: https://patchwork.freedesktop.org/patch/msgid/20240409163432.352518-3-jfalempe@redhat.com Acked-by: Daniel Vetter

drm/panic: Add drm panic locking

2024-04-15T14:11:26+00:00

Rough sketch for the locking of drm panic printing code. The upshot of this approach is that we can pretty much entirely rely on the atomic commit flow, with the pair of raw_spin_lock/unlock providing any barriers we need, without having to create really big critical sections in code. This also avoids the need that drivers must explicitly update the panic handler state, which they might forget to do, or not do consistently, and then we blow up in the worst possible times. It is somewhat racy against a concurrent atomic update, and we might write into a buffer which the hardware will never display. But there's fundamentally no way to avoid that - if we do the panic state update explicitly after writing to the hardware, we might instead write to an old buffer that the user will barely ever see. Note that an rcu protected deference of plane->state would give us the the same guarantees, but it has the downside that we then need to protect the plane state freeing functions with call_rcu too. Which would very widely impact a lot of code and therefore doesn't seem worth the complexity compared to a raw spinlock with very tiny critical sections. Plus rcu cannot be used to protect access to peek/poke registers anyway, so we'd still need it for those cases. Peek/poke registers for vram access (or a gart pte reserved just for panic code) are also the reason I've gone with a per-device and not per-plane spinlock, since usually these things are global for the entire display. Going with per-plane locks would mean drivers for such hardware would need additional locks, which we don't want, since it deviates from the per-console takeoverlocks design. Longer term it might be useful if the panic notifiers grow a bit more structure than just the absolute bare EXPORT_SYMBOL(panic_notifier_list) - somewhat aside, why is that not EXPORT_SYMBOL_GPL ... If panic notifiers would be more like console drivers with proper register/unregister interfaces we could perhaps reuse the very fancy console lock with all it's check and takeover semantics that John Ogness is developing to fix the console_lock mess. But for the initial cut of a drm panic printing support I don't think we need that, because the critical sections are extremely small and only happen once per display refresh. So generally just 60 tiny locked sections per second, which is nothing compared to a serial console running a 115kbaud doing really slow mmio writes for each byte. So for now the raw spintrylock in drm panic notifier callback should be good enough. Another benefit of making panic notifiers more like full blown consoles (that are used in panics only) would be that we get the two stage design, where first all the safe outputs are used. And then the dangerous takeover tricks are deployed (where for display drivers we also might try to intercept any in-flight display buffer flips, which if we race and misprogram fifos and watermarks can hang the memory controller on some hw). For context the actual implementation on the drm side is by Jocelyn and this patch is meant to be combined with the overall approach in v7 (v8 is a bit less flexible, which I think is the wrong direction): https://lore.kernel.org/dri-devel/20240104160301.185915-1-jfalempe@redhat.com/ Note that the locking is very much not correct there, hence this separate rfc. Starting from v10, I (Jocelyn) have included this patch in the drm_panic series, and done the corresponding changes. v2: - fix authorship, this was all my typing - some typo oopsies - link to the drm panic work by Jocelyn for context v10: - Use spinlock_irqsave/restore (John Ogness) v11: - Use macro instead of inline functions for drm_panic_lock/unlock (John Ogness) Signed-off-by: Daniel Vetter Cc: Jocelyn Falempe Cc: Andrew Morton Cc: "Peter Zijlstra (Intel)" Cc: Lukas Wunner Cc: Petr Mladek Cc: Steven Rostedt Cc: John Ogness Cc: Sergey Senozhatsky Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Thomas Zimmermann Cc: David Airlie Cc: Daniel Vetter Signed-off-by: Jocelyn Falempe Link: https://patchwork.freedesktop.org/patch/msgid/20240409163432.352518-2-jfalempe@redhat.com Acked-by: Daniel Vetter

drm: Remove support for legacy drivers

2023-12-06T09:08:28+00:00

Remove all hooks and calls into code for user-space mode setting from the DRM core. Without the drivers and ioctl entry points, none of this is required any longer. Signed-off-by: Thomas Zimmermann Reviewed-by: David Airlie Reviewed-by: Daniel Vetter Acked-by: Alex Deucher Link: https://patchwork.freedesktop.org/patch/msgid/20231122122449.11588-11-tzimmermann@suse.de

drm/drv: propagate errors from drm_modeset_register_all()

2023-12-04T08:42:32+00:00

In case the drm_modeset_register_all() function fails, its error code will be ignored. Instead make the drm_dev_register() bail out in case of such an error. Fixes: 79190ea2658a ("drm: Add callbacks for late registering") Reviewed-by: Neil Armstrong Signed-off-by: Dmitry Baryshkov Signed-off-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20231202225552.1283638-1-dmitry.baryshkov@linaro.org