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 <michal.winiarski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240823163048.2676257-4-michal.winiarski@intel.com
Acked-by: James Zhu <James.Zhu@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
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 <jfalempe@redhat.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240822073852.562286-5-jfalempe@redhat.com
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 <hamza.mahfooz@amd.com>
Acked-by: Simon Ser <contact@emersion.fr>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240429164336.1406480-1-jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
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 <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240409163432.352518-3-jfalempe@redhat.com
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
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 <daniel.vetter@ffwll.ch>
Cc: Jocelyn Falempe <jfalempe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240409163432.352518-2-jfalempe@redhat.com
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The mutex was completely pointless in the first place since any
parallel adding of files to this list would result in random
behavior since the list is filled and consumed multiple times.
Completely drop that approach and just create the files directly but
return -ENODEV while opening the file when the minors are not
registered yet.
v2: rebase on debugfs directory rework, limit access before minors are
registered.
Signed-off-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230829110115.3442-5-christian.koenig@amd.com
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Instead of the per minor directories only create a single debugfs
directory for the whole device directly when the device is initialized.
For DRM devices each minor gets a symlink to the per device directory
for now until we can be sure that this isn't useful any more in any way.
Accel devices create only the per device directory and also drops the mid
layer callback to create driver specific files.
v2: cleanup accel component as well
v3: fix typo when debugfs is disabled
v4: call drm_debugfs_dev_fini() during release as well,
some kerneldoc typos fixed
v5: rebased and one more kerneldoc fix
Signed-off-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230829110115.3442-4-christian.koenig@amd.com
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
drm-misc-next for v6.3:
UAPI Changes:
* connector: Support analog-TV mode property
* media: Add MEDIA_BUS_FMT_RGB565_1X24_CPADHI,
MEDIA_BUS_FMT_RGB666_1X18 and MEDIA_BUS_FMT_RGB666_1X24_CPADHI
Cross-subsystem Changes:
* dma-buf: Documentation fixes
* i2c: Introduce i2c_client_get_device_id() helper
Core Changes:
* Improve support for analog TV output
* bridge: Remove unused drm_bridge_chain functions
* debugfs: Add per-device helpers and convert various DRM drivers
* dp-mst: Various fixes
* fbdev emulation: Always pick 32 bpp as default
* KUnit: Add tests for managed helpers; Various cleanups
* panel-orientation: Add quirks for Lenovo Yoga Tab 3 X90F and DynaBook K50
* TTM: Open-code ttm_bo_wait() and remove the helper
Driver Changes:
* Fix preferred depth and bpp values throughout DRM drivers
* Remove #CONFIG_PM guards throughout DRM drivers
* ast: Various fixes
* bridge: Implement i2c's probe_new in various drivers; Fixes; ite-it6505:
Locking fixes, Cache EDID data; ite-it66121: Support IT6610 chip,
Cleanups; lontium-tl9611: Fix HDMI on DragonBoard 845c; parade-ps8640:
Use atomic bridge functions
* gud: Convert to DRM shadow-plane helpers; Perform flushing synchronously
during atomic update
* ili9486: Support 16-bit pixel data
* imx: Split off IPUv3 driver; Various fixes
* mipi-dbi: Convert to DRM shadow-plane helpers plus rsp driver changes;i
Support separate I/O-voltage supply
* mxsfb: Depend on ARCH_MXS or ARCH_MXC
* omapdrm: Various fixes
* panel: Use ktime_get_boottime() to measure power-down delay in various
drivers; Fix auto-suspend delay in various drivers; orisetech-ota5601a:
Add support
* sprd: Cleanups
* sun4i: Convert to new TV-mode property
* tidss: Various fixes
* v3d: Various fixes
* vc4: Convert to new TV-mode property; Support Kunit tests; Cleanups;
dpi: Support RGB565 and RGB666 formats; dsi: Convert DSI driver to
bridge
* virtio: Improve tracing
* vkms: Support small cursors in IGT tests; Various fixes
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
From: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/Y7QIwlfElAYWxRcR@linux-uq9g
I got a null-ptr-deref report:
[drm:drm_dev_init [drm]] *ERROR* Cannot allocate anonymous inode: -12
==================================================================
BUG: KASAN: null-ptr-deref in iput+0x3c/0x4a0
...
Call Trace:
dump_stack_lvl+0x6c/0x8b
kasan_report.cold+0x64/0xdb
__asan_load8+0x69/0x90
iput+0x3c/0x4a0
drm_dev_init_release+0x39/0xb0 [drm]
drm_managed_release+0x158/0x2d0 [drm]
drm_dev_init+0x3a7/0x4c0 [drm]
__devm_drm_dev_alloc+0x55/0xd0 [drm]
mi0283qt_probe+0x8a/0x2b5 [mi0283qt]
spi_probe+0xeb/0x130
...
entry_SYSCALL_64_after_hwframe+0x44/0xae
If drm_fs_inode_new() fails in drm_dev_init(), dev->anon_inode will point
to PTR_ERR(...) instead of NULL. This will result in null-ptr-deref when
drm_fs_inode_free(dev->anon_inode) is called.
drm_dev_init()
drm_fs_inode_new() // fail, dev->anon_inode = PTR_ERR(...)
drm_managed_release()
drm_dev_init_release()
drm_fs_inode_free() // access non-existent anon_inode
Define a temp variable and assign it to dev->anon_inode if the temp
variable is not PTR_ERR.
Fixes: 2cbf7fc671 ("drm: Use drmm_ for drm_dev_init cleanup")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211013114139.4042207-1-wanghai38@huawei.com
On some new laptops the LCD panel has a builtin electronic privacy-screen.
We want to export this functionality as a property on the drm connector
object. But often this functionality is not exposed on the GPU but on some
other (ACPI) device.
This commit adds a privacy-screen class allowing the driver for these
other devices to register themselves as a privacy-screen provider; and
allowing the drm/kms code to get a privacy-screen provider associated
with a specific GPU/connector combo.
Changes in v2:
- Make CONFIG_DRM_PRIVACY_SCREEN a bool which controls if the drm_privacy
code gets built as part of the main drm module rather then making it
a tristate which builds its own module.
- Add a #if IS_ENABLED(CONFIG_DRM_PRIVACY_SCREEN) check to
drm_privacy_screen_consumer.h and define stubs when the check fails.
Together these 2 changes fix several dependency issues.
- Remove module related code now that this is part of the main drm.ko
- Use drm_class as class for the privacy-screen devices instead of
adding a separate class for this
Changes in v3:
- Make the static inline drm_privacy_screen_get_state() stub set sw_state
and hw_state to PRIVACY_SCREEN_DISABLED to squelch an uninitialized
variable warning when CONFIG_DRM_PRIVICAY_SCREEN is not set
Changes in v4:
- Make drm_privacy_screen_set_sw_state() skip calling out to the hw if
hw_state == new_sw_state
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211005202322.700909-3-hdegoede@redhat.com
Now that the legacy PCI support code doesn't need to write to the
drm_driver structure, it can be treated as const through the whole DRM
core, unconditionally. This allows declaring the structure as const in
all drivers, removing one possible attack vector.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Following functions are only used internally, not by drivers:
- devm_drm_dev_init
Also, now that we have a very slick and polished way to allocate a
drm_device with devm_drm_dev_alloc, update all the docs to reflect the
new reality. Mostly this consists of deleting old and misleading
hints. Two main ones:
- it is no longer required that the drm_device base class is first in
the structure. devm_drm_dev_alloc can cope with it being anywhere
- obviously embedded now strongly recommends using devm_drm_dev_alloc
v2: Fix typos (Noralf)
v3: Split out the removal of drm_dev_init, that's blocked on some
discussions on how to convert vgem/vkms/i915-selftests. Adjust commit
message to reflect that.
Cc: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Noralf Trønnes <noralf@tronnes.org> (v2)
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Luben Tuikov <luben.tuikov@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200902072627.3617301-1-daniel.vetter@ffwll.ch
Add a new macro helper to combine the usual init sequence in drivers,
consisting of a kzalloc + devm_drm_dev_init + drmm_add_final_kfree
triplet. This allows us to remove the rather unsightly
drmm_add_final_kfree from all currently merged drivers.
The kerneldoc is only added for this new function. Existing kerneldoc
and examples will be udated at the very end, since once all drivers
are converted over to devm_drm_dev_alloc we can unexport a lot of
interim functions and make the documentation for driver authors a lot
cleaner and less confusing. There will be only one true way to
initialize a drm_device at the end of this, which is going to be
devm_drm_dev_alloc.
v2:
- Actually explain what this is for in the commit message (Sam)
- Fix checkpatch issues (Sam)
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Cc: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200415074034.175360-2-daniel.vetter@ffwll.ch
All collected together to provide a consistent story in one patch,
instead of the somewhat bumpy refactor-evolution leading to this.
Also some thoughts on what the next steps could be:
- Create a macro called devm_drm_dev_alloc() which essentially wraps
the kzalloc(); devm_drm_dev_init(); drmm_add_final_kfree() combo.
Needs to be a macro since we'll have to do some typeof trickery and
casting to make this fully generic for all drivers that embed struct
drm_device into their own thing.
- A lot of the simple drivers now have essentially just
drm_dev_unplug(); drm_atomic_helper_shutdown(); as their
$bus_driver->remove hook. We could create a devm_mode_config_reset
which sets drm_atomic_helper_shutdown as it's cleanup action, and a
devm_drm_dev_register with drm_dev_unplug as it's cleanup action,
and simple drivers wouldn't have a need for a ->remove function at
all, and we could delete them.
- For more complicated drivers we need drmm_ versions of a _lot_ more
things. All the userspace visible objects (crtc, plane, encoder,
crtc), anything else hanging of those (maybe a drmm_get_edid, at
least for panels and other built-in stuff).
Also some more thoughts on why we're not reusing devm_ with maybe a
fake struct device embedded into the drm_device (we can't use the
kdev, since that's in each drm_minor).
- Code review gets extremely tricky, since every time you see a devm_
you need to carefully check whether the fake device (with the
drm_device lifetim) or the real device (with the lifetim of the
underlying physical device and driver binding) are used. That's not
going to help at all, and we have enormous amounts of drivers who
use devm_ where they really shouldn't. Having different types makes
sure the compiler type checks this for us and ensures correctness.
- The set of functions are very much non-overlapping. E.g.
devm_ioremap makes total sense, drmm_ioremap has the wrong lifetime,
since hw resources need to be cleaned out at driver unbind and wont
outlive that like a drm_device. Similar, but other way round for
drmm_connector_init (which is the only correct version, devm_ for
drm_connector is just buggy). Simply not having the wrong version
again prevents bugs.
Finally I guess this opens a huge todo for all the drivers. I'm
semi-tempted to do a tree-wide s/devm_kzalloc/drmm_kzalloc/ since most
likely that'll fix an enormous amount of bugs and most likely not
cause any issues at all (aside from maybe holding onto memory slightly
too long).
v2:
- Doc improvements from Laurent.
- Also add kerneldoc for the new drmm_add_action_or_reset.
v3:
- Remove kerneldoc for drmm_remove_action.
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
fixup docs
Link: https://patchwork.freedesktop.org/patch/msgid/20200323144950.3018436-52-daniel.vetter@ffwll.ch
drm_mode_config_cleanup is idempotent, so no harm in calling this
twice. This allows us to gradually switch drivers over by removing
explicit drm_mode_config_cleanup calls.
With this step it's now also possible that (at least for simple
drivers) automatic resource cleanup can be done correctly without a
drm_driver->release hook. Therefore allow this now in
devm_drm_dev_init().
Also with drmm_ explicit drm_driver->release hooks are kinda not the
best option: Drivers can always just register their current release
hook with drmm_add_action, but even better they could split them up to
simplify the unwinding for the driver load failure case. So deprecate
that hook to discourage future users.
v2: Fixup the example in the kerneldoc too.
v3:
- For paranoia, double check that minor->dev == dev in the release
hook, because I botched the pointer math in the drmm library.
- Call drm_mode_config_cleanup when drmm_add_action fails, we'd be
missing some mutex_destroy and ida_cleanup otherwise (Laurent)
v4: Add a drmm_add_action_or_reset (like devm_ has) to encapsulate this
pattern (Noralf).
v5: Fix oversight in the new drmm_add_action_or_reset macro (Noralf)
v4: Review from Sam:
- drmm_mode_config_init wrapper (also suggested by Thomas)
- improve commit message, explain better why ->relase is deprecated
v5:
- Make drmm_ the main function, with the old one as compat wrapper
(Sam)
- Add FIXME comments to drm_mode_config_cleanup/init() that drivers
shouldn't use these anymore.
- Move drmm_add_action_or_reset helper to an earlier patch.
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: "Noralf Trønnes" <noralf@tronnes.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200323144950.3018436-27-daniel.vetter@ffwll.ch
Nothing special here, except that this is the first time that we
automatically clean up something that's initialized with an explicit
driver call. But the cleanup was done at the very end of the release
sequence for all drivers, and that's still the case. At least without
more uses of drmm_ through explicit driver calls.
Also for this one we need drmm_kcalloc, so lets add those.
The motivation here is to allow us to remove the explicit calls to
drm_dev_fini() from all drivers.
v2: Sort includes (Laurent)
v3: Motivate the change in the commit message better (Sam)
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200323144950.3018436-25-daniel.vetter@ffwll.ch
The cleanup here is somewhat tricky, since we can't tell apart the
allocated minor index from 0. So register a cleanup action first, and
if the index allocation fails, unregister that cleanup action again to
avoid bad mistakes.
The kdev for the minor already handles NULL, so no problem there.
Hence add drmm_remove_action() to the drm_managed library.
v2: Make pointer math around void ** consistent with what Laurent
suggested.
v3: Use drmm_add_action_or_reset and remove drmm_remove_action. Noticed
because of some questions from Thomas. This also means we need to move
the drmm_add_action_or_reset helper earlier in the series.
v4: Uh ... fix slightly embarrassing bug CI spotted.
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200324203936.3330994-1-daniel.vetter@ffwll.ch
We have lots of these. And the cleanup code tends to be of dubious
quality. The biggest wrong pattern is that developers use devm_, which
ties the release action to the underlying struct device, whereas
all the userspace visible stuff attached to a drm_device can long
outlive that one (e.g. after a hotunplug while userspace has open
files and mmap'ed buffers). Give people what they want, but with more
correctness.
Mostly copied from devres.c, with types adjusted to fit drm_device and
a few simplifications - I didn't (yet) copy over everything. Since
the types don't match code sharing looked like a hopeless endeavour.
For now it's only super simplified, no groups, you can't remove
actions (but kfree exists, we'll need that soon). Plus all specific to
drm_device ofc, including the logging. Which I didn't bother to make
compile-time optional, since none of the other drm logging is compile
time optional either.
One tricky bit here is the chicken&egg between allocating your
drm_device structure and initiliazing it with drm_dev_init. For
perfect onion unwinding we'd need to have the action to kfree the
allocation registered before drm_dev_init registers any of its own
release handlers. But drm_dev_init doesn't know where exactly the
drm_device is emebedded into the overall structure, and by the time it
returns it'll all be too late. And forcing drivers to be able clean up
everything except the one kzalloc is silly.
Work around this by having a very special final_kfree pointer. This
also avoids troubles with the list head possibly disappearing from
underneath us when we release all resources attached to the
drm_device.
v2: Do all the kerneldoc at the end, to avoid lots of fairly pointless
shuffling while getting everything into shape.
v3: Add static to add/del_dr (Neil)
Move typo fix to the right patch (Neil)
v4: Enforce contract for drmm_add_final_kfree:
Use ksize() to check that the drm_device is indeed contained somewhere
in the final kfree(). Because we need that or the entire managed
release logic blows up in a pile of use-after-frees. Motivated by a
discussion with Laurent.
v5: Review from Laurent:
- %zu instead of casting size_t
- header guards
- sorting of includes
- guarding of data assignment if we didn't allocate it for a NULL
pointer
- delete spurious newline
- cast void* data parameter correctly in ->release call, no idea how
this even worked before
v6: Review from Sam
- Add the kerneldoc for the managed sub-struct back in, even if it
doesn't show up in the generated html somehow.
- Explain why __always_inline.
- Fix bisectability around the final kfree() in drm_dev_relase(). This
is just interim code which will disappear again.
- Some whitespace polish.
- Add debug output when drmm_add_action or drmm_kmalloc fail.
v7: My bisectability fix wasn't up to par as noticed by smatch.
v8: Remove unecessary {} around if else
v9: Use kstrdup_const, which requires kfree_const and introducing a free_dr()
helper (Thomas).
v10: kfree_const goes boom on the plain "kmalloc" assignment, somehow
we need to wrap that in kstrdup_const() too!! Also renumber revision
log, I somehow reset it midway thruh.
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Neil Armstrong <narmstrong@baylibre.com
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200324124540.3227396-1-daniel.vetter@ffwll.ch
