Add the first version of the VM_BIND locking document which is
intended to be part of the xe driver upstreaming agreement.
The document describes and discuss the locking used during exec-
functions, evicton and for userptr gpu-vmas. Intention is to be using the
same nomenclature as the drm-vm-bind-async.rst.
v2:
- s/gvm/gpu_vm/g (Rodrigo Vivi)
- Clarify the userptr seqlock with a pointer to mm/mmu_notifier.c
(Rodrigo Vivi)
- Adjust commit message accordingly.
- Add SPDX license header.
v3:
- Large update to align with the drm_gpuvm manager locking
- Add "Efficient userptr gpu_vma exec function iteration" section
- Add "Locking at bind- and unbind time" section.
v4:
- Fix tabs vs space errors by untabifying (Rodrigo Vivi)
- Minor style fixes and typos (Rodrigo Vivi)
- Clarify situations where stale GPU mappings are occurring and how
access through these mappings are blocked. (Rodrigo Vivi)
- Insert into the toctree in implementation_guidelines.rst
v5:
- Add a section about recoverable page-faults.
- Use local references to other documentation where possible
(Bagas Sanjaya)
- General documentation fixes and typos (Danilo Krummrich and
Boris Brezillon)
- Improve the documentation around locks that need to be grabbed from the
dm-fence critical section (Boris Brezillon)
- Add more references to the DRM GPUVM helpers (Danilo Krummrich and
Boriz Brezillon)
- Update the rfc/xe.rst document.
v6:
- Rework wording to improve readability (Boris Brezillon, Rodrigo Vivi,
Bagas Sanjaya)
- Various minor fixes across the document (Boris Brezillon)
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Danilo Krummrich <dakr@redhat.com>
Acked-by: John Hubbard <jhubbard@nvidia.com> # Documentation/core-api/pin_user_pages.rst changes
Link: https://patchwork.freedesktop.org/patch/msgid/20231129090637.2629-1-thomas.hellstrom@linux.intel.com
Drop the default implementations for file read, write and mmap
operations. Each fbdev driver must now provide an implementation
and select any necessary helpers. If no implementation has been
set, fbdev returns an errno code to user space. The code is the
same as if the operation had not been set in the file_operations
struct.
This change makes the fbdev helpers for I/O memory optional. Most
systems only use system-memory framebuffers via DRM's fbdev emulation.
v2:
* warn once if I/O callbacks are missing (Javier)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-33-tzimmermann@suse.de
Test in framebuffer read, write and drawing helpers if FBINFO_VIRTFB
has been set correctly. Framebuffers in I/O memory should only be
accessed with the architecture's respective helpers. Framebuffers
in system memory should be accessed with the regular load and
store operations. Presumably not all drivers get this right, so we
now warn about it.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-32-tzimmermann@suse.de
Move the default fb_mmap code for I/O address spaces into the helper
function fb_io_mmap(). The helper can either be called via struct
fb_ops.fb_mmap or as the default if no fb_mmap has been set. Also
set the new helper in __FB_DEFAULT_IOMEM_OPS_MMAP.
In the mid-term, fb_io_mmap() is supposed to become optional. Fbdev
drivers will initialize their struct fb_ops.fb_mmap to the helper
and select a corresponding Kconfig token. The helper can then be made
optional at compile time.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-31-tzimmermann@suse.de
If a driver sets struct fb_ops.fb_mmap, the fbdev core automatically
calls pgprot_decrypted(). But the default fb_mmap code doesn't handle
pgprot_decrypted().
Move the call to pgprot_decrypted() into each drivers' fb_mmap function.
This only concerns fb_mmap functions for system and DMA memory. For
I/O memory, which is the default case, nothing changes. The fb_mmap
for I/O-memory can later be moved into a helper as well.
DRM's fbdev emulation handles pgprot_decrypted() internally via the
Prime helpers. Fbdev doesn't have to do anything in this case. In
cases where DRM uses deferred I/O, this patch updates fb_mmap correctly.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-30-tzimmermann@suse.de
Initialize the instance of struct fb_ops with fbdev initializer
macros for framebuffers in I/O address space. Set the read/write,
draw and mmap callbacks to the correct implementation and avoid
implicit defaults. Also select the necessary helpers in Kconfig.
Fbdev drivers sometimes rely on the callbacks being NULL for a
default I/O-memory-based implementation to be invoked; hence
requiring the I/O helpers to be built in any case. Setting all
callbacks in all drivers explicitly will allow to make the I/O
helpers optional. This benefits systems that do not use these
functions.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-25-tzimmermann@suse.de
Initialize the instance of struct fb_ops with fbdev initializer
macros for framebuffers in DMA-able address space. This explictily
sets the read/write, draw and mmap callbacks to the correct default
implementation. Also select the necessary helpers in Kconfig.
Fbdev drivers sometimes rely on the callbacks being NULL for a
default implementation to be invoked; hence requireing the I/O
helpers to be built in any case. Setting all callbacks in all
drivers explicitly will allow to make the I/O helpers optional.
This benefits systems that do not use these functions.
Set the callbacks via macros. No functional changes.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-24-tzimmermann@suse.de
Initialize the instance of struct fb_ops with fbdev initializer
macros for framebuffers in DMA-able virtual address space. Set the
read/write, draw and mmap callbacks to the correct implementation
and avoid implicit defaults. Also select the necessary helpers in
Kconfig.
Fbdev drivers sometimes rely on the callbacks being NULL for a
default I/O-memory-based implementation to be invoked; hence
requiring the I/O helpers to be built in any case. Setting all
callbacks in all drivers explicitly will allow to make the I/O
helpers optional. This benefits systems that do not use these
functions.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-23-tzimmermann@suse.de
Initialize the instance of struct fb_ops with fbdev initializer
macros for framebuffers in I/O address space. Set the read/write,
draw and mmap callbacks to the correct implementation and avoid
implicit defaults. Also select the necessary helpers in Kconfig.
The driver previously selected drawing ops for system memory
although it operates on I/O memory. Fixed now.
Fbdev drivers sometimes rely on the callbacks being NULL for a
default I/O-memory-based implementation to be invoked; hence
requiring the I/O helpers to be built in any case. Setting all
callbacks in all drivers explicitly will allow to make the I/O
helpers optional. This benefits systems that do not use these
functions.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-22-tzimmermann@suse.de
Initialize the instance of struct fb_ops with fbdev initializer
macros for framebuffers in I/O address space. This explictily sets
the read/write, draw and mmap callbacks to the correct default
implementation.
Fbdev drivers sometimes rely on the callbacks being NULL for a
default implementation to be invoked; hence requireing the I/O
helpers to be built in any case. Setting all callbacks in all
drivers explicitly will allow to make the I/O helpers optional.
This benefits systems that do not use these functions.
Set the callbacks via macros. No functional changes.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Andy Walls <awalls@md.metrocast.net>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: linux-media@vger.kernel.org
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-21-tzimmermann@suse.de
Initialize the instance of struct fb_ops with fbdev initializer
macros for framebuffers in virtual address space. Set the read/write,
draw and mmap callbacks to the correct implementation and avoid
implicit defaults. Also select the necessary helpers in Kconfig.
Fbdev drivers sometimes rely on the callbacks being NULL for a
default I/O-memory-based implementation to be invoked; hence
requiring the I/O helpers to be built in any case. Setting all
callbacks in all drivers explicitly will allow to make the I/O
helpers optional. This benefits systems that do not use these
functions.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: linuxppc-dev@lists.ozlabs.org
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-20-tzimmermann@suse.de
Initialize the instance of struct fb_ops with fbdev initializer
macros for framebuffers in DMA-able virtual address space. Set the
read/write, draw and mmap callbacks to the correct implementation
and avoid implicit defaults. Also select the necessary helpers in
Kconfig.
Fbdev drivers sometimes rely on the callbacks being NULL for a
default I/O-memory-based implementation to be invoked; hence
requiring the I/O helpers to be built in any case. Setting all
callbacks in all drivers explicitly will allow to make the I/O
helpers optional. This benefits systems that do not use these
functions.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-18-tzimmermann@suse.de
Initialize the instance of struct fb_ops with fbdev initializer
macros for framebuffers in DMA-able virtual address space. Set the
read/write, draw and mmap callbacks to the correct implementation
and avoid implicit defaults. Also select the necessary helpers in
Kconfig.
The driver uses a mixture of DMA helpers and deferred I/O. That
probably needs fixing by a driver maintainer.
Fbdev drivers sometimes rely on the callbacks being NULL for a
default I/O-memory-based implementation to be invoked; hence
requiring the I/O helpers to be built in any case. Setting all
callbacks in all drivers explicitly will allow to make the I/O
helpers optional. This benefits systems that do not use these
functions.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-14-tzimmermann@suse.de
Initialize the instance of struct fb_ops with fbdev initializer
macros for framebuffers in virtual address space. Set the read/write,
draw and mmap callbacks to the correct implementation and avoid
implicit defaults. Also select the necessary helpers in Kconfig.
Fbdev drivers sometimes rely on the callbacks being NULL for a
default I/O-memory-based implementation to be invoked; hence
requiring the I/O helpers to be built in any case. Setting all
callbacks in all drivers explicitly will allow to make the I/O
helpers optional. This benefits systems that do not use these
functions.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Robin van der Gracht <robin@protonic.nl>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Robin van der Gracht <robin@protonic.nl>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-11-tzimmermann@suse.de
Initialize the instance of struct fb_ops with fbdev initializer
macros for framebuffers in virtual address space. Set the read/write,
draw and mmap callbacks to the correct implementation and avoid
implicit defaults. Also select the necessary helpers in Kconfig.
Fbdev drivers sometimes rely on the callbacks being NULL for a
default I/O-memory-based implementation to be invoked; hence
requiring the I/O helpers to be built in any case. Setting all
callbacks in all drivers explicitly will allow to make the I/O
helpers optional. This benefits systems that do not use these
functions.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-9-tzimmermann@suse.de
Implement the driver's fops with the generator macros for deferred
I/O. Only requires per-driver code for the on-scren scanout buffer.
The generated helpers implement reading, writing and drawing on top
of that. Also update the selected Kconfig tokens accordingly.
Actual support for deferred I/O is missing from the driver. So
writing to memory-mapped pages does not automatically update the
scanout buffer.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Jaya Kumar <jayalk@intworks.biz>
Acked-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-7-tzimmermann@suse.de
Initialize the instance of struct fb_ops with fbdev initializer
macros for framebuffers in virtual address space. Set the read/write,
draw and mmap callbacks to the correct implementation and avoid
implicit defaults. Also select the necessary helpers in Kconfig.
Fbdev drivers sometimes rely on the callbacks being NULL for a
default I/O-memory-based implementation to be invoked; hence
requiring the I/O helpers to be built in any case. Setting all
callbacks in all drivers explicitly will allow to make the I/O
helpers optional. This benefits systems that do not use these
functions.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-5-tzimmermann@suse.de
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.
There is one error path in tilcdc_pdev_remove() that potentially could
yield a non-zero return code. In this case an error message describing
the failure is emitted now instead of
remove callback returned a non-zero value. This will be ignored.
before. Otherwise there is no difference. Also note that currently
tilcdc_get_external_components() doesn't return negative values.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jyri Sarha <jyri.sarha@iki.fi>
Link: https://patchwork.freedesktop.org/patch/msgid/20231102165640.3307820-34-u.kleine-koenig@pengutronix.de
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Tested-by: Jyri Sarha <jyri.sarha@iki.fi>
Detect device type and config mode in the PCI probe helper, but leave
DRM device initialization where it is. Structures the driver probe and
setup code into a detection and an initialization phase.
A later patch can add branching to the device-initialization code. Each
chip type can have it own initializer function, if necessary.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231116100240.22975-11-tzimmermann@suse.de
