At least sparc64 requires I/O-specific access to framebuffers. This
patch updates the fbdev console accordingly.
For drivers with direct access to the framebuffer memory, the callback
functions in struct fb_ops test for the type of memory and call the rsp
fb_sys_ of fb_cfb_ functions. Read and write operations are implemented
internally by DRM's fbdev helper.
For drivers that employ a shadow buffer, fbdev's blit function retrieves
the framebuffer address as struct dma_buf_map, and uses dma_buf_map
interfaces to access the buffer.
The bochs driver on sparc64 uses a workaround to flag the framebuffer as
I/O memory and avoid a HW exception. With the introduction of struct
dma_buf_map, this is not required any longer. The patch removes the rsp
code from both, bochs and fbdev.
v7:
* use min_t(size_t,) (kernel test robot)
* return the number of bytes read/written, if any (fbdev testcase)
v5:
* implement fb_read/fb_write internally (Daniel, Sam)
v4:
* move dma_buf_map changes into separate patch (Daniel)
* TODO list: comment on fbdev updates (Daniel)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Tested-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201103093015.1063-11-tzimmermann@suse.de
Recent kernels have been reported to panic using the bochs_drm
framebuffer under qemu-system-sparc64 which was bisected to
commit 7a0483ac4f ("drm/bochs: switch to generic drm fbdev emulation").
The backtrace indicates that the shadow framebuffer copy in
drm_fb_helper_dirty_blit_real() is trying to access the real
framebuffer using a virtual address rather than use an IO access
typically implemented using a physical (ASI_PHYS) access on SPARC.
The fix is to replace the memcpy with memcpy_toio() from io.h.
memcpy_toio() uses writeb() where the original fbdev code
used sbus_memcpy_toio(). The latter uses sbus_writeb().
The difference between writeb() and sbus_memcpy_toio() is
that writeb() writes bytes in little-endian, where sbus_writeb() writes
bytes in big-endian. As endian does not matter for byte writes they are
the same. So we can safely use memcpy_toio() here.
Note that this only fixes bochs, in general fbdev helpers still have
issues with mixing up system memory and __iomem space. Fixing that will
require a lot more work.
v3:
- Improved changelog (Daniel)
- Added FIXME to fbdev_use_iomem (Daniel)
v2:
- Added missing __iomem cast (kernel test robot)
- Made changelog readable and fix typos (Mark)
- Add flag to select iomem - and set it in the bochs driver
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reported-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reported-by: kernel test robot <lkp@intel.com>
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20200709193016.291267-1-sam@ravnborg.org
Link: https://patchwork.freedesktop.org/patch/msgid/20200725191012.GA434957@ravnborg.org
The bochs driver (and virtual hardware) requires buffer objects to
reside in video ram to display them to the screen. So it can not
display the framebuffer console because the respective buffer object
is permanently pinned in system memory.
Using a shadow buffer for the console solves this problem. The console
emulation will pin the buffer object only during updates from the shadow
buffer. Otherwise, the bochs driver can freely relocated the buffer
between system memory and video ram.
v2:
* select shadow FB via struct drm_mode_config.prefer_shadow_fbdev
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/315833/
Maarten needs -rc4 backmerged so he can pull in the fbcon notifier
removal topic branch into drm-misc-next.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 3029 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use DRM_FORMAT_HOST_XRGB8888, so we are using the correct format code
on bigendian machines. Also set the quirk_addfb_prefer_host_byte_order
mode_config bit so drm_mode_addfb() asks for the correct format code.
Create our own plane and use drm_crtc_init_with_planes() instead of
depending on the default created by drm_crtc_init(). That way the plane
format list is correct on bigendian machines.
Also re-add the framebuffer format check dropped by "df2052cc92 bochs:
convert to drm_fb_helper_fbdev_setup/teardown".
With this patch applied both ADDFB and ADDFB2 ioctls work correctly in
the bochs-drm.ko driver on big endian machines. Without the patch only
ADDFB (which still seems to be used by the majority of userspace) works
correctly.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180921134704.12826-4-kraxel@redhat.com
Currently unloading bochs_drm (after unbinding the vtconsole) results in
a warning about a leaked connector:
[drm:drm_mode_config_cleanup] *ERROR* connector Virtual-3 leaked!
While investigating a potential fix I noticed that a lot of open-coded
functionality is already implemented elsewhere, so start converting it:
bochs_fbdev_init -> drm_fb_helper_fbdev_setup: trivial (similar impl).
bochs_fbdev_fini -> drm_fb_helper_fbdev_teardown: requires unembedding
"struct drm_framebuffer" from "struct bochs_framebuffer".
Unembedding drm_framebuffer is made easy using drm_gem_fbdev_fb_create
which can replace bochs_fbdev_destroy and custom routines in bochs_mm.c.
For this to work, the GEM object is moved into "drm_framebuffer". After
that, "bochs_framebuffer" is no longer needed and therefore removed.
Remove the unused "size" and "initialized" fields from fb, the latter is
not necessary as drm_fb_helper_fbdev_teardown can be called even if
bochsfb_create fails. This theory was tested by returning early and
late (just before drm_gem_fbdev_fb_create). Both scenarios fail
gracefully although the latter seems to leak the object from
bochsfb_create_object (not a regression).
Guess on the reason for the encoder leak: drm_framebuffer_cleanup was
previously used, but did not destroy much. drm_fb_helper_fbdev_teardown
is now used and calls drm_framebuffer_remove which does a bit more work.
Tested with 'echo 0 > /sys/class/vtconsole/vtcon1/bind; rmmod bochs_drm'
and also with Xorg + fbdev (startx -> xterm). The latter triggered a
warning in ttm_bo_vm_open that existed before, see
https://lkml.kernel.org/r/1464000533-13140-4-git-send-email-mstaudt@suse.de
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Peter Wu <peter@lekensteyn.nl>
Link: http://patchwork.freedesktop.org/patch/msgid/20180906221810.20170-3-peter@lekensteyn.nl
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This will allow __drm_mode_object_file to be extended to perform
access control checks based on the file in use.
v2: Also fix up vboxvideo driver in staging
[airlied: merging early as this is an API change]
Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
