Rename struct dma_buf_map to struct iosys_map and corresponding APIs.
Over time dma-buf-map grew up to more functionality than the one used by
dma-buf: in fact it's just a shim layer to abstract system memory, that
can be accessed via regular load and store, from IO memory that needs to
be acessed via arch helpers.
The idea is to extend this API so it can fulfill other needs, internal
to a single driver. Example: in the i915 driver it's desired to share
the implementation for integrated graphics, which uses mostly system
memory, with discrete graphics, which may need to access IO memory.
The conversion was mostly done with the following semantic patch:
@r1@
@@
- struct dma_buf_map
+ struct iosys_map
@r2@
@@
(
- DMA_BUF_MAP_INIT_VADDR
+ IOSYS_MAP_INIT_VADDR
|
- dma_buf_map_set_vaddr
+ iosys_map_set_vaddr
|
- dma_buf_map_set_vaddr_iomem
+ iosys_map_set_vaddr_iomem
|
- dma_buf_map_is_equal
+ iosys_map_is_equal
|
- dma_buf_map_is_null
+ iosys_map_is_null
|
- dma_buf_map_is_set
+ iosys_map_is_set
|
- dma_buf_map_clear
+ iosys_map_clear
|
- dma_buf_map_memcpy_to
+ iosys_map_memcpy_to
|
- dma_buf_map_incr
+ iosys_map_incr
)
@@
@@
- #include <linux/dma-buf-map.h>
+ #include <linux/iosys-map.h>
Then some files had their includes adjusted and some comments were
update to remove mentions to dma-buf-map.
Since this is not specific to dma-buf anymore, move the documentation to
the "Bus-Independent Device Accesses" section.
v2:
- Squash patches
v3:
- Fix wrong removal of dma-buf.h from MAINTAINERS
- Move documentation from dma-buf.rst to device-io.rst
v4:
- Change documentation title and level
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com
We want to stop gup, which isn't the case if we use vmf_insert_page
and VM_MIXEDMAP, because that does not set pte_special.
The motivation here is to stop get_user_pages from working on buffer
object mmaps in general. Quoting some discussion with Thomas:
On Thu, Jul 22, 2021 at 08:22:43PM +0200, Thomas Zimmermann wrote:
> Am 13.07.21 um 22:51 schrieb Daniel Vetter:
> > We want to stop gup, which isn't the case if we use vmf_insert_page
>
> What is gup?
get_user_pages. It pins memory wherever it is, which badly wreaks at least
ttm and could also cause trouble with cma allocations. In both cases
becaue we can't move/reuse these pages anymore.
Now get_user_pages fails when the memory isn't considered "normal", like
with VM_PFNMAP and using vm_insert_pfn. For consistency across all dma-buf
I'm trying (together with Christian König) to roll this out everywhere,
for fewer surprises.
E.g. for 5.14 iirc we merged a patch to do the same for ttm, where it
closes an actual bug (ttm gets really badly confused when there's suddenly
pinned pages where it thought it can move them).
cma allcoations already use VM_PFNMAP (because that's what dma_mmap is
using underneath), as is anything that's using remap_pfn_range. Worst case
we have to revert this patch for shmem helpers if it breaks something, but
I hope that's not the case. On the ttm side we've also had some fallout
that we needed to paper over with clever tricks.
v2: With this shmem gem helpers now definitely need CONFIG_MMU (0day)
v3: add more depends on MMU. For usb drivers this is a bit awkward,
but really it's correct: To be able to provide a contig mapping of
buffers to userspace on !MMU platforms we'd need to use the cma
helpers for these drivers on those platforms. As-is this wont work.
Also not exactly sure why vm_insert_page doesn't go boom, because that
definitely wont fly in practice since the pages are non-contig to
begin with.
v4: Explain the entire motivation a lot more (Thomas)
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210812131412.2487363-2-daniel.vetter@ffwll.ch
USB devices cannot perform DMA and hence have no dma_mask set in their
device structure. Therefore importing dmabuf into a USB-based driver
fails, which breaks joining and mirroring of display in X11.
For USB devices, pick the associated USB controller as attachment device.
This allows the DRM import helpers to perform the DMA setup. If the DMA
controller does not support DMA transfers, we're out of luck and cannot
import. Our current USB-based DRM drivers don't use DMA, so the actual
DMA device is not important.
Tested by joining/mirroring displays of udl and radeon under Gnome/X11.
v8:
* release dmadev if device initialization fails (Noralf)
* fix commit description (Noralf)
v7:
* fix use-before-init bug in gm12u320 (Dan)
v6:
* implement workaround in DRM drivers and hold reference to
DMA device while USB device is in use
* remove dev_is_usb() (Greg)
* collapse USB helper into usb_intf_get_dma_device() (Alan)
* integrate Daniel's TODO statement (Daniel)
* fix typos (Greg)
v5:
* provide a helper for USB interfaces (Alan)
* add FIXME item to documentation and TODO list (Daniel)
v4:
* implement workaround with USB helper functions (Greg)
* use struct usb_device->bus->sysdev as DMA device (Takashi)
v3:
* drop gem_create_object
* use DMA mask of USB controller, if any (Daniel, Christian, Noralf)
v2:
* move fix to importer side (Christian, Daniel)
* update SHMEM and CMA helpers for new PRIME callbacks
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 6eb0233ec2 ("usb: don't inherity DMA properties for USB devices")
Tested-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org> # v5.10+
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210303133229.3288-1-tzimmermann@suse.de
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Vmap operations may acquire the dmabuf reservation lock, which is not
allowed within atomic commit-tail functions. Therefore move vmap and
vunmap from the damage handler into prepare_fb and cleanup_fb callbacks.
The mapping is provided as GEM shadow-buffered plane. The functions in
the commit tail use the pre-established mapping for damage handling.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210208115538.6430-8-tzimmermann@suse.de
This patch replaces the vmap/vunmap's use of raw pointers in GEM object
functions with instances of struct dma_buf_map. GEM backends are
converted as well. For most of them, this simply changes the returned type.
TTM-based drivers now return information about the location of the memory,
either system or I/O memory. GEM VRAM helpers and qxl now use ttm_bo_vmap()
et al. Amdgpu, nouveau and radeon use drm_gem_ttm_vmap() et al instead of
implementing their own vmap callbacks.
v7:
* init QXL cursor to mapped BO buffer (kernel test robot)
v5:
* update vkms after switch to shmem
v4:
* use ttm_bo_vmap(), drm_gem_ttm_vmap(), et al. (Daniel, Christian)
* fix a trailing { in drm_gem_vmap()
* remove several empty functions instead of converting them (Daniel)
* comment uses of raw pointers with a TODO (Daniel)
* TODO list: convert more helpers to use struct dma_buf_map
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Christian König <christian.koenig@amd.com>
Tested-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201103093015.1063-7-tzimmermann@suse.de
The udl driver contains an implementation of GEM vmap and mmap
operations that is identical to the common SHMEM helper; except
that udl's code uses cached pages by default.
Convert udl to regular SHMEM helper functions. There's no reason
to have udl behave differently from all other SHMEM drivers. The
udl driver uses the SHMEM helper to enable caching.
v3:
* rebased onto Daniel's shmem untangle series
v2:
* implement .gem_create_object with SHMEM helper
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200609090820.20256-3-tzimmermann@suse.de
The udl driver for DisplayLink devices depends on support for host-side
USB controllers, which is enabled with CONFIG_USB. Plain USB support as
given by CONFIG_USB_SUPPORT is not sufficient.
This patch changes dependencies for udl to depend on CONFIG_USB, instead
of CONFIG_USB_SUPPORT. Users will have to enable CONFIG_USB and select a
USB host controller. With this change udl dependencies work the same way
as dependencies for PCI drivers.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200106141016.9562-1-tzimmermann@suse.de
Udl has a single display pipeline with a primary plane; perfect for
simple-pipe helpers. Convert it over. The old encoder and CRTC code
becomes unused and obsolete.
Exported formats for the primary plane are RGB565 and XRGB8888, with
the latter being emulated. The 16-bit format is the default and what
is used when communicating with the device.
This patch enables atomic modesetting for udl devices.
v3:
* remove unused field crtc from struct udl_device
* set crtc_state->no_vblank at beginning of enable()
v2:
* move suspend/resume changes into separate patch
* remove non-atomic code
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191210084905.5570-3-tzimmermann@suse.de
The damage-handler code now invokes dma_buf_{begin,end}_access()
for imported buffers. These calls were missing from the page-flip
and modesetting code paths. The patch also fixes an bug in the
original where an error code was overwritten by the result of
dma_buf_end_cpu_access().
v2:
* only return an error code from dma_buf_end_cpu_access() if
no other error code has been set before
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191206085954.9697-7-tzimmermann@suse.de
Udl's custom implementation for struct drm_gem_object_funcs.free_object
unmaps perma-mapped memory buffer before freeing the buffer object.
After switching to generic fbdev emulation and fixing the damage
handler, no perma-mapped buffers have to be released. Switch to SHMEM's
implementation of free_object.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191114141025.32198-3-tzimmermann@suse.de
