Linaro-mm-sig April 2014

linaro-mm-sig@lists.linaro.org

8 participants
10 discussions

Re: [Linaro-mm-sig] [RFC] dma-buf: Implement test module

by Thierry Reding

On Tue, Mar 25, 2014 at 07:01:10PM +0100, Sam Ravnborg wrote: > > > > There are two things that don't work too well with this. First this > > causes the build to break if the build machine doesn't have the new > > public header (include/uapi/linux/dma-buf.h) installed yet. So the only > > way to make this work would be by building the kernel once with SAMPLES > > disabled, install the headers and then build again with SAMPLES enabled. > > Which really isn't very nice. > > > > One other option that I've tried is to modify the include path so that > > the test program would get the in-tree copy of the public header file, > > but that didn't build properly either because the header files aren't > > properly sanitized and therefore the compiler complains about it > > (include/uapi/linux/types.h). > > > > One other disadvantage of carrying the sample program in the tree is > > that there's only infrastructure to build programs natively on the build > > machine. That's somewhat unfortunate because if you want to run the test > > program on a different architecture you have to either compile the > > kernel natively on that architecture (which isn't very practical on many > > embedded devices) or cross-compile manually. > > > > I think a much nicer solution would be to add infrastructure to cross- > > compile these test programs, so that they end up being built for the > > same architecture as the kernel image (i.e. using CROSS_COMPILE). > > > > Adding Michal and the linux-kbuild mailing list, perhaps this has been > > discussed before, or maybe somebody has a better idea on how to solve > > this. > I actually looked into this some time ago. > May try to dust off the patch. > IIRC the kernel provided headers were used for building - not the one installed on the machine. > And crosscompile were supported. That sounds exactly like what I'd want for this. If you need any help, please let me know. Thanks, Thierry

9 years, 9 months

[PATCH 0/2] Updates to fence api

by Maarten Lankhorst

The following series implements small updates to the fence api. I've found them useful when implementing the fence API in ttm and i915. The last patch enables RCU on top of the api. I've found this less useful, but it was the condition on which Thomas Hellstrom was ok with converting TTM to fence, so I had to keep it in. If nobody objects I'll probably merge that patch through drm, because some care is needed in ttm before it can flip the switch on rcu. --- Maarten Lankhorst (2): reservation: update api and add some helpers [RFC] reservation: add suppport for read-only access using rcu

9 years, 11 months

[PATCH 0/6] dma-buf synchronization patches (updated)

by Maarten Lankhorst

The following series implements fence and converts dma-buf and android sync to use it. Patch 5 and 6 add support for polling to dma-buf, blocking until all fences are signaled. Patches that received some minor updates: - seqno fence (wait condition member added) - android (whitespace changes and a comment removed) - add poll support to dma-buf (added comment) --- Maarten Lankhorst (6): fence: dma-buf cross-device synchronization (v17) seqno-fence: Hardware dma-buf implementation of fencing (v5) dma-buf: use reservation objects android: convert sync to fence api, v5 reservation: add support for fences to enable cross-device synchronisation dma-buf: add poll support, v3 Documentation/DocBook/device-drivers.tmpl | 3 drivers/base/Kconfig | 9 drivers/base/Makefile | 2 drivers/base/dma-buf.c | 130 +++ drivers/base/fence.c | 467 ++++++++++++ drivers/gpu/drm/drm_prime.c | 8 drivers/gpu/drm/exynos/exynos_drm_dmabuf.c | 2 drivers/gpu/drm/i915/i915_gem_dmabuf.c | 2 drivers/gpu/drm/nouveau/nouveau_drm.c | 1 drivers/gpu/drm/nouveau/nouveau_gem.h | 1 drivers/gpu/drm/nouveau/nouveau_prime.c | 7 drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c | 2 drivers/gpu/drm/radeon/radeon_drv.c | 2 drivers/gpu/drm/radeon/radeon_prime.c | 8 drivers/gpu/drm/ttm/ttm_object.c | 2 drivers/media/v4l2-core/videobuf2-dma-contig.c | 2 drivers/staging/android/Kconfig | 1 drivers/staging/android/Makefile | 2 drivers/staging/android/ion/ion.c | 2 drivers/staging/android/sw_sync.c | 4 drivers/staging/android/sync.c | 903 ++++++++---------------- drivers/staging/android/sync.h | 82 +- drivers/staging/android/sync_debug.c | 247 +++++++ drivers/staging/android/trace/sync.h | 12 include/drm/drmP.h | 2 include/linux/dma-buf.h | 21 - include/linux/fence.h | 329 +++++++++ include/linux/reservation.h | 20 + include/linux/seqno-fence.h | 119 +++ include/trace/events/fence.h | 125 +++ 30 files changed, 1863 insertions(+), 654 deletions(-) create mode 100644 drivers/base/fence.c create mode 100644 drivers/staging/android/sync_debug.c create mode 100644 include/linux/fence.h create mode 100644 include/linux/seqno-fence.h create mode 100644 include/trace/events/fence.h -- Signature

9 years, 11 months

[PATCH v1 00/19] Add DRM for stih4xx platforms

by Benjamin Gaignard

This series of patches add the support of DRM/KMS drivers for STMicroelectronics chipsets stih416 and stih407. Hardware is split in two main blocks: Compositor and TVout. Each of them includes specific hardware IPs and the display timing are controlled by a specific Video Timing Generator hardware IP (VTG). Compositor is made of the follow hardware IPs: - GDP (Generic Display Pipeline) which is an entry point for graphic (RGB) buffers - VDP (Video Diplay Pipeline) which is an entry point for video (YUV) buffers - HQVDP (High Quality Video Display Processor) that supports scaling, deinterlacing and some miscellaneous image quality improvements. It fetches the Video decoded buffers from memory, processes them and pushes them to the Compositor through a HW dedicated bus. - Mixer is responsible of mixing all the entries depending of their respective z-order and layout TVout is divided in 3 parts: - HDMI to generate HDMI signals, depending of chipset version HDMI phy can change. - HDA to generate signals for HD analog TV - VIP to control/switch data path coming from Compositor On stih416 compositor and Tvout are on different dies so a Video Trafic Advance inter-die Communication mechanism (VTAC) is needed. +---------------------------------------------+ +----------------------------------------+ | +-------------------------------+ +----+ | | +----+ +--------------------------+ | | | | | | | | | | | +---------+ +----+ | | | | +----+ +------+ | | | | | | | | | VIP |---->|HDMI| | | | | |GPD +------------->| | | | | | | | | | | | +----+ | | | | +----+ |Mixer |--|-->| | | | | |---|->| switcher| | | | | | | | | | | | | | | | | +----+ | | | | | | | | | | | | | | | |---->|HDA | | | | | +------+ | |VTAC|========>|VTAC| | +---------+ +----+ | | | | | | | | | | | | | | | | Compositor | | | | | | | | TVout | | | +-------------------------------+ | | | | | | +--------------------------+ | | ^ | | | | | | ^ | | | | | | | | | | | | +--------------+ | | | | | | +-------------+ | | | VTG (master) |----->| | | | | |----->| VTG (slave) | | | +--------------+ +----+ | | +----+ +-------------+ | |Digital die | | Analog Die| +---------------------------------------------+ +----------------------------------------+ On stih407 Compositor and Tvout are on the same die +-----------------------------------------------------------------+ | +-------------------------------+ +--------------------------+ | | | | | +---------+ +----+ | | | | +----+ +------+ | | | VIP |---->|HDMI| | | | | |GPD +------------->| | | | | | +----+ | | | | +----+ |Mixer |--|--|->| switcher| | | | | +----+ +-----+ | | | | | | +----+ | | | | |VDP +-->+HQVDP+--->| | | | | |---->|HDA | | | | | +----+ +-----+ +------+ | | +---------+ +----+ | | | | | | | | | | Compositor | | TVout | | | +-------------------------------+ +--------------------------+ | | ^ ^ | | | | | | +--------------+ | | | VTG | | | +--------------+ | |Digital die | +-----------------------------------------------------------------+ In addition of the drivers for the IPs listed before a thin I2C driver (hdmiddc) is used by HDMI driver to retrieve EDID for monitor. To unify interfaces of GDP and VDP we create a "layer" interface called by compositor to control both GPD and VDP. Hardware have memory contraints (alignment, contiguous) so we use CMA drm helpers functions to allocate frame buffer. File naming convention is: - sti_* for IPs drivers - sti_drm_* for drm functions implementation. Benjamin Gaignard (18): drm: sti: add bindings for DRM driver drm: sti: add VTG driver drm: sti: add VTAC drivers drm: sti: add HDMI driver drm: sti: add I2C client driver for HDMI drm: sti: add HDA driver drm: sti: add TVOut driver drm: sti: add sti layer interface definition drm: sti: add GDP layer drm: sti: add VID layer drm: sti: add Mixer drm: sti: add Compositor drm: sti: add debug to GDP drm: sti: add debug to VID drm: sti: add debug to TVout drm: sti: add debug to mixer drm: sti: Add DRM driver itself drm: sti: add HQVDP driver Vincent Abriou (1): drm: sti: rename mixer registers to be main/aux independent .../devicetree/bindings/gpu/st,stih4xx.txt | 177 ++++ drivers/gpu/drm/Kconfig | 2 + drivers/gpu/drm/Makefile | 1 + drivers/gpu/drm/sti/Kconfig | 26 + drivers/gpu/drm/sti/Makefile | 23 + drivers/gpu/drm/sti/sti_compositor.c | 189 ++++ drivers/gpu/drm/sti/sti_compositor.h | 84 ++ drivers/gpu/drm/sti/sti_ddc.c | 56 + drivers/gpu/drm/sti/sti_drm_connector.c | 195 ++++ drivers/gpu/drm/sti/sti_drm_connector.h | 16 + drivers/gpu/drm/sti/sti_drm_crtc.c | 440 ++++++++ drivers/gpu/drm/sti/sti_drm_crtc.h | 21 + drivers/gpu/drm/sti/sti_drm_drv.c | 484 +++++++++ drivers/gpu/drm/sti/sti_drm_drv.h | 48 + drivers/gpu/drm/sti/sti_drm_encoder.c | 201 ++++ drivers/gpu/drm/sti/sti_drm_encoder.h | 16 + drivers/gpu/drm/sti/sti_drm_plane.c | 195 ++++ drivers/gpu/drm/sti/sti_drm_plane.h | 16 + drivers/gpu/drm/sti/sti_gdp.c | 726 +++++++++++++ drivers/gpu/drm/sti/sti_gdp.h | 75 ++ drivers/gpu/drm/sti/sti_hda.c | 826 +++++++++++++++ drivers/gpu/drm/sti/sti_hda.h | 14 + drivers/gpu/drm/sti/sti_hdmi.c | 1045 +++++++++++++++++++ drivers/gpu/drm/sti/sti_hdmi.h | 198 ++++ drivers/gpu/drm/sti/sti_hdmi_tx3g0c55phy.c | 398 +++++++ drivers/gpu/drm/sti/sti_hdmi_tx3g4c28phy.c | 224 ++++ drivers/gpu/drm/sti/sti_hqvdp.c | 1089 ++++++++++++++++++++ drivers/gpu/drm/sti/sti_hqvdp.h | 55 + drivers/gpu/drm/sti/sti_hqvdp_lut.h | 373 +++++++ drivers/gpu/drm/sti/sti_layer.c | 324 ++++++ drivers/gpu/drm/sti/sti_layer.h | 116 +++ drivers/gpu/drm/sti/sti_mixer.c | 405 ++++++++ drivers/gpu/drm/sti/sti_mixer.h | 54 + drivers/gpu/drm/sti/sti_tvout.c | 863 ++++++++++++++++ drivers/gpu/drm/sti/sti_tvout.h | 105 ++ drivers/gpu/drm/sti/sti_vid.c | 259 +++++ drivers/gpu/drm/sti/sti_vid.h | 34 + drivers/gpu/drm/sti/sti_vtac_rx.c | 140 +++ drivers/gpu/drm/sti/sti_vtac_tx.c | 152 +++ drivers/gpu/drm/sti/sti_vtac_utils.h | 52 + drivers/gpu/drm/sti/sti_vtg.c | 438 ++++++++ drivers/gpu/drm/sti/sti_vtg.h | 20 + drivers/gpu/drm/sti/sti_vtg_utils.c | 99 ++ drivers/gpu/drm/sti/sti_vtg_utils.h | 29 + 44 files changed, 10303 insertions(+) create mode 100644 Documentation/devicetree/bindings/gpu/st,stih4xx.txt create mode 100644 drivers/gpu/drm/sti/Kconfig create mode 100644 drivers/gpu/drm/sti/Makefile create mode 100644 drivers/gpu/drm/sti/sti_compositor.c create mode 100644 drivers/gpu/drm/sti/sti_compositor.h create mode 100644 drivers/gpu/drm/sti/sti_ddc.c create mode 100644 drivers/gpu/drm/sti/sti_drm_connector.c create mode 100644 drivers/gpu/drm/sti/sti_drm_connector.h create mode 100644 drivers/gpu/drm/sti/sti_drm_crtc.c create mode 100644 drivers/gpu/drm/sti/sti_drm_crtc.h create mode 100644 drivers/gpu/drm/sti/sti_drm_drv.c create mode 100644 drivers/gpu/drm/sti/sti_drm_drv.h create mode 100644 drivers/gpu/drm/sti/sti_drm_encoder.c create mode 100644 drivers/gpu/drm/sti/sti_drm_encoder.h create mode 100644 drivers/gpu/drm/sti/sti_drm_plane.c create mode 100644 drivers/gpu/drm/sti/sti_drm_plane.h create mode 100644 drivers/gpu/drm/sti/sti_gdp.c create mode 100644 drivers/gpu/drm/sti/sti_gdp.h create mode 100644 drivers/gpu/drm/sti/sti_hda.c create mode 100644 drivers/gpu/drm/sti/sti_hda.h create mode 100644 drivers/gpu/drm/sti/sti_hdmi.c create mode 100644 drivers/gpu/drm/sti/sti_hdmi.h create mode 100644 drivers/gpu/drm/sti/sti_hdmi_tx3g0c55phy.c create mode 100644 drivers/gpu/drm/sti/sti_hdmi_tx3g4c28phy.c create mode 100644 drivers/gpu/drm/sti/sti_hqvdp.c create mode 100644 drivers/gpu/drm/sti/sti_hqvdp.h create mode 100644 drivers/gpu/drm/sti/sti_hqvdp_lut.h create mode 100644 drivers/gpu/drm/sti/sti_layer.c create mode 100644 drivers/gpu/drm/sti/sti_layer.h create mode 100644 drivers/gpu/drm/sti/sti_mixer.c create mode 100644 drivers/gpu/drm/sti/sti_mixer.h create mode 100644 drivers/gpu/drm/sti/sti_tvout.c create mode 100644 drivers/gpu/drm/sti/sti_tvout.h create mode 100644 drivers/gpu/drm/sti/sti_vid.c create mode 100644 drivers/gpu/drm/sti/sti_vid.h create mode 100644 drivers/gpu/drm/sti/sti_vtac_rx.c create mode 100644 drivers/gpu/drm/sti/sti_vtac_tx.c create mode 100644 drivers/gpu/drm/sti/sti_vtac_utils.h create mode 100644 drivers/gpu/drm/sti/sti_vtg.c create mode 100644 drivers/gpu/drm/sti/sti_vtg.h create mode 100644 drivers/gpu/drm/sti/sti_vtg_utils.c create mode 100644 drivers/gpu/drm/sti/sti_vtg_utils.h -- 1.9.0

9 years, 11 months

mem-hotplug: Can arm receive memory-hotplug feature from x86 platform

by xiaofeng.yan

Hi all, I found some scenario could need memory-hotplug feature in their product based on platform ARM. A typical scenario can be described as follows: Developer reserve some memory which can't be accessed by kernel and other function can use these memory before system start up. After booting, system can reclaim the memory reserved with memory-hot plug mechanism. for example , user can add the reserved memory by the next command. #echo "PHYSICAL_ADDRESS_OF_MEMORY, SIZE_FOR_ADDING_MEMORY" > /kernel/sys/addmemory/addmemory. PHYSICAL_ADDRESS_OF_MEMORY: the begging position for adding memory SIZE_FOR_ADDING_MEMORY: the memory size you want to add. the unit should be integral multiple of a section size. So my question is whether arm support memory-hot plug or not in next plan. I am very interested to move the feature from x86 to arm. I have finish the above function and realize dynamic memory addition. I can push my patches if possible. Give me your suggestion. Thanks xiaofeng.yan

9 years, 12 months

Re: [Linaro-mm-sig] [RFC] Helper to abstract vma handling in media layer

by Hans Verkuil

On 04/11/2014 12:18 AM, Jan Kara wrote: > On Thu 10-04-14 23:57:38, Jan Kara wrote: >> On Thu 10-04-14 14:22:20, Hans Verkuil wrote: >>> On 04/10/14 14:15, Jan Kara wrote: >>>> On Thu 10-04-14 13:07:42, Hans Verkuil wrote: >>>>> On 04/10/14 12:32, Jan Kara wrote: >>>>>> Hello, >>>>>> >>>>>> On Thu 10-04-14 12:02:50, Marek Szyprowski wrote: >>>>>>> On 2014-03-17 20:49, Jan Kara wrote: >>>>>>>> The following patch series is my first stab at abstracting vma handling >>>>>>> >from the various media drivers. After this patch set drivers have to know >>>>>>>> much less details about vmas, their types, and locking. My motivation for >>>>>>>> the series is that I want to change get_user_pages() locking and I want >>>>>>>> to handle subtle locking details in as few places as possible. >>>>>>>> >>>>>>>> The core of the series is the new helper get_vaddr_pfns() which is given a >>>>>>>> virtual address and it fills in PFNs into provided array. If PFNs correspond to >>>>>>>> normal pages it also grabs references to these pages. The difference from >>>>>>>> get_user_pages() is that this function can also deal with pfnmap, mixed, and io >>>>>>>> mappings which is what the media drivers need. >>>>>>>> >>>>>>>> The patches are just compile tested (since I don't have any of the hardware >>>>>>>> I'm afraid I won't be able to do any more testing anyway) so please handle >>>>>>>> with care. I'm grateful for any comments. >>>>>>> >>>>>>> Thanks for posting this series! I will check if it works with our >>>>>>> hardware soon. This is something I wanted to introduce some time ago to >>>>>>> simplify buffer handling in dma-buf, but I had no time to start working. >>>>>> Thanks for having a look in the series. >>>>>> >>>>>>> However I would like to go even further with integration of your pfn >>>>>>> vector idea. This structure looks like a best solution for a compact >>>>>>> representation of the memory buffer, which should be considered by the >>>>>>> hardware as contiguous (either contiguous in physical memory or mapped >>>>>>> contiguously into dma address space by the respective iommu). As you >>>>>>> already noticed it is widely used by graphics and video drivers. >>>>>>> >>>>>>> I would also like to add support for pfn vector directly to the >>>>>>> dma-mapping subsystem. This can be done quite easily (even with a >>>>>>> fallback for architectures which don't provide method for it). I will try >>>>>>> to prepare rfc soon. This will finally remove the need for hacks in >>>>>>> media/v4l2-core/videobuf2-dma-contig.c >>>>>> That would be a worthwhile thing to do. When I was reading the code this >>>>>> seemed like something which could be done but I delibrately avoided doing >>>>>> more unification than necessary for my purposes as I don't have any >>>>>> hardware to test and don't know all the subtleties in the code... BTW, is >>>>>> there some way to test the drivers without the physical video HW? >>>>> >>>>> You can use the vivi driver (drivers/media/platform/vivi) for this. >>>>> However, while the vivi driver can import dma buffers it cannot export >>>>> them. If you want that, then you have to use this tree: >>>>> >>>>> http://git.linuxtv.org/cgit.cgi/hverkuil/media_tree.git/log/?h=vb2-part4 >>>> Thanks for the pointer that looks good. I've also found >>>> drivers/media/platform/mem2mem_testdev.c which seems to do even more >>>> testing of the area I made changes to. So now I have to find some userspace >>>> tool which can issue proper ioctls to setup and use the buffers and I can >>>> start testing what I wrote :) >>> >>> Get the v4l-utils.git repository (http://git.linuxtv.org/cgit.cgi/v4l-utils.git/). >>> You want the v4l2-ctl tool. Don't use the version supplied by your distro, >>> that's often too old. >>> >>> 'v4l2-ctl --help-streaming' gives the available options for doing streaming. >>> >>> So simple capturing from vivi is 'v4l2-ctl --stream-mmap' or '--stream-user'. >>> You can't test dmabuf unless you switch to the vb2-part4 branch of my tree. >> Great, it seems to be doing something and it shows there's some bug in my >> code. Thanks a lot for help. > OK, so after a small fix the basic functionality seems to be working. It > doesn't seem there's a way to test multiplanar buffers with vivi, is there? For that you need to switch to the vb2-part4 branch as well. That has support for multiplanar. Regards, Hans

10 years

Re: [Linaro-mm-sig] [RFC] Helper to abstract vma handling in media layer

by Hans Verkuil

On 04/10/14 14:15, Jan Kara wrote: > On Thu 10-04-14 13:07:42, Hans Verkuil wrote: >> On 04/10/14 12:32, Jan Kara wrote: >>> Hello, >>> >>> On Thu 10-04-14 12:02:50, Marek Szyprowski wrote: >>>> On 2014-03-17 20:49, Jan Kara wrote: >>>>> The following patch series is my first stab at abstracting vma handling >>>> >from the various media drivers. After this patch set drivers have to know >>>>> much less details about vmas, their types, and locking. My motivation for >>>>> the series is that I want to change get_user_pages() locking and I want >>>>> to handle subtle locking details in as few places as possible. >>>>> >>>>> The core of the series is the new helper get_vaddr_pfns() which is given a >>>>> virtual address and it fills in PFNs into provided array. If PFNs correspond to >>>>> normal pages it also grabs references to these pages. The difference from >>>>> get_user_pages() is that this function can also deal with pfnmap, mixed, and io >>>>> mappings which is what the media drivers need. >>>>> >>>>> The patches are just compile tested (since I don't have any of the hardware >>>>> I'm afraid I won't be able to do any more testing anyway) so please handle >>>>> with care. I'm grateful for any comments. >>>> >>>> Thanks for posting this series! I will check if it works with our >>>> hardware soon. This is something I wanted to introduce some time ago to >>>> simplify buffer handling in dma-buf, but I had no time to start working. >>> Thanks for having a look in the series. >>> >>>> However I would like to go even further with integration of your pfn >>>> vector idea. This structure looks like a best solution for a compact >>>> representation of the memory buffer, which should be considered by the >>>> hardware as contiguous (either contiguous in physical memory or mapped >>>> contiguously into dma address space by the respective iommu). As you >>>> already noticed it is widely used by graphics and video drivers. >>>> >>>> I would also like to add support for pfn vector directly to the >>>> dma-mapping subsystem. This can be done quite easily (even with a >>>> fallback for architectures which don't provide method for it). I will try >>>> to prepare rfc soon. This will finally remove the need for hacks in >>>> media/v4l2-core/videobuf2-dma-contig.c >>> That would be a worthwhile thing to do. When I was reading the code this >>> seemed like something which could be done but I delibrately avoided doing >>> more unification than necessary for my purposes as I don't have any >>> hardware to test and don't know all the subtleties in the code... BTW, is >>> there some way to test the drivers without the physical video HW? >> >> You can use the vivi driver (drivers/media/platform/vivi) for this. >> However, while the vivi driver can import dma buffers it cannot export >> them. If you want that, then you have to use this tree: >> >> http://git.linuxtv.org/cgit.cgi/hverkuil/media_tree.git/log/?h=vb2-part4 > Thanks for the pointer that looks good. I've also found > drivers/media/platform/mem2mem_testdev.c which seems to do even more > testing of the area I made changes to. So now I have to find some userspace > tool which can issue proper ioctls to setup and use the buffers and I can > start testing what I wrote :) Get the v4l-utils.git repository (http://git.linuxtv.org/cgit.cgi/v4l-utils.git/). You want the v4l2-ctl tool. Don't use the version supplied by your distro, that's often too old. 'v4l2-ctl --help-streaming' gives the available options for doing streaming. So simple capturing from vivi is 'v4l2-ctl --stream-mmap' or '--stream-user'. You can't test dmabuf unless you switch to the vb2-part4 branch of my tree. If you need help with testing it's easiest to contact me on the #v4l irc channel. Regards, Hans

10 years

Re: [Linaro-mm-sig] [RFC] Helper to abstract vma handling in media layer

by Hans Verkuil

On 04/10/14 12:32, Jan Kara wrote: > Hello, > > On Thu 10-04-14 12:02:50, Marek Szyprowski wrote: >> On 2014-03-17 20:49, Jan Kara wrote: >>> The following patch series is my first stab at abstracting vma handling >> >from the various media drivers. After this patch set drivers have to know >>> much less details about vmas, their types, and locking. My motivation for >>> the series is that I want to change get_user_pages() locking and I want >>> to handle subtle locking details in as few places as possible. >>> >>> The core of the series is the new helper get_vaddr_pfns() which is given a >>> virtual address and it fills in PFNs into provided array. If PFNs correspond to >>> normal pages it also grabs references to these pages. The difference from >>> get_user_pages() is that this function can also deal with pfnmap, mixed, and io >>> mappings which is what the media drivers need. >>> >>> The patches are just compile tested (since I don't have any of the hardware >>> I'm afraid I won't be able to do any more testing anyway) so please handle >>> with care. I'm grateful for any comments. >> >> Thanks for posting this series! I will check if it works with our >> hardware soon. This is something I wanted to introduce some time ago to >> simplify buffer handling in dma-buf, but I had no time to start working. > Thanks for having a look in the series. > >> However I would like to go even further with integration of your pfn >> vector idea. This structure looks like a best solution for a compact >> representation of the memory buffer, which should be considered by the >> hardware as contiguous (either contiguous in physical memory or mapped >> contiguously into dma address space by the respective iommu). As you >> already noticed it is widely used by graphics and video drivers. >> >> I would also like to add support for pfn vector directly to the >> dma-mapping subsystem. This can be done quite easily (even with a >> fallback for architectures which don't provide method for it). I will try >> to prepare rfc soon. This will finally remove the need for hacks in >> media/v4l2-core/videobuf2-dma-contig.c > That would be a worthwhile thing to do. When I was reading the code this > seemed like something which could be done but I delibrately avoided doing > more unification than necessary for my purposes as I don't have any > hardware to test and don't know all the subtleties in the code... BTW, is > there some way to test the drivers without the physical video HW? You can use the vivi driver (drivers/media/platform/vivi) for this. However, while the vivi driver can import dma buffers it cannot export them. If you want that, then you have to use this tree: http://git.linuxtv.org/cgit.cgi/hverkuil/media_tree.git/log/?h=vb2-part4 Regards, Hans

10 years

Re: [Linaro-mm-sig] [RFC] Helper to abstract vma handling in media layer

by Marek Szyprowski

Hello, On 2014-03-17 20:49, Jan Kara wrote: > The following patch series is my first stab at abstracting vma handling > from the various media drivers. After this patch set drivers have to know > much less details about vmas, their types, and locking. My motivation for > the series is that I want to change get_user_pages() locking and I want > to handle subtle locking details in as few places as possible. > > The core of the series is the new helper get_vaddr_pfns() which is given a > virtual address and it fills in PFNs into provided array. If PFNs correspond to > normal pages it also grabs references to these pages. The difference from > get_user_pages() is that this function can also deal with pfnmap, mixed, and io > mappings which is what the media drivers need. > > The patches are just compile tested (since I don't have any of the hardware > I'm afraid I won't be able to do any more testing anyway) so please handle > with care. I'm grateful for any comments. Thanks for posting this series! I will check if it works with our hardware soon. This is something I wanted to introduce some time ago to simplify buffer handling in dma-buf, but I had no time to start working. However I would like to go even further with integration of your pfn vector idea. This structure looks like a best solution for a compact representation of the memory buffer, which should be considered by the hardware as contiguous (either contiguous in physical memory or mapped contiguously into dma address space by the respective iommu). As you already noticed it is widely used by graphics and video drivers. I would also like to add support for pfn vector directly to the dma-mapping subsystem. This can be done quite easily (even with a fallback for architectures which don't provide method for it). I will try to prepare rfc soon. This will finally remove the need for hacks in media/v4l2-core/videobuf2-dma-contig.c Thanks for motivating me to finally start working on this! Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland

10 years

Re: [Linaro-mm-sig] [PATCH 2/2] dma-buf: update exp_name when using dma_buf_export()

by Daniel Vetter

On Thu, Apr 10, 2014 at 01:30:06AM +0200, Javier Martinez Canillas wrote: > commit c0b00a5 ("dma-buf: update debugfs output") modified the > default exporter name to be the KBUILD_MODNAME pre-processor > macro instead of __FILE__ but the documentation was not updated. > > Also the "Supporting existing mmap interfaces in exporters" section > title seems wrong since talks about the interface used by importers. > > Signed-off-by: Javier Martinez Canillas <javier.martinez(a)collabora.co.uk> Reviewed-by: Daniel Vetter <daniel.vetter(a)ffwll.ch> > --- > Documentation/dma-buf-sharing.txt | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/Documentation/dma-buf-sharing.txt b/Documentation/dma-buf-sharing.txt > index 505e711..7d61cef 100644 > --- a/Documentation/dma-buf-sharing.txt > +++ b/Documentation/dma-buf-sharing.txt > @@ -66,7 +66,7 @@ The dma_buf buffer sharing API usage contains the following steps: > > Exporting modules which do not wish to provide any specific name may use the > helper define 'dma_buf_export()', with the same arguments as above, but > - without the last argument; a __FILE__ pre-processor directive will be > + without the last argument; a KBUILD_MODNAME pre-processor directive will be > inserted in place of 'exp_name' instead. > > 2. Userspace gets a handle to pass around to potential buffer-users > @@ -352,7 +352,7 @@ Being able to mmap an export dma-buf buffer object has 2 main use-cases: > > No special interfaces, userspace simply calls mmap on the dma-buf fd. > > -2. Supporting existing mmap interfaces in exporters > +2. Supporting existing mmap interfaces in importers > > Similar to the motivation for kernel cpu access it is again important that > the userspace code of a given importing subsystem can use the same interfaces > -- > 1.9.0 > > _______________________________________________ > dri-devel mailing list > dri-devel(a)lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/dri-devel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch

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Linaro-mm-sig April 2014