#
3d1ff9df |
|
22-Nov-2023 |
Ramesh Errabolu <Ramesh.Errabolu@amd.com> |
dma-buf: Correct the documentation of name and exp_name symbols Fix the documentation of struct dma_buf members name and exp_name as to how these members are to be used and accessed. Signed-off-by: Ramesh Errabolu <Ramesh.Errabolu@amd.com> Reviewed-by: Christian König <christian.koenig@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20231122160556.24948-1-Ramesh.Errabolu@amd.com Signed-off-by: Christian König <christian.koenig@amd.com>
|
#
b56ffa58 |
|
23-Nov-2022 |
T.J. Mercier <tjmercier@google.com> |
dma-buf: A collection of typo and documentation fixes I've been collecting these typo fixes for a while and it feels like time to send them in. Signed-off-by: T.J. Mercier <tjmercier@google.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Christian König <christian.koenig@amd.com> Reviewed-by: Tommaso Merciai <tommaso.merciai@amarulasolutions.com> Link: https://patchwork.freedesktop.org/patch/msgid/20221123193519.3948105-1-tjmercier@google.com Signed-off-by: Christian König <christian.koenig@amd.com>
|
#
28743e25 |
|
17-Oct-2022 |
Dmitry Osipenko <dmitry.osipenko@collabora.com> |
dma-buf: Remove obsoleted internal lock The internal dma-buf lock isn't needed anymore because the updated locking specification claims that dma-buf reservation must be locked by importers, and thus, the internal data is already protected by the reservation lock. Remove the obsoleted internal lock. Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Christian König <christian.koenig@amd.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Link: https://patchwork.freedesktop.org/patch/msgid/20221017172229.42269-22-dmitry.osipenko@collabora.com
|
#
19d6634d |
|
17-Oct-2022 |
Dmitry Osipenko <dmitry.osipenko@collabora.com> |
dma-buf: Add unlocked variant of attachment-mapping functions Add unlocked variant of dma_buf_map/unmap_attachment() that will be used by drivers that don't take the reservation lock explicitly. Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Link: https://patchwork.freedesktop.org/patch/msgid/20221017172229.42269-3-dmitry.osipenko@collabora.com
|
#
56e5abba |
|
17-Oct-2022 |
Dmitry Osipenko <dmitry.osipenko@collabora.com> |
dma-buf: Add unlocked variant of vmapping functions Add unlocked variant of dma_buf_vmap/vunmap() that will be utilized by drivers that don't take the reservation lock explicitly. Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Link: https://patchwork.freedesktop.org/patch/msgid/20221017172229.42269-2-dmitry.osipenko@collabora.com
|
#
73511edf |
|
09-Nov-2021 |
Christian König <christian.koenig@amd.com> |
dma-buf: specify usage while adding fences to dma_resv obj v7 Instead of distingting between shared and exclusive fences specify the fence usage while adding fences. Rework all drivers to use this interface instead and deprecate the old one. v2: some kerneldoc comments suggested by Daniel v3: fix a missing case in radeon v4: rebase on nouveau changes, fix lockdep and temporary disable warning v5: more documentation updates v6: separate internal dma_resv changes from this patch, avoids to disable warning temporary, rebase on upstream changes v7: fix missed case in lima driver, minimize changes to i915_gem_busy_ioctl Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20220407085946.744568-3-christian.koenig@amd.com
|
#
7bc80a54 |
|
09-Nov-2021 |
Christian König <christian.koenig@amd.com> |
dma-buf: add enum dma_resv_usage v4 This change adds the dma_resv_usage enum and allows us to specify why a dma_resv object is queried for its containing fences. Additional to that a dma_resv_usage_rw() helper function is added to aid retrieving the fences for a read or write userspace submission. This is then deployed to the different query functions of the dma_resv object and all of their users. When the write paratermer was previously true we now use DMA_RESV_USAGE_WRITE and DMA_RESV_USAGE_READ otherwise. v2: add KERNEL/OTHER in separate patch v3: some kerneldoc suggestions by Daniel v4: some more kerneldoc suggestions by Daniel, fix missing cases lost in the rebase pointed out by Bas. Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20220407085946.744568-2-christian.koenig@amd.com
|
#
15325e3c |
|
11-Nov-2021 |
Christian König <christian.koenig@amd.com> |
dma-buf: drop the DAG approach for the dma_resv object v3 So far we had the approach of using a directed acyclic graph with the dma_resv obj. This turned out to have many downsides, especially it means that every single driver and user of this interface needs to be aware of this restriction when adding fences. If the rules for the DAG are not followed then we end up with potential hard to debug memory corruption, information leaks or even elephant big security holes because we allow userspace to access freed up memory. Since we already took a step back from that by always looking at all fences we now go a step further and stop dropping the shared fences when a new exclusive one is added. v2: Drop some now superflous documentation v3: Add some more documentation for the new handling. Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20220321135856.1331-11-christian.koenig@amd.com
|
#
7938f421 |
|
04-Feb-2022 |
Lucas De Marchi <lucas.demarchi@intel.com> |
dma-buf-map: Rename to iosys-map 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
|
#
dd66f56c |
|
21-Oct-2021 |
Christian König <christian.koenig@amd.com> |
dma-buf: fix kerneldoc for renamed members Those members where renamed, update the kerneldoc as well. Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20211021141945.84023-1-christian.koenig@amd.com
|
#
5460601d |
|
12-Oct-2021 |
Gal Pressman <galpress@amazon.com> |
dma-buf: Fix pin callback comment The pin callback does not necessarily have to move the memory to system memory, remove the sentence from the comment. Link: https://lore.kernel.org/r/20211012120903.96933-2-galpress@amazon.com Signed-off-by: Gal Pressman <galpress@amazon.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
|
#
6b51b02a |
|
15-Jun-2021 |
Christian König <christian.koenig@amd.com> |
dma-buf: fix and rework dma_buf_poll v7 Daniel pointed me towards this function and there are multiple obvious problems in the implementation. First of all the retry loop is not working as intended. In general the retry makes only sense if you grab the reference first and then check the sequence values. Then we should always also wait for the exclusive fence. It's also good practice to keep the reference around when installing callbacks to fences you don't own. And last the whole implementation was unnecessary complex and rather hard to understand which could lead to probably unexpected behavior of the IOCTL. Fix all this by reworking the implementation from scratch. Dropping the whole RCU approach and taking the lock instead. Only mildly tested and needs a thoughtful review of the code. Pushing through drm-misc-next to avoid merge conflicts and give the code another round of testing. v2: fix the reference counting as well v3: keep the excl fence handling as is for stable v4: back to testing all fences, drop RCU v5: handle in and out separately v6: add missing clear of events v7: change coding style as suggested by Michel, drop unused variables Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Tested-by: Michel Dänzer <mdaenzer@redhat.com> CC: stable@vger.kernel.org Link: https://patchwork.freedesktop.org/patch/msgid/20210720131110.88512-1-christian.koenig@amd.com
|
#
d9edf92d |
|
04-Aug-2021 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
dma-resv: Give the docs a do-over Specifically document the new/clarified rules around how the shared fences do not have any ordering requirements against the exclusive fence. But also document all the things a bit better, given how central struct dma_resv to dynamic buffer management the docs have been very inadequat. - Lots more links to other pieces of the puzzle. Unfortunately ttm_buffer_object has no docs, so no links :-( - Explain/complain a bit about dma_resv_locking_ctx(). I still don't like that one, but fixing the ttm call chains is going to be horrible. Plus we want to plug in real slowpath locking when we do that anyway. - Main part of the patch is some actual docs for struct dma_resv. Overall I think we still have a lot of bad naming in this area (e.g. dma_resv.fence is singular, but contains the multiple shared fences), but I think that's more indicative of how the semantics and rules are just not great. Another thing that's real awkard is how chaining exclusive fences right now means direct dma_resv.exclusive_fence pointer access with an rcu_assign_pointer. Not so great either. v2: - Fix a pile of typos (Matt, Jason) - Hammer it in that breaking the rules leads to use-after-free issues around dma-buf sharing (Christian) Reviewed-by: Christian König <christian.koenig@amd.com> Cc: Jason Ekstrand <jason@jlekstrand.net> Cc: Matthew Auld <matthew.auld@intel.com> Reviewed-by: Matthew Auld <matthew.auld@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: "Christian König" <christian.koenig@amd.com> Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Link: https://patchwork.freedesktop.org/patch/msgid/20210805104705.862416-21-daniel.vetter@ffwll.ch
|
#
a4812d0b |
|
09-Aug-2021 |
Gal Pressman <galpress@amazon.com> |
dma-buf: Fix a few typos in dma-buf documentation Fix a few typos in the documentation: - Remove an extraneous 'or' - 'unpins' -> 'unpin' - 'braket' -> 'bracket' - 'mappinsg' -> 'mappings' - 'fullfills' -> 'fulfills' Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Gal Pressman <galpress@amazon.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20210809122247.15869-1-galpress@amazon.com
|
#
c715def5 |
|
12-Jul-2021 |
Hridya Valsaraju <hridya@google.com> |
dma-buf: Delete the DMA-BUF attachment sysfs statistics The DMA-BUF attachment statistics form a subset of the DMA-BUF sysfs statistics that recently merged to the drm-misc tree. They are not UABI yet since they have not merged to the upstream Linux kernel. Since there has been a reported a performance regression due to the overhead of sysfs directory creation/teardown during dma_buf_attach()/dma_buf_detach(), this patch deletes the DMA-BUF attachment statistics from sysfs. Fixes: bdb8d06dfefd ("dmabuf: Add the capability to expose DMA-BUF stats in sysfs") Signed-off-by: Hridya Valsaraju <hridya@google.com> Reviewed-by: Christian König <christian.koenig@amd.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://patchwork.freedesktop.org/patch/msgid/20210713040742.2680135-1-hridya@google.com Signed-off-by: Christian König <christian.koenig@amd.com>
|
#
05459351 |
|
24-Jun-2021 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
dma-buf: Document dma-buf implicit fencing/resv fencing rules Docs for struct dma_resv are fairly clear: "A reservation object can have attached one exclusive fence (normally associated with write operations) or N shared fences (read operations)." https://dri.freedesktop.org/docs/drm/driver-api/dma-buf.html#reservation-objects Furthermore a review across all of upstream. First of render drivers and how they set implicit fences: - nouveau follows this contract, see in validate_fini_no_ticket() nouveau_bo_fence(nvbo, fence, !!b->write_domains); and that last boolean controls whether the exclusive or shared fence slot is used. - radeon follows this contract by setting p->relocs[i].tv.num_shared = !r->write_domain; in radeon_cs_parser_relocs(), which ensures that the call to ttm_eu_fence_buffer_objects() in radeon_cs_parser_fini() will do the right thing. - vmwgfx seems to follow this contract with the shotgun approach of always setting ttm_val_buf->num_shared = 0, which means ttm_eu_fence_buffer_objects() will only use the exclusive slot. - etnaviv follows this contract, as can be trivially seen by looking at submit_attach_object_fences() - i915 is a bit a convoluted maze with multiple paths leading to i915_vma_move_to_active(). Which sets the exclusive flag if EXEC_OBJECT_WRITE is set. This can either come as a buffer flag for softpin mode, or through the write_domain when using relocations. It follows this contract. - lima follows this contract, see lima_gem_submit() which sets the exclusive fence when the LIMA_SUBMIT_BO_WRITE flag is set for that bo - msm follows this contract, see msm_gpu_submit() which sets the exclusive flag when the MSM_SUBMIT_BO_WRITE is set for that buffer - panfrost follows this contract with the shotgun approach of just always setting the exclusive fence, see panfrost_attach_object_fences(). Benefits of a single engine I guess - v3d follows this contract with the same shotgun approach in v3d_attach_fences_and_unlock_reservation(), but it has at least an XXX comment that maybe this should be improved - v4c uses the same shotgun approach of always setting an exclusive fence, see vc4_update_bo_seqnos() - vgem also follows this contract, see vgem_fence_attach_ioctl() and the VGEM_FENCE_WRITE. This is used in some igts to validate prime sharing with i915.ko without the need of a 2nd gpu - vritio follows this contract again with the shotgun approach of always setting an exclusive fence, see virtio_gpu_array_add_fence() This covers the setting of the exclusive fences when writing. Synchronizing against the exclusive fence is a lot more tricky, and I only spot checked a few: - i915 does it, with the optional EXEC_OBJECT_ASYNC to skip all implicit dependencies (which is used by vulkan) - etnaviv does this. Implicit dependencies are collected in submit_fence_sync(), again with an opt-out flag ETNA_SUBMIT_NO_IMPLICIT. These are then picked up in etnaviv_sched_dependency which is the drm_sched_backend_ops->dependency callback. - v4c seems to not do much here, maybe gets away with it by not having a scheduler and only a single engine. Since all newer broadcom chips than the OG vc4 use v3d for rendering, which follows this contract, the impact of this issue is fairly small. - v3d does this using the drm_gem_fence_array_add_implicit() helper, which then it's drm_sched_backend_ops->dependency callback v3d_job_dependency() picks up. - panfrost is nice here and tracks the implicit fences in panfrost_job->implicit_fences, which again the drm_sched_backend_ops->dependency callback panfrost_job_dependency() picks up. It is mildly questionable though since it only picks up exclusive fences in panfrost_acquire_object_fences(), but not buggy in practice because it also always sets the exclusive fence. It should pick up both sets of fences, just in case there's ever going to be a 2nd gpu in a SoC with a mali gpu. Or maybe a mali SoC with a pcie port and a real gpu, which might actually happen eventually. A bug, but easy to fix. Should probably use the drm_gem_fence_array_add_implicit() helper. - lima is nice an easy, uses drm_gem_fence_array_add_implicit() and the same schema as v3d. - msm is mildly entertaining. It also supports MSM_SUBMIT_NO_IMPLICIT, but because it doesn't use the drm/scheduler it handles fences from the wrong context with a synchronous dma_fence_wait. See submit_fence_sync() leading to msm_gem_sync_object(). Investing into a scheduler might be a good idea. - all the remaining drivers are ttm based, where I hope they do appropriately obey implicit fences already. I didn't do the full audit there because a) not follow the contract would confuse ttm quite well and b) reading non-standard scheduler and submit code which isn't based on drm/scheduler is a pain. Onwards to the display side. - Any driver using the drm_gem_plane_helper_prepare_fb() helper will correctly. Overwhelmingly most drivers get this right, except a few totally dont. I'll follow up with a patch to make this the default and avoid a bunch of bugs. - I didn't audit the ttm drivers, but given that dma_resv started there I hope they get this right. In conclusion this IS the contract, both as documented and overwhelmingly implemented, specically as implemented by all render drivers except amdgpu. Amdgpu tried to fix this already in commit 049aca4363d8af87cab8d53de5401602db3b9999 Author: Christian König <christian.koenig@amd.com> Date: Wed Sep 19 16:54:35 2018 +0200 drm/amdgpu: fix using shared fence for exported BOs v2 but this fix falls short on a number of areas: - It's racy, by the time the buffer is shared it might be too late. To make sure there's definitely never a problem we need to set the fences correctly for any buffer that's potentially exportable. - It's breaking uapi, dma-buf fds support poll() and differentitiate between, which was introduced in commit 9b495a5887994a6d74d5c261d012083a92b94738 Author: Maarten Lankhorst <maarten.lankhorst@canonical.com> Date: Tue Jul 1 12:57:43 2014 +0200 dma-buf: add poll support, v3 - Christian König wants to nack new uapi building further on this dma_resv contract because it breaks amdgpu, quoting "Yeah, and that is exactly the reason why I will NAK this uAPI change. "This doesn't works for amdgpu at all for the reasons outlined above." https://lore.kernel.org/dri-devel/f2eb6751-2f82-9b23-f57e-548de5b729de@gmail.com/ Rejecting new development because your own driver is broken and violates established cross driver contracts and uapi is really not how upstream works. Now this patch will have a severe performance impact on anything that runs on multiple engines. So we can't just merge it outright, but need a bit a plan: - amdgpu needs a proper uapi for handling implicit fencing. The funny thing is that to do it correctly, implicit fencing must be treated as a very strange IPC mechanism for transporting fences, where both setting the fence and dependency intercepts must be handled explicitly. Current best practices is a per-bo flag to indicate writes, and a per-bo flag to to skip implicit fencing in the CS ioctl as a new chunk. - Since amdgpu has been shipping with broken behaviour we need an opt-out flag from the butchered implicit fencing model to enable the proper explicit implicit fencing model. - for kernel memory fences due to bo moves at least the i915 idea is to use ttm_bo->moving. amdgpu probably needs the same. - since the current p2p dma-buf interface assumes the kernel memory fence is in the exclusive dma_resv fence slot we need to add a new fence slot for kernel fences, which must never be ignored. Since currently only amdgpu supports this there's no real problem here yet, until amdgpu gains a NO_IMPLICIT CS flag. - New userspace needs to ship in enough desktop distros so that users wont notice the perf impact. I think we can ignore LTS distros who upgrade their kernels but not their mesa3d snapshot. - Then when this is all in place we can merge this patch here. What is not a solution to this problem here is trying to make the dma_resv rules in the kernel more clever. The fundamental issue here is that the amdgpu CS uapi is the least expressive one across all drivers (only equalled by panfrost, which has an actual excuse) by not allowing any userspace control over how implicit sync is conducted. Until this is fixed it's completely pointless to make the kernel more clever to improve amdgpu, because all we're doing is papering over this uapi design issue. amdgpu needs to attain the status quo established by other drivers first, once that's achieved we can tackle the remaining issues in a consistent way across drivers. v2: Bas pointed me at AMDGPU_GEM_CREATE_EXPLICIT_SYNC, which I entirely missed. This is great because it means the amdgpu specific piece for proper implicit fence handling exists already, and that since a while. The only thing that's now missing is - fishing the implicit fences out of a shared object at the right time - setting the exclusive implicit fence slot at the right time. Jason has a patch series to fill that gap with a bunch of generic ioctl on the dma-buf fd: https://lore.kernel.org/dri-devel/20210520190007.534046-1-jason@jlekstrand.net/ v3: Since Christian has fixed amdgpu now in commit 8c505bdc9c8b955223b054e34a0be9c3d841cd20 (drm-misc/drm-misc-next) Author: Christian König <christian.koenig@amd.com> Date: Wed Jun 9 13:51:36 2021 +0200 drm/amdgpu: rework dma_resv handling v3 Use the audit covered in this commit message as the excuse to update the dma-buf docs around dma_buf.resv usage across drivers. Since dynamic importers have different rules also hammer these in again while we're at it. v4: - Add the missing "through the device" in the dynamic section that I overlooked. - Fix a kerneldoc markup mistake, the link didn't connect v5: - A few s/should/must/ to make clear what must be done (if the driver does implicit sync) and what's more a maybe (Daniel Stone) - drop all the example api discussion, that needs to be expanded, clarified and put into a new chapter in drm-uapi.rst (Daniel Stone) Cc: Daniel Stone <daniel@fooishbar.org> Acked-by: Daniel Stone <daniel@fooishbar.org> Reviewed-by: Dave Airlie <airlied@redhat.com> (v4) Reviewed-by: Christian König <christian.koenig@amd.com> (v3) Cc: mesa-dev@lists.freedesktop.org Cc: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl> Cc: Dave Airlie <airlied@gmail.com> Cc: Rob Clark <robdclark@chromium.org> Cc: Kristian H. Kristensen <hoegsberg@google.com> Cc: Michel Dänzer <michel@daenzer.net> Cc: Daniel Stone <daniels@collabora.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: "Christian König" <christian.koenig@amd.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Deepak R Varma <mh12gx2825@gmail.com> Cc: Chen Li <chenli@uniontech.com> Cc: Kevin Wang <kevin1.wang@amd.com> Cc: Dennis Li <Dennis.Li@amd.com> Cc: Luben Tuikov <luben.tuikov@amd.com> Cc: linaro-mm-sig@lists.linaro.org Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210624125246.166721-1-daniel.vetter@ffwll.ch
|
#
d6abed2a |
|
23-Jun-2021 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
dma-buf: Switch to inline kerneldoc Also review & update everything while we're at it. This is prep work to smash a ton of stuff into the kerneldoc for @resv. v2: Move the doc for sysfs_entry.attachment_uid to the right place too (Sam) Reviewed-by: Sam Ravnborg <sam@ravnborg.org> Acked-by: Christian König <christian.koenig@amd.com> Cc: Sam Ravnborg <sam@ravnborg.org> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: "Christian König" <christian.koenig@amd.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dave Airlie <airlied@redhat.com> Cc: Nirmoy Das <nirmoy.das@amd.com> Cc: Deepak R Varma <mh12gx2825@gmail.com> Cc: Chen Li <chenli@uniontech.com> Cc: Kevin Wang <kevin1.wang@amd.com> Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Link: https://patchwork.freedesktop.org/patch/msgid/20210623161712.3370885-1-daniel.vetter@ffwll.ch
|
#
89bcadc8 |
|
21-Jun-2021 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
dma-buf: Document non-dynamic exporter expectations better Christian and me realized we have a pretty massive disconnect about different interpretations of what dma_resv is used for by different drivers. The discussion is much, much bigger than this change here, but this is an important one: Non-dynamic exporters must guarantee that the memory they return is ready for use. They cannot expect importers to wait for the exclusive fence. Only dynamic importers are required to obey the dma_resv fences strictly (and more patches are needed to define exactly what this means). Christian has patches to update nouvea, radeon and amdgpu. The only other driver using both ttm and supporting dma-buf export is qxl, which only uses synchronous ttm_bo_move. v2: To hammer this in document that dynamic importers _must_ wait for the exclusive fence after having called dma_buf_map_attachment. Reviewed-by: Christian König <christian.koenig@amd.com> Cc: Christian König <ckoenig.leichtzumerken@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210621151758.2347474-1-daniel.vetter@ffwll.ch
|
#
bdb8d06d |
|
03-Jun-2021 |
Hridya Valsaraju <hridya@google.com> |
dmabuf: Add the capability to expose DMA-BUF stats in sysfs Overview ======== The patch adds DMA-BUF statistics to /sys/kernel/dmabuf/buffers. It allows statistics to be enabled for each DMA-BUF in sysfs by enabling the config CONFIG_DMABUF_SYSFS_STATS. The following stats will be exposed by the interface: /sys/kernel/dmabuf/buffers/<inode_number>/exporter_name /sys/kernel/dmabuf/buffers/<inode_number>/size /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attach_uid>/device /sys/kernel/dmabuf/buffers/<inode_number>/attachments/<attach_uid>/map_counter The inode_number is unique for each DMA-BUF and was added earlier [1] in order to allow userspace to track DMA-BUF usage across different processes. Use Cases ========= The interface provides a way to gather DMA-BUF per-buffer statistics from production devices. These statistics will be used to derive DMA-BUF per-exporter stats and per-device usage stats for Android Bug reports. The corresponding userspace changes can be found at [2]. Telemetry tools will also capture this information(along with other memory metrics) periodically as well as on important events like a foreground app kill (which might have been triggered by Low Memory Killer). It will also contribute to provide a snapshot of the system memory usage on other events such as OOM kills and Application Not Responding events. Background ========== Currently, there are two existing interfaces that provide information about DMA-BUFs. 1) /sys/kernel/debug/dma_buf/bufinfo debugfs is however unsuitable to be mounted in production systems and cannot be considered as an alternative to the sysfs interface being proposed. 2) proc/<pid>/fdinfo/<fd> The proc/<pid>/fdinfo/<fd> files expose information about DMA-BUF fds. However, the existing procfs interfaces can only provide information about the buffers for which processes hold fds or have the buffers mmapped into their address space. Since the procfs interfaces alone cannot provide a full picture of all DMA-BUFs in the system, there is the need for an alternate interface to provide this information on production systems. The patch contains the following major improvements over v1: 1) Each attachment is represented by its own directory to allow creating a symlink to the importing device and to also provide room for future expansion. 2) The number of distinct mappings of each attachment is exposed in a separate file. 3) The per-buffer statistics are now in /sys/kernel/dmabuf/buffers inorder to make the interface expandable in future. All of the improvements above are based on suggestions/feedback from Daniel Vetter and Christian König. A shell script that can be run on a classic Linux environment to read out the DMA-BUF statistics can be found at [3](suggested by John Stultz). [1]: https://lore.kernel.org/patchwork/patch/1088791/ [2]: https://android-review.googlesource.com/q/topic:%22dmabuf-sysfs%22+(status:open%20OR%20status:merged) [3]: https://android-review.googlesource.com/c/platform/system/memory/libmeminfo/+/1549734 Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Hridya Valsaraju <hridya@google.com> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20210603214758.2955251-1-hridya@google.com
|
#
84335675 |
|
15-Jan-2021 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
dma-buf: Add debug option We have too many people abusing the struct page they can get at but really shouldn't in importers. Aside from that the backing page might simply not exist (for dynamic p2p mappings) looking at it and using it e.g. for mmap can also wreak the page handling of the exporter completely. Importers really must go through the proper interface like dma_buf_mmap for everything. I'm semi-tempted to enforce this for dynamic importers since those really have no excuse at all to break the rules. Unfortuantely we can't store the right pointers somewhere safe to make sure we oops on something recognizable, so best is to just wrangle them a bit by flipping all the bits. At least on x86 kernel addresses have all their high bits sets and the struct page array is fairly low in the kernel mapping, so flipping all the bits gives us a very high pointer in userspace and hence excellent chances for an invalid dereference. v2: Add a note to the @map_dma_buf hook that exporters shouldn't do fancy caching tricks, which would blow up with this address scrambling trick here (Chris) Enable by default when CONFIG_DMA_API_DEBUG is enabled. v3: Only one copy of the mangle/unmangle code (Christian) v4: #ifdef, not #if (0day) v5: sg_table can also be an ERR_PTR (Chris, Christian) Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: "Christian König" <christian.koenig@amd.com> Cc: David Stevens <stevensd@chromium.org> Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Link: https://patchwork.freedesktop.org/patch/msgid/20210115164739.3958206-1-daniel.vetter@ffwll.ch
|
#
c545781e |
|
11-Dec-2020 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
dma-buf: doc polish for pin/unpin Motivated by a discussion with Christian and Thomas: Try to untangle a bit what's relevant for importers and what's relevant for exporters. Also add an assert that really only dynamic importers use the api function, anything else doesn't make sense. Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: "Christian König" <christian.koenig@amd.com> Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Link: https://patchwork.freedesktop.org/patch/msgid/20201211155843.3348718-4-daniel.vetter@ffwll.ch
|
#
85804b70 |
|
11-Dec-2020 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
dma-buf: some kerneldoc formatting fixes Noticed while reviewing the output. Adds a bunch more links and fixes the function interface quoting. Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: "Christian König" <christian.koenig@amd.com> Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Link: https://patchwork.freedesktop.org/patch/msgid/20201211155843.3348718-2-daniel.vetter@ffwll.ch
|
#
de9114ec |
|
11-Dec-2020 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
dma-buf: Remove kmap kerneldoc vestiges Also try to clarify a bit when dma_buf_begin/end_cpu_access should be called. Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: "Christian König" <christian.koenig@amd.com> Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Link: https://patchwork.freedesktop.org/patch/msgid/20201211155843.3348718-1-daniel.vetter@ffwll.ch
|
#
476b485b |
|
10-Nov-2020 |
Jianxin Xiong <jianxin.xiong@intel.com> |
dma-buf: Document that dma-buf size is fixed The fact that the size of dma-buf is invariant over the lifetime of the buffer is mentioned in the comment of 'dma_buf_ops.mmap', but is not documented at where the info is defined. Add the missing documentation. Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/1605044477-51833-7-git-send-email-jianxin.xiong@intel.com
|
#
ac80cd17 |
|
14-Oct-2020 |
Jianxin Xiong <jianxin.xiong@intel.com> |
dma-buf: Clarify that dma-buf sg lists are page aligned The dma-buf API have been used under the assumption that the sg lists returned from dma_buf_map_attachment() are fully page aligned. Lots of stuff can break otherwise all over the place. Clarify this in the documentation and add a check when DMA API debug is enabled. Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/1602692161-107096-1-git-send-email-jianxin.xiong@intel.com
|
#
20e76f1a |
|
25-Sep-2020 |
Thomas Zimmermann <tzimmermann@suse.de> |
dma-buf: Use struct dma_buf_map in dma_buf_vunmap() interfaces This patch updates dma_buf_vunmap() and dma-buf's vunmap callback to use struct dma_buf_map. The interfaces used to receive a buffer address. This address is now given in an instance of the structure. Users of the functions are updated accordingly. This is only an interface change. It is currently expected that dma-buf memory can be accessed with system memory load/store operations. v2: * include dma-buf-heaps and i915 selftests (kernel test robot) * initialize cma_obj before using it in drm_gem_cma_free_object() (kernel test robot) Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Tomasz Figa <tfiga@chromium.org> Acked-by: Sam Ravnborg <sam@ravnborg.org> Link: https://patchwork.freedesktop.org/patch/msgid/20200925115601.23955-4-tzimmermann@suse.de
|
#
6619ccf1 |
|
25-Sep-2020 |
Thomas Zimmermann <tzimmermann@suse.de> |
dma-buf: Use struct dma_buf_map in dma_buf_vmap() interfaces This patch updates dma_buf_vmap() and dma-buf's vmap callback to use struct dma_buf_map. The interfaces used to return a buffer address. This address now gets stored in an instance of the structure that is given as an additional argument. The functions return an errno code on errors. Users of the functions are updated accordingly. This is only an interface change. It is currently expected that dma-buf memory can be accessed with system memory load/store operations. v3: * update fastrpc driver (kernel test robot) v2: * always clear map parameter in dma_buf_vmap() (Daniel) * include dma-buf-heaps and i915 selftests (kernel test robot) Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Tomasz Figa <tfiga@chromium.org> Acked-by: Sam Ravnborg <sam@ravnborg.org> Link: https://patchwork.freedesktop.org/patch/msgid/20200925115601.23955-3-tzimmermann@suse.de
|
#
01fd30da |
|
25-Sep-2020 |
Thomas Zimmermann <tzimmermann@suse.de> |
dma-buf: Add struct dma-buf-map for storing struct dma_buf.vaddr_ptr The new type struct dma_buf_map represents a mapping of dma-buf memory into kernel space. It contains a flag, is_iomem, that signals users to access the mapped memory with I/O operations instead of regular loads and stores. It was assumed that DMA buffer memory can be accessed with regular load and store operations. Some architectures, such as sparc64, require the use of I/O operations to access dma-map buffers that are located in I/O memory. Providing struct dma_buf_map allows drivers to implement this. This was specifically a problem when refreshing the graphics framebuffer on such systems. [1] As the first step, struct dma_buf stores an instance of struct dma_buf_map internally. Afterwards, dma-buf's vmap and vunmap interfaces are be converted. Finally, affected drivers can be fixed. v3: * moved documentation into separate patch * test for NULL pointers with !<ptr> [1] https://lore.kernel.org/dri-devel/20200725191012.GA434957@ravnborg.org/ Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Reviewed-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Sam Ravnborg <sam@ravnborg.org> Link: https://patchwork.freedesktop.org/patch/msgid/20200925115601.23955-2-tzimmermann@suse.de
|
#
0f50257f |
|
30-Aug-2020 |
Randy Dunlap <rdunlap@infradead.org> |
dma-buf: fix kernel-doc warning in <linux/dma-buf.h> Fix kernel-doc warning in <linux/dma-buf.h>: ../include/linux/dma-buf.h:330: warning: Function parameter or member 'name_lock' not described in 'dma_buf' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Gustavo Padovan <gustavo@padovan.org> Cc: Christian König <christian.koenig@amd.com> Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Reviewed-by: Christian König <christian.koenig@amd.com> Link: https://patchwork.freedesktop.org/patch/388523/ Signed-off-by: Christian König <christian.koenig@amd.com>
|
#
6348dd29 |
|
19-Jun-2020 |
Charan Teja Kalla <charante@codeaurora.org> |
dmabuf: use spinlock to access dmabuf->name There exists a sleep-while-atomic bug while accessing the dmabuf->name under mutex in the dmabuffs_dname(). This is caused from the SELinux permissions checks on a process where it tries to validate the inherited files from fork() by traversing them through iterate_fd() (which traverse files under spin_lock) and call match_file(security/selinux/hooks.c) where the permission checks happen. This audit information is logged using dump_common_audit_data() where it calls d_path() to get the file path name. If the file check happen on the dmabuf's fd, then it ends up in ->dmabuffs_dname() and use mutex to access dmabuf->name. The flow will be like below: flush_unauthorized_files() iterate_fd() spin_lock() --> Start of the atomic section. match_file() file_has_perm() avc_has_perm() avc_audit() slow_avc_audit() common_lsm_audit() dump_common_audit_data() audit_log_d_path() d_path() dmabuffs_dname() mutex_lock()--> Sleep while atomic. Call trace captured (on 4.19 kernels) is below: ___might_sleep+0x204/0x208 __might_sleep+0x50/0x88 __mutex_lock_common+0x5c/0x1068 __mutex_lock_common+0x5c/0x1068 mutex_lock_nested+0x40/0x50 dmabuffs_dname+0xa0/0x170 d_path+0x84/0x290 audit_log_d_path+0x74/0x130 common_lsm_audit+0x334/0x6e8 slow_avc_audit+0xb8/0xf8 avc_has_perm+0x154/0x218 file_has_perm+0x70/0x180 match_file+0x60/0x78 iterate_fd+0x128/0x168 selinux_bprm_committing_creds+0x178/0x248 security_bprm_committing_creds+0x30/0x48 install_exec_creds+0x1c/0x68 load_elf_binary+0x3a4/0x14e0 search_binary_handler+0xb0/0x1e0 So, use spinlock to access dmabuf->name to avoid sleep-while-atomic. Cc: <stable@vger.kernel.org> [5.3+] Signed-off-by: Charan Teja Kalla <charante@codeaurora.org> Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com> Acked-by: Christian König <christian.koenig@amd.com> [sumits: added comment to spinlock_t definition to avoid warning] Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/a83e7f0d-4e54-9848-4b58-e1acdbe06735@codeaurora.org
|
#
6f49c251 |
|
07-Apr-2020 |
Randy Dunlap <rdunlap@infradead.org> |
dma-buf: fix documentation build warnings Fix documentation warnings in dma-buf.[hc]: ../drivers/dma-buf/dma-buf.c:678: warning: Function parameter or member 'importer_ops' not described in 'dma_buf_dynamic_attach' ../drivers/dma-buf/dma-buf.c:678: warning: Function parameter or member 'importer_priv' not described in 'dma_buf_dynamic_attach' ../include/linux/dma-buf.h:339: warning: Incorrect use of kernel-doc format: * @move_notify Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/7bcbe6fe-0b4b-87da-d003-b68a26eb4cf0@infradead.org
|
#
09606b54 |
|
22-Mar-2018 |
Christian König <christian.koenig@amd.com> |
dma-buf: add peer2peer flag Add a peer2peer flag noting that the importer can deal with device resources which are not backed by pages. Signed-off-by: Christian König <christian.koenig@amd.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Link: https://patchwork.freedesktop.org/patch/359286/
|
#
bd2275ee |
|
18-Feb-2020 |
Christian König <christian.koenig@amd.com> |
dma-buf: drop dynamic_mapping flag Instead use the pin() callback to detect dynamic DMA-buf handling. Since amdgpu is now migrated it doesn't make much sense to keep the extra flag. Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/353997/?series=73646&rev=1
|
#
bb42df46 |
|
03-Jul-2018 |
Christian König <christian.koenig@amd.com> |
dma-buf: add dynamic DMA-buf handling v15 On the exporter side we add optional explicit pinning callbacks. Which are called when the importer doesn't implement dynamic handling, move notification or need the DMA-buf locked in place for its use case. On the importer side we add an optional move_notify callback. This callback is used by the exporter to inform the importers that their mappings should be destroyed as soon as possible. This allows the exporter to provide the mappings without the need to pin the backing store. v2: don't try to invalidate mappings when the callback is NULL, lock the reservation obj while using the attachments, add helper to set the callback v3: move flag for invalidation support into the DMA-buf, use new attach_info structure to set the callback v4: use importer_priv field instead of mangling exporter priv. v5: drop invalidation_supported flag v6: squash together with pin/unpin changes v7: pin/unpin takes an attachment now v8: nuke dma_buf_attachment_(map|unmap)_locked, everything is now handled backward compatible v9: always cache when export/importer don't agree on dynamic handling v10: minimal style cleanup v11: drop automatically re-entry avoidance v12: rename callback to move_notify v13: add might_lock in appropriate places v14: rebase on separated locking change v15: add EXPERIMENTAL flag, some more code comments Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/353993/?series=73646&rev=1
|
#
4337ebbb |
|
18-Nov-2019 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
dma-buf: Remove kernel map/unmap hooks All implementations are gone now. Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Link: https://patchwork.freedesktop.org/patch/msgid/20191118103536.17675-16-daniel.vetter@ffwll.ch
|
#
7f0de8d8 |
|
18-Nov-2019 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
dma-buf: Drop dma_buf_k(un)map It's unused. 10 years ago, back when 32bit was still fairly common and trying to not exhaust vmalloc space sounded like a worthwhile goal, adding these to dma_buf made sense. Reality is that they simply never caught on, and nowadays everyone who needs plenty of buffers will run in 64bit mode anyway. Also update the docs in this area to adjust them to reality. The actual hooks in dma_buf_ops will be removed once all the implementations are gone. Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Link: https://patchwork.freedesktop.org/patch/msgid/20191118103536.17675-10-daniel.vetter@ffwll.ch
|
#
15fd552d |
|
03-Jul-2018 |
Christian König <christian.koenig@amd.com> |
dma-buf: change DMA-buf locking convention v3 This patch is a stripped down version of the locking changes necessary to support dynamic DMA-buf handling. It adds a dynamic flag for both importers as well as exporters so that drivers can choose if they want the reservation object locked or unlocked during mapping of attachments. For compatibility between drivers we cache the DMA-buf mapping during attaching an importer as soon as exporter/importer disagree on the dynamic handling. Issues and solutions we considered: - We can't change all existing drivers, and existing improters have strong opinions about which locks they're holding while calling dma_buf_attachment_map/unmap. Exporters also have strong opinions about which locks they can acquire in their ->map/unmap callbacks, levaing no room for change. The solution to avoid this was to move the actual map/unmap out from this call, into the attach/detach callbacks, and cache the mapping. This works because drivers don't call attach/detach from deep within their code callchains (like deep in memory management code called from cs/execbuf ioctl), but directly from the fd2handle implementation. - The caching has some troubles on some soc drivers, which set other modes than DMA_BIDIRECTIONAL. We can't have 2 incompatible mappings, and we can't re-create the mapping at _map time due to the above locking fun. We very carefuly step around that by only caching at attach time if the dynamic mode between importer/expoert mismatches. - There's been quite some discussion on dma-buf mappings which need active cache management, which would all break down when caching, plus we don't have explicit flush operations on the attachment side. The solution to this was to shrug and keep the current discrepancy between what the dma-buf docs claim and what implementations do, with the hope that the begin/end_cpu_access hooks are good enough and that all necessary flushing to keep device mappings consistent will be done there. v2: cleanup set_name merge, improve kerneldoc v3: update commit message, kerneldoc and cleanup _debug_show() Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/336788/
|
#
52791eee |
|
11-Aug-2019 |
Christian König <christian.koenig@amd.com> |
dma-buf: rename reservation_object to dma_resv Be more consistent with the naming of the other DMA-buf objects. Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Link: https://patchwork.freedesktop.org/patch/323401/
|
#
caab277b |
|
02-Jun-2019 |
Thomas Gleixner <tglx@linutronix.de> |
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 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 version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 503 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Enrico Weigelt <info@metux.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
#
bb2bb903 |
|
13-Jun-2019 |
Greg Hackmann <ghackmann@google.com> |
dma-buf: add DMA_BUF_SET_NAME ioctls This patch adds complimentary DMA_BUF_SET_NAME ioctls, which lets userspace processes attach a free-form name to each buffer. This information can be extremely helpful for tracking and accounting shared buffers. For example, on Android, we know what each buffer will be used for at allocation time: GL, multimedia, camera, etc. The userspace allocator can use DMA_BUF_SET_NAME to associate that information with the buffer, so we can later give developers a breakdown of how much memory they're allocating for graphics, camera, etc. Signed-off-by: Greg Hackmann <ghackmann@google.com> Signed-off-by: Chenbo Feng <fengc@google.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20190613223408.139221-3-fengc@google.com
|
#
f13e143e |
|
03-Jul-2018 |
Christian König <christian.koenig@amd.com> |
dma-buf: start caching of sg_table objects v2 To allow a smooth transition from pinning buffer objects to dynamic invalidation we first start to cache the sg_table for an attachment. v2: keep closer to the DRM implementation Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.kernel.org/patch/10943053/
|
#
d5ae7712 |
|
21-Mar-2019 |
Andrew F. Davis <afd@ti.com> |
dma-buf: Update [un]map documentation to match the other functions Other function have inline documentation, a couple still have theirs at the top of the structure, update the docs and move them inline. Signed-off-by: Andrew F. Davis <afd@ti.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20190321200957.16938-2-afd@ti.com
|
#
67b886d2 |
|
21-Mar-2019 |
Andrew F. Davis <afd@ti.com> |
dma-buf: Remove leftover [un]map_atomic comments The map_atomic/unmap_atomic callbacks have been removed, remove the related comments. Fixes: f664a5269542 ("dma-buf: remove kmap_atomic interface") Signed-off-by: Andrew F. Davis <afd@ti.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20190321200957.16938-1-afd@ti.com
|
#
f664a5269 |
|
28-May-2018 |
Christian König <christian.koenig@amd.com> |
dma-buf: remove kmap_atomic interface Neither used nor correctly implemented anywhere. Just completely remove the interface. Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Link: https://patchwork.freedesktop.org/patch/226645/
|
#
a19741e5 |
|
28-May-2018 |
Christian König <christian.koenig@amd.com> |
dma_buf: remove device parameter from attach callback v2 The device parameter is completely unused because it is available in the attachment structure as well. v2: fix kerneldoc as well Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/226643/
|
#
09ea0dfb |
|
29-May-2018 |
Gerd Hoffmann <kraxel@redhat.com> |
dma-buf: make map_atomic and map function pointers optional So drivers don't need dummy functions just returning NULL. Cc: Daniel Vetter <daniel@ffwll.ch> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Link: http://patchwork.freedesktop.org/patch/msgid/20180529135918.19729-1-kraxel@redhat.com
|
#
01e5d556 |
|
03-Jul-2017 |
Al Viro <viro@zeniv.linux.org.uk> |
dmabuf: annotate dma_buf->active Contains POLL... bitmaps Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
#
f9b67f00 |
|
19-Apr-2017 |
Logan Gunthorpe <logang@deltatee.com> |
dma-buf: Rename dma-ops to prevent conflict with kunmap_atomic macro Seeing the kunmap_atomic dma_buf_ops share the same name with a macro in highmem.h, the former can be aliased if any dma-buf user includes that header. I'm personally trying to include highmem.h inside scatterlist.h and this breaks the dma-buf code proper. Christoph Hellwig suggested [1] renaming it and pushing this patch ASAP. To maintain consistency I've renamed all four of kmap* and kunmap* to be map* and unmap*. (Even though only kmap_atomic presently conflicts.) [1] https://www.spinics.net/lists/target-devel/msg15070.html Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Sinclair Yeh <syeh@vmware.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Link: http://patchwork.freedesktop.org/patch/msgid/1492630570-879-1-git-send-email-logang@deltatee.com
|
#
e9b4d7b5 |
|
29-Dec-2016 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
dma-buf: Use recommended structure member reference I just learned that &struct_name.member_name works and looks pretty even. It doesn't (yet) link to the member directly though, which would be really good for big structures or vfunc tables (where the per-member kerneldoc tends to be long). Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1483044517-5770-5-git-send-email-daniel.vetter@ffwll.ch
|
#
f641d3b5 |
|
29-Dec-2016 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
dma-buf: use preferred struct reference in kernel-doc sed -e 's/\( \* .*\)struct &\([_a-z]*\)/\1\&struct \2/' -i Originally I wasnt a friend of this style because I thought a line-break between the "&struct" and "foo" part would break it. But a quick test shows that " * &struct \n * foo\n" works pefectly well with current kernel-doc. So time to mass-apply these changes! Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1483044517-5770-4-git-send-email-daniel.vetter@ffwll.ch
|
#
0959a168 |
|
09-Dec-2016 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
dma-buf: Update cpu access documentation - Again move the information relevant for driver writers next to the callbacks. - Put the overview and userspace interface documentation into a DOC: section within the code. - Remove the text that mmap needs to be coherent - since the DMA_BUF_IOCTL_SYNC landed that's no longer the case. But keep the text that for pte zapping exporters need to adjust the address space. - Add a FIXME that kmap and the new begin/end stuff used by the SYNC ioctl don't really mix correctly. That's something I just realized while doing this doc rework. - Augment function and structure docs like usual. Cc: linux-doc@vger.kernel.org Cc: Jonathan Corbet <corbet@lwn.net> Cc: Sumit Semwal <sumit.semwal@linaro.org> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> [sumits: fix cosmetic issues] Link: http://patchwork.freedesktop.org/patch/msgid/20161209185309.1682-5-daniel.vetter@ffwll.ch
|
#
2904a8c1 |
|
09-Dec-2016 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
dma-buf: Reorganize device dma access docs - Put the initial overview for dma-buf into dma-buf.rst. - Put all the comments about detailed semantics into the right kernel-doc comment for functions or ops structure member. - To allow that detail, switch the reworked kerneldoc to inline style for dma_buf_ops. - Tie everything together into a much more streamlined overview comment, relying on the hyperlinks for all the details. - Also sprinkle some links into the kerneldoc for dma_buf and dma_buf_attachment to tie it all together. Cc: linux-doc@vger.kernel.org Cc: Jonathan Corbet <corbet@lwn.net> Cc: Sumit Semwal <sumit.semwal@linaro.org> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Link: http://patchwork.freedesktop.org/patch/msgid/20161209185309.1682-4-daniel.vetter@ffwll.ch
|
#
f54d1867 |
|
25-Oct-2016 |
Chris Wilson <chris@chris-wilson.co.uk> |
dma-buf: Rename struct fence to dma_fence I plan to usurp the short name of struct fence for a core kernel struct, and so I need to rename the specialised fence/timeline for DMA operations to make room. A consensus was reached in https://lists.freedesktop.org/archives/dri-devel/2016-July/113083.html that making clear this fence applies to DMA operations was a good thing. Since then the patch has grown a bit as usage increases, so hopefully it remains a good thing! (v2...: rebase, rerun spatch) v3: Compile on msm, spotted a manual fixup that I broke. v4: Try again for msm, sorry Daniel coccinelle script: @@ @@ - struct fence + struct dma_fence @@ @@ - struct fence_ops + struct dma_fence_ops @@ @@ - struct fence_cb + struct dma_fence_cb @@ @@ - struct fence_array + struct dma_fence_array @@ @@ - enum fence_flag_bits + enum dma_fence_flag_bits @@ @@ ( - fence_init + dma_fence_init | - fence_release + dma_fence_release | - fence_free + dma_fence_free | - fence_get + dma_fence_get | - fence_get_rcu + dma_fence_get_rcu | - fence_put + dma_fence_put | - fence_signal + dma_fence_signal | - fence_signal_locked + dma_fence_signal_locked | - fence_default_wait + dma_fence_default_wait | - fence_add_callback + dma_fence_add_callback | - fence_remove_callback + dma_fence_remove_callback | - fence_enable_sw_signaling + dma_fence_enable_sw_signaling | - fence_is_signaled_locked + dma_fence_is_signaled_locked | - fence_is_signaled + dma_fence_is_signaled | - fence_is_later + dma_fence_is_later | - fence_later + dma_fence_later | - fence_wait_timeout + dma_fence_wait_timeout | - fence_wait_any_timeout + dma_fence_wait_any_timeout | - fence_wait + dma_fence_wait | - fence_context_alloc + dma_fence_context_alloc | - fence_array_create + dma_fence_array_create | - to_fence_array + to_dma_fence_array | - fence_is_array + dma_fence_is_array | - trace_fence_emit + trace_dma_fence_emit | - FENCE_TRACE + DMA_FENCE_TRACE | - FENCE_WARN + DMA_FENCE_WARN | - FENCE_ERR + DMA_FENCE_ERR ) ( ... ) Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/20161025120045.28839-1-chris@chris-wilson.co.uk
|
#
bd3e2208 |
|
19-Jun-2016 |
Mathias Krause <minipli@googlemail.com> |
dma-buf: remove dma_buf_debugfs_create_file() There is only a single user of dma_buf_debugfs_create_file() and that one got the function pointer cast wrong. With that one fixed, there is no need to have a wrapper for debugfs_create_file(), just call it directly. With no users left, we can remove dma_buf_debugfs_create_file(). While at it, simplify the error handling in dma_buf_init_debugfs() slightly. Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Link: http://patchwork.freedesktop.org/patch/msgid/1466339491-12639-2-git-send-email-minipli@googlemail.com
|
#
e2082e3a |
|
31-Mar-2016 |
Rob Clark <robdclark@gmail.com> |
dma-buf: headerdoc fixes Apparently nobody noticed that dma-buf.h wasn't actually pulled into docbook build. And as a result the headerdoc comments bitrot a bit. Add missing params/fields. Signed-off-by: Rob Clark <robdclark@gmail.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
|
#
18b862dc |
|
18-Mar-2016 |
Chris Wilson <chris@chris-wilson.co.uk> |
dma-buf, drm, ion: Propagate error code from dma_buf_start_cpu_access() Drivers, especially i915.ko, can fail during the initial migration of a dma-buf for CPU access. However, the error code from the driver was not being propagated back to ioctl and so userspace was blissfully ignorant of the failure. Rendering corruption ensues. Whilst fixing the ioctl to return the error code from dma_buf_start_cpu_access(), also do the same for dma_buf_end_cpu_access(). For most drivers, dma_buf_end_cpu_access() cannot fail. i915.ko however, as most drivers would, wants to avoid being uninterruptible (as would be required to guarrantee no failure when flushing the buffer to the device). As userspace already has to handle errors from the SYNC_IOCTL, take advantage of this to be able to restart the syscall across signals. This fixes a coherency issue for i915.ko as well as reducing the uninterruptible hold upon its BKL, the struct_mutex. Fixes commit c11e391da2a8fe973c3c2398452000bed505851e Author: Daniel Vetter <daniel.vetter@ffwll.ch> Date: Thu Feb 11 20:04:51 2016 -0200 dma-buf: Add ioctls to allow userspace to flush Testcase: igt/gem_concurrent_blit/*dmabuf*interruptible Testcase: igt/prime_mmap_coherency/ioctl-errors Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tiago Vignatti <tiago.vignatti@intel.com> Cc: Stéphane Marchesin <marcheu@chromium.org> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Daniel Vetter <daniel.vetter@intel.com> CC: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Cc: intel-gfx@lists.freedesktop.org Cc: devel@driverdev.osuosl.org Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1458331359-2634-1-git-send-email-chris@chris-wilson.co.uk
|
#
831e9da7 |
|
22-Dec-2015 |
Tiago Vignatti <tiago.vignatti@intel.com> |
dma-buf: Remove range-based flush This patch removes range-based information used for optimizations in begin_cpu_access and end_cpu_access. We don't have any user nor implementation using range-based flush. It seems a consensus that if we ever want something like that again (or even more robust using 2D, 3D sub-range regions) we can use the upcoming dma-buf sync ioctl for such. Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Daniel Vetter <daniel.vetter@intel.com> Signed-off-by: Tiago Vignatti <tiago.vignatti@intel.com> Reviewed-by: Stéphane Marchesin <marcheu@chromium.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1450820214-12509-3-git-send-email-tiago.vignatti@intel.com
|
#
9abdffe2 |
|
05-May-2015 |
Sumit Semwal <sumit.semwal@linaro.org> |
dma-buf: add ref counting for module as exporter Add reference counting on a kernel module that exports dma-buf and implements its operations. This prevents the module from being unloaded while DMABUF file is in use. The original patch [1] was submitted by Tomasz Stanislawski, but this is a simpler way to do it. v3: call module_put() as late as possible, per gregkh's comment. v2: move owner to struct dma_buf, and use DEFINE_DMA_BUF_EXPORT_INFO macro to simplify the change. Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> [1]: https://lkml.org/lkml/2012/8/8/163
|
#
d8fbe341 |
|
22-Jan-2015 |
Sumit Semwal <sumit.semwal@linaro.org> |
dma-buf: cleanup dma_buf_export() to make it easily extensible At present, dma_buf_export() takes a series of parameters, which makes it difficult to add any new parameters for exporters, if required. Make it simpler by moving all these parameters into a struct, and pass the struct * as parameter to dma_buf_export(). While at it, unite dma_buf_export_named() with dma_buf_export(), and change all callers accordingly. Reviewed-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Acked-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
|
#
9b495a58 |
|
30-Jun-2014 |
Maarten Lankhorst <maarten.lankhorst@canonical.com> |
dma-buf: add poll support, v3 Thanks to Fengguang Wu for spotting a missing static cast. v2: - Kill unused variable need_shared. v3: - Clarify the BUG() in dma_buf_release some more. (Rob Clark) Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Daniel Vetter <daniel@ffwll.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
#
3aac4502 |
|
30-Jun-2014 |
Maarten Lankhorst <maarten.lankhorst@canonical.com> |
dma-buf: use reservation objects This allows reservation objects to be used in dma-buf. it's required for implementing polling support on the fences that belong to a dma-buf. Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> Acked-by: Mauro Carvalho Chehab <m.chehab@samsung.com> #drivers/media/v4l2-core/ Acked-by: Thomas Hellstrom <thellstrom@vmware.com> #drivers/gpu/drm/ttm Acked-by: Sumit Semwal <sumit.semwal@linaro.org> Acked-by: Daniel Vetter <daniel@ffwll.ch> Signed-off-by: Vincent Stehlé <vincent.stehle@laposte.net> #drivers/gpu/drm/armada/ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
#
c0b00a52 |
|
03-Feb-2014 |
Sumit Semwal <sumit.semwal@linaro.org> |
dma-buf: update debugfs output Russell King observed 'wierd' looking output from debugfs, and also suggested better ways of getting device names (use KBUILD_MODNAME, dev_name()) This patch addresses these issues to make the debugfs output correct and better looking. While at it, replace seq_printf with seq_puts to remove the checkpatch.pl warnings. Reported-by: Russell King - ARM Linux <linux@arm.linux.org.uk> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
|
#
b89e3563 |
|
04-Apr-2013 |
Sumit Semwal <sumit.semwal@linaro.org> |
dma-buf: Add debugfs support Add debugfs support to make it easier to print debug information about the dma-buf buffers. Cc: Dave Airlie <airlied@redhat.com> [minor fixes on init and warning fix] Cc: Dan Carpenter <dan.carpenter@oracle.com> [remove double unlock in fail case] Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
|
#
78df9695 |
|
22-Mar-2013 |
Sumit Semwal <sumit.semwal@linaro.org> |
dma-buf: replace dma_buf_export() with dma_buf_export_named() For debugging purposes, it is useful to have a name-string added while exporting buffers. Hence, dma_buf_export() is replaced with dma_buf_export_named(), which additionally takes 'exp_name' as a parameter. For backward compatibility, and for lazy exporters who don't wish to name themselves, a #define dma_buf_export() is also made available, which adds a __FILE__ instead of 'exp_name'. Cc: Daniel Vetter <daniel.vetter@ffwll.ch> [Thanks for the idea!] Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
|
#
f00b4dad |
|
20-Dec-2012 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
dma-buf: implement vmap refcounting in the interface logic All drivers which implement this need to have some sort of refcount to allow concurrent vmap usage. Hence implement this in the dma-buf core. To protect against concurrent calls we need a lock, which potentially causes new funny locking inversions. But this shouldn't be a problem for exporters with statically allocated backing storage, and more dynamic drivers have decent issues already anyway. Inspired by some refactoring patches from Aaron Plattner, who implemented the same idea, but only for drm/prime drivers. v2: Check in dma_buf_release that no dangling vmaps are left. Suggested by Aaron Plattner. We might want to do similar checks for attachments, but that's for another patch. Also fix up ERR_PTR return for vmap. v3: Check whether the passed-in vmap address matches with the cached one for vunmap. Eventually we might want to remove that parameter - compared to the kmap functions there's no need for the vaddr for unmapping. Suggested by Chris Wilson. v4: Fix a brown-paper-bag bug spotted by Aaron Plattner. Cc: Aaron Plattner <aplattner@nvidia.com> Reviewed-by: Aaron Plattner <aplattner@nvidia.com> Tested-by: Aaron Plattner <aplattner@nvidia.com> Reviewed-by: Rob Clark <rob@ti.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
|
#
8a168ca7 |
|
28-Dec-2012 |
Masanari Iida <standby24x7@gmail.com> |
treewide: Fix typo in various drivers Correct spelling typo in printk within various drivers. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
|
#
ada65c74 |
|
12-Dec-2012 |
Maarten Lankhorst <maarten.lankhorst@canonical.com> |
dma-buf: remove fallback for !CONFIG_DMA_SHARED_BUFFER Documentation says that code requiring dma-buf should add it to select, so inline fallbacks are not going to be used. A link error will make it obvious what went wrong, instead of silently doing nothing at runtime. Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Rob Clark <rob.clark@linaro.org> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
|
#
12c4727e |
|
23-May-2012 |
Sumit Semwal <sumit.semwal@ti.com> |
dma-buf: minor documentation fixes. Some minor inline documentation fixes for gaps resulting from new patches. Signed-off-by: Sumit Semwal <sumit.semwal@ti.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
|
#
98f86c9e |
|
19-May-2012 |
Dave Airlie <airlied@redhat.com> |
dma-buf: add vmap interface The main requirement I have for this interface is for scanning out using the USB gpu devices. Since these devices have to read the framebuffer on updates and linearly compress it, using kmaps is a major overhead for every update. v2: fix warn issues pointed out by Sylwester Nawrocki. v3: fix compile !CONFIG_DMA_SHARED_BUFFER and add _GPL for now Signed-off-by: Dave Airlie <airlied@redhat.com> Reviewed-by: Rob Clark <rob.clark@linaro.org> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
|
#
4c78513e |
|
24-Apr-2012 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
dma-buf: mmap support Compared to Rob Clark's RFC I've ditched the prepare/finish hooks and corresponding ioctls on the dma_buf file. The major reason for that is that many people seem to be under the impression that this is also for synchronization with outstanding asynchronous processsing. I'm pretty massively opposed to this because: - It boils down reinventing a new rather general-purpose userspace synchronization interface. If we look at things like futexes, this is hard to get right. - Furthermore a lot of kernel code has to interact with this synchronization primitive. This smells a look like the dri1 hw_lock, a horror show I prefer not to reinvent. - Even more fun is that multiple different subsystems would interact here, so we have plenty of opportunities to create funny deadlock scenarios. I think synchronization is a wholesale different problem from data sharing and should be tackled as an orthogonal problem. Now we could demand that prepare/finish may only ensure cache coherency (as Rob intended), but that runs up into the next problem: We not only need mmap support to facilitate sw-only processing nodes in a pipeline (without jumping through hoops by importing the dma_buf into some sw-access only importer), which allows for a nicer ION->dma-buf upgrade path for existing Android userspace. We also need mmap support for existing importing subsystems to support existing userspace libraries. And a loot of these subsystems are expected to export coherent userspace mappings. So prepare/finish can only ever be optional and the exporter /needs/ to support coherent mappings. Given that mmap access is always somewhat fallback-y in nature I've decided to drop this optimization, instead of just making it optional. If we demonstrate a clear need for this, supported by benchmark results, we can always add it in again later as an optional extension. Other differences compared to Rob's RFC is the above mentioned support for mapping a dma-buf through facilities provided by the importer. Which results in mmap support no longer being optional. Note that this dma-buf mmap patch does _not_ support every possible insanity an existing subsystem could pull of with mmap: Because it does not allow to intercept pagefaults and shoot down ptes importing subsystems can't add some magic of their own at these points (e.g. to automatically synchronize with outstanding rendering or set up some special resources). I've done a cursory read through a few mmap implementions of various subsytems and I'm hopeful that we can avoid this (and the complexity it'd bring with it). Additonally I've extended the documentation a bit to explain the hows and whys of this mmap extension. In case we ever want to add support for explicitly cache maneged userspace mmap with a prepare/finish ioctl pair, we could specify that userspace needs to mmap a different part of the dma_buf, e.g. the range starting at dma_buf->size up to dma_buf->size*2. This works because the size of a dma_buf is invariant over it's lifetime. The exporter would obviously need to fall back to coherent mappings for both ranges if a legacy clients maps the coherent range and the architecture cannot suppor conflicting caching policies. Also, this would obviously be optional and userspace needs to be able to fall back to coherent mappings. v2: - Spelling fixes from Rob Clark. - Compile fix for !DMA_BUF from Rob Clark. - Extend commit message to explain how explicitly cache managed mmap support could be added later. - Extend the documentation with implementations notes for exporters that need to manually fake coherency. v3: - dma_buf pointer initialization goof-up noticed by Rebecca Schultz Zavin. Cc: Rob Clark <rob.clark@linaro.org> Cc: Rebecca Schultz Zavin <rebecca@android.com> Acked-by: Rob Clark <rob.clark@linaro.org> Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
|
#
3e0b2a19 |
|
25-Mar-2012 |
Sumit Semwal <sumit.semwal@ti.com> |
dma-buf: correct dummy function declarations. Dummy functions for the newly added cpu access ops need variable names for arguments. Also, the introduction of flags in dma_buf_fd needs to be added to dummy functions as well. Signed-off-by: Sumit Semwal <sumit.semwal@ti.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
|
#
fc13020e |
|
19-Mar-2012 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
dma-buf: add support for kernel cpu access Big differences to other contenders in the field (like ion) is that this also supports highmem, so we have to split up the cpu access from the kernel side into a prepare and a kmap step. Prepare is allowed to fail and should do everything required so that the kmap calls can succeed (like swapin/backing storage allocation, flushing, ...). More in-depth explanations will follow in the follow-up documentation patch. Changes in v2: - Clear up begin_cpu_access confusion noticed by Sumit Semwal. - Don't automatically fallback from the _atomic variants to the non-atomic variants. The _atomic callbacks are not allowed to sleep, so we want exporters to make this decision explicit. The function signatures are explicit, so simpler exporters can still use the same function for both. - Make the unmap functions optional. Simpler exporters with permanent mappings don't need to do anything at unmap time. Changes in v3: - Adjust the WARN_ON checks for the new ->ops functions as suggested by Rob Clark and Sumit Semwal. - Rebased on top of latest dma-buf-next git. Changes in v4: - Fixup a missing - in a return -EINVAL; statement. Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Rob Clark <rob@ti.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
|
#
6b607e3a |
|
18-Mar-2012 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
dma-buf: don't hold the mutex around map/unmap calls The mutex protects the attachment list and hence needs to be held around the callbakc to the exporters (optional) attach/detach functions. Holding the mutex around the map/unmap calls doesn't protect any dma_buf state. Exporters need to properly protect any of their own state anyway (to protect against calls from their own interfaces). So this only makes the locking messier (and lockdep easier to anger). Therefore let's just drop this. v2: Rebased on top of latest dma-buf-next git. Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Rob Clark <rob.clark@linaro.org> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
|
#
f9a24d1a |
|
16-Mar-2012 |
Rob Clark <rob@ti.com> |
dma-buf: add get_dma_buf() Works in a similar way to get_file(), and is needed in cases such as when the exporter needs to also keep a reference to the dmabuf (that is later released with a dma_buf_put()), and possibly other similar cases. Signed-off-by: Rob Clark <rob@ti.com> Reviewed-by: Dave Airlie <airlied@redhat.com> Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
|
#
55c1c4ca |
|
16-Mar-2012 |
Dave Airlie <airlied@redhat.com> |
dma-buf: pass flags into dma_buf_fd. We need to pass the flags into dma_buf_fd at this point, so the flags end up doing the right thing for O_CLOEXEC. Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Rob Clark <rob@ti.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
|
#
33ea2dcb |
|
27-Jan-2012 |
Sumit Semwal <sumit.semwal@ti.com> |
dma-buf: add dma_data_direction to unmap dma_buf_op Some exporters may use DMA map/unmap APIs in dma-buf ops, which require enum dma_data_direction for both map and unmap operations. Thus, the unmap dma_buf_op also needs to have enum dma_data_direction as a parameter. Reported-by: Tomasz Stanislawski <t.stanislaws@samsung.com> Signed-off-by: Sumit Semwal <sumit.semwal@ti.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
|
#
5375764f |
|
25-Jan-2012 |
Laurent Pinchart <laurent.pinchart@ideasonboard.com> |
dma-buf: Constify ops argument to dma_buf_export() This allows drivers to make the dma buf operations structure constant. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
|
#
313162d0 |
|
30-Jan-2012 |
Paul Gortmaker <paul.gortmaker@windriver.com> |
device.h: audit and cleanup users in main include dir The <linux/device.h> header includes a lot of stuff, and it in turn gets a lot of use just for the basic "struct device" which appears so often. Clean up the users as follows: 1) For those headers only needing "struct device" as a pointer in fcn args, replace the include with exactly that. 2) For headers not really using anything from device.h, simply delete the include altogether. 3) For headers relying on getting device.h implicitly before being included themselves, now explicitly include device.h 4) For files in which doing #1 or #2 uncovers an implicit dependency on some other header, fix by explicitly adding the required header(s). Any C files that were implicitly relying on device.h to be present have already been dealt with in advance. Total removals from #1 and #2: 51. Total additions coming from #3: 9. Total other implicit dependencies from #4: 7. As of 3.3-rc1, there were 110, so a net removal of 42 gives about a 38% reduction in device.h presence in include/* Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
|
#
d15bd7ee |
|
26-Dec-2011 |
Sumit Semwal <sumit.semwal@ti.com> |
dma-buf: Introduce dma buffer sharing mechanism This is the first step in defining a dma buffer sharing mechanism. A new buffer object dma_buf is added, with operations and API to allow easy sharing of this buffer object across devices. The framework allows: - creation of a buffer object, its association with a file pointer, and associated allocator-defined operations on that buffer. This operation is called the 'export' operation. - different devices to 'attach' themselves to this exported buffer object, to facilitate backing storage negotiation, using dma_buf_attach() API. - the exported buffer object to be shared with the other entity by asking for its 'file-descriptor (fd)', and sharing the fd across. - a received fd to get the buffer object back, where it can be accessed using the associated exporter-defined operations. - the exporter and user to share the scatterlist associated with this buffer object using map_dma_buf and unmap_dma_buf operations. Atleast one 'attach()' call is required to be made prior to calling the map_dma_buf() operation. Couple of building blocks in map_dma_buf() are added to ease introduction of sync'ing across exporter and users, and late allocation by the exporter. For this first version, this framework will work with certain conditions: - *ONLY* exporter will be allowed to mmap to userspace (outside of this framework - mmap is not a buffer object operation), - currently, *ONLY* users that do not need CPU access to the buffer are allowed. More details are there in the documentation patch. This is based on design suggestions from many people at the mini-summits[1], most notably from Arnd Bergmann <arnd@arndb.de>, Rob Clark <rob@ti.com> and Daniel Vetter <daniel@ffwll.ch>. The implementation is inspired from proof-of-concept patch-set from Tomasz Stanislawski <t.stanislaws@samsung.com>, who demonstrated buffer sharing between two v4l2 devices. [2] [1]: https://wiki.linaro.org/OfficeofCTO/MemoryManagement [2]: http://lwn.net/Articles/454389 Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Signed-off-by: Sumit Semwal <sumit.semwal@ti.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Dave Airlie <airlied@redhat.com> Reviewed-and-Tested-by: Rob Clark <rob.clark@linaro.org> Signed-off-by: Dave Airlie <airlied@redhat.com>
|