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android / kernel / common / 34364883b1f7cf8aed0e3a36e38aa7803c73b203
commit34364883b1f7cf8aed0e3a36e38aa7803c73b203[log] [tgz]
authorChao Hao <chao.hao@mediatek.com>Wed Aug 12 17:28:44 2020 +0800
committerHridya Valsaraju <hridya@google.com>Thu Aug 27 21:06:54 2020 +0000
treea8d00e1bdf19437f0c2b41363ca15f4f1a9968c6
parentf058ed1ec2aaa13c313f42b46035a074f71920eb [diff]
ANDROID: ion: export some ion symbols

Background:
  We can allocate buffer from ion_system_heap for general case,
if the buffer is needed to access by HW, we need to map/unmap
dma_address by iommu driver before and after HW engine access for
iommu case. For example, if the same buffer is accessed by three
HW engines, then every device driver needs to map/unmap dma_address
by iommu driver respectively.
  For MTK platform, all the multimedia HW engines use the same
iommu HW and share the same iommu page table, so multiple map/unmap
dma_address by iommu driver maybe reduce performance seriously for
above case, especially for big size buffer. In order to improve
performance for MTK platform, we want to add ion_mtk_iommu_heap
and implement map/unmap dma_address by ion_mtk_iommu_heap:
  a.heap->buf_ops.map_dma_buf: If more than one attachments map
dma_address by iommu driver about the same buffer, the function
only map once in first attachment, the other attachments of buffer
copy sg_table which has already mapped to respective sg_table directly
and don't mapping dma_address truly.
  b.heap->buf_ops.unmap_dma_buf: Do nothing.
  c.heap->buf_ops.release: unmap dma_address by iommu driver about buffer
and free the buffer.

Based on above description:
We will build ion_mtk_iommu_heap as a kernel module and ion_mtk_iommu_heap
also use some APIs like ion_system_heap but they not do export symbol
ion_page_pool_alloc()
ion_page_pool_free()
ion_page_pool_nr_pages()
ion_page_pool_shrink()
ion_page_pool_create()
ion_page_pool_destroy()

Bug: 158729041
Change-Id: If3897d5e0105edefe03a51ac52c7b3d423aaa988
Signed-off-by: Chao Hao <chao.hao@mediatek.com>
Signed-off-by: Chun-Hung Wu <chun-hung.wu@mediatek.com>
1 file changed
tree: a8d00e1bdf19437f0c2b41363ca15f4f1a9968c6
  1. android/
  2. arch/
  3. block/
  4. certs/
  5. crypto/
  6. Documentation/
  7. drivers/
  8. fs/
  9. include/
  10. init/
  11. ipc/
  12. kernel/
  13. lib/
  14. LICENSES/
  15. mm/
  16. net/
  17. samples/
  18. scripts/
  19. security/
  20. sound/
  21. tools/
  22. usr/
  23. virt/
  24. .clang-format
  25. .cocciconfig
  26. .get_maintainer.ignore
  27. .gitattributes
  28. .gitignore
  29. .mailmap
  30. build.config.aarch64
  31. build.config.allmodconfig
  32. build.config.allmodconfig.aarch64
  33. build.config.allmodconfig.arm
  34. build.config.allmodconfig.x86_64
  35. build.config.arm
  36. build.config.common
  37. build.config.db845c
  38. build.config.gki
  39. build.config.gki-debug.aarch64
  40. build.config.gki-debug.x86_64
  41. build.config.gki.aarch64
  42. build.config.gki.x86_64
  43. build.config.gki_kasan
  44. build.config.gki_kasan.aarch64
  45. build.config.gki_kasan.x86_64
  46. build.config.hikey960
  47. build.config.x86_64
  48. COPYING
  49. CREDITS
  50. Kbuild
  51. Kconfig
  52. MAINTAINERS
  53. Makefile
  54. README
  55. README.md
README.md

How do I submit patches to Android Common Kernels

  1. BEST: Make all of your changes to upstream Linux. If appropriate, backport to the stable releases. These patches will be merged automatically in the corresponding common kernels. If the patch is already in upstream Linux, post a backport of the patch that conforms to the patch requirements below.

  2. LESS GOOD: Develop your patches out-of-tree (from an upstream Linux point-of-view). Unless these are fixing an Android-specific bug, these are very unlikely to be accepted unless they have been coordinated with kernel-team@android.com. If you want to proceed, post a patch that conforms to the patch requirements below.

Common Kernel patch requirements

  • All patches must conform to the Linux kernel coding standards and pass script/checkpatch.pl
  • Patches shall not break gki_defconfig or allmodconfig builds for arm, arm64, x86, x86_64 architectures (see https://source.android.com/setup/build/building-kernels)
  • If the patch is not merged from an upstream branch, the subject must be tagged with the type of patch: UPSTREAM:, BACKPORT:, FROMGIT:, FROMLIST:, or ANDROID:.
  • All patches must have a Change-Id: tag (see https://gerrit-review.googlesource.com/Documentation/user-changeid.html)
  • If an Android bug has been assigned, there must be a Bug: tag.
  • All patches must have a Signed-off-by: tag by the author and the submitter

Additional requirements are listed below based on patch type

Requirements for backports from mainline Linux: UPSTREAM:, BACKPORT:

  • If the patch is a cherry-pick from Linux mainline with no changes at all
    • tag the patch subject with UPSTREAM:.
    • add upstream commit information with a (cherry-picked from ...) line
    • Example:
      • if the upstream commit message is
        important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

    - then Joe Smith would upload the patch for the common kernel as

        UPSTREAM: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        (cherry-picked from c31e73121f4c1ec41143423ac6ce3ce6dafdcec1)
        Signed-off-by: Joe Smith <joe.smith@foo.org>
  • If the patch requires any changes from the upstream version, tag the patch with BACKPORT: instead of UPSTREAM:.
    • use the same tags as UPSTREAM:
    • add comments about the changes under the (cherry-picked from ...) line
    • Example:
        BACKPORT: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        (cherry-picked from c31e73121f4c1ec41143423ac6ce3ce6dafdcec1)
        [ Resolved minor conflict in drivers/foo/bar.c ]
        Signed-off-by: Joe Smith <joe.smith@foo.org>

Requirements for other backports: FROMGIT:, FROMLIST:,

  • If the patch has been merged into an upstream maintainer tree, but has not yet been merged into Linux mainline
    • tag the patch subject with FROMGIT:
    • add info on where the patch came from as (cherry picked from commit <sha1> <repo> <branch>). This must be a stable maintainer branch (not rebased, so don't use linux-next for example).
    • if changes were required, use BACKPORT: FROMGIT:
    • Example:
      • if the commit message in the maintainer tree is
        important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

    - then Joe Smith would upload the patch for the common kernel as

        FROMGIT: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        (cherry picked from commit 878a2fd9de10b03d11d2f622250285c7e63deace
         https://git.kernel.org/pub/scm/linux/kernel/git/foo/bar.git test-branch)
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        Signed-off-by: Joe Smith <joe.smith@foo.org>
  • If the patch has been submitted to LKML, but not accepted into any maintainer tree
    • tag the patch subject with FROMLIST:
    • add a Link: tag with a link to the submittal on lore.kernel.org
    • if changes were required, use BACKPORT: FROMLIST:
    • Example:
        FROMLIST: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        Link: https://lore.kernel.org/lkml/20190619171517.GA17557@someone.com/
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        Signed-off-by: Joe Smith <joe.smith@foo.org>

Requirements for Android-specific patches: ANDROID:

  • If the patch is fixing a bug to Android-specific code
    • tag the patch subject with ANDROID:
    • add a Fixes: tag that cites the patch with the bug
    • Example:
        ANDROID: fix android-specific bug in foobar.c

        This is the detailed description of the important fix

        Fixes: 1234abcd2468 ("foobar: add cool feature")
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        Signed-off-by: Joe Smith <joe.smith@foo.org>
  • If the patch is a new feature
    • tag the patch subject with ANDROID:
    • add a Bug: tag with the Android bug (required for android-specific features)