[Intel-gfx] [RFC 3/9] staging/android/sync: Move sync framework out of staging

[Gustavo Padovan]

2016-01-13 John.C.Harrison at Intel.com <John.C.Harrison at Intel.com>:

> From: John Harrison <John.C.Harrison at Intel.com>
> 
> The sync framework is now used by the i915 driver. Therefore it can be
> moved out of staging and into the regular tree. Also, the public
> interfaces can actually be made public and exported.
> 
> v0.3: New patch for series.
> 
> Signed-off-by: John Harrison <John.C.Harrison at Intel.com>
> Signed-off-by: Geoff Miller <geoff.miller at intel.com>
> Cc: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
> Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> Cc: Arve Hjønnevåg <arve at android.com>
> Cc: Riley Andrews <riandrews at android.com>
> ---
>  drivers/android/Kconfig                |  28 ++
>  drivers/android/Makefile               |   2 +
>  drivers/android/sw_sync.c              | 260 ++++++++++++
>  drivers/android/sw_sync.h              |  59 +++
>  drivers/android/sync.c                 | 734 +++++++++++++++++++++++++++++++++
>  drivers/android/sync.h                 | 366 ++++++++++++++++
>  drivers/android/sync_debug.c           | 255 ++++++++++++
>  drivers/android/trace/sync.h           |  82 ++++
>  drivers/staging/android/Kconfig        |  28 --
>  drivers/staging/android/Makefile       |   2 -
>  drivers/staging/android/sw_sync.c      | 260 ------------
>  drivers/staging/android/sw_sync.h      |  59 ---
>  drivers/staging/android/sync.c         | 734 ---------------------------------
>  drivers/staging/android/sync.h         | 366 ----------------
>  drivers/staging/android/sync_debug.c   | 255 ------------
>  drivers/staging/android/trace/sync.h   |  82 ----
>  drivers/staging/android/uapi/sw_sync.h |  32 --
>  drivers/staging/android/uapi/sync.h    |  97 -----
>  include/uapi/Kbuild                    |   1 +
>  include/uapi/sync/Kbuild               |   3 +
>  include/uapi/sync/sw_sync.h            |  32 ++
>  include/uapi/sync/sync.h               |  97 +++++
>  22 files changed, 1919 insertions(+), 1915 deletions(-)
>  create mode 100644 drivers/android/sw_sync.c
>  create mode 100644 drivers/android/sw_sync.h
>  create mode 100644 drivers/android/sync.c
>  create mode 100644 drivers/android/sync.h
>  create mode 100644 drivers/android/sync_debug.c
>  create mode 100644 drivers/android/trace/sync.h
>  delete mode 100644 drivers/staging/android/sw_sync.c
>  delete mode 100644 drivers/staging/android/sw_sync.h
>  delete mode 100644 drivers/staging/android/sync.c
>  delete mode 100644 drivers/staging/android/sync.h
>  delete mode 100644 drivers/staging/android/sync_debug.c
>  delete mode 100644 drivers/staging/android/trace/sync.h
>  delete mode 100644 drivers/staging/android/uapi/sw_sync.h
>  delete mode 100644 drivers/staging/android/uapi/sync.h
>  create mode 100644 include/uapi/sync/Kbuild
>  create mode 100644 include/uapi/sync/sw_sync.h
>  create mode 100644 include/uapi/sync/sync.h
> 
> diff --git a/drivers/android/Kconfig b/drivers/android/Kconfig
> index bdfc6c6..9edcd8f 100644
> --- a/drivers/android/Kconfig
> +++ b/drivers/android/Kconfig
> @@ -32,6 +32,34 @@ config ANDROID_BINDER_IPC_32BIT
>  
>  	  Note that enabling this will break newer Android user-space.
>  
> +config SYNC
> +	bool "Synchronization framework"
> +	default n
> +	select ANON_INODES
> +	select DMA_SHARED_BUFFER
> +	---help---
> +	  This option enables the framework for synchronization between multiple
> +	  drivers.  Sync implementations can take advantage of hardware
> +	  synchronization built into devices like GPUs.
> +
> +config SW_SYNC
> +	bool "Software synchronization objects"
> +	default n
> +	depends on SYNC
> +	---help---
> +	  A sync object driver that uses a 32bit counter to coordinate
> +	  synchronization.  Useful when there is no hardware primitive backing
> +	  the synchronization.
> +
> +config SW_SYNC_USER
> +	bool "Userspace API for SW_SYNC"
> +	default n
> +	depends on SW_SYNC
> +	---help---
> +	  Provides a user space API to the sw sync object.
> +	  *WARNING* improper use of this can result in deadlocking kernel
> +	  drivers from userspace.

Also, SW_SYNC_USER is a way too dangerous to be upstreamed a /dev file
because as the warning says it can deadlock the kernel. What I did in my
patches was to move the sw_sync_user features to a debugfs file.

	Gustavo