Re: [PATCH 0/5] ArmPkg et al: remove UncachedMemoryallocationLib

[Leif Lindholm <leif.lindholm@linaro.org>]

On Fri, Aug 25, 2017 at 01:10:09PM +0100, Ard Biesheuvel wrote:
> This series is a followup to 'ArmPkg/ArmDmaLib: remove dependency on
> UncachedMemoryAllocationLib' sent out yesterday, and removes library
> entirely.
> 
> There are two reasons for this:
> - UncachedMemoryAllocationLib is often abused by drivers that should
>   be using DMA abstractions instead. It is up to the platform to decide
>   whether DMA is cache coherent or not, and the fact that non-cache
>   coherent DMA may be implemented using uncached allocations should remain
>   an implementation detail of the DmaLib instance.
> 
> - The code is poorly maintained, only frees its allocations in the destructor,
>   and misleads by exposing pool allocate/free entry points that are actually
>   backed by page based allocations.
> 
> Patches #1 and #2 add a DmaAllocateAlignedBuffer() to DmaLib and both
> its implementations. This is required for current users of
> UncachedMemoryAllocationLib that rely on minimum alignment to be able
> to switch the DmaLib.
> 
> Patches #3 and #4 remove a couple of stale references.
> 
> Patch #5 actually removes the library and its single remaining implementation.

For the series:
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

However, this breaks a bunch of (edk2-)platforms: juno, fvp, tc2,
hikey and armada70x0. Is there a follow-on patch coming for those,
and could you hold off on pushing this series until that is ready?

Armada has the only non-bogus UncachedMemoryAllocationLib dependency,
the others are just trivial deletions.

/
    Leif

> Ard Biesheuvel (5):
>   EmbeddedPkg/DmaLib: add routine to allocate aligned buffers
>   ArmPkg/ArmDmaLib: implement DmaAllocateAlignedBuffer()
>   BeagleBoardPkg: remove UncachedMemoryAllocationLib resolutions
>   Omap35xxPkg: remove bogus UncachedMemoryAllocationLib dependency
>   ArmPkg: remove UncachedMemoryAllocationLib
> 
>  ArmPkg/ArmPkg.dec                                                          |   4 -
>  ArmPkg/ArmPkg.dsc                                                          |   2 -
>  ArmPkg/Include/Library/UncachedMemoryAllocationLib.h                       | 665 ------------------
>  ArmPkg/Library/ArmDmaLib/ArmDmaLib.c                                       |  42 +-
>  ArmPkg/Library/UncachedMemoryAllocationLib/UncachedMemoryAllocationLib.c   | 719 --------------------
>  ArmPkg/Library/UncachedMemoryAllocationLib/UncachedMemoryAllocationLib.inf |  50 --
>  BeagleBoardPkg/BeagleBoardPkg.dsc                                          |   2 -
>  EmbeddedPkg/Include/Library/DmaLib.h                                       |  30 +-
>  EmbeddedPkg/Library/NullDmaLib/NullDmaLib.c                                |  48 +-
>  Omap35xxPkg/Library/DebugAgentTimerLib/DebugAgentTimerLib.inf              |   1 +
>  Omap35xxPkg/Library/OmapDmaLib/OmapDmaLib.inf                              |   1 -
>  Omap35xxPkg/Omap35xxPkg.dsc                                                |   2 -
>  12 files changed, 112 insertions(+), 1454 deletions(-)
>  delete mode 100644 ArmPkg/Include/Library/UncachedMemoryAllocationLib.h
>  delete mode 100644 ArmPkg/Library/UncachedMemoryAllocationLib/UncachedMemoryAllocationLib.c
>  delete mode 100644 ArmPkg/Library/UncachedMemoryAllocationLib/UncachedMemoryAllocationLib.inf
> 
> -- 
> 2.11.0
>