Re: [PATCH] ArmPkg/ArmMmuLib: Add new attribute WRITE_BACK_NONSHAREABLE

[Heyi Guo <heyi.guo@linaro.org>]

Thanks,

Heyi


在 11/7/2017 9:30 PM, Ard Biesheuvel 写道:
> On 7 November 2017 at 13:29, Leif Lindholm <leif.lindholm@linaro.org> wrote:
>> On Tue, Nov 07, 2017 at 01:22:19PM +0000, Ard Biesheuvel wrote:
>>> On 7 November 2017 at 12:56, Heyi Guo <heyi.guo@linaro.org> wrote:
>>>> From: Peicong Li <lipeicong@huawei.com>
>>>>
>>>> Flash region needs to be set as cacheable (write back) to increase
>>>> performance, if PEI is still XIP on flash or DXE FV is decompressed
>>>> from flash FV. However some ARM platforms do not support to set flash
>>>> as inner shareable since flash is not normal DDR memory and it will
>>>> not respond to cache snoop request, which will causes system hang
>>>> after MMU is enabled.
>>>>
>>>> So we need a new ARM memory region attribute WRITE_BACK_NONSHAREABLE
>>>> for flash region on these platforms specifically. This attribute will
>>>> set the region as write back but not inner shared.
>>>>
>>>> Contributed-under: TianoCore Contribution Agreement 1.1
>>>> Signed-off-by: Peicong Li <lipeicong@huawei.com>
>>>> Signed-off-by: Heyi Guo <heyi.guo@linaro.org>
>>>> Cc: Leif Lindholm <leif.lindholm@linaro.org>
>>>> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>>> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>> Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
>>
> Pushed as 829633e3a82d. Thanks!
>
>>>> ---
>>>>   ArmPkg/Include/Library/ArmLib.h                  | 7 +++++++
>>>>   ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c | 4 ++++
>>>>   2 files changed, 11 insertions(+)
>>>>
>>>> diff --git a/ArmPkg/Include/Library/ArmLib.h b/ArmPkg/Include/Library/ArmLib.h
>>>> index 24ffe9f..38199be 100644
>>>> --- a/ArmPkg/Include/Library/ArmLib.h
>>>> +++ b/ArmPkg/Include/Library/ArmLib.h
>>>> @@ -41,6 +41,13 @@ typedef enum {
>>>>     ARM_MEMORY_REGION_ATTRIBUTE_NONSECURE_UNCACHED_UNBUFFERED,
>>>>     ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK,
>>>>     ARM_MEMORY_REGION_ATTRIBUTE_NONSECURE_WRITE_BACK,
>>>> +  // On some platforms, memory mapped flash region is designed as not supporting
>>>> +  // shareable attribute, so WRITE_BACK_NONSHAREABLE is added for such special
>>>> +  // need.
>>>> +  // Do NOT use below two attributes if you are not sure.
>>>> +  ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK_NONSHAREABLE,
>>>> +  ARM_MEMORY_REGION_ATTRIBUTE_NONSECURE_WRITE_BACK_NONSHAREABLE,
>>>> +
>>>>     ARM_MEMORY_REGION_ATTRIBUTE_WRITE_THROUGH,
>>>>     ARM_MEMORY_REGION_ATTRIBUTE_NONSECURE_WRITE_THROUGH,
>>>>     ARM_MEMORY_REGION_ATTRIBUTE_DEVICE,
>>>> diff --git a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
>>>> index 8bd1c6f..4b62ecb 100644
>>>> --- a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
>>>> +++ b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
>>>> @@ -35,6 +35,10 @@ ArmMemoryAttributeToPageAttribute (
>>>>     )
>>>>   {
>>>>     switch (Attributes) {
>>>> +  case ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK_NONSHAREABLE:
>>>> +  case ARM_MEMORY_REGION_ATTRIBUTE_NONSECURE_WRITE_BACK_NONSHAREABLE:
>>>> +    return TT_ATTR_INDX_MEMORY_WRITE_BACK;
>>>> +
>>>>     case ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK:
>>>>     case ARM_MEMORY_REGION_ATTRIBUTE_NONSECURE_WRITE_BACK:
>>>>       return TT_ATTR_INDX_MEMORY_WRITE_BACK | TT_SH_INNER_SHAREABLE;
>>>> --
>>>> 2.7.2.windows.1
>>>>