| Message ID | 1461077734-4327-3-git-send-email-ard.biesheuvel@linaro.org |
|---|---|
| State | Accepted |
| Commit | 885d57ef091fd58916163e79ee694ddaf8fcc25e |
| Headers | show |
On Tue, Apr 19, 2016 at 04:55:32PM +0200, Ard Biesheuvel wrote: > Comparing a GCD attribute field directly against EFI_MEMORY_UC and > EFI_MEMORY_WT is incorrect, since it may have other bits set as well > which are not related to the cacheability of the region. So instead, > test explicitly against the flags EFI_MEMORY_WB and EFI_MEMORY_WT, > which must be set if the region may be mapped with cacheable attributes. > > Contributed-under: TianoCore Contribution Agreement 1.0 > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Whoops. Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org> > --- > ArmPkg/Library/ArmDmaLib/ArmDmaLib.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c b/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c > index 834afdba10ef..7f6598318a91 100644 > --- a/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c > +++ b/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c > @@ -101,9 +101,7 @@ DmaMap ( > } > > // If the mapped buffer is not an uncached buffer > - if ( (GcdDescriptor.Attributes != EFI_MEMORY_WC) && > - (GcdDescriptor.Attributes != EFI_MEMORY_UC) ) > - { > + if ((GcdDescriptor.Attributes & (EFI_MEMORY_WB | EFI_MEMORY_WT)) != 0) { > // > // If the buffer does not fill entire cache lines we must double buffer into > // uncached memory. Device (PCI) address becomes uncached page. > -- > 2.5.0 > _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
diff --git a/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c b/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c index 834afdba10ef..7f6598318a91 100644 --- a/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c +++ b/ArmPkg/Library/ArmDmaLib/ArmDmaLib.c @@ -101,9 +101,7 @@ DmaMap ( } // If the mapped buffer is not an uncached buffer - if ( (GcdDescriptor.Attributes != EFI_MEMORY_WC) && - (GcdDescriptor.Attributes != EFI_MEMORY_UC) ) - { + if ((GcdDescriptor.Attributes & (EFI_MEMORY_WB | EFI_MEMORY_WT)) != 0) { // // If the buffer does not fill entire cache lines we must double buffer into // uncached memory. Device (PCI) address becomes uncached page.
Comparing a GCD attribute field directly against EFI_MEMORY_UC and EFI_MEMORY_WT is incorrect, since it may have other bits set as well which are not related to the cacheability of the region. So instead, test explicitly against the flags EFI_MEMORY_WB and EFI_MEMORY_WT, which must be set if the region may be mapped with cacheable attributes. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- ArmPkg/Library/ArmDmaLib/ArmDmaLib.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) -- 2.5.0 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel