Thanks. Please also include the note in the final commit message. Reviewed-by: [email protected]
> -----Original Message----- > From: edk2-devel [mailto:[email protected]] On Behalf Of Ard > Biesheuvel > Sent: Wednesday, June 6, 2018 5:10 AM > To: [email protected] > Cc: Ni, Ruiyu <[email protected]>; Ard Biesheuvel > <[email protected]>; > Gao, Liming <[email protected]>; Yao, Jiewen <[email protected]>; Leif > Lindholm <[email protected]>; Kinney, Michael D > <[email protected]>; Zeng, Star <[email protected]> > Subject: Re: [edk2] [PATCH] MdeModulePkg/CapsulePei: clean Dcache before > consuming capsule data > > On 6 June 2018 at 11:52, Ard Biesheuvel <[email protected]> wrote: > > When capsule updates are staged for processing after a warm reboot, > > they are copied into memory with the MMU and caches enabled. When > > the capsule PEI gets around to coalescing the capsule, the MMU and > > caches may still be disabled, and so on architectures where uncached > > accesses are incoherent with the caches (such as ARM and AARCH64), > > we may read stale data if we don't clean the caches to memory first. > > > > Contributed-under: TianoCore Contribution Agreement 1.1 > > Signed-off-by: Ard Biesheuvel <[email protected]> > > Leif asked me to include a note why this cannot be done when > UpdateCapsule() is called. > > > """ > Note that this cache maintenance cannot be done during the invocation > of UpdateCapsule(), since the ScatterGatherList structures are only > identified by physical address, and at runtime, the firmware doesn't > know whether and where this memory is mapped, and cache maintenance > requires a virtual address. > """ > > > --- > > MdeModulePkg/Universal/CapsulePei/CapsulePei.inf | 1 + > > MdeModulePkg/Universal/CapsulePei/Common/CapsuleCoalesce.c | 4 ++++ > > 2 files changed, 5 insertions(+) > > > > diff --git a/MdeModulePkg/Universal/CapsulePei/CapsulePei.inf > b/MdeModulePkg/Universal/CapsulePei/CapsulePei.inf > > index c54bc21a95a8..594e110d1f8a 100644 > > --- a/MdeModulePkg/Universal/CapsulePei/CapsulePei.inf > > +++ b/MdeModulePkg/Universal/CapsulePei/CapsulePei.inf > > @@ -48,6 +48,7 @@ [Packages] > > > > [LibraryClasses] > > BaseLib > > + CacheMaintenanceLib > > HobLib > > BaseMemoryLib > > PeiServicesLib > > diff --git a/MdeModulePkg/Universal/CapsulePei/Common/CapsuleCoalesce.c > b/MdeModulePkg/Universal/CapsulePei/Common/CapsuleCoalesce.c > > index 3e7054cd38a9..1730f925adc5 100644 > > --- a/MdeModulePkg/Universal/CapsulePei/Common/CapsuleCoalesce.c > > +++ b/MdeModulePkg/Universal/CapsulePei/Common/CapsuleCoalesce.c > > @@ -27,6 +27,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY > KIND, EITHER EXPRESS OR IMPLIED. > > #include <Guid/CapsuleVendor.h> > > > > #include <Library/BaseMemoryLib.h> > > +#include <Library/CacheMaintenanceLib.h> > > #include <Library/DebugLib.h> > > #include <Library/PrintLib.h> > > #include <Library/BaseLib.h> > > @@ -283,6 +284,9 @@ ValidateCapsuleByMemoryResource ( > > DEBUG ((EFI_D_INFO, "Address(0x%lx) Size(0x%lx) in > MemoryResource[0x%x] - Start(0x%lx) Length(0x%lx)\n", > > Address, Size, > > Index, MemoryResource[Index].PhysicalStart, > MemoryResource[Index].ResourceLength)); > > + > > + WriteBackDataCacheRange ((VOID *)(UINTN)Address, Size); > > + > > return TRUE; > > } > > } > > -- > > 2.17.0 > > > _______________________________________________ > edk2-devel mailing list > [email protected] > https://lists.01.org/mailman/listinfo/edk2-devel _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
