Re: [edk2] [PATCH] ArmPkg/ArmDmaLib: use double buffering only for bus master write

2017-08-17 Thread Leif Lindholm
On Thu, Aug 17, 2017 at 01:45:58PM +0100, Ard Biesheuvel wrote: > On 17 August 2017 at 13:43, Leif Lindholm wrote: > > On Thu, Aug 17, 2017 at 01:25:46PM +0100, Ard Biesheuvel wrote: > >> The ArmPkg implementation of DmaLib uses double buffering to ensure > >> that any

Re: [edk2] [PATCH] ArmPkg/ArmDmaLib: use double buffering only for bus master write

2017-08-17 Thread Ard Biesheuvel
On 17 August 2017 at 13:43, Leif Lindholm wrote: > On Thu, Aug 17, 2017 at 01:25:46PM +0100, Ard Biesheuvel wrote: >> The ArmPkg implementation of DmaLib uses double buffering to ensure >> that any attempt to perform non-coherent DMA on unaligned buffers cannot >>

Re: [edk2] [PATCH] ArmPkg/ArmDmaLib: use double buffering only for bus master write

2017-08-17 Thread Leif Lindholm
On Thu, Aug 17, 2017 at 01:25:46PM +0100, Ard Biesheuvel wrote: > The ArmPkg implementation of DmaLib uses double buffering to ensure > that any attempt to perform non-coherent DMA on unaligned buffers cannot > corrupt adjacent unrelated data which happens to share cachelines with > the data we

Re: [edk2] [PATCH] ArmPkg/ArmDmaLib: use double buffering only for bus master write

2017-08-17 Thread Ard Biesheuvel
On 17 August 2017 at 13:25, Ard Biesheuvel wrote: > The ArmPkg implementation of DmaLib uses double buffering to ensure > that any attempt to perform non-coherent DMA on unaligned buffers cannot > corrupt adjacent unrelated data which happens to share cachelines with >

[edk2] [PATCH] ArmPkg/ArmDmaLib: use double buffering only for bus master write

2017-08-17 Thread Ard Biesheuvel
The ArmPkg implementation of DmaLib uses double buffering to ensure that any attempt to perform non-coherent DMA on unaligned buffers cannot corrupt adjacent unrelated data which happens to share cachelines with the data we are exchanging with the device. Such corruption can only occur on bus