Messages in this thread |  | | Date | Mon, 14 Aug 2017 12:14:09 -0700 | From | Sukadev Bhattiprolu <> | Subject | Re: [PATCH v6 01/17] powerpc/vas: Define macros, register fields and structures |
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Nicholas Piggin [npiggin@gmail.com] wrote: > On Mon, 14 Aug 2017 15:21:48 +1000 > Michael Ellerman <mpe@ellerman.id.au> wrote: > > > Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> writes: > > > > arch/powerpc/include/asm/vas.h | 35 ++++ > > > arch/powerpc/include/uapi/asm/vas.h | 25 +++ > > > > I thought we weren't exposing VAS to userspace yet? > > > > If we are then we need to get things straight WRT copy/paste abort. >
> No we should not be. This might be just a leftover hunk that should > be moved to a future series.
Yes, I should have posted patches 14..17 separately as an RFC that goes on top of the VAS kernel patches 1..13.
> > At the moment (as far as I understand) it should be limited to > preempt-disabled, process context, kernel users which avoids any > concern for switch_to. >
In the FTW case, there is no data transfer from user space to the hardware. i.e the copy/paste submit a NULL CRB and hardware will be configured (see ->fifo_disable setting in winctx) to ignore any data they specify in the CRB.
Would we be able to allow copy/paste from user space in that case?
Sukadev
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