Messages in this thread | | | Date | Mon, 22 Aug 2016 14:43:14 +0100 | From | Will Deacon <> | Subject | Re: [PATCH 1/2] arm64: kernel: Add SMC Session ID to results |
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On Sat, Aug 20, 2016 at 12:51:13AM -0500, Andy Gross wrote: > This patch adds the SMC Session ID to the results passed back from SMC > calls. The Qualcomm SMC implementation provides for interrupted SMC > functions. When this occurs, the SMC call will return a session ID that > is required to be used when resuming the interrupted SMC call. > > Signed-off-by: Andy Gross <andy.gross@linaro.org> > --- > arch/arm64/kernel/asm-offsets.c | 1 + > arch/arm64/kernel/smccc-call.S | 1 + > include/linux/arm-smccc.h | 4 +++- > 3 files changed, 5 insertions(+), 1 deletion(-)
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> diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h > index b5abfda..82d919f 100644 > --- a/include/linux/arm-smccc.h > +++ b/include/linux/arm-smccc.h > @@ -63,18 +63,20 @@ > /** > * struct arm_smccc_res - Result from SMC/HVC call > * @a0-a3 result values from registers 0 to 3 > + * @a6 Session ID register (optional) > */ > struct arm_smccc_res { > unsigned long a0; > unsigned long a1; > unsigned long a2; > unsigned long a3; > + unsigned long a6; > }; > > /** > * arm_smccc_smc() - make SMC calls > * @a0-a7: arguments passed in registers 0 to 7 > - * @res: result values from registers 0 to 3 > + * @res: result values from registers 0 to 3 and optional register 6
AFAICT from reading the SMCCC spec, parameter register 6 is "Unpredictable, Scratch registers" in return state, so I don't think this is correct.
What am I missing?
Will
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