[PATCH v7 04/16] arm64: kvm: Move the do_el2_call macro to a header file
james.morse at arm.com
Tue Apr 19 08:05:02 PDT 2016
On 19/04/16 16:02, Marc Zyngier wrote:
> On 01/04/16 17:53, James Morse wrote:
>> diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h
>> index 9f22dd607958..b8fdddeca71b 100644
>> --- a/arch/arm64/include/asm/virt.h
>> +++ b/arch/arm64/include/asm/virt.h
>> @@ -21,7 +21,23 @@
>> #define BOOT_CPU_MODE_EL1 (0xe11)
>> #define BOOT_CPU_MODE_EL2 (0xe12)
>> -#ifndef __ASSEMBLY__
>> +#ifdef __ASSEMBLY__
>> +.macro do_el2_call
>> + /*
>> + * Shuffle the parameters before calling the function
>> + * pointed to in x0. Assumes parameters in x[1,2,3].
>> + */
>> + sub sp, sp, #16
>> + str lr, [sp]
>> + mov lr, x0
>> + mov x0, x1
>> + mov x1, x2
>> + mov x2, x3
>> + blr lr
>> + ldr lr, [sp]
>> + add sp, sp, #16
> So while I'm not opposed to this macro being reused, the name is
> slightly misleading out of the original context. This macro doesn't take
> you to EL2, but implements a very peculiar calling convention that only
> the HYP code is expecting.
Ah, I hadn't thought of it like that!
> Could we have a disclaimer saying something along the lines of "Don't
> you dare using this macro!"?
Or rename it? Something like 'unpack_el2_call'.
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