On 03.03.2016 00:23, David Gibson wrote:
> On Wed, 2 Mar 2016 11:07:55 +0100
> Laurent Vivier <lvivier@xxxxxxxxxx> wrote:
>
>> On 02/03/2016 09:40, Thomas Huth wrote:
>>> Introduce a test for sPAPR hypercalls, starting with the
>>> three hypercalls H_SET_SPRG0, H_PAGE_INIT and H_RANDOM.
>>>
>>> Signed-off-by: Thomas Huth <thuth@xxxxxxxxxx>
>>> ---
...
>>> +static int h_random(uint64_t *val)
>>> +{
>>> + register uint64_t r3 asm("r3") = H_RANDOM;
>>> + register uint64_t r4 asm("r4");
>>> +
>>> + asm volatile (" sc 1 " : "+r"(r3), "=r"(r4) : "r"(r3));
>>
>> as you use "+r" with r3 in the output operands field, I think you don't
>> have to declare it in the input operands field.
>
> More importantly, I think a hypercall is allowed to clobber any of the
> volatile registers (r0 & r3..r12), so they probably need to be declared
> in the clobbers as well.
Ok, that's a point ... I'll fix it up and send a v4.
Thomas
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