On Mär 29 2021, Christophe Leroy wrote:
> Le 29/03/2021 à 10:33, Benjamin Herrenschmidt a écrit :
>> On Fri, 2021-03-12 at 11:20 +1000, Nicholas Piggin wrote:
>>>
>>> +static inline void nap_adjust_return(struct pt_regs *regs)
>>>
>>> +{
>>>
>>> +#ifdef CONFIG_PPC_970_NAP
>>>
>>> + if (unlikely(test_thread_local_flags(_TLF_NAPPING))) {
>>> + /* Can avoid a test-and-clear because NMIs do not call this
>>> */
>>> + clear_thread_local_flags(_TLF_NAPPING);
>>> + regs->nip = (unsigned long)power4_idle_nap_return;
>>> + }
>> Is this a pointer to a function descriptor or the actual code ?
>>
>
> --- a/arch/powerpc/kernel/idle_book3s.S
> +++ b/arch/powerpc/kernel/idle_book3s.S
> @@ -209,4 +209,8 @@ _GLOBAL(power4_idle_nap)
> mtmsrd r7
> isync
> b 1b
> +
> + .globl power4_idle_nap_return
> +power4_idle_nap_return:
> + blr
> #endif
The problem is not the definition, it is the reference. In C, a
function symbol always resolves to the address of the descriptor.
Andreas.
--
Andreas Schwab, sch...@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
"And now for something completely different."
