> On Jul 14, 2023, at 3:55 AM, Alexandru Elisei <alexandru.elisei@xxxxxxx> wrote:
>
> !! External Email
>
> Hi,
>
> On Sat, Jun 17, 2023 at 01:31:38AM +0000, Nadav Amit wrote:
>> From: Nadav Amit <namit@xxxxxxxxxx>
>>
>> While no real problem was encountered, having an inline assembly without
>> volatile keyword and output can allow the compiler to ignore it. And
>> without a memory clobber, potentially reorder it.
>>
>> Add volatile and memory clobber.
>>
>> Signed-off-by: Nadav Amit <namit@xxxxxxxxxx>
>> ---
>> lib/arm64/asm/mmu.h | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/lib/arm64/asm/mmu.h b/lib/arm64/asm/mmu.h
>> index 5c27edb..cf94403 100644
>> --- a/lib/arm64/asm/mmu.h
>> +++ b/lib/arm64/asm/mmu.h
>> @@ -14,7 +14,7 @@
>> static inline void flush_tlb_all(void)
>> {
>> dsb(ishst);
>> - asm("tlbi vmalle1is");
>
> From the gas manual [1]:
>
> "asm statements that have no output operands and asm goto statements, are
> implicitly volatile."
>
> Looks to me like both TLBIs fall into this category.
>
> And I think the "memory" clobber is not needed because the dsb macro before and
> after the TLBI already have it.
You are completely correct. I forgot about the implicit “volatile”.
This one can be dropped.
