Re: [PATCHv5 3/4] tracing: Add register read/write tracing support

From: Arnd Bergmann
Date: Mon Dec 06 2021 - 05:46:45 EST


On Mon, Dec 6, 2021 at 11:11 AM Sai Prakash Ranjan
<quic_saipraka@xxxxxxxxxxx> wrote:
> On 12/6/2021 2:29 PM, Arnd Bergmann wrote:
> > On Mon, Dec 6, 2021 at 9:28 AM Sai Prakash Ranjan
> >> +void log_read_mmio(u8 width, const volatile void __iomem *addr)
> >> +{
> >> + trace_rwmmio_read(CALLER_ADDR0, CALLER_ADDR1, width, addr);
> >> +}
> > Here, it may be better to pass the caller address as an argument, I think
> > CALLER_ADDR1 is not always reliable, though it's possible that it is
> > in the configurations when this file gets enabled.
> >
> >
>
> Do you mean that we use __builtin_return_address(0,1) directly here or
> that I pass __func__ as the argument to log_read/write_mmio or is there
> some other way to pass the caller address?

I meant passing CALLER_ADDR0 from readl() down to
log_read_mmio().

Arnd