Excerpts from Pratik Rajesh Sampat's message of July 18, 2020 4:53 am:
> As the idle framework's architecture is incomplete, hence instead of
> checking for just the processor type advertised in the device tree CPU
> features; check for the Processor Version Register (PVR) so that finer
> granularity can be leveraged while making processor checks.
>
> Signed-off-by: Pratik Rajesh Sampat <psam...@linux.ibm.com>
> ---
> arch/powerpc/platforms/powernv/idle.c | 14 +++++++-------
> 1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powernv/idle.c
> b/arch/powerpc/platforms/powernv/idle.c
> index 2dd467383a88..f62904f70fc6 100644
> --- a/arch/powerpc/platforms/powernv/idle.c
> +++ b/arch/powerpc/platforms/powernv/idle.c
> @@ -92,7 +92,7 @@ static int pnv_save_sprs_for_deep_states(void)
> if (rc != 0)
> return rc;
>
> - if (cpu_has_feature(CPU_FTR_ARCH_300)) {
> + if (pvr_version_is(PVR_POWER9)) {
> rc = opal_slw_set_reg(pir, P9_STOP_SPR_MSR, msr_val);
> if (rc)
> return rc;
> @@ -116,7 +116,7 @@ static int pnv_save_sprs_for_deep_states(void)
> return rc;
>
> /* Only p8 needs to set extra HID regiters */
> - if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
> + if (!pvr_version_is(PVR_POWER9)) {
>
> rc = opal_slw_set_reg(pir, SPRN_HID1, hid1_val);
> if (rc != 0)
What I think you should do is keep using CPU_FTR_ARCH_300 for this stuff
which is written for power9 and we know is running on power9, because
that's a faster test (static branch and does not have to read PVR. And
then...
> @@ -1205,7 +1205,7 @@ static void __init pnv_probe_idle_states(void)
> return;
> }
>
> - if (cpu_has_feature(CPU_FTR_ARCH_300))
> + if (pvr_version_is(PVR_POWER9))
> pnv_power9_idle_init();
>
> for (i = 0; i < nr_pnv_idle_states; i++)
Here is where you would put the version check. Once we have code that
can also handle P10 (either by testing CPU_FTR_ARCH_31, or by adding
an entirely new power10 idle function), then you can add the P10 version
check here.
Thanks,
Nick
