Hi Nicholas, On Fri, Jul 07, 2017 at 01:06:46AM +1000, Nicholas Piggin wrote: > On Wed, 5 Jul 2017 22:08:14 +0530 > "Gautham R. Shenoy" <e...@linux.vnet.ibm.com> wrote: > > > From: "Gautham R. Shenoy" <e...@linux.vnet.ibm.com> > > > > In this patch we define a new function named pnv_power8_idle_init(). > > > > We move the following code from pnv_init_idle_states() into this newly > > defined function. > > a) That patches out pnv_fastsleep_workaround_at_entry/exit when > > no states with OPAL_PM_SLEEP_ENABLED_ER1 are present. > > b) Creating a sysfs control to choose how the workaround has to be > > applied when a OPAL_PM_SLEEP_ENABLED_ER1 state is present. > > c) Set ppc_md.power_save to power7_idle when OPAL_PM_NAP_ENABLED is > > present. > > > > With this, all the power8 specific initializations are in one place. > > > > Signed-off-by: Gautham R. Shenoy <e...@linux.vnet.ibm.com> > > --- > > arch/powerpc/platforms/powernv/idle.c | 59 > > ++++++++++++++++++++++++----------- > > 1 file changed, 40 insertions(+), 19 deletions(-) > > > > diff --git a/arch/powerpc/platforms/powernv/idle.c > > b/arch/powerpc/platforms/powernv/idle.c > > index a5990d9..c400ff9 100644 > > --- a/arch/powerpc/platforms/powernv/idle.c > > +++ b/arch/powerpc/platforms/powernv/idle.c > > @@ -564,6 +564,44 @@ static void __init pnv_power9_idle_init(void) > > pnv_first_deep_stop_state); > > } > > > > + > > +static void __init pnv_power8_idle_init(void) > > +{ > > + int i; > > + bool has_nap = false; > > + bool has_sleep_er1 = false; > > + int dt_idle_states = pnv_idle.nr_states; > > + > > + for (i = 0; i < dt_idle_states; i++) { > > + struct pnv_idle_state *state = &pnv_idle.states[i]; > > + > > + if (state->flags & OPAL_PM_NAP_ENABLED) > > + has_nap = true; > > + if (state->flags & OPAL_PM_SLEEP_ENABLED_ER1) > > + has_sleep_er1 = true; > > + } > > + > > + if (!has_sleep_er1) { > > + patch_instruction( > > + (unsigned int *)pnv_fastsleep_workaround_at_entry, > > + PPC_INST_NOP); > > + patch_instruction( > > + (unsigned int *)pnv_fastsleep_workaround_at_exit, > > + PPC_INST_NOP); > > + } else { > > + /* > > + * OPAL_PM_SLEEP_ENABLED_ER1 is set. It indicates that > > + * workaround is needed to use fastsleep. Provide sysfs > > + * control to choose how this workaround has to be applied. > > + */ > > + device_create_file(cpu_subsys.dev_root, > > + &dev_attr_fastsleep_workaround_applyonce); > > + } > > + > > + if (has_nap) > > + ppc_md.power_save = power7_idle; > > +} > > + > > /* > > * Returns 0 if prop1_len == prop2_len. Else returns -1 > > */ > > @@ -837,6 +875,8 @@ static int __init pnv_probe_idle_states(void) > > > > if (cpu_has_feature(CPU_FTR_ARCH_300)) > > pnv_power9_idle_init(); > > + else > > + pnv_power8_idle_init(); > > > > for (i = 0; i < dt_idle_states; i++) { > > if (!pnv_idle.states[i].valid) > > @@ -858,22 +898,6 @@ static int __init pnv_init_idle_states(void) > > if (pnv_probe_idle_states()) > > goto out; > > > > - if (!(supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED_ER1)) { > > - patch_instruction( > > - (unsigned int *)pnv_fastsleep_workaround_at_entry, > > - PPC_INST_NOP); > > - patch_instruction( > > - (unsigned int *)pnv_fastsleep_workaround_at_exit, > > - PPC_INST_NOP); > > So previously this would run on POWER9 and patch out those branches. > But POWER9 never runs that code, so no problem. Good cleanup.
And that's what I thought, but on checking the assembly code, I found that pnv_fastsleep_workaround_at_exit is executed on POWER9. Will fix this! > > Reviewed-by: Nicholas Piggin <npig...@gmail.com> > -- Thanks and Regards gautham.