| Message ID | 84bfbacbd0ab98dd82241292a29e4d5d1bb456c6.1490024477.git.ego@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
On Mon, 20 Mar 2017 21:24:17 +0530 "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> wrote: > From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> > > Currently during idle-init on power9, if we don't find suitable stop > states in the device tree that can be used as the > default_stop/deepest_stop, we set stop0 (ESL=1,EC=1) as the default > stop state psscr to be used by power9_idle and deepest stop state > which is used by CPU-Hotplug. > > However, if the platform firmware has not configured or enabled a stop > state, the kernel should not make any assumptions and fallback to a > default choice. > > If the kernel uses a stop state that is not configured by the platform > firmware, it may lead to further failures which should be avoided. > > In this patch, we modify the init code to ensure that the kernel uses > only the stop states exposed by the firmware through the device > tree. When a suitable default stop state isn't found, we disable > ppc_md.power_save for power9. Similarly, when a suitable > deepest_stop_state is not found in the device tree exported by the > firmware, fall back to the default busy-wait loop in the CPU-Hotplug > code. > > [Changelog written with inputs from svaidy@linux.vnet.ibm.com] > > Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> > --- > arch/powerpc/platforms/powernv/idle.c | 35 ++++++++++++++++++----------------- > 1 file changed, 18 insertions(+), 17 deletions(-) > > diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c > index f335e0f..63ade78 100644 > --- a/arch/powerpc/platforms/powernv/idle.c > +++ b/arch/powerpc/platforms/powernv/idle.c > @@ -147,7 +147,6 @@ u32 pnv_get_supported_cpuidle_states(void) > } > EXPORT_SYMBOL_GPL(pnv_get_supported_cpuidle_states); > > - > static void pnv_fastsleep_workaround_apply(void *info) > > { > @@ -241,8 +240,9 @@ static DEVICE_ATTR(fastsleep_workaround_applyonce, 0600, > * The default stop state that will be used by ppc_md.power_save > * function on platforms that support stop instruction. > */ > -u64 pnv_default_stop_val; > -u64 pnv_default_stop_mask; > +static u64 pnv_default_stop_val; > +static u64 pnv_default_stop_mask; > +static bool default_stop_found; > > /* > * Used for ppc_md.power_save which needs a function with no parameters > @@ -262,8 +262,9 @@ static void power9_idle(void) > * psscr value and mask of the deepest stop idle state. > * Used when a cpu is offlined. > */ > -u64 pnv_deepest_stop_psscr_val; > -u64 pnv_deepest_stop_psscr_mask; > +static u64 pnv_deepest_stop_psscr_val; > +static u64 pnv_deepest_stop_psscr_mask; > +static bool deepest_stop_found; Aha you have made them static. Nitpick withdrawn :) The log messages look good now. Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Hi, On Tue, Mar 21, 2017 at 02:39:34AM +1000, Nicholas Piggin wrote: > > @@ -241,8 +240,9 @@ static DEVICE_ATTR(fastsleep_workaround_applyonce, 0600, > > * The default stop state that will be used by ppc_md.power_save > > * function on platforms that support stop instruction. > > */ > > -u64 pnv_default_stop_val; > > -u64 pnv_default_stop_mask; > > +static u64 pnv_default_stop_val; > > +static u64 pnv_default_stop_mask; > > +static bool default_stop_found; > > > > /* > > * Used for ppc_md.power_save which needs a function with no parameters > > @@ -262,8 +262,9 @@ static void power9_idle(void) > > * psscr value and mask of the deepest stop idle state. > > * Used when a cpu is offlined. > > */ > > -u64 pnv_deepest_stop_psscr_val; > > -u64 pnv_deepest_stop_psscr_mask; > > +static u64 pnv_deepest_stop_psscr_val; > > +static u64 pnv_deepest_stop_psscr_mask; > > +static bool deepest_stop_found; > > Aha you have made them static. Nitpick withdrawn :) > > The log messages look good now. > > Reviewed-by: Nicholas Piggin <npiggin@gmail.com> > Thanks! -- Thanks and Regards gautham.
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c index f335e0f..63ade78 100644 --- a/arch/powerpc/platforms/powernv/idle.c +++ b/arch/powerpc/platforms/powernv/idle.c @@ -147,7 +147,6 @@ u32 pnv_get_supported_cpuidle_states(void) } EXPORT_SYMBOL_GPL(pnv_get_supported_cpuidle_states); - static void pnv_fastsleep_workaround_apply(void *info) { @@ -241,8 +240,9 @@ static DEVICE_ATTR(fastsleep_workaround_applyonce, 0600, * The default stop state that will be used by ppc_md.power_save * function on platforms that support stop instruction. */ -u64 pnv_default_stop_val; -u64 pnv_default_stop_mask; +static u64 pnv_default_stop_val; +static u64 pnv_default_stop_mask; +static bool default_stop_found; /* * Used for ppc_md.power_save which needs a function with no parameters @@ -262,8 +262,9 @@ static void power9_idle(void) * psscr value and mask of the deepest stop idle state. * Used when a cpu is offlined. */ -u64 pnv_deepest_stop_psscr_val; -u64 pnv_deepest_stop_psscr_mask; +static u64 pnv_deepest_stop_psscr_val; +static u64 pnv_deepest_stop_psscr_mask; +static bool deepest_stop_found; /* * pnv_cpu_offline: A function that puts the CPU into the deepest @@ -275,7 +276,7 @@ unsigned long pnv_cpu_offline(unsigned int cpu) u32 idle_states = pnv_get_supported_cpuidle_states(); - if (cpu_has_feature(CPU_FTR_ARCH_300)) { + if (cpu_has_feature(CPU_FTR_ARCH_300) && deepest_stop_found) { srr1 = power9_idle_stop(pnv_deepest_stop_psscr_val, pnv_deepest_stop_psscr_mask); } else if (idle_states & OPAL_PM_WINKLE_ENABLED) { @@ -385,7 +386,6 @@ static int __init pnv_power9_idle_init(struct device_node *np, u32 *flags, u32 *residency_ns = NULL; u64 max_residency_ns = 0; int rc = 0, i; - bool default_stop_found = false, deepest_stop_found = false; psscr_val = kcalloc(dt_idle_states, sizeof(*psscr_val), GFP_KERNEL); psscr_mask = kcalloc(dt_idle_states, sizeof(*psscr_mask), GFP_KERNEL); @@ -465,21 +465,24 @@ static int __init pnv_power9_idle_init(struct device_node *np, u32 *flags, } } - if (!default_stop_found) { - pnv_default_stop_val = PSSCR_HV_DEFAULT_VAL; - pnv_default_stop_mask = PSSCR_HV_DEFAULT_MASK; - pr_warn("Setting default stop psscr val=0x%016llx,mask=0x%016llx\n", + if (unlikely(!default_stop_found)) { + pr_warn("cpuidle-powernv: No suitable default stop state found. Disabling platform idle.\n"); + } else { + ppc_md.power_save = power9_idle; + pr_info("cpuidle-powernv: Default stop: psscr = 0x%016llx,mask=0x%016llx\n", pnv_default_stop_val, pnv_default_stop_mask); } - if (!deepest_stop_found) { - pnv_deepest_stop_psscr_val = PSSCR_HV_DEFAULT_VAL; - pnv_deepest_stop_psscr_mask = PSSCR_HV_DEFAULT_MASK; - pr_warn("Setting default stop psscr val=0x%016llx,mask=0x%016llx\n", + if (unlikely(!deepest_stop_found)) { + pr_warn("cpuidle-powernv: No suitable stop state for CPU-Hotplug. Offlined CPUs will busy wait"); + } else { + pr_info("cpuidle-powernv: Deepest stop: psscr = 0x%016llx,mask=0x%016llx\n", pnv_deepest_stop_psscr_val, pnv_deepest_stop_psscr_mask); } + pr_info("cpuidle-powernv: Requested Level (RL) value of first deep stop = 0x%llx\n", + pnv_first_deep_stop_state); out: kfree(psscr_val); kfree(psscr_mask); @@ -559,8 +562,6 @@ static int __init pnv_init_idle_states(void) if (supported_cpuidle_states & OPAL_PM_NAP_ENABLED) ppc_md.power_save = power7_idle; - else if (supported_cpuidle_states & OPAL_PM_STOP_INST_FAST) - ppc_md.power_save = power9_idle; out: return 0;