| Message ID | 20200427021027.114582-3-huntbag@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [RFC,1/3] powernv/cpuidle : Support for pre-entry and post exit of stop state in firmware | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch powerpc/merge (54dc28ff5e0b3585224d49a31b53e030342ca5c3) |
| snowpatch_ozlabs/build-ppc64le | warning | Build succeeded but added 11 new sparse warnings |
| snowpatch_ozlabs/build-ppc64be | warning | Build succeeded but added 2 new sparse warnings |
| snowpatch_ozlabs/build-ppc64e | success | Build succeeded |
| snowpatch_ozlabs/build-pmac32 | warning | Upstream build failed, couldn't test patch |
| snowpatch_ozlabs/checkpatch | warning | total: 0 errors, 0 warnings, 2 checks, 74 lines checked |
| snowpatch_ozlabs/needsstable | success | Patch has no Fixes tags |
On Sun, Apr 26, 2020 at 09:10:27PM -0500, Abhishek Goel wrote: > This patch introduces the capability for firmware to handle the stop > states instead. A bit is set based on the discovery of the feature > and correspondingly also the responsibility to handle the stop states. > > If Kernel does not know about stop version, it can fallback to opal for > idle stop support if firmware-stop-supported property is present. > > Earlier this patch was posted as part of this series : > https://lkml.org/lkml/2020/3/4/589 > > Signed-off-by: Pratik Rajesh Sampat <psampat@linux.ibm.com> > Signed-off-by: Abhishek Goel <huntbag@linux.vnet.ibm.com> > --- > > v1->v2: This patch is newly added in this series. > > arch/powerpc/include/asm/processor.h | 1 + > arch/powerpc/kernel/dt_cpu_ftrs.c | 8 ++++++++ > arch/powerpc/platforms/powernv/idle.c | 27 ++++++++++++++++----------- > 3 files changed, 25 insertions(+), 11 deletions(-) > > diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h > index 66fa20476d0e..d5c6532b11ef 100644 > --- a/arch/powerpc/include/asm/processor.h > +++ b/arch/powerpc/include/asm/processor.h > @@ -430,6 +430,7 @@ extern unsigned long cpuidle_disable; > enum idle_boot_override {IDLE_NO_OVERRIDE = 0, IDLE_POWERSAVE_OFF}; > > #define STOP_ENABLE 0x00000001 > +#define FIRMWARE_STOP_ENABLE 0x00000010 > > #define STOP_VERSION_P9 0x1 > > diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c b/arch/powerpc/kernel/dt_cpu_ftrs.c > index db1a525e090d..ff4a87b79702 100644 > --- a/arch/powerpc/kernel/dt_cpu_ftrs.c > +++ b/arch/powerpc/kernel/dt_cpu_ftrs.c > @@ -298,6 +298,13 @@ static int __init feat_enable_idle_stop(struct dt_cpu_feature *f) > return 1; > } > > +static int __init feat_enable_firmware_stop(struct dt_cpu_feature *f) > +{ > + stop_dep.cpuidle_prop |= FIRMWARE_STOP_ENABLE; > + > + return 1; > +} > + > static int __init feat_enable_mmu_hash(struct dt_cpu_feature *f) > { > u64 lpcr; > @@ -592,6 +599,7 @@ static struct dt_cpu_feature_match __initdata > {"idle-nap", feat_enable_idle_nap, 0}, > {"alignment-interrupt-dsisr", feat_enable_align_dsisr, 0}, > {"idle-stop", feat_enable_idle_stop, 0}, > + {"firmware-stop-supported", feat_enable_firmware_stop, 0}, > {"machine-check-power8", feat_enable_mce_power8, 0}, > {"performance-monitor-power8", feat_enable_pmu_power8, 0}, > {"data-stream-control-register", feat_enable_dscr, CPU_FTR_DSCR}, > diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c > index 538f0842ac3f..0de5de81902e 100644 > --- a/arch/powerpc/platforms/powernv/idle.c > +++ b/arch/powerpc/platforms/powernv/idle.c > @@ -633,16 +633,6 @@ static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on) > unsigned long mmcr0 = 0; > struct p9_sprs sprs = {}; /* avoid false used-uninitialised */ > bool sprs_saved = false; > - int rc = 0; > - > - /* > - * Kernel takes decision whether to make OPAL call or not. This logic > - * will be combined with the logic for BE opal to take decision. > - */ > - if (firmware_stop_supported) { > - rc = opal_cpu_idle(cpu_to_be64(__pa(&srr1)), (uint64_t) psscr); > - goto out; > - } > > if (!(psscr & (PSSCR_EC|PSSCR_ESL))) { > /* EC=ESL=0 case */ > @@ -835,6 +825,19 @@ static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on) > return srr1; > } > > +static unsigned long power9_firmware_idle_stop(unsigned long psscr, bool mmu_on) > +{ > + unsigned long srr1; > + int rc; > + > + rc = opal_cpu_idle(cpu_to_be64(__pa(&srr1)), (uint64_t) psscr); > + > + if (mmu_on) > + mtmsr(MSR_KERNEL); > + return srr1; > + > +} > + > #ifdef CONFIG_HOTPLUG_CPU > static unsigned long power9_offline_stop(unsigned long psscr) > { > @@ -1394,9 +1397,11 @@ static int __init pnv_init_idle_states(void) > !(stop_dep.cpuidle_prop & STOP_ENABLE)) > goto out; > > - /* Check for supported version in kernel */ > + /* Check for supported version in kernel or fallback to kernel*/ > if (stop_dep.stop_version & STOP_VERSION_P9) { > stop_dep.idle_stop = power9_idle_stop; > + } else if (stop_dep.cpuidle_prop & FIRMWARE_STOP_ENABLE) { > + stop_dep.idle_stop = power9_firmware_idle_stop; Ok, so in this patch you first check if the "idle-stop" feature is available. Only otherwise you fallback to the OPAL based cpuidle driver. This looks ok to me. > } else { > stop_dep.idle_stop = NULL; > goto out; > -- > 2.17.1 > -- Thanks and Regards gautham.
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h index 66fa20476d0e..d5c6532b11ef 100644 --- a/arch/powerpc/include/asm/processor.h +++ b/arch/powerpc/include/asm/processor.h @@ -430,6 +430,7 @@ extern unsigned long cpuidle_disable; enum idle_boot_override {IDLE_NO_OVERRIDE = 0, IDLE_POWERSAVE_OFF}; #define STOP_ENABLE 0x00000001 +#define FIRMWARE_STOP_ENABLE 0x00000010 #define STOP_VERSION_P9 0x1 diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c b/arch/powerpc/kernel/dt_cpu_ftrs.c index db1a525e090d..ff4a87b79702 100644 --- a/arch/powerpc/kernel/dt_cpu_ftrs.c +++ b/arch/powerpc/kernel/dt_cpu_ftrs.c @@ -298,6 +298,13 @@ static int __init feat_enable_idle_stop(struct dt_cpu_feature *f) return 1; } +static int __init feat_enable_firmware_stop(struct dt_cpu_feature *f) +{ + stop_dep.cpuidle_prop |= FIRMWARE_STOP_ENABLE; + + return 1; +} + static int __init feat_enable_mmu_hash(struct dt_cpu_feature *f) { u64 lpcr; @@ -592,6 +599,7 @@ static struct dt_cpu_feature_match __initdata {"idle-nap", feat_enable_idle_nap, 0}, {"alignment-interrupt-dsisr", feat_enable_align_dsisr, 0}, {"idle-stop", feat_enable_idle_stop, 0}, + {"firmware-stop-supported", feat_enable_firmware_stop, 0}, {"machine-check-power8", feat_enable_mce_power8, 0}, {"performance-monitor-power8", feat_enable_pmu_power8, 0}, {"data-stream-control-register", feat_enable_dscr, CPU_FTR_DSCR}, diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c index 538f0842ac3f..0de5de81902e 100644 --- a/arch/powerpc/platforms/powernv/idle.c +++ b/arch/powerpc/platforms/powernv/idle.c @@ -633,16 +633,6 @@ static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on) unsigned long mmcr0 = 0; struct p9_sprs sprs = {}; /* avoid false used-uninitialised */ bool sprs_saved = false; - int rc = 0; - - /* - * Kernel takes decision whether to make OPAL call or not. This logic - * will be combined with the logic for BE opal to take decision. - */ - if (firmware_stop_supported) { - rc = opal_cpu_idle(cpu_to_be64(__pa(&srr1)), (uint64_t) psscr); - goto out; - } if (!(psscr & (PSSCR_EC|PSSCR_ESL))) { /* EC=ESL=0 case */ @@ -835,6 +825,19 @@ static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on) return srr1; } +static unsigned long power9_firmware_idle_stop(unsigned long psscr, bool mmu_on) +{ + unsigned long srr1; + int rc; + + rc = opal_cpu_idle(cpu_to_be64(__pa(&srr1)), (uint64_t) psscr); + + if (mmu_on) + mtmsr(MSR_KERNEL); + return srr1; + +} + #ifdef CONFIG_HOTPLUG_CPU static unsigned long power9_offline_stop(unsigned long psscr) { @@ -1394,9 +1397,11 @@ static int __init pnv_init_idle_states(void) !(stop_dep.cpuidle_prop & STOP_ENABLE)) goto out; - /* Check for supported version in kernel */ + /* Check for supported version in kernel or fallback to kernel*/ if (stop_dep.stop_version & STOP_VERSION_P9) { stop_dep.idle_stop = power9_idle_stop; + } else if (stop_dep.cpuidle_prop & FIRMWARE_STOP_ENABLE) { + stop_dep.idle_stop = power9_firmware_idle_stop; } else { stop_dep.idle_stop = NULL; goto out;