Concept patch demonstrating an idle-stop version discovery from the
device tree, along with population its support and versioning. It also
assigns the function pointer to handle any idle-stop specific quirks.
Signed-off-by: Pratik Rajesh Sampat <psam...@linux.ibm.com>
---
arch/powerpc/include/asm/processor.h | 1 +
arch/powerpc/kernel/dt_cpu_ftrs.c | 16 ++++++++++++++++
arch/powerpc/platforms/powernv/idle.c | 8 ++++++++
3 files changed, 25 insertions(+)
diff --git a/arch/powerpc/include/asm/processor.h
b/arch/powerpc/include/asm/processor.h
index da59f01a5c09..277dbabafd02 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -432,6 +432,7 @@ enum idle_boot_override {IDLE_NO_OVERRIDE = 0,
IDLE_POWERSAVE_OFF};
#define STOP_ENABLE 0x00000001
#define STOP_VERSION_P9 0x1
+#define STOP_VERSION_P9_V1 0x2
/*
* Classify the dependencies of the stop states
diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c
b/arch/powerpc/kernel/dt_cpu_ftrs.c
index db1a525e090d..63e30aa49356 100644
--- a/arch/powerpc/kernel/dt_cpu_ftrs.c
+++ b/arch/powerpc/kernel/dt_cpu_ftrs.c
@@ -298,6 +298,21 @@ static int __init feat_enable_idle_stop(struct
dt_cpu_feature *f)
return 1;
}
+static int __init feat_enable_idle_stop_quirk(struct dt_cpu_feature *f)
+{
+ u64 lpcr;
+
+ /* Set PECE wakeup modes for ISAv3.0B */
+ lpcr = mfspr(SPRN_LPCR);
+ lpcr |= LPCR_PECE0;
+ lpcr |= LPCR_PECE1;
+ lpcr |= LPCR_PECE2;
+ mtspr(SPRN_LPCR, lpcr);
+ stop_dep.cpuidle_prop |= STOP_ENABLE;
+ stop_dep.stop_version = STOP_VERSION_P9_V1;
+
+ return 1;
+}
static int __init feat_enable_mmu_hash(struct dt_cpu_feature *f)
{
u64 lpcr;
@@ -592,6 +607,7 @@ 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},
+ {"idle-stop-v1", feat_enable_idle_stop_quirk, 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 c32cdc37acf4..9f5b21da2fc5 100644
--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -805,6 +805,11 @@ static unsigned long power9_idle_stop(unsigned long psscr,
bool mmu_on)
return srr1;
}
+static unsigned long power9_idle_quirky_stop(unsigned long psscr, bool mmu_on)
+{
+ return power9_idle_stop(psscr, mmu_on);
+}
+
#ifdef CONFIG_HOTPLUG_CPU
static unsigned long power9_offline_stop(unsigned long psscr)
{
@@ -1360,6 +1365,9 @@ static int __init pnv_init_idle_states(void)
case STOP_VERSION_P9:
stop_dep.idle_stop = power9_idle_stop;
break;
+ case STOP_VERSION_P9_V1:
+ stop_dep.idle_stop = power9_idle_quirky_stop;
+ break;
default:
stop_dep.idle_stop = NULL;
goto out;
--
2.24.1
