[PATCH 1/2] powerpc/cpuhotplug: Force ESL=1 for offline cpus

[Vaidyanathan Srinivasan]

From: Gautham R. Shenoy <ego at linux.vnet.ibm.com>

ESL=1 losses some HYP SPR context and not idea for cpuidle,
however can be used for offline cpus.

Signed-off-by: Vaidyanathan Srinivasan <svaidy at linux.vnet.ibm.com>
Signed-off-by: Gautham R. Shenoy <ego at linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/cpuidle.h    | 15 +++++++++++++++
 arch/powerpc/platforms/powernv/idle.c | 11 +++++++++++
 2 files changed, 26 insertions(+)

diff --git a/arch/powerpc/include/asm/cpuidle.h b/arch/powerpc/include/asm/cpuidle.h
index fd321eb4..31192d8 100644
--- a/arch/powerpc/include/asm/cpuidle.h
+++ b/arch/powerpc/include/asm/cpuidle.h
@@ -40,6 +40,21 @@
 #define ERR_EC_ESL_MISMATCH		-1
 #define ERR_DEEP_STATE_ESL_MISMATCH	-2
 
+/* Additional defs for debug and trace */
+
+#define RL_SHIFT      0
+#define MTL_SHIFT     4
+#define TR_SHIFT      8
+#define PSLL_SHIFT    16
+#define EC_SHIFT      20
+#define ESL_SHIFT     21
+#define INIT_PSSCR(ESL, EC, PSLL, TR, MTL, RL)	(((ESL) << (ESL_SHIFT)) | \
+						 ((EC) << (EC_SHIFT)) | \
+						 ((PSLL) << (PSLL_SHIFT)) | \
+						 ((TR) << (TR_SHIFT)) | \
+						 ((MTL) << (MTL_SHIFT)) | \
+						 ((RL) << (RL_SHIFT)))
+
 #ifndef __ASSEMBLY__
 extern u32 pnv_fastsleep_workaround_at_entry[];
 extern u32 pnv_fastsleep_workaround_at_exit[];
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
index 4ee837e..4f0663a 100644
--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -524,6 +524,17 @@ static int __init pnv_init_idle_states(void)
 
 	pnv_alloc_idle_core_states();
 
+	/* On POWER9 DD1, enter stop2 with ESL=EC=1 on Hotplug */
+	if (cpu_has_feature(CPU_FTR_POWER9_DD1)) {
+		pnv_deepest_stop_psscr_val =
+				/* ESL, EC, PSSL, TR,  MTL, RL */
+			INIT_PSSCR(0x1, 0x1, 0xf, 0x3, 0x3, 0x2);
+		pnv_deepest_stop_psscr_mask = PSSCR_HV_DEFAULT_MASK;
+		pr_warn("Overriding deepest_stop_psscr to: val=0x%016llx,mask=0x%016llx\n",
+			pnv_deepest_stop_psscr_val,
+			pnv_deepest_stop_psscr_mask);
+	}
+
 	if (supported_cpuidle_states & OPAL_PM_NAP_ENABLED)
 		ppc_md.power_save = power7_idle;
 	else if (supported_cpuidle_states & OPAL_PM_STOP_INST_FAST)
-- 
2.9.3