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From: Michael Neuling <mikey@neuling.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Alexander Graf <agraf@suse.de>
Cc: Michael Neuling <mikey@neuling.org>,
	kvm@vger.kernel.org, kvm-ppc@vger.kernel.org,
	Paul Mackerras <paulus@samba.org>,
	linuxppc-dev@lists.ozlabs.org
Subject: [PATCH 2/6] powerpc/powernv: Make it possible to skip the IRQHAPPENED check in power7_nap()
Date: Thu, 24 Apr 2014 11:32:41 +1000	[thread overview]
Message-ID: <1398303165-6576-3-git-send-email-mikey@neuling.org> (raw)
In-Reply-To: <1398303165-6576-1-git-send-email-mikey@neuling.org>

From: Michael Ellerman <mpe@ellerman.id.au>

To support split core we need to be able to force all secondaries into
nap, so the core can detect they are idle and do an unsplit.

Currently power7_nap() will return without napping if there is an irq
pending. We want to ignore the pending irq and nap anyway, we will deal
with the interrupt later.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Neuling <mikey@neuling.org>
---
 arch/powerpc/include/asm/processor.h | 2 +-
 arch/powerpc/kernel/idle_power7.S    | 9 +++++++++
 arch/powerpc/platforms/powernv/smp.c | 2 +-
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index d660dc3..6d59072 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -449,7 +449,7 @@ extern unsigned long cpuidle_disable;
 enum idle_boot_override {IDLE_NO_OVERRIDE = 0, IDLE_POWERSAVE_OFF};
 
 extern int powersave_nap;	/* set if nap mode can be used in idle loop */
-extern void power7_nap(void);
+extern void power7_nap(int check_irq);
 extern void power7_sleep(void);
 extern void flush_instruction_cache(void);
 extern void hard_reset_now(void);
diff --git a/arch/powerpc/kernel/idle_power7.S b/arch/powerpc/kernel/idle_power7.S
index c3ab869..063c7cb 100644
--- a/arch/powerpc/kernel/idle_power7.S
+++ b/arch/powerpc/kernel/idle_power7.S
@@ -39,6 +39,10 @@
  * Pass requested state in r3:
  * 	0 - nap
  * 	1 - sleep
+ *
+ * To check IRQ_HAPPENED in r4
+ * 	0 - don't check
+ * 	1 - check
  */
 _GLOBAL(power7_powersave_common)
 	/* Use r3 to pass state nap/sleep/winkle */
@@ -71,6 +75,8 @@ _GLOBAL(power7_powersave_common)
 	lbz	r0,PACAIRQHAPPENED(r13)
 	cmpwi	cr0,r0,0
 	beq	1f
+	cmpwi	cr0,r4,0
+	beq	1f
 	addi	r1,r1,INT_FRAME_SIZE
 	ld	r0,16(r1)
 	mtlr	r0
@@ -115,14 +121,17 @@ _GLOBAL(power7_idle)
 	cmpwi	0,r4,0
 	beqlr
 	/* fall through */
+	li	r3, 1
 
 _GLOBAL(power7_nap)
+	mr	r4,r3
 	li	r3,0
 	b	power7_powersave_common
 	/* No return */
 
 _GLOBAL(power7_sleep)
 	li	r3,1
+	li	r4,0
 	b	power7_powersave_common
 	/* No return */
 
diff --git a/arch/powerpc/platforms/powernv/smp.c b/arch/powerpc/platforms/powernv/smp.c
index 908672b..ab8b4ad 100644
--- a/arch/powerpc/platforms/powernv/smp.c
+++ b/arch/powerpc/platforms/powernv/smp.c
@@ -156,7 +156,7 @@ static void pnv_smp_cpu_kill_self(void)
 	 */
 	mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~(u64)LPCR_PECE1);
 	while (!generic_check_cpu_restart(cpu)) {
-		power7_nap();
+		power7_nap(1);
 		if (!generic_check_cpu_restart(cpu)) {
 			DBG("CPU%d Unexpected exit while offline !\n", cpu);
 			/* We may be getting an IPI, so we re-enable
-- 
1.8.3.2

  parent reply	other threads:[~2014-04-24  1:32 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-04-24  1:32 [PATCH 0/6] Implement split core for POWER8 Michael Neuling
2014-04-24  1:32 ` [PATCH 1/6] KVM: PPC: Book3S HV: Rework the secondary inhibit code Michael Neuling
2014-04-24  1:32 ` Michael Neuling [this message]
2014-04-24  1:32 ` [PATCH 3/6] powerpc: Add threads_per_subcore Michael Neuling
2014-04-24  1:32 ` [PATCH 4/6] powerpc: Check cpu_thread_in_subcore() in __cpu_up() Michael Neuling
2014-04-24  1:32 ` [PATCH 5/6] KVM: PPC: Book3S HV: Use threads_per_subcore in KVM Michael Neuling
2014-04-24  1:32 ` [PATCH 6/6] powerpc/powernv: Add support for POWER8 split core on powernv Michael Neuling
2014-04-24  4:02   ` Joel Stanley
2014-04-24  4:06     ` Michael Neuling
2014-04-30  5:09 ` [PATCH 0/6] Implement split core for POWER8 Michael Neuling
2014-04-30  9:52   ` Alexander Graf

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