powerpc/powernv: Make it possible to skip the IRQHAPPENED check in power7_nap()

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>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

3 files changed, 11 insertions, 2 deletions

diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index d660dc36831a..6d59072e13a7 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 dca6e16c2436..2480256272d4 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
@@ -114,15 +120,18 @@ _GLOBAL(power7_idle)
         lwz     r4,ADDROFF(powersave_nap)(r3)
         cmpwi   0,r4,0
         beqlr
+        li      r3, 1
         /* fall through */
 
 _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 1601a1ea02c4..65faf998fe2c 100644
--- a/arch/powerpc/platforms/powernv/smp.c
+++ b/arch/powerpc/platforms/powernv/smp.c
@@ -159,7 +159,7 @@ static void pnv_smp_cpu_kill_self(void)
         mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~(u64)LPCR_PECE1);
         while (!generic_check_cpu_restart(cpu)) {
                 ppc64_runlatch_off();
-                power7_nap();
+                power7_nap(1);
                 ppc64_runlatch_on();
                 if (!generic_check_cpu_restart(cpu)) {
                         DBG("CPU%d Unexpected exit while offline !\n", cpu);