[RFC/PATCH] powernv: Handle wakeup from stop due to SRESET
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From: Gautham R. Shenoy <hidden>
Date: 2016-11-21 18:38:52
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
From: "Gautham R. Shenoy" <redacted> The existing code doesn't handle the case when CPU which was in a hardware-idle state (nap,sleep,winkle on POWER8 and various stop states on POWER9) gets woken up due to a System Reset interrupt. This patch checks if the CPU was woken up due to System Reset, in which case, after restoring the required hardware state, it jumps to the system reset handler. Signed-off-by: Gautham R. Shenoy <redacted> --- arch/powerpc/kernel/idle_book3s.S | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S
index 72dac0b..0098879 100644
--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S@@ -353,6 +353,18 @@ ALT_FTR_SECTION_END_NESTED_IFSET(CPU_FTR_ARCH_207S, 66); \ ld r3,ORIG_GPR3(r1); /* Restore original r3 */ \ 20: nop; +#define CHECK_SRESET_INTERRUPT \ +BEGIN_FTR_SECTION_NESTED(67); \ + mfspr r0,SPRN_SRR1; \ + rlwinm r0,r0,45-31,0xf; /* Extract wake reason field (P8,9) */ \ + cmpwi r0,0x4; /* System Reset ? */ \ + bne 21f; \ + b system_reset_common; \ + b .; /* We shouldn't return here */ \ +FTR_SECTION_ELSE_NESTED(67); \ + nop ; \ +ALT_FTR_SECTION_END_NESTED_IFSET(CPU_FTR_ARCH_207S, 67); \ +21: nop; /* * r3 - requested stop state
@@ -644,6 +656,7 @@ _GLOBAL(pnv_wakeup_loss) ld r1,PACAR1(r13) BEGIN_FTR_SECTION CHECK_HMI_INTERRUPT + CHECK_SRESET_INTERRUPT END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) REST_NVGPRS(r1) REST_GPR(2, r1)
@@ -666,6 +679,7 @@ _GLOBAL(pnv_wakeup_noloss) bne pnv_wakeup_loss BEGIN_FTR_SECTION CHECK_HMI_INTERRUPT + CHECK_SRESET_INTERRUPT END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) ld r1,PACAR1(r13) ld r6,_CCR(r1)
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1.8.3.1