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Groups > linux.kernel > #1526972 > unrolled thread
| Started by | "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> |
|---|---|
| First post | 2016-11-21 19:40 +0100 |
| Last post | 2016-11-22 22:20 +0100 |
| Articles | 3 — 2 participants |
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[RFC/PATCH] powernv: Handle wakeup from stop due to SRESET "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> - 2016-11-21 19:40 +0100
[PATCH v2] powernv: Handle wakeup from idle due to SRESET "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> - 2016-11-22 18:40 +0100
Re: [PATCH v2] powernv: Handle wakeup from idle due to SRESET Paul Mackerras <paulus@ozlabs.org> - 2016-11-22 22:20 +0100
| From | "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> |
|---|---|
| Date | 2016-11-21 19:40 +0100 |
| Subject | [RFC/PATCH] powernv: Handle wakeup from stop due to SRESET |
| Message-ID | <sG1Fw-4P0-7@gated-at.bofh.it> |
From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> 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 <ego@linux.vnet.ibm.com> --- 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) -- 1.8.3.1
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| From | "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> |
|---|---|
| Date | 2016-11-22 18:40 +0100 |
| Subject | [PATCH v2] powernv: Handle wakeup from idle due to SRESET |
| Message-ID | <sGnd0-1Py-49@gated-at.bofh.it> |
| In reply to | #1526972 |
From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> 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 <ego@linux.vnet.ibm.com> --- v1 -> v2: Set r9,r11,r12 to CR,SRR0,SRR1 values before jumping to system_reset_common as expected by EXCEPTION_PROLOG_COMMON arch/powerpc/kernel/idle_book3s.S | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S index 72dac0b..06afe0e 100644 --- a/arch/powerpc/kernel/idle_book3s.S +++ b/arch/powerpc/kernel/idle_book3s.S @@ -353,6 +353,22 @@ 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; \ + ld r1,PACAR1(r13); \ + ld r9,_CCR(r1); \ + ld r11,_NIP(r1); \ + mfspr r12, SPRN_SRR1; \ + 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 +660,7 @@ _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 +683,7 @@ _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) -- 1.8.3.1
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| From | Paul Mackerras <paulus@ozlabs.org> |
|---|---|
| Date | 2016-11-22 22:20 +0100 |
| Subject | Re: [PATCH v2] powernv: Handle wakeup from idle due to SRESET |
| Message-ID | <sGqDT-493-3@gated-at.bofh.it> |
| In reply to | #1527762 |
On Tue, Nov 22, 2016 at 11:06:32PM +0530, Gautham R. Shenoy wrote: > From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> > > 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 <ego@linux.vnet.ibm.com> > --- > v1 -> v2: Set r9,r11,r12 to CR,SRR0,SRR1 values > before jumping to system_reset_common as expected by > EXCEPTION_PROLOG_COMMON > > arch/powerpc/kernel/idle_book3s.S | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S > index 72dac0b..06afe0e 100644 > --- a/arch/powerpc/kernel/idle_book3s.S > +++ b/arch/powerpc/kernel/idle_book3s.S > @@ -353,6 +353,22 @@ 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; \ > + ld r1,PACAR1(r13); \ > + ld r9,_CCR(r1); \ > + ld r11,_NIP(r1); \ > + mfspr r12, SPRN_SRR1; \ > + 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); \ What's the point of the else section? Paul.
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