FAILED: patch "[PATCH] powerpc/64s: Fix system reset interrupt winkle wakeups" failed to apply to 4.8-stable tree
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[email protected]
maintainerThe patch below does not apply to the 4.8-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
Quoted 1 line
From
f23ed166f283b1a6f0a1f0b0c889e8df9a10ff85Mon Sep 17 00:00:00 2001
From: Nicholas Piggin <[email protected]>
Date: Wed, 2 Nov 2016 17:57:01 +1100
Subject: [PATCH] powerpc/64s: Fix system reset interrupt winkle wakeups
Wakeups from winkle set the low bit of the HSPRG0 register, to distinguish it from other sleep states. This is also the PACA pointer. The system reset exception handler fails to mask this bit away before using this value before using it as the PACA pointer.
Fix this by adding a new type of exception prolog macro where we already have the PACA set in r13, and have the system reset vector mask it out. The winkle wakeup handler will store the masked value back into HSPRG0.
arch/powerpc/include/asm/exception-64s.h +11 -2
@@ -158,14 +158,17 @@ BEGIN_FTR_SECTION_NESTED(943) \std ra,offset (r13 ); \ END_FTR_SECTION_NESTED(ftr,ftr,943) -#define EXCEPTION_PROLOG_0 (area) \ - GET_PACA(r13); \ +#define EXCEPTION_PROLOG_0_PACA (area) \ std r9,area+EX_R9(r13);/* save r9 */ \OPT_GET_SPR (r9,SPRN_PPR ,CPU_FTR_HAS_PPR ); \HMT_MEDIUM ; \ std r10,area+EX_R10(r13); /* save r10 - r12 */ \ OPT_GET_SPR(r10, SPRN_CFAR, CPU_FTR_CFAR) +#define EXCEPTION_PROLOG_0 (area) \ + GET_PACA(r13); \ + EXCEPTION_PROLOG_0_PACA(area) +#define __EXCEPTION_PROLOG_1 (area, extra, vec) \ OPT_SAVE_REG_TO_PACA(area+EX_PPR, r9, CPU_FTR_HAS_PPR); \ OPT_SAVE_REG_TO_PACA(area+EX_CFAR, r10, CPU_FTR_CFAR); \
@@ -196,6 +199,12 @@ END_FTR_SECTION_NESTED(ftr,ftr,943)EXCEPTION_PROLOG_1 (area, extra, vec); \EXCEPTION_PROLOG_PSERIES_1 (label, h); +/* Have the PACA in r13 already */ +#define EXCEPTION_PROLOG_PSERIES_PACA (area, label, h, extra, vec) \ + EXCEPTION_PROLOG_0_PACA(area); \ + EXCEPTION_PROLOG_1(area, extra, vec); \ + EXCEPTION_PROLOG_PSERIES_1(label, h); +#define __KVMTEST (h, n) \ lbz r10,HSTATE_IN_GUEST(r13); \ cmpwi r10,0; \
arch/powerpc/kernel/exceptions-64s.S +8 -3
@@ -116,7 +116,9 @@ EXC_VIRT_NONE(0x4000, 0x4100) EXC_REAL_BEGIN(system_reset, 0x100, 0x200) SET_SCRATCH0(r13) - EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common, EXC_STD, + GET_PACA(r13) + clrrdi r13,r13,1 /* Last bit of HSPRG0 is set if waking from winkle */ + EXCEPTION_PROLOG_PSERIES_PACA(PACA_EXGEN, system_reset_common, EXC_STD, IDLETEST, 0x100) EXC_REAL_END(system_reset, 0x100, 0x200)
@@ -124,6 +126,9 @@ EXC_VIRT_NONE(0x4100, 0x4200) #ifdef CONFIG_PPC_P7_NAP EXC_COMMON_BEGIN(system_reset_idle_common) +BEGIN_FTR_SECTION + GET_PACA(r13) /* Restore HSPRG0 to get the winkle bit in r13 */ +END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300) bl pnv_restore_hyp_resource li r0,PNV_THREAD_RUNNING
@@ -169,7 +174,7 @@ EXC_REAL_BEGIN(machine_check, 0x200, 0x300) SET_SCRATCH0(r13) /* save r13 */ /* * Running native on arch 2.06 or later, we may wakeup from winkle - * inside machine check. If yes, then last bit of HSPGR0 would be set + * inside machine check. If yes, then last bit of HSPRG0 would be set * to 1. Hence clear it unconditionally. */ GET_PACA(r13)
@@ -388,7 +393,7 @@ EXC_COMMON_BEGIN(machine_check_handle_early) /* * Go back to winkle. Please note that this thread was woken up in * machine check from winkle and have not restored the per-subcore - * state. Hence before going back to winkle, set last bit of HSPGR0 + * state. Hence before going back to winkle, set last bit of HSPRG0 * to 1. This will make sure that if this thread gets woken up * again at reset vector 0x100 then it will get chance to restore * the subcore state.