diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index 4b594ed6180a002ee30a2d7ab15d64ecb9cbc770..d4f653c9259a29745dbbcb5f451d7a48e55d9bcf 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -659,6 +659,7 @@ #define SRR1_ISI_PROT 0x08000000 /* ISI: Other protection fault */ #define SRR1_WAKEMASK 0x00380000 /* reason for wakeup */ #define SRR1_WAKEMASK_P8 0x003c0000 /* reason for wakeup on POWER8 and 9 */ +#define SRR1_WAKEMCE_RESVD 0x003c0000 /* Unused/reserved value used by MCE wakeup to indicate cause to idle wakeup handler */ #define SRR1_WAKESYSERR 0x00300000 /* System error */ #define SRR1_WAKEEE 0x00200000 /* External interrupt */ #define SRR1_WAKEHVI 0x00240000 /* Hypervisor Virtualization Interrupt (P9) */ diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index e390fcd04bcb86bcb48a16565f7937b23231c1a4..28f8d7bed6b12a089754a753e3704160f4f52332 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -178,6 +178,12 @@ BEGIN_FTR_SECTION * NOTE: We are here with MSR_ME=0 (off), which means we risk a * checkstop if we get another machine check exception before we do * rfid with MSR_ME=1. + * + * This interrupt can wake directly from idle. If that is the case, + * the machine check is handled then the idle wakeup code is called + * to restore state. In that case, the POWER9 DD1 idle PACA workaround + * is not applied in the early machine check code, which will cause + * bugs. */ mr r11,r1 /* Save r1 */ lhz r10,PACA_IN_MCE(r13) @@ -306,6 +312,37 @@ EXC_COMMON_BEGIN(machine_check_common) /* restore original r1. */ \ ld r1,GPR1(r1) +#ifdef CONFIG_PPC_P7_NAP +/* + * This is an idle wakeup. Low level machine check has already been + * done. Queue the event then call the idle code to do the wake up. + */ +EXC_COMMON_BEGIN(machine_check_idle_common) + bl machine_check_queue_event + + /* + * We have not used any non-volatile GPRs here, and as a rule + * most exception code including machine check does not. + * Therefore PACA_NAPSTATELOST does not need to be set. Idle + * wakeup will restore volatile registers. + * + * Load the original SRR1 into r3 for pnv_powersave_wakeup_mce. + * + * Then decrement MCE nesting after finishing with the stack. + */ + ld r3,_MSR(r1) + + lhz r11,PACA_IN_MCE(r13) + subi r11,r11,1 + sth r11,PACA_IN_MCE(r13) + + /* Turn off the RI bit because SRR1 is used by idle wakeup code. */ + /* Recoverability could be improved by reducing the use of SRR1. */ + li r11,0 + mtmsrd r11,1 + + b pnv_powersave_wakeup_mce +#endif /* * Handle machine check early in real mode. We come here with * ME=1, MMU (IR=0 and DR=0) off and using MC emergency stack. @@ -318,6 +355,7 @@ EXC_COMMON_BEGIN(machine_check_handle_early) bl machine_check_early std r3,RESULT(r1) /* Save result */ ld r12,_MSR(r1) + #ifdef CONFIG_PPC_P7_NAP /* * Check if thread was in power saving mode. We come here when any @@ -328,43 +366,14 @@ EXC_COMMON_BEGIN(machine_check_handle_early) * * Go back to nap/sleep/winkle mode again if (b) is true. */ - rlwinm. r11,r12,47-31,30,31 /* Was it in power saving mode? */ - beq 4f /* No, it wasn't */ - /* Thread was in power saving mode. Go back to nap again. */ - cmpwi r11,2 - blt 3f - /* Supervisor/Hypervisor state loss */ - li r0,1 - stb r0,PACA_NAPSTATELOST(r13) -3: bl machine_check_queue_event - MACHINE_CHECK_HANDLER_WINDUP - GET_PACA(r13) - ld r1,PACAR1(r13) - /* - * Check what idle state this CPU was in and go back to same mode - * again. - */ - lbz r3,PACA_THREAD_IDLE_STATE(r13) - cmpwi r3,PNV_THREAD_NAP - bgt 10f - IDLE_STATE_ENTER_SEQ_NORET(PPC_NAP) - /* No return */ -10: - cmpwi r3,PNV_THREAD_SLEEP - bgt 2f - IDLE_STATE_ENTER_SEQ_NORET(PPC_SLEEP) - /* No return */ - -2: - /* - * 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. - */ - IDLE_STATE_ENTER_SEQ_NORET(PPC_WINKLE) - /* No return */ + BEGIN_FTR_SECTION + rlwinm. r11,r12,47-31,30,31 + beq- 4f + BRANCH_TO_COMMON(r10, machine_check_idle_common) 4: + END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206) #endif + /* * Check if we are coming from hypervisor userspace. If yes then we * continue in host kernel in V mode to deliver the MC event. diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S index dd8ca7fdf55ab22ff5f5d6dd2aa19ab282904a61..4e5a4fed86c5aafde6d48ac8f0bf353ec5657427 100644 --- a/arch/powerpc/kernel/idle_book3s.S +++ b/arch/powerpc/kernel/idle_book3s.S @@ -415,6 +415,31 @@ power9_dd1_recover_paca: stb r0,PACA_NAPSTATELOST(r13) blr +/* + * Called from machine check handler for powersave wakeups. + * Low level machine check processing has already been done. Now just + * go through the wake up path to get everything in order. + * + * r3 - The original SRR1 value. + * Original SRR[01] have been clobbered. + * MSR_RI is clear. + */ +.global pnv_powersave_wakeup_mce +pnv_powersave_wakeup_mce: + /* Set cr3 for pnv_powersave_wakeup */ + rlwinm r11,r3,47-31,30,31 + cmpwi cr3,r11,2 + + /* + * Now put the original SRR1 with SRR1_WAKEMCE_RESVD as the wake + * reason into SRR1, which allows reuse of the system reset wakeup + * code without being mistaken for another type of wakeup. + */ + oris r3,r3,SRR1_WAKEMCE_RESVD@h + mtspr SPRN_SRR1,r3 + + b pnv_powersave_wakeup + /* * Called from reset vector for powersave wakeups. * cr3 - set to gt if waking up with partial/complete hypervisor state loss