diff options
| -rw-r--r-- | arch/powerpc/include/asm/processor.h | 2 | ||||
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 2 | ||||
| -rw-r--r-- | arch/powerpc/kernel/idle_power7.S | 12 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_rmhandlers.S | 54 | ||||
| -rw-r--r-- | arch/powerpc/platforms/powernv/smp.c | 23 |
5 files changed, 68 insertions, 25 deletions
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h index dda7ac4c80b..29c3798cf80 100644 --- a/arch/powerpc/include/asm/processor.h +++ b/arch/powerpc/include/asm/processor.h @@ -451,7 +451,7 @@ 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(int check_irq); +extern unsigned long 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/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 6213f494f40..db08382e19f 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -131,6 +131,8 @@ BEGIN_FTR_SECTION 1: #endif + /* Return SRR1 from power7_nap() */ + mfspr r3,SPRN_SRR1 beq cr1,2f b power7_wakeup_noloss 2: b power7_wakeup_loss diff --git a/arch/powerpc/kernel/idle_power7.S b/arch/powerpc/kernel/idle_power7.S index c0754bbf811..18c0687e5ab 100644 --- a/arch/powerpc/kernel/idle_power7.S +++ b/arch/powerpc/kernel/idle_power7.S @@ -212,6 +212,10 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) mtspr SPRN_SRR0,r5 rfid +/* + * R3 here contains the value that will be returned to the caller + * of power7_nap. + */ _GLOBAL(power7_wakeup_loss) ld r1,PACAR1(r13) BEGIN_FTR_SECTION @@ -219,15 +223,19 @@ BEGIN_FTR_SECTION END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) REST_NVGPRS(r1) REST_GPR(2, r1) - ld r3,_CCR(r1) + ld r6,_CCR(r1) ld r4,_MSR(r1) ld r5,_NIP(r1) addi r1,r1,INT_FRAME_SIZE - mtcr r3 + mtcr r6 mtspr SPRN_SRR1,r4 mtspr SPRN_SRR0,r5 rfid +/* + * R3 here contains the value that will be returned to the caller + * of power7_nap. + */ _GLOBAL(power7_wakeup_noloss) lbz r0,PACA_NAPSTATELOST(r13) cmpwi r0,0 diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index edb2ccdbb2b..65c105b17a2 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -201,8 +201,6 @@ kvmppc_primary_no_guest: bge kvm_novcpu_exit /* another thread already exiting */ li r3, NAPPING_NOVCPU stb r3, HSTATE_NAPPING(r13) - li r3, 1 - stb r3, HSTATE_HWTHREAD_REQ(r13) b kvm_do_nap @@ -293,6 +291,8 @@ kvm_start_guest: /* if we have no vcpu to run, go back to sleep */ beq kvm_no_guest +kvm_secondary_got_guest: + /* Set HSTATE_DSCR(r13) to something sensible */ ld r6, PACA_DSCR(r13) std r6, HSTATE_DSCR(r13) @@ -318,27 +318,46 @@ kvm_start_guest: stwcx. r3, 0, r4 bne 51b +/* + * At this point we have finished executing in the guest. + * We need to wait for hwthread_req to become zero, since + * we may not turn on the MMU while hwthread_req is non-zero. + * While waiting we also need to check if we get given a vcpu to run. + */ kvm_no_guest: - li r0, KVM_HWTHREAD_IN_NAP + lbz r3, HSTATE_HWTHREAD_REQ(r13) + cmpwi r3, 0 + bne 53f + HMT_MEDIUM + li r0, KVM_HWTHREAD_IN_KERNEL stb r0, HSTATE_HWTHREAD_STATE(r13) -kvm_do_nap: - /* Clear the runlatch bit before napping */ - mfspr r2, SPRN_CTRLF - clrrdi r2, r2, 1 - mtspr SPRN_CTRLT, r2 - + /* need to recheck hwthread_req after a barrier, to avoid race */ + sync + lbz r3, HSTATE_HWTHREAD_REQ(r13) + cmpwi r3, 0 + bne 54f +/* + * We jump to power7_wakeup_loss, which will return to the caller + * of power7_nap in the powernv cpu offline loop. The value we + * put in r3 becomes the return value for power7_nap. + */ li r3, LPCR_PECE0 mfspr r4, SPRN_LPCR rlwimi r4, r3, 0, LPCR_PECE0 | LPCR_PECE1 mtspr SPRN_LPCR, r4 - isync - std r0, HSTATE_SCRATCH0(r13) - ptesync - ld r0, HSTATE_SCRATCH0(r13) -1: cmpd r0, r0 - bne 1b - nap - b . + li r3, 0 + b power7_wakeup_loss + +53: HMT_LOW + ld r4, HSTATE_KVM_VCPU(r13) + cmpdi r4, 0 + beq kvm_no_guest + HMT_MEDIUM + b kvm_secondary_got_guest + +54: li r0, KVM_HWTHREAD_IN_KVM + stb r0, HSTATE_HWTHREAD_STATE(r13) + b kvm_no_guest /****************************************************************************** * * @@ -2172,6 +2191,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_206) * occurs, with PECE1, PECE0 and PECEDP set in LPCR. Also clear the * runlatch bit before napping. */ +kvm_do_nap: mfspr r2, SPRN_CTRLF clrrdi r2, r2, 1 mtspr SPRN_CTRLT, r2 diff --git a/arch/powerpc/platforms/powernv/smp.c b/arch/powerpc/platforms/powernv/smp.c index 4753958cd50..b716f666e48 100644 --- a/arch/powerpc/platforms/powernv/smp.c +++ b/arch/powerpc/platforms/powernv/smp.c @@ -149,6 +149,7 @@ static int pnv_smp_cpu_disable(void) static void pnv_smp_cpu_kill_self(void) { unsigned int cpu; + unsigned long srr1; /* Standard hot unplug procedure */ local_irq_disable(); @@ -165,13 +166,25 @@ 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(1); + srr1 = power7_nap(1); ppc64_runlatch_on(); - /* Clear the IPI that woke us up */ - icp_native_flush_interrupt(); - local_paca->irq_happened &= PACA_IRQ_HARD_DIS; - mb(); + /* + * If the SRR1 value indicates that we woke up due to + * an external interrupt, then clear the interrupt. + * We clear the interrupt before checking for the + * reason, so as to avoid a race where we wake up for + * some other reason, find nothing and clear the interrupt + * just as some other cpu is sending us an interrupt. + * If we returned from power7_nap as a result of + * having finished executing in a KVM guest, then srr1 + * contains 0. + */ + if ((srr1 & SRR1_WAKEMASK) == SRR1_WAKEEE) { + icp_native_flush_interrupt(); + local_paca->irq_happened &= PACA_IRQ_HARD_DIS; + smp_mb(); + } if (cpu_core_split_required()) continue; |