powerpc/powernv: Fixes for hypervisor doorbell handling
PATCH 1/1 powerpc/powernv: Fixes for hypervisor doorbell handling
Since we can now use hypervisor doorbells for host IPIs, this makes sure we clear the host IPI flag when taking a doorbell interrupt, and clears any pending doorbell IPI in pnv_smp_cpu_kill_self() (as we already do for IPIs sent via the XICS interrupt controller). Otherwise if there did happen to be a leftover pending doorbell interrupt for an offline CPU thread for any reason, it would prevent that thread from going into a power-saving mode; it would instead keep waking up because of the interrupt.
Signed-off-by Paul Mackerras <[email protected]>
--- arch/powerpc/include/asm/reg.h | 3 +++ arch/powerpc/kernel/dbell.c | 2 ++ arch/powerpc/platforms/powernv/smp.c | 13 +++++++++++-- 3 files changed, 16 insertions(+), 2 deletions(-)
arch/powerpc/include/asm/reg.h +3 -0
@@ -608,13 +608,16 @@#define SRR1_ISI_N_OR_G 0x10000000/* ISI: Access is no-exec or G */ #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 */ #define SRR1_WAKESYSERR 0x00300000/* System error */ #define SRR1_WAKEEE 0x00200000/* External interrupt */ #define SRR1_WAKEMT 0x00280000/* mtctrl */ #define SRR1_WAKEHMI 0x00280000/* Hypervisor maintenance */ #define SRR1_WAKEDEC 0x00180000/* Decrementer interrupt */ +#define SRR1_WAKEDBELL 0x00140000/* Privileged doorbell on P8 */ #define SRR1_WAKETHERM 0x00100000/* Thermal management interrupt */ #define SRR1_WAKERESET 0x00100000/* System reset */ +#define SRR1_WAKEHDBELL 0x000c0000/* Hypervisor doorbell on P8 */ #define SRR1_WAKESTATE 0x00030000/* Powersave exit mask [46:47] */ #define SRR1_WS_DEEPEST 0x00030000/* Some resources not maintained, * may not be recoverable */
arch/powerpc/kernel/dbell.c +2 -0
@@ -17,6 +17,7 @@#include <asm/dbell.h> #include <asm/irq_regs.h> +#include <asm/kvm_ppc.h> #ifdef CONFIG_SMP void doorbell_setup_this_cpu (void )
@@ -41,6 +42,7 @@ void doorbell_exception(struct pt_regs *regs)may_hard_irq_enable (); +kvmppc_set_host_ipi (smp_processor_id (),0 );__this_cpu_inc (irq_stat.doorbell_irqs);smp_ipi_demux ();
arch/powerpc/platforms/powernv/smp.c +11 -2
@@ -33,6 +33,7 @@#include <asm/runlatch.h> #include <asm/code-patching.h> #include <asm/dbell.h> +#include <asm/kvm_ppc.h> #include "powernv.h"
@@ -149,7 +150,7 @@ static int pnv_smp_cpu_disable(void)static void pnv_smp_cpu_kill_self (void ) {unsigned int cpu; -unsigned long srr1; +unsigned long srr1, wmask;u32 idle_states;/* Standard hot unplug procedure */
@@ -161,6 +162,10 @@ static void pnv_smp_cpu_kill_self(void)generic_set_cpu_dead (cpu);smp_wmb (); + wmask =SRR1_WAKEMASK ; +if (cpu_has_feature (CPU_FTR_ARCH_207S )) + wmask =SRR1_WAKEMASK_P8 ; + idle_states =pnv_get_supported_cpuidle_states ();/* We don't want to take decrementer interrupts while we are offline, * so clear LPCR:PECE1. We keep PECE2 enabled.
@@ -191,10 +196,14 @@ static void pnv_smp_cpu_kill_self(void)* having finished executing in a KVM guest, then srr1 * contains 0. */ -if ((srr1 &SRR1_WAKEMASK ) ==SRR1_WAKEEE ) { +if ((srr1 & wmask) ==SRR1_WAKEEE ) {icp_native_flush_interrupt (); local_paca->irq_happened &=PACA_IRQ_HARD_DIS ;smp_mb (); + }else if ((srr1 & wmask) ==SRR1_WAKEHDBELL ) { +unsigned long msg =PPC_DBELL_TYPE (PPC_DBELL_SERVER ); + asm volatile(PPC_MSGCLR(%0) : : "r" (msg)); +kvmppc_set_host_ipi (cpu,0 ); }if (cpu_core_split_required ())
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2.1.4