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Commit 755563bc authored by Paul Mackerras's avatar Paul Mackerras Committed by Michael Ellerman
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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: default avatarPaul Mackerras <paulus@samba.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 06e5801b

arch/powerpc/include/asm/ppc-opcode.h

+3 −0
Original line number Diff line number Diff line
@@ -153,6 +153,7 @@ 
#define PPC_INST_MFSPR_PVR_MASK		0xfc1fffff

#define PPC_INST_MFTMR			0x7c0002dc

#define PPC_INST_MSGSND			0x7c00019c

#define PPC_INST_MSGCLR			0x7c0001dc

#define PPC_INST_MSGSNDP		0x7c00011c

#define PPC_INST_MTTMR			0x7c0003dc

#define PPC_INST_NOP			0x60000000
@@ -309,6 +310,8 @@ 
					___PPC_RB(b) | __PPC_EH(eh))

#define PPC_MSGSND(b)		stringify_in_c(.long PPC_INST_MSGSND | \

					___PPC_RB(b))

#define PPC_MSGCLR(b)		stringify_in_c(.long PPC_INST_MSGCLR | \

					___PPC_RB(b))

#define PPC_MSGSNDP(b)		stringify_in_c(.long PPC_INST_MSGSNDP | \

					___PPC_RB(b))

#define PPC_POPCNTB(a, s)	stringify_in_c(.long PPC_INST_POPCNTB | \

arch/powerpc/include/asm/reg.h

+3 −0
Original line number Diff line number Diff line
@@ -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
Original line number Diff line number Diff line
@@ -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

+12 −2
Original line number Diff line number Diff line
@@ -33,6 +33,8 @@ 
#include <asm/runlatch.h>

#include <asm/code-patching.h>

#include <asm/dbell.h>

#include <asm/kvm_ppc.h>

#include <asm/ppc-opcode.h>



#include "powernv.h"
@@ -149,7 +151,7 @@ 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 +163,10 @@ 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 +197,14 @@ 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())