MIPS: SMTC: Avoid queing multiple reschedule IPIs (2e41f91d) · Commits · e / devices / android_kernel_sony_msm8994

arch/mips/include/asm/smtc_ipi.h

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -45,6 +45,7 @@ struct smtc_ipi_q {
	spinlock_t lock;		spinlock_t lock;
	struct smtc_ipi *tail;		struct smtc_ipi *tail;
	int depth;		int depth;
			int resched_flag; /* reschedule already queued */
	};		};

	static inline void smtc_ipi_nq(struct smtc_ipi_q q, struct smtc_ipi p)		static inline void smtc_ipi_nq(struct smtc_ipi_q q, struct smtc_ipi p)

arch/mips/kernel/smtc.c

+30 −4

Original line number	Original line	Diff line number	Diff line
	@@ -75,7 +75,6 @@ unsigned long irq_hwmask[NR_IRQS];

	asiduse smtc_live_asid[MAX_SMTC_TLBS][MAX_SMTC_ASIDS];		asiduse smtc_live_asid[MAX_SMTC_TLBS][MAX_SMTC_ASIDS];


	/*		/*
	* Number of InterProcessor Interrupt (IPI) message buffers to allocate		* Number of InterProcessor Interrupt (IPI) message buffers to allocate
	*/		*/
	@@ -388,6 +387,7 @@ void smtc_prepare_cpus(int cpus)
	IPIQ[i].head = IPIQ[i].tail = NULL;		IPIQ[i].head = IPIQ[i].tail = NULL;
	spin_lock_init(&IPIQ[i].lock);		spin_lock_init(&IPIQ[i].lock);
	IPIQ[i].depth = 0;		IPIQ[i].depth = 0;
			IPIQ[i].resched_flag = 0; /* No reschedules queued initially */
	}		}

	/* cpu_data index starts at zero */		/* cpu_data index starts at zero */
	@@ -741,11 +741,24 @@ void smtc_forward_irq(unsigned int irq)
	static void smtc_ipi_qdump(void)		static void smtc_ipi_qdump(void)
	{		{
	int i;		int i;
			struct smtc_ipi *temp;

	for (i = 0; i < NR_CPUS ;i++) {		for (i = 0; i < NR_CPUS ;i++) {
	printk("IPIQ[%d]: head = 0x%x, tail = 0x%x, depth = %d\n",		pr_info("IPIQ[%d]: head = 0x%x, tail = 0x%x, depth = %d\n",
	i, (unsigned)IPIQ[i].head, (unsigned)IPIQ[i].tail,		i, (unsigned)IPIQ[i].head, (unsigned)IPIQ[i].tail,
	IPIQ[i].depth);		IPIQ[i].depth);
			temp = IPIQ[i].head;

			while (temp != IPIQ[i].tail) {
			pr_debug("%d %d %d: ", temp->type, temp->dest,
			(int)temp->arg);
			#ifdef SMTC_IPI_DEBUG
			pr_debug("%u %lu\n", temp->sender, temp->stamp);
			#else
			pr_debug("\n");
			#endif
			temp = temp->flink;
			}
	}		}
	}		}

	@@ -784,11 +797,16 @@ void smtc_send_ipi(int cpu, int type, unsigned int action)
	int mtflags;		int mtflags;
	unsigned long tcrestart;		unsigned long tcrestart;
	extern void r4k_wait_irqoff(void), __pastwait(void);		extern void r4k_wait_irqoff(void), __pastwait(void);
			int set_resched_flag = (type == LINUX_SMP_IPI &&
			action == SMP_RESCHEDULE_YOURSELF);

	if (cpu == smp_processor_id()) {		if (cpu == smp_processor_id()) {
	printk("Cannot Send IPI to self!\n");		printk("Cannot Send IPI to self!\n");
	return;		return;
	}		}
			if (set_resched_flag && IPIQ[cpu].resched_flag != 0)
			return; /* There is a reschedule queued already */

	/* Set up a descriptor, to be delivered either promptly or queued */		/* Set up a descriptor, to be delivered either promptly or queued */
	pipi = smtc_ipi_dq(&freeIPIq);		pipi = smtc_ipi_dq(&freeIPIq);
	if (pipi == NULL) {		if (pipi == NULL) {
	@@ -801,6 +819,7 @@ void smtc_send_ipi(int cpu, int type, unsigned int action)
	pipi->dest = cpu;		pipi->dest = cpu;
	if (cpu_data[cpu].vpe_id != cpu_data[smp_processor_id()].vpe_id) {		if (cpu_data[cpu].vpe_id != cpu_data[smp_processor_id()].vpe_id) {
	/* If not on same VPE, enqueue and send cross-VPE interrupt */		/* If not on same VPE, enqueue and send cross-VPE interrupt */
			IPIQ[cpu].resched_flag \|= set_resched_flag;
	smtc_ipi_nq(&IPIQ[cpu], pipi);		smtc_ipi_nq(&IPIQ[cpu], pipi);
	LOCK_CORE_PRA();		LOCK_CORE_PRA();
	settc(cpu_data[cpu].tc_id);		settc(cpu_data[cpu].tc_id);
	@@ -847,6 +866,7 @@ void smtc_send_ipi(int cpu, int type, unsigned int action)
	*/		*/
	write_tc_c0_tchalt(0);		write_tc_c0_tchalt(0);
	UNLOCK_CORE_PRA();		UNLOCK_CORE_PRA();
			IPIQ[cpu].resched_flag \|= set_resched_flag;
	smtc_ipi_nq(&IPIQ[cpu], pipi);		smtc_ipi_nq(&IPIQ[cpu], pipi);
	} else {		} else {
	postdirect:		postdirect:
	@@ -996,12 +1016,15 @@ void deferred_smtc_ipi(void)
	* already enabled.		* already enabled.
	*/		*/
	local_irq_save(flags);		local_irq_save(flags);

	spin_lock(&q->lock);		spin_lock(&q->lock);
	pipi = __smtc_ipi_dq(q);		pipi = __smtc_ipi_dq(q);
	spin_unlock(&q->lock);		spin_unlock(&q->lock);
	if (pipi != NULL)		if (pipi != NULL) {
			if (pipi->type == LINUX_SMP_IPI &&
			(int)pipi->arg == SMP_RESCHEDULE_YOURSELF)
			IPIQ[cpu].resched_flag = 0;
	ipi_decode(pipi);		ipi_decode(pipi);
			}
	/*		/*
	* The use of the __raw_local restore isn't		* The use of the __raw_local restore isn't
	* as obviously necessary here as in smtc_ipi_replay(),		* as obviously necessary here as in smtc_ipi_replay(),
	@@ -1082,6 +1105,9 @@ static irqreturn_t ipi_interrupt(int irq, void *dev_idm)
	* with interrupts off		* with interrupts off
	*/		*/
	local_irq_save(flags);		local_irq_save(flags);
			if (pipi->type == LINUX_SMP_IPI &&
			(int)pipi->arg == SMP_RESCHEDULE_YOURSELF)
			IPIQ[cpu].resched_flag = 0;
	ipi_decode(pipi);		ipi_decode(pipi);
	local_irq_restore(flags);		local_irq_restore(flags);
	}		}