sn2_smp.c

linux 内核源代码

				if ((deadlock = wait_piowc())) {
					if (flush_opt == 1)
						goto done;
					sn2_ptc_deadlock_recovery(nasids, ibegin, i, mynasid, ptc0, data0, ptc1, data1);
					if (reset_max_active_on_deadlock())
						max_active = 1;
				}
				active = 0;
				ibegin = i + 1;
			}
		}
		start += (1UL << nbits);
	} while (start < end);

done:
	itc2 = ia64_get_itc() - itc2;
	__get_cpu_var(ptcstats).shub_itc_clocks += itc2;
	if (itc2 > __get_cpu_var(ptcstats).shub_itc_clocks_max)
		__get_cpu_var(ptcstats).shub_itc_clocks_max = itc2;

	if (old_rr) {
		ia64_set_rr(start, old_rr);
		ia64_srlz_d();
	}

	spin_unlock_irqrestore(PTC_LOCK(shub1), flags);

	if (flush_opt == 1 && deadlock) {
		__get_cpu_var(ptcstats).deadlocks++;
		sn2_ipi_flush_all_tlb(mm);
	}

	preempt_enable();
}

/*
 * sn2_ptc_deadlock_recovery
 *
 * Recover from PTC deadlocks conditions. Recovery requires stepping thru each 
 * TLB flush transaction.  The recovery sequence is somewhat tricky & is
 * coded in assembly language.
 */

void
sn2_ptc_deadlock_recovery(short *nasids, short ib, short ie, int mynasid,
			  volatile unsigned long *ptc0, unsigned long data0,
			  volatile unsigned long *ptc1, unsigned long data1)
{
	short nasid, i;
	unsigned long *piows, zeroval, n;

	__get_cpu_var(ptcstats).deadlocks++;

	piows = (unsigned long *) pda->pio_write_status_addr;
	zeroval = pda->pio_write_status_val;


	for (i=ib; i <= ie; i++) {
		nasid = nasids[i];
		if (local_node_uses_ptc_ga(is_shub1()) && nasid == mynasid)
			continue;
		ptc0 = CHANGE_NASID(nasid, ptc0);
		if (ptc1)
			ptc1 = CHANGE_NASID(nasid, ptc1);

		n = sn2_ptc_deadlock_recovery_core(ptc0, data0, ptc1, data1, piows, zeroval);
		__get_cpu_var(ptcstats).deadlocks2 += n;
	}

}

/**
 * sn_send_IPI_phys - send an IPI to a Nasid and slice
 * @nasid: nasid to receive the interrupt (may be outside partition)
 * @physid: physical cpuid to receive the interrupt.
 * @vector: command to send
 * @delivery_mode: delivery mechanism
 *
 * Sends an IPI (interprocessor interrupt) to the processor specified by
 * @physid
 *
 * @delivery_mode can be one of the following
 *
 * %IA64_IPI_DM_INT - pend an interrupt
 * %IA64_IPI_DM_PMI - pend a PMI
 * %IA64_IPI_DM_NMI - pend an NMI
 * %IA64_IPI_DM_INIT - pend an INIT interrupt
 */
void sn_send_IPI_phys(int nasid, long physid, int vector, int delivery_mode)
{
	long val;
	unsigned long flags = 0;
	volatile long *p;

	p = (long *)GLOBAL_MMR_PHYS_ADDR(nasid, SH_IPI_INT);
	val = (1UL << SH_IPI_INT_SEND_SHFT) |
	    (physid << SH_IPI_INT_PID_SHFT) |
	    ((long)delivery_mode << SH_IPI_INT_TYPE_SHFT) |
	    ((long)vector << SH_IPI_INT_IDX_SHFT) |
	    (0x000feeUL << SH_IPI_INT_BASE_SHFT);

	mb();
	if (enable_shub_wars_1_1()) {
		spin_lock_irqsave(&sn2_global_ptc_lock, flags);
	}
	pio_phys_write_mmr(p, val);
	if (enable_shub_wars_1_1()) {
		wait_piowc();
		spin_unlock_irqrestore(&sn2_global_ptc_lock, flags);
	}

}

EXPORT_SYMBOL(sn_send_IPI_phys);

/**
 * sn2_send_IPI - send an IPI to a processor
 * @cpuid: target of the IPI
 * @vector: command to send
 * @delivery_mode: delivery mechanism
 * @redirect: redirect the IPI?
 *
 * Sends an IPI (InterProcessor Interrupt) to the processor specified by
 * @cpuid.  @vector specifies the command to send, while @delivery_mode can 
 * be one of the following
 *
 * %IA64_IPI_DM_INT - pend an interrupt
 * %IA64_IPI_DM_PMI - pend a PMI
 * %IA64_IPI_DM_NMI - pend an NMI
 * %IA64_IPI_DM_INIT - pend an INIT interrupt
 */
void sn2_send_IPI(int cpuid, int vector, int delivery_mode, int redirect)
{
	long physid;
	int nasid;

	physid = cpu_physical_id(cpuid);
	nasid = cpuid_to_nasid(cpuid);

	/* the following is used only when starting cpus at boot time */
	if (unlikely(nasid == -1))
		ia64_sn_get_sapic_info(physid, &nasid, NULL, NULL);

	sn_send_IPI_phys(nasid, physid, vector, delivery_mode);
}

#ifdef CONFIG_HOTPLUG_CPU
/**
 * sn_cpu_disable_allowed - Determine if a CPU can be disabled.
 * @cpu - CPU that is requested to be disabled.
 *
 * CPU disable is only allowed on SHub2 systems running with a PROM
 * that supports CPU disable. It is not permitted to disable the boot processor.
 */
bool sn_cpu_disable_allowed(int cpu)
{
	if (is_shub2() && sn_prom_feature_available(PRF_CPU_DISABLE_SUPPORT)) {
		if (cpu != 0)
			return true;
		else
			printk(KERN_WARNING
			      "Disabling the boot processor is not allowed.\n");

	} else
		printk(KERN_WARNING
		       "CPU disable is not supported on this system.\n");

	return false;
}
#endif /* CONFIG_HOTPLUG_CPU */

#ifdef CONFIG_PROC_FS

#define PTC_BASENAME	"sgi_sn/ptc_statistics"

static void *sn2_ptc_seq_start(struct seq_file *file, loff_t * offset)
{
	if (*offset < NR_CPUS)
		return offset;
	return NULL;
}

static void *sn2_ptc_seq_next(struct seq_file *file, void *data, loff_t * offset)
{
	(*offset)++;
	if (*offset < NR_CPUS)
		return offset;
	return NULL;
}

static void sn2_ptc_seq_stop(struct seq_file *file, void *data)
{
}

static int sn2_ptc_seq_show(struct seq_file *file, void *data)
{
	struct ptc_stats *stat;
	int cpu;

	cpu = *(loff_t *) data;

	if (!cpu) {
		seq_printf(file,
			   "# cpu ptc_l newrid ptc_flushes nodes_flushed deadlocks lock_nsec shub_nsec shub_nsec_max not_my_mm deadlock2 ipi_fluches ipi_nsec\n");
		seq_printf(file, "# ptctest %d, flushopt %d\n", sn2_ptctest, sn2_flush_opt);
	}

	if (cpu < NR_CPUS && cpu_online(cpu)) {
		stat = &per_cpu(ptcstats, cpu);
		seq_printf(file, "cpu %d %ld %ld %ld %ld %ld %ld %ld %ld %ld %ld %ld %ld\n", cpu, stat->ptc_l,
				stat->change_rid, stat->shub_ptc_flushes, stat->nodes_flushed,
				stat->deadlocks,
				1000 * stat->lock_itc_clocks / per_cpu(cpu_info, cpu).cyc_per_usec,
				1000 * stat->shub_itc_clocks / per_cpu(cpu_info, cpu).cyc_per_usec,
				1000 * stat->shub_itc_clocks_max / per_cpu(cpu_info, cpu).cyc_per_usec,
				stat->shub_ptc_flushes_not_my_mm,
				stat->deadlocks2,
				stat->shub_ipi_flushes,
				1000 * stat->shub_ipi_flushes_itc_clocks / per_cpu(cpu_info, cpu).cyc_per_usec);
	}
	return 0;
}

static ssize_t sn2_ptc_proc_write(struct file *file, const char __user *user, size_t count, loff_t *data)
{
	int cpu;
	char optstr[64];

	if (copy_from_user(optstr, user, count))
		return -EFAULT;
	optstr[count - 1] = '\0';
	sn2_flush_opt = simple_strtoul(optstr, NULL, 0);

	for_each_online_cpu(cpu)
		memset(&per_cpu(ptcstats, cpu), 0, sizeof(struct ptc_stats));

	return count;
}

static struct seq_operations sn2_ptc_seq_ops = {
	.start = sn2_ptc_seq_start,
	.next = sn2_ptc_seq_next,
	.stop = sn2_ptc_seq_stop,
	.show = sn2_ptc_seq_show
};

static int sn2_ptc_proc_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &sn2_ptc_seq_ops);
}

static const struct file_operations proc_sn2_ptc_operations = {
	.open = sn2_ptc_proc_open,
	.read = seq_read,
	.write = sn2_ptc_proc_write,
	.llseek = seq_lseek,
	.release = seq_release,
};

static struct proc_dir_entry *proc_sn2_ptc;

static int __init sn2_ptc_init(void)
{
	if (!ia64_platform_is("sn2"))
		return 0;

	if (!(proc_sn2_ptc = create_proc_entry(PTC_BASENAME, 0444, NULL))) {
		printk(KERN_ERR "unable to create %s proc entry", PTC_BASENAME);
		return -EINVAL;
	}
	proc_sn2_ptc->proc_fops = &proc_sn2_ptc_operations;
	spin_lock_init(&sn2_global_ptc_lock);
	return 0;
}

static void __exit sn2_ptc_exit(void)
{
	remove_proc_entry(PTC_BASENAME, NULL);
}

module_init(sn2_ptc_init);
module_exit(sn2_ptc_exit);
#endif /* CONFIG_PROC_FS */