sb_tbprof.c

linux 内核源代码

	 * I need the core to mask these, but the interrupt mapper to
	 *  pass them through.  I am exploiting my knowledge that
	 *  cp0_status masks out IP[5]. krw
	 */
#if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
	__raw_writeq(K_BCM1480_INT_MAP_I3,
		     IOADDR(A_BCM1480_IMR_REGISTER(0, R_BCM1480_IMR_INTERRUPT_MAP_BASE_L) +
			    ((K_BCM1480_INT_PERF_CNT & 0x3f) << 3)));
#else
	__raw_writeq(K_INT_MAP_I3,
		     IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MAP_BASE) +
			    (K_INT_PERF_CNT << 3)));
#endif

	/* Initialize address traps */
	__raw_writeq(0, IOADDR(A_ADDR_TRAP_UP_0));
	__raw_writeq(0, IOADDR(A_ADDR_TRAP_UP_1));
	__raw_writeq(0, IOADDR(A_ADDR_TRAP_UP_2));
	__raw_writeq(0, IOADDR(A_ADDR_TRAP_UP_3));

	__raw_writeq(0, IOADDR(A_ADDR_TRAP_DOWN_0));
	__raw_writeq(0, IOADDR(A_ADDR_TRAP_DOWN_1));
	__raw_writeq(0, IOADDR(A_ADDR_TRAP_DOWN_2));
	__raw_writeq(0, IOADDR(A_ADDR_TRAP_DOWN_3));

	__raw_writeq(0, IOADDR(A_ADDR_TRAP_CFG_0));
	__raw_writeq(0, IOADDR(A_ADDR_TRAP_CFG_1));
	__raw_writeq(0, IOADDR(A_ADDR_TRAP_CFG_2));
	__raw_writeq(0, IOADDR(A_ADDR_TRAP_CFG_3));

	/* Initialize Trace Event 0-7 */
	/*				when interrupt  */
	__raw_writeq(M_SCD_TREVT_INTERRUPT, IOADDR(A_SCD_TRACE_EVENT_0));
	__raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_1));
	__raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_2));
	__raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_3));
	__raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_4));
	__raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_5));
	__raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_6));
	__raw_writeq(0, IOADDR(A_SCD_TRACE_EVENT_7));

	/* Initialize Trace Sequence 0-7 */
	/*				     Start on event 0 (interrupt) */
	__raw_writeq(V_SCD_TRSEQ_FUNC_START | 0x0fff,
		     IOADDR(A_SCD_TRACE_SEQUENCE_0));
	/*			  dsamp when d used | asamp when a used */
	__raw_writeq(M_SCD_TRSEQ_ASAMPLE | M_SCD_TRSEQ_DSAMPLE |
		     K_SCD_TRSEQ_TRIGGER_ALL,
		     IOADDR(A_SCD_TRACE_SEQUENCE_1));
	__raw_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_2));
	__raw_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_3));
	__raw_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_4));
	__raw_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_5));
	__raw_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_6));
	__raw_writeq(0, IOADDR(A_SCD_TRACE_SEQUENCE_7));

	/* Now indicate the PERF_CNT interrupt as a trace-relevant interrupt */
#if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
	__raw_writeq(1ULL << (K_BCM1480_INT_PERF_CNT & 0x3f),
		     IOADDR(A_BCM1480_IMR_REGISTER(0, R_BCM1480_IMR_INTERRUPT_TRACE_L)));
#else
	__raw_writeq(1ULL << K_INT_PERF_CNT,
		     IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_TRACE)));
#endif
	arm_tb();

	pr_debug(DEVNAME ": done starting\n");

	return 0;
}

static int sbprof_zbprof_stop(void)
{
	int err = 0;

	pr_debug(DEVNAME ": stopping\n");

	if (sbp.tb_enable) {
		/*
		 * XXXKW there is a window here where the intr handler may run,
		 * see the disable, and do the wake_up before this sleep
		 * happens.
		 */
		pr_debug(DEVNAME ": wait for disarm\n");
		err = wait_event_interruptible(sbp.tb_sync, !sbp.tb_armed);
		pr_debug(DEVNAME ": disarm complete, stat %d\n", err);

		if (err)
			return err;

		sbp.tb_enable = 0;
		free_irq(K_INT_TRACE_FREEZE, &sbp);
		free_irq(K_INT_PERF_CNT, &sbp);
	}

	pr_debug(DEVNAME ": done stopping\n");

	return err;
}

static int sbprof_tb_open(struct inode *inode, struct file *filp)
{
	int minor;

	minor = iminor(inode);
	if (minor != 0)
		return -ENODEV;

	if (xchg(&sbp.open, SB_OPENING) != SB_CLOSED)
		return -EBUSY;

	memset(&sbp, 0, sizeof(struct sbprof_tb));
	sbp.sbprof_tbbuf = vmalloc(MAX_TBSAMPLE_BYTES);
	if (!sbp.sbprof_tbbuf)
		return -ENOMEM;
	memset(sbp.sbprof_tbbuf, 0, MAX_TBSAMPLE_BYTES);
	init_waitqueue_head(&sbp.tb_sync);
	init_waitqueue_head(&sbp.tb_read);
	mutex_init(&sbp.lock);

	sbp.open = SB_OPEN;

	return 0;
}

static int sbprof_tb_release(struct inode *inode, struct file *filp)
{
	int minor;

	minor = iminor(inode);
	if (minor != 0 || !sbp.open)
		return -ENODEV;

	mutex_lock(&sbp.lock);

	if (sbp.tb_armed || sbp.tb_enable)
		sbprof_zbprof_stop();

	vfree(sbp.sbprof_tbbuf);
	sbp.open = 0;

	mutex_unlock(&sbp.lock);

	return 0;
}

static ssize_t sbprof_tb_read(struct file *filp, char *buf,
			      size_t size, loff_t *offp)
{
	int cur_sample, sample_off, cur_count, sample_left;
	char *src;
	int   count   =	 0;
	char *dest    =	 buf;
	long  cur_off = *offp;

	if (!access_ok(VERIFY_WRITE, buf, size))
		return -EFAULT;

	mutex_lock(&sbp.lock);

	count = 0;
	cur_sample = cur_off / TB_SAMPLE_SIZE;
	sample_off = cur_off % TB_SAMPLE_SIZE;
	sample_left = TB_SAMPLE_SIZE - sample_off;

	while (size && (cur_sample < sbp.next_tb_sample)) {
		int err;

		cur_count = size < sample_left ? size : sample_left;
		src = (char *)(((long)sbp.sbprof_tbbuf[cur_sample])+sample_off);
		err = __copy_to_user(dest, src, cur_count);
		if (err) {
			*offp = cur_off + cur_count - err;
			mutex_unlock(&sbp.lock);
			return err;
		}
		pr_debug(DEVNAME ": read from sample %d, %d bytes\n",
		         cur_sample, cur_count);
		size -= cur_count;
		sample_left -= cur_count;
		if (!sample_left) {
			cur_sample++;
			sample_off = 0;
			sample_left = TB_SAMPLE_SIZE;
		} else {
			sample_off += cur_count;
		}
		cur_off += cur_count;
		dest += cur_count;
		count += cur_count;
	}
	*offp = cur_off;
	mutex_unlock(&sbp.lock);

	return count;
}

static long sbprof_tb_ioctl(struct file *filp,
			    unsigned int command,
			    unsigned long arg)
{
	int err = 0;

	switch (command) {
	case SBPROF_ZBSTART:
		mutex_lock(&sbp.lock);
		err = sbprof_zbprof_start(filp);
		mutex_unlock(&sbp.lock);
		break;

	case SBPROF_ZBSTOP:
		mutex_lock(&sbp.lock);
		err = sbprof_zbprof_stop();
		mutex_unlock(&sbp.lock);
		break;

	case SBPROF_ZBWAITFULL: {
		err = wait_event_interruptible(sbp.tb_read, TB_FULL);
		if (err)
			break;

		err = put_user(TB_FULL, (int *) arg);
		break;
	}

	default:
		err = -EINVAL;
		break;
	}

	return err;
}

static const struct file_operations sbprof_tb_fops = {
	.owner		= THIS_MODULE,
	.open		= sbprof_tb_open,
	.release	= sbprof_tb_release,
	.read		= sbprof_tb_read,
	.unlocked_ioctl	= sbprof_tb_ioctl,
	.compat_ioctl	= sbprof_tb_ioctl,
	.mmap		= NULL,
};

static struct class *tb_class;
static struct device *tb_dev;

static int __init sbprof_tb_init(void)
{
	struct device *dev;
	struct class *tbc;
	int err;

	if (register_chrdev(SBPROF_TB_MAJOR, DEVNAME, &sbprof_tb_fops)) {
		printk(KERN_WARNING DEVNAME ": initialization failed (dev %d)\n",
		       SBPROF_TB_MAJOR);
		return -EIO;
	}

	tbc = class_create(THIS_MODULE, "sb_tracebuffer");
	if (IS_ERR(tbc)) {
		err = PTR_ERR(tbc);
		goto out_chrdev;
	}

	tb_class = tbc;

	dev = device_create(tbc, NULL, MKDEV(SBPROF_TB_MAJOR, 0), "tb");
	if (IS_ERR(dev)) {
		err = PTR_ERR(dev);
		goto out_class;
	}
	tb_dev = dev;

	sbp.open = 0;
	tb_period = zbbus_mhz * 10000LL;
	pr_info(DEVNAME ": initialized - tb_period = %lld\n",
		(long long) tb_period);
	return 0;

out_class:
	class_destroy(tb_class);
out_chrdev:
	unregister_chrdev(SBPROF_TB_MAJOR, DEVNAME);

	return err;
}

static void __exit sbprof_tb_cleanup(void)
{
	device_destroy(tb_class, MKDEV(SBPROF_TB_MAJOR, 0));
	unregister_chrdev(SBPROF_TB_MAJOR, DEVNAME);
	class_destroy(tb_class);
}

module_init(sbprof_tb_init);
module_exit(sbprof_tb_cleanup);

MODULE_ALIAS_CHARDEV_MAJOR(SBPROF_TB_MAJOR);
MODULE_AUTHOR("Ralf Baechle <[e-mail]>");
MODULE_LICENSE("GPL");