[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / arm / kernel / etm.c

/*
 * linux/arch/arm/kernel/etm.c
 *
 * Driver for ARM's Embedded Trace Macrocell and Embedded Trace Buffer.
 *
 * Copyright (C) 2009 Nokia Corporation.
 * Alexander Shishkin
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/io.h>
#include <linux/sysrq.h>
#include <linux/device.h>
#include <linux/clk.h>
#include <linux/amba/bus.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/miscdevice.h>
#include <linux/vmalloc.h>
#include <linux/mutex.h>
#include <asm/hardware/coresight.h>
#include <asm/sections.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Alexander Shishkin");

/*
 * ETM tracer state
 */
struct tracectx {
	unsigned int	etb_bufsz;
	void __iomem	*etb_regs;
	void __iomem	*etm_regs;
	unsigned long	flags;
	int		ncmppairs;
	int		etm_portsz;
	struct device	*dev;
	struct clk	*emu_clk;
	struct mutex	mutex;
};

static struct tracectx tracer;

static inline bool trace_isrunning(struct tracectx *t)
{
	return !!(t->flags & TRACER_RUNNING);
}

static int etm_setup_address_range(struct tracectx *t, int n,
		unsigned long start, unsigned long end, int exclude, int data)
{
	u32 flags = ETMAAT_ARM | ETMAAT_IGNCONTEXTID | ETMAAT_NSONLY | \
		    ETMAAT_NOVALCMP;

	if (n < 1 || n > t->ncmppairs)
		return -EINVAL;

	/* comparators and ranges are numbered starting with 1 as opposed
	 * to bits in a word */
	n--;

	if (data)
		flags |= ETMAAT_DLOADSTORE;
	else
		flags |= ETMAAT_IEXEC;

	/* first comparator for the range */
	etm_writel(t, flags, ETMR_COMP_ACC_TYPE(n * 2));
	etm_writel(t, start, ETMR_COMP_VAL(n * 2));

	/* second comparator is right next to it */
	etm_writel(t, flags, ETMR_COMP_ACC_TYPE(n * 2 + 1));
	etm_writel(t, end, ETMR_COMP_VAL(n * 2 + 1));

	flags = exclude ? ETMTE_INCLEXCL : 0;
	etm_writel(t, flags | (1 << n), ETMR_TRACEENCTRL);

	return 0;
}

static int trace_start(struct tracectx *t)
{
	u32 v;
	unsigned long timeout = TRACER_TIMEOUT;

	etb_unlock(t);

	etb_writel(t, 0, ETBR_FORMATTERCTRL);
	etb_writel(t, 1, ETBR_CTRL);

	etb_lock(t);

	/* configure etm */
	v = ETMCTRL_OPTS | ETMCTRL_PROGRAM | ETMCTRL_PORTSIZE(t->etm_portsz);

	if (t->flags & TRACER_CYCLE_ACC)
		v |= ETMCTRL_CYCLEACCURATE;

	etm_unlock(t);

	etm_writel(t, v, ETMR_CTRL);

	while (!(etm_readl(t, ETMR_CTRL) & ETMCTRL_PROGRAM) && --timeout)
		;
	if (!timeout) {
		dev_dbg(t->dev, "Waiting for progbit to assert timed out\n");
		etm_lock(t);
		return -EFAULT;
	}

	etm_setup_address_range(t, 1, (unsigned long)_stext,
			(unsigned long)_etext, 0, 0);
	etm_writel(t, 0, ETMR_TRACEENCTRL2);
	etm_writel(t, 0, ETMR_TRACESSCTRL);
	etm_writel(t, 0x6f, ETMR_TRACEENEVT);

	v &= ~ETMCTRL_PROGRAM;
	v |= ETMCTRL_PORTSEL;

	etm_writel(t, v, ETMR_CTRL);

	timeout = TRACER_TIMEOUT;
	while (etm_readl(t, ETMR_CTRL) & ETMCTRL_PROGRAM && --timeout)
		;
	if (!timeout) {
		dev_dbg(t->dev, "Waiting for progbit to deassert timed out\n");
		etm_lock(t);
		return -EFAULT;
	}

	etm_lock(t);

	t->flags |= TRACER_RUNNING;

	return 0;
}

static int trace_stop(struct tracectx *t)
{
	unsigned long timeout = TRACER_TIMEOUT;

	etm_unlock(t);

	etm_writel(t, 0x440, ETMR_CTRL);
	while (!(etm_readl(t, ETMR_CTRL) & ETMCTRL_PROGRAM) && --timeout)
		;
	if (!timeout) {
		dev_dbg(t->dev, "Waiting for progbit to assert timed out\n");
		etm_lock(t);
		return -EFAULT;
	}

	etm_lock(t);

	etb_unlock(t);
	etb_writel(t, ETBFF_MANUAL_FLUSH, ETBR_FORMATTERCTRL);

	timeout = TRACER_TIMEOUT;
	while (etb_readl(t, ETBR_FORMATTERCTRL) &
			ETBFF_MANUAL_FLUSH && --timeout)
		;
	if (!timeout) {
		dev_dbg(t->dev, "Waiting for formatter flush to commence "
				"timed out\n");
		etb_lock(t);
		return -EFAULT;
	}

	etb_writel(t, 0, ETBR_CTRL);

	etb_lock(t);

	t->flags &= ~TRACER_RUNNING;

	return 0;
}

static int etb_getdatalen(struct tracectx *t)
{
	u32 v;
	int rp, wp;

	v = etb_readl(t, ETBR_STATUS);

	if (v & 1)
		return t->etb_bufsz;

	rp = etb_readl(t, ETBR_READADDR);
	wp = etb_readl(t, ETBR_WRITEADDR);

	if (rp > wp) {
		etb_writel(t, 0, ETBR_READADDR);
		etb_writel(t, 0, ETBR_WRITEADDR);

		return 0;
	}

	return wp - rp;
}

/* sysrq+v will always stop the running trace and leave it at that */
static void etm_dump(void)
{
	struct tracectx *t = &tracer;
	u32 first = 0;
	int length;

	if (!t->etb_regs) {
		printk(KERN_INFO "No tracing hardware found\n");
		return;
	}

	if (trace_isrunning(t))
		trace_stop(t);

	etb_unlock(t);

	length = etb_getdatalen(t);

	if (length == t->etb_bufsz)
		first = etb_readl(t, ETBR_WRITEADDR);

	etb_writel(t, first, ETBR_READADDR);

	printk(KERN_INFO "Trace buffer contents length: %d\n", length);
	printk(KERN_INFO "--- ETB buffer begin ---\n");
	for (; length; length--)
		printk("%08x", cpu_to_be32(etb_readl(t, ETBR_READMEM)));
	printk(KERN_INFO "\n--- ETB buffer end ---\n");

	/* deassert the overflow bit */
	etb_writel(t, 1, ETBR_CTRL);
	etb_writel(t, 0, ETBR_CTRL);

	etb_writel(t, 0, ETBR_TRIGGERCOUNT);
	etb_writel(t, 0, ETBR_READADDR);
	etb_writel(t, 0, ETBR_WRITEADDR);

	etb_lock(t);
}

static void sysrq_etm_dump(int key)
{
	dev_dbg(tracer.dev, "Dumping ETB buffer\n");
	etm_dump();
}

static struct sysrq_key_op sysrq_etm_op = {
	.handler = sysrq_etm_dump,
	.help_msg = "ETM buffer dump",
	.action_msg = "etm",
};

static int etb_open(struct inode *inode, struct file *file)
{
	if (!tracer.etb_regs)
		return -ENODEV;

	file->private_data = &tracer;

	return nonseekable_open(inode, file);
}

static ssize_t etb_read(struct file *file, char __user *data,
		size_t len, loff_t *ppos)
{
	int total, i;
	long length;
	struct tracectx *t = file->private_data;
	u32 first = 0;
	u32 *buf;

	mutex_lock(&t->mutex);

	if (trace_isrunning(t)) {
		length = 0;
		goto out;
	}

	etb_unlock(t);

	total = etb_getdatalen(t);
	if (total == t->etb_bufsz)
		first = etb_readl(t, ETBR_WRITEADDR);

	etb_writel(t, first, ETBR_READADDR);

	length = min(total * 4, (int)len);
	buf = vmalloc(length);

	dev_dbg(t->dev, "ETB buffer length: %d\n", total);
	dev_dbg(t->dev, "ETB status reg: %x\n", etb_readl(t, ETBR_STATUS));
	for (i = 0; i < length / 4; i++)
		buf[i] = etb_readl(t, ETBR_READMEM);

	/* the only way to deassert overflow bit in ETB status is this */
	etb_writel(t, 1, ETBR_CTRL);
	etb_writel(t, 0, ETBR_CTRL);

	etb_writel(t, 0, ETBR_WRITEADDR);
	etb_writel(t, 0, ETBR_READADDR);
	etb_writel(t, 0, ETBR_TRIGGERCOUNT);

	etb_lock(t);

	length -= copy_to_user(data, buf, length);
	vfree(buf);

out:
	mutex_unlock(&t->mutex);

	return length;
}

static int etb_release(struct inode *inode, struct file *file)
{
	/* there's nothing to do here, actually */
	return 0;
}

static const struct file_operations etb_fops = {
	.owner = THIS_MODULE,
	.read = etb_read,
	.open = etb_open,
	.release = etb_release,
	.llseek = no_llseek,
};

static struct miscdevice etb_miscdev = {
	.name = "tracebuf",
	.minor = 0,
	.fops = &etb_fops,
};

static int __devinit etb_probe(struct amba_device *dev, const struct amba_id *id)
{
	struct tracectx *t = &tracer;
	int ret = 0;

	ret = amba_request_regions(dev, NULL);
	if (ret)
		goto out;

	t->etb_regs = ioremap_nocache(dev->res.start, resource_size(&dev->res));
	if (!t->etb_regs) {
		ret = -ENOMEM;
		goto out_release;
	}

	amba_set_drvdata(dev, t);

	etb_miscdev.parent = &dev->dev;

	ret = misc_register(&etb_miscdev);
	if (ret)
		goto out_unmap;

	t->emu_clk = clk_get(&dev->dev, "emu_src_ck");
	if (IS_ERR(t->emu_clk)) {
		dev_dbg(&dev->dev, "Failed to obtain emu_src_ck.\n");
		return -EFAULT;
	}

	clk_enable(t->emu_clk);

	etb_unlock(t);
	t->etb_bufsz = etb_readl(t, ETBR_DEPTH);
	dev_dbg(&dev->dev, "Size: %x\n", t->etb_bufsz);

	/* make sure trace capture is disabled */
	etb_writel(t, 0, ETBR_CTRL);
	etb_writel(t, 0x1000, ETBR_FORMATTERCTRL);
	etb_lock(t);

	dev_dbg(&dev->dev, "ETB AMBA driver initialized.\n");

out:
	return ret;

out_unmap:
	amba_set_drvdata(dev, NULL);
	iounmap(t->etb_regs);

out_release:
	amba_release_regions(dev);

	return ret;
}

static int etb_remove(struct amba_device *dev)
{
	struct tracectx *t = amba_get_drvdata(dev);

	amba_set_drvdata(dev, NULL);

	iounmap(t->etb_regs);
	t->etb_regs = NULL;

	clk_disable(t->emu_clk);
	clk_put(t->emu_clk);

	amba_release_regions(dev);

	return 0;
}

static struct amba_id etb_ids[] = {
	{
		.id	= 0x0003b907,
		.mask	= 0x0007ffff,
	},
	{ 0, 0 },
};

static struct amba_driver etb_driver = {
	.drv		= {
		.name	= "etb",
		.owner	= THIS_MODULE,
	},
	.probe		= etb_probe,
	.remove		= etb_remove,
	.id_table	= etb_ids,
};

/* use a sysfs file "trace_running" to start/stop tracing */
static ssize_t trace_running_show(struct kobject *kobj,
				  struct kobj_attribute *attr,
				  char *buf)
{
	return sprintf(buf, "%x\n", trace_isrunning(&tracer));
}

static ssize_t trace_running_store(struct kobject *kobj,
				   struct kobj_attribute *attr,
				   const char *buf, size_t n)
{
	unsigned int value;
	int ret;

	if (sscanf(buf, "%u", &value) != 1)
		return -EINVAL;

	mutex_lock(&tracer.mutex);
	ret = value ? trace_start(&tracer) : trace_stop(&tracer);
	mutex_unlock(&tracer.mutex);

	return ret ? : n;
}

static struct kobj_attribute trace_running_attr =
	__ATTR(trace_running, 0644, trace_running_show, trace_running_store);

static ssize_t trace_info_show(struct kobject *kobj,
				  struct kobj_attribute *attr,
				  char *buf)
{
	u32 etb_wa, etb_ra, etb_st, etb_fc, etm_ctrl, etm_st;
	int datalen;

	etb_unlock(&tracer);
	datalen = etb_getdatalen(&tracer);
	etb_wa = etb_readl(&tracer, ETBR_WRITEADDR);
	etb_ra = etb_readl(&tracer, ETBR_READADDR);
	etb_st = etb_readl(&tracer, ETBR_STATUS);
	etb_fc = etb_readl(&tracer, ETBR_FORMATTERCTRL);
	etb_lock(&tracer);

	etm_unlock(&tracer);
	etm_ctrl = etm_readl(&tracer, ETMR_CTRL);
	etm_st = etm_readl(&tracer, ETMR_STATUS);
	etm_lock(&tracer);

	return sprintf(buf, "Trace buffer len: %d\nComparator pairs: %d\n"
			"ETBR_WRITEADDR:\t%08x\n"
			"ETBR_READADDR:\t%08x\n"
			"ETBR_STATUS:\t%08x\n"
			"ETBR_FORMATTERCTRL:\t%08x\n"
			"ETMR_CTRL:\t%08x\n"
			"ETMR_STATUS:\t%08x\n",
			datalen,
			tracer.ncmppairs,
			etb_wa,
			etb_ra,
			etb_st,
			etb_fc,
			etm_ctrl,
			etm_st
			);
}

static struct kobj_attribute trace_info_attr =
	__ATTR(trace_info, 0444, trace_info_show, NULL);

static ssize_t trace_mode_show(struct kobject *kobj,
				  struct kobj_attribute *attr,
				  char *buf)
{
	return sprintf(buf, "%d %d\n",
			!!(tracer.flags & TRACER_CYCLE_ACC),
			tracer.etm_portsz);
}

static ssize_t trace_mode_store(struct kobject *kobj,
				   struct kobj_attribute *attr,
				   const char *buf, size_t n)
{
	unsigned int cycacc, portsz;

	if (sscanf(buf, "%u %u", &cycacc, &portsz) != 2)
		return -EINVAL;

	mutex_lock(&tracer.mutex);
	if (cycacc)
		tracer.flags |= TRACER_CYCLE_ACC;
	else
		tracer.flags &= ~TRACER_CYCLE_ACC;

	tracer.etm_portsz = portsz & 0x0f;
	mutex_unlock(&tracer.mutex);

	return n;
}

static struct kobj_attribute trace_mode_attr =
	__ATTR(trace_mode, 0644, trace_mode_show, trace_mode_store);

static int __devinit etm_probe(struct amba_device *dev, const struct amba_id *id)
{
	struct tracectx *t = &tracer;
	int ret = 0;

	if (t->etm_regs) {
		dev_dbg(&dev->dev, "ETM already initialized\n");
		ret = -EBUSY;
		goto out;
	}

	ret = amba_request_regions(dev, NULL);
	if (ret)
		goto out;

	t->etm_regs = ioremap_nocache(dev->res.start, resource_size(&dev->res));
	if (!t->etm_regs) {
		ret = -ENOMEM;
		goto out_release;
	}

	amba_set_drvdata(dev, t);

	mutex_init(&t->mutex);
	t->dev = &dev->dev;
	t->flags = TRACER_CYCLE_ACC;
	t->etm_portsz = 1;

	etm_unlock(t);
	(void)etm_readl(t, ETMMR_PDSR);
	/* dummy first read */
	(void)etm_readl(&tracer, ETMMR_OSSRR);

	t->ncmppairs = etm_readl(t, ETMR_CONFCODE) & 0xf;
	etm_writel(t, 0x440, ETMR_CTRL);
	etm_lock(t);

	ret = sysfs_create_file(&dev->dev.kobj,
			&trace_running_attr.attr);
	if (ret)
		goto out_unmap;

	/* failing to create any of these two is not fatal */
	ret = sysfs_create_file(&dev->dev.kobj, &trace_info_attr.attr);
	if (ret)
		dev_dbg(&dev->dev, "Failed to create trace_info in sysfs\n");

	ret = sysfs_create_file(&dev->dev.kobj, &trace_mode_attr.attr);
	if (ret)
		dev_dbg(&dev->dev, "Failed to create trace_mode in sysfs\n");

	dev_dbg(t->dev, "ETM AMBA driver initialized.\n");

out:
	return ret;

out_unmap:
	amba_set_drvdata(dev, NULL);
	iounmap(t->etm_regs);

out_release:
	amba_release_regions(dev);

	return ret;
}

static int etm_remove(struct amba_device *dev)
{
	struct tracectx *t = amba_get_drvdata(dev);

	amba_set_drvdata(dev, NULL);

	iounmap(t->etm_regs);
	t->etm_regs = NULL;

	amba_release_regions(dev);

	sysfs_remove_file(&dev->dev.kobj, &trace_running_attr.attr);
	sysfs_remove_file(&dev->dev.kobj, &trace_info_attr.attr);
	sysfs_remove_file(&dev->dev.kobj, &trace_mode_attr.attr);

	return 0;
}

static struct amba_id etm_ids[] = {
	{
		.id	= 0x0003b921,
		.mask	= 0x0007ffff,
	},
	{ 0, 0 },
};

static struct amba_driver etm_driver = {
	.drv		= {
		.name   = "etm",
		.owner  = THIS_MODULE,
	},
	.probe		= etm_probe,
	.remove		= etm_remove,
	.id_table	= etm_ids,
};

static int __init etm_init(void)
{
	int retval;

	retval = amba_driver_register(&etb_driver);
	if (retval) {
		printk(KERN_ERR "Failed to register etb\n");
		return retval;
	}

	retval = amba_driver_register(&etm_driver);
	if (retval) {
		amba_driver_unregister(&etb_driver);
		printk(KERN_ERR "Failed to probe etm\n");
		return retval;
	}

	/* not being able to install this handler is not fatal */
	(void)register_sysrq_key('v', &sysrq_etm_op);

	return 0;
}

device_initcall(etm_init);
Commit	Line	Data
c5d6c770 AS	1	/*
	2	* linux/arch/arm/kernel/etm.c
	3	*
	4	* Driver for ARM's Embedded Trace Macrocell and Embedded Trace Buffer.
	5	*
	6	* Copyright (C) 2009 Nokia Corporation.
	7	* Alexander Shishkin
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License version 2 as
	11	* published by the Free Software Foundation.
	12	*/
	13
	14	#include <linux/kernel.h>
	15	#include <linux/init.h>
	16	#include <linux/types.h>
	17	#include <linux/io.h>
	18	#include <linux/sysrq.h>
	19	#include <linux/device.h>
	20	#include <linux/clk.h>
	21	#include <linux/amba/bus.h>
	22	#include <linux/fs.h>
	23	#include <linux/uaccess.h>
	24	#include <linux/miscdevice.h>
	25	#include <linux/vmalloc.h>
	26	#include <linux/mutex.h>
	27	#include <asm/hardware/coresight.h>
	28	#include <asm/sections.h>
	29
	30	MODULE_LICENSE("GPL");
	31	MODULE_AUTHOR("Alexander Shishkin");
	32
8234eaef AS	33	/*
	34	* ETM tracer state
	35	*/
	36	struct tracectx {
	37	unsigned int etb_bufsz;
	38	void __iomem *etb_regs;
	39	void __iomem *etm_regs;
	40	unsigned long flags;
	41	int ncmppairs;
	42	int etm_portsz;
	43	struct device *dev;
	44	struct clk *emu_clk;
	45	struct mutex mutex;
	46	};
	47
c5d6c770 AS	48	static struct tracectx tracer;
	49
	50	static inline bool trace_isrunning(struct tracectx *t)
	51	{
	52	return !!(t->flags & TRACER_RUNNING);
	53	}
	54
	55	static int etm_setup_address_range(struct tracectx *t, int n,
	56	unsigned long start, unsigned long end, int exclude, int data)
	57	{
	58	u32 flags = ETMAAT_ARM \| ETMAAT_IGNCONTEXTID \| ETMAAT_NSONLY \| \
	59	ETMAAT_NOVALCMP;
	60
	61	if (n < 1 \|\| n > t->ncmppairs)
	62	return -EINVAL;
	63
	64	/* comparators and ranges are numbered starting with 1 as opposed
	65	* to bits in a word */
	66	n--;
	67
	68	if (data)
	69	flags \|= ETMAAT_DLOADSTORE;
	70	else
	71	flags \|= ETMAAT_IEXEC;
	72
	73	/* first comparator for the range */
	74	etm_writel(t, flags, ETMR_COMP_ACC_TYPE(n * 2));
	75	etm_writel(t, start, ETMR_COMP_VAL(n * 2));
	76
	77	/* second comparator is right next to it */
	78	etm_writel(t, flags, ETMR_COMP_ACC_TYPE(n * 2 + 1));
	79	etm_writel(t, end, ETMR_COMP_VAL(n * 2 + 1));
	80
	81	flags = exclude ? ETMTE_INCLEXCL : 0;
	82	etm_writel(t, flags \| (1 << n), ETMR_TRACEENCTRL);
	83
	84	return 0;
	85	}
	86
	87	static int trace_start(struct tracectx *t)
	88	{
	89	u32 v;
	90	unsigned long timeout = TRACER_TIMEOUT;
	91
	92	etb_unlock(t);
	93
	94	etb_writel(t, 0, ETBR_FORMATTERCTRL);
	95	etb_writel(t, 1, ETBR_CTRL);
	96
	97	etb_lock(t);
	98
	99	/* configure etm */
	100	v = ETMCTRL_OPTS \| ETMCTRL_PROGRAM \| ETMCTRL_PORTSIZE(t->etm_portsz);
	101
	102	if (t->flags & TRACER_CYCLE_ACC)
	103	v \|= ETMCTRL_CYCLEACCURATE;
	104
	105	etm_unlock(t);
	106
	107	etm_writel(t, v, ETMR_CTRL);
	108
	109	while (!(etm_readl(t, ETMR_CTRL) & ETMCTRL_PROGRAM) && --timeout)
	110	;
	111	if (!timeout) {
112	dev_dbg(t->dev, "Waiting for progbit to assert timed out\n");
113	etm_lock(t);
114	return -EFAULT;
115	}
116
117	etm_setup_address_range(t, 1, (unsigned long)_stext,
118	(unsigned long)_etext, 0, 0);
119	etm_writel(t, 0, ETMR_TRACEENCTRL2);
120	etm_writel(t, 0, ETMR_TRACESSCTRL);
121	etm_writel(t, 0x6f, ETMR_TRACEENEVT);
122
123	v &= ~ETMCTRL_PROGRAM;
124	v \|= ETMCTRL_PORTSEL;
125
126	etm_writel(t, v, ETMR_CTRL);
127
128	timeout = TRACER_TIMEOUT;
129	while (etm_readl(t, ETMR_CTRL) & ETMCTRL_PROGRAM && --timeout)
130	;
131	if (!timeout) {
132	dev_dbg(t->dev, "Waiting for progbit to deassert timed out\n");
133	etm_lock(t);
134	return -EFAULT;
135	}
136
137	etm_lock(t);
138
139	t->flags \|= TRACER_RUNNING;
140
141	return 0;
142	}
143
144	static int trace_stop(struct tracectx *t)
145	{
146	unsigned long timeout = TRACER_TIMEOUT;
147
148	etm_unlock(t);
149
150	etm_writel(t, 0x440, ETMR_CTRL);
151	while (!(etm_readl(t, ETMR_CTRL) & ETMCTRL_PROGRAM) && --timeout)
152	;
153	if (!timeout) {
154	dev_dbg(t->dev, "Waiting for progbit to assert timed out\n");
155	etm_lock(t);
156	return -EFAULT;
157	}
158
159	etm_lock(t);
160
161	etb_unlock(t);
162	etb_writel(t, ETBFF_MANUAL_FLUSH, ETBR_FORMATTERCTRL);
163
164	timeout = TRACER_TIMEOUT;
165	while (etb_readl(t, ETBR_FORMATTERCTRL) &
166	ETBFF_MANUAL_FLUSH && --timeout)
167	;
168	if (!timeout) {
169	dev_dbg(t->dev, "Waiting for formatter flush to commence "
170	"timed out\n");
171	etb_lock(t);
172	return -EFAULT;
173	}
174
175	etb_writel(t, 0, ETBR_CTRL);
176
177	etb_lock(t);
178
179	t->flags &= ~TRACER_RUNNING;
180
181	return 0;
182	}
183
184	static int etb_getdatalen(struct tracectx *t)
185	{
186	u32 v;
187	int rp, wp;
188
189	v = etb_readl(t, ETBR_STATUS);
190
191	if (v & 1)
192	return t->etb_bufsz;
193
194	rp = etb_readl(t, ETBR_READADDR);
195	wp = etb_readl(t, ETBR_WRITEADDR);
196
197	if (rp > wp) {
198	etb_writel(t, 0, ETBR_READADDR);
199	etb_writel(t, 0, ETBR_WRITEADDR);
200
201	return 0;
202	}
203
204	return wp - rp;
205	}
206
207	/* sysrq+v will always stop the running trace and leave it at that */
208	static void etm_dump(void)
209	{
210	struct tracectx *t = &tracer;
211	u32 first = 0;
212	int length;
213
214	if (!t->etb_regs) {
215	printk(KERN_INFO "No tracing hardware found\n");
216	return;
217	}
218
219	if (trace_isrunning(t))
220	trace_stop(t);
221
222	etb_unlock(t);
223
224	length = etb_getdatalen(t);
225
226	if (length == t->etb_bufsz)
227	first = etb_readl(t, ETBR_WRITEADDR);
228
229	etb_writel(t, first, ETBR_READADDR);
230
231	printk(KERN_INFO "Trace buffer contents length: %d\n", length);
232	printk(KERN_INFO "--- ETB buffer begin ---\n");
233	for (; length; length--)
234	printk("%08x", cpu_to_be32(etb_readl(t, ETBR_READMEM)));
235	printk(KERN_INFO "\n--- ETB buffer end ---\n");
236
237	/* deassert the overflow bit */
238	etb_writel(t, 1, ETBR_CTRL);
239	etb_writel(t, 0, ETBR_CTRL);
240
241	etb_writel(t, 0, ETBR_TRIGGERCOUNT);
242	etb_writel(t, 0, ETBR_READADDR);
243	etb_writel(t, 0, ETBR_WRITEADDR);
244
245	etb_lock(t);
246	}
247
1495cc9d	248	static void sysrq_etm_dump(int key)
c5d6c770 AS	249	{
	250	dev_dbg(tracer.dev, "Dumping ETB buffer\n");
	251	etm_dump();
	252	}
	253
	254	static struct sysrq_key_op sysrq_etm_op = {
	255	.handler = sysrq_etm_dump,
	256	.help_msg = "ETM buffer dump",
	257	.action_msg = "etm",
	258	};
	259
	260	static int etb_open(struct inode inode, struct file file)
	261	{
	262	if (!tracer.etb_regs)
	263	return -ENODEV;
	264
	265	file->private_data = &tracer;
	266
	267	return nonseekable_open(inode, file);
	268	}
	269
	270	static ssize_t etb_read(struct file file, char __user data,
	271	size_t len, loff_t *ppos)
	272	{
	273	int total, i;
	274	long length;
	275	struct tracectx *t = file->private_data;
	276	u32 first = 0;
	277	u32 *buf;
	278
	279	mutex_lock(&t->mutex);
	280
	281	if (trace_isrunning(t)) {
	282	length = 0;
	283	goto out;
	284	}
	285
	286	etb_unlock(t);
	287
	288	total = etb_getdatalen(t);
	289	if (total == t->etb_bufsz)
	290	first = etb_readl(t, ETBR_WRITEADDR);
	291
	292	etb_writel(t, first, ETBR_READADDR);
	293
	294	length = min(total * 4, (int)len);
	295	buf = vmalloc(length);
	296
	297	dev_dbg(t->dev, "ETB buffer length: %d\n", total);
	298	dev_dbg(t->dev, "ETB status reg: %x\n", etb_readl(t, ETBR_STATUS));
	299	for (i = 0; i < length / 4; i++)
	300	buf[i] = etb_readl(t, ETBR_READMEM);
	301
	302	/* the only way to deassert overflow bit in ETB status is this */
	303	etb_writel(t, 1, ETBR_CTRL);
	304	etb_writel(t, 0, ETBR_CTRL);
	305
	306	etb_writel(t, 0, ETBR_WRITEADDR);
	307	etb_writel(t, 0, ETBR_READADDR);
	308	etb_writel(t, 0, ETBR_TRIGGERCOUNT);
	309
	310	etb_lock(t);
	311
	312	length -= copy_to_user(data, buf, length);
313	vfree(buf);
314
315	out:
316	mutex_unlock(&t->mutex);
317
318	return length;
319	}
320
321	static int etb_release(struct inode inode, struct file file)
322	{
323	/* there's nothing to do here, actually */
324	return 0;
325	}
326
327	static const struct file_operations etb_fops = {
328	.owner = THIS_MODULE,
329	.read = etb_read,
330	.open = etb_open,
331	.release = etb_release,
6038f373	332	.llseek = no_llseek,
c5d6c770 AS	333	};
	334
	335	static struct miscdevice etb_miscdev = {
	336	.name = "tracebuf",
	337	.minor = 0,
	338	.fops = &etb_fops,
	339	};
	340
8e880699	341	static int __devinit etb_probe(struct amba_device dev, const struct amba_id id)
c5d6c770 AS	342	{
	343	struct tracectx *t = &tracer;
	344	int ret = 0;
	345
	346	ret = amba_request_regions(dev, NULL);
	347	if (ret)
	348	goto out;
	349
	350	t->etb_regs = ioremap_nocache(dev->res.start, resource_size(&dev->res));
	351	if (!t->etb_regs) {
	352	ret = -ENOMEM;
	353	goto out_release;
	354	}
	355
	356	amba_set_drvdata(dev, t);
	357
	358	etb_miscdev.parent = &dev->dev;
	359
	360	ret = misc_register(&etb_miscdev);
	361	if (ret)
	362	goto out_unmap;
	363
	364	t->emu_clk = clk_get(&dev->dev, "emu_src_ck");
	365	if (IS_ERR(t->emu_clk)) {
	366	dev_dbg(&dev->dev, "Failed to obtain emu_src_ck.\n");
	367	return -EFAULT;
	368	}
	369
	370	clk_enable(t->emu_clk);
	371
	372	etb_unlock(t);
	373	t->etb_bufsz = etb_readl(t, ETBR_DEPTH);
	374	dev_dbg(&dev->dev, "Size: %x\n", t->etb_bufsz);
	375
	376	/* make sure trace capture is disabled */
	377	etb_writel(t, 0, ETBR_CTRL);
	378	etb_writel(t, 0x1000, ETBR_FORMATTERCTRL);
	379	etb_lock(t);
	380
	381	dev_dbg(&dev->dev, "ETB AMBA driver initialized.\n");
	382
	383	out:
	384	return ret;
	385
	386	out_unmap:
	387	amba_set_drvdata(dev, NULL);
	388	iounmap(t->etb_regs);
	389
	390	out_release:
	391	amba_release_regions(dev);
	392
	393	return ret;
	394	}
	395
	396	static int etb_remove(struct amba_device *dev)
	397	{
	398	struct tracectx *t = amba_get_drvdata(dev);
	399
	400	amba_set_drvdata(dev, NULL);
	401
	402	iounmap(t->etb_regs);
	403	t->etb_regs = NULL;
	404
	405	clk_disable(t->emu_clk);
406	clk_put(t->emu_clk);
407
408	amba_release_regions(dev);
409
410	return 0;
411	}
412
413	static struct amba_id etb_ids[] = {
414	{
415	.id = 0x0003b907,
416	.mask = 0x0007ffff,
417	},
418	{ 0, 0 },
419	};
420
421	static struct amba_driver etb_driver = {
422	.drv = {
423	.name = "etb",
424	.owner = THIS_MODULE,
425	},
426	.probe = etb_probe,
427	.remove = etb_remove,
428	.id_table = etb_ids,
429	};
430
431	/* use a sysfs file "trace_running" to start/stop tracing */
432	static ssize_t trace_running_show(struct kobject *kobj,
433	struct kobj_attribute *attr,
434	char *buf)
435	{
436	return sprintf(buf, "%x\n", trace_isrunning(&tracer));
437	}
438
439	static ssize_t trace_running_store(struct kobject *kobj,
440	struct kobj_attribute *attr,
441	const char *buf, size_t n)
442	{
443	unsigned int value;
444	int ret;
445
446	if (sscanf(buf, "%u", &value) != 1)
447	return -EINVAL;
448
449	mutex_lock(&tracer.mutex);
450	ret = value ? trace_start(&tracer) : trace_stop(&tracer);
451	mutex_unlock(&tracer.mutex);
452
453	return ret ? : n;
454	}
455
456	static struct kobj_attribute trace_running_attr =
457	__ATTR(trace_running, 0644, trace_running_show, trace_running_store);
458
459	static ssize_t trace_info_show(struct kobject *kobj,
460	struct kobj_attribute *attr,
461	char *buf)
462	{
463	u32 etb_wa, etb_ra, etb_st, etb_fc, etm_ctrl, etm_st;
464	int datalen;
465
466	etb_unlock(&tracer);
467	datalen = etb_getdatalen(&tracer);
468	etb_wa = etb_readl(&tracer, ETBR_WRITEADDR);
469	etb_ra = etb_readl(&tracer, ETBR_READADDR);
470	etb_st = etb_readl(&tracer, ETBR_STATUS);
471	etb_fc = etb_readl(&tracer, ETBR_FORMATTERCTRL);
472	etb_lock(&tracer);
473
474	etm_unlock(&tracer);
475	etm_ctrl = etm_readl(&tracer, ETMR_CTRL);
476	etm_st = etm_readl(&tracer, ETMR_STATUS);
477	etm_lock(&tracer);
478
479	return sprintf(buf, "Trace buffer len: %d\nComparator pairs: %d\n"
480	"ETBR_WRITEADDR:\t%08x\n"
481	"ETBR_READADDR:\t%08x\n"
482	"ETBR_STATUS:\t%08x\n"
483	"ETBR_FORMATTERCTRL:\t%08x\n"
484	"ETMR_CTRL:\t%08x\n"
485	"ETMR_STATUS:\t%08x\n",
486	datalen,
487	tracer.ncmppairs,
488	etb_wa,
489	etb_ra,
490	etb_st,
491	etb_fc,
492	etm_ctrl,
493	etm_st
494	);
495	}
496
497	static struct kobj_attribute trace_info_attr =
498	__ATTR(trace_info, 0444, trace_info_show, NULL);
499
500	static ssize_t trace_mode_show(struct kobject *kobj,
501	struct kobj_attribute *attr,
502	char *buf)
503	{
504	return sprintf(buf, "%d %d\n",
505	!!(tracer.flags & TRACER_CYCLE_ACC),
506	tracer.etm_portsz);
507	}
508
509	static ssize_t trace_mode_store(struct kobject *kobj,
510	struct kobj_attribute *attr,
511	const char *buf, size_t n)
512	{
513	unsigned int cycacc, portsz;
514
515	if (sscanf(buf, "%u %u", &cycacc, &portsz) != 2)
516	return -EINVAL;
517
518	mutex_lock(&tracer.mutex);
519	if (cycacc)
520	tracer.flags \|= TRACER_CYCLE_ACC;
521	else
522	tracer.flags &= ~TRACER_CYCLE_ACC;
523
524	tracer.etm_portsz = portsz & 0x0f;
525	mutex_unlock(&tracer.mutex);
526
527	return n;
528	}
529
530	static struct kobj_attribute trace_mode_attr =
531	__ATTR(trace_mode, 0644, trace_mode_show, trace_mode_store);
532
8e880699	533	static int __devinit etm_probe(struct amba_device dev, const struct amba_id id)
c5d6c770 AS	534	{
	535	struct tracectx *t = &tracer;
	536	int ret = 0;
	537
	538	if (t->etm_regs) {
	539	dev_dbg(&dev->dev, "ETM already initialized\n");
	540	ret = -EBUSY;
	541	goto out;
	542	}
	543
	544	ret = amba_request_regions(dev, NULL);
	545	if (ret)
	546	goto out;
	547
	548	t->etm_regs = ioremap_nocache(dev->res.start, resource_size(&dev->res));
	549	if (!t->etm_regs) {
	550	ret = -ENOMEM;
	551	goto out_release;
	552	}
	553
	554	amba_set_drvdata(dev, t);
	555
	556	mutex_init(&t->mutex);
	557	t->dev = &dev->dev;
	558	t->flags = TRACER_CYCLE_ACC;
	559	t->etm_portsz = 1;
	560
	561	etm_unlock(t);
988257cf AS	562	(void)etm_readl(t, ETMMR_PDSR);
	563	/* dummy first read */
	564	(void)etm_readl(&tracer, ETMMR_OSSRR);
c5d6c770 AS	565
	566	t->ncmppairs = etm_readl(t, ETMR_CONFCODE) & 0xf;
	567	etm_writel(t, 0x440, ETMR_CTRL);
	568	etm_lock(t);
	569
	570	ret = sysfs_create_file(&dev->dev.kobj,
	571	&trace_running_attr.attr);
	572	if (ret)
	573	goto out_unmap;
	574
	575	/* failing to create any of these two is not fatal */
	576	ret = sysfs_create_file(&dev->dev.kobj, &trace_info_attr.attr);
	577	if (ret)
	578	dev_dbg(&dev->dev, "Failed to create trace_info in sysfs\n");
	579
	580	ret = sysfs_create_file(&dev->dev.kobj, &trace_mode_attr.attr);
	581	if (ret)
	582	dev_dbg(&dev->dev, "Failed to create trace_mode in sysfs\n");
	583
	584	dev_dbg(t->dev, "ETM AMBA driver initialized.\n");
	585
	586	out:
	587	return ret;
	588
	589	out_unmap:
	590	amba_set_drvdata(dev, NULL);
	591	iounmap(t->etm_regs);
	592
	593	out_release:
	594	amba_release_regions(dev);
	595
	596	return ret;
	597	}
	598
	599	static int etm_remove(struct amba_device *dev)
	600	{
	601	struct tracectx *t = amba_get_drvdata(dev);
	602
	603	amba_set_drvdata(dev, NULL);
	604
	605	iounmap(t->etm_regs);
	606	t->etm_regs = NULL;
	607
	608	amba_release_regions(dev);
	609
	610	sysfs_remove_file(&dev->dev.kobj, &trace_running_attr.attr);
	611	sysfs_remove_file(&dev->dev.kobj, &trace_info_attr.attr);
	612	sysfs_remove_file(&dev->dev.kobj, &trace_mode_attr.attr);
	613
	614	return 0;
	615	}
	616
	617	static struct amba_id etm_ids[] = {
	618	{
	619	.id = 0x0003b921,
	620	.mask = 0x0007ffff,
	621	},
	622	{ 0, 0 },
	623	};
	624
	625	static struct amba_driver etm_driver = {
	626	.drv = {
	627	.name = "etm",
	628	.owner = THIS_MODULE,
629	},
630	.probe = etm_probe,
631	.remove = etm_remove,
632	.id_table = etm_ids,
633	};
634
635	static int __init etm_init(void)
636	{
637	int retval;
638
639	retval = amba_driver_register(&etb_driver);
640	if (retval) {
641	printk(KERN_ERR "Failed to register etb\n");
642	return retval;
643	}
644
645	retval = amba_driver_register(&etm_driver);
646	if (retval) {
647	amba_driver_unregister(&etb_driver);
648	printk(KERN_ERR "Failed to probe etm\n");
649	return retval;
650	}
651
652	/* not being able to install this handler is not fatal */
653	(void)register_sysrq_key('v', &sysrq_etm_op);
654
655	return 0;
656	}
657
658	device_initcall(etm_init);
659