- 根目录:
- 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/slab.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 <linux/module.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;
int etm_regs_count;
unsigned long flags;
int ncmppairs;
int etm_portsz;
u32 etb_fc;
unsigned long range_start;
unsigned long range_end;
unsigned long data_range_start;
unsigned long data_range_end;
bool dump_initial_etb;
struct device *dev;
struct clk *emu_clk;
struct mutex mutex;
};
static struct tracectx tracer = {
.range_start = (unsigned long)_stext,
.range_end = (unsigned long)_etext,
};
static inline bool trace_isrunning(struct tracectx *t)
{
return !!(t->flags & TRACER_RUNNING);
}
static int etm_setup_address_range(struct tracectx *t, int id, int n,
unsigned long start, unsigned long end, int exclude, int data)
{
u32 flags = ETMAAT_ARM | ETMAAT_IGNCONTEXTID | ETMAAT_IGNSECURITY |
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, id, flags, ETMR_COMP_ACC_TYPE(n * 2));
etm_writel(t, id, start, ETMR_COMP_VAL(n * 2));
/* second comparator is right next to it */
etm_writel(t, id, flags, ETMR_COMP_ACC_TYPE(n * 2 + 1));
etm_writel(t, id, end, ETMR_COMP_VAL(n * 2 + 1));
if (data) {
flags = exclude ? ETMVDC3_EXCLONLY : 0;
if (exclude)
n += 8;
etm_writel(t, id, flags | BIT(n), ETMR_VIEWDATACTRL3);
} else {
flags = exclude ? ETMTE_INCLEXCL : 0;
etm_writel(t, id, flags | (1 << n), ETMR_TRACEENCTRL);
}
return 0;
}
static int trace_start_etm(struct tracectx *t, int id)
{
u32 v;
unsigned long timeout = TRACER_TIMEOUT;
v = ETMCTRL_OPTS | ETMCTRL_PROGRAM | ETMCTRL_PORTSIZE(t->etm_portsz);
if (t->flags & TRACER_CYCLE_ACC)
v |= ETMCTRL_CYCLEACCURATE;
if (t->flags & TRACER_TRACE_DATA)
v |= ETMCTRL_DATA_DO_ADDR;
etm_unlock(t, id);
etm_writel(t, id, v, ETMR_CTRL);
while (!(etm_readl(t, id, ETMR_CTRL) & ETMCTRL_PROGRAM) && --timeout)
;
if (!timeout) {
dev_dbg(t->dev, "Waiting for progbit to assert timed out\n");
etm_lock(t, id);
return -EFAULT;
}
if (t->range_start || t->range_end)
etm_setup_address_range(t, id, 1,
t->range_start, t->range_end, 0, 0);
else
etm_writel(t, id, ETMTE_INCLEXCL, ETMR_TRACEENCTRL);
etm_writel(t, id, 0, ETMR_TRACEENCTRL2);
etm_writel(t, id, 0, ETMR_TRACESSCTRL);
etm_writel(t, id, 0x6f, ETMR_TRACEENEVT);
etm_writel(t, id, 0, ETMR_VIEWDATACTRL1);
etm_writel(t, id, 0, ETMR_VIEWDATACTRL2);
if (t->data_range_start || t->data_range_end)
etm_setup_address_range(t, id, 2, t->data_range_start,
t->data_range_end, 0, 1);
else
etm_writel(t, id, ETMVDC3_EXCLONLY, ETMR_VIEWDATACTRL3);
etm_writel(t, id, 0x6f, ETMR_VIEWDATAEVT);
v &= ~ETMCTRL_PROGRAM;
v |= ETMCTRL_PORTSEL;
etm_writel(t, id, v, ETMR_CTRL);
timeout = TRACER_TIMEOUT;
while (etm_readl(t, id, ETMR_CTRL) & ETMCTRL_PROGRAM && --timeout)
;
if (!timeout) {
dev_dbg(t->dev, "Waiting for progbit to deassert timed out\n");
etm_lock(t, id);
return -EFAULT;
}
etm_lock(t, id);
return 0;
}
static int trace_start(struct tracectx *t)
{
int ret;
int id;
u32 etb_fc = t->etb_fc;
etb_unlock(t);
t->dump_initial_etb = false;
etb_writel(t, 0, ETBR_WRITEADDR);
etb_writel(t, etb_fc, ETBR_FORMATTERCTRL);
etb_writel(t, 1, ETBR_CTRL);
etb_lock(t);
/* configure etm(s) */
for (id = 0; id < t->etm_regs_count; id++) {
ret = trace_start_etm(t, id);
if (ret)
return ret;
}
t->flags |= TRACER_RUNNING;
return 0;
}
static int trace_stop_etm(struct tracectx *t, int id)
{
unsigned long timeout = TRACER_TIMEOUT;
etm_unlock(t, id);
etm_writel(t, id, 0x441, ETMR_CTRL);
while (!(etm_readl(t, id, ETMR_CTRL) & ETMCTRL_PROGRAM) && --timeout)
;
if (!timeout) {
dev_dbg(t->dev, "Waiting for progbit to assert timed out\n");
etm_lock(t, id);
return -EFAULT;
}
etm_lock(t, id);
return 0;
}
static int trace_stop(struct tracectx *t)
{
int id;
int ret;
unsigned long timeout = TRACER_TIMEOUT;
u32 etb_fc = t->etb_fc;
for (id = 0; id < t->etm_regs_count; id++) {
ret = trace_stop_etm(t, id);
if (ret)
return ret;
}
etb_unlock(t);
if (etb_fc) {
etb_fc |= ETBFF_STOPFL;
etb_writel(t, t->etb_fc, ETBR_FORMATTERCTRL);
}
etb_writel(t, etb_fc | 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 wp;
v = etb_readl(t, ETBR_STATUS);
if (v & 1)
return t->etb_bufsz;
wp = etb_readl(t, ETBR_WRITEADDR);
return wp;
}
/* 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");
etb_lock(t);
}
static void sysrq_etm_dump(int key)
{
if (!mutex_trylock(&tracer.mutex)) {
printk(KERN_INFO "Tracing hardware busy\n");
return;
}
dev_dbg(tracer.dev, "Dumping ETB buffer\n");
etm_dump();
mutex_unlock(&tracer.mutex);
}
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;
int wpos;
int skip;
long wlength;
loff_t pos = *ppos;
mutex_lock(&t->mutex);
if (trace_isrunning(t)) {
length = 0;
goto out;
}
etb_unlock(t);
total = etb_getdatalen(t);
if (total == 0 && t->dump_initial_etb)
total = t->etb_bufsz;
if (total == t->etb_bufsz)
first = etb_readl(t, ETBR_WRITEADDR);
if (pos > total * 4) {
skip = 0;
wpos = total;
} else {
skip = (int)pos % 4;
wpos = (int)pos / 4;
}
total -= wpos;
first = (first + wpos) % t->etb_bufsz;
etb_writel(t, first, ETBR_READADDR);
wlength = min(total, DIV_ROUND_UP(skip + (int)len, 4));
length = min(total * 4 - skip, (int)len);
buf = vmalloc(wlength * 4);
dev_dbg(t->dev, "ETB read %ld bytes to %lld from %ld words at %d\n",
length, pos, wlength, first);
dev_dbg(t->dev, "ETB buffer length: %d\n", total + wpos);
dev_dbg(t->dev, "ETB status reg: %x\n", etb_readl(t, ETBR_STATUS));
for (i = 0; i < wlength; i++)
buf[i] = etb_readl(t, ETBR_READMEM);
etb_lock(t);
length -= copy_to_user(data, (u8 *)buf + skip, length);
vfree(buf);
*ppos = pos + length;
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;
mutex_lock(&t->mutex);
t->etb_regs = ioremap_nocache(dev->res.start, resource_size(&dev->res));
if (!t->etb_regs) {
ret = -ENOMEM;
goto out_release;
}
t->dev = &dev->dev;
t->dump_initial_etb = true;
amba_set_drvdata(dev, t);
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);
mutex_unlock(&t->mutex);
etb_miscdev.parent = &dev->dev;
ret = misc_register(&etb_miscdev);
if (ret)
goto out_unmap;
/* Get optional clock. Currently used to select clock source on omap3 */
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");
else
clk_enable(t->emu_clk);
dev_dbg(&dev->dev, "ETB AMBA driver initialized.\n");
out:
return ret;
out_unmap:
mutex_lock(&t->mutex);
amba_set_drvdata(dev, NULL);
iounmap(t->etb_regs);
t->etb_regs = NULL;
out_release:
mutex_unlock(&t->mutex);
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;
if (!IS_ERR(t->emu_clk)) {
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);
if (!tracer.etb_regs)
ret = -ENODEV;
else
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;
int id;
int ret;
mutex_lock(&tracer.mutex);
if (tracer.etb_regs) {
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);
} else {
etb_wa = etb_ra = etb_st = etb_fc = ~0;
datalen = -1;
}
ret = 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",
datalen,
tracer.ncmppairs,
etb_wa,
etb_ra,
etb_st,
etb_fc
);
for (id = 0; id < tracer.etm_regs_count; id++) {
etm_unlock(&tracer, id);
etm_ctrl = etm_readl(&tracer, id, ETMR_CTRL);
etm_st = etm_readl(&tracer, id, ETMR_STATUS);
etm_lock(&tracer, id);
ret += sprintf(buf + ret, "ETMR_CTRL:\t%08x\n"
"ETMR_STATUS:\t%08x\n",
etm_ctrl,
etm_st
);
}
mutex_unlock(&tracer.mutex);
return ret;
}
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 ssize_t trace_range_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
return sprintf(buf, "%08lx %08lx\n",
tracer.range_start, tracer.range_end);
}
static ssize_t trace_range_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t n)
{
unsigned long range_start, range_end;
if (sscanf(buf, "%lx %lx", &range_start, &range_end) != 2)
return -EINVAL;
mutex_lock(&tracer.mutex);
tracer.range_start = range_start;
tracer.range_end = range_end;
mutex_unlock(&tracer.mutex);
return n;
}
static struct kobj_attribute trace_range_attr =
__ATTR(trace_range, 0644, trace_range_show, trace_range_store);
static ssize_t trace_data_range_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
unsigned long range_start;
u64 range_end;
mutex_lock(&tracer.mutex);
range_start = tracer.data_range_start;
range_end = tracer.data_range_end;
if (!range_end && (tracer.flags & TRACER_TRACE_DATA))
range_end = 0x100000000ULL;
mutex_unlock(&tracer.mutex);
return sprintf(buf, "%08lx %08llx\n", range_start, range_end);
}
static ssize_t trace_data_range_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t n)
{
unsigned long range_start;
u64 range_end;
if (sscanf(buf, "%lx %llx", &range_start, &range_end) != 2)
return -EINVAL;
mutex_lock(&tracer.mutex);
tracer.data_range_start = range_start;
tracer.data_range_end = (unsigned long)range_end;
if (range_end)
tracer.flags |= TRACER_TRACE_DATA;
else
tracer.flags &= ~TRACER_TRACE_DATA;
mutex_unlock(&tracer.mutex);
return n;
}
static struct kobj_attribute trace_data_range_attr =
__ATTR(trace_data_range, 0644,
trace_data_range_show, trace_data_range_store);
static int __devinit etm_probe(struct amba_device *dev, const struct amba_id *id)
{
struct tracectx *t = &tracer;
int ret = 0;
void __iomem **new_regs;
int new_count;
mutex_lock(&t->mutex);
new_count = t->etm_regs_count + 1;
new_regs = krealloc(t->etm_regs,
sizeof(t->etm_regs[0]) * new_count, GFP_KERNEL);
if (!new_regs) {
dev_dbg(&dev->dev, "Failed to allocate ETM register array\n");
ret = -ENOMEM;
goto out;
}
t->etm_regs = new_regs;
ret = amba_request_regions(dev, NULL);
if (ret)
goto out;
t->etm_regs[t->etm_regs_count] =
ioremap_nocache(dev->res.start, resource_size(&dev->res));
if (!t->etm_regs[t->etm_regs_count]) {
ret = -ENOMEM;
goto out_release;
}
amba_set_drvdata(dev, t->etm_regs[t->etm_regs_count]);
t->flags = TRACER_CYCLE_ACC | TRACER_TRACE_DATA;
t->etm_portsz = 1;
etm_unlock(t, t->etm_regs_count);
(void)etm_readl(t, t->etm_regs_count, ETMMR_PDSR);
/* dummy first read */
(void)etm_readl(&tracer, t->etm_regs_count, ETMMR_OSSRR);
t->ncmppairs = etm_readl(t, t->etm_regs_count, ETMR_CONFCODE) & 0xf;
etm_writel(t, t->etm_regs_count, 0x441, ETMR_CTRL);
etm_writel(t, t->etm_regs_count, new_count, ETMR_TRACEIDR);
etm_lock(t, t->etm_regs_count);
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");
ret = sysfs_create_file(&dev->dev.kobj, &trace_range_attr.attr);
if (ret)
dev_dbg(&dev->dev, "Failed to create trace_range in sysfs\n");
ret = sysfs_create_file(&dev->dev.kobj, &trace_data_range_attr.attr);
if (ret)
dev_dbg(&dev->dev,
"Failed to create trace_data_range in sysfs\n");
dev_dbg(&dev->dev, "ETM AMBA driver initialized.\n");
/* Enable formatter if there are multiple trace sources */
if (new_count > 1)
t->etb_fc = ETBFF_ENFCONT | ETBFF_ENFTC;
t->etm_regs_count = new_count;
out:
mutex_unlock(&t->mutex);
return ret;
out_unmap:
amba_set_drvdata(dev, NULL);
iounmap(t->etm_regs[t->etm_regs_count]);
out_release:
amba_release_regions(dev);
mutex_unlock(&t->mutex);
return ret;
}
static int etm_remove(struct amba_device *dev)
{
int i;
struct tracectx *t = &tracer;
void __iomem *etm_regs = amba_get_drvdata(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);
sysfs_remove_file(&dev->dev.kobj, &trace_range_attr.attr);
sysfs_remove_file(&dev->dev.kobj, &trace_data_range_attr.attr);
amba_set_drvdata(dev, NULL);
mutex_lock(&t->mutex);
for (i = 0; i < t->etm_regs_count; i++)
if (t->etm_regs[i] == etm_regs)
break;
for (; i < t->etm_regs_count - 1; i++)
t->etm_regs[i] = t->etm_regs[i + 1];
t->etm_regs_count--;
if (!t->etm_regs_count) {
kfree(t->etm_regs);
t->etm_regs = NULL;
}
mutex_unlock(&t->mutex);
iounmap(etm_regs);
amba_release_regions(dev);
return 0;
}
static struct amba_id etm_ids[] = {
{
.id = 0x0003b921,
.mask = 0x0007ffff,
},
{
.id = 0x0003b950,
.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;
mutex_init(&tracer.mutex);
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);