/* Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
*
* Description: CoreSight Embedded Trace Buffer driver
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <asm/local.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/pm_runtime.h>
#include <linux/seq_file.h>
#include <linux/coresight.h>
#include <linux/amba/bus.h>
#include <linux/clk.h>
#include <linux/circ_buf.h>
#include <linux/mm.h>
#include <linux/perf_event.h>
#include <asm/local.h>
#include "coresight-priv.h"
#define ETB_RAM_DEPTH_REG 0x004
#define ETB_STATUS_REG 0x00c
#define ETB_RAM_READ_DATA_REG 0x010
#define ETB_RAM_READ_POINTER 0x014
#define ETB_RAM_WRITE_POINTER 0x018
#define ETB_TRG 0x01c
#define ETB_CTL_REG 0x020
#define ETB_RWD_REG 0x024
#define ETB_FFSR 0x300
#define ETB_FFCR 0x304
#define ETB_ITMISCOP0 0xee0
#define ETB_ITTRFLINACK 0xee4
#define ETB_ITTRFLIN 0xee8
#define ETB_ITATBDATA0 0xeeC
#define ETB_ITATBCTR2 0xef0
#define ETB_ITATBCTR1 0xef4
#define ETB_ITATBCTR0 0xef8
/* register description */
/* STS - 0x00C */
#define ETB_STATUS_RAM_FULL BIT(0)
/* CTL - 0x020 */
#define ETB_CTL_CAPT_EN BIT(0)
/* FFCR - 0x304 */
#define ETB_FFCR_EN_FTC BIT(0)
#define ETB_FFCR_FON_MAN BIT(6)
#define ETB_FFCR_STOP_FI BIT(12)
#define ETB_FFCR_STOP_TRIGGER BIT(13)
#define ETB_FFCR_BIT 6
#define ETB_FFSR_BIT 1
#define ETB_FRAME_SIZE_WORDS 4
/**
* struct etb_drvdata - specifics associated to an ETB component
* @base: memory mapped base address for this component.
* @dev: the device entity associated to this component.
* @atclk: optional clock for the core parts of the ETB.
* @csdev: component vitals needed by the framework.
* @miscdev: specifics to handle "/dev/xyz.etb" entry.
* @spinlock: only one at a time pls.
* @reading: synchronise user space access to etb buffer.
* @mode: this ETB is being used.
* @buf: area of memory where ETB buffer content gets sent.
* @buffer_depth: size of @buf.
* @trigger_cntr: amount of words to store after a trigger.
*/
struct etb_drvdata {
void __iomem *base;
struct device *dev;
struct clk *atclk;
struct coresight_device *csdev;
struct miscdevice miscdev;
spinlock_t spinlock;
local_t reading;
local_t mode;
u8 *buf;
u32 buffer_depth;
u32 trigger_cntr;
};
static unsigned int etb_get_buffer_depth(struct etb_drvdata *drvdata)
{
u32 depth = 0;
pm_runtime_get_sync(drvdata->dev);
/* RO registers don't need locking */
depth = readl_relaxed(drvdata->base + ETB_RAM_DEPTH_REG);
pm_runtime_put(drvdata->dev);
return depth;
}
static void etb_enable_hw(struct etb_drvdata *drvdata)
{
int i;
u32 depth;
CS_UNLOCK(drvdata->base);
depth = drvdata->buffer_depth;
/* reset write RAM pointer address */
writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
/* clear entire RAM buffer */
for (i = 0; i < depth; i++)
writel_relaxed(0x0, drvdata->base + ETB_RWD_REG);
/* reset write RAM pointer address */
writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
/* reset read RAM pointer address */
writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
writel_relaxed(drvdata->trigger_cntr, drvdata->base + ETB_TRG);
writel_relaxed(ETB_FFCR_EN_FTC | ETB_FFCR_STOP_TRIGGER,
drvdata->base + ETB_FFCR);
/* ETB trace capture enable */
writel_relaxed(ETB_CTL_CAPT_EN, drvdata->base + ETB_CTL_REG);
CS_LOCK(drvdata->base);
}
static int etb_enable(struct coresight_device *csdev, u32 mode)
{
u32 val;
unsigned long flags;
struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
val = local_cmpxchg(&drvdata->mode,
CS_MODE_DISABLED, mode);
/*
* When accessing from Perf, a HW buffer can be handled
* by a single trace entity. In sysFS mode many tracers
* can be logging to the same HW buffer.
*/
if (val == CS_MODE_PERF)
return -EBUSY;
/* Nothing to do, the tracer is already enabled. */
if (val == CS_MODE_SYSFS)
goto out;
spin_lock_irqsave(&drvdata->spinlock, flags);
etb_enable_hw(drvdata);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
out:
dev_info(drvdata->dev, "ETB enabled\n");
return 0;
}
static void etb_disable_hw(struct etb_drvdata *drvdata)
{
u32 ffcr;
CS_UNLOCK(drvdata->base);
ffcr = readl_relaxed(drvdata->base + ETB_FFCR);
/* stop formatter when a stop has completed */
ffcr |= ETB_FFCR_STOP_FI;
writel_relaxed(ffcr, drvdata->base + ETB_FFCR);
/* manually generate a flush of the system */
ffcr |= ETB_FFCR_FON_MAN;
writel_relaxed(ffcr, drvdata->base + ETB_FFCR);
if (coresight_timeout(drvdata->base, ETB_FFCR, ETB_FFCR_BIT, 0)) {
dev_err(drvdata->dev,
"timeout while waiting for completion of Manual Flush\n");
}
/* disable trace capture */
writel_relaxed(0x0, drvdata->base + ETB_CTL_REG);
if (coresight_timeout(drvdata->base, ETB_FFSR, ETB_FFSR_BIT, 1)) {
dev_err(drvdata->dev,
"timeout while waiting for Formatter to Stop\n");
}
CS_LOCK(drvdata->base);
}
static void etb_dump_hw(struct etb_drvdata *drvdata)
{
int i;
u8 *buf_ptr;
u32 read_data, depth;
u32 read_ptr, write_ptr;
u32 frame_off, frame_endoff;
CS_UNLOCK(drvdata->base);
read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
frame_off = write_ptr % ETB_FRAME_SIZE_WORDS;
frame_endoff = ETB_FRAME_SIZE_WORDS - frame_off;
if (frame_off) {
dev_err(drvdata->dev,
"write_ptr: %lu not aligned to formatter frame size\n",
(unsigned long)write_ptr);
dev_err(drvdata->dev, "frameoff: %lu, frame_endoff: %lu\n",
(unsigned long)frame_off, (unsigned long)frame_endoff);
write_ptr += frame_endoff;
}
if ((readl_relaxed(drvdata->base + ETB_STATUS_REG)
& ETB_STATUS_RAM_FULL) == 0)
writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
else
writel_relaxed(write_ptr, drvdata->base + ETB_RAM_READ_POINTER);
depth = drvdata->buffer_depth;
buf_ptr = drvdata->buf;
for (i = 0; i < depth; i++) {
read_data = readl_relaxed(drvdata->base +
ETB_RAM_READ_DATA_REG);
*buf_ptr++ = read_data >> 0;
*buf_ptr++ = read_data >> 8;
*buf_ptr++ = read_data >> 16;
*buf_ptr++ = read_data >> 24;
}
if (frame_off) {
buf_ptr -= (frame_endoff * 4);
for (i = 0; i < frame_endoff; i++) {
*buf_ptr++ = 0x0;
*buf_ptr++ = 0x0;
*buf_ptr++ = 0x0;
*buf_ptr++ = 0x0;
}
}
writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);
CS_LOCK(drvdata->base);
}
static void etb_disable(struct coresight_device *csdev)
{
struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
unsigned long flags;
spin_lock_irqsave(&drvdata->spinlock, flags);
etb_disable_hw(drvdata);
etb_dump_hw(drvdata);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
local_set(&drvdata->mode, CS_MODE_DISABLED);
dev_info(drvdata->dev, "ETB disabled\n");
}
static void *etb_alloc_buffer(struct coresight_device *csdev, int cpu,
void **pages, int nr_pages, bool overwrite)
{
int node;
struct cs_buffers *buf;
if (cpu == -1)
cpu = smp_processor_id();
node = cpu_to_node(cpu);
buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node);
if (!buf)
return NULL;
buf->snapshot = overwrite;
buf->nr_pages = nr_pages;
buf->data_pages = pages;
return buf;
}
static void etb_free_buffer(void *config)
{
struct cs_buffers *buf = config;
kfree(buf);
}
static int etb_set_buffer(struct coresight_device *csdev,
struct perf_output_handle *handle,
void *sink_config)
{
int ret = 0;
unsigned long head;
struct cs_buffers *buf = sink_config;
/* wrap head around to the amount of space we have */
head = handle->head & ((buf->nr_pages << PAGE_SHIFT) - 1);
/* find the page to write to */
buf->cur = head / PAGE_SIZE;
/* and offset within that page */
buf->offset = head % PAGE_SIZE;
local_set(&buf->data_size, 0);
return ret;
}
static unsigned long etb_reset_buffer(struct coresight_device *csdev,
struct perf_output_handle *handle,
void *sink_config)
{
unsigned long size = 0;
struct cs_buffers *buf = sink_config;
if (buf) {
/*
* In snapshot mode ->data_size holds the new address of the
* ring buffer's head. The size itself is the whole address
* range since we want the latest information.
*/
if (buf->snapshot)
handle->head = local_xchg(&buf->data_size,
buf->nr_pages << PAGE_SHIFT);
/*
* Tell the tracer PMU how much we got in this run and if
* something went wrong along the way. Nobody else can use
* this cs_buffers instance until we are done. As such
* resetting parameters here and squaring off with the ring
* buffer API in the tracer PMU is fine.
*/
size = local_xchg(&buf->data_size, 0);
}
return size;
}
static void etb_update_buffer(struct coresight_device *csdev,
struct perf_output_handle *handle,
void *sink_config)
{
int i, cur;
u8 *buf_ptr;
u32 read_ptr, write_ptr, capacity;
u32 status, read_data, to_read;
unsigned long offset;
struct cs_buffers *buf = sink_config;
struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
if (!buf)
return;
capacity = drvdata->buffer_depth * ETB_FRAME_SIZE_WORDS;
CS_UNLOCK(drvdata->base);
etb_disable_hw(drvdata);
/* unit is in words, not bytes */
read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
/*
* Entries should be aligned to the frame size. If they are not
* go back to the last alignement point to give decoding tools a
* chance to fix things.
*/
if (write_ptr % ETB_FRAME_SIZE_WORDS) {
dev_err(drvdata->dev,
"write_ptr: %lu not aligned to formatter frame size\n",
(unsigned long)write_ptr);
write_ptr &= ~(ETB_FRAME_SIZE_WORDS - 1);
perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
}
/*
* Get a hold of the status register and see if a wrap around
* has occurred. If so adjust things accordingly. Otherwise
* start at the beginning and go until the write pointer has
* been reached.
*/
status = readl_relaxed(drvdata->base + ETB_STATUS_REG);
if (status & ETB_STATUS_RAM_FULL) {
perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
to_read = capacity;
read_ptr = write_ptr;
} else {
to_read = CIRC_CNT(write_ptr, read_ptr, drvdata->buffer_depth);
to_read *= ETB_FRAME_SIZE_WORDS;
}
/*
* Make sure we don't overwrite data that hasn't been consumed yet.
* It is entirely possible that the HW buffer has more data than the
* ring buffer can currently handle. If so adjust the start address
* to take only the last traces.
*
* In snapshot mode we are looking to get the latest traces only and as
* such, we don't care about not overwriting data that hasn't been
* processed by user space.
*/
if (!buf->snapshot && to_read > handle->size) {
u32 mask = ~(ETB_FRAME_SIZE_WORDS - 1);
/* The new read pointer must be frame size aligned */
to_read = handle->size & mask;
/*
* Move the RAM read pointer up, keeping in mind that
* everything is in frame size units.
*/
read_ptr = (write_ptr + drvdata->buffer_depth) -
to_read / ETB_FRAME_SIZE_WORDS;
/* Wrap around if need be*/
if (read_ptr > (drvdata->buffer_depth - 1))
read_ptr -= drvdata->buffer_depth;
/* let the decoder know we've skipped ahead */
perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
}
/* finally tell HW where we want to start reading from */
writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);
cur = buf->cur;
offset = buf->offset;
for (i = 0; i < to_read; i += 4) {
buf_ptr = buf->data_pages[cur] + offset;
read_data = readl_relaxed(drvdata->base +
ETB_RAM_READ_DATA_REG);
*buf_ptr++ = read_data >> 0;
*buf_ptr++ = read_data >> 8;
*buf_ptr++ = read_data >> 16;
*buf_ptr++ = read_data >> 24;
offset += 4;
if (offset >= PAGE_SIZE) {
offset = 0;
cur++;
/* wrap around at the end of the buffer */
cur &= buf->nr_pages - 1;
}
}
/* reset ETB buffer for next run */
writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
/*
* In snapshot mode all we have to do is communicate to
* perf_aux_output_end() the address of the current head. In full
* trace mode the same function expects a size to move rb->aux_head
* forward.
*/
if (buf->snapshot)
local_set(&buf->data_size, (cur * PAGE_SIZE) + offset);
else
local_add(to_read, &buf->data_size);
etb_enable_hw(drvdata);
CS_LOCK(drvdata->base);
}
static const struct coresight_ops_sink etb_sink_ops = {
.enable = etb_enable,
.disable = etb_disable,
.alloc_buffer = etb_alloc_buffer,
.free_buffer = etb_free_buffer,
.set_buffer = etb_set_buffer,
.reset_buffer = etb_reset_buffer,
.update_buffer = etb_update_buffer,
};
static const struct coresight_ops etb_cs_ops = {
.sink_ops = &etb_sink_ops,
};
static void etb_dump(struct etb_drvdata *drvdata)
{
unsigned long flags;
spin_lock_irqsave(&drvdata->spinlock, flags);
if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
etb_disable_hw(drvdata);
etb_dump_hw(drvdata);
etb_enable_hw(drvdata);
}
spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_info(drvdata->dev, "ETB dumped\n");
}
static int etb_open(struct inode *inode, struct file *file)
{
struct etb_drvdata *drvdata = container_of(file->private_data,
struct etb_drvdata, miscdev);
if (local_cmpxchg(&drvdata->reading, 0, 1))
return -EBUSY;
dev_dbg(drvdata->dev, "%s: successfully opened\n", __func__);
return 0;
}
static ssize_t etb_read(struct file *file, char __user *data,
size_t len, loff_t *ppos)
{
u32 depth;
struct etb_drvdata *drvdata = container_of(file->private_data,
struct etb_drvdata, miscdev);
etb_dump(drvdata);
depth = drvdata->buffer_depth;
if (*ppos + len > depth * 4)
len = depth * 4 - *ppos;
if (copy_to_user(data, drvdata->buf + *ppos, len)) {
dev_dbg(drvdata->dev, "%s: copy_to_user failed\n", __func__);
return -EFAULT;
}
*ppos += len;
dev_dbg(drvdata->dev, "%s: %zu bytes copied, %d bytes left\n",
__func__, len, (int)(depth * 4 - *ppos));
return len;
}
static int etb_release(struct inode *inode, struct file *file)
{
struct etb_drvdata *drvdata = container_of(file->private_data,
struct etb_drvdata, miscdev);
local_set(&drvdata->reading, 0);
dev_dbg(drvdata->dev, "%s: released\n", __func__);
return 0;
}
static const struct file_operations etb_fops = {
.owner = THIS_MODULE,
.open = etb_open,
.read = etb_read,
.release = etb_release,
.llseek = no_llseek,
};
#define coresight_etb10_simple_func(name, offset) \
coresight_simple_func(struct etb_drvdata, NULL, name, offset)
coresight_etb10_simple_func(rdp, ETB_RAM_DEPTH_REG);
coresight_etb10_simple_func(sts, ETB_STATUS_REG);
coresight_etb10_simple_func(rrp, ETB_RAM_READ_POINTER);
coresight_etb10_simple_func(rwp, ETB_RAM_WRITE_POINTER);
coresight_etb10_simple_func(trg, ETB_TRG);
coresight_etb10_simple_func(ctl, ETB_CTL_REG);
coresight_etb10_simple_func(ffsr, ETB_FFSR);
coresight_etb10_simple_func(ffcr, ETB_FFCR);
static struct attribute *coresight_etb_mgmt_attrs[] = {
&dev_attr_rdp.attr,
&dev_attr_sts.attr,
&dev_attr_rrp.attr,
&dev_attr_rwp.attr,
&dev_attr_trg.attr,
&dev_attr_ctl.attr,
&dev_attr_ffsr.attr,
&dev_attr_ffcr.attr,
NULL,
};
static ssize_t trigger_cntr_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
unsigned long val = drvdata->trigger_cntr;
return sprintf(buf, "%#lx\n", val);
}
static ssize_t trigger_cntr_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t size)
{
int ret;
unsigned long val;
struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
ret = kstrtoul(buf, 16, &val);
if (ret)
return ret;
drvdata->trigger_cntr = val;
return size;
}
static DEVICE_ATTR_RW(trigger_cntr);
static struct attribute *coresight_etb_attrs[] = {
&dev_attr_trigger_cntr.attr,
NULL,
};
static const struct attribute_group coresight_etb_group = {
.attrs = coresight_etb_attrs,
};
static const struct attribute_group coresight_etb_mgmt_group = {
.attrs = coresight_etb_mgmt_attrs,
.name = "mgmt",
};
const struct attribute_group *coresight_etb_groups[] = {
&coresight_etb_group,
&coresight_etb_mgmt_group,
NULL,
};
static int etb_probe(struct amba_device *adev, const struct amba_id *id)
{
int ret;
void __iomem *base;
struct device *dev = &adev->dev;
struct coresight_platform_data *pdata = NULL;
struct etb_drvdata *drvdata;
struct resource *res = &adev->res;
struct coresight_desc desc = { 0 };
struct device_node *np = adev->dev.of_node;
if (np) {
pdata = of_get_coresight_platform_data(dev, np);
if (IS_ERR(pdata))
return PTR_ERR(pdata);
adev->dev.platform_data = pdata;
}
drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
if (!drvdata)
return -ENOMEM;
drvdata->dev = &adev->dev;
drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
if (!IS_ERR(drvdata->atclk)) {
ret = clk_prepare_enable(drvdata->atclk);
if (ret)
return ret;
}
dev_set_drvdata(dev, drvdata);
/* validity for the resource is already checked by the AMBA core */
base = devm_ioremap_resource(dev, res);
if (IS_ERR(base))
return PTR_ERR(base);
drvdata->base = base;
spin_lock_init(&drvdata->spinlock);
drvdata->buffer_depth = etb_get_buffer_depth(drvdata);
pm_runtime_put(&adev->dev);
if (drvdata->buffer_depth & 0x80000000)
return -EINVAL;
drvdata->buf = devm_kzalloc(dev,
drvdata->buffer_depth * 4, GFP_KERNEL);
if (!drvdata->buf) {
dev_err(dev, "Failed to allocate %u bytes for buffer data\n",
drvdata->buffer_depth * 4);
return -ENOMEM;
}
desc.type = CORESIGHT_DEV_TYPE_SINK;
desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER;
desc.ops = &etb_cs_ops;
desc.pdata = pdata;
desc.dev = dev;
desc.groups = coresight_etb_groups;
drvdata->csdev = coresight_register(&desc);
if (IS_ERR(drvdata->csdev))
return PTR_ERR(drvdata->csdev);
drvdata->miscdev.name = pdata->name;
drvdata->miscdev.minor = MISC_DYNAMIC_MINOR;
drvdata->miscdev.fops = &etb_fops;
ret = misc_register(&drvdata->miscdev);
if (ret)
goto err_misc_register;
return 0;
err_misc_register:
coresight_unregister(drvdata->csdev);
return ret;
}
#ifdef CONFIG_PM
static int etb_runtime_suspend(struct device *dev)
{
struct etb_drvdata *drvdata = dev_get_drvdata(dev);
if (drvdata && !IS_ERR(drvdata->atclk))
clk_disable_unprepare(drvdata->atclk);
return 0;
}
static int etb_runtime_resume(struct device *dev)
{
struct etb_drvdata *drvdata = dev_get_drvdata(dev);
if (drvdata && !IS_ERR(drvdata->atclk))
clk_prepare_enable(drvdata->atclk);
return 0;
}
#endif
static const struct dev_pm_ops etb_dev_pm_ops = {
SET_RUNTIME_PM_OPS(etb_runtime_suspend, etb_runtime_resume, NULL)
};
static struct amba_id etb_ids[] = {
{
.id = 0x0003b907,
.mask = 0x0003ffff,
},
{ 0, 0},
};
static struct amba_driver etb_driver = {
.drv = {
.name = "coresight-etb10",
.owner = THIS_MODULE,
.pm = &etb_dev_pm_ops,
.suppress_bind_attrs = true,
},
.probe = etb_probe,
.id_table = etb_ids,
};
builtin_amba_driver(etb_driver);