// SPDX-License-Identifier: (GPL-2.0 OR MIT)
/*
* Siemens System Memory Buffer driver.
* Copyright(c) 2022, HiSilicon Limited.
*/
#include <linux/atomic.h>
#include <linux/acpi.h>
#include <linux/circ_buf.h>
#include <linux/err.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include "coresight-etm-perf.h"
#include "coresight-priv.h"
#include "ultrasoc-smb.h"
DEFINE_CORESIGHT_DEVLIST(sink_devs, "ultra_smb");
#define ULTRASOC_SMB_DSM_UUID "82ae1283-7f6a-4cbe-aa06-53e8fb24db18"
static bool smb_buffer_not_empty(struct smb_drv_data *drvdata)
{
u32 buf_status = readl(drvdata->base + SMB_LB_INT_STS_REG);
return FIELD_GET(SMB_LB_INT_STS_NOT_EMPTY_MSK, buf_status);
}
static void smb_update_data_size(struct smb_drv_data *drvdata)
{
struct smb_data_buffer *sdb = &drvdata->sdb;
u32 buf_wrptr;
buf_wrptr = readl(drvdata->base + SMB_LB_WR_ADDR_REG) -
sdb->buf_hw_base;
/* Buffer is full */
if (buf_wrptr == sdb->buf_rdptr && smb_buffer_not_empty(drvdata)) {
sdb->data_size = sdb->buf_size;
return;
}
/* The buffer mode is circular buffer mode */
sdb->data_size = CIRC_CNT(buf_wrptr, sdb->buf_rdptr,
sdb->buf_size);
}
/*
* The read pointer adds @nbytes bytes (may round up to the beginning)
* after the data is read or discarded, while needing to update the
* available data size.
*/
static void smb_update_read_ptr(struct smb_drv_data *drvdata, u32 nbytes)
{
struct smb_data_buffer *sdb = &drvdata->sdb;
sdb->buf_rdptr += nbytes;
sdb->buf_rdptr %= sdb->buf_size;
writel(sdb->buf_hw_base + sdb->buf_rdptr,
drvdata->base + SMB_LB_RD_ADDR_REG);
sdb->data_size -= nbytes;
}
static void smb_reset_buffer(struct smb_drv_data *drvdata)
{
struct smb_data_buffer *sdb = &drvdata->sdb;
u32 write_ptr;
/*
* We must flush and discard any data left in hardware path
* to avoid corrupting the next session.
* Note: The write pointer will never exceed the read pointer.
*/
writel(SMB_LB_PURGE_PURGED, drvdata->base + SMB_LB_PURGE_REG);
/* Reset SMB logical buffer status flags */
writel(SMB_LB_INT_STS_RESET, drvdata->base + SMB_LB_INT_STS_REG);
write_ptr = readl(drvdata->base + SMB_LB_WR_ADDR_REG);
/* Do nothing, not data left in hardware path */
if (!write_ptr || write_ptr == sdb->buf_rdptr + sdb->buf_hw_base)
return;
/*
* The SMB_LB_WR_ADDR_REG register is read-only,
* Synchronize the read pointer to write pointer.
*/
writel(write_ptr, drvdata->base + SMB_LB_RD_ADDR_REG);
sdb->buf_rdptr = write_ptr - sdb->buf_hw_base;
}
static int smb_open(struct inode *inode, struct file *file)
{
struct smb_drv_data *drvdata = container_of(file->private_data,
struct smb_drv_data, miscdev);
guard(spinlock)(&drvdata->spinlock);
if (drvdata->reading)
return -EBUSY;
if (drvdata->csdev->refcnt)
return -EBUSY;
smb_update_data_size(drvdata);
drvdata->reading = true;
return 0;
}
static ssize_t smb_read(struct file *file, char __user *data, size_t len,
loff_t *ppos)
{
struct smb_drv_data *drvdata = container_of(file->private_data,
struct smb_drv_data, miscdev);
struct smb_data_buffer *sdb = &drvdata->sdb;
struct device *dev = &drvdata->csdev->dev;
ssize_t to_copy = 0;
if (!len)
return 0;
if (!sdb->data_size)
return 0;
to_copy = min(sdb->data_size, len);
/* Copy parts of trace data when read pointer wrap around SMB buffer */
if (sdb->buf_rdptr + to_copy > sdb->buf_size)
to_copy = sdb->buf_size - sdb->buf_rdptr;
if (copy_to_user(data, sdb->buf_base + sdb->buf_rdptr, to_copy)) {
dev_dbg(dev, "Failed to copy data to user\n");
return -EFAULT;
}
*ppos += to_copy;
smb_update_read_ptr(drvdata, to_copy);
if (!sdb->data_size)
smb_reset_buffer(drvdata);
dev_dbg(dev, "%zu bytes copied\n", to_copy);
return to_copy;
}
static int smb_release(struct inode *inode, struct file *file)
{
struct smb_drv_data *drvdata = container_of(file->private_data,
struct smb_drv_data, miscdev);
guard(spinlock)(&drvdata->spinlock);
drvdata->reading = false;
return 0;
}
static const struct file_operations smb_fops = {
.owner = THIS_MODULE,
.open = smb_open,
.read = smb_read,
.release = smb_release,
};
static ssize_t buf_size_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct smb_drv_data *drvdata = dev_get_drvdata(dev->parent);
return sysfs_emit(buf, "0x%lx\n", drvdata->sdb.buf_size);
}
static DEVICE_ATTR_RO(buf_size);
static struct attribute *smb_sink_attrs[] = {
coresight_simple_reg32(read_pos, SMB_LB_RD_ADDR_REG),
coresight_simple_reg32(write_pos, SMB_LB_WR_ADDR_REG),
coresight_simple_reg32(buf_status, SMB_LB_INT_STS_REG),
&dev_attr_buf_size.attr,
NULL
};
static const struct attribute_group smb_sink_group = {
.attrs = smb_sink_attrs,
.name = "mgmt",
};
static const struct attribute_group *smb_sink_groups[] = {
&smb_sink_group,
NULL
};
static void smb_enable_hw(struct smb_drv_data *drvdata)
{
writel(SMB_GLB_EN_HW_ENABLE, drvdata->base + SMB_GLB_EN_REG);
}
static void smb_disable_hw(struct smb_drv_data *drvdata)
{
writel(0x0, drvdata->base + SMB_GLB_EN_REG);
}
static void smb_enable_sysfs(struct coresight_device *csdev)
{
struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
if (coresight_get_mode(csdev) != CS_MODE_DISABLED)
return;
smb_enable_hw(drvdata);
coresight_set_mode(csdev, CS_MODE_SYSFS);
}
static int smb_enable_perf(struct coresight_device *csdev, void *data)
{
struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
struct perf_output_handle *handle = data;
struct cs_buffers *buf = etm_perf_sink_config(handle);
pid_t pid;
if (!buf)
return -EINVAL;
/* Get a handle on the pid of the target process */
pid = buf->pid;
/* Device is already in used by other session */
if (drvdata->pid != -1 && drvdata->pid != pid)
return -EBUSY;
if (drvdata->pid == -1) {
smb_enable_hw(drvdata);
drvdata->pid = pid;
coresight_set_mode(csdev, CS_MODE_PERF);
}
return 0;
}
static int smb_enable(struct coresight_device *csdev, enum cs_mode mode,
void *data)
{
struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
int ret = 0;
guard(spinlock)(&drvdata->spinlock);
/* Do nothing, the trace data is reading by other interface now */
if (drvdata->reading)
return -EBUSY;
/* Do nothing, the SMB is already enabled as other mode */
if (coresight_get_mode(csdev) != CS_MODE_DISABLED &&
coresight_get_mode(csdev) != mode)
return -EBUSY;
switch (mode) {
case CS_MODE_SYSFS:
smb_enable_sysfs(csdev);
break;
case CS_MODE_PERF:
ret = smb_enable_perf(csdev, data);
break;
default:
ret = -EINVAL;
}
if (ret)
return ret;
csdev->refcnt++;
dev_dbg(&csdev->dev, "Ultrasoc SMB enabled\n");
return ret;
}
static int smb_disable(struct coresight_device *csdev)
{
struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
guard(spinlock)(&drvdata->spinlock);
if (drvdata->reading)
return -EBUSY;
csdev->refcnt--;
if (csdev->refcnt)
return -EBUSY;
/* Complain if we (somehow) got out of sync */
WARN_ON_ONCE(coresight_get_mode(csdev) == CS_MODE_DISABLED);
smb_disable_hw(drvdata);
/* Dissociate from the target process. */
drvdata->pid = -1;
coresight_set_mode(csdev, CS_MODE_DISABLED);
dev_dbg(&csdev->dev, "Ultrasoc SMB disabled\n");
return 0;
}
static void *smb_alloc_buffer(struct coresight_device *csdev,
struct perf_event *event, void **pages,
int nr_pages, bool overwrite)
{
struct cs_buffers *buf;
int node;
node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->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;
buf->pid = task_pid_nr(event->owner);
return buf;
}
static void smb_free_buffer(void *config)
{
struct cs_buffers *buf = config;
kfree(buf);
}
static void smb_sync_perf_buffer(struct smb_drv_data *drvdata,
struct cs_buffers *buf,
unsigned long head)
{
struct smb_data_buffer *sdb = &drvdata->sdb;
char **dst_pages = (char **)buf->data_pages;
unsigned long to_copy;
long pg_idx, pg_offset;
pg_idx = head >> PAGE_SHIFT;
pg_offset = head & (PAGE_SIZE - 1);
while (sdb->data_size) {
unsigned long pg_space = PAGE_SIZE - pg_offset;
to_copy = min(sdb->data_size, pg_space);
/* Copy parts of trace data when read pointer wrap around */
if (sdb->buf_rdptr + to_copy > sdb->buf_size)
to_copy = sdb->buf_size - sdb->buf_rdptr;
memcpy(dst_pages[pg_idx] + pg_offset,
sdb->buf_base + sdb->buf_rdptr, to_copy);
pg_offset += to_copy;
if (pg_offset >= PAGE_SIZE) {
pg_offset = 0;
pg_idx++;
pg_idx %= buf->nr_pages;
}
smb_update_read_ptr(drvdata, to_copy);
}
smb_reset_buffer(drvdata);
}
static unsigned long smb_update_buffer(struct coresight_device *csdev,
struct perf_output_handle *handle,
void *sink_config)
{
struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
struct smb_data_buffer *sdb = &drvdata->sdb;
struct cs_buffers *buf = sink_config;
unsigned long data_size;
bool lost = false;
if (!buf)
return 0;
guard(spinlock)(&drvdata->spinlock);
/* Don't do anything if another tracer is using this sink. */
if (csdev->refcnt != 1)
return 0;
smb_disable_hw(drvdata);
smb_update_data_size(drvdata);
/*
* The SMB buffer may be bigger than the space available in the
* perf ring buffer (handle->size). If so advance the offset so
* that we get the latest trace data.
*/
if (sdb->data_size > handle->size) {
smb_update_read_ptr(drvdata, sdb->data_size - handle->size);
lost = true;
}
data_size = sdb->data_size;
smb_sync_perf_buffer(drvdata, buf, handle->head);
if (!buf->snapshot && lost)
perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
return data_size;
}
static const struct coresight_ops_sink smb_cs_ops = {
.enable = smb_enable,
.disable = smb_disable,
.alloc_buffer = smb_alloc_buffer,
.free_buffer = smb_free_buffer,
.update_buffer = smb_update_buffer,
};
static const struct coresight_ops cs_ops = {
.sink_ops = &smb_cs_ops,
};
static int smb_init_data_buffer(struct platform_device *pdev,
struct smb_data_buffer *sdb)
{
struct resource *res;
void *base;
res = platform_get_resource(pdev, IORESOURCE_MEM, SMB_BUF_ADDR_RES);
if (!res) {
dev_err(&pdev->dev, "SMB device failed to get resource\n");
return -EINVAL;
}
sdb->buf_rdptr = 0;
sdb->buf_hw_base = FIELD_GET(SMB_BUF_ADDR_LO_MSK, res->start);
sdb->buf_size = resource_size(res);
if (sdb->buf_size == 0)
return -EINVAL;
/*
* This is a chunk of memory, use classic mapping with better
* performance.
*/
base = devm_memremap(&pdev->dev, sdb->buf_hw_base, sdb->buf_size,
MEMREMAP_WB);
if (IS_ERR(base))
return PTR_ERR(base);
sdb->buf_base = base;
return 0;
}
static void smb_init_hw(struct smb_drv_data *drvdata)
{
smb_disable_hw(drvdata);
writel(SMB_LB_CFG_LO_DEFAULT, drvdata->base + SMB_LB_CFG_LO_REG);
writel(SMB_LB_CFG_HI_DEFAULT, drvdata->base + SMB_LB_CFG_HI_REG);
writel(SMB_GLB_CFG_DEFAULT, drvdata->base + SMB_GLB_CFG_REG);
writel(SMB_GLB_INT_CFG, drvdata->base + SMB_GLB_INT_REG);
writel(SMB_LB_INT_CTRL_CFG, drvdata->base + SMB_LB_INT_CTRL_REG);
}
static int smb_register_sink(struct platform_device *pdev,
struct smb_drv_data *drvdata)
{
struct coresight_platform_data *pdata = NULL;
struct coresight_desc desc = { 0 };
int ret;
pdata = coresight_get_platform_data(&pdev->dev);
if (IS_ERR(pdata))
return PTR_ERR(pdata);
desc.type = CORESIGHT_DEV_TYPE_SINK;
desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER;
desc.ops = &cs_ops;
desc.pdata = pdata;
desc.dev = &pdev->dev;
desc.groups = smb_sink_groups;
desc.name = coresight_alloc_device_name(&sink_devs, &pdev->dev);
if (!desc.name) {
dev_err(&pdev->dev, "Failed to alloc coresight device name");
return -ENOMEM;
}
desc.access = CSDEV_ACCESS_IOMEM(drvdata->base);
drvdata->csdev = coresight_register(&desc);
if (IS_ERR(drvdata->csdev))
return PTR_ERR(drvdata->csdev);
drvdata->miscdev.name = desc.name;
drvdata->miscdev.minor = MISC_DYNAMIC_MINOR;
drvdata->miscdev.fops = &smb_fops;
ret = misc_register(&drvdata->miscdev);
if (ret) {
coresight_unregister(drvdata->csdev);
dev_err(&pdev->dev, "Failed to register misc, ret=%d\n", ret);
}
return ret;
}
static void smb_unregister_sink(struct smb_drv_data *drvdata)
{
misc_deregister(&drvdata->miscdev);
coresight_unregister(drvdata->csdev);
}
static int smb_config_inport(struct device *dev, bool enable)
{
u64 func = enable ? 1 : 0;
union acpi_object *obj;
guid_t guid;
u64 rev = 0;
/*
* Using DSM calls to enable/disable ultrasoc hardwares on
* tracing path, to prevent ultrasoc packet format being exposed.
*/
if (guid_parse(ULTRASOC_SMB_DSM_UUID, &guid)) {
dev_err(dev, "Get GUID failed\n");
return -EINVAL;
}
obj = acpi_evaluate_dsm(ACPI_HANDLE(dev), &guid, rev, func, NULL);
if (!obj) {
dev_err(dev, "ACPI handle failed\n");
return -ENODEV;
}
ACPI_FREE(obj);
return 0;
}
static int smb_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct smb_drv_data *drvdata;
int ret;
drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
if (!drvdata)
return -ENOMEM;
drvdata->base = devm_platform_ioremap_resource(pdev, SMB_REG_ADDR_RES);
if (IS_ERR(drvdata->base)) {
dev_err(dev, "Failed to ioremap resource\n");
return PTR_ERR(drvdata->base);
}
smb_init_hw(drvdata);
ret = smb_init_data_buffer(pdev, &drvdata->sdb);
if (ret) {
dev_err(dev, "Failed to init buffer, ret = %d\n", ret);
return ret;
}
ret = smb_config_inport(dev, true);
if (ret)
return ret;
smb_reset_buffer(drvdata);
platform_set_drvdata(pdev, drvdata);
spin_lock_init(&drvdata->spinlock);
drvdata->pid = -1;
ret = smb_register_sink(pdev, drvdata);
if (ret) {
smb_config_inport(&pdev->dev, false);
dev_err(dev, "Failed to register SMB sink\n");
return ret;
}
return 0;
}
static void smb_remove(struct platform_device *pdev)
{
struct smb_drv_data *drvdata = platform_get_drvdata(pdev);
smb_unregister_sink(drvdata);
smb_config_inport(&pdev->dev, false);
}
#ifdef CONFIG_ACPI
static const struct acpi_device_id ultrasoc_smb_acpi_match[] = {
{"HISI03A1", 0, 0, 0},
{}
};
MODULE_DEVICE_TABLE(acpi, ultrasoc_smb_acpi_match);
#endif
static struct platform_driver smb_driver = {
.driver = {
.name = "ultrasoc-smb",
.acpi_match_table = ACPI_PTR(ultrasoc_smb_acpi_match),
.suppress_bind_attrs = true,
},
.probe = smb_probe,
.remove_new = smb_remove,
};
module_platform_driver(smb_driver);
MODULE_DESCRIPTION("UltraSoc SMB CoreSight driver");
MODULE_LICENSE("Dual MIT/GPL");
MODULE_AUTHOR("Jonathan Zhou <[email protected]>");
MODULE_AUTHOR("Qi Liu <[email protected]>");
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