linux/drivers/hwtracing/stm/p_sys-t.c

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// SPDX-License-Identifier: GPL-2.0
/*
* MIPI SyS-T framing protocol for STM devices.
* Copyright (c) 2018, Intel Corporation.
*/
#include <linux/configfs.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/uuid.h>
#include <linux/stm.h>
#include "stm.h"
enum sys_t_message_type {
MIPI_SYST_TYPE_BUILD = 0,
MIPI_SYST_TYPE_SHORT32,
MIPI_SYST_TYPE_STRING,
MIPI_SYST_TYPE_CATALOG,
MIPI_SYST_TYPE_RAW = 6,
MIPI_SYST_TYPE_SHORT64,
MIPI_SYST_TYPE_CLOCK,
};
enum sys_t_message_severity {
MIPI_SYST_SEVERITY_MAX = 0,
MIPI_SYST_SEVERITY_FATAL,
MIPI_SYST_SEVERITY_ERROR,
MIPI_SYST_SEVERITY_WARNING,
MIPI_SYST_SEVERITY_INFO,
MIPI_SYST_SEVERITY_USER1,
MIPI_SYST_SEVERITY_USER2,
MIPI_SYST_SEVERITY_DEBUG,
};
enum sys_t_message_build_subtype {
MIPI_SYST_BUILD_ID_COMPACT32 = 0,
MIPI_SYST_BUILD_ID_COMPACT64,
MIPI_SYST_BUILD_ID_LONG,
};
enum sys_t_message_clock_subtype {
MIPI_SYST_CLOCK_TRANSPORT_SYNC = 1,
};
enum sys_t_message_string_subtype {
MIPI_SYST_STRING_GENERIC = 1,
MIPI_SYST_STRING_FUNCTIONENTER,
MIPI_SYST_STRING_FUNCTIONEXIT,
MIPI_SYST_STRING_INVALIDPARAM = 5,
MIPI_SYST_STRING_ASSERT = 7,
MIPI_SYST_STRING_PRINTF_32 = 11,
MIPI_SYST_STRING_PRINTF_64 = 12,
};
#define MIPI_SYST_TYPE(t) ((u32)(MIPI_SYST_TYPE_ ## t))
#define MIPI_SYST_SEVERITY(s) ((u32)(MIPI_SYST_SEVERITY_ ## s) << 4)
#define MIPI_SYST_OPT_LOC BIT(8)
#define MIPI_SYST_OPT_LEN BIT(9)
#define MIPI_SYST_OPT_CHK BIT(10)
#define MIPI_SYST_OPT_TS BIT(11)
#define MIPI_SYST_UNIT(u) ((u32)(u) << 12)
#define MIPI_SYST_ORIGIN(o) ((u32)(o) << 16)
#define MIPI_SYST_OPT_GUID BIT(23)
#define MIPI_SYST_SUBTYPE(s) ((u32)(MIPI_SYST_ ## s) << 24)
#define MIPI_SYST_UNITLARGE(u) (MIPI_SYST_UNIT(u & 0xf) | \
MIPI_SYST_ORIGIN(u >> 4))
#define MIPI_SYST_TYPES(t, s) (MIPI_SYST_TYPE(t) | \
MIPI_SYST_SUBTYPE(t ## _ ## s))
#define DATA_HEADER (MIPI_SYST_TYPES(STRING, GENERIC) | \
MIPI_SYST_SEVERITY(INFO) | \
MIPI_SYST_OPT_GUID)
#define CLOCK_SYNC_HEADER (MIPI_SYST_TYPES(CLOCK, TRANSPORT_SYNC) | \
MIPI_SYST_SEVERITY(MAX))
struct sys_t_policy_node {
uuid_t uuid;
bool do_len;
unsigned long ts_interval;
unsigned long clocksync_interval;
};
struct sys_t_output {
struct sys_t_policy_node node;
unsigned long ts_jiffies;
unsigned long clocksync_jiffies;
};
static void sys_t_policy_node_init(void *priv)
{
struct sys_t_policy_node *pn = priv;
generate_random_uuid(pn->uuid.b);
}
static int sys_t_output_open(void *priv, struct stm_output *output)
{
struct sys_t_policy_node *pn = priv;
struct sys_t_output *opriv;
opriv = kzalloc(sizeof(*opriv), GFP_ATOMIC);
if (!opriv)
return -ENOMEM;
memcpy(&opriv->node, pn, sizeof(opriv->node));
output->pdrv_private = opriv;
return 0;
}
static void sys_t_output_close(struct stm_output *output)
{
kfree(output->pdrv_private);
}
static ssize_t sys_t_policy_uuid_show(struct config_item *item,
char *page)
{
struct sys_t_policy_node *pn = to_pdrv_policy_node(item);
return sprintf(page, "%pU\n", &pn->uuid);
}
static ssize_t
sys_t_policy_uuid_store(struct config_item *item, const char *page,
size_t count)
{
struct mutex *mutexp = &item->ci_group->cg_subsys->su_mutex;
struct sys_t_policy_node *pn = to_pdrv_policy_node(item);
int ret;
mutex_lock(mutexp);
ret = uuid_parse(page, &pn->uuid);
mutex_unlock(mutexp);
return ret < 0 ? ret : count;
}
CONFIGFS_ATTR(sys_t_policy_, uuid);
static ssize_t sys_t_policy_do_len_show(struct config_item *item,
char *page)
{
struct sys_t_policy_node *pn = to_pdrv_policy_node(item);
return sprintf(page, "%d\n", pn->do_len);
}
static ssize_t
sys_t_policy_do_len_store(struct config_item *item, const char *page,
size_t count)
{
struct mutex *mutexp = &item->ci_group->cg_subsys->su_mutex;
struct sys_t_policy_node *pn = to_pdrv_policy_node(item);
int ret;
mutex_lock(mutexp);
ret = kstrtobool(page, &pn->do_len);
mutex_unlock(mutexp);
return ret ? ret : count;
}
CONFIGFS_ATTR(sys_t_policy_, do_len);
static ssize_t sys_t_policy_ts_interval_show(struct config_item *item,
char *page)
{
struct sys_t_policy_node *pn = to_pdrv_policy_node(item);
return sprintf(page, "%u\n", jiffies_to_msecs(pn->ts_interval));
}
static ssize_t
sys_t_policy_ts_interval_store(struct config_item *item, const char *page,
size_t count)
{
struct mutex *mutexp = &item->ci_group->cg_subsys->su_mutex;
struct sys_t_policy_node *pn = to_pdrv_policy_node(item);
unsigned int ms;
int ret;
mutex_lock(mutexp);
ret = kstrtouint(page, 10, &ms);
mutex_unlock(mutexp);
if (!ret) {
pn->ts_interval = msecs_to_jiffies(ms);
return count;
}
return ret;
}
CONFIGFS_ATTR(sys_t_policy_, ts_interval);
static ssize_t sys_t_policy_clocksync_interval_show(struct config_item *item,
char *page)
{
struct sys_t_policy_node *pn = to_pdrv_policy_node(item);
return sprintf(page, "%u\n", jiffies_to_msecs(pn->clocksync_interval));
}
static ssize_t
sys_t_policy_clocksync_interval_store(struct config_item *item,
const char *page, size_t count)
{
struct mutex *mutexp = &item->ci_group->cg_subsys->su_mutex;
struct sys_t_policy_node *pn = to_pdrv_policy_node(item);
unsigned int ms;
int ret;
mutex_lock(mutexp);
ret = kstrtouint(page, 10, &ms);
mutex_unlock(mutexp);
if (!ret) {
pn->clocksync_interval = msecs_to_jiffies(ms);
return count;
}
return ret;
}
CONFIGFS_ATTR(sys_t_policy_, clocksync_interval);
static struct configfs_attribute *sys_t_policy_attrs[] = {
&sys_t_policy_attr_uuid,
&sys_t_policy_attr_do_len,
&sys_t_policy_attr_ts_interval,
&sys_t_policy_attr_clocksync_interval,
NULL,
};
static inline bool sys_t_need_ts(struct sys_t_output *op)
{
if (op->node.ts_interval &&
time_after(op->ts_jiffies + op->node.ts_interval, jiffies)) {
op->ts_jiffies = jiffies;
return true;
}
return false;
}
static bool sys_t_need_clock_sync(struct sys_t_output *op)
{
if (op->node.clocksync_interval &&
time_after(op->clocksync_jiffies + op->node.clocksync_interval,
jiffies)) {
op->clocksync_jiffies = jiffies;
return true;
}
return false;
}
static ssize_t
sys_t_clock_sync(struct stm_data *data, unsigned int m, unsigned int c)
{
u32 header = CLOCK_SYNC_HEADER;
const unsigned char nil = 0;
u64 payload[2]; /* Clock value and frequency */
ssize_t sz;
sz = data->packet(data, m, c, STP_PACKET_DATA, STP_PACKET_TIMESTAMPED,
4, (u8 *)&header);
if (sz <= 0)
return sz;
payload[0] = ktime_get_real_ns();
payload[1] = NSEC_PER_SEC;
sz = stm_data_write(data, m, c, false, &payload, sizeof(payload));
if (sz <= 0)
return sz;
data->packet(data, m, c, STP_PACKET_FLAG, 0, 0, &nil);
return sizeof(header) + sizeof(payload);
}
static ssize_t sys_t_write(struct stm_data *data, struct stm_output *output,
unsigned int chan, const char *buf, size_t count)
{
struct sys_t_output *op = output->pdrv_private;
unsigned int c = output->channel + chan;
unsigned int m = output->master;
const unsigned char nil = 0;
u32 header = DATA_HEADER;
ssize_t sz;
/* We require an existing policy node to proceed */
if (!op)
return -EINVAL;
if (sys_t_need_clock_sync(op)) {
sz = sys_t_clock_sync(data, m, c);
if (sz <= 0)
return sz;
}
if (op->node.do_len)
header |= MIPI_SYST_OPT_LEN;
if (sys_t_need_ts(op))
header |= MIPI_SYST_OPT_TS;
/*
* STP framing rules for SyS-T frames:
* * the first packet of the SyS-T frame is timestamped;
* * the last packet is a FLAG.
*/
/* Message layout: HEADER / GUID / [LENGTH /][TIMESTAMP /] DATA */
/* HEADER */
sz = data->packet(data, m, c, STP_PACKET_DATA, STP_PACKET_TIMESTAMPED,
4, (u8 *)&header);
if (sz <= 0)
return sz;
/* GUID */
sz = stm_data_write(data, m, c, false, op->node.uuid.b, UUID_SIZE);
if (sz <= 0)
return sz;
/* [LENGTH] */
if (op->node.do_len) {
u16 length = count;
sz = data->packet(data, m, c, STP_PACKET_DATA, 0, 2,
(u8 *)&length);
if (sz <= 0)
return sz;
}
/* [TIMESTAMP] */
if (header & MIPI_SYST_OPT_TS) {
u64 ts = ktime_get_real_ns();
sz = stm_data_write(data, m, c, false, &ts, sizeof(ts));
if (sz <= 0)
return sz;
}
/* DATA */
sz = stm_data_write(data, m, c, false, buf, count);
if (sz > 0)
data->packet(data, m, c, STP_PACKET_FLAG, 0, 0, &nil);
return sz;
}
static const struct stm_protocol_driver sys_t_pdrv = {
.owner = THIS_MODULE,
.name = "p_sys-t",
.priv_sz = sizeof(struct sys_t_policy_node),
.write = sys_t_write,
.policy_attr = sys_t_policy_attrs,
.policy_node_init = sys_t_policy_node_init,
.output_open = sys_t_output_open,
.output_close = sys_t_output_close,
};
static int sys_t_stm_init(void)
{
return stm_register_protocol(&sys_t_pdrv);
}
static void sys_t_stm_exit(void)
{
stm_unregister_protocol(&sys_t_pdrv);
}
module_init(sys_t_stm_init);
module_exit(sys_t_stm_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("MIPI SyS-T STM framing protocol driver");
MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");