diff options
Diffstat (limited to 'drivers/hwtracing/stm/p_sys-t.c')
| -rw-r--r-- | drivers/hwtracing/stm/p_sys-t.c | 461 |
1 files changed, 461 insertions, 0 deletions
diff --git a/drivers/hwtracing/stm/p_sys-t.c b/drivers/hwtracing/stm/p_sys-t.c new file mode 100644 index 000000000000..1e75aa0025a3 --- /dev/null +++ b/drivers/hwtracing/stm/p_sys-t.c @@ -0,0 +1,461 @@ +// 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, + MIPI_SYST_TYPE_SBD, +}; + +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, +}; + +/** + * enum sys_t_message_sbd_subtype - SyS-T SBD message subtypes + * @MIPI_SYST_SBD_ID32: SBD message with 32-bit message ID + * @MIPI_SYST_SBD_ID64: SBD message with 64-bit message ID + * + * Structured Binary Data messages can send information of arbitrary length, + * together with ID's that describe BLOB's content and layout. + */ +enum sys_t_message_sbd_subtype { + MIPI_SYST_SBD_ID32 = 0, + MIPI_SYST_SBD_ID64 = 1, +}; + +#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)) + +/* + * SyS-T and ftrace headers are compatible to an extent that ftrace event ID + * and args can be treated as SyS-T SBD message with 64-bit ID and arguments + * BLOB right behind the header without modification. Bits [16:63] coming + * together with message ID from ftrace aren't used by SBD and must be zeroed. + * + * 0 15 16 23 24 31 32 39 40 63 + * ftrace: <event_id> <flags> <preempt> <-pid-> <----> <args> + * SBD: <------- msg_id ------------------------------> <BLOB> + */ +#define SBD_HEADER (MIPI_SYST_TYPES(SBD, ID64) | \ + MIPI_SYST_SEVERITY(INFO) | \ + MIPI_SYST_OPT_GUID) + +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; + + uuid_gen(&pn->uuid); +} + +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(jiffies, op->ts_jiffies + op->node.ts_interval)) { + 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(jiffies, + op->clocksync_jiffies + op->node.clocksync_interval)) { + 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 inline u32 sys_t_header(struct stm_source_data *source) +{ + if (source && source->type == STM_FTRACE) + return SBD_HEADER; + return DATA_HEADER; +} + +static ssize_t sys_t_write_data(struct stm_data *data, + struct stm_source_data *source, + unsigned int master, unsigned int channel, + bool ts_first, const void *buf, size_t count) +{ + ssize_t sz; + const unsigned char nil = 0; + + /* + * Ftrace is zero-copy compatible with SyS-T SBD, but requires + * special handling of first 64 bits. Trim and send them separately + * to avoid damage on original ftrace buffer. + */ + if (source && source->type == STM_FTRACE) { + u64 compat_ftrace_header; + ssize_t header_sz; + ssize_t buf_sz; + + if (count < sizeof(compat_ftrace_header)) + return -EINVAL; + + /* SBD only makes use of low 16 bits (event ID) from ftrace event */ + compat_ftrace_header = *(u64 *)buf & 0xffff; + header_sz = stm_data_write(data, master, channel, false, + &compat_ftrace_header, + sizeof(compat_ftrace_header)); + if (header_sz != sizeof(compat_ftrace_header)) + return header_sz; + + buf_sz = stm_data_write(data, master, channel, false, + buf + header_sz, count - header_sz); + if (buf_sz != count - header_sz) + return buf_sz; + sz = header_sz + buf_sz; + } else { + sz = stm_data_write(data, master, channel, false, buf, count); + } + + if (sz <= 0) + return sz; + + data->packet(data, master, channel, STP_PACKET_FLAG, 0, 0, &nil); + + return sz; +} + +static ssize_t sys_t_write(struct stm_data *data, struct stm_output *output, + unsigned int chan, const char *buf, size_t count, + struct stm_source_data *source) +{ + struct sys_t_output *op = output->pdrv_private; + unsigned int c = output->channel + chan; + unsigned int m = output->master; + u32 header = sys_t_header(source); + u8 uuid[UUID_SIZE]; + 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 */ + export_uuid(uuid, &op->node.uuid); + sz = stm_data_write(data, m, c, false, uuid, sizeof(op->node.uuid)); + 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 */ + return sys_t_write_data(data, source, m, c, false, buf, count); +} + +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>"); |