diff options
Diffstat (limited to 'drivers/hwtracing/stm/p_sys-t.c')
| -rw-r--r-- | drivers/hwtracing/stm/p_sys-t.c | 93 |
1 files changed, 85 insertions, 8 deletions
diff --git a/drivers/hwtracing/stm/p_sys-t.c b/drivers/hwtracing/stm/p_sys-t.c index 8254971c02..1e75aa0025 100644 --- a/drivers/hwtracing/stm/p_sys-t.c +++ b/drivers/hwtracing/stm/p_sys-t.c @@ -20,6 +20,7 @@ enum sys_t_message_type { MIPI_SYST_TYPE_RAW = 6, MIPI_SYST_TYPE_SHORT64, MIPI_SYST_TYPE_CLOCK, + MIPI_SYST_TYPE_SBD, }; enum sys_t_message_severity { @@ -53,6 +54,19 @@ enum sys_t_message_string_subtype { 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) @@ -75,6 +89,20 @@ enum sys_t_message_string_subtype { #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; @@ -284,14 +312,67 @@ sys_t_clock_sync(struct stm_data *data, unsigned int m, unsigned int c) 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) + 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; - const unsigned char nil = 0; - u32 header = DATA_HEADER; + u32 header = sys_t_header(source); u8 uuid[UUID_SIZE]; ssize_t sz; @@ -348,11 +429,7 @@ static ssize_t sys_t_write(struct stm_data *data, struct stm_output *output, } /* 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; + return sys_t_write_data(data, source, m, c, false, buf, count); } static const struct stm_protocol_driver sys_t_pdrv = { |