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author | Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2018-10-05 15:42:55 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-10-11 12:12:54 +0200 |
commit | d279a38020d2483cb75f5f82f5e4ab5f73bc94f2 (patch) | |
tree | 0b7140fd53dfd22d275117be65803b3a15cf403b /drivers | |
parent | c7fd62bc69d0224877a49383e606f0fe52cba741 (diff) | |
download | linux-stable-d279a38020d2483cb75f5f82f5e4ab5f73bc94f2.tar.gz linux-stable-d279a38020d2483cb75f5f82f5e4ab5f73bc94f2.tar.bz2 linux-stable-d279a38020d2483cb75f5f82f5e4ab5f73bc94f2.zip |
stm class: Add a helper for writing data packets
Add a helper to write a sequence of bytes as STP data packets. This
is used by protocol drivers to output their metadata, as well as the
actual data payload.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/hwtracing/stm/core.c | 51 | ||||
-rw-r--r-- | drivers/hwtracing/stm/stm.h | 3 |
2 files changed, 41 insertions, 13 deletions
diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c index 915af2541dcd..b789a5f0688e 100644 --- a/drivers/hwtracing/stm/core.c +++ b/drivers/hwtracing/stm/core.c @@ -569,27 +569,52 @@ stm_assign_first_policy(struct stm_device *stm, struct stm_output *output, return err; } -static ssize_t notrace stm_write(struct stm_data *data, unsigned int master, - unsigned int channel, const char *buf, size_t count) +/** + * stm_data_write() - send the given payload as data packets + * @data: stm driver's data + * @m: STP master + * @c: STP channel + * @ts_first: timestamp the first packet + * @buf: data payload buffer + * @count: data payload size + */ +ssize_t notrace stm_data_write(struct stm_data *data, unsigned int m, + unsigned int c, bool ts_first, const void *buf, + size_t count) { - unsigned int flags = STP_PACKET_TIMESTAMPED; - const unsigned char *p = buf, nil = 0; - size_t pos; + unsigned int flags = ts_first ? STP_PACKET_TIMESTAMPED : 0; ssize_t sz; + size_t pos; - for (pos = 0, p = buf; count > pos; pos += sz, p += sz) { + for (pos = 0, sz = 0; pos < count; pos += sz) { sz = min_t(unsigned int, count - pos, 8); - sz = data->packet(data, master, channel, STP_PACKET_DATA, flags, - sz, p); - flags = 0; - - if (sz < 0) + sz = data->packet(data, m, c, STP_PACKET_DATA, flags, sz, + &((u8 *)buf)[pos]); + if (sz <= 0) break; + + if (ts_first) { + flags = 0; + ts_first = false; + } } - data->packet(data, master, channel, STP_PACKET_FLAG, 0, 0, &nil); + return sz < 0 ? sz : pos; +} +EXPORT_SYMBOL_GPL(stm_data_write); + +static ssize_t notrace stm_write(struct stm_data *data, unsigned int master, + unsigned int channel, const char *buf, size_t count) +{ + const unsigned char nil = 0; + ssize_t sz; + + sz = stm_data_write(data, master, channel, true, buf, count); + if (sz > 0) + data->packet(data, master, channel, STP_PACKET_FLAG, 0, 0, + &nil); - return pos; + return sz; } static ssize_t stm_char_write(struct file *file, const char __user *buf, diff --git a/drivers/hwtracing/stm/stm.h b/drivers/hwtracing/stm/stm.h index ed7f3d07fa47..3569439d53bb 100644 --- a/drivers/hwtracing/stm/stm.h +++ b/drivers/hwtracing/stm/stm.h @@ -110,5 +110,8 @@ int stm_lookup_protocol(const char *name, const struct stm_protocol_driver **pdrv, const struct config_item_type **type); void stm_put_protocol(const struct stm_protocol_driver *pdrv); +ssize_t stm_data_write(struct stm_data *data, unsigned int m, + unsigned int c, bool ts_first, const void *buf, + size_t count); #endif /* _STM_STM_H_ */ |