Use the ftrace infrastructure to conditionally trace ufs command events.
New trace event is created, which samples the following ufs command data:
- device name
- optional identification string
- task tag
- doorbell register
- number of transfer bytes
- interrupt status register
- request start LBA
- command opcode
Currently we only fully trace read(10) and write(10) commands.
All other commands which pass through ufshcd_send_command() will be
printed with "-1" in the lba and transfer_len fields.
Usage:
echo 1 > /sys/kernel/debug/tracing/events/ufs/enable
cat /sys/kernel/debug/tracing/trace_pipe
Change-Id: Id6e16a8c0b2a833c5453ed9923384f641e374a71
Signed-off-by: Lee Susman <lsusman@codeaurora.org>
[gbroner@codeaurora.org: fix merge conflict]
Signed-off-by: Gilad Broner <gbroner@codeaurora.org>
[subhashj@codeaurora.org: resolved merge conflicts and compilation error]
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
b0c1404cb0