2c81ca7fba
Add two sets of tracepoints to be used around RTAS entry:
* rtas_input/rtas_output, which emit the function name, its inputs,
the returned status, and any other outputs. These produce an API-level
record of OS<->RTAS activity.
* rtas_ll_entry/rtas_ll_exit, which are lower-level and emit the
entire contents of the parameter block (aka rtas_args) on entry and
exit. Likely useful only for debugging.
With uses of these tracepoints in do_enter_rtas() to be added in the
following patch, examples of get-time-of-day and event-scan functions
as rendered by trace-cmd (with some multi-line formatting manually
imposed on the rtas_ll_* entries to avoid extremely long lines in the
commit message):
cat-36800 [059] 4978.518303: rtas_input: get-time-of-day arguments:
cat-36800 [059] 4978.518306: rtas_ll_entry: token=3 nargs=0 nret=8
params: [0]=0x00000000 [1]=0x00000000 [2]=0x00000000 [3]=0x00000000
[4]=0x00000000 [5]=0x00000000 [6]=0x00000000 [7]=0x00000000
[8]=0x00000000 [9]=0x00000000 [10]=0x00000000 [11]=0x00000000
[12]=0x00000000 [13]=0x00000000 [14]=0x00000000 [15]=0x00000000
cat-36800 [059] 4978.518366: rtas_ll_exit: token=3 nargs=0 nret=8
params: [0]=0x00000000 [1]=0x000007e6 [2]=0x0000000b [3]=0x00000001
[4]=0x00000000 [5]=0x0000000e [6]=0x00000008 [7]=0x2e0dac40
[8]=0x00000000 [9]=0x00000000 [10]=0x00000000 [11]=0x00000000
[12]=0x00000000 [13]=0x00000000 [14]=0x00000000 [15]=0x00000000
cat-36800 [059] 4978.518366: rtas_output: get-time-of-day status: 0, other outputs: 2022 11 1 0 14 8 772648000
kworker/39:1-336 [039] 4982.731623: rtas_input: event-scan arguments: 4294967295 0 80484920 2048
kworker/39:1-336 [039] 4982.731626: rtas_ll_entry: token=6 nargs=4 nret=1
params: [0]=0xffffffff [1]=0x00000000 [2]=0x04cc1a38 [3]=0x00000800
[4]=0x00000000 [5]=0x0000000e [6]=0x00000008 [7]=0x2e0dac40
[8]=0x00000000 [9]=0x00000000 [10]=0x00000000 [11]=0x00000000
[12]=0x00000000 [13]=0x00000000 [14]=0x00000000 [15]=0x00000000
kworker/39:1-336 [039] 4982.731676: rtas_ll_exit: token=6 nargs=4 nret=1
params: [0]=0xffffffff [1]=0x00000000 [2]=0x04cc1a38 [3]=0x00000800
[4]=0x00000001 [5]=0x0000000e [6]=0x00000008 [7]=0x2e0dac40
[8]=0x00000000 [9]=0x00000000 [10]=0x00000000 [11]=0x00000000
[12]=0x00000000 [13]=0x00000000 [14]=0x00000000 [15]=0x00000000
kworker/39:1-336 [039] 4982.731677: rtas_output: event-scan status: 1, other outputs:
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-10-26929c8cce78@linux.ibm.com
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.