perf tools: Add infrastructure for PMU specific configuration

This patch adds PMU driver specific configuration to the parser
infrastructure by preceding any term with the '@' letter.  As such doing
something like:

perf record -e some_event/@cfg1,@cfg2=config/ ...

will see 'cfg1' and 'cfg2=config' being added to the list of evsel
config terms.  Token 'cfg1' and 'cfg2=config' are not processed in user
space and are meant to be interpreted by the PMU driver.

First the lexer/parser are supplemented with the required definitions to
recognise the driver specific configuration.  From there they are simply
added to the list of event terms.  The bulk of the work is done in
function "parse_events_add_pmu()" where driver config event terms are
added to a new list of driver config terms, which in turn spliced with
the event's new driver configuration list.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1473179837-3293-4-git-send-email-mathieu.poirier@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 379a2bed07c0..1a24f4d64328 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -60,6 +60,18 @@ OPTIONS
 	  Note: If user explicitly sets options which conflict with the params,
 	  the value set by the params will be overridden.
 
+	  Also not defined in .../<pmu>/format/* are PMU driver specific
+	  configuration parameters.  Any configuration parameter preceded by
+	  the letter '@' is not interpreted in user space and sent down directly
+	  to the PMU driver.  For example:
+
+	  perf record -e some_event/@cfg1,@cfg2=config/ ...
+
+	  will see 'cfg1' and 'cfg2=config' pushed to the PMU driver associated
+	  with the event for further processing.  There is no restriction on
+	  what the configuration parameters are, as long as their semantic is
+	  understood and supported by the PMU driver.
+
         - a hardware breakpoint event in the form of '\mem:addr[/len][:access]'
           where addr is the address in memory you want to break in.
           Access is the memory access type (read, write, execute) it can