[PATCH v4 11/21] perf test attr: Introduce mask_bits(), generalizing hide_core_pmu_type()

[Arnaldo Carvalho de Melo <acme@kernel.org>]

From: Arnaldo Carvalho de Melo <acme@redhat.com>

What hide_core_pmu_type() does is take a set of bits out of each of the
'|'-separated alternatives in a value, wildcards included, keeping the
rest of the expression: extract that as mask_bits() and implement
hide_core_pmu_type() in terms of it, a prep for using the same thing to
ignore, when comparing expectations, the sample id bit perf ends up
asking for and the read_format group bit that a PMU count can remove.

No change in behaviour.

Assisted-by: LLM
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/tests/shell/lib/attr.py | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/tools/perf/tests/shell/lib/attr.py b/tools/perf/tests/shell/lib/attr.py
index fb866fb75175dc95..ee55fbe6f07bd7b5 100644
--- a/tools/perf/tests/shell/lib/attr.py
+++ b/tools/perf/tests/shell/lib/attr.py
@@ -80,24 +80,31 @@ PERF_TYPE_HW_CACHE = 3
 # type in its top 32 bits when there is more than one core PMU.
 LEGACY_TYPES = (str(PERF_TYPE_HARDWARE), str(PERF_TYPE_HW_CACHE))
 
-def hide_core_pmu_type(value):
+def mask_bits(value, bits):
     """
-    The kernel can be told which core PMU a legacy type event is meant for by
-    putting its type in the top 32 bits of 'config', which perf only does when
-    there is more than one core PMU, so take those bits out to keep the
-    expectations written for the single core PMU case matching on
-    heterogeneous machines.
+    Take the bits in 'bits' out of each of the '|'-separated alternatives in
+    'value', keeping the rest of the expression, wildcards included.
     """
-    hidden = []
+    masked = []
 
     for alternative in value.split('|'):
         try:
-            alternative = str(int(alternative, 0) & 0xffffffff)
+            alternative = str(int(alternative, 0) & ~bits)
         except ValueError:
             pass
-        hidden.append(alternative)
+        masked.append(alternative)
 
-    return '|'.join(hidden)
+    return '|'.join(masked)
+
+def hide_core_pmu_type(value):
+    """
+    The kernel can be told which core PMU a legacy type event is meant for by
+    putting its type in the top 32 bits of 'config', which perf only does when
+    there is more than one core PMU, so take those bits out to keep the
+    expectations written for the single core PMU case matching on
+    heterogeneous machines.
+    """
+    return mask_bits(value, 0xffffffff00000000)
 
 class Fail(Exception):
     def __init__(self, test, msg):
-- 
2.55.0