Re: [PATCH v3 02/11] perf: add PMU_FORMAT_RANGE() helper for use by sw-like pmus
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From: Michael Ellerman <mpe@ellerman.id.au>
Date: 2014-03-04 05:19:40
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On Thu, 2014-27-02 at 21:04:55 UTC, Cody P Schafer wrote:
quoted hunk ↗ jump to hunk
Add PMU_FORMAT_RANGE() and PMU_FORMAT_RANGE_RESERVED() (for reserved areas) which generate functions to extract the relevent bits from event->attr.config{,1,2} for use by sw-like pmus where the 'config{,1,2}' values don't map directly to hardware registers. Signed-off-by: Cody P Schafer <redacted> --- include/linux/perf_event.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index e56b07f..3da5081 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h@@ -871,4 +871,21 @@ _name##_show(struct device *dev, \ \ static struct device_attribute format_attr_##_name = __ATTR_RO(_name) +#define PMU_FORMAT_RANGE(name, attr_var, bit_start, bit_end) \ +PMU_FORMAT_ATTR(name, #attr_var ":" #bit_start "-" #bit_end); \ +PMU_FORMAT_RANGE_RESERVED(name, attr_var, bit_start, bit_end)
I really think these should have event in the name. Someone looking at the code is going to see event_get_foo() and wonder where that is defined. Grep won't find a definition, tags won't find a definition, the least you can do is have the macro name give some hint.
+#define PMU_FORMAT_RANGE_RESERVED(name, attr_var, bit_start, bit_end) \
It doesn't generate a format attribute.
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+static u64 event_get_##name##_max(void) \ +{ \ + int bits = (bit_end) - (bit_start) + 1; \ + return ((0x1ULL << (bits - 1ULL)) - 1ULL) | \ + (0xFULL << (bits - 4ULL)); \
What's wrong with: (0x1ULL << ((bit_end) - (bit_start) + 1)) - 1ULL; cheers