Re: [PATCH v2 01/11] perf: add PMU_RANGE_ATTR() helper for use by sw-like pmus
From: Michael Ellerman <mpe@ellerman.id.au>
Date: 2014-02-25 03:33:28
Also in:
linuxppc-dev
On Fri, 2014-14-02 at 22:02:05 UTC, Cody P Schafer wrote:
quoted hunk ↗ jump to hunk
Add PMU_RANGE_ATTR() and PMU_RANGE_RESV() (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..2702e91 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_RANGE_ATTR(name, attr_var, bit_start, bit_end) \ +PMU_FORMAT_ATTR(name, #attr_var ":" #bit_start "-" #bit_end); \ +PMU_RANGE_RESV(name, attr_var, bit_start, bit_end) + +#define PMU_RANGE_RESV(name, attr_var, bit_start, bit_end) \ +static u64 event_get_##name##_max(void) \ +{ \ + int bits = (bit_end) - (bit_start) + 1; \ + return ((0x1ULL << (bits - 1ULL)) - 1ULL) | \ + (0xFULL << (bits - 4ULL)); \ +} \ +static u64 event_get_##name(struct perf_event *event) \ +{ \ + return (event->attr.attr_var >> (bit_start)) & \ + event_get_##name##_max(); \ +}
I still don't like the names. EVENT_GETTER_AND_FORMAT() EVENT_RESERVED() ? It's not clear to me the max routine is useful in general. Can't we just do:
+#define EVENT_RESERVED(name, attr_var, bit_start, bit_end) \
+static u64 event_get_##name(struct perf_event *event) \
+{ \
+ return (event->attr.attr_var >> (bit_start)) & \
+ ((0x1ULL << ((bit_end) - (bit_start) + 1)) - 1ULL); \
+}cheers