On 16/12/2025 22:44, Ian Rogers wrote:
On Fri, Dec 12, 2025 at 7:32 AM James Clark james.clark@linaro.org wrote:
This will be used by aux PMUs to read an already written value for configuring their events and for also testing.
Its helper pmu_format_unpack() does the opposite of the existing pmu_format_value() so rename that one to pmu_format_pack() so it's clear how they are related.
Signed-off-by: James Clark james.clark@linaro.org
tools/perf/util/evsel.h | 2 ++ tools/perf/util/pmu.c | 77 ++++++++++++++++++++++++++++++++++++++++++------- 2 files changed, 68 insertions(+), 11 deletions(-)
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h index a08130ff2e47a887b19f6c47bfa9f51e0c40d226..092904a61ec7afdc59253f9b78a9fe8b7cb5bfa7 100644 --- a/tools/perf/util/evsel.h +++ b/tools/perf/util/evsel.h @@ -575,6 +575,8 @@ void evsel__uniquify_counter(struct evsel *counter); ((((src) >> (pos)) & ((1ull << (size)) - 1)) << (63 - ((pos) + (size) - 1)))
u64 evsel__bitfield_swap_branch_flags(u64 value); +int evsel__get_config_val(struct perf_pmu *pmu, struct evsel *evsel,
const char *config_name, u64 *val);diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c index 514cba91f5d99b399d2d6a1e350971660c54a9fc..ef7358ad1fb955f29f2e68b3d0ce711754e4d67c 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -144,8 +144,8 @@ struct perf_pmu_format { };
static int pmu_aliases_parse(struct perf_pmu *pmu); -static void pmu_format_value(unsigned long *format, __u64 value, __u64 *v,
bool zero);+static void pmu_format_pack(unsigned long *format, __u64 value, __u64 *v,
bool zero);@@ -1377,6 +1377,61 @@ bool evsel__is_aux_event(const struct evsel *evsel) return pmu && pmu->auxtrace; }
+/*
- Unpacks a raw config[n] value using the sparse bitfield that defines a
- format attr. For example "config1:1,6-7,44" defines a 4 bit value across non
- contiguous bits and this function returns those 4 bits as a value.
- */
+static u64 pmu_format_unpack(u64 format, u64 config_val) +{
int val_bit = 0;u64 res = 0;int fmt_bit;for_each_set_bit(fmt_bit, &format, PERF_PMU_FORMAT_BITS) {if (test_bit(fmt_bit, &config_val))res |= BIT_ULL(val_bit);val_bit++;}return res;+}
+int evsel__get_config_val(struct perf_pmu *pmu, struct evsel *evsel,
const char *config_name, u64 *val)nits: This is an evsel__ function but the evsel is the 2nd argument not the first. Why pass the PMU and not just read evsel->pmu (or better evsel__find_pmu) ?
That makes sense, I can do that.
Why not place this in evsel.c to match the header file declaration?
This was for consistency with evsel__set_config_if_unset() that Arnaldo moved to pmu.c because of an issue with the Python bindings [1]. That doesn't seem to be an issue any more so I could move both to evsel.c. That would require making the following things public:
struct perf_pmu_format pmu_format_pack() pmu_format_unpack() pmu_find_format()
Probably not the end of the world though?
[1]: https://lore.kernel.org/all/ZEbAS2yx2fguW60w@kernel.org/
The evsel could be likely be const.
Will do
Thanks, Ian
+{
struct perf_pmu_format *format = pmu_find_format(&pmu->format, config_name);u64 bits = perf_pmu__format_bits(pmu, config_name);if (!format || !bits) {pr_err("Unknown/empty format name: %s\n", config_name);*val = 0;return -EINVAL;}switch (format->value) {case PERF_PMU_FORMAT_VALUE_CONFIG:*val = pmu_format_unpack(bits, evsel->core.attr.config);return 0;case PERF_PMU_FORMAT_VALUE_CONFIG1:*val = pmu_format_unpack(bits, evsel->core.attr.config1);return 0;case PERF_PMU_FORMAT_VALUE_CONFIG2:*val = pmu_format_unpack(bits, evsel->core.attr.config2);return 0;case PERF_PMU_FORMAT_VALUE_CONFIG3:*val = pmu_format_unpack(bits, evsel->core.attr.config3);return 0;case PERF_PMU_FORMAT_VALUE_CONFIG4:*val = pmu_format_unpack(bits, evsel->core.attr.config4);return 0;default:pr_err("Unknown format value: %d\n", format->value);*val = 0;return -EINVAL;}+}
- /*
- Set @config_name to @val as long as the user hasn't already set or cleared it
- by passing a config term on the command line.
@@ -1432,7 +1487,7 @@ void evsel__set_config_if_unset(struct perf_pmu *pmu, struct evsel *evsel, return;
/* Otherwise replace it */
pmu_format_value(&bits, val, vp, /*zero=*/true);
pmu_format_pack(&bits, val, vp, /*zero=*/true);}
static struct perf_pmu_format *
@@ -1477,8 +1532,8 @@ int perf_pmu__format_type(struct perf_pmu *pmu, const char *name)
- Sets value based on the format definition (format parameter)
- and unformatted value (value parameter).
*/ -static void pmu_format_value(unsigned long *format, __u64 value, __u64 *v,
bool zero)+static void pmu_format_pack(unsigned long *format, __u64 value, __u64 *v,
bool zero)@@ -1595,23 +1650,23 @@ static int pmu_config_term(const struct perf_pmu *pmu, switch (term->type_term) { case PARSE_EVENTS__TERM_TYPE_CONFIG: assert(term->type_val == PARSE_EVENTS__TERM_TYPE_NUM);
pmu_format_value(bits, term->val.num, &attr->config, zero);
pmu_format_pack(bits, term->val.num, &attr->config, zero); break; case PARSE_EVENTS__TERM_TYPE_CONFIG1: assert(term->type_val == PARSE_EVENTS__TERM_TYPE_NUM);
pmu_format_value(bits, term->val.num, &attr->config1, zero);
pmu_format_pack(bits, term->val.num, &attr->config1, zero); break; case PARSE_EVENTS__TERM_TYPE_CONFIG2: assert(term->type_val == PARSE_EVENTS__TERM_TYPE_NUM);
pmu_format_value(bits, term->val.num, &attr->config2, zero);
pmu_format_pack(bits, term->val.num, &attr->config2, zero); break; case PARSE_EVENTS__TERM_TYPE_CONFIG3: assert(term->type_val == PARSE_EVENTS__TERM_TYPE_NUM);
pmu_format_value(bits, term->val.num, &attr->config3, zero);
pmu_format_pack(bits, term->val.num, &attr->config3, zero); break; case PARSE_EVENTS__TERM_TYPE_CONFIG4: assert(term->type_val == PARSE_EVENTS__TERM_TYPE_NUM);
pmu_format_value(bits, term->val.num, &attr->config4, zero);
pmu_format_pack(bits, term->val.num, &attr->config4, zero); break; case PARSE_EVENTS__TERM_TYPE_LEGACY_HARDWARE_CONFIG: assert(term->type_val == PARSE_EVENTS__TERM_TYPE_NUM);@@ -1749,7 +1804,7 @@ static int pmu_config_term(const struct perf_pmu *pmu, */ }
pmu_format_value(format->bits, val, vp, zero);
pmu_format_pack(format->bits, val, vp, zero); return 0;-- 2.34.1
-
James Clark