Markus Elfring <markus.elfr...@web.de> writes:
> From: Markus Elfring <elfr...@users.sourceforge.net>
> Date: Mon, 16 Sep 2024 19:25:00 +0200
>
> Scope-based resource management became supported for some
> programming interfaces by contributions of Peter Zijlstra on 2023-05-26.
> See also the commit 54da6a0924311c7cf5015533991e44fb8eb12773 ("locking:
> Introduce __cleanup() based infrastructure").
>
> * Thus replace local_irq_save() and local_irq_restore() calls by calls
> of the macro “guard(irqsave)”.
>
> * Omit the local variables “flags” and “irq_flags”.
>
> * Replace selected usage of the label “out” by a few return statements.
>
>
> This issue was detected by using the Coccinelle software.
>
> Signed-off-by: Markus Elfring <elfr...@users.sourceforge.net>
> ---
> arch/powerpc/perf/core-book3s.c | 102 +++++++++++++-------------------
> 1 file changed, 42 insertions(+), 60 deletions(-)
These mostly look good.
I don't think the change to power_pmu_event_init() is an improvement.
I'll drop that hunk when applying, or you can send a v2 without that
change if you prefer.
cheers
> @@ -1996,7 +1980,7 @@ static bool is_event_blacklisted(u64 ev)
> static int power_pmu_event_init(struct perf_event *event)
> {
> u64 ev;
> - unsigned long flags, irq_flags;
> + unsigned long flags;
> struct perf_event *ctrs[MAX_HWEVENTS];
> u64 events[MAX_HWEVENTS];
> unsigned int cflags[MAX_HWEVENTS];
> @@ -2115,43 +2099,41 @@ static int power_pmu_event_init(struct perf_event
> *event)
> if (check_excludes(ctrs, cflags, n, 1))
> return -EINVAL;
>
> - local_irq_save(irq_flags);
> - cpuhw = this_cpu_ptr(&cpu_hw_events);
> + {
> + guard(irqsave)();
> + cpuhw = this_cpu_ptr(&cpu_hw_events);
>
> - err = power_check_constraints(cpuhw, events, cflags, n + 1, ctrs);
> + err = power_check_constraints(cpuhw, events, cflags, n + 1,
> ctrs);
>
> - if (has_branch_stack(event)) {
> - u64 bhrb_filter = -1;
> + if (has_branch_stack(event)) {
> + u64 bhrb_filter = -1;
>
> - /*
> - * Currently no PMU supports having multiple branch filters
> - * at the same time. Branch filters are set via MMCRA IFM[32:33]
> - * bits for Power8 and above. Return EOPNOTSUPP when multiple
> - * branch filters are requested in the event attr.
> - *
> - * When opening event via perf_event_open(), branch_sample_type
> - * gets adjusted in perf_copy_attr(). Kernel will automatically
> - * adjust the branch_sample_type based on the event modifier
> - * settings to include PERF_SAMPLE_BRANCH_PLM_ALL. Hence drop
> - * the check for PERF_SAMPLE_BRANCH_PLM_ALL.
> - */
> - if (hweight64(event->attr.branch_sample_type &
> ~PERF_SAMPLE_BRANCH_PLM_ALL) > 1) {
> - local_irq_restore(irq_flags);
> - return -EOPNOTSUPP;
> - }
> + /*
> + * Currently no PMU supports having multiple branch
> filters
> + * at the same time. Branch filters are set via MMCRA
> IFM[32:33]
> + * bits for Power8 and above. Return EOPNOTSUPP when
> multiple
> + * branch filters are requested in the event attr.
> + *
> + * When opening event via perf_event_open(),
> branch_sample_type
> + * gets adjusted in perf_copy_attr(). Kernel will
> automatically
> + * adjust the branch_sample_type based on the event
> modifier
> + * settings to include PERF_SAMPLE_BRANCH_PLM_ALL.
> Hence drop
> + * the check for PERF_SAMPLE_BRANCH_PLM_ALL.
> + */
> + if (hweight64(event->attr.branch_sample_type &
> ~PERF_SAMPLE_BRANCH_PLM_ALL)
> + > 1)
> + return -EOPNOTSUPP;
>
> - if (ppmu->bhrb_filter_map)
> - bhrb_filter = ppmu->bhrb_filter_map(
> - event->attr.branch_sample_type);
> + if (ppmu->bhrb_filter_map)
> + bhrb_filter =
> ppmu->bhrb_filter_map(event->attr.branch_sample_type);
>
> - if (bhrb_filter == -1) {
> - local_irq_restore(irq_flags);
> - return -EOPNOTSUPP;
> + if (bhrb_filter == -1)
> + return -EOPNOTSUPP;
> +
> + cpuhw->bhrb_filter = bhrb_filter;
> }
> - cpuhw->bhrb_filter = bhrb_filter;
> }
>
> - local_irq_restore(irq_flags);
> if (err)
> return -EINVAL;
>
> --
> 2.46.0
