From a72a8a5f2ea32074e98803d4b15d0e093c5a9e4d Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Mon, 28 Sep 2009 17:35:20 -0700 Subject: sparc64: Add a basic conflict engine in preparation for multi-counter support. The hardware counter ->event_base state records and encoding of the "struct perf_event_map" entry used for the event. We use this to make sure that when we have more than 1 event, both can be scheduled into the hardware at the same time. As usual, structure of code is largely cribbed from powerpc. Signed-off-by: David S. Miller --- arch/sparc/kernel/perf_event.c | 69 +++++++++++++++++++++++++++++++++++++++--- 1 file changed, 64 insertions(+), 5 deletions(-) (limited to 'arch/sparc') diff --git a/arch/sparc/kernel/perf_event.c b/arch/sparc/kernel/perf_event.c index 919952498155..2b7743466ae4 100644 --- a/arch/sparc/kernel/perf_event.c +++ b/arch/sparc/kernel/perf_event.c @@ -68,6 +68,17 @@ struct perf_event_map { #define PIC_LOWER 0x02 }; +static unsigned long perf_event_encode(const struct perf_event_map *pmap) +{ + return ((unsigned long) pmap->encoding << 16) | pmap->pic_mask; +} + +static void perf_event_decode(unsigned long val, u16 *enc, u8 *msk) +{ + *msk = val & 0xff; + *enc = val >> 16; +} + #define C(x) PERF_COUNT_HW_CACHE_##x #define CACHE_OP_UNSUPPORTED 0xfffe @@ -713,6 +724,48 @@ static void hw_perf_event_destroy(struct perf_event *event) perf_event_release_pmc(); } +/* Make sure all events can be scheduled into the hardware at + * the same time. This is simplified by the fact that we only + * need to support 2 simultaneous HW events. + */ +static int sparc_check_constraints(unsigned long *events, int n_ev) +{ + if (n_ev <= perf_max_events) { + u8 msk1, msk2; + u16 dummy; + + if (n_ev == 1) + return 0; + BUG_ON(n_ev != 2); + perf_event_decode(events[0], &dummy, &msk1); + perf_event_decode(events[1], &dummy, &msk2); + + /* If both events can go on any counter, OK. */ + if (msk1 == (PIC_UPPER | PIC_LOWER) && + msk2 == (PIC_UPPER | PIC_LOWER)) + return 0; + + /* If one event is limited to a specific counter, + * and the other can go on both, OK. + */ + if ((msk1 == PIC_UPPER || msk1 == PIC_LOWER) && + msk2 == (PIC_UPPER | PIC_LOWER)) + return 0; + if ((msk2 == PIC_UPPER || msk2 == PIC_LOWER) && + msk1 == (PIC_UPPER | PIC_LOWER)) + return 0; + + /* If the events are fixed to different counters, OK. */ + if ((msk1 == PIC_UPPER && msk2 == PIC_LOWER) || + (msk1 == PIC_LOWER && msk2 == PIC_UPPER)) + return 0; + + /* Otherwise, there is a conflict. */ + } + + return -1; +} + static int check_excludes(struct perf_event **evts, int n_prev, int n_new) { int eu = 0, ek = 0, eh = 0; @@ -742,7 +795,7 @@ static int check_excludes(struct perf_event **evts, int n_prev, int n_new) } static int collect_events(struct perf_event *group, int max_count, - struct perf_event *evts[], u64 *events) + struct perf_event *evts[], unsigned long *events) { struct perf_event *event; int n = 0; @@ -751,7 +804,7 @@ static int collect_events(struct perf_event *group, int max_count, if (n >= max_count) return -1; evts[n] = group; - events[n++] = group->hw.config; + events[n++] = group->hw.event_base; } list_for_each_entry(event, &group->sibling_list, group_entry) { if (!is_software_event(event) && @@ -759,7 +812,7 @@ static int collect_events(struct perf_event *group, int max_count, if (n >= max_count) return -1; evts[n] = event; - events[n++] = event->hw.config; + events[n++] = event->hw.event_base; } } return n; @@ -770,8 +823,9 @@ static int __hw_perf_event_init(struct perf_event *event) struct perf_event_attr *attr = &event->attr; struct perf_event *evts[MAX_HWEVENTS]; struct hw_perf_event *hwc = &event->hw; + unsigned long events[MAX_HWEVENTS]; const struct perf_event_map *pmap; - u64 enc, events[MAX_HWEVENTS]; + u64 enc; int n; if (atomic_read(&nmi_active) < 0) @@ -800,6 +854,8 @@ static int __hw_perf_event_init(struct perf_event *event) if (!attr->exclude_hv) hwc->config_base |= sparc_pmu->hv_bit; + hwc->event_base = perf_event_encode(pmap); + enc = pmap->encoding; n = 0; @@ -810,12 +866,15 @@ static int __hw_perf_event_init(struct perf_event *event) if (n < 0) return -EINVAL; } - events[n] = enc; + events[n] = hwc->event_base; evts[n] = event; if (check_excludes(evts, n, 1)) return -EINVAL; + if (sparc_check_constraints(events, n + 1)) + return -EINVAL; + /* Try to do all error checking before this point, as unwinding * state after grabbing the PMC is difficult. */ -- cgit v1.2.1