diff options
| -rw-r--r-- | arch/powerpc/perf/hv-24x7.c | 166 |
1 files changed, 164 insertions, 2 deletions
diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c index 527c8b98e97e..9f9dfda9ed2c 100644 --- a/arch/powerpc/perf/hv-24x7.c +++ b/arch/powerpc/perf/hv-24x7.c @@ -142,6 +142,15 @@ static struct attribute_group event_long_desc_group = { static struct kmem_cache *hv_page_cache; +DEFINE_PER_CPU(int, hv_24x7_txn_flags); +DEFINE_PER_CPU(int, hv_24x7_txn_err); + +struct hv_24x7_hw { + struct perf_event *events[255]; +}; + +DEFINE_PER_CPU(struct hv_24x7_hw, hv_24x7_hw); + /* * request_buffer and result_buffer are not required to be 4k aligned, * but are not allowed to cross any 4k boundary. Aligning them to 4k is @@ -1231,9 +1240,48 @@ static void update_event_count(struct perf_event *event, u64 now) static void h_24x7_event_read(struct perf_event *event) { u64 now; + struct hv_24x7_request_buffer *request_buffer; + struct hv_24x7_hw *h24x7hw; + int txn_flags; + + txn_flags = __this_cpu_read(hv_24x7_txn_flags); + + /* + * If in a READ transaction, add this counter to the list of + * counters to read during the next HCALL (i.e commit_txn()). + * If not in a READ transaction, go ahead and make the HCALL + * to read this counter by itself. + */ + + if (txn_flags & PERF_PMU_TXN_READ) { + int i; + int ret; - now = h_24x7_get_value(event); - update_event_count(event, now); + if (__this_cpu_read(hv_24x7_txn_err)) + return; + + request_buffer = (void *)get_cpu_var(hv_24x7_reqb); + + ret = add_event_to_24x7_request(event, request_buffer); + if (ret) { + __this_cpu_write(hv_24x7_txn_err, ret); + } else { + /* + * Assoicate the event with the HCALL request index, + * so ->commit_txn() can quickly find/update count. + */ + i = request_buffer->num_requests - 1; + + h24x7hw = &get_cpu_var(hv_24x7_hw); + h24x7hw->events[i] = event; + put_cpu_var(h24x7hw); + } + + put_cpu_var(hv_24x7_reqb); + } else { + now = h_24x7_get_value(event); + update_event_count(event, now); + } } static void h_24x7_event_start(struct perf_event *event, int flags) @@ -1255,6 +1303,117 @@ static int h_24x7_event_add(struct perf_event *event, int flags) return 0; } +/* + * 24x7 counters only support READ transactions. They are + * always counting and dont need/support ADD transactions. + * Cache the flags, but otherwise ignore transactions that + * are not PERF_PMU_TXN_READ. + */ +static void h_24x7_event_start_txn(struct pmu *pmu, unsigned int flags) +{ + struct hv_24x7_request_buffer *request_buffer; + struct hv_24x7_data_result_buffer *result_buffer; + + /* We should not be called if we are already in a txn */ + WARN_ON_ONCE(__this_cpu_read(hv_24x7_txn_flags)); + + __this_cpu_write(hv_24x7_txn_flags, flags); + if (flags & ~PERF_PMU_TXN_READ) + return; + + request_buffer = (void *)get_cpu_var(hv_24x7_reqb); + result_buffer = (void *)get_cpu_var(hv_24x7_resb); + + init_24x7_request(request_buffer, result_buffer); + + put_cpu_var(hv_24x7_resb); + put_cpu_var(hv_24x7_reqb); +} + +/* + * Clean up transaction state. + * + * NOTE: Ignore state of request and result buffers for now. + * We will initialize them during the next read/txn. + */ +static void reset_txn(void) +{ + __this_cpu_write(hv_24x7_txn_flags, 0); + __this_cpu_write(hv_24x7_txn_err, 0); +} + +/* + * 24x7 counters only support READ transactions. They are always counting + * and dont need/support ADD transactions. Clear ->txn_flags but otherwise + * ignore transactions that are not of type PERF_PMU_TXN_READ. + * + * For READ transactions, submit all pending 24x7 requests (i.e requests + * that were queued by h_24x7_event_read()), to the hypervisor and update + * the event counts. + */ +static int h_24x7_event_commit_txn(struct pmu *pmu) +{ + struct hv_24x7_request_buffer *request_buffer; + struct hv_24x7_data_result_buffer *result_buffer; + struct hv_24x7_result *resb; + struct perf_event *event; + u64 count; + int i, ret, txn_flags; + struct hv_24x7_hw *h24x7hw; + + txn_flags = __this_cpu_read(hv_24x7_txn_flags); + WARN_ON_ONCE(!txn_flags); + + ret = 0; + if (txn_flags & ~PERF_PMU_TXN_READ) + goto out; + + ret = __this_cpu_read(hv_24x7_txn_err); + if (ret) + goto out; + + request_buffer = (void *)get_cpu_var(hv_24x7_reqb); + result_buffer = (void *)get_cpu_var(hv_24x7_resb); + + ret = make_24x7_request(request_buffer, result_buffer); + if (ret) { + log_24x7_hcall(request_buffer, result_buffer, ret); + goto put_reqb; + } + + h24x7hw = &get_cpu_var(hv_24x7_hw); + + /* Update event counts from hcall */ + for (i = 0; i < request_buffer->num_requests; i++) { + resb = &result_buffer->results[i]; + count = be64_to_cpu(resb->elements[0].element_data[0]); + event = h24x7hw->events[i]; + h24x7hw->events[i] = NULL; + update_event_count(event, count); + } + + put_cpu_var(hv_24x7_hw); + +put_reqb: + put_cpu_var(hv_24x7_resb); + put_cpu_var(hv_24x7_reqb); +out: + reset_txn(); + return ret; +} + +/* + * 24x7 counters only support READ transactions. They are always counting + * and dont need/support ADD transactions. However, regardless of type + * of transaction, all we need to do is cleanup, so we don't have to check + * the type of transaction. + */ +static void h_24x7_event_cancel_txn(struct pmu *pmu) +{ + WARN_ON_ONCE(!__this_cpu_read(hv_24x7_txn_flags)); + reset_txn(); +} + static struct pmu h_24x7_pmu = { .task_ctx_nr = perf_invalid_context, @@ -1266,6 +1425,9 @@ static struct pmu h_24x7_pmu = { .start = h_24x7_event_start, .stop = h_24x7_event_stop, .read = h_24x7_event_read, + .start_txn = h_24x7_event_start_txn, + .commit_txn = h_24x7_event_commit_txn, + .cancel_txn = h_24x7_event_cancel_txn, }; static int hv_24x7_init(void) |