s390/cpumf: enable using AUX buffer

Modify PMU callback to use AUX buffer for diagnostic mode sampling.
Basic-mode sampling still use orignal way.

Signed-off-by: Pu Hou <bjhoupu@linux.vnet.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c
index 51dbd8d90dbe848f180acfb1cb6674e97e1aa282..b9248a70b23266f424043042f27ba967977e2477 100644 (file)
--- a/arch/s390/kernel/perf_cpum_sf.c
+++ b/arch/s390/kernel/perf_cpum_sf.c
@@ -780,6 +780,10 @@ static int __hw_perf_event_init(struct perf_event *event)
        hwc->extra_reg.reg = REG_OVERFLOW;
        OVERFLOW_REG(hwc) = 0;
 
+       /* Use AUX buffer. No need to allocate it by ourself */
+       if (attr->config == PERF_EVENT_CPUM_SF_DIAG)
+               return 0;
+
        /* Allocate the per-CPU sampling buffer using the CPU information
         * from the event.  If the event is not pinned to a particular
         * CPU (event->cpu == -1; or cpuhw == NULL), allocate sampling
@@ -876,10 +880,15 @@ static void cpumsf_pmu_enable(struct pmu *pmu)
         */
        if (cpuhw->event) {
                hwc = &cpuhw->event->hw;
-               /* Account number of overflow-designated buffer extents */
-               sfb_account_overflows(cpuhw, hwc);
-               if (sfb_has_pending_allocs(&cpuhw->sfb, hwc))
-                       extend_sampling_buffer(&cpuhw->sfb, hwc);
+               if (!(SAMPL_DIAG_MODE(hwc))) {
+                       /*
+                        * Account number of overflow-designated
+                        * buffer extents
+                        */
+                       sfb_account_overflows(cpuhw, hwc);
+                       if (sfb_has_pending_allocs(&cpuhw->sfb, hwc))
+                               extend_sampling_buffer(&cpuhw->sfb, hwc);
+               }
        }
 
        /* (Re)enable the PMU and sampling facility */
@@ -1225,6 +1234,13 @@ static void hw_perf_event_update(struct perf_event *event, int flush_all)
        unsigned long long event_overflow, sampl_overflow, num_sdb, te_flags;
        int done;
 
+       /*
+        * AUX buffer is used when in diagnostic sampling mode.
+        * No perf events/samples are created.
+        */
+       if (SAMPL_DIAG_MODE(&event->hw))
+               return;
+
        if (flush_all && SDB_FULL_BLOCKS(hwc))
                flush_all = 0;
 
@@ -1785,12 +1801,13 @@ static void cpumsf_pmu_stop(struct perf_event *event, int flags)
 static int cpumsf_pmu_add(struct perf_event *event, int flags)
 {
        struct cpu_hw_sf *cpuhw = this_cpu_ptr(&cpu_hw_sf);
+       struct aux_buffer *aux;
        int err;
 
        if (cpuhw->flags & PMU_F_IN_USE)
                return -EAGAIN;
 
-       if (!cpuhw->sfb.sdbt)
+       if (!SAMPL_DIAG_MODE(&event->hw) && !cpuhw->sfb.sdbt)
                return -EINVAL;
 
        err = 0;
@@ -1805,10 +1822,12 @@ static int cpumsf_pmu_add(struct perf_event *event, int flags)
         */
        cpuhw->lsctl.s = 0;
        cpuhw->lsctl.h = 1;
-       cpuhw->lsctl.tear = (unsigned long) cpuhw->sfb.sdbt;
-       cpuhw->lsctl.dear = *(unsigned long *) cpuhw->sfb.sdbt;
        cpuhw->lsctl.interval = SAMPL_RATE(&event->hw);
-       hw_reset_registers(&event->hw, cpuhw->sfb.sdbt);
+       if (!SAMPL_DIAG_MODE(&event->hw)) {
+               cpuhw->lsctl.tear = (unsigned long) cpuhw->sfb.sdbt;
+               cpuhw->lsctl.dear = *(unsigned long *) cpuhw->sfb.sdbt;
+               hw_reset_registers(&event->hw, cpuhw->sfb.sdbt);
+       }
 
        /* Ensure sampling functions are in the disabled state.  If disabled,
         * switch on sampling enable control. */
@@ -1816,9 +1835,18 @@ static int cpumsf_pmu_add(struct perf_event *event, int flags)
                err = -EAGAIN;
                goto out;
        }
-       cpuhw->lsctl.es = 1;
-       if (SAMPL_DIAG_MODE(&event->hw))
+       if (SAMPL_DIAG_MODE(&event->hw)) {
+               aux = perf_aux_output_begin(&cpuhw->handle, event);
+               if (!aux) {
+                       err = -EINVAL;
+                       goto out;
+               }
+               err = aux_output_begin(&cpuhw->handle, aux, cpuhw);
+               if (err)
+                       goto out;
                cpuhw->lsctl.ed = 1;
+       }
+       cpuhw->lsctl.es = 1;
 
        /* Set in_use flag and store event */
        cpuhw->event = event;
@@ -1844,6 +1872,8 @@ static void cpumsf_pmu_del(struct perf_event *event, int flags)
        cpuhw->flags &= ~PMU_F_IN_USE;
        cpuhw->event = NULL;
 
+       if (SAMPL_DIAG_MODE(&event->hw))
+               aux_output_end(&cpuhw->handle);
        perf_event_update_userpage(event);
        perf_pmu_enable(event->pmu);
 }
@@ -1917,7 +1947,10 @@ static void cpumf_measurement_alert(struct ext_code ext_code,
        /* Program alert request */
        if (alert & CPU_MF_INT_SF_PRA) {
                if (cpuhw->flags & PMU_F_IN_USE)
-                       hw_perf_event_update(cpuhw->event, 0);
+                       if (SAMPL_DIAG_MODE(&cpuhw->event->hw))
+                               hw_collect_aux(cpuhw);
+                       else
+                               hw_perf_event_update(cpuhw->event, 0);
                else
                        WARN_ON_ONCE(!(cpuhw->flags & PMU_F_IN_USE));
        }