1 files changed, 106 insertions, 92 deletions

diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c
index 544a02e944c6..c07fdcd73726 100644
--- a/arch/s390/kernel/perf_cpum_sf.c
+++ b/arch/s390/kernel/perf_cpum_sf.c
@@ -156,8 +156,8 @@ static void free_sampling_buffer(struct sf_buffer *sfb)
 		}
 	}
 
-	debug_sprintf_event(sfdbg, 5,
-			    "free_sampling_buffer: freed sdbt=%p\n", sfb->sdbt);
+	debug_sprintf_event(sfdbg, 5, "%s: freed sdbt %#lx\n", __func__,
+			    (unsigned long)sfb->sdbt);
 	memset(sfb, 0, sizeof(*sfb));
 }
 
@@ -193,7 +193,7 @@ static int realloc_sampling_buffer(struct sf_buffer *sfb,
 				   unsigned long num_sdb, gfp_t gfp_flags)
 {
 	int i, rc;
-	unsigned long *new, *tail;
+	unsigned long *new, *tail, *tail_prev = NULL;
 
 	if (!sfb->sdbt || !sfb->tail)
 		return -EINVAL;
@@ -212,10 +212,11 @@ static int realloc_sampling_buffer(struct sf_buffer *sfb,
 	 * the sampling buffer origin.
 	 */
 	if (sfb->sdbt != get_next_sdbt(tail)) {
-		debug_sprintf_event(sfdbg, 3, "realloc_sampling_buffer: "
-				    "sampling buffer is not linked: origin=%p"
-				    "tail=%p\n",
-				    (void *) sfb->sdbt, (void *) tail);
+		debug_sprintf_event(sfdbg, 3, "%s: "
+				    "sampling buffer is not linked: origin %#lx"
+				    " tail %#lx\n", __func__,
+				    (unsigned long)sfb->sdbt,
+				    (unsigned long)tail);
 		return -EINVAL;
 	}
 
@@ -232,6 +233,7 @@ static int realloc_sampling_buffer(struct sf_buffer *sfb,
 			sfb->num_sdbt++;
 			/* Link current page to tail of chain */
 			*tail = (unsigned long)(void *) new + 1;
+			tail_prev = tail;
 			tail = new;
 		}
 
@@ -241,18 +243,30 @@ static int realloc_sampling_buffer(struct sf_buffer *sfb,
 		 * issue, a new realloc call (if required) might succeed.
 		 */
 		rc = alloc_sample_data_block(tail, gfp_flags);
-		if (rc)
+		if (rc) {
+			/* Undo last SDBT. An SDBT with no SDB at its first
+			 * entry but with an SDBT entry instead can not be
+			 * handled by the interrupt handler code.
+			 * Avoid this situation.
+			 */
+			if (tail_prev) {
+				sfb->num_sdbt--;
+				free_page((unsigned long) new);
+				tail = tail_prev;
+			}
 			break;
+		}
 		sfb->num_sdb++;
 		tail++;
+		tail_prev = new = NULL;	/* Allocated at least one SBD */
 	}
 
 	/* Link sampling buffer to its origin */
 	*tail = (unsigned long) sfb->sdbt + 1;
 	sfb->tail = tail;
 
-	debug_sprintf_event(sfdbg, 4, "realloc_sampling_buffer: new buffer"
-			    " settings: sdbt=%lu sdb=%lu\n",
+	debug_sprintf_event(sfdbg, 4, "%s: new buffer"
+			    " settings: sdbt %lu sdb %lu\n", __func__,
 			    sfb->num_sdbt, sfb->num_sdb);
 	return rc;
 }
@@ -292,12 +306,13 @@ static int alloc_sampling_buffer(struct sf_buffer *sfb, unsigned long num_sdb)
 	rc = realloc_sampling_buffer(sfb, num_sdb, GFP_KERNEL);
 	if (rc) {
 		free_sampling_buffer(sfb);
-		debug_sprintf_event(sfdbg, 4, "alloc_sampling_buffer: "
-			"realloc_sampling_buffer failed with rc=%i\n", rc);
+		debug_sprintf_event(sfdbg, 4, "%s: "
+			"realloc_sampling_buffer failed with rc %i\n",
+			__func__, rc);
 	} else
 		debug_sprintf_event(sfdbg, 4,
-			"alloc_sampling_buffer: tear=%p dear=%p\n",
-			sfb->sdbt, (void *) *sfb->sdbt);
+			"%s: tear %#lx dear %#lx\n", __func__,
+			(unsigned long)sfb->sdbt, (unsigned long)*sfb->sdbt);
 	return rc;
 }
 
@@ -404,8 +419,8 @@ static int allocate_buffers(struct cpu_hw_sf *cpuhw, struct hw_perf_event *hwc)
 		return 0;
 
 	debug_sprintf_event(sfdbg, 3,
-			    "allocate_buffers: rate=%lu f=%lu sdb=%lu/%lu"
-			    " sample_size=%lu cpuhw=%p\n",
+			    "%s: rate %lu f %lu sdb %lu/%lu"
+			    " sample_size %lu cpuhw %p\n", __func__,
 			    SAMPL_RATE(hwc), freq, n_sdb, sfb_max_limit(hwc),
 			    sample_size, cpuhw);
 
@@ -465,8 +480,8 @@ static void sfb_account_overflows(struct cpu_hw_sf *cpuhw,
 	if (num)
 		sfb_account_allocs(num, hwc);
 
-	debug_sprintf_event(sfdbg, 5, "sfb: overflow: overflow=%llu ratio=%lu"
-			    " num=%lu\n", OVERFLOW_REG(hwc), ratio, num);
+	debug_sprintf_event(sfdbg, 5, "%s: overflow %llu ratio %lu num %lu\n",
+			    __func__, OVERFLOW_REG(hwc), ratio, num);
 	OVERFLOW_REG(hwc) = 0;
 }
 
@@ -504,13 +519,13 @@ static void extend_sampling_buffer(struct sf_buffer *sfb,
 	 */
 	rc = realloc_sampling_buffer(sfb, num, GFP_ATOMIC);
 	if (rc)
-		debug_sprintf_event(sfdbg, 5, "sfb: extend: realloc "
-				    "failed with rc=%i\n", rc);
+		debug_sprintf_event(sfdbg, 5, "%s: realloc failed with rc %i\n",
+				    __func__, rc);
 
 	if (sfb_has_pending_allocs(sfb, hwc))
-		debug_sprintf_event(sfdbg, 5, "sfb: extend: "
-				    "req=%lu alloc=%lu remaining=%lu\n",
-				    num, sfb->num_sdb - num_old,
+		debug_sprintf_event(sfdbg, 5, "%s: "
+				    "req %lu alloc %lu remaining %lu\n",
+				    __func__, num, sfb->num_sdb - num_old,
 				    sfb_pending_allocs(sfb, hwc));
 }
 
@@ -538,20 +553,22 @@ static void setup_pmc_cpu(void *flags)
 		err = sf_disable();
 		if (err)
 			pr_err("Switching off the sampling facility failed "
-			       "with rc=%i\n", err);
+			       "with rc %i\n", err);
 		debug_sprintf_event(sfdbg, 5,
-				    "setup_pmc_cpu: initialized: cpuhw=%p\n", cpusf);
+				    "%s: initialized: cpuhw %p\n", __func__,
+				    cpusf);
 		break;
 	case PMC_RELEASE:
 		cpusf->flags &= ~PMU_F_RESERVED;
 		err = sf_disable();
 		if (err) {
 			pr_err("Switching off the sampling facility failed "
-			       "with rc=%i\n", err);
+			       "with rc %i\n", err);
 		} else
 			deallocate_buffers(cpusf);
 		debug_sprintf_event(sfdbg, 5,
-				    "setup_pmc_cpu: released: cpuhw=%p\n", cpusf);
+				    "%s: released: cpuhw %p\n", __func__,
+				    cpusf);
 		break;
 	}
 	if (err)
@@ -598,13 +615,6 @@ static void hw_init_period(struct hw_perf_event *hwc, u64 period)
 	local64_set(&hwc->period_left, hwc->sample_period);
 }
 
-static void hw_reset_registers(struct hw_perf_event *hwc,
-			       unsigned long *sdbt_origin)
-{
-	/* (Re)set to first sample-data-block-table */
-	TEAR_REG(hwc) = (unsigned long) sdbt_origin;
-}
-
 static unsigned long hw_limit_rate(const struct hws_qsi_info_block *si,
 				   unsigned long rate)
 {
@@ -696,9 +706,9 @@ static unsigned long getrate(bool freq, unsigned long sample,
 		 */
 		if (sample_rate_to_freq(si, rate) >
 		    sysctl_perf_event_sample_rate) {
-			debug_sprintf_event(sfdbg, 1,
+			debug_sprintf_event(sfdbg, 1, "%s: "
 					    "Sampling rate exceeds maximum "
-					    "perf sample rate\n");
+					    "perf sample rate\n", __func__);
 			rate = 0;
 		}
 	}
@@ -743,10 +753,9 @@ static int __hw_perf_event_init_rate(struct perf_event *event,
 	attr->sample_period = rate;
 	SAMPL_RATE(hwc) = rate;
 	hw_init_period(hwc, SAMPL_RATE(hwc));
-	debug_sprintf_event(sfdbg, 4, "__hw_perf_event_init_rate:"
-			    "cpu:%d period:%llx freq:%d,%#lx\n", event->cpu,
-			    event->attr.sample_period, event->attr.freq,
-			    SAMPLE_FREQ_MODE(hwc));
+	debug_sprintf_event(sfdbg, 4, "%s: cpu %d period %#llx freq %d,%#lx\n",
+			    __func__, event->cpu, event->attr.sample_period,
+			    event->attr.freq, SAMPLE_FREQ_MODE(hwc));
 	return 0;
 }
 
@@ -803,6 +812,12 @@ static int __hw_perf_event_init(struct perf_event *event)
 		goto out;
 	}
 
+	if (si.ribm & CPU_MF_SF_RIBM_NOTAV) {
+		pr_warn("CPU Measurement Facility sampling is temporarily not available\n");
+		err = -EBUSY;
+		goto out;
+	}
+
 	/* Always enable basic sampling */
 	SAMPL_FLAGS(hwc) = PERF_CPUM_SF_BASIC_MODE;
 
@@ -895,7 +910,7 @@ static int cpumsf_pmu_event_init(struct perf_event *event)
 
 	/* Check online status of the CPU to which the event is pinned */
 	if (event->cpu >= 0 && !cpu_online(event->cpu))
-			return -ENODEV;
+		return -ENODEV;
 
 	/* Force reset of idle/hv excludes regardless of what the
 	 * user requested.
@@ -943,8 +958,7 @@ static void cpumsf_pmu_enable(struct pmu *pmu)
 			 * buffer extents
 			 */
 			sfb_account_overflows(cpuhw, hwc);
-			if (sfb_has_pending_allocs(&cpuhw->sfb, hwc))
-				extend_sampling_buffer(&cpuhw->sfb, hwc);
+			extend_sampling_buffer(&cpuhw->sfb, hwc);
 		}
 		/* Rate may be adjusted with ioctl() */
 		cpuhw->lsctl.interval = SAMPL_RATE(&cpuhw->event->hw);
@@ -957,7 +971,7 @@ static void cpumsf_pmu_enable(struct pmu *pmu)
 	err = lsctl(&cpuhw->lsctl);
 	if (err) {
 		cpuhw->flags &= ~PMU_F_ENABLED;
-		pr_err("Loading sampling controls failed: op=%i err=%i\n",
+		pr_err("Loading sampling controls failed: op %i err %i\n",
 			1, err);
 		return;
 	}
@@ -965,12 +979,11 @@ static void cpumsf_pmu_enable(struct pmu *pmu)
 	/* Load current program parameter */
 	lpp(&S390_lowcore.lpp);
 
-	debug_sprintf_event(sfdbg, 6, "pmu_enable: es=%i cs=%i ed=%i cd=%i "
-			    "interval:%lx tear=%p dear=%p\n",
+	debug_sprintf_event(sfdbg, 6, "%s: es %i cs %i ed %i cd %i "
+			    "interval %#lx tear %#lx dear %#lx\n", __func__,
 			    cpuhw->lsctl.es, cpuhw->lsctl.cs, cpuhw->lsctl.ed,
 			    cpuhw->lsctl.cd, cpuhw->lsctl.interval,
-			    (void *) cpuhw->lsctl.tear,
-			    (void *) cpuhw->lsctl.dear);
+			    cpuhw->lsctl.tear, cpuhw->lsctl.dear);
 }
 
 static void cpumsf_pmu_disable(struct pmu *pmu)
@@ -993,13 +1006,14 @@ static void cpumsf_pmu_disable(struct pmu *pmu)
 
 	err = lsctl(&inactive);
 	if (err) {
-		pr_err("Loading sampling controls failed: op=%i err=%i\n",
+		pr_err("Loading sampling controls failed: op %i err %i\n",
 			2, err);
 		return;
 	}
 
 	/* Save state of TEAR and DEAR register contents */
-	if (!qsi(&si)) {
+	err = qsi(&si);
+	if (!err) {
 		/* TEAR/DEAR values are valid only if the sampling facility is
 		 * enabled.  Note that cpumsf_pmu_disable() might be called even
 		 * for a disabled sampling facility because cpumsf_pmu_enable()
@@ -1010,8 +1024,8 @@ static void cpumsf_pmu_disable(struct pmu *pmu)
 			cpuhw->lsctl.dear = si.dear;
 		}
 	} else
-		debug_sprintf_event(sfdbg, 3, "cpumsf_pmu_disable: "
-				    "qsi() failed with err=%i\n", err);
+		debug_sprintf_event(sfdbg, 3, "%s: qsi() failed with err %i\n",
+				    __func__, err);
 
 	cpuhw->flags &= ~PMU_F_ENABLED;
 }
@@ -1124,15 +1138,6 @@ static void perf_event_count_update(struct perf_event *event, u64 count)
 	local64_add(count, &event->count);
 }
 
-static void debug_sample_entry(struct hws_basic_entry *sample,
-			       struct hws_trailer_entry *te)
-{
-	debug_sprintf_event(sfdbg, 4, "hw_collect_samples: Found unknown "
-			    "sampling data entry: te->f=%i basic.def=%04x "
-			    "(%p)\n",
-			    te->f, sample->def, sample);
-}
-
 /* hw_collect_samples() - Walk through a sample-data-block and collect samples
  * @event:	The perf event
  * @sdbt:	Sample-data-block table
@@ -1186,7 +1191,11 @@ static void hw_collect_samples(struct perf_event *event, unsigned long *sdbt,
 				/* Count discarded samples */
 				*overflow += 1;
 		} else {
-			debug_sample_entry(sample, te);
+			debug_sprintf_event(sfdbg, 4,
+					    "%s: Found unknown"
+					    " sampling data entry: te->f %i"
+					    " basic.def %#4x (%p)\n", __func__,
+					    te->f, sample->def, sample);
 			/* Sample slot is not yet written or other record.
 			 *
 			 * This condition can occur if the buffer was reused
@@ -1261,9 +1270,9 @@ static void hw_perf_event_update(struct perf_event *event, int flush_all)
 			sampl_overflow += te->overflow;
 
 		/* Timestamps are valid for full sample-data-blocks only */
-		debug_sprintf_event(sfdbg, 6, "hw_perf_event_update: sdbt=%p "
-				    "overflow=%llu timestamp=%#llx\n",
-				    sdbt, te->overflow,
+		debug_sprintf_event(sfdbg, 6, "%s: sdbt %#lx "
+				    "overflow %llu timestamp %#llx\n",
+				    __func__, (unsigned long)sdbt, te->overflow,
 				    (te->f) ? trailer_timestamp(te) : 0ULL);
 
 		/* Collect all samples from a single sample-data-block and
@@ -1307,9 +1316,11 @@ static void hw_perf_event_update(struct perf_event *event, int flush_all)
 		OVERFLOW_REG(hwc) = DIV_ROUND_UP(OVERFLOW_REG(hwc) +
 						 sampl_overflow, 1 + num_sdb);
 	if (sampl_overflow || event_overflow)
-		debug_sprintf_event(sfdbg, 4, "hw_perf_event_update: "
-				    "overflow stats: sample=%llu event=%llu\n",
-				    sampl_overflow, event_overflow);
+		debug_sprintf_event(sfdbg, 4, "%s: "
+				    "overflows: sample %llu event %llu"
+				    " total %llu num_sdb %llu\n",
+				    __func__, sampl_overflow, event_overflow,
+				    OVERFLOW_REG(hwc), num_sdb);
 }
 
 #define AUX_SDB_INDEX(aux, i) ((i) % aux->sfb.num_sdb)
@@ -1362,7 +1373,7 @@ static void aux_output_end(struct perf_output_handle *handle)
 	te = aux_sdb_trailer(aux, aux->alert_mark);
 	te->flags &= ~SDB_TE_ALERT_REQ_MASK;
 
-	debug_sprintf_event(sfdbg, 6, "aux_output_end: collect %lx SDBs\n", i);
+	debug_sprintf_event(sfdbg, 6, "%s: collect %#lx SDBs\n", __func__, i);
 }
 
 /*
@@ -1420,10 +1431,10 @@ static int aux_output_begin(struct perf_output_handle *handle,
 	cpuhw->lsctl.tear = base + offset * sizeof(unsigned long);
 	cpuhw->lsctl.dear = aux->sdb_index[head];
 
-	debug_sprintf_event(sfdbg, 6, "aux_output_begin: "
+	debug_sprintf_event(sfdbg, 6, "%s: "
 			    "head->alert_mark->empty_mark (num_alert, range)"
-			    "[%lx -> %lx -> %lx] (%lx, %lx) "
-			    "tear index %lx, tear %lx dear %lx\n",
+			    "[%#lx -> %#lx -> %#lx] (%#lx, %#lx) "
+			    "tear index %#lx, tear %#lx dear %#lx\n", __func__,
 			    aux->head, aux->alert_mark, aux->empty_mark,
 			    AUX_SDB_NUM_ALERT(aux), range,
 			    head / CPUM_SF_SDB_PER_TABLE,
@@ -1567,7 +1578,9 @@ static void hw_collect_aux(struct cpu_hw_sf *cpuhw)
 			pr_err("The AUX buffer with %lu pages for the "
 			       "diagnostic-sampling mode is full\n",
 				num_sdb);
-			debug_sprintf_event(sfdbg, 1, "AUX buffer used up\n");
+			debug_sprintf_event(sfdbg, 1,
+					    "%s: AUX buffer used up\n",
+					    __func__);
 			break;
 		}
 		if (WARN_ON_ONCE(!aux))
@@ -1590,23 +1603,25 @@ static void hw_collect_aux(struct cpu_hw_sf *cpuhw)
 			perf_aux_output_end(&cpuhw->handle, size);
 			pr_err("Sample data caused the AUX buffer with %lu "
 			       "pages to overflow\n", num_sdb);
-			debug_sprintf_event(sfdbg, 1, "head %lx range %lx "
-					    "overflow %llx\n",
+			debug_sprintf_event(sfdbg, 1, "%s: head %#lx range %#lx "
+					    "overflow %#llx\n", __func__,
 					    aux->head, range, overflow);
 		} else {
 			size = AUX_SDB_NUM_ALERT(aux) << PAGE_SHIFT;
 			perf_aux_output_end(&cpuhw->handle, size);
-			debug_sprintf_event(sfdbg, 6, "head %lx alert %lx "
+			debug_sprintf_event(sfdbg, 6, "%s: head %#lx alert %#lx "
 					    "already full, try another\n",
+					    __func__,
 					    aux->head, aux->alert_mark);
 		}
 	}
 
 	if (done)
-		debug_sprintf_event(sfdbg, 6, "aux_reset_buffer: "
-				    "[%lx -> %lx -> %lx] (%lx, %lx)\n",
-				    aux->head, aux->alert_mark, aux->empty_mark,
-				    AUX_SDB_NUM_ALERT(aux), range);
+		debug_sprintf_event(sfdbg, 6, "%s: aux_reset_buffer "
+				    "[%#lx -> %#lx -> %#lx] (%#lx, %#lx)\n",
+				    __func__, aux->head, aux->alert_mark,
+				    aux->empty_mark, AUX_SDB_NUM_ALERT(aux),
+				    range);
 }
 
 /*
@@ -1629,8 +1644,8 @@ static void aux_buffer_free(void *data)
 	kfree(aux->sdb_index);
 	kfree(aux);
 
-	debug_sprintf_event(sfdbg, 4, "aux_buffer_free: free "
-			    "%lu SDBTs\n", num_sdbt);
+	debug_sprintf_event(sfdbg, 4, "%s: free "
+			    "%lu SDBTs\n", __func__, num_sdbt);
 }
 
 static void aux_sdb_init(unsigned long sdb)
@@ -1738,9 +1753,8 @@ static void *aux_buffer_setup(struct perf_event *event, void **pages,
 	 */
 	aux->empty_mark = sfb->num_sdb - 1;
 
-	debug_sprintf_event(sfdbg, 4, "aux_buffer_setup: setup %lu SDBTs"
-			    " and %lu SDBs\n",
-			    sfb->num_sdbt, sfb->num_sdb);
+	debug_sprintf_event(sfdbg, 4, "%s: setup %lu SDBTs and %lu SDBs\n",
+			    __func__, sfb->num_sdbt, sfb->num_sdb);
 
 	return aux;
 
@@ -1793,9 +1807,9 @@ static int cpumsf_pmu_check_period(struct perf_event *event, u64 value)
 	event->attr.sample_period = rate;
 	SAMPL_RATE(&event->hw) = rate;
 	hw_init_period(&event->hw, SAMPL_RATE(&event->hw));
-	debug_sprintf_event(sfdbg, 4, "cpumsf_pmu_check_period:"
-			    "cpu:%d value:%llx period:%llx freq:%d\n",
-			    event->cpu, value,
+	debug_sprintf_event(sfdbg, 4, "%s:"
+			    " cpu %d value %#llx period %#llx freq %d\n",
+			    __func__, event->cpu, value,
 			    event->attr.sample_period, do_freq);
 	return 0;
 }
@@ -1871,7 +1885,7 @@ static int cpumsf_pmu_add(struct perf_event *event, int flags)
 	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);
+		TEAR_REG(&event->hw) = (unsigned long) cpuhw->sfb.sdbt;
 	}
 
 	/* Ensure sampling functions are in the disabled state.  If disabled,
@@ -2026,7 +2040,7 @@ static void cpumf_measurement_alert(struct ext_code ext_code,
 
 	/* Report measurement alerts only for non-PRA codes */
 	if (alert != CPU_MF_INT_SF_PRA)
-		debug_sprintf_event(sfdbg, 6, "measurement alert: %#x\n",
+		debug_sprintf_event(sfdbg, 6, "%s: alert %#x\n", __func__,
 				    alert);
 
 	/* Sampling authorization change request */
@@ -2105,7 +2119,7 @@ static int param_set_sfb_size(const char *val, const struct kernel_param *kp)
 
 	sfb_set_limits(min, max);
 	pr_info("The sampling buffer limits have changed to: "
-		"min=%lu max=%lu (diag=x%lu)\n",
+		"min %lu max %lu (diag %lu)\n",
 		CPUM_SF_MIN_SDB, CPUM_SF_MAX_SDB, CPUM_SF_SDB_DIAG_FACTOR);
 	return 0;
 }
@@ -2123,7 +2137,7 @@ static const struct kernel_param_ops param_ops_sfb_size = {
 static void __init pr_cpumsf_err(unsigned int reason)
 {
 	pr_err("Sampling facility support for perf is not available: "
-	       "reason=%04x\n", reason);
+	       "reason %#x\n", reason);
 }
 
 static int __init init_cpum_sampling_pmu(void)