[PATCH] powerpc/perf: Add support for programming of Thresholding in P10
Kajol Jain
kjain at linux.ibm.com
Wed Oct 14 19:44:42 AEDT 2020
Thresholding, a performance monitoring unit feature, can be
used to identify marked instructions which take more than
expected cycles between start event and end event.
Threshold compare (thresh_cmp) bits are programmed in MMCRA
register. In Power9, thresh_cmp bits were part of the
event code. But in case of P10, thresh_cmp are not part of
event code due to inclusion of MMCR3 bits.
Patch here adds an option to use attr.config1 variable
to be used to pass thresh_cmp value to be programmed in
MMCRA register. A new ppmu flag called PPMU_HAS_ATTR_CONFIG1
has been added and this flag is used to notify the use of
attr.config1 variable. Secondly, thresh_cmp bits are not
part of the group constraints.
Patch has extended the parameter list of 'compute_mmcr',
to include power_pmu's 'flags' element.
command#: cat /sys/devices/cpu/format/thresh_cmp
config1:0-17
ex. usage:
command#: perf record -I --weight -d -e
cpu/event=0x67340101EC,thresh_cmp=500/ ./ebizzy -S 2 -t 1 -s 4096
1826636 records/s
real 2.00 s
user 2.00 s
sys 0.00 s
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.038 MB perf.data (61 samples) ]
Signed-off-by: Kajol Jain<kjain at linux.ibm.com>
---
arch/powerpc/include/asm/perf_event_server.h | 4 +-
arch/powerpc/perf/core-book3s.c | 2 +-
arch/powerpc/perf/isa207-common.c | 54 ++++++++++++++++++--
arch/powerpc/perf/isa207-common.h | 6 ++-
arch/powerpc/perf/mpc7450-pmu.c | 3 +-
arch/powerpc/perf/power10-pmu.c | 4 +-
arch/powerpc/perf/power5+-pmu.c | 3 +-
arch/powerpc/perf/power5-pmu.c | 3 +-
arch/powerpc/perf/power6-pmu.c | 3 +-
arch/powerpc/perf/power7-pmu.c | 3 +-
arch/powerpc/perf/ppc970-pmu.c | 3 +-
11 files changed, 73 insertions(+), 15 deletions(-)
diff --git a/arch/powerpc/include/asm/perf_event_server.h b/arch/powerpc/include/asm/perf_event_server.h
index f6acabb6c9be..566e41d4ff6a 100644
--- a/arch/powerpc/include/asm/perf_event_server.h
+++ b/arch/powerpc/include/asm/perf_event_server.h
@@ -34,9 +34,10 @@ struct power_pmu {
int max_alternatives;
unsigned long add_fields;
unsigned long test_adder;
+ /* TODO: parameter list is growing and should consider folding all this to a struct */
int (*compute_mmcr)(u64 events[], int n_ev,
unsigned int hwc[], struct mmcr_regs *mmcr,
- struct perf_event *pevents[]);
+ struct perf_event *pevents[], u32 flags);
int (*get_constraint)(u64 event_id, unsigned long *mskp,
unsigned long *valp);
int (*get_alternatives)(u64 event_id, unsigned int flags,
@@ -82,6 +83,7 @@ struct power_pmu {
#define PPMU_ARCH_207S 0x00000080 /* PMC is architecture v2.07S */
#define PPMU_NO_SIAR 0x00000100 /* Do not use SIAR */
#define PPMU_ARCH_31 0x00000200 /* Has MMCR3, SIER2 and SIER3 */
+#define PPMU_HAS_ATTR_CONFIG1 0x00000400 /* Using config1 attribute */
/*
* Values for flags to get_alternatives()
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index 08643cba1494..e4c817f64566 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -1356,7 +1356,7 @@ static void power_pmu_enable(struct pmu *pmu)
memset(&cpuhw->mmcr, 0, sizeof(cpuhw->mmcr));
if (ppmu->compute_mmcr(cpuhw->events, cpuhw->n_events, hwc_index,
- &cpuhw->mmcr, cpuhw->event)) {
+ &cpuhw->mmcr, cpuhw->event, ppmu->flags)) {
/* shouldn't ever get here */
printk(KERN_ERR "oops compute_mmcr failed\n");
goto out;
diff --git a/arch/powerpc/perf/isa207-common.c b/arch/powerpc/perf/isa207-common.c
index 964437adec18..cfad88b7ca85 100644
--- a/arch/powerpc/perf/isa207-common.c
+++ b/arch/powerpc/perf/isa207-common.c
@@ -110,10 +110,48 @@ static void mmcra_sdar_mode(u64 event, unsigned long *mmcra)
static u64 thresh_cmp_val(u64 value)
{
- if (cpu_has_feature(CPU_FTR_ARCH_300))
- return value << p9_MMCRA_THR_CMP_SHIFT;
+ int exp = 0;
+ u64 result = value;
+
+ if (!value)
+ return value;
+
+ /*
+ * Incase of P10, thresh_cmp value is not part of raw event code
+ * and provided via attr.config1 parameter. To program threshold in MMCRA,
+ * take a 18 bit number N and shift right 2 places and increment
+ * the exponent E by 1 until the upper 10 bits of N are zero.
+ * Write E to the threshold exponent and write the lower 8 bits of N
+ * to the threshold mantissa.
+ * The max threshold that can be written is 261120.
+ */
+ if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+ if (value > 261120)
+ value = 261120;
+ while ((64 - __builtin_clzl(value)) > 8) {
+ exp++;
+ value >>= 2;
+ }
+
+ /*
+ * Note that it is invalid to write a mantissa with the
+ * upper 2 bits of mantissa being zero, unless the
+ * exponent is also zero.
+ */
+ if (!(value & 0xC0) && exp)
+ result = 0;
+ else
+ result = (exp << 8) | value;
+ }
- return value << MMCRA_THR_CMP_SHIFT;
+ /*
+ * Since location of threshold compare bits in MMCRA
+ * is different for p8, using different shift value.
+ */
+ if (cpu_has_feature(CPU_FTR_ARCH_300))
+ return result << p9_MMCRA_THR_CMP_SHIFT;
+ else
+ return result << MMCRA_THR_CMP_SHIFT;
}
static unsigned long combine_from_event(u64 event)
@@ -144,7 +182,9 @@ static bool is_thresh_cmp_valid(u64 event)
/*
* Check the mantissa upper two bits are not zero, unless the
* exponent is also zero. See the THRESH_CMP_MANTISSA doc.
- * Power10: thresh_cmp is replaced by l2_l3 event select.
+ * Power10: thresh_cmp bits are not part of raw event code.
+ * attr.config1 is used to get thresh_cmp value from user.
+ * And hence thresh_cmp is not part of group constraint.
*/
if (cpu_has_feature(CPU_FTR_ARCH_31))
return false;
@@ -386,7 +426,7 @@ int isa207_get_constraint(u64 event, unsigned long *maskp, unsigned long *valp)
int isa207_compute_mmcr(u64 event[], int n_ev,
unsigned int hwc[], struct mmcr_regs *mmcr,
- struct perf_event *pevents[])
+ struct perf_event *pevents[], u32 flags)
{
unsigned long mmcra, mmcr1, mmcr2, unit, combine, psel, cache, val;
unsigned long mmcr3;
@@ -472,6 +512,10 @@ int isa207_compute_mmcr(u64 event[], int n_ev,
val = (event[i] >> EVENT_THR_CMP_SHIFT) &
EVENT_THR_CMP_MASK;
mmcra |= thresh_cmp_val(val);
+ } else if (flags & PPMU_HAS_ATTR_CONFIG1) {
+ val = (pevents[i]->attr.config1 >> p10_EVENT_THR_CMP_SHIFT) &
+ p10_EVENT_THR_CMP_MASK;
+ mmcra |= thresh_cmp_val(val);
}
}
diff --git a/arch/powerpc/perf/isa207-common.h b/arch/powerpc/perf/isa207-common.h
index 044de65e96b9..8d365dccce50 100644
--- a/arch/powerpc/perf/isa207-common.h
+++ b/arch/powerpc/perf/isa207-common.h
@@ -100,6 +100,10 @@
#define p10_EVENT_MMCR3_MASK 0x7fffull
#define p10_EVENT_MMCR3_SHIFT 45
+/* Event Threshold Compare bit constant for power10 in config1 attribute */
+#define p10_EVENT_THR_CMP_SHIFT 0
+#define p10_EVENT_THR_CMP_MASK 0x3FFFFull
+
#define p10_EVENT_VALID_MASK \
((p10_SDAR_MODE_MASK << p10_SDAR_MODE_SHIFT | \
(p10_EVENT_THRESH_MASK << EVENT_THRESH_SHIFT) | \
@@ -249,7 +253,7 @@
int isa207_get_constraint(u64 event, unsigned long *maskp, unsigned long *valp);
int isa207_compute_mmcr(u64 event[], int n_ev,
unsigned int hwc[], struct mmcr_regs *mmcr,
- struct perf_event *pevents[]);
+ struct perf_event *pevents[], u32 flags);
void isa207_disable_pmc(unsigned int pmc, struct mmcr_regs *mmcr);
int isa207_get_alternatives(u64 event, u64 alt[], int size, unsigned int flags,
const unsigned int ev_alt[][MAX_ALT]);
diff --git a/arch/powerpc/perf/mpc7450-pmu.c b/arch/powerpc/perf/mpc7450-pmu.c
index 1919e9df9165..50612b1fafb9 100644
--- a/arch/powerpc/perf/mpc7450-pmu.c
+++ b/arch/powerpc/perf/mpc7450-pmu.c
@@ -258,7 +258,8 @@ static const u32 pmcsel_mask[N_COUNTER] = {
*/
static int mpc7450_compute_mmcr(u64 event[], int n_ev, unsigned int hwc[],
struct mmcr_regs *mmcr,
- struct perf_event *pevents[])
+ struct perf_event *pevents[],
+ u32 flags __maybe_unused)
{
u8 event_index[N_CLASSES][N_COUNTER];
int n_classevent[N_CLASSES];
diff --git a/arch/powerpc/perf/power10-pmu.c b/arch/powerpc/perf/power10-pmu.c
index 83148656b524..a838da409570 100644
--- a/arch/powerpc/perf/power10-pmu.c
+++ b/arch/powerpc/perf/power10-pmu.c
@@ -176,6 +176,7 @@ PMU_FORMAT_ATTR(src_sel, "config:45-46");
PMU_FORMAT_ATTR(invert_bit, "config:47");
PMU_FORMAT_ATTR(src_mask, "config:48-53");
PMU_FORMAT_ATTR(src_match, "config:54-59");
+PMU_FORMAT_ATTR(thresh_cmp, "config1:0-17");
static struct attribute *power10_pmu_format_attr[] = {
&format_attr_event.attr,
@@ -195,6 +196,7 @@ static struct attribute *power10_pmu_format_attr[] = {
&format_attr_invert_bit.attr,
&format_attr_src_mask.attr,
&format_attr_src_match.attr,
+ &format_attr_thresh_cmp.attr,
NULL,
};
@@ -393,7 +395,7 @@ static struct power_pmu power10_pmu = {
.get_mem_weight = isa207_get_mem_weight,
.disable_pmc = isa207_disable_pmc,
.flags = PPMU_HAS_SIER | PPMU_ARCH_207S |
- PPMU_ARCH_31,
+ PPMU_ARCH_31 | PPMU_HAS_ATTR_CONFIG1,
.n_generic = ARRAY_SIZE(power10_generic_events),
.generic_events = power10_generic_events,
.cache_events = &power10_cache_events,
diff --git a/arch/powerpc/perf/power5+-pmu.c b/arch/powerpc/perf/power5+-pmu.c
index a62b2cd7914f..6eeeb4df523d 100644
--- a/arch/powerpc/perf/power5+-pmu.c
+++ b/arch/powerpc/perf/power5+-pmu.c
@@ -449,7 +449,8 @@ static int power5p_marked_instr_event(u64 event)
static int power5p_compute_mmcr(u64 event[], int n_ev,
unsigned int hwc[], struct mmcr_regs *mmcr,
- struct perf_event *pevents[])
+ struct perf_event *pevents[],
+ u32 flags __maybe_unused)
{
unsigned long mmcr1 = 0;
unsigned long mmcra = 0;
diff --git a/arch/powerpc/perf/power5-pmu.c b/arch/powerpc/perf/power5-pmu.c
index 8732b587cf71..190973b2d394 100644
--- a/arch/powerpc/perf/power5-pmu.c
+++ b/arch/powerpc/perf/power5-pmu.c
@@ -380,7 +380,8 @@ static int power5_marked_instr_event(u64 event)
static int power5_compute_mmcr(u64 event[], int n_ev,
unsigned int hwc[], struct mmcr_regs *mmcr,
- struct perf_event *pevents[])
+ struct perf_event *pevents[],
+ u32 flags __maybe_unused)
{
unsigned long mmcr1 = 0;
unsigned long mmcra = MMCRA_SDAR_DCACHE_MISS | MMCRA_SDAR_ERAT_MISS;
diff --git a/arch/powerpc/perf/power6-pmu.c b/arch/powerpc/perf/power6-pmu.c
index 0e318cf87129..579606315b4d 100644
--- a/arch/powerpc/perf/power6-pmu.c
+++ b/arch/powerpc/perf/power6-pmu.c
@@ -171,7 +171,8 @@ static int power6_marked_instr_event(u64 event)
* Assign PMC numbers and compute MMCR1 value for a set of events
*/
static int p6_compute_mmcr(u64 event[], int n_ev,
- unsigned int hwc[], struct mmcr_regs *mmcr, struct perf_event *pevents[])
+ unsigned int hwc[], struct mmcr_regs *mmcr, struct perf_event *pevents[],
+ u32 flags __maybe_unused)
{
unsigned long mmcr1 = 0;
unsigned long mmcra = MMCRA_SDAR_DCACHE_MISS | MMCRA_SDAR_ERAT_MISS;
diff --git a/arch/powerpc/perf/power7-pmu.c b/arch/powerpc/perf/power7-pmu.c
index 5e0bf09cf077..a929917f7259 100644
--- a/arch/powerpc/perf/power7-pmu.c
+++ b/arch/powerpc/perf/power7-pmu.c
@@ -243,7 +243,8 @@ static int power7_marked_instr_event(u64 event)
static int power7_compute_mmcr(u64 event[], int n_ev,
unsigned int hwc[], struct mmcr_regs *mmcr,
- struct perf_event *pevents[])
+ struct perf_event *pevents[],
+ u32 flags __maybe_unused)
{
unsigned long mmcr1 = 0;
unsigned long mmcra = MMCRA_SDAR_DCACHE_MISS | MMCRA_SDAR_ERAT_MISS;
diff --git a/arch/powerpc/perf/ppc970-pmu.c b/arch/powerpc/perf/ppc970-pmu.c
index d35223fb112c..4a0b1eeab643 100644
--- a/arch/powerpc/perf/ppc970-pmu.c
+++ b/arch/powerpc/perf/ppc970-pmu.c
@@ -254,7 +254,8 @@ static int p970_get_alternatives(u64 event, unsigned int flags, u64 alt[])
static int p970_compute_mmcr(u64 event[], int n_ev,
unsigned int hwc[], struct mmcr_regs *mmcr,
- struct perf_event *pevents[])
+ struct perf_event *pevents[],
+ u32 flags __maybe_unused)
{
unsigned long mmcr0 = 0, mmcr1 = 0, mmcra = 0;
unsigned int pmc, unit, byte, psel;
--
2.26.2
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