PMU driver can advertise certain feature via capability attribute('caps'
sysfs directory) which can be consumed by userspace tools like perf. Add
zen4_ibs_extensions capability attribute for IBS pmus. This attribute
will be enabled when CPUID_Fn8000001B_EAX[11] is set.
Without patch:
$ ls /sys/bus/event_source/devices/ibs_op/caps
ls: cannot access '/sys/.../ibs_op/caps': No such file or directory
With patch:
$ ls /sys/bus/event_source/devices/ibs_op/caps
zen4_ibs_extensions
Signed-off-by: Ravi Bangoria <[email protected]>
---
arch/x86/events/amd/ibs.c | 34 ++++++++++++++++++++++++++++------
1 file changed, 28 insertions(+), 6 deletions(-)
diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
index a5303d62060c..54e12bd7843e 100644
--- a/arch/x86/events/amd/ibs.c
+++ b/arch/x86/events/amd/ibs.c
@@ -95,8 +95,10 @@ struct perf_ibs {
struct cpu_perf_ibs __percpu *pcpu;
struct attribute **format_attrs;
+ struct attribute **caps_attrs;
struct attribute_group format_group;
- const struct attribute_group *attr_groups[2];
+ struct attribute_group caps_group;
+ const struct attribute_group *attr_groups[3];
u64 (*get_count)(u64 config);
};
@@ -522,10 +524,13 @@ PMU_FORMAT_ATTR(rand_en, "config:57");
PMU_FORMAT_ATTR(cnt_ctl, "config:19");
PMU_EVENT_ATTR_STRING(l3missonly, fetch_l3missonly, "config:59");
PMU_EVENT_ATTR_STRING(l3missonly, op_l3missonly, "config:16");
+PMU_EVENT_ATTR_STRING(zen4_ibs_extensions, zen4_ibs_extensions, "1");
/* size = nr attrs plus NULL at the end */
static struct attribute *ibs_fetch_format_attrs[3];
static struct attribute *ibs_op_format_attrs[3];
+static struct attribute *ibs_fetch_caps_attrs[2];
+static struct attribute *ibs_op_caps_attrs[2];
static struct perf_ibs perf_ibs_fetch = {
.pmu = {
@@ -548,6 +553,7 @@ static struct perf_ibs perf_ibs_fetch = {
.offset_mask = { MSR_AMD64_IBSFETCH_REG_MASK },
.offset_max = MSR_AMD64_IBSFETCH_REG_COUNT,
.format_attrs = ibs_fetch_format_attrs,
+ .caps_attrs = ibs_fetch_caps_attrs,
.get_count = get_ibs_fetch_count,
};
@@ -574,6 +580,7 @@ static struct perf_ibs perf_ibs_op = {
.offset_mask = { MSR_AMD64_IBSOP_REG_MASK },
.offset_max = MSR_AMD64_IBSOP_REG_COUNT,
.format_attrs = ibs_op_format_attrs,
+ .caps_attrs = ibs_op_caps_attrs,
.get_count = get_ibs_op_count,
};
@@ -728,6 +735,7 @@ static __init int perf_ibs_pmu_init(struct perf_ibs *perf_ibs, char *name)
{
struct cpu_perf_ibs __percpu *pcpu;
int ret;
+ int i = 0;
pcpu = alloc_percpu(struct cpu_perf_ibs);
if (!pcpu)
@@ -736,16 +744,26 @@ static __init int perf_ibs_pmu_init(struct perf_ibs *perf_ibs, char *name)
perf_ibs->pcpu = pcpu;
/* register attributes */
+ memset(&perf_ibs->attr_groups, 0, sizeof(perf_ibs->attr_groups));
if (perf_ibs->format_attrs[0]) {
memset(&perf_ibs->format_group, 0, sizeof(perf_ibs->format_group));
- perf_ibs->format_group.name = "format";
- perf_ibs->format_group.attrs = perf_ibs->format_attrs;
+ perf_ibs->format_group.name = "format";
+ perf_ibs->format_group.attrs = perf_ibs->format_attrs;
- memset(&perf_ibs->attr_groups, 0, sizeof(perf_ibs->attr_groups));
- perf_ibs->attr_groups[0] = &perf_ibs->format_group;
- perf_ibs->pmu.attr_groups = perf_ibs->attr_groups;
+ perf_ibs->attr_groups[i++] = &perf_ibs->format_group;
}
+ if (perf_ibs->caps_attrs[0]) {
+ memset(&perf_ibs->caps_group, 0, sizeof(perf_ibs->caps_group));
+ perf_ibs->caps_group.name = "caps";
+ perf_ibs->caps_group.attrs = perf_ibs->caps_attrs;
+
+ perf_ibs->attr_groups[i++] = &perf_ibs->caps_group;
+ }
+
+ if (i)
+ perf_ibs->pmu.attr_groups = perf_ibs->attr_groups;
+
ret = perf_pmu_register(&perf_ibs->pmu, name, -1);
if (ret) {
perf_ibs->pcpu = NULL;
@@ -758,6 +776,7 @@ static __init int perf_ibs_pmu_init(struct perf_ibs *perf_ibs, char *name)
static __init void perf_ibs_fetch_prepare(void)
{
struct attribute **format_attrs = perf_ibs_fetch.format_attrs;
+ struct attribute **caps_attr = perf_ibs_fetch.caps_attrs;
/*
* Some chips fail to reset the fetch count when it is written; instead
@@ -773,6 +792,7 @@ static __init void perf_ibs_fetch_prepare(void)
if (ibs_caps & IBS_CAPS_ZEN4IBSEXTENSIONS) {
perf_ibs_fetch.config_mask |= IBS_FETCH_L3MISSONLY;
*format_attrs++ = &fetch_l3missonly.attr.attr;
+ *caps_attr++ = &zen4_ibs_extensions.attr.attr;
}
perf_ibs_pmu_init(&perf_ibs_fetch, "ibs_fetch");
@@ -781,6 +801,7 @@ static __init void perf_ibs_fetch_prepare(void)
static __init void perf_ibs_op_prepare(void)
{
struct attribute **format_attrs = perf_ibs_op.format_attrs;
+ struct attribute **caps_attr = perf_ibs_op.caps_attrs;
if (ibs_caps & IBS_CAPS_OPCNT) {
perf_ibs_op.config_mask |= IBS_OP_CNT_CTL;
@@ -796,6 +817,7 @@ static __init void perf_ibs_op_prepare(void)
if (ibs_caps & IBS_CAPS_ZEN4IBSEXTENSIONS) {
perf_ibs_op.config_mask |= IBS_OP_L3MISSONLY;
*format_attrs++ = &op_l3missonly.attr.attr;
+ *caps_attr++ = &zen4_ibs_extensions.attr.attr;
}
perf_ibs_pmu_init(&perf_ibs_op, "ibs_op");
--
2.27.0
On 25.04.22 10:13:19, Ravi Bangoria wrote:
> PMU driver can advertise certain feature via capability attribute('caps'
> sysfs directory) which can be consumed by userspace tools like perf. Add
> zen4_ibs_extensions capability attribute for IBS pmus. This attribute
> will be enabled when CPUID_Fn8000001B_EAX[11] is set.
>
> Without patch:
>
> $ ls /sys/bus/event_source/devices/ibs_op/caps
> ls: cannot access '/sys/.../ibs_op/caps': No such file or directory
>
> With patch:
>
> $ ls /sys/bus/event_source/devices/ibs_op/caps
> zen4_ibs_extensions
>
> Signed-off-by: Ravi Bangoria <[email protected]>
> ---
> arch/x86/events/amd/ibs.c | 34 ++++++++++++++++++++++++++++------
> 1 file changed, 28 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
> index a5303d62060c..54e12bd7843e 100644
> --- a/arch/x86/events/amd/ibs.c
> +++ b/arch/x86/events/amd/ibs.c
> @@ -95,8 +95,10 @@ struct perf_ibs {
> struct cpu_perf_ibs __percpu *pcpu;
>
> struct attribute **format_attrs;
> + struct attribute **caps_attrs;
> struct attribute_group format_group;
> - const struct attribute_group *attr_groups[2];
> + struct attribute_group caps_group;
> + const struct attribute_group *attr_groups[3];
Also add a macro for max groups.
>
> u64 (*get_count)(u64 config);
> };
> @@ -522,10 +524,13 @@ PMU_FORMAT_ATTR(rand_en, "config:57");
> PMU_FORMAT_ATTR(cnt_ctl, "config:19");
> PMU_EVENT_ATTR_STRING(l3missonly, fetch_l3missonly, "config:59");
> PMU_EVENT_ATTR_STRING(l3missonly, op_l3missonly, "config:16");
> +PMU_EVENT_ATTR_STRING(zen4_ibs_extensions, zen4_ibs_extensions, "1");
>
> /* size = nr attrs plus NULL at the end */
> static struct attribute *ibs_fetch_format_attrs[3];
> static struct attribute *ibs_op_format_attrs[3];
> +static struct attribute *ibs_fetch_caps_attrs[2];
> +static struct attribute *ibs_op_caps_attrs[2];
>
> static struct perf_ibs perf_ibs_fetch = {
> .pmu = {
> @@ -548,6 +553,7 @@ static struct perf_ibs perf_ibs_fetch = {
> .offset_mask = { MSR_AMD64_IBSFETCH_REG_MASK },
> .offset_max = MSR_AMD64_IBSFETCH_REG_COUNT,
> .format_attrs = ibs_fetch_format_attrs,
> + .caps_attrs = ibs_fetch_caps_attrs,
>
> .get_count = get_ibs_fetch_count,
> };
> @@ -574,6 +580,7 @@ static struct perf_ibs perf_ibs_op = {
> .offset_mask = { MSR_AMD64_IBSOP_REG_MASK },
> .offset_max = MSR_AMD64_IBSOP_REG_COUNT,
> .format_attrs = ibs_op_format_attrs,
> + .caps_attrs = ibs_op_caps_attrs,
>
> .get_count = get_ibs_op_count,
> };
> @@ -728,6 +735,7 @@ static __init int perf_ibs_pmu_init(struct perf_ibs *perf_ibs, char *name)
> {
> struct cpu_perf_ibs __percpu *pcpu;
> int ret;
> + int i = 0;
'group'? Use a pointer to iterate over groups here same as for attrs?
struct attribute_group **group = &perf_ibs->attr_groups;
>
> pcpu = alloc_percpu(struct cpu_perf_ibs);
> if (!pcpu)
> @@ -736,16 +744,26 @@ static __init int perf_ibs_pmu_init(struct perf_ibs *perf_ibs, char *name)
> perf_ibs->pcpu = pcpu;
>
> /* register attributes */
> + memset(&perf_ibs->attr_groups, 0, sizeof(perf_ibs->attr_groups));
With a termination below this could be dropped.
> if (perf_ibs->format_attrs[0]) {
> memset(&perf_ibs->format_group, 0, sizeof(perf_ibs->format_group));
> - perf_ibs->format_group.name = "format";
> - perf_ibs->format_group.attrs = perf_ibs->format_attrs;
> + perf_ibs->format_group.name = "format";
> + perf_ibs->format_group.attrs = perf_ibs->format_attrs;
>
> - memset(&perf_ibs->attr_groups, 0, sizeof(perf_ibs->attr_groups));
> - perf_ibs->attr_groups[0] = &perf_ibs->format_group;
> - perf_ibs->pmu.attr_groups = perf_ibs->attr_groups;
> + perf_ibs->attr_groups[i++] = &perf_ibs->format_group;
So this could be:
*groups++ = &perf_ibs->format_group
> }
>
> + if (perf_ibs->caps_attrs[0]) {
> + memset(&perf_ibs->caps_group, 0, sizeof(perf_ibs->caps_group));
> + perf_ibs->caps_group.name = "caps";
> + perf_ibs->caps_group.attrs = perf_ibs->caps_attrs;
> +
> + perf_ibs->attr_groups[i++] = &perf_ibs->caps_group;
Similar here.
> + }
Add a terminating NULL pointer for groups here.
> +
> + if (i)
if (perf_ibs->attr_groups[0])
...
> + perf_ibs->pmu.attr_groups = perf_ibs->attr_groups;
> +
> ret = perf_pmu_register(&perf_ibs->pmu, name, -1);
> if (ret) {
> perf_ibs->pcpu = NULL;
> @@ -758,6 +776,7 @@ static __init int perf_ibs_pmu_init(struct perf_ibs *perf_ibs, char *name)
> static __init void perf_ibs_fetch_prepare(void)
> {
> struct attribute **format_attrs = perf_ibs_fetch.format_attrs;
> + struct attribute **caps_attr = perf_ibs_fetch.caps_attrs;
Now I see why it was renamed, ok.
>
> /*
> * Some chips fail to reset the fetch count when it is written; instead
> @@ -773,6 +792,7 @@ static __init void perf_ibs_fetch_prepare(void)
> if (ibs_caps & IBS_CAPS_ZEN4IBSEXTENSIONS) {
> perf_ibs_fetch.config_mask |= IBS_FETCH_L3MISSONLY;
> *format_attrs++ = &fetch_l3missonly.attr.attr;
> + *caps_attr++ = &zen4_ibs_extensions.attr.attr;
> }
>
> perf_ibs_pmu_init(&perf_ibs_fetch, "ibs_fetch");
> @@ -781,6 +801,7 @@ static __init void perf_ibs_fetch_prepare(void)
> static __init void perf_ibs_op_prepare(void)
> {
> struct attribute **format_attrs = perf_ibs_op.format_attrs;
> + struct attribute **caps_attr = perf_ibs_op.caps_attrs;
>
> if (ibs_caps & IBS_CAPS_OPCNT) {
> perf_ibs_op.config_mask |= IBS_OP_CNT_CTL;
> @@ -796,6 +817,7 @@ static __init void perf_ibs_op_prepare(void)
> if (ibs_caps & IBS_CAPS_ZEN4IBSEXTENSIONS) {
> perf_ibs_op.config_mask |= IBS_OP_L3MISSONLY;
> *format_attrs++ = &op_l3missonly.attr.attr;
> + *caps_attr++ = &zen4_ibs_extensions.attr.attr;
> }
Also add a termination for caps here.
-Robert
>
> perf_ibs_pmu_init(&perf_ibs_op, "ibs_op");
> --
> 2.27.0
>
On 26-Apr-22 3:27 PM, Robert Richter wrote:
> On 25.04.22 10:13:19, Ravi Bangoria wrote:
>> PMU driver can advertise certain feature via capability attribute('caps'
>> sysfs directory) which can be consumed by userspace tools like perf. Add
>> zen4_ibs_extensions capability attribute for IBS pmus. This attribute
>> will be enabled when CPUID_Fn8000001B_EAX[11] is set.
>>
>> Without patch:
>>
>> $ ls /sys/bus/event_source/devices/ibs_op/caps
>> ls: cannot access '/sys/.../ibs_op/caps': No such file or directory
>>
>> With patch:
>>
>> $ ls /sys/bus/event_source/devices/ibs_op/caps
>> zen4_ibs_extensions
>>
>> Signed-off-by: Ravi Bangoria <[email protected]>
>> ---
>> arch/x86/events/amd/ibs.c | 34 ++++++++++++++++++++++++++++------
>> 1 file changed, 28 insertions(+), 6 deletions(-)
>>
>> diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
>> index a5303d62060c..54e12bd7843e 100644
>> --- a/arch/x86/events/amd/ibs.c
>> +++ b/arch/x86/events/amd/ibs.c
>> @@ -95,8 +95,10 @@ struct perf_ibs {
>> struct cpu_perf_ibs __percpu *pcpu;
>>
>> struct attribute **format_attrs;
>> + struct attribute **caps_attrs;
>> struct attribute_group format_group;
>> - const struct attribute_group *attr_groups[2];
>> + struct attribute_group caps_group;
>> + const struct attribute_group *attr_groups[3];
>
> Also add a macro for max groups.
Same as previous patch, except defining size of the array, it won't
be used anywhere else.
>
>>
>> u64 (*get_count)(u64 config);
>> };
>> @@ -522,10 +524,13 @@ PMU_FORMAT_ATTR(rand_en, "config:57");
>> PMU_FORMAT_ATTR(cnt_ctl, "config:19");
>> PMU_EVENT_ATTR_STRING(l3missonly, fetch_l3missonly, "config:59");
>> PMU_EVENT_ATTR_STRING(l3missonly, op_l3missonly, "config:16");
>> +PMU_EVENT_ATTR_STRING(zen4_ibs_extensions, zen4_ibs_extensions, "1");
>>
>> /* size = nr attrs plus NULL at the end */
>> static struct attribute *ibs_fetch_format_attrs[3];
>> static struct attribute *ibs_op_format_attrs[3];
>> +static struct attribute *ibs_fetch_caps_attrs[2];
>> +static struct attribute *ibs_op_caps_attrs[2];
>>
>> static struct perf_ibs perf_ibs_fetch = {
>> .pmu = {
>> @@ -548,6 +553,7 @@ static struct perf_ibs perf_ibs_fetch = {
>> .offset_mask = { MSR_AMD64_IBSFETCH_REG_MASK },
>> .offset_max = MSR_AMD64_IBSFETCH_REG_COUNT,
>> .format_attrs = ibs_fetch_format_attrs,
>> + .caps_attrs = ibs_fetch_caps_attrs,
>>
>> .get_count = get_ibs_fetch_count,
>> };
>> @@ -574,6 +580,7 @@ static struct perf_ibs perf_ibs_op = {
>> .offset_mask = { MSR_AMD64_IBSOP_REG_MASK },
>> .offset_max = MSR_AMD64_IBSOP_REG_COUNT,
>> .format_attrs = ibs_op_format_attrs,
>> + .caps_attrs = ibs_op_caps_attrs,
>>
>> .get_count = get_ibs_op_count,
>> };
>> @@ -728,6 +735,7 @@ static __init int perf_ibs_pmu_init(struct perf_ibs *perf_ibs, char *name)
>> {
>> struct cpu_perf_ibs __percpu *pcpu;
>> int ret;
>> + int i = 0;
>
> 'group'? Use a pointer to iterate over groups here same as for attrs?
>
> struct attribute_group **group = &perf_ibs->attr_groups;
Sure.
>
>>
>> pcpu = alloc_percpu(struct cpu_perf_ibs);
>> if (!pcpu)
>> @@ -736,16 +744,26 @@ static __init int perf_ibs_pmu_init(struct perf_ibs *perf_ibs, char *name)
>> perf_ibs->pcpu = pcpu;
>>
>> /* register attributes */
>> + memset(&perf_ibs->attr_groups, 0, sizeof(perf_ibs->attr_groups));
>
> With a termination below this could be dropped.
I think we can just remove this line. perf_ibs points to either perf_ibs_fetch
or perf_ibs_op, both of which are global variables and would be preinitialized
with 0s.
>
>> if (perf_ibs->format_attrs[0]) {
>> memset(&perf_ibs->format_group, 0, sizeof(perf_ibs->format_group));
>> - perf_ibs->format_group.name = "format";
>> - perf_ibs->format_group.attrs = perf_ibs->format_attrs;
>> + perf_ibs->format_group.name = "format";
>> + perf_ibs->format_group.attrs = perf_ibs->format_attrs;
>>
>> - memset(&perf_ibs->attr_groups, 0, sizeof(perf_ibs->attr_groups));
>> - perf_ibs->attr_groups[0] = &perf_ibs->format_group;
>> - perf_ibs->pmu.attr_groups = perf_ibs->attr_groups;
>> + perf_ibs->attr_groups[i++] = &perf_ibs->format_group;
>
> So this could be:
>
> *groups++ = &perf_ibs->format_group
>
>> }
>>
>> + if (perf_ibs->caps_attrs[0]) {
>> + memset(&perf_ibs->caps_group, 0, sizeof(perf_ibs->caps_group));
>> + perf_ibs->caps_group.name = "caps";
>> + perf_ibs->caps_group.attrs = perf_ibs->caps_attrs;
>> +
>> + perf_ibs->attr_groups[i++] = &perf_ibs->caps_group;
>
> Similar here.
>
>> + }
>
> Add a terminating NULL pointer for groups here.
>
>> +
>> + if (i)
>
> if (perf_ibs->attr_groups[0])
> ...
>
>> + perf_ibs->pmu.attr_groups = perf_ibs->attr_groups;
>> +
>> ret = perf_pmu_register(&perf_ibs->pmu, name, -1);
>> if (ret) {
>> perf_ibs->pcpu = NULL;
>> @@ -758,6 +776,7 @@ static __init int perf_ibs_pmu_init(struct perf_ibs *perf_ibs, char *name)
>> static __init void perf_ibs_fetch_prepare(void)
>> {
>> struct attribute **format_attrs = perf_ibs_fetch.format_attrs;
>> + struct attribute **caps_attr = perf_ibs_fetch.caps_attrs;
>
> Now I see why it was renamed, ok.
Yup.
Thanks for the review,
Ravi