2022-06-19 11:22:27

by Nikita Shubin

Subject: [PATCH v4 1/1] RISC-V: Create unique identification for SoC PMU

From: Nikita Shubin <[email protected]>

Provide RISC-V SBI PMU id to distinguish different cores or SoCs via
"devices/platform/riscv-pmu/id" sysfs entry.

The identification is generated as string of marchid, mimpid, mvendorid
in hex format separated by coma - "0x70032,0x70032,0x0".

The CSRs are detailed in the RISC-V privileged spec [1].
[1] https://github.com/riscv/riscv-isa-manual

Inspired-by: João Mário Domingos <[email protected]>
Signed-off-by: Nikita Shubin <[email protected]>
---
v3->v4:
- use string for pmuid
- rename pmu_sbi_id_show to id_show
- fix error print message in id_show
- fix DEVICE_ATTR to use octal permissions
---
arch/riscv/kernel/sbi.c | 3 +++
drivers/perf/riscv_pmu_sbi.c | 41 ++++++++++++++++++++++++++++++++++
include/linux/perf/riscv_pmu.h | 1 +
3 files changed, 45 insertions(+)

diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
index 775d3322b422..50dd9b6ecc9e 100644
--- a/arch/riscv/kernel/sbi.c
+++ b/arch/riscv/kernel/sbi.c
@@ -627,16 +627,19 @@ long sbi_get_mvendorid(void)
{
return __sbi_base_ecall(SBI_EXT_BASE_GET_MVENDORID);
}
+EXPORT_SYMBOL(sbi_get_mvendorid);

long sbi_get_marchid(void)
{
return __sbi_base_ecall(SBI_EXT_BASE_GET_MARCHID);
}
+EXPORT_SYMBOL(sbi_get_marchid);

long sbi_get_mimpid(void)
{
return __sbi_base_ecall(SBI_EXT_BASE_GET_MIMPID);
}
+EXPORT_SYMBOL(sbi_get_mimpid);

static void sbi_send_cpumask_ipi(const struct cpumask *target)
{
diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
index dca3537a8dcc..be812f855617 100644
--- a/drivers/perf/riscv_pmu_sbi.c
+++ b/drivers/perf/riscv_pmu_sbi.c
@@ -693,6 +693,28 @@ static int pmu_sbi_setup_irqs(struct riscv_pmu *pmu, struct platform_device *pde
return 0;
}

+static ssize_t id_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int len;
+ struct riscv_pmu *pmu = container_of(dev_get_drvdata(dev), struct riscv_pmu, pmu);
+
+ len = sprintf(buf, "%s\n", pmu->pmuid);
+ if (len <= 0)
+ dev_err(dev, "invalid sprintf len: %d\n", len);
+
+ return len;
+}
+
+static DEVICE_ATTR(id, 0644, id_show, NULL);
+
+static struct attribute *pmu_sbi_attrs[] = {
+ &dev_attr_id.attr,
+ NULL
+};
+
+ATTRIBUTE_GROUPS(pmu_sbi);
+
static int pmu_sbi_device_probe(struct platform_device *pdev)
{
struct riscv_pmu *pmu = NULL;
@@ -714,6 +736,14 @@ static int pmu_sbi_device_probe(struct platform_device *pdev)
if (pmu_sbi_get_ctrinfo(num_counters))
goto out_free;

+ /* fill pmuid */
+ pmu->pmuid = kasprintf(GFP_KERNEL, "0x%lx,0x%lx,0x%lx",
+ sbi_get_marchid(),
+ sbi_get_mimpid(),
+ sbi_get_mvendorid());
+ if (!pmu->pmuid)
+ goto out_free_pmuid;
+
ret = pmu_sbi_setup_irqs(pmu, pdev);
if (ret < 0) {
pr_info("Perf sampling/filtering is not supported as sscof extension is not available\n");
@@ -739,8 +769,19 @@ static int pmu_sbi_device_probe(struct platform_device *pdev)
return ret;
}

+ ret = sysfs_create_group(&pdev->dev.kobj, &pmu_sbi_group);
+ if (ret) {
+ dev_err(&pdev->dev, "sysfs creation failed\n");
+ return ret;
+ }
+
+ pdev->dev.groups = pmu_sbi_groups;
+ dev_set_drvdata(&pdev->dev, pmu);
+
return 0;

+out_free_pmuid:
+ kfree(pmu->pmuid);
out_free:
kfree(pmu);
return ret;
diff --git a/include/linux/perf/riscv_pmu.h b/include/linux/perf/riscv_pmu.h
index 46f9b6fe306e..cf3557b77fb8 100644
--- a/include/linux/perf/riscv_pmu.h
+++ b/include/linux/perf/riscv_pmu.h
@@ -42,6 +42,7 @@ struct cpu_hw_events {
struct riscv_pmu {
struct pmu pmu;
char *name;
+ char *pmuid;

irqreturn_t (*handle_irq)(int irq_num, void *dev);

--
2.35.1

2022-06-20 08:04:23

by Geert Uytterhoeven

Subject: Re: [PATCH v4 1/1] RISC-V: Create unique identification for SoC PMU

Hi Nikita,

On Sun, Jun 19, 2022 at 1:11 PM Nikita Shubin <[email protected]> wrote:
> From: Nikita Shubin <[email protected]>
>
> Provide RISC-V SBI PMU id to distinguish different cores or SoCs via
> "devices/platform/riscv-pmu/id" sysfs entry.
>
> The identification is generated as string of marchid, mimpid, mvendorid
> in hex format separated by coma - "0x70032,0x70032,0x0".
>
> The CSRs are detailed in the RISC-V privileged spec [1].
> [1] https://github.com/riscv/riscv-isa-manual
>
> Inspired-by: João Mário Domingos <[email protected]>
> Signed-off-by: Nikita Shubin <[email protected]>

Thanks for your patch!

> --- a/arch/riscv/kernel/sbi.c
> +++ b/arch/riscv/kernel/sbi.c

> --- a/drivers/perf/riscv_pmu_sbi.c
> +++ b/drivers/perf/riscv_pmu_sbi.c
> @@ -693,6 +693,28 @@ static int pmu_sbi_setup_irqs(struct riscv_pmu *pmu, struct platform_device *pde
> return 0;
> }
>
> +static ssize_t id_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + int len;
> + struct riscv_pmu *pmu = container_of(dev_get_drvdata(dev), struct riscv_pmu, pmu);
> +
> + len = sprintf(buf, "%s\n", pmu->pmuid);
> + if (len <= 0)
> + dev_err(dev, "invalid sprintf len: %d\n", len);

How can this fail?

Please use sysfs_emit() instead of sprintf(), and drop the error
message.

> +
> + return len;
> +}

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds

2022-06-20 12:04:30

by Anup Patel

Subject: Re: [PATCH v4 1/1] RISC-V: Create unique identification for SoC PMU

On Sun, Jun 19, 2022 at 4:41 PM Nikita Shubin <[email protected]> wrote:
>
> From: Nikita Shubin <[email protected]>
>
> Provide RISC-V SBI PMU id to distinguish different cores or SoCs via
> "devices/platform/riscv-pmu/id" sysfs entry.
>
> The identification is generated as string of marchid, mimpid, mvendorid
> in hex format separated by coma - "0x70032,0x70032,0x0".
>
> The CSRs are detailed in the RISC-V privileged spec [1].
> [1] https://github.com/riscv/riscv-isa-manual
>
> Inspired-by: João Mário Domingos <[email protected]>
> Signed-off-by: Nikita Shubin <[email protected]>

The mvendorid, marchid, and mimpid can be useful to apps other than
perf tool.

I have tried to extend /proc/cpuinfo with this information which can be
parsed by perf tool:
https://lore.kernel.org/all/[email protected]/

Regards,
Anup

> ---
> v3->v4:
> - use string for pmuid
> - rename pmu_sbi_id_show to id_show
> - fix error print message in id_show
> - fix DEVICE_ATTR to use octal permissions
> ---
> arch/riscv/kernel/sbi.c | 3 +++
> drivers/perf/riscv_pmu_sbi.c | 41 ++++++++++++++++++++++++++++++++++
> include/linux/perf/riscv_pmu.h | 1 +
> 3 files changed, 45 insertions(+)
>
> diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
> index 775d3322b422..50dd9b6ecc9e 100644
> --- a/arch/riscv/kernel/sbi.c
> +++ b/arch/riscv/kernel/sbi.c
> @@ -627,16 +627,19 @@ long sbi_get_mvendorid(void)
> {
> return __sbi_base_ecall(SBI_EXT_BASE_GET_MVENDORID);
> }
> +EXPORT_SYMBOL(sbi_get_mvendorid);
>
> long sbi_get_marchid(void)
> {
> return __sbi_base_ecall(SBI_EXT_BASE_GET_MARCHID);
> }
> +EXPORT_SYMBOL(sbi_get_marchid);
>
> long sbi_get_mimpid(void)
> {
> return __sbi_base_ecall(SBI_EXT_BASE_GET_MIMPID);
> }
> +EXPORT_SYMBOL(sbi_get_mimpid);
>
> static void sbi_send_cpumask_ipi(const struct cpumask *target)
> {
> diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
> index dca3537a8dcc..be812f855617 100644
> --- a/drivers/perf/riscv_pmu_sbi.c
> +++ b/drivers/perf/riscv_pmu_sbi.c
> @@ -693,6 +693,28 @@ static int pmu_sbi_setup_irqs(struct riscv_pmu *pmu, struct platform_device *pde
> return 0;
> }
>
> +static ssize_t id_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + int len;
> + struct riscv_pmu *pmu = container_of(dev_get_drvdata(dev), struct riscv_pmu, pmu);
> +
> + len = sprintf(buf, "%s\n", pmu->pmuid);
> + if (len <= 0)
> + dev_err(dev, "invalid sprintf len: %d\n", len);
> +
> + return len;
> +}
> +
> +static DEVICE_ATTR(id, 0644, id_show, NULL);
> +
> +static struct attribute *pmu_sbi_attrs[] = {
> + &dev_attr_id.attr,
> + NULL
> +};
> +
> +ATTRIBUTE_GROUPS(pmu_sbi);
> +
> static int pmu_sbi_device_probe(struct platform_device *pdev)
> {
> struct riscv_pmu *pmu = NULL;
> @@ -714,6 +736,14 @@ static int pmu_sbi_device_probe(struct platform_device *pdev)
> if (pmu_sbi_get_ctrinfo(num_counters))
> goto out_free;
>
> + /* fill pmuid */
> + pmu->pmuid = kasprintf(GFP_KERNEL, "0x%lx,0x%lx,0x%lx",
> + sbi_get_marchid(),
> + sbi_get_mimpid(),
> + sbi_get_mvendorid());
> + if (!pmu->pmuid)
> + goto out_free_pmuid;
> +
> ret = pmu_sbi_setup_irqs(pmu, pdev);
> if (ret < 0) {
> pr_info("Perf sampling/filtering is not supported as sscof extension is not available\n");
> @@ -739,8 +769,19 @@ static int pmu_sbi_device_probe(struct platform_device *pdev)
> return ret;
> }
>
> + ret = sysfs_create_group(&pdev->dev.kobj, &pmu_sbi_group);
> + if (ret) {
> + dev_err(&pdev->dev, "sysfs creation failed\n");
> + return ret;
> + }
> +
> + pdev->dev.groups = pmu_sbi_groups;
> + dev_set_drvdata(&pdev->dev, pmu);
> +
> return 0;
>
> +out_free_pmuid:
> + kfree(pmu->pmuid);
> out_free:
> kfree(pmu);
> return ret;
> diff --git a/include/linux/perf/riscv_pmu.h b/include/linux/perf/riscv_pmu.h
> index 46f9b6fe306e..cf3557b77fb8 100644
> --- a/include/linux/perf/riscv_pmu.h
> +++ b/include/linux/perf/riscv_pmu.h
> @@ -42,6 +42,7 @@ struct cpu_hw_events {
> struct riscv_pmu {
> struct pmu pmu;
> char *name;
> + char *pmuid;
>
> irqreturn_t (*handle_irq)(int irq_num, void *dev);
>
> --
> 2.35.1
>

2022-06-20 15:07:25

by Nikita Shubin

Subject: Re: [PATCH v4 1/1] RISC-V: Create unique identification for SoC PMU

On Mon, 20 Jun 2022 17:30:58 +0530
Anup Patel <[email protected]> wrote:

> On Sun, Jun 19, 2022 at 4:41 PM Nikita Shubin
> <[email protected]> wrote:
> >
> > From: Nikita Shubin <[email protected]>
> >
> > Provide RISC-V SBI PMU id to distinguish different cores or SoCs via
> > "devices/platform/riscv-pmu/id" sysfs entry.
> >
> > The identification is generated as string of marchid, mimpid,
> > mvendorid in hex format separated by coma - "0x70032,0x70032,0x0".
> >
> > The CSRs are detailed in the RISC-V privileged spec [1].
> > [1] https://github.com/riscv/riscv-isa-manual
> >
> > Inspired-by: João Mário Domingos <[email protected]>
> > Signed-off-by: Nikita Shubin <[email protected]>
>
> The mvendorid, marchid, and mimpid can be useful to apps other than
> perf tool.
>
> I have tried to extend /proc/cpuinfo with this information which can
> be parsed by perf tool:
> https://lore.kernel.org/all/[email protected]/

Atish, what do you think about this ?

RISC-V perf can rely on "/proc/cpuinfo", in some similar manner like
"tools/perf/arch/s390/util/header.c" does.

Can it create problems with pmu identification in case of hetergenous
harts ?

>
> Regards,
> Anup
>
> > ---
> > v3->v4:
> > - use string for pmuid
> > - rename pmu_sbi_id_show to id_show
> > - fix error print message in id_show
> > - fix DEVICE_ATTR to use octal permissions
> > ---
> > arch/riscv/kernel/sbi.c | 3 +++
> > drivers/perf/riscv_pmu_sbi.c | 41
> > ++++++++++++++++++++++++++++++++++ include/linux/perf/riscv_pmu.h |
> > 1 + 3 files changed, 45 insertions(+)
> >
> > diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
> > index 775d3322b422..50dd9b6ecc9e 100644
> > --- a/arch/riscv/kernel/sbi.c
> > +++ b/arch/riscv/kernel/sbi.c
> > @@ -627,16 +627,19 @@ long sbi_get_mvendorid(void)
> > {
> > return __sbi_base_ecall(SBI_EXT_BASE_GET_MVENDORID);
> > }
> > +EXPORT_SYMBOL(sbi_get_mvendorid);
> >
> > long sbi_get_marchid(void)
> > {
> > return __sbi_base_ecall(SBI_EXT_BASE_GET_MARCHID);
> > }
> > +EXPORT_SYMBOL(sbi_get_marchid);
> >
> > long sbi_get_mimpid(void)
> > {
> > return __sbi_base_ecall(SBI_EXT_BASE_GET_MIMPID);
> > }
> > +EXPORT_SYMBOL(sbi_get_mimpid);
> >
> > static void sbi_send_cpumask_ipi(const struct cpumask *target)
> > {
> > diff --git a/drivers/perf/riscv_pmu_sbi.c
> > b/drivers/perf/riscv_pmu_sbi.c index dca3537a8dcc..be812f855617
> > 100644 --- a/drivers/perf/riscv_pmu_sbi.c
> > +++ b/drivers/perf/riscv_pmu_sbi.c
> > @@ -693,6 +693,28 @@ static int pmu_sbi_setup_irqs(struct riscv_pmu
> > *pmu, struct platform_device *pde return 0;
> > }
> >
> > +static ssize_t id_show(struct device *dev,
> > + struct device_attribute *attr, char
> > *buf) +{
> > + int len;
> > + struct riscv_pmu *pmu = container_of(dev_get_drvdata(dev),
> > struct riscv_pmu, pmu); +
> > + len = sprintf(buf, "%s\n", pmu->pmuid);
> > + if (len <= 0)
> > + dev_err(dev, "invalid sprintf len: %d\n", len);
> > +
> > + return len;
> > +}
> > +
> > +static DEVICE_ATTR(id, 0644, id_show, NULL);
> > +
> > +static struct attribute *pmu_sbi_attrs[] = {
> > + &dev_attr_id.attr,
> > + NULL
> > +};
> > +
> > +ATTRIBUTE_GROUPS(pmu_sbi);
> > +
> > static int pmu_sbi_device_probe(struct platform_device *pdev)
> > {
> > struct riscv_pmu *pmu = NULL;
> > @@ -714,6 +736,14 @@ static int pmu_sbi_device_probe(struct
> > platform_device *pdev) if (pmu_sbi_get_ctrinfo(num_counters))
> > goto out_free;
> >
> > + /* fill pmuid */
> > + pmu->pmuid = kasprintf(GFP_KERNEL, "0x%lx,0x%lx,0x%lx",
> > + sbi_get_marchid(),
> > + sbi_get_mimpid(),
> > + sbi_get_mvendorid());
> > + if (!pmu->pmuid)
> > + goto out_free_pmuid;
> > +
> > ret = pmu_sbi_setup_irqs(pmu, pdev);
> > if (ret < 0) {
> > pr_info("Perf sampling/filtering is not supported
> > as sscof extension is not available\n"); @@ -739,8 +769,19 @@
> > static int pmu_sbi_device_probe(struct platform_device *pdev)
> > return ret; }
> >
> > + ret = sysfs_create_group(&pdev->dev.kobj, &pmu_sbi_group);
> > + if (ret) {
> > + dev_err(&pdev->dev, "sysfs creation failed\n");
> > + return ret;
> > + }
> > +
> > + pdev->dev.groups = pmu_sbi_groups;
> > + dev_set_drvdata(&pdev->dev, pmu);
> > +
> > return 0;
> >
> > +out_free_pmuid:
> > + kfree(pmu->pmuid);
> > out_free:
> > kfree(pmu);
> > return ret;
> > diff --git a/include/linux/perf/riscv_pmu.h
> > b/include/linux/perf/riscv_pmu.h index 46f9b6fe306e..cf3557b77fb8
> > 100644 --- a/include/linux/perf/riscv_pmu.h
> > +++ b/include/linux/perf/riscv_pmu.h
> > @@ -42,6 +42,7 @@ struct cpu_hw_events {
> > struct riscv_pmu {
> > struct pmu pmu;
> > char *name;
> > + char *pmuid;
> >
> > irqreturn_t (*handle_irq)(int irq_num, void *dev);
> >
> > --
> > 2.35.1
> >

2022-06-20 15:28:24

by Nikita Shubin

Subject: Re: [PATCH v4 1/1] RISC-V: Create unique identification for SoC PMU

Hello Geert!

On Mon, 20 Jun 2022 09:50:14 +0200
Geert Uytterhoeven <[email protected]> wrote:

> Hi Nikita,
>
> On Sun, Jun 19, 2022 at 1:11 PM Nikita Shubin
> <[email protected]> wrote:
> > From: Nikita Shubin <[email protected]>
> >
> > Provide RISC-V SBI PMU id to distinguish different cores or SoCs via
> > "devices/platform/riscv-pmu/id" sysfs entry.
> >
> > The identification is generated as string of marchid, mimpid,
> > mvendorid in hex format separated by coma - "0x70032,0x70032,0x0".
> >
> > The CSRs are detailed in the RISC-V privileged spec [1].
> > [1] https://github.com/riscv/riscv-isa-manual
> >
> > Inspired-by: João Mário Domingos <[email protected]>
> > Signed-off-by: Nikita Shubin <[email protected]>
>
> Thanks for your patch!
>
> > --- a/arch/riscv/kernel/sbi.c
> > +++ b/arch/riscv/kernel/sbi.c
>
> > --- a/drivers/perf/riscv_pmu_sbi.c
> > +++ b/drivers/perf/riscv_pmu_sbi.c
> > @@ -693,6 +693,28 @@ static int pmu_sbi_setup_irqs(struct riscv_pmu
> > *pmu, struct platform_device *pde return 0;
> > }
> >
> > +static ssize_t id_show(struct device *dev,
> > + struct device_attribute *attr, char
> > *buf) +{
> > + int len;
> > + struct riscv_pmu *pmu = container_of(dev_get_drvdata(dev),
> > struct riscv_pmu, pmu); +
> > + len = sprintf(buf, "%s\n", pmu->pmuid);
> > + if (len <= 0)
> > + dev_err(dev, "invalid sprintf len: %d\n", len);
>
> How can this fail?
>
> Please use sysfs_emit() instead of sprintf(), and drop the error
> message.

Indeed, thank you for your comments.

Also i missed some explicit free:

> > +out_free_pmuid:
> > + kfree(pmu->pmuid);

This is not needed.

>
> > +
> > + return len;
> > +}
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 --
> [email protected]
>
> In personal conversations with technical people, I call myself a
> hacker. But when I'm talking to journalists I just say "programmer"
> or something like that. -- Linus Torvalds

2022-06-20 19:44:18

by Atish Patra

Subject: Re: [PATCH v4 1/1] RISC-V: Create unique identification for SoC PMU

On Mon, Jun 20, 2022 at 7:40 AM Nikita Shubin <[email protected]> wrote:
>
> On Mon, 20 Jun 2022 17:30:58 +0530
> Anup Patel <[email protected]> wrote:
>
> > On Sun, Jun 19, 2022 at 4:41 PM Nikita Shubin
> > <[email protected]> wrote:
> > >
> > > From: Nikita Shubin <[email protected]>
> > >
> > > Provide RISC-V SBI PMU id to distinguish different cores or SoCs via
> > > "devices/platform/riscv-pmu/id" sysfs entry.
> > >
> > > The identification is generated as string of marchid, mimpid,
> > > mvendorid in hex format separated by coma - "0x70032,0x70032,0x0".
> > >
> > > The CSRs are detailed in the RISC-V privileged spec [1].
> > > [1] https://github.com/riscv/riscv-isa-manual
> > >
> > > Inspired-by: João Mário Domingos <[email protected]>
> > > Signed-off-by: Nikita Shubin <[email protected]>
> >
> > The mvendorid, marchid, and mimpid can be useful to apps other than
> > perf tool.
> >
> > I have tried to extend /proc/cpuinfo with this information which can
> > be parsed by perf tool:
> > https://lore.kernel.org/all/[email protected]/
>
> Atish, what do you think about this ?
>
> RISC-V perf can rely on "/proc/cpuinfo", in some similar manner like
> "tools/perf/arch/s390/util/header.c" does.
>

Yes. We can expose these three values either in sysfs or procfs (/proc/cpuinfo).
For perf tool, it shouldn't matter as the header.c will need to
generate the unique cpuid
string from either.

I am not sure if any other userspace tool prefers to parse sysfs
instead of cpuinfo.

> Can it create problems with pmu identification in case of hetergenous
> harts ?
>

Does perf support hetergenous harts at all ? ARM64 code
(tool/perf/arch/arm64/util/header.c)
just breaks out of the loop after finding the first MIDR.

> >
> > Regards,
> > Anup
> >
> > > ---
> > > v3->v4:
> > > - use string for pmuid
> > > - rename pmu_sbi_id_show to id_show
> > > - fix error print message in id_show
> > > - fix DEVICE_ATTR to use octal permissions
> > > ---
> > > arch/riscv/kernel/sbi.c | 3 +++
> > > drivers/perf/riscv_pmu_sbi.c | 41
> > > ++++++++++++++++++++++++++++++++++ include/linux/perf/riscv_pmu.h |
> > > 1 + 3 files changed, 45 insertions(+)
> > >
> > > diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
> > > index 775d3322b422..50dd9b6ecc9e 100644
> > > --- a/arch/riscv/kernel/sbi.c
> > > +++ b/arch/riscv/kernel/sbi.c
> > > @@ -627,16 +627,19 @@ long sbi_get_mvendorid(void)
> > > {
> > > return __sbi_base_ecall(SBI_EXT_BASE_GET_MVENDORID);
> > > }
> > > +EXPORT_SYMBOL(sbi_get_mvendorid);
> > >
> > > long sbi_get_marchid(void)
> > > {
> > > return __sbi_base_ecall(SBI_EXT_BASE_GET_MARCHID);
> > > }
> > > +EXPORT_SYMBOL(sbi_get_marchid);
> > >
> > > long sbi_get_mimpid(void)
> > > {
> > > return __sbi_base_ecall(SBI_EXT_BASE_GET_MIMPID);
> > > }
> > > +EXPORT_SYMBOL(sbi_get_mimpid);
> > >
> > > static void sbi_send_cpumask_ipi(const struct cpumask *target)
> > > {
> > > diff --git a/drivers/perf/riscv_pmu_sbi.c
> > > b/drivers/perf/riscv_pmu_sbi.c index dca3537a8dcc..be812f855617
> > > 100644 --- a/drivers/perf/riscv_pmu_sbi.c
> > > +++ b/drivers/perf/riscv_pmu_sbi.c
> > > @@ -693,6 +693,28 @@ static int pmu_sbi_setup_irqs(struct riscv_pmu
> > > *pmu, struct platform_device *pde return 0;
> > > }
> > >
> > > +static ssize_t id_show(struct device *dev,
> > > + struct device_attribute *attr, char
> > > *buf) +{
> > > + int len;
> > > + struct riscv_pmu *pmu = container_of(dev_get_drvdata(dev),
> > > struct riscv_pmu, pmu); +
> > > + len = sprintf(buf, "%s\n", pmu->pmuid);
> > > + if (len <= 0)
> > > + dev_err(dev, "invalid sprintf len: %d\n", len);
> > > +
> > > + return len;
> > > +}
> > > +
> > > +static DEVICE_ATTR(id, 0644, id_show, NULL);
> > > +
> > > +static struct attribute *pmu_sbi_attrs[] = {
> > > + &dev_attr_id.attr,
> > > + NULL
> > > +};
> > > +
> > > +ATTRIBUTE_GROUPS(pmu_sbi);
> > > +
> > > static int pmu_sbi_device_probe(struct platform_device *pdev)
> > > {
> > > struct riscv_pmu *pmu = NULL;
> > > @@ -714,6 +736,14 @@ static int pmu_sbi_device_probe(struct
> > > platform_device *pdev) if (pmu_sbi_get_ctrinfo(num_counters))
> > > goto out_free;
> > >
> > > + /* fill pmuid */
> > > + pmu->pmuid = kasprintf(GFP_KERNEL, "0x%lx,0x%lx,0x%lx",
> > > + sbi_get_marchid(),
> > > + sbi_get_mimpid(),
> > > + sbi_get_mvendorid());
> > > + if (!pmu->pmuid)
> > > + goto out_free_pmuid;
> > > +
> > > ret = pmu_sbi_setup_irqs(pmu, pdev);
> > > if (ret < 0) {
> > > pr_info("Perf sampling/filtering is not supported
> > > as sscof extension is not available\n"); @@ -739,8 +769,19 @@
> > > static int pmu_sbi_device_probe(struct platform_device *pdev)
> > > return ret; }
> > >
> > > + ret = sysfs_create_group(&pdev->dev.kobj, &pmu_sbi_group);
> > > + if (ret) {
> > > + dev_err(&pdev->dev, "sysfs creation failed\n");
> > > + return ret;
> > > + }
> > > +
> > > + pdev->dev.groups = pmu_sbi_groups;
> > > + dev_set_drvdata(&pdev->dev, pmu);
> > > +
> > > return 0;
> > >
> > > +out_free_pmuid:
> > > + kfree(pmu->pmuid);
> > > out_free:
> > > kfree(pmu);
> > > return ret;
> > > diff --git a/include/linux/perf/riscv_pmu.h
> > > b/include/linux/perf/riscv_pmu.h index 46f9b6fe306e..cf3557b77fb8
> > > 100644 --- a/include/linux/perf/riscv_pmu.h
> > > +++ b/include/linux/perf/riscv_pmu.h
> > > @@ -42,6 +42,7 @@ struct cpu_hw_events {
> > > struct riscv_pmu {
> > > struct pmu pmu;
> > > char *name;
> > > + char *pmuid;
> > >
> > > irqreturn_t (*handle_irq)(int irq_num, void *dev);
> > >
> > > --
> > > 2.35.1
> > >
>


--
Regards,
Atish

2022-06-21 08:21:25

by Anup Patel

Subject: Re: [PATCH v4 1/1] RISC-V: Create unique identification for SoC PMU

On Tue, Jun 21, 2022 at 1:13 PM Nikita Shubin <[email protected]> wrote:
>
> Hello Anup!
>
> On Mon, 20 Jun 2022 12:40:20 -0700
> Atish Patra <[email protected]> wrote:
>
> > On Mon, Jun 20, 2022 at 7:40 AM Nikita Shubin
> > <[email protected]> wrote:
> > >
> > > On Mon, 20 Jun 2022 17:30:58 +0530
> > > Anup Patel <[email protected]> wrote:
> > >
> > > > On Sun, Jun 19, 2022 at 4:41 PM Nikita Shubin
> > > > <[email protected]> wrote:
> > > > >
> > > > > From: Nikita Shubin <[email protected]>
> > > > >
> > > > > Provide RISC-V SBI PMU id to distinguish different cores or
> > > > > SoCs via "devices/platform/riscv-pmu/id" sysfs entry.
> > > > >
> > > > > The identification is generated as string of marchid, mimpid,
> > > > > mvendorid in hex format separated by coma -
> > > > > "0x70032,0x70032,0x0".
> > > > >
> > > > > The CSRs are detailed in the RISC-V privileged spec [1].
> > > > > [1] https://github.com/riscv/riscv-isa-manual
> > > > >
> > > > > Inspired-by: João Mário Domingos <[email protected]>
> > > > > Signed-off-by: Nikita Shubin <[email protected]>
> > > >
> > > > The mvendorid, marchid, and mimpid can be useful to apps other
> > > > than perf tool.
> > > >
> > > > I have tried to extend /proc/cpuinfo with this information which
> > > > can be parsed by perf tool:
> > > > https://lore.kernel.org/all/[email protected]/
> > > >
> > >
> > > Atish, what do you think about this ?
> > >
> > > RISC-V perf can rely on "/proc/cpuinfo", in some similar manner like
> > > "tools/perf/arch/s390/util/header.c" does.
> > >
> >
> > Yes. We can expose these three values either in sysfs or procfs
> > (/proc/cpuinfo). For perf tool, it shouldn't matter as the header.c
> > will need to generate the unique cpuid
> > string from either.
> >
> > I am not sure if any other userspace tool prefers to parse sysfs
> > instead of cpuinfo.
>
> Okay - let's stick to /proc/cpuinfo.

Sounds good.

You might have to write /proc/cpuinfo parsing code in perf tool
header.c. Do you plan to send v4 of perf tool patches ??

Regards,
Anup

>
> >
> > > Can it create problems with pmu identification in case of
> > > hetergenous harts ?
> > >
> >
> > Does perf support hetergenous harts at all ? ARM64 code
> > (tool/perf/arch/arm64/util/header.c)
> > just breaks out of the loop after finding the first MIDR.
> >
> > > >
> > > > Regards,
> > > > Anup
> > > >
> > > > > ---
> > > > > v3->v4:
> > > > > - use string for pmuid
> > > > > - rename pmu_sbi_id_show to id_show
> > > > > - fix error print message in id_show
> > > > > - fix DEVICE_ATTR to use octal permissions
> > > > > ---
> > > > > arch/riscv/kernel/sbi.c | 3 +++
> > > > > drivers/perf/riscv_pmu_sbi.c | 41
> > > > > ++++++++++++++++++++++++++++++++++
> > > > > include/linux/perf/riscv_pmu.h | 1 + 3 files changed, 45
> > > > > insertions(+)
> > > > >
> > > > > diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
> > > > > index 775d3322b422..50dd9b6ecc9e 100644
> > > > > --- a/arch/riscv/kernel/sbi.c
> > > > > +++ b/arch/riscv/kernel/sbi.c
> > > > > @@ -627,16 +627,19 @@ long sbi_get_mvendorid(void)
> > > > > {
> > > > > return __sbi_base_ecall(SBI_EXT_BASE_GET_MVENDORID);
> > > > > }
> > > > > +EXPORT_SYMBOL(sbi_get_mvendorid);
> > > > >
> > > > > long sbi_get_marchid(void)
> > > > > {
> > > > > return __sbi_base_ecall(SBI_EXT_BASE_GET_MARCHID);
> > > > > }
> > > > > +EXPORT_SYMBOL(sbi_get_marchid);
> > > > >
> > > > > long sbi_get_mimpid(void)
> > > > > {
> > > > > return __sbi_base_ecall(SBI_EXT_BASE_GET_MIMPID);
> > > > > }
> > > > > +EXPORT_SYMBOL(sbi_get_mimpid);
> > > > >
> > > > > static void sbi_send_cpumask_ipi(const struct cpumask *target)
> > > > > {
> > > > > diff --git a/drivers/perf/riscv_pmu_sbi.c
> > > > > b/drivers/perf/riscv_pmu_sbi.c index dca3537a8dcc..be812f855617
> > > > > 100644 --- a/drivers/perf/riscv_pmu_sbi.c
> > > > > +++ b/drivers/perf/riscv_pmu_sbi.c
> > > > > @@ -693,6 +693,28 @@ static int pmu_sbi_setup_irqs(struct
> > > > > riscv_pmu *pmu, struct platform_device *pde return 0;
> > > > > }
> > > > >
> > > > > +static ssize_t id_show(struct device *dev,
> > > > > + struct device_attribute *attr,
> > > > > char *buf) +{
> > > > > + int len;
> > > > > + struct riscv_pmu *pmu =
> > > > > container_of(dev_get_drvdata(dev), struct riscv_pmu, pmu); +
> > > > > + len = sprintf(buf, "%s\n", pmu->pmuid);
> > > > > + if (len <= 0)
> > > > > + dev_err(dev, "invalid sprintf len: %d\n", len);
> > > > > +
> > > > > + return len;
> > > > > +}
> > > > > +
> > > > > +static DEVICE_ATTR(id, 0644, id_show, NULL);
> > > > > +
> > > > > +static struct attribute *pmu_sbi_attrs[] = {
> > > > > + &dev_attr_id.attr,
> > > > > + NULL
> > > > > +};
> > > > > +
> > > > > +ATTRIBUTE_GROUPS(pmu_sbi);
> > > > > +
> > > > > static int pmu_sbi_device_probe(struct platform_device *pdev)
> > > > > {
> > > > > struct riscv_pmu *pmu = NULL;
> > > > > @@ -714,6 +736,14 @@ static int pmu_sbi_device_probe(struct
> > > > > platform_device *pdev) if (pmu_sbi_get_ctrinfo(num_counters))
> > > > > goto out_free;
> > > > >
> > > > > + /* fill pmuid */
> > > > > + pmu->pmuid = kasprintf(GFP_KERNEL, "0x%lx,0x%lx,0x%lx",
> > > > > + sbi_get_marchid(),
> > > > > + sbi_get_mimpid(),
> > > > > + sbi_get_mvendorid());
> > > > > + if (!pmu->pmuid)
> > > > > + goto out_free_pmuid;
> > > > > +
> > > > > ret = pmu_sbi_setup_irqs(pmu, pdev);
> > > > > if (ret < 0) {
> > > > > pr_info("Perf sampling/filtering is not
> > > > > supported as sscof extension is not available\n"); @@ -739,8
> > > > > +769,19 @@ static int pmu_sbi_device_probe(struct
> > > > > platform_device *pdev) return ret; }
> > > > >
> > > > > + ret = sysfs_create_group(&pdev->dev.kobj,
> > > > > &pmu_sbi_group);
> > > > > + if (ret) {
> > > > > + dev_err(&pdev->dev, "sysfs creation failed\n");
> > > > > + return ret;
> > > > > + }
> > > > > +
> > > > > + pdev->dev.groups = pmu_sbi_groups;
> > > > > + dev_set_drvdata(&pdev->dev, pmu);
> > > > > +
> > > > > return 0;
> > > > >
> > > > > +out_free_pmuid:
> > > > > + kfree(pmu->pmuid);
> > > > > out_free:
> > > > > kfree(pmu);
> > > > > return ret;
> > > > > diff --git a/include/linux/perf/riscv_pmu.h
> > > > > b/include/linux/perf/riscv_pmu.h index
> > > > > 46f9b6fe306e..cf3557b77fb8 100644 ---
> > > > > a/include/linux/perf/riscv_pmu.h +++
> > > > > b/include/linux/perf/riscv_pmu.h @@ -42,6 +42,7 @@ struct
> > > > > cpu_hw_events { struct riscv_pmu {
> > > > > struct pmu pmu;
> > > > > char *name;
> > > > > + char *pmuid;
> > > > >
> > > > > irqreturn_t (*handle_irq)(int irq_num, void *dev);
> > > > >
> > > > > --
> > > > > 2.35.1
> > > > >
> > >
> >
> >
>

2022-06-21 08:24:15

by Nikita Shubin

Subject: Re: [PATCH v4 1/1] RISC-V: Create unique identification for SoC PMU

Hello Anup!

On Tue, 21 Jun 2022 13:21:11 +0530
Anup Patel <[email protected]> wrote:

> On Tue, Jun 21, 2022 at 1:13 PM Nikita Shubin
> <[email protected]> wrote:
> >
> > Hello Anup!
> >
> > On Mon, 20 Jun 2022 12:40:20 -0700
> > Atish Patra <[email protected]> wrote:
> >
> > > On Mon, Jun 20, 2022 at 7:40 AM Nikita Shubin
> > > <[email protected]> wrote:
> > > >
> > > > On Mon, 20 Jun 2022 17:30:58 +0530
> > > > Anup Patel <[email protected]> wrote:
> > > >
> > > > > On Sun, Jun 19, 2022 at 4:41 PM Nikita Shubin
> > > > > <[email protected]> wrote:
> > > > > >
> > > > > > From: Nikita Shubin <[email protected]>
> > > > > >
> > > > > > Provide RISC-V SBI PMU id to distinguish different cores or
> > > > > > SoCs via "devices/platform/riscv-pmu/id" sysfs entry.
> > > > > >
> > > > > > The identification is generated as string of marchid,
> > > > > > mimpid, mvendorid in hex format separated by coma -
> > > > > > "0x70032,0x70032,0x0".
> > > > > >
> > > > > > The CSRs are detailed in the RISC-V privileged spec [1].
> > > > > > [1] https://github.com/riscv/riscv-isa-manual
> > > > > >
> > > > > > Inspired-by: João Mário Domingos
> > > > > > <[email protected]> Signed-off-by: Nikita
> > > > > > Shubin <[email protected]>
> > > > >
> > > > > The mvendorid, marchid, and mimpid can be useful to apps other
> > > > > than perf tool.
> > > > >
> > > > > I have tried to extend /proc/cpuinfo with this information
> > > > > which can be parsed by perf tool:
> > > > > https://lore.kernel.org/all/[email protected]/
> > > > >
> > > >
> > > > Atish, what do you think about this ?
> > > >
> > > > RISC-V perf can rely on "/proc/cpuinfo", in some similar manner
> > > > like "tools/perf/arch/s390/util/header.c" does.
> > > >
> > >
> > > Yes. We can expose these three values either in sysfs or procfs
> > > (/proc/cpuinfo). For perf tool, it shouldn't matter as the
> > > header.c will need to generate the unique cpuid
> > > string from either.
> > >
> > > I am not sure if any other userspace tool prefers to parse sysfs
> > > instead of cpuinfo.
> >
> > Okay - let's stick to /proc/cpuinfo.
>
> Sounds good.
>
> You might have to write /proc/cpuinfo parsing code in perf tool
> header.c. Do you plan to send v4 of perf tool patches ??

Yes, but i might split it into separate series, not to mix perf headers
and U74 pmu-events bindings, i ll also add some SBI firmware event
bindings to make things easier.

>
> Regards,
> Anup
>
> >
> > >
> > > > Can it create problems with pmu identification in case of
> > > > hetergenous harts ?
> > > >
> > >
> > > Does perf support hetergenous harts at all ? ARM64 code
> > > (tool/perf/arch/arm64/util/header.c)
> > > just breaks out of the loop after finding the first MIDR.
> > >
> > > > >
> > > > > Regards,
> > > > > Anup
> > > > >
> > > > > > ---
> > > > > > v3->v4:
> > > > > > - use string for pmuid
> > > > > > - rename pmu_sbi_id_show to id_show
> > > > > > - fix error print message in id_show
> > > > > > - fix DEVICE_ATTR to use octal permissions
> > > > > > ---
> > > > > > arch/riscv/kernel/sbi.c | 3 +++
> > > > > > drivers/perf/riscv_pmu_sbi.c | 41
> > > > > > ++++++++++++++++++++++++++++++++++
> > > > > > include/linux/perf/riscv_pmu.h | 1 + 3 files changed, 45
> > > > > > insertions(+)
> > > > > >
> > > > > > diff --git a/arch/riscv/kernel/sbi.c
> > > > > > b/arch/riscv/kernel/sbi.c index 775d3322b422..50dd9b6ecc9e
> > > > > > 100644 --- a/arch/riscv/kernel/sbi.c
> > > > > > +++ b/arch/riscv/kernel/sbi.c
> > > > > > @@ -627,16 +627,19 @@ long sbi_get_mvendorid(void)
> > > > > > {
> > > > > > return __sbi_base_ecall(SBI_EXT_BASE_GET_MVENDORID);
> > > > > > }
> > > > > > +EXPORT_SYMBOL(sbi_get_mvendorid);
> > > > > >
> > > > > > long sbi_get_marchid(void)
> > > > > > {
> > > > > > return __sbi_base_ecall(SBI_EXT_BASE_GET_MARCHID);
> > > > > > }
> > > > > > +EXPORT_SYMBOL(sbi_get_marchid);
> > > > > >
> > > > > > long sbi_get_mimpid(void)
> > > > > > {
> > > > > > return __sbi_base_ecall(SBI_EXT_BASE_GET_MIMPID);
> > > > > > }
> > > > > > +EXPORT_SYMBOL(sbi_get_mimpid);
> > > > > >
> > > > > > static void sbi_send_cpumask_ipi(const struct cpumask
> > > > > > *target) {
> > > > > > diff --git a/drivers/perf/riscv_pmu_sbi.c
> > > > > > b/drivers/perf/riscv_pmu_sbi.c index
> > > > > > dca3537a8dcc..be812f855617 100644 ---
> > > > > > a/drivers/perf/riscv_pmu_sbi.c +++
> > > > > > b/drivers/perf/riscv_pmu_sbi.c @@ -693,6 +693,28 @@ static
> > > > > > int pmu_sbi_setup_irqs(struct riscv_pmu *pmu, struct
> > > > > > platform_device *pde return 0; }
> > > > > >
> > > > > > +static ssize_t id_show(struct device *dev,
> > > > > > + struct device_attribute
> > > > > > *attr, char *buf) +{
> > > > > > + int len;
> > > > > > + struct riscv_pmu *pmu =
> > > > > > container_of(dev_get_drvdata(dev), struct riscv_pmu, pmu); +
> > > > > > + len = sprintf(buf, "%s\n", pmu->pmuid);
> > > > > > + if (len <= 0)
> > > > > > + dev_err(dev, "invalid sprintf len: %d\n",
> > > > > > len); +
> > > > > > + return len;
> > > > > > +}
> > > > > > +
> > > > > > +static DEVICE_ATTR(id, 0644, id_show, NULL);
> > > > > > +
> > > > > > +static struct attribute *pmu_sbi_attrs[] = {
> > > > > > + &dev_attr_id.attr,
> > > > > > + NULL
> > > > > > +};
> > > > > > +
> > > > > > +ATTRIBUTE_GROUPS(pmu_sbi);
> > > > > > +
> > > > > > static int pmu_sbi_device_probe(struct platform_device
> > > > > > *pdev) {
> > > > > > struct riscv_pmu *pmu = NULL;
> > > > > > @@ -714,6 +736,14 @@ static int pmu_sbi_device_probe(struct
> > > > > > platform_device *pdev) if
> > > > > > (pmu_sbi_get_ctrinfo(num_counters)) goto out_free;
> > > > > >
> > > > > > + /* fill pmuid */
> > > > > > + pmu->pmuid = kasprintf(GFP_KERNEL,
> > > > > > "0x%lx,0x%lx,0x%lx",
> > > > > > + sbi_get_marchid(),
> > > > > > + sbi_get_mimpid(),
> > > > > > + sbi_get_mvendorid());
> > > > > > + if (!pmu->pmuid)
> > > > > > + goto out_free_pmuid;
> > > > > > +
> > > > > > ret = pmu_sbi_setup_irqs(pmu, pdev);
> > > > > > if (ret < 0) {
> > > > > > pr_info("Perf sampling/filtering is not
> > > > > > supported as sscof extension is not available\n"); @@ -739,8
> > > > > > +769,19 @@ static int pmu_sbi_device_probe(struct
> > > > > > platform_device *pdev) return ret; }
> > > > > >
> > > > > > + ret = sysfs_create_group(&pdev->dev.kobj,
> > > > > > &pmu_sbi_group);
> > > > > > + if (ret) {
> > > > > > + dev_err(&pdev->dev, "sysfs creation
> > > > > > failed\n");
> > > > > > + return ret;
> > > > > > + }
> > > > > > +
> > > > > > + pdev->dev.groups = pmu_sbi_groups;
> > > > > > + dev_set_drvdata(&pdev->dev, pmu);
> > > > > > +
> > > > > > return 0;
> > > > > >
> > > > > > +out_free_pmuid:
> > > > > > + kfree(pmu->pmuid);
> > > > > > out_free:
> > > > > > kfree(pmu);
> > > > > > return ret;
> > > > > > diff --git a/include/linux/perf/riscv_pmu.h
> > > > > > b/include/linux/perf/riscv_pmu.h index
> > > > > > 46f9b6fe306e..cf3557b77fb8 100644 ---
> > > > > > a/include/linux/perf/riscv_pmu.h +++
> > > > > > b/include/linux/perf/riscv_pmu.h @@ -42,6 +42,7 @@ struct
> > > > > > cpu_hw_events { struct riscv_pmu {
> > > > > > struct pmu pmu;
> > > > > > char *name;
> > > > > > + char *pmuid;
> > > > > >
> > > > > > irqreturn_t (*handle_irq)(int irq_num, void
> > > > > > *dev);
> > > > > >
> > > > > > --
> > > > > > 2.35.1
> > > > > >
> > > >
> > >
> > >
> >

2022-06-21 08:42:09

by Nikita Shubin

Subject: Re: [PATCH v4 1/1] RISC-V: Create unique identification for SoC PMU

Hello Anup!

On Mon, 20 Jun 2022 12:40:20 -0700
Atish Patra <[email protected]> wrote:

> On Mon, Jun 20, 2022 at 7:40 AM Nikita Shubin
> <[email protected]> wrote:
> >
> > On Mon, 20 Jun 2022 17:30:58 +0530
> > Anup Patel <[email protected]> wrote:
> >
> > > On Sun, Jun 19, 2022 at 4:41 PM Nikita Shubin
> > > <[email protected]> wrote:
> > > >
> > > > From: Nikita Shubin <[email protected]>
> > > >
> > > > Provide RISC-V SBI PMU id to distinguish different cores or
> > > > SoCs via "devices/platform/riscv-pmu/id" sysfs entry.
> > > >
> > > > The identification is generated as string of marchid, mimpid,
> > > > mvendorid in hex format separated by coma -
> > > > "0x70032,0x70032,0x0".
> > > >
> > > > The CSRs are detailed in the RISC-V privileged spec [1].
> > > > [1] https://github.com/riscv/riscv-isa-manual
> > > >
> > > > Inspired-by: João Mário Domingos <[email protected]>
> > > > Signed-off-by: Nikita Shubin <[email protected]>
> > >
> > > The mvendorid, marchid, and mimpid can be useful to apps other
> > > than perf tool.
> > >
> > > I have tried to extend /proc/cpuinfo with this information which
> > > can be parsed by perf tool:
> > > https://lore.kernel.org/all/[email protected]/
> > >
> >
> > Atish, what do you think about this ?
> >
> > RISC-V perf can rely on "/proc/cpuinfo", in some similar manner like
> > "tools/perf/arch/s390/util/header.c" does.
> >
>
> Yes. We can expose these three values either in sysfs or procfs
> (/proc/cpuinfo). For perf tool, it shouldn't matter as the header.c
> will need to generate the unique cpuid
> string from either.
>
> I am not sure if any other userspace tool prefers to parse sysfs
> instead of cpuinfo.

Okay - let's stick to /proc/cpuinfo.

>
> > Can it create problems with pmu identification in case of
> > hetergenous harts ?
> >
>
> Does perf support hetergenous harts at all ? ARM64 code
> (tool/perf/arch/arm64/util/header.c)
> just breaks out of the loop after finding the first MIDR.
>
> > >
> > > Regards,
> > > Anup
> > >
> > > > ---
> > > > v3->v4:
> > > > - use string for pmuid
> > > > - rename pmu_sbi_id_show to id_show
> > > > - fix error print message in id_show
> > > > - fix DEVICE_ATTR to use octal permissions
> > > > ---
> > > > arch/riscv/kernel/sbi.c | 3 +++
> > > > drivers/perf/riscv_pmu_sbi.c | 41
> > > > ++++++++++++++++++++++++++++++++++
> > > > include/linux/perf/riscv_pmu.h | 1 + 3 files changed, 45
> > > > insertions(+)
> > > >
> > > > diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
> > > > index 775d3322b422..50dd9b6ecc9e 100644
> > > > --- a/arch/riscv/kernel/sbi.c
> > > > +++ b/arch/riscv/kernel/sbi.c
> > > > @@ -627,16 +627,19 @@ long sbi_get_mvendorid(void)
> > > > {
> > > > return __sbi_base_ecall(SBI_EXT_BASE_GET_MVENDORID);
> > > > }
> > > > +EXPORT_SYMBOL(sbi_get_mvendorid);
> > > >
> > > > long sbi_get_marchid(void)
> > > > {
> > > > return __sbi_base_ecall(SBI_EXT_BASE_GET_MARCHID);
> > > > }
> > > > +EXPORT_SYMBOL(sbi_get_marchid);
> > > >
> > > > long sbi_get_mimpid(void)
> > > > {
> > > > return __sbi_base_ecall(SBI_EXT_BASE_GET_MIMPID);
> > > > }
> > > > +EXPORT_SYMBOL(sbi_get_mimpid);
> > > >
> > > > static void sbi_send_cpumask_ipi(const struct cpumask *target)
> > > > {
> > > > diff --git a/drivers/perf/riscv_pmu_sbi.c
> > > > b/drivers/perf/riscv_pmu_sbi.c index dca3537a8dcc..be812f855617
> > > > 100644 --- a/drivers/perf/riscv_pmu_sbi.c
> > > > +++ b/drivers/perf/riscv_pmu_sbi.c
> > > > @@ -693,6 +693,28 @@ static int pmu_sbi_setup_irqs(struct
> > > > riscv_pmu *pmu, struct platform_device *pde return 0;
> > > > }
> > > >
> > > > +static ssize_t id_show(struct device *dev,
> > > > + struct device_attribute *attr,
> > > > char *buf) +{
> > > > + int len;
> > > > + struct riscv_pmu *pmu =
> > > > container_of(dev_get_drvdata(dev), struct riscv_pmu, pmu); +
> > > > + len = sprintf(buf, "%s\n", pmu->pmuid);
> > > > + if (len <= 0)
> > > > + dev_err(dev, "invalid sprintf len: %d\n", len);
> > > > +
> > > > + return len;
> > > > +}
> > > > +
> > > > +static DEVICE_ATTR(id, 0644, id_show, NULL);
> > > > +
> > > > +static struct attribute *pmu_sbi_attrs[] = {
> > > > + &dev_attr_id.attr,
> > > > + NULL
> > > > +};
> > > > +
> > > > +ATTRIBUTE_GROUPS(pmu_sbi);
> > > > +
> > > > static int pmu_sbi_device_probe(struct platform_device *pdev)
> > > > {
> > > > struct riscv_pmu *pmu = NULL;
> > > > @@ -714,6 +736,14 @@ static int pmu_sbi_device_probe(struct
> > > > platform_device *pdev) if (pmu_sbi_get_ctrinfo(num_counters))
> > > > goto out_free;
> > > >
> > > > + /* fill pmuid */
> > > > + pmu->pmuid = kasprintf(GFP_KERNEL, "0x%lx,0x%lx,0x%lx",
> > > > + sbi_get_marchid(),
> > > > + sbi_get_mimpid(),
> > > > + sbi_get_mvendorid());
> > > > + if (!pmu->pmuid)
> > > > + goto out_free_pmuid;
> > > > +
> > > > ret = pmu_sbi_setup_irqs(pmu, pdev);
> > > > if (ret < 0) {
> > > > pr_info("Perf sampling/filtering is not
> > > > supported as sscof extension is not available\n"); @@ -739,8
> > > > +769,19 @@ static int pmu_sbi_device_probe(struct
> > > > platform_device *pdev) return ret; }
> > > >
> > > > + ret = sysfs_create_group(&pdev->dev.kobj,
> > > > &pmu_sbi_group);
> > > > + if (ret) {
> > > > + dev_err(&pdev->dev, "sysfs creation failed\n");
> > > > + return ret;
> > > > + }
> > > > +
> > > > + pdev->dev.groups = pmu_sbi_groups;
> > > > + dev_set_drvdata(&pdev->dev, pmu);
> > > > +
> > > > return 0;
> > > >
> > > > +out_free_pmuid:
> > > > + kfree(pmu->pmuid);
> > > > out_free:
> > > > kfree(pmu);
> > > > return ret;
> > > > diff --git a/include/linux/perf/riscv_pmu.h
> > > > b/include/linux/perf/riscv_pmu.h index
> > > > 46f9b6fe306e..cf3557b77fb8 100644 ---
> > > > a/include/linux/perf/riscv_pmu.h +++
> > > > b/include/linux/perf/riscv_pmu.h @@ -42,6 +42,7 @@ struct
> > > > cpu_hw_events { struct riscv_pmu {
> > > > struct pmu pmu;
> > > > char *name;
> > > > + char *pmuid;
> > > >
> > > > irqreturn_t (*handle_irq)(int irq_num, void *dev);
> > > >
> > > > --
> > > > 2.35.1
> > > >
> >
>
>