2023-08-01 10:06:35

by Anshuman Khandual

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Subject: [PATCH V2 2/4] arm_pmu: acpi: Add a representative platform device for TRBE

ACPI TRBE does not have a HID for identification which could create and add
a platform device into the platform bus. Also without a platform device, it
cannot be probed and bound to a platform driver.

This creates a dummy platform device for TRBE after ascertaining that ACPI
provides required interrupts uniformly across all cpus on the system. This
device gets created inside drivers/perf/arm_pmu_acpi.c to accommodate TRBE
being built as a module.

Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Anshuman Khandual <[email protected]>
---
arch/arm64/include/asm/acpi.h | 3 +++
drivers/perf/arm_pmu_acpi.c | 37 ++++++++++++++++++++++++++++++++++-
include/linux/perf/arm_pmu.h | 1 +
3 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index bd68e1b7f29f..4d537d56eb84 100644
--- a/arch/arm64/include/asm/acpi.h
+++ b/arch/arm64/include/asm/acpi.h
@@ -42,6 +42,9 @@
#define ACPI_MADT_GICC_SPE (offsetof(struct acpi_madt_generic_interrupt, \
spe_interrupt) + sizeof(u16))

+#define ACPI_MADT_GICC_TRBE (offsetof(struct acpi_madt_generic_interrupt, \
+ trbe_interrupt) + sizeof(u16))
+
/* Basic configuration for ACPI */
#ifdef CONFIG_ACPI
pgprot_t __acpi_get_mem_attribute(phys_addr_t addr);
diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c
index d9d5a7bbb92f..1bcda26282fc 100644
--- a/drivers/perf/arm_pmu_acpi.c
+++ b/drivers/perf/arm_pmu_acpi.c
@@ -69,7 +69,7 @@ static void arm_pmu_acpi_unregister_irq(int cpu)
acpi_unregister_gsi(gsi);
}

-#if IS_ENABLED(CONFIG_ARM_SPE_PMU)
+#if IS_ENABLED(CONFIG_ARM_SPE_PMU) || IS_ENABLED(CONFIG_CORESIGHT_TRBE)
static int
arm_acpi_register_pmu_device(struct platform_device *pdev, u8 len,
u16 (*parse_gsi)(struct acpi_madt_generic_interrupt *))
@@ -169,6 +169,40 @@ static inline void arm_spe_acpi_register_device(void)
}
#endif /* CONFIG_ARM_SPE_PMU */

+#ifdef CONFIG_CORESIGHT_TRBE
+static struct resource trbe_resources[] = {
+ {
+ /* irq */
+ .flags = IORESOURCE_IRQ,
+ }
+};
+
+static struct platform_device trbe_dev = {
+ .name = ARMV8_TRBE_PDEV_NAME,
+ .id = -1,
+ .resource = trbe_resources,
+ .num_resources = ARRAY_SIZE(trbe_resources)
+};
+
+static u16 arm_trbe_parse_gsi(struct acpi_madt_generic_interrupt *gicc)
+{
+ return gicc->trbe_interrupt;
+}
+
+static void arm_trbe_acpi_register_device(void)
+{
+ int ret = arm_acpi_register_pmu_device(&trbe_dev, ACPI_MADT_GICC_TRBE,
+ arm_trbe_parse_gsi);
+ if (ret)
+ pr_warn("ACPI: TRBE: Unable to register device\n");
+}
+#else
+static inline void arm_trbe_acpi_register_device(void)
+{
+
+}
+#endif /* CONFIG_CORESIGHT_TRBE */
+
static int arm_pmu_acpi_parse_irqs(void)
{
int irq, cpu, irq_cpu, err;
@@ -404,6 +438,7 @@ static int arm_pmu_acpi_init(void)
return 0;

arm_spe_acpi_register_device();
+ arm_trbe_acpi_register_device();

return 0;
}
diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
index a0801f68762b..7ec26d21303d 100644
--- a/include/linux/perf/arm_pmu.h
+++ b/include/linux/perf/arm_pmu.h
@@ -187,5 +187,6 @@ void armpmu_free_irq(int irq, int cpu);
#endif /* CONFIG_ARM_PMU */

#define ARMV8_SPE_PDEV_NAME "arm,spe-v1"
+#define ARMV8_TRBE_PDEV_NAME "arm-trbe-acpi"

#endif /* __ARM_PMU_H__ */
--
2.25.1



2023-08-01 15:51:41

by Will Deacon

[permalink] [raw]
Subject: Re: [PATCH V2 2/4] arm_pmu: acpi: Add a representative platform device for TRBE

On Tue, Aug 01, 2023 at 03:10:50PM +0530, Anshuman Khandual wrote:
> diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
> index a0801f68762b..7ec26d21303d 100644
> --- a/include/linux/perf/arm_pmu.h
> +++ b/include/linux/perf/arm_pmu.h
> @@ -187,5 +187,6 @@ void armpmu_free_irq(int irq, int cpu);
> #endif /* CONFIG_ARM_PMU */
>
> #define ARMV8_SPE_PDEV_NAME "arm,spe-v1"
> +#define ARMV8_TRBE_PDEV_NAME "arm-trbe-acpi"

Why is the TRBE name formatted differently to the SPE one?

Will

2023-08-02 01:19:44

by Anshuman Khandual

[permalink] [raw]
Subject: Re: [PATCH V2 2/4] arm_pmu: acpi: Add a representative platform device for TRBE



On 8/1/23 20:21, Will Deacon wrote:
> On Tue, Aug 01, 2023 at 03:10:50PM +0530, Anshuman Khandual wrote:
>> diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
>> index a0801f68762b..7ec26d21303d 100644
>> --- a/include/linux/perf/arm_pmu.h
>> +++ b/include/linux/perf/arm_pmu.h
>> @@ -187,5 +187,6 @@ void armpmu_free_irq(int irq, int cpu);
>> #endif /* CONFIG_ARM_PMU */
>>
>> #define ARMV8_SPE_PDEV_NAME "arm,spe-v1"
>> +#define ARMV8_TRBE_PDEV_NAME "arm-trbe-acpi"
>
> Why is the TRBE name formatted differently to the SPE one?

Nothing specific, although "arm,spe-v1" seemed more like a DT naming
scheme. But could change the name as "arm,trbe-v1" to be in sync with
SPE here.

2023-08-02 10:35:00

by Suzuki K Poulose

[permalink] [raw]
Subject: Re: [PATCH V2 2/4] arm_pmu: acpi: Add a representative platform device for TRBE

On 02/08/2023 02:07, Anshuman Khandual wrote:
>
>
> On 8/1/23 20:21, Will Deacon wrote:
>> On Tue, Aug 01, 2023 at 03:10:50PM +0530, Anshuman Khandual wrote:
>>> diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
>>> index a0801f68762b..7ec26d21303d 100644
>>> --- a/include/linux/perf/arm_pmu.h
>>> +++ b/include/linux/perf/arm_pmu.h
>>> @@ -187,5 +187,6 @@ void armpmu_free_irq(int irq, int cpu);
>>> #endif /* CONFIG_ARM_PMU */
>>>
>>> #define ARMV8_SPE_PDEV_NAME "arm,spe-v1"
>>> +#define ARMV8_TRBE_PDEV_NAME "arm-trbe-acpi"
>>
>> Why is the TRBE name formatted differently to the SPE one?
>
> Nothing specific, although "arm,spe-v1" seemed more like a DT naming
> scheme. But could change the name as "arm,trbe-v1" to be in sync with
> SPE here.

Do we really need v1 ? I would leave it as arm,trbe

Suzuki


2023-08-03 05:27:22

by Anshuman Khandual

[permalink] [raw]
Subject: Re: [PATCH V2 2/4] arm_pmu: acpi: Add a representative platform device for TRBE



On 8/2/23 15:41, Suzuki K Poulose wrote:
> On 02/08/2023 02:07, Anshuman Khandual wrote:
>>
>>
>> On 8/1/23 20:21, Will Deacon wrote:
>>> On Tue, Aug 01, 2023 at 03:10:50PM +0530, Anshuman Khandual wrote:
>>>> diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
>>>> index a0801f68762b..7ec26d21303d 100644
>>>> --- a/include/linux/perf/arm_pmu.h
>>>> +++ b/include/linux/perf/arm_pmu.h
>>>> @@ -187,5 +187,6 @@ void armpmu_free_irq(int irq, int cpu);
>>>>   #endif /* CONFIG_ARM_PMU */
>>>>     #define ARMV8_SPE_PDEV_NAME "arm,spe-v1"
>>>> +#define ARMV8_TRBE_PDEV_NAME "arm-trbe-acpi"
>>>
>>> Why is the TRBE name formatted differently to the SPE one?
>>
>> Nothing specific, although "arm,spe-v1" seemed more like a DT naming
>> scheme. But could change the name as "arm,trbe-v1" to be in sync with
>> SPE here.
>
> Do we really need v1 ? I would leave it as arm,trbe

Sure, will make it 'arm,trbe' instead.