Commit 1aa3d027 authored by Anshuman Khandual's avatar Anshuman Khandual Committed by Will Deacon
Browse files

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 <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: default avatarAnshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20230817055405.249630-3-anshuman.khandual@arm.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 81e5ee47

arch/arm64/include/asm/acpi.h

+3 −0
Original line number Diff line number Diff line
@@ -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);

drivers/perf/arm_pmu_acpi.c

+35 −0
Original line number Diff line number Diff line
@@ -163,6 +163,40 @@ static inline void arm_spe_acpi_register_device(void) 
}

#endif /* CONFIG_ARM_SPE_PMU */



#if IS_ENABLED(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;
@@ -398,6 +432,7 @@ static int arm_pmu_acpi_init(void) 
		return 0;



	arm_spe_acpi_register_device();

	arm_trbe_acpi_register_device();



	return 0;

}

include/linux/perf/arm_pmu.h

+1 −0
Original line number Diff line number Diff line
@@ -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"



#endif /* __ARM_PMU_H__ */