Messages in this thread | | | Date | Fri, 4 Aug 2023 15:31:24 +0530 | Subject | Re: [PATCH V3 2/4] arm_pmu: acpi: Add a representative platform device for TRBE | From | Anshuman Khandual <> |
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On 8/3/23 11:26, Anshuman Khandual wrote: > 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: Anshuman Khandual <anshuman.khandual@arm.com> > --- > 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 235c14766a36..79feea548e6e 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)
Rather than adding IS_ENABLED() checks for all applicable configs in future which will need to call arm_acpi_register_pmu_device() for a dummy platform device, could we instead just add __maybe_unused for the function to prevent build warning when there are no call sites ? Seems bit better and simpler.
> static int > arm_acpi_register_pmu_device(struct platform_device *pdev, u8 len, > u16 (*parse_gsi)(struct acpi_madt_generic_interrupt *)) > @@ -166,6 +166,40 @@ 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; > @@ -401,6 +435,7 @@ 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..143fbc10ecfe 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" > > #endif /* __ARM_PMU_H__ */
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