Messages in this thread Patch in this message | | | From | Anshuman Khandual <> | Subject | [PATCH 1/3] arm_pmu: acpi: Add a representative platform device for TRBE | Date | Fri, 28 Jul 2023 16:57:31 +0530 |
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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 | 63 +++++++++++++++++++++++++++++++++++ include/linux/perf/arm_pmu.h | 1 + 3 files changed, 67 insertions(+)
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 90815ad762eb..dd3df6729808 100644 --- a/drivers/perf/arm_pmu_acpi.c +++ b/drivers/perf/arm_pmu_acpi.c @@ -139,6 +139,68 @@ static inline void arm_spe_acpi_register_device(void) } #endif /* CONFIG_ARM_SPE_PMU */ +#ifdef CONFIG_CORESIGHT_TRBE +static struct resource trbe_acpi_resources[] = { + { + /* irq */ + .flags = IORESOURCE_IRQ, + } +}; + +static struct platform_device trbe_acpi_dev = { + .name = ARMV8_TRBE_PDEV_NAME, + .id = -1, + .resource = trbe_acpi_resources, + .num_resources = ARRAY_SIZE(trbe_acpi_resources) +}; + +static void arm_trbe_acpi_register_device(void) +{ + int cpu, hetid, irq, ret; + bool first = true; + u16 gsi = 0; + + for_each_possible_cpu(cpu) { + struct acpi_madt_generic_interrupt *gicc; + + gicc = acpi_cpu_get_madt_gicc(cpu); + if (gicc->header.length < ACPI_MADT_GICC_TRBE) + return; + + if (first) { + gsi = gicc->trbe_interrupt; + if (!gsi) + return; + + hetid = find_acpi_cpu_topology_hetero_id(cpu); + first = false; + } else if ((gsi != gicc->trbe_interrupt) || + (hetid != find_acpi_cpu_topology_hetero_id(cpu))) { + pr_warn("ACPI: TRBE must be homogeneous\n"); + return; + } + } + + irq = acpi_register_gsi(NULL, gsi, ACPI_LEVEL_SENSITIVE, ACPI_ACTIVE_HIGH); + if (irq < 0) { + pr_warn("ACPI: TRBE Unable to register interrupt: %d\n", gsi); + return; + } + trbe_acpi_resources[0].start = irq; + + ret = platform_device_register(&trbe_acpi_dev); + if (ret < 0) { + pr_warn("ACPI: TRBE: Unable to register device\n"); + acpi_unregister_gsi(gsi); + } +} +#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; @@ -374,6 +436,7 @@ 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
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