ACPI 6.3 adds additional fields to the MADT GICC structure to describe SPE PPI's. We pick these out of the cached reference to the madt_gicc structure similarly to the core PMU code. We then create a platform device referring to the IRQ and let the user/module loader decide whether to load the SPE driver.
Tested-by: Hanjun Gou <[email protected]> Reviewed-by: Sudeep Holla <[email protected]> Reviewed-by: Lorenzo Pieralisi <[email protected]> Signed-off-by: Jeremy Linton <[email protected]> --- arch/arm64/include/asm/acpi.h | 3 ++ drivers/perf/arm_pmu_acpi.c | 72 +++++++++++++++++++++++++++++++++++ include/linux/perf/arm_pmu.h | 2 + 3 files changed, 77 insertions(+) diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h index ada0bc480a1b..b263e239cb59 100644 --- a/arch/arm64/include/asm/acpi.h +++ b/arch/arm64/include/asm/acpi.h @@ -38,6 +38,9 @@ (!(entry) || (entry)->header.length < ACPI_MADT_GICC_MIN_LENGTH || \ (unsigned long)(entry) + (entry)->header.length > (end)) +#define ACPI_MADT_GICC_SPE (ACPI_OFFSET(struct acpi_madt_generic_interrupt, \ + spe_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 d2c2978409d2..acce8781c456 100644 --- a/drivers/perf/arm_pmu_acpi.c +++ b/drivers/perf/arm_pmu_acpi.c @@ -71,6 +71,76 @@ static void arm_pmu_acpi_unregister_irq(int cpu) acpi_unregister_gsi(gsi); } +#if IS_ENABLED(CONFIG_ARM_SPE_PMU) +static struct resource spe_resources[] = { + { + /* irq */ + .flags = IORESOURCE_IRQ, + } +}; + +static struct platform_device spe_dev = { + .name = ARMV8_SPE_PDEV_NAME, + .id = -1, + .resource = spe_resources, + .num_resources = ARRAY_SIZE(spe_resources) +}; + +/* + * For lack of a better place, hook the normal PMU MADT walk + * and create a SPE device if we detect a recent MADT with + * a homogeneous PPI mapping. + */ +static void arm_spe_acpi_register_device(void) +{ + int cpu, hetid, irq, ret; + bool first = true; + u16 gsi = 0; + + /* + * Sanity check all the GICC tables for the same interrupt number. + * For now, we only support homogeneous ACPI/SPE machines. + */ + 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_SPE) + return; + + if (first) { + gsi = gicc->spe_interrupt; + if (!gsi) + return; + hetid = find_acpi_cpu_topology_hetero_id(cpu); + first = false; + } else if ((gsi != gicc->spe_interrupt) || + (hetid != find_acpi_cpu_topology_hetero_id(cpu))) { + pr_warn("ACPI: SPE must be homogeneous\n"); + return; + } + } + + irq = acpi_register_gsi(NULL, gsi, ACPI_LEVEL_SENSITIVE, + ACPI_ACTIVE_HIGH); + if (irq < 0) { + pr_warn("ACPI: SPE Unable to register interrupt: %d\n", gsi); + return; + } + + spe_resources[0].start = irq; + ret = platform_device_register(&spe_dev); + if (ret < 0) { + pr_warn("ACPI: SPE: Unable to register device\n"); + acpi_unregister_gsi(gsi); + } +} +#else +static inline void arm_spe_acpi_register_device(void) +{ +} +#endif /* CONFIG_ARM_SPE_PMU */ + static int arm_pmu_acpi_parse_irqs(void) { int irq, cpu, irq_cpu, err; @@ -276,6 +346,8 @@ static int arm_pmu_acpi_init(void) if (acpi_disabled) return 0; + arm_spe_acpi_register_device(); + ret = arm_pmu_acpi_parse_irqs(); if (ret) return ret; diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h index a9b0ee408fbd..71f525a35ac2 100644 --- a/include/linux/perf/arm_pmu.h +++ b/include/linux/perf/arm_pmu.h @@ -171,4 +171,6 @@ void armpmu_free_irq(int irq, int cpu); #endif /* CONFIG_ARM_PMU */ +#define ARMV8_SPE_PDEV_NAME "arm,spe-v1" + #endif /* __ARM_PMU_H__ */ -- 2.21.0
