From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeremy Linton Subject: [PATCH 3/4] arm_pmu: acpi: spe: Add initial MADT/SPE probing Date: Tue, 26 Mar 2019 17:39:37 -0500 Message-ID: <20190326223938.5365-4-jeremy.linton@arm.com> References: <20190326223938.5365-1-jeremy.linton@arm.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190326223938.5365-1-jeremy.linton@arm.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-arm-kernel@lists.infradead.org Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, will.deacon@arm.com, rjw@rjwysocki.net, lenb@kernel.org, mark.rutland@arm.com, sudeep.holla@arm.com, james.morse@arm.com, lorenzo.pieralisi@arm.com, linuxarm@huawei.com, Jeremy Linton List-Id: linux-acpi@vger.kernel.org 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. Signed-off-by: Jeremy Linton --- arch/arm64/include/asm/acpi.h | 3 ++ drivers/perf/arm_pmu_acpi.c | 69 +++++++++++++++++++++++++++++++++++ 2 files changed, 72 insertions(+) diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h index 7628efbe6c12..d10399b9f998 100644 --- a/arch/arm64/include/asm/acpi.h +++ b/arch/arm64/include/asm/acpi.h @@ -41,6 +41,9 @@ (!(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 0f197516d708..a2418108eab2 100644 --- a/drivers/perf/arm_pmu_acpi.c +++ b/drivers/perf/arm_pmu_acpi.c @@ -74,6 +74,73 @@ static void arm_pmu_acpi_unregister_irq(int cpu) acpi_unregister_gsi(gsi); } +static struct resource spe_resources[] = { + { + /* irq */ + .flags = IORESOURCE_IRQ, + } +}; + +static struct platform_device spe_dev = { + .name = "arm,spe-v1", + .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 int arm_spe_acpi_parse_irqs(void) +{ + int cpu, ret, irq; + int hetid; + u16 gsi = 0; + bool first = true; + + struct acpi_madt_generic_interrupt *gicc; + + /* + * 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) { + gicc = acpi_cpu_get_madt_gicc(cpu); + + if (gicc->header.length < ACPI_MADT_GICC_SPE) + return -ENODEV; + if (first) { + gsi = gicc->spe_interrupt; + if (!gsi) + return -ENODEV; + 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 -EINVAL; + } + } + + 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 irq; + } + + 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); + } + + return ret; +} + static int arm_pmu_acpi_parse_irqs(void) { int irq, cpu, irq_cpu, err; @@ -279,6 +346,8 @@ static int arm_pmu_acpi_init(void) if (acpi_disabled) return 0; + arm_spe_acpi_parse_irqs(); /* failures are expected */ + ret = arm_pmu_acpi_parse_irqs(); if (ret) return ret; -- 2.20.1