[PATCH v8 16/21] irqchip: Add GICv2 specific ACPI boot support

Rafael J. Wysocki
2015-02-02T22:23:06Z

On Monday, February 02, 2015 08:45:44 PM Hanjun Guo wrote:
> From: Tomasz Nowicki <tomasz.nowicki@linaro.org>
>
> ACPI kernel uses MADT table for proper GIC initialization. It needs to
> parse GIC related subtables, collect CPU interface and distributor
> addresses and call driver initialization function (which is hardware
> abstraction agnostic). In a similar way, FDT initialize GICv1/2.
>
> NOTE: This commit allow to initialize GICv1/2 basic functionality.
> While now simple GICv2 init call is used, any further GIC features
> require generic infrastructure for proper ACPI irqchip initialization.
> That mechanism and stacked irqdomains to support GICv2 MSI/vitalization
> extension, GICv3/4 and its ITS are considered as next steps.
>
> CC: Jason Cooper <jason@lakedaemon.net>
> CC: Marc Zyngier <marc.zyngier@arm.com>
> Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
> Tested-by: Yijing Wang <wangyijing@huawei.com>
> Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
> Tested-by: Jon Masters <jcm@redhat.com>
> Tested-by: Timur Tabi <timur@codeaurora.org>
> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>

An ACK from Thomas Gleixner is absolutely necessary for anything touching
drivers/irqchip/.

> ---
> arch/arm64/include/asm/acpi.h | 2 +
> arch/arm64/kernel/acpi.c | 25 +++++++++
> drivers/irqchip/irq-gic.c | 102 +++++++++++++++++++++++++++++++++++
> drivers/irqchip/irqchip.c | 3 ++
> include/linux/acpi.h | 15 ++++++
> include/linux/irqchip/arm-gic-acpi.h | 31 +++++++++++
> 6 files changed, 178 insertions(+)
> create mode 100644 include/linux/irqchip/arm-gic-acpi.h
>
> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
> index 7e825b9..ea4d2b3 100644
> --- a/arch/arm64/include/asm/acpi.h
> +++ b/arch/arm64/include/asm/acpi.h
> @@ -12,6 +12,8 @@
> #ifndef _ASM_ACPI_H
> #define _ASM_ACPI_H
>
> +#include <linux/irqchip/arm-gic-acpi.h>
> +
> #include <asm/smp_plat.h>
>
> /* Basic configuration for ACPI */
> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> index f86a982..437315e 100644
> --- a/arch/arm64/kernel/acpi.c
> +++ b/arch/arm64/kernel/acpi.c
> @@ -319,6 +319,31 @@ void __init acpi_boot_table_init(void)
> }
> }
>
> +void __init acpi_gic_init(void)
> +{
> + struct acpi_table_header *table;
> + acpi_status status;
> + acpi_size tbl_size;
> + int err;
> +
> + if (acpi_disabled)
> + return;
> +
> + status = acpi_get_table_with_size(ACPI_SIG_MADT, 0, &table, &tbl_size);
> + if (ACPI_FAILURE(status)) {
> + const char *msg = acpi_format_exception(status);
> +
> + pr_err("Failed to get MADT table, %s\n", msg);
> + return;
> + }
> +
> + err = gic_v2_acpi_init(table);
> + if (err)
> + pr_err("Failed to initialize GIC IRQ controller");
> +
> + early_acpi_os_unmap_memory((char *)table, tbl_size);
> +}
> +
> static int __init parse_acpi(char *arg)
> {
> if (!arg)
> diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
> index d617ee5..7f874d6 100644
> --- a/drivers/irqchip/irq-gic.c
> +++ b/drivers/irqchip/irq-gic.c
> @@ -33,12 +33,14 @@
> #include <linux/of.h>
> #include <linux/of_address.h>
> #include <linux/of_irq.h>
> +#include <linux/acpi.h>
> #include <linux/irqdomain.h>
> #include <linux/interrupt.h>
> #include <linux/percpu.h>
> #include <linux/slab.h>
> #include <linux/irqchip/chained_irq.h>
> #include <linux/irqchip/arm-gic.h>
> +#include <linux/irqchip/arm-gic-acpi.h>
>
> #include <asm/cputype.h>
> #include <asm/irq.h>
> @@ -1083,3 +1085,103 @@ IRQCHIP_DECLARE(msm_8660_qgic, "qcom,msm-8660-qgic", gic_of_init);
> IRQCHIP_DECLARE(msm_qgic2, "qcom,msm-qgic2", gic_of_init);
>
> #endif
> +
> +#ifdef CONFIG_ACPI
> +static phys_addr_t dist_phy_base, cpu_phy_base;
> +static int cpu_base_assigned;
> +
> +static int __init
> +gic_acpi_parse_madt_cpu(struct acpi_subtable_header *header,
> + const unsigned long end)
> +{
> + struct acpi_madt_generic_interrupt *processor;
> + phys_addr_t gic_cpu_base;
> +
> + processor = (struct acpi_madt_generic_interrupt *)header;
> +
> + if (BAD_MADT_ENTRY(processor, end))
> + return -EINVAL;
> +
> + /*
> + * There is no support for non-banked GICv1/2 register in ACPI spec.
> + * All CPU interface addresses have to be the same.
> + */
> + gic_cpu_base = processor->base_address;
> + if (cpu_base_assigned && gic_cpu_base != cpu_phy_base)
> + return -EINVAL;
> +
> + cpu_phy_base = gic_cpu_base;
> + cpu_base_assigned = 1;
> + return 0;
> +}
> +
> +static int __init
> +gic_acpi_parse_madt_distributor(struct acpi_subtable_header *header,
> + const unsigned long end)
> +{
> + struct acpi_madt_generic_distributor *dist;
> +
> + dist = (struct acpi_madt_generic_distributor *)header;
> +
> + if (BAD_MADT_ENTRY(dist, end))
> + return -EINVAL;
> +
> + dist_phy_base = dist->base_address;
> + return 0;
> +}
> +
> +int __init
> +gic_v2_acpi_init(struct acpi_table_header *table)
> +{
> + void __iomem *cpu_base, *dist_base;
> + int count;
> +
> + /* Collect CPU base addresses */
> + count = acpi_parse_entries(ACPI_SIG_MADT,
> + sizeof(struct acpi_table_madt),
> + gic_acpi_parse_madt_cpu, table,
> + ACPI_MADT_TYPE_GENERIC_INTERRUPT, 0);
> + if (count <= 0) {
> + pr_err("No valid GICC entries exist\n");
> + return -EINVAL;
> + }
> +
> + /*
> + * Find distributor base address. We expect one distributor entry since
> + * ACPI 5.1 spec neither support multi-GIC instances nor GIC cascade.
> + */
> + count = acpi_parse_entries(ACPI_SIG_MADT,
> + sizeof(struct acpi_table_madt),
> + gic_acpi_parse_madt_distributor, table,
> + ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR, 0);
> + if (count <= 0) {
> + pr_err("No valid GICD entries exist\n");
> + return -EINVAL;
> + } else if (count > 1) {
> + pr_err("More than one GICD entry detected\n");
> + return -EINVAL;
> + }
> +
> + cpu_base = ioremap(cpu_phy_base, ACPI_GIC_CPU_IF_MEM_SIZE);
> + if (!cpu_base) {
> + pr_err("Unable to map GICC registers\n");
> + return -ENOMEM;
> + }
> +
> + dist_base = ioremap(dist_phy_base, ACPI_GICV2_DIST_MEM_SIZE);
> + if (!dist_base) {
> + pr_err("Unable to map GICD registers\n");
> + iounmap(cpu_base);
> + return -ENOMEM;
> + }
> +
> + /*
> + * Initialize zero GIC instance (no multi-GIC support). Also, set GIC
> + * as default IRQ domain to allow for GSI registration and GSI to IRQ
> + * number translation (see acpi_register_gsi() and acpi_gsi_to_irq()).
> + */
> + gic_init_bases(0, -1, dist_base, cpu_base, 0, NULL);
> + irq_set_default_host(gic_data[0].domain);
> + return 0;
> +}
> +#endif
> diff --git a/drivers/irqchip/irqchip.c b/drivers/irqchip/irqchip.c
> index 0fe2f71..5855240 100644
> --- a/drivers/irqchip/irqchip.c
> +++ b/drivers/irqchip/irqchip.c
> @@ -8,6 +8,7 @@
> * warranty of any kind, whether express or implied.
> */
>
> +#include <linux/acpi.h>
> #include <linux/init.h>
> #include <linux/of_irq.h>
> #include <linux/irqchip.h>
> @@ -26,4 +27,6 @@ extern struct of_device_id __irqchip_of_table[];
> void __init irqchip_init(void)
> {
> of_irq_init(__irqchip_of_table);
> +
> + acpi_irq_init();
> }
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 87f365e..536991b 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -162,6 +162,16 @@ extern u32 acpi_irq_not_handled;
> extern int sbf_port;
> extern unsigned long acpi_realmode_flags;
>
> +static inline void acpi_irq_init(void)
> +{
> + /*
> + * Hardcode ACPI IRQ chip initialization to GICv2 for now.
> + * Proper irqchip infrastructure will be implemented along with
> + * incoming GICv2m|GICv3|ITS bits.
> + */
> + acpi_gic_init();
> +}
> +
> int acpi_register_gsi (struct device *dev, u32 gsi, int triggering, int polarity);
> int acpi_gsi_to_irq (u32 gsi, unsigned int *irq);
> int acpi_isa_irq_to_gsi (unsigned isa_irq, u32 *gsi);
> @@ -508,6 +518,11 @@ static inline int acpi_table_parse(char *id,
> return -ENODEV;
> }
>
> +static inline void acpi_irq_init(void)
> +{
> + return;
> +}
> +
> static inline int acpi_nvs_register(__u64 start, __u64 size)
> {
> return 0;
> diff --git a/include/linux/irqchip/arm-gic-acpi.h b/include/linux/irqchip/arm-gic-acpi.h
> new file mode 100644
> index 0000000..ad5b577
> --- /dev/null
> +++ b/include/linux/irqchip/arm-gic-acpi.h
> @@ -0,0 +1,31 @@
> +/*
> + * Copyright (C) 2014, Linaro Ltd.
> + * Author: Tomasz Nowicki <tomasz.nowicki@linaro.org>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#ifndef ARM_GIC_ACPI_H_
> +#define ARM_GIC_ACPI_H_
> +
> +#ifdef CONFIG_ACPI
> +
> +/*
> + * Hard code here, we can not get memory size from MADT (but FDT does),
> + * Actually no need to do that, because this size can be inferred
> + * from GIC spec.
> + */
> +#define ACPI_GICV2_DIST_MEM_SIZE (SZ_4K)
> +#define ACPI_GIC_CPU_IF_MEM_SIZE (SZ_8K)
> +
> +struct acpi_table_header;
> +
> +void acpi_gic_init(void);
> +int gic_v2_acpi_init(struct acpi_table_header *table);
> +#else
> +static inline void acpi_gic_init(void) { }
> +#endif
> +
> +#endif /* ARM_GIC_ACPI_H_ */
>

--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.