Re: [PATCH v9 16/21] irqchip: Add GICv2 specific ACPI boot support

[Grant Likely]

On Wed, 25 Feb 2015 16:39:56 +0800
, Hanjun Guo <hanjun.guo@xxxxxxxxxx>
 wrote:
> From: Tomasz Nowicki <tomasz.nowicki@xxxxxxxxxx>
> 
> 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/virtualization
> extension, GICv3/4 and its ITS are considered as next steps.
> 
> CC: Jason Cooper <jason@xxxxxxxxxxxxxx>
> CC: Marc Zyngier <marc.zyngier@xxxxxxx>
> CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
> Tested-by: Yijing Wang <wangyijing@xxxxxxxxxx>
> Tested-by: Mark Langsdorf <mlangsdo@xxxxxxxxxx>
> Tested-by: Jon Masters <jcm@xxxxxxxxxx>
> Tested-by: Timur Tabi <timur@xxxxxxxxxxxxxx>
> Tested-by: Robert Richter <rrichter@xxxxxxxxxx>
> Acked-by: Robert Richter <rrichter@xxxxxxxxxx>
> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@xxxxxxxxxx>
> Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>

Reviewed-by: Grant Likely <grant.likely@xxxxxxxxxx>

> ---
>  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                 |  14 +++++
>  include/linux/irqchip/arm-gic-acpi.h |  29 ++++++++++
>  6 files changed, 175 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 9a23369..a720a61 100644
> --- a/arch/arm64/include/asm/acpi.h
> +++ b/arch/arm64/include/asm/acpi.h
> @@ -13,6 +13,8 @@
>  #define _ASM_ACPI_H
>  
>  #include <linux/mm.h>
> +#include <linux/irqchip/arm-gic-acpi.h>
> +
>  #include <asm/cputype.h>
>  #include <asm/smp_plat.h>
>  
> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> index 31f080e..af308c3 100644
> --- a/arch/arm64/kernel/acpi.c
> +++ b/arch/arm64/kernel/acpi.c
> @@ -359,3 +359,28 @@ void __init acpi_boot_table_init(void)
>  		pr_err("Can't find FADT\n");
>  	}
>  }
> +
> +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);
> +}
> diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
> index 4634cf7..929d668 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>
> @@ -1086,3 +1088,103 @@ 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 __initdata;
> +
> +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;
> +	static int cpu_base_assigned;
> +
> +	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 c03d8d1..e27117a 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -557,6 +557,20 @@ static inline int acpi_device_modalias(struct device *dev,
>  
>  #endif	/* !CONFIG_ACPI */
>  
> +#if defined(CONFIG_ACPI) && defined(CONFIG_ARM64)
> +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();
> +}
> +#else
> +static inline void acpi_irq_init(void) { }
> +#endif
> +
>  #ifdef CONFIG_ACPI
>  void acpi_os_set_prepare_sleep(int (*func)(u8 sleep_state,
>  			       u32 pm1a_ctrl,  u32 pm1b_ctrl));
> diff --git a/include/linux/irqchip/arm-gic-acpi.h b/include/linux/irqchip/arm-gic-acpi.h
> new file mode 100644
> index 0000000..d5b2c79
> --- /dev/null
> +++ b/include/linux/irqchip/arm-gic-acpi.h
> @@ -0,0 +1,29 @@
> +/*
> + * Copyright (C) 2014, Linaro Ltd.
> + *	Author: Tomasz Nowicki <tomasz.nowicki@xxxxxxxxxx>
> + *
> + * 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;
> +
> +int gic_v2_acpi_init(struct acpi_table_header *table);
> +void acpi_gic_init(void);
> +#endif
> +
> +#endif /* ARM_GIC_ACPI_H_ */
> -- 
> 1.9.1
> 

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