Commit d60fc389 authored by Tomasz Nowicki's avatar Tomasz Nowicki Committed by Will Deacon
Browse files

irqchip: Add GICv2 specific ACPI boot support 



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@lakedaemon.net>
CC: Marc Zyngier <marc.zyngier@arm.com>
CC: Thomas Gleixner <tglx@linutronix.de>
Tested-by: default avatarSuravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Tested-by: default avatarYijing Wang <wangyijing@huawei.com>
Tested-by: default avatarMark Langsdorf <mlangsdo@redhat.com>
Tested-by: default avatarJon Masters <jcm@redhat.com>
Tested-by: default avatarTimur Tabi <timur@codeaurora.org>
Tested-by: default avatarRobert Richter <rrichter@cavium.com>
Acked-by: default avatarRobert Richter <rrichter@cavium.com>
Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Acked-by: default avatarJason Cooper <jason@lakedaemon.net>
Reviewed-by: default avatarGrant Likely <grant.likely@linaro.org>
Signed-off-by: default avatarTomasz Nowicki <tomasz.nowicki@linaro.org>
Signed-off-by: default avatarHanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent fbe61ec7

arch/arm64/include/asm/acpi.h

+2 −0
Original line number Diff line number Diff line
@@ -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>

arch/arm64/include/asm/irq.h

+13 −0
Original line number Diff line number Diff line 
#ifndef __ASM_IRQ_H

#define __ASM_IRQ_H



#include <linux/irqchip/arm-gic-acpi.h>



#include <asm-generic/irq.h>



struct pt_regs;
@@ -8,4 +10,15 @@ struct pt_regs; 
extern void migrate_irqs(void);

extern void set_handle_irq(void (*handle_irq)(struct pt_regs *));



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();

}

#define acpi_irq_init acpi_irq_init



#endif

arch/arm64/kernel/acpi.c

+25 −0
Original line number Diff line number Diff line
@@ -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);

}

drivers/irqchip/irq-gic.c

+102 −0
Original line number Diff line number Diff line
@@ -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>
@@ -1090,3 +1092,103 @@ 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

drivers/irqchip/irqchip.c

+3 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
 * warranty of any kind, whether express or implied.

 */



#include <linux/acpi_irq.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();

}

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