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

From: [email-masked] (Tomasz Nowicki)
Date: Tue, 03 Feb 2015 16:38:12 +0100

On 02.02.2015 13:45, Hanjun Guo wrote:
> From: Tomasz Nowicki <[email-masked]>
>
> 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 <[email-masked]>
> CC: Marc Zyngier <[email-masked]>
> Tested-by: Suravee Suthikulpanit <[email-masked]>
> Tested-by: Yijing Wang <[email-masked]>
> Tested-by: Mark Langsdorf <[email-masked]>
> Tested-by: Jon Masters <[email-masked]>
> Tested-by: Timur Tabi <[email-masked]>
> Signed-off-by: Tomasz Nowicki <[email-masked]>
> Signed-off-by: Hanjun Guo <[email-masked]>
> ---
>   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;

I just realized this will not work for !CONFIG_ARM64 case. Instead, it 
should be:

@@ -564,6 +549,23 @@ 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)
+{
+       return;
+}
+#endif
+
  #ifdef CONFIG_ACPI
  void acpi_os_set_prepare_sleep(int (*func)(u8 sleep_state,
                                u32 pm1a_ctrl,  u32 pm1b_ctrl));

Regards,
Tomasz