Re: [PATCH 1/5] ACPI: move arm64 GSI IRQ model to generic GSI IRQ layer

From: Marc Zyngier
Date: Wed Mar 25 2015 - 09:20:52 EST

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On 24/03/15 17:58, Lorenzo Pieralisi wrote:
> The code deployed to implement GSI linux IRQ numbers mapping on arm64 turns
> out to be generic enough so that it can be moved to ACPI core code along
> with its respective config option ACPI_GENERIC_GSI selectable on
> architectures that can reuse the same code.
>
> Current ACPI IRQ mapping code is not integrated in the kernel IRQ domain
> infrastructure, in particular there is no way to look-up the
> IRQ domain associated with a particular interrupt controller, so this
> first version of GSI generic code carries out the GSI<->IRQ mapping relying
> on the IRQ default domain which is supposed to be always set on a
> specific architecture in case the domain structure passed to
> irq_create/find_mapping() functions is missing.
>
> This patch moves the arm64 acpi functions that implement the gsi mappings:
>
> acpi_gsi_to_irq()
> acpi_register_gsi()
> acpi_unregister_gsi()
>
> to ACPI core code. Since the generic GSI<->domain mapping is based on IRQ
> domains, it can be extended as soon as a way to map an interrupt
> controller to an IRQ domain is implemented for ACPI in the IRQ domain
> layer.
>
> x86 and ia64 code for GSI mappings cannot rely on the generic GSI
> layer at present for legacy reasons, so they do not select the
> ACPI_GENERIC_GSI config options and keep relying on their arch
> specific GSI mapping layer.

This looks like the right thing to do. I definitely like the sanity
checking that has been added here.

FWIW: Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx>

M.

> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> Cc: Will Deacon <will.deacon@xxxxxxx>
> Cc: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> Cc: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>
> Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
> ---
> arch/arm64/Kconfig | 1 +
> arch/arm64/kernel/acpi.c | 73 --------------------------------
> drivers/acpi/Kconfig | 3 ++
> drivers/acpi/Makefile | 1 +
> drivers/acpi/gsi.c | 105 ++++++++++++++++++++++++++++++++++++++++++++++
> drivers/irqchip/irq-gic.c | 2 +
> 6 files changed, 112 insertions(+), 73 deletions(-)
> create mode 100644 drivers/acpi/gsi.c
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index e5aa081..0659db3 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -1,5 +1,6 @@
> config ARM64
> def_bool y
> + select ACPI_GENERIC_GSI if ACPI
> select ACPI_REDUCED_HARDWARE_ONLY if ACPI
> select ARCH_BINFMT_ELF_RANDOMIZE_PIE
> select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> index fe9d8f0..a70f714 100644
> --- a/arch/arm64/kernel/acpi.c
> +++ b/arch/arm64/kernel/acpi.c
> @@ -76,12 +76,6 @@ static int __init dt_scan_depth1_nodes(unsigned long node,
> }
>
> /*
> - * Since we're on ARM, the default interrupt routing model
> - * clearly has to be GIC.
> - */
> -enum acpi_irq_model_id acpi_irq_model = ACPI_IRQ_MODEL_GIC;
> -
> -/*
> * __acpi_map_table() will be called before page_init(), so early_ioremap()
> * or early_memremap() should be called here to for ACPI table mapping.
> */
> @@ -224,73 +218,6 @@ void __init acpi_init_cpus(void)
> pr_info("%d CPUs enabled, %d CPUs total\n", enabled_cpus, total_cpus);
> }
>
> -int acpi_gsi_to_irq(u32 gsi, unsigned int *irq)
> -{
> - *irq = irq_find_mapping(NULL, gsi);
> -
> - return 0;
> -}
> -EXPORT_SYMBOL_GPL(acpi_gsi_to_irq);
> -
> -/*
> - * success: return IRQ number (>0)
> - * failure: return =< 0
> - */
> -int acpi_register_gsi(struct device *dev, u32 gsi, int trigger, int polarity)
> -{
> - unsigned int irq;
> - unsigned int irq_type;
> -
> - /*
> - * ACPI have no bindings to indicate SPI or PPI, so we
> - * use different mappings from DT in ACPI.
> - *
> - * For FDT
> - * PPI interrupt: in the range [0, 15];
> - * SPI interrupt: in the range [0, 987];
> - *
> - * For ACPI, GSI should be unique so using
> - * the hwirq directly for the mapping:
> - * PPI interrupt: in the range [16, 31];
> - * SPI interrupt: in the range [32, 1019];
> - */
> -
> - if (trigger == ACPI_EDGE_SENSITIVE &&
> - polarity == ACPI_ACTIVE_LOW)
> - irq_type = IRQ_TYPE_EDGE_FALLING;
> - else if (trigger == ACPI_EDGE_SENSITIVE &&
> - polarity == ACPI_ACTIVE_HIGH)
> - irq_type = IRQ_TYPE_EDGE_RISING;
> - else if (trigger == ACPI_LEVEL_SENSITIVE &&
> - polarity == ACPI_ACTIVE_LOW)
> - irq_type = IRQ_TYPE_LEVEL_LOW;
> - else if (trigger == ACPI_LEVEL_SENSITIVE &&
> - polarity == ACPI_ACTIVE_HIGH)
> - irq_type = IRQ_TYPE_LEVEL_HIGH;
> - else
> - irq_type = IRQ_TYPE_NONE;
> -
> - /*
> - * Since only one GIC is supported in ACPI 5.0, we can
> - * create mapping refer to the default domain
> - */
> - irq = irq_create_mapping(NULL, gsi);
> - if (!irq)
> - return irq;
> -
> - /* Set irq type if specified and different than the current one */
> - if (irq_type != IRQ_TYPE_NONE &&
> - irq_type != irq_get_trigger_type(irq))
> - irq_set_irq_type(irq, irq_type);
> - return irq;
> -}
> -EXPORT_SYMBOL_GPL(acpi_register_gsi);
> -
> -void acpi_unregister_gsi(u32 gsi)
> -{
> -}
> -EXPORT_SYMBOL_GPL(acpi_unregister_gsi);
> -
> static int __init acpi_parse_fadt(struct acpi_table_header *table)
> {
> struct acpi_table_fadt *fadt = (struct acpi_table_fadt *)table;
> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> index a8f531e2..ab2cbb5 100644
> --- a/drivers/acpi/Kconfig
> +++ b/drivers/acpi/Kconfig
> @@ -48,6 +48,9 @@ config ACPI_LEGACY_TABLES_LOOKUP
> config ARCH_MIGHT_HAVE_ACPI_PDC
> bool
>
> +config ACPI_GENERIC_GSI
> + bool
> +
> config ACPI_SYSTEM_POWER_STATES_SUPPORT
> bool
>
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index db153c6..8a063e2 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -56,6 +56,7 @@ ifdef CONFIG_ACPI_VIDEO
> acpi-y += video_detect.o
> endif
> acpi-y += acpi_lpat.o
> +acpi-$(CONFIG_ACPI_GENERIC_GSI) += gsi.o
>
> # These are (potentially) separate modules
>
> diff --git a/drivers/acpi/gsi.c b/drivers/acpi/gsi.c
> new file mode 100644
> index 0000000..38208f2
> --- /dev/null
> +++ b/drivers/acpi/gsi.c
> @@ -0,0 +1,105 @@
> +/*
> + * ACPI GSI IRQ layer
> + *
> + * Copyright (C) 2015 ARM Ltd.
> + * Author: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> + *
> + * 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.
> + */
> +#include <linux/acpi.h>
> +#include <linux/irq.h>
> +#include <linux/irqdomain.h>
> +
> +enum acpi_irq_model_id acpi_irq_model;
> +
> +static unsigned int acpi_gsi_get_irq_type(int trigger, int polarity)
> +{
> + switch (polarity) {
> + case ACPI_ACTIVE_LOW:
> + return trigger == ACPI_EDGE_SENSITIVE ?
> + IRQ_TYPE_EDGE_FALLING :
> + IRQ_TYPE_LEVEL_LOW;
> + case ACPI_ACTIVE_HIGH:
> + return trigger == ACPI_EDGE_SENSITIVE ?
> + IRQ_TYPE_EDGE_RISING :
> + IRQ_TYPE_LEVEL_HIGH;
> + case ACPI_ACTIVE_BOTH:
> + if (trigger == ACPI_EDGE_SENSITIVE)
> + return IRQ_TYPE_EDGE_BOTH;
> + default:
> + return IRQ_TYPE_NONE;
> + }
> +}
> +
> +/**
> + * acpi_gsi_to_irq() - Retrieve the linux irq number for a given GSI
> + * @gsi: GSI IRQ number to map
> + * @irq: pointer where linux IRQ number is stored
> + *
> + * irq location updated with irq value [>0 on success, 0 on failure]
> + *
> + * Returns: linux IRQ number on success (>0)
> + * -EINVAL on failure
> + */
> +int acpi_gsi_to_irq(u32 gsi, unsigned int *irq)
> +{
> + /*
> + * Only default domain is supported at present, always find
> + * the mapping corresponding to default domain by passing NULL
> + * as irq_domain parameter
> + */
> + *irq = irq_find_mapping(NULL, gsi);
> + /*
> + * *irq == 0 means no mapping, that should
> + * be reported as a failure
> + */
> + return (*irq > 0) ? *irq : -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(acpi_gsi_to_irq);
> +
> +/**
> + * acpi_register_gsi() - Map a GSI to a linux IRQ number
> + * @dev: device for which IRQ has to be mapped
> + * @gsi: GSI IRQ number
> + * @trigger: trigger type of the GSI number to be mapped
> + * @polarity: polarity of the GSI to be mapped
> + *
> + * Returns: a valid linux IRQ number on success
> + * -EINVAL on failure
> + */
> +int acpi_register_gsi(struct device *dev, u32 gsi, int trigger,
> + int polarity)
> +{
> + unsigned int irq;
> + unsigned int irq_type = acpi_gsi_get_irq_type(trigger, polarity);
> +
> + /*
> + * There is no way at present to look-up the IRQ domain on ACPI,
> + * hence always create mapping referring to the default domain
> + * by passing NULL as irq_domain parameter
> + */
> + irq = irq_create_mapping(NULL, gsi);
> + if (!irq)
> + return -EINVAL;
> +
> + /* Set irq type if specified and different than the current one */
> + if (irq_type != IRQ_TYPE_NONE &&
> + irq_type != irq_get_trigger_type(irq))
> + irq_set_irq_type(irq, irq_type);
> + return irq;
> +}
> +EXPORT_SYMBOL_GPL(acpi_register_gsi);
> +
> +/**
> + * acpi_unregister_gsi() - Free a GSI<->linux IRQ number mapping
> + * @gsi: GSI IRQ number
> + */
> +void acpi_unregister_gsi(u32 gsi)
> +{
> + int irq = irq_find_mapping(NULL, gsi);
> +
> + irq_dispose_mapping(irq);
> +}
> +EXPORT_SYMBOL_GPL(acpi_unregister_gsi);
> diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
> index d15a36a..f1efb53 100644
> --- a/drivers/irqchip/irq-gic.c
> +++ b/drivers/irqchip/irq-gic.c
> @@ -1189,6 +1189,8 @@ gic_v2_acpi_init(struct acpi_table_header *table)
> */
> gic_init_bases(0, -1, dist_base, cpu_base, 0, NULL);
> irq_set_default_host(gic_data[0].domain);
> +
> + acpi_irq_model = ACPI_IRQ_MODEL_GIC;
> return 0;
> }
> #endif
>

--
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Next message: Mika Westerberg: "Re: [PATCH] IIO: Adds ACPI support for ST gyroscopes"
Previous message: Stephane Viau: "[PATCH] clk: qcom: gdsc: Add GDSCs in apq8084 MMCC"
In reply to: Lorenzo Pieralisi: "[PATCH 1/5] ACPI: move arm64 GSI IRQ model to generic GSI IRQ layer"
Next in thread: Lorenzo Pieralisi: "Re: [PATCH 1/5] ACPI: move arm64 GSI IRQ model to generic GSI IRQ layer"
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