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Message-ID: <4DFF18D0.3020901@arm.com>
Date: Mon, 20 Jun 2011 10:54:24 +0100
From: Marc Zyngier <marc.zyngier@....com>
To: Grant Likely <grant.likely@...retlab.ca>
CC: Nicolas Pitre <nicolas.pitre@...aro.org>,
Russell King <linux@....linux.org.uk>,
Arnd Bergmann <arnd@...db.de>,
"devicetree-discuss@...ts.ozlabs.org"
<devicetree-discuss@...ts.ozlabs.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"linux-arm-kernel@...ts.infradead.org"
<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [RFC PATCH 01/11] irq: add irq_domain translation infrastructure
On 16/06/11 05:41, Grant Likely wrote:
> This patch adds irq_domain infrastructure for translating from
> hardware irq numbers to linux irqs. This is particularly important
> for architectures adding device tree support because the current
> implementation (excluding PowerPC and SPARC) cannot handle
> translation for more than a single interrupt controller. irq_domain
> supports device tree translation for any number of interrupt
> controllers.
>
> This patch converts x86, Microblaze, ARM and MIPS to use irq_domain
> for device tree irq translation. x86 is untested beyond compiling it,
> and the patch definitely breaks MIPS and Microblaze because I haven't
> added the code to either of them to actually register an irq_domain
> yet (easy to fix), but on ARM it works. I'm circulating this for comments
> to make sure I'm on the right path before I fix up the MIPS and
> Microblaze bits.
>
> PowerPC has /not/ been converted to use this new infrastructure. It
> is still missing some features before it can replace the virq
> infrastructure already in powerpc (see documentation on
> irq_domain_map/unmap for details). Followup patches will add the
> missing pieces and migrate PowerPC to use irq_domain.
>
> SPARC has its own method of managing interrupts from the device tree
> and is unaffected by this change.
>
> Signed-off-by: Grant Likely <grant.likely@...retlab.ca>
I've rebased my PPI + local timer patches on top of that patch in
the following branch:
git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git ppi_irq_domain
This makes the code cleaner, though the way to link this into DT
is not completely clear for me yet.
Cheers,
M.
> ---
> arch/arm/include/asm/prom.h | 5 -
> arch/arm/kernel/devtree.c | 14 ---
> arch/microblaze/include/asm/irq.h | 10 --
> arch/microblaze/kernel/irq.c | 7 --
> arch/mips/include/asm/irq.h | 5 -
> arch/mips/kernel/prom.c | 14 ---
> arch/powerpc/include/asm/irq.h | 1
> arch/x86/include/asm/irq_controller.h | 12 ---
> arch/x86/include/asm/prom.h | 10 --
> arch/x86/kernel/devicetree.c | 101 ++++++++----------------
> include/linux/irq.h | 81 ++++++++++++++++++++
> include/linux/of_irq.h | 2
> kernel/irq/Makefile | 2
> kernel/irq/irqdomain.c | 137 +++++++++++++++++++++++++++++++++
> 14 files changed, 257 insertions(+), 144 deletions(-)
> delete mode 100644 arch/x86/include/asm/irq_controller.h
> create mode 100644 kernel/irq/irqdomain.c
>
> diff --git a/arch/arm/include/asm/prom.h b/arch/arm/include/asm/prom.h
> index 11b8708..6f65ca8 100644
> --- a/arch/arm/include/asm/prom.h
> +++ b/arch/arm/include/asm/prom.h
> @@ -16,11 +16,6 @@
> #include <asm/setup.h>
> #include <asm/irq.h>
>
> -static inline void irq_dispose_mapping(unsigned int virq)
> -{
> - return;
> -}
> -
> extern struct machine_desc *setup_machine_fdt(unsigned int dt_phys);
> extern void arm_dt_memblock_reserve(void);
>
> diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c
> index a701e42..1e0b613 100644
> --- a/arch/arm/kernel/devtree.c
> +++ b/arch/arm/kernel/devtree.c
> @@ -129,17 +129,3 @@ struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
>
> return mdesc_best;
> }
> -
> -/**
> - * irq_create_of_mapping - Hook to resolve OF irq specifier into a Linux irq#
> - *
> - * Currently the mapping mechanism is trivial; simple flat hwirq numbers are
> - * mapped 1:1 onto Linux irq numbers. Cascaded irq controllers are not
> - * supported.
> - */
> -unsigned int irq_create_of_mapping(struct device_node *controller,
> - const u32 *intspec, unsigned int intsize)
> -{
> - return intspec[0];
> -}
> -EXPORT_SYMBOL_GPL(irq_create_of_mapping);
> diff --git a/arch/microblaze/include/asm/irq.h b/arch/microblaze/include/asm/irq.h
> index cc54187..6a6d83b 100644
> --- a/arch/microblaze/include/asm/irq.h
> +++ b/arch/microblaze/include/asm/irq.h
> @@ -16,6 +16,7 @@
> * be big enough to enclose whatever representation is used by a given
> * platform.
> */
> +#define _IRQ_HW_NUMBER_T
> typedef unsigned long irq_hw_number_t;
>
> extern unsigned int nr_irq;
> @@ -25,15 +26,6 @@ extern unsigned int nr_irq;
> struct pt_regs;
> extern void do_IRQ(struct pt_regs *regs);
>
> -/** FIXME - not implement
> - * irq_dispose_mapping - Unmap an interrupt
> - * @virq: linux virq number of the interrupt to unmap
> - */
> -static inline void irq_dispose_mapping(unsigned int virq)
> -{
> - return;
> -}
> -
> struct irq_host;
>
> /**
> diff --git a/arch/microblaze/kernel/irq.c b/arch/microblaze/kernel/irq.c
> index ce7ac84..59bb560 100644
> --- a/arch/microblaze/kernel/irq.c
> +++ b/arch/microblaze/kernel/irq.c
> @@ -54,10 +54,3 @@ unsigned int irq_create_mapping(struct irq_host *host, irq_hw_number_t hwirq)
> return hwirq;
> }
> EXPORT_SYMBOL_GPL(irq_create_mapping);
> -
> -unsigned int irq_create_of_mapping(struct device_node *controller,
> - const u32 *intspec, unsigned int intsize)
> -{
> - return intspec[0];
> -}
> -EXPORT_SYMBOL_GPL(irq_create_of_mapping);
> diff --git a/arch/mips/include/asm/irq.h b/arch/mips/include/asm/irq.h
> index 0ec0129..dc650ae 100644
> --- a/arch/mips/include/asm/irq.h
> +++ b/arch/mips/include/asm/irq.h
> @@ -16,11 +16,6 @@
>
> #include <irq.h>
>
> -static inline void irq_dispose_mapping(unsigned int virq)
> -{
> - return;
> -}
> -
> #ifdef CONFIG_I8259
> static inline int irq_canonicalize(int irq)
> {
> diff --git a/arch/mips/kernel/prom.c b/arch/mips/kernel/prom.c
> index 5b7eade..010aaaf 100644
> --- a/arch/mips/kernel/prom.c
> +++ b/arch/mips/kernel/prom.c
> @@ -60,20 +60,6 @@ void __init early_init_dt_setup_initrd_arch(unsigned long start,
> }
> #endif
>
> -/*
> - * irq_create_of_mapping - Hook to resolve OF irq specifier into a Linux irq#
> - *
> - * Currently the mapping mechanism is trivial; simple flat hwirq numbers are
> - * mapped 1:1 onto Linux irq numbers. Cascaded irq controllers are not
> - * supported.
> - */
> -unsigned int irq_create_of_mapping(struct device_node *controller,
> - const u32 *intspec, unsigned int intsize)
> -{
> - return intspec[0];
> -}
> -EXPORT_SYMBOL_GPL(irq_create_of_mapping);
> -
> void __init early_init_devtree(void *params)
> {
> /* Setup flat device-tree pointer */
> diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h
> index 1bff591..66bf09e 100644
> --- a/arch/powerpc/include/asm/irq.h
> +++ b/arch/powerpc/include/asm/irq.h
> @@ -45,6 +45,7 @@ extern atomic_t ppc_n_lost_interrupts;
> * be big enough to enclose whatever representation is used by a given
> * platform.
> */
> +#define _IRQ_HW_NUMBER_T
> typedef unsigned long irq_hw_number_t;
>
> /* Interrupt controller "host" data structure. This could be defined as a
> diff --git a/arch/x86/include/asm/irq_controller.h b/arch/x86/include/asm/irq_controller.h
> deleted file mode 100644
> index 423bbbd..0000000
> --- a/arch/x86/include/asm/irq_controller.h
> +++ /dev/null
> @@ -1,12 +0,0 @@
> -#ifndef __IRQ_CONTROLLER__
> -#define __IRQ_CONTROLLER__
> -
> -struct irq_domain {
> - int (*xlate)(struct irq_domain *h, const u32 *intspec, u32 intsize,
> - u32 *out_hwirq, u32 *out_type);
> - void *priv;
> - struct device_node *controller;
> - struct list_head l;
> -};
> -
> -#endif
> diff --git a/arch/x86/include/asm/prom.h b/arch/x86/include/asm/prom.h
> index 971e0b4..2c8101e 100644
> --- a/arch/x86/include/asm/prom.h
> +++ b/arch/x86/include/asm/prom.h
> @@ -21,7 +21,6 @@
> #include <asm/irq.h>
> #include <asm/atomic.h>
> #include <asm/setup.h>
> -#include <asm/irq_controller.h>
>
> #ifdef CONFIG_OF
> extern int of_ioapic;
> @@ -54,15 +53,6 @@ extern char cmd_line[COMMAND_LINE_SIZE];
> #define pci_address_to_pio pci_address_to_pio
> unsigned long pci_address_to_pio(phys_addr_t addr);
>
> -/**
> - * irq_dispose_mapping - Unmap an interrupt
> - * @virq: linux virq number of the interrupt to unmap
> - *
> - * FIXME: We really should implement proper virq handling like power,
> - * but that's going to be major surgery.
> - */
> -static inline void irq_dispose_mapping(unsigned int virq) { }
> -
> #define HAVE_ARCH_DEVTREE_FIXUPS
>
> #endif /* __ASSEMBLY__ */
> diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
> index 9aeb78a..250c2d5 100644
> --- a/arch/x86/kernel/devicetree.c
> +++ b/arch/x86/kernel/devicetree.c
> @@ -16,64 +16,14 @@
> #include <linux/initrd.h>
>
> #include <asm/hpet.h>
> -#include <asm/irq_controller.h>
> #include <asm/apic.h>
> #include <asm/pci_x86.h>
>
> __initdata u64 initial_dtb;
> char __initdata cmd_line[COMMAND_LINE_SIZE];
> -static LIST_HEAD(irq_domains);
> -static DEFINE_RAW_SPINLOCK(big_irq_lock);
>
> int __initdata of_ioapic;
>
> -#ifdef CONFIG_X86_IO_APIC
> -static void add_interrupt_host(struct irq_domain *ih)
> -{
> - unsigned long flags;
> -
> - raw_spin_lock_irqsave(&big_irq_lock, flags);
> - list_add(&ih->l, &irq_domains);
> - raw_spin_unlock_irqrestore(&big_irq_lock, flags);
> -}
> -#endif
> -
> -static struct irq_domain *get_ih_from_node(struct device_node *controller)
> -{
> - struct irq_domain *ih, *found = NULL;
> - unsigned long flags;
> -
> - raw_spin_lock_irqsave(&big_irq_lock, flags);
> - list_for_each_entry(ih, &irq_domains, l) {
> - if (ih->controller == controller) {
> - found = ih;
> - break;
> - }
> - }
> - raw_spin_unlock_irqrestore(&big_irq_lock, flags);
> - return found;
> -}
> -
> -unsigned int irq_create_of_mapping(struct device_node *controller,
> - const u32 *intspec, unsigned int intsize)
> -{
> - struct irq_domain *ih;
> - u32 virq, type;
> - int ret;
> -
> - ih = get_ih_from_node(controller);
> - if (!ih)
> - return 0;
> - ret = ih->xlate(ih, intspec, intsize, &virq, &type);
> - if (ret)
> - return 0;
> - if (type == IRQ_TYPE_NONE)
> - return virq;
> - irq_set_irq_type(virq, type);
> - return virq;
> -}
> -EXPORT_SYMBOL_GPL(irq_create_of_mapping);
> -
> unsigned long pci_address_to_pio(phys_addr_t address)
> {
> /*
> @@ -377,36 +327,49 @@ static struct of_ioapic_type of_ioapic_type[] =
> },
> };
>
> -static int ioapic_xlate(struct irq_domain *id, const u32 *intspec, u32 intsize,
> - u32 *out_hwirq, u32 *out_type)
> +static int ioapic_dt_translate(struct irq_domain *domain,
> + struct device_node *controller,
> + const u32 *intspec, u32 intsize,
> + irq_hw_number_t *out_hwirq, u32 *out_type)
> {
> - struct mp_ioapic_gsi *gsi_cfg;
> struct io_apic_irq_attr attr;
> struct of_ioapic_type *it;
> u32 line, idx, type;
> + int rc;
>
> - if (intsize < 2)
> + if (controller != domain->of_node)
> return -EINVAL;
>
> - line = *intspec;
> - idx = (u32) id->priv;
> - gsi_cfg = mp_ioapic_gsi_routing(idx);
> - *out_hwirq = line + gsi_cfg->gsi_base;
> + if (intsize < 2)
> + return -EINVAL;
>
> - intspec++;
> - type = *intspec;
> + line = intspec[0];
>
> - if (type >= ARRAY_SIZE(of_ioapic_type))
> + if (intspec[1] >= ARRAY_SIZE(of_ioapic_type))
> return -EINVAL;
>
> - it = of_ioapic_type + type;
> - *out_type = it->out_type;
> + it = of_ioapic_type + intspec[1];
> + type = it->out_type;
>
> + idx = (u32) domain->priv;
> set_io_apic_irq_attr(&attr, idx, line, it->trigger, it->polarity);
>
> - return io_apic_setup_irq_pin_once(*out_hwirq, cpu_to_node(0), &attr);
> + rc = io_apic_setup_irq_pin_once(irq_domain_to_irq(domain, line),
> + cpu_to_node(0), &attr);
> + if (rc)
> + return rc;
> +
> + if (out_hwirq)
> + *out_hwirq = line;
> + if (out_type)
> + *out_type = type;
> + return 0;
> }
>
> +const struct irq_domain_ops ioapic_irq_domain_ops = {
> + .dt_translate = ioapic_dt_translate,
> +};
> +
> static void __init ioapic_add_ofnode(struct device_node *np)
> {
> struct resource r;
> @@ -422,13 +385,17 @@ static void __init ioapic_add_ofnode(struct device_node *np)
> for (i = 0; i < nr_ioapics; i++) {
> if (r.start == mpc_ioapic_addr(i)) {
> struct irq_domain *id;
> + struct mp_ioapic_gsi *gsi_cfg;
> +
> + gsi_cfg = mp_ioapic_gsi_routing(i);
>
> id = kzalloc(sizeof(*id), GFP_KERNEL);
> BUG_ON(!id);
> - id->controller = np;
> - id->xlate = ioapic_xlate;
> + id->ops = &ioapic_irq_domain_ops;
> + id->irq_base = gsi_cfg->gsi_base;
> + id->of_node = np;
> id->priv = (void *)i;
> - add_interrupt_host(id);
> + irq_domain_add(id);
> return;
> }
> }
> diff --git a/include/linux/irq.h b/include/linux/irq.h
> index 8b45384..a103c01 100644
> --- a/include/linux/irq.h
> +++ b/include/linux/irq.h
> @@ -35,6 +35,16 @@ typedef void (*irq_flow_handler_t)(unsigned int irq,
> struct irq_desc *desc);
> typedef void (*irq_preflow_handler_t)(struct irq_data *data);
>
> +/* This type is the placeholder for a hardware interrupt number. It has to
> + * be big enough to enclose whatever representation is used by a given
> + * platform.
> + */
> +#ifndef _IRQ_HW_NUMBER_T
> +#define _IRQ_HW_NUMBER_T
> +typedef unsigned long irq_hw_number_t;
> +#endif
> +
> +
> /*
> * IRQ line status.
> *
> @@ -113,14 +123,18 @@ enum {
> };
>
> struct msi_desc;
> +struct irq_domain;
>
> /**
> * struct irq_data - per irq and irq chip data passed down to chip functions
> * @irq: interrupt number
> + * @hwirq: hardware interrupt number, local to the interrupt domain
> * @node: node index useful for balancing
> * @state_use_accessors: status information for irq chip functions.
> * Use accessor functions to deal with it
> * @chip: low level interrupt hardware access
> + * @domain: Interrupt translation domain; responsible for mapping
> + * between hwirq number and linux irq number.
> * @handler_data: per-IRQ data for the irq_chip methods
> * @chip_data: platform-specific per-chip private data for the chip
> * methods, to allow shared chip implementations
> @@ -133,9 +147,11 @@ struct msi_desc;
> */
> struct irq_data {
> unsigned int irq;
> + irq_hw_number_t hwirq;
> unsigned int node;
> unsigned int state_use_accessors;
> struct irq_chip *chip;
> + struct irq_domain *domain;
> void *handler_data;
> void *chip_data;
> struct msi_desc *msi_desc;
> @@ -716,6 +732,71 @@ static inline void irq_gc_unlock(struct irq_chip_generic *gc) { }
>
> #endif /* CONFIG_GENERIC_HARDIRQS */
>
> +/*
> + * irq-domain - IRQ translation domains
> + *
> + * Translation infrastructure between hw and linux irq numbers.
> + */
> +struct device_node;
> +
> +/**
> + * struct irq_domain_ops - Methods for irq_domain objects
> + * @to_irq: (optional) given a local hardware irq number, return the linux
> + * irq number. If to_irq is not implemented, then the irq_domain
> + * will use this translation: irq = (domain->irq_base + hwirq)
> + * @dt_translate: Given a device tree node and interrupt specifier, decode
> + * the hardware irq number and linux irq type value.
> + */
> +struct irq_domain_ops {
> + unsigned int (*to_irq)(struct irq_domain *d, irq_hw_number_t hwirq);
> +
> +#ifdef CONFIG_OF
> + int (*dt_translate)(struct irq_domain *d, struct device_node *node,
> + const u32 *intspec, unsigned int intsize,
> + irq_hw_number_t *out_hwirq, unsigned int *out_type);
> +#endif
> +};
> +
> +/**
> + * struct irq_domain - Hardware interrupt number translation object
> + * @list: Element in global irq_domain list.
> + * @irq_base: Start of irq_desc range assigned to the irq_domain. The creator
> + * of the irq_domain is responsible for allocating the array of
> + * irq_desc structures.
> + * @ops: pointer to irq_domain methods
> + * @priv: private data pointer for use by owner. Not touched by irq_domain
> + * core code.
> + * @of_node: (optional) Pointer to device tree nodes associated with the
> + * irq_domain. Used when decoding device tree interrupt specifiers.
> + */
> +struct irq_domain {
> + struct list_head list;
> + unsigned int irq_base;
> + const struct irq_domain_ops *ops;
> + void *priv;
> +
> + struct device_node *of_node;
> +};
> +
> +/**
> + * irq_domain_to_irq() - Translate from a hardware irq to a linux irq number
> + *
> + * Returns the linux irq number associated with a hardware irq. By default,
> + * the mapping is irq == domain->irq_base + hwirq, but this mapping can
> + * be overridden if the irq_domain implements a .to_irq() hook.
> + */
> +static inline unsigned int irq_domain_to_irq(struct irq_domain *d,
> + irq_hw_number_t hwirq)
> +{
> + return d->ops->to_irq ? d->ops->to_irq(d, hwirq) : d->irq_base + hwirq;
> +}
> +
> +extern void irq_domain_add(struct irq_domain *domain);
> +extern void irq_domain_del(struct irq_domain *domain);
> +extern unsigned int irq_domain_map(struct irq_domain *domain,
> + irq_hw_number_t hwirq);
> +extern void irq_domain_unmap(struct irq_domain *domain, irq_hw_number_t hw);
> +
> #endif /* !CONFIG_S390 */
>
> #endif /* _LINUX_IRQ_H */
> diff --git a/include/linux/of_irq.h b/include/linux/of_irq.h
> index e6955f5..67a2a57 100644
> --- a/include/linux/of_irq.h
> +++ b/include/linux/of_irq.h
> @@ -63,6 +63,7 @@ extern int of_irq_map_one(struct device_node *device, int index,
> extern unsigned int irq_create_of_mapping(struct device_node *controller,
> const u32 *intspec,
> unsigned int intsize);
> +extern void irq_dispose_mapping(unsigned int irq);
> extern int of_irq_to_resource(struct device_node *dev, int index,
> struct resource *r);
> extern int of_irq_count(struct device_node *dev);
> @@ -70,6 +71,7 @@ extern int of_irq_to_resource_table(struct device_node *dev,
> struct resource *res, int nr_irqs);
> extern struct device_node *of_irq_find_parent(struct device_node *child);
>
> +
> #endif /* CONFIG_OF_IRQ */
> #endif /* CONFIG_OF */
> #endif /* __OF_IRQ_H */
> diff --git a/kernel/irq/Makefile b/kernel/irq/Makefile
> index 7329005..aa8feed 100644
> --- a/kernel/irq/Makefile
> +++ b/kernel/irq/Makefile
> @@ -1,5 +1,5 @@
>
> -obj-y := irqdesc.o handle.o manage.o spurious.o resend.o chip.o dummychip.o devres.o
> +obj-y := irqdesc.o handle.o manage.o spurious.o resend.o chip.o dummychip.o devres.o irqdomain.o
> obj-$(CONFIG_GENERIC_IRQ_CHIP) += generic-chip.o
> obj-$(CONFIG_GENERIC_IRQ_PROBE) += autoprobe.o
> obj-$(CONFIG_PROC_FS) += proc.o
> diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
> new file mode 100644
> index 0000000..8310d6e
> --- /dev/null
> +++ b/kernel/irq/irqdomain.c
> @@ -0,0 +1,137 @@
> +
> +#include <linux/irq.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +
> +static LIST_HEAD(irq_domain_list);
> +static DEFINE_MUTEX(irq_domain_mutex);
> +
> +/**
> + * irq_domain_add() - Register an irq_domain
> + * @domain: ptr to initialized irq_domain structure
> + *
> + * Registers an irq_domain structure. The irq_domain must at a minimum be
> + * initialized with an ops structure pointer, and either a ->to_irq hook or
> + * a valid irq_base value. Everything else is optional.
> + */
> +void irq_domain_add(struct irq_domain *domain)
> +{
> + mutex_lock(&irq_domain_mutex);
> + list_add(&domain->list, &irq_domain_list);
> + mutex_unlock(&irq_domain_mutex);
> +}
> +
> +/**
> + * irq_domain_del() - Unregister an irq_domain
> + * @domain: ptr to registered irq_domain.
> + */
> +void irq_domain_del(struct irq_domain *domain)
> +{
> + mutex_lock(&irq_domain_mutex);
> + list_del(&domain->list);
> + mutex_unlock(&irq_domain_mutex);
> +}
> +
> +/**
> + * irq_domain_map() - Allocate and/or increment a reference to a hwirq
> + *
> + * TODO: Establish a linux irq number mapping for a hardware irq. If the
> + * mapping already exists, then increment the reference count and return the
> + * linux irq number.
> + *
> + * At the moment this function is an empty stub since irq_domain initially
> + * only supports the common case of mapping hw irq numbers into a contiguous
> + * range of pre-allocated linux irq_descs based at irq_domain->irq_base. When
> + * irq_domains are extended either to support non-contiguous mappings (ie. to
> + * support MSI interrupts) or to remove preallocation of all irq_descs (as
> + * powerpc does so that irq_descs are only allocated for in-use irq inputs),
> + * then this function will be extended to implement the irq_desc allocation
> + * and reference counting.
> + *
> + * Any caller to this function must arrange to also call irq_domain_unmap()
> + * if the irq ever becomes unused again.
> + */
> +unsigned int irq_domain_map(struct irq_domain *domain, irq_hw_number_t hwirq)
> +{
> + int irq = irq_domain_to_irq(domain, hwirq);
> + struct irq_data *d = irq_get_irq_data(irq);
> +
> + d->domain = domain;
> + d->hwirq = hwirq;
> +
> + return irq;
> +}
> +
> +/**
> + * irq_domain_unmap() - Release a reference to a hwirq
> + *
> + * TODO: decrement the reference count on a hardware irq number. If the ref
> + * count reaches zero, then the irq_desc can be freed.
> + *
> + * At the moment this function is an empty stub. See the comment on
> + * irq_domain_map() for details.
> + */
> +void irq_domain_unmap(struct irq_domain *domain, irq_hw_number_t hwirq)
> +{
> + int irq = irq_domain_to_irq(domain, hwirq);
> + struct irq_data *d = irq_get_irq_data(irq);
> +
> + d->domain = NULL;
> +}
> +
> +#if defined(CONFIG_OF_IRQ) && !defined(CONFIG_PPC)
> +/**
> + * irq_create_of_mapping() - Map a linux irq number from a DT interrupt spec
> + *
> + * Used by the device tree interrupt mapping code to translate a device tree
> + * interrupt specifier to a valid linux irq number. Returns either a valid
> + * linux IRQ number or 0.
> + *
> + * When the caller no longer need the irq number returned by this function it
> + * should arrange to call irq_dispose_mapping().
> + */
> +unsigned int irq_create_of_mapping(struct device_node *controller,
> + const u32 *intspec, unsigned int intsize)
> +{
> + struct irq_domain *domain;
> + irq_hw_number_t hwirq;
> + unsigned int irq, type;
> + int rc = -ENODEV;
> +
> + /* Find a domain which can translate the irq spec */
> + mutex_lock(&irq_domain_mutex);
> + list_for_each_entry(domain, &irq_domain_list, list) {
> + if (!domain->ops->dt_translate)
> + continue;
> + rc = domain->ops->dt_translate(domain, controller,
> + intspec, intsize, &hwirq, &type);
> + if (rc == 0)
> + break;
> + }
> + mutex_unlock(&irq_domain_mutex);
> +
> + if (rc != 0)
> + return 0;
> +
> + irq = irq_domain_map(domain, hwirq);
> + if (type != IRQ_TYPE_NONE)
> + irq_set_irq_type(irq, type);
> + return irq;
> +}
> +EXPORT_SYMBOL_GPL(irq_create_of_mapping);
> +
> +/**
> + * irq_dispose_mapping() - Discard a mapping created by irq_create_of_mapping()
> + * @irq: linux irq number to be discarded
> + *
> + * Calling this function indicates the caller no longer needs a reference to
> + * the linux irq number returned by a prior call to irq_create_of_mapping().
> + */
> +void irq_dispose_mapping(unsigned int irq)
> +{
> + struct irq_data *d = irq_get_irq_data(irq);
> + irq_domain_unmap(d->domain, d->hwirq);
> +}
> +EXPORT_SYMBOL_GPL(irq_dispose_mapping);
> +
> +#endif
>
>
> _______________________________________________
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> linux-arm-kernel@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
--
Jazz is not dead. It just smells funny...
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