Re: [RFC 13/14] irq_domain: Remove 'new' irq_domain in favour of the ppc one

[Rob Herring <robherring2@gmail.com>]

Grant,

On 01/11/2012 02:22 PM, Grant Likely wrote:
> This patch removes the simplistic implementation of irq_domains and enables
> the powerpc infrastructure for all irq_domain users.  The powerpc
> infrastructure includes support for complex mappings between Linux and
> hardware irq numbers, and can manage allocation of irq_descs.
> 
> This patch also converts the few users of irq_domain_add()/irq_domain_del()
> to call irq_domain_add_legacy() instead.

So what is the non-legacy way? Legacy implies we don't want to do it
that way. I guess until we remove all non-DT platforms with GIC we are
stuck with legacy. That seems like it could be a ways out until we get
there.

Rob

> 
> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
> ---
>  arch/arm/common/gic.c               |   83 +++++++-----------
>  arch/arm/common/vic.c               |   16 +---
>  arch/arm/include/asm/hardware/gic.h |    4 +-
>  arch/arm/include/asm/hardware/vic.h |    2 +
>  arch/arm/mach-exynos/common.c       |    2 +-
>  arch/arm/mach-versatile/core.c      |    5 +-
>  drivers/mfd/twl-core.c              |   12 +--
>  include/linux/irqdomain.h           |   42 +---------
>  kernel/irq/irqdomain.c              |  161 +++--------------------------------
>  9 files changed, 64 insertions(+), 263 deletions(-)
> 
> diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
> index 156bc03..d839168 100644
> --- a/arch/arm/common/gic.c
> +++ b/arch/arm/common/gic.c
> @@ -50,7 +50,6 @@ union gic_base {
>  };
>  
>  struct gic_chip_data {
> -	unsigned int irq_offset;
>  	union gic_base dist_base;
>  	union gic_base cpu_base;
>  #ifdef CONFIG_CPU_PM
> @@ -60,9 +59,7 @@ struct gic_chip_data {
>  	u32 __percpu *saved_ppi_enable;
>  	u32 __percpu *saved_ppi_conf;
>  #endif
> -#ifdef CONFIG_IRQ_DOMAIN
> -	struct irq_domain domain;
> -#endif
> +	struct irq_domain *domain;
>  	unsigned int gic_irqs;
>  #ifdef CONFIG_GIC_NON_BANKED
>  	void __iomem *(*get_base)(union gic_base *);
> @@ -281,7 +278,7 @@ asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs)
>  		irqnr = irqstat & ~0x1c00;
>  
>  		if (likely(irqnr > 15 && irqnr < 1021)) {
> -			irqnr = irq_domain_to_irq(&gic->domain, irqnr);
> +			irqnr = irq_find_mapping(gic->domain, irqnr);
>  			handle_IRQ(irqnr, regs);
>  			continue;
>  		}
> @@ -313,8 +310,8 @@ static void gic_handle_cascade_irq(unsigned int irq, struct irq_desc *desc)
>  	if (gic_irq == 1023)
>  		goto out;
>  
> -	cascade_irq = irq_domain_to_irq(&chip_data->domain, gic_irq);
> -	if (unlikely(gic_irq < 32 || gic_irq > 1020 || cascade_irq >= NR_IRQS))
> +	cascade_irq = irq_find_mapping(chip_data->domain, gic_irq);
> +	if (unlikely(gic_irq < 32 || gic_irq > 1020))
>  		do_bad_IRQ(cascade_irq, desc);
>  	else
>  		generic_handle_irq(cascade_irq);
> @@ -347,10 +344,9 @@ void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq)
>  
>  static void __init gic_dist_init(struct gic_chip_data *gic)
>  {
> -	unsigned int i, irq;
> +	unsigned int i;
>  	u32 cpumask;
>  	unsigned int gic_irqs = gic->gic_irqs;
> -	struct irq_domain *domain = &gic->domain;
>  	void __iomem *base = gic_data_dist_base(gic);
>  	u32 cpu = 0;
>  
> @@ -389,23 +385,6 @@ static void __init gic_dist_init(struct gic_chip_data *gic)
>  	for (i = 32; i < gic_irqs; i += 32)
>  		writel_relaxed(0xffffffff, base + GIC_DIST_ENABLE_CLEAR + i * 4 / 32);
>  
> -	/*
> -	 * Setup the Linux IRQ subsystem.
> -	 */
> -	irq_domain_for_each_irq(domain, i, irq) {
> -		if (i < 32) {
> -			irq_set_percpu_devid(irq);
> -			irq_set_chip_and_handler(irq, &gic_chip,
> -						 handle_percpu_devid_irq);
> -			set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
> -		} else {
> -			irq_set_chip_and_handler(irq, &gic_chip,
> -						 handle_fasteoi_irq);
> -			set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
> -		}
> -		irq_set_chip_data(irq, gic);
> -	}
> -
>  	writel_relaxed(1, base + GIC_DIST_CTRL);
>  }
>  
> @@ -621,7 +600,23 @@ static void __init gic_pm_init(struct gic_chip_data *gic)
>  }
>  #endif
>  
> -#ifdef CONFIG_OF
> +static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
> +				irq_hw_number_t hw)
> +{
> +	if (hw < 32) {
> +		irq_set_percpu_devid(irq);
> +		irq_set_chip_and_handler(irq, &gic_chip,
> +					 handle_percpu_devid_irq);
> +		set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
> +	} else {
> +		irq_set_chip_and_handler(irq, &gic_chip,
> +					 handle_fasteoi_irq);
> +		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
> +	}
> +	irq_set_chip_data(irq, d->host_data);
> +	return 0;
> +}
> +
>  static int gic_irq_domain_xlate(struct irq_domain *d,
>  				struct device_node *controller,
>  				const u32 *intspec, unsigned int intsize,
> @@ -642,26 +637,23 @@ static int gic_irq_domain_xlate(struct irq_domain *d,
>  	*out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
>  	return 0;
>  }
> -#endif
>  
>  struct irq_domain_ops gic_irq_domain_ops = {
> -#ifdef CONFIG_OF
> +	.map = gic_irq_domain_map,
>  	.xlate = gic_irq_domain_xlate,
> -#endif
>  };
>  
>  void __init gic_init_bases(unsigned int gic_nr, int irq_start,
>  			   void __iomem *dist_base, void __iomem *cpu_base,
> -			   u32 percpu_offset)
> +			   u32 percpu_offset, struct device_node *node)
>  {
> +	irq_hw_number_t hwirq_base;
>  	struct gic_chip_data *gic;
> -	struct irq_domain *domain;
>  	int gic_irqs;
>  
>  	BUG_ON(gic_nr >= MAX_GIC_NR);
>  
>  	gic = &gic_data[gic_nr];
> -	domain = &gic->domain;
>  #ifdef CONFIG_GIC_NON_BANKED
>  	if (percpu_offset) { /* Frankein-GIC without banked registers... */
>  		unsigned int cpu;
> @@ -697,10 +689,10 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start,
>  	 * For primary GICs, skip over SGIs.
>  	 * For secondary GICs, skip over PPIs, too.
>  	 */
> -	domain->hwirq_base = 32;
> +	hwirq_base = 32;
>  	if (gic_nr == 0) {
>  		if ((irq_start & 31) > 0) {
> -			domain->hwirq_base = 16;
> +			hwirq_base = 16;
>  			if (irq_start != -1)
>  				irq_start = (irq_start & ~31) + 16;
>  		}
> @@ -716,17 +708,11 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start,
>  		gic_irqs = 1020;
>  	gic->gic_irqs = gic_irqs;
>  
> -	domain->nr_irq = gic_irqs - domain->hwirq_base;
> -	domain->irq_base = irq_alloc_descs(irq_start, 16, domain->nr_irq,
> -					   numa_node_id());
> -	if (IS_ERR_VALUE(domain->irq_base)) {
> -		WARN(1, "Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
> -		     irq_start);
> -		domain->irq_base = irq_start;
> -	}
> -	domain->host_data = gic;
> -	domain->ops = &gic_irq_domain_ops;
> -	irq_domain_add(domain);
> +	gic->domain = irq_domain_add_legacy(node, gic_irqs, irq_start,
> +					    hwirq_base, &gic_irq_domain_ops);
> +	if (WARN_ON(!gic->domain))
> +		return;
> +	gic->domain->host_data = gic;
>  
>  	gic_chip.flags |= gic_arch_extn.flags;
>  	gic_dist_init(gic);
> @@ -771,7 +757,6 @@ int __init gic_of_init(struct device_node *node, struct device_node *parent)
>  	void __iomem *dist_base;
>  	u32 percpu_offset;
>  	int irq;
> -	struct irq_domain *domain = &gic_data[gic_cnt].domain;
>  
>  	if (WARN_ON(!node))
>  		return -ENODEV;
> @@ -785,9 +770,7 @@ int __init gic_of_init(struct device_node *node, struct device_node *parent)
>  	if (of_property_read_u32(node, "cpu-offset", &percpu_offset))
>  		percpu_offset = 0;
>  
> -	domain->of_node = of_node_get(node);
> -
> -	gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset);
> +	gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset, node);
>  
>  	if (parent) {
>  		irq = irq_of_parse_and_map(node, 0);
> diff --git a/arch/arm/common/vic.c b/arch/arm/common/vic.c
> index dcb004a..b9b1827 100644
> --- a/arch/arm/common/vic.c
> +++ b/arch/arm/common/vic.c
> @@ -56,7 +56,7 @@ struct vic_device {
>  	u32		int_enable;
>  	u32		soft_int;
>  	u32		protect;
> -	struct irq_domain domain;
> +	struct irq_domain *domain;
>  };
>  
>  /* we cannot allocate memory when VICs are initially registered */
> @@ -192,14 +192,8 @@ static void __init vic_register(void __iomem *base, unsigned int irq,
>  	v->resume_sources = resume_sources;
>  	v->irq = irq;
>  	vic_id++;
> -
> -	v->domain.irq_base = irq;
> -	v->domain.nr_irq = 32;
> -#ifdef CONFIG_OF_IRQ
> -	v->domain.of_node = of_node_get(node);
> -#endif /* CONFIG_OF */
> -	v->domain.ops = &irq_domain_simple_ops;
> -	irq_domain_add(&v->domain);
> +	v->domain = irq_domain_add_legacy(node, 32, irq, 0,
> +					  &irq_domain_simple_ops);
>  }
>  
>  static void vic_ack_irq(struct irq_data *d)
> @@ -348,7 +342,7 @@ static void __init vic_init_st(void __iomem *base, unsigned int irq_start,
>  	vic_register(base, irq_start, 0, node);
>  }
>  
> -static void __init __vic_init(void __iomem *base, unsigned int irq_start,
> +void __init __vic_init(void __iomem *base, unsigned int irq_start,
>  			      u32 vic_sources, u32 resume_sources,
>  			      struct device_node *node)
>  {
> @@ -444,7 +438,7 @@ static int handle_one_vic(struct vic_device *vic, struct pt_regs *regs)
>  	stat = readl_relaxed(vic->base + VIC_IRQ_STATUS);
>  	while (stat) {
>  		irq = ffs(stat) - 1;
> -		handle_IRQ(irq_domain_to_irq(&vic->domain, irq), regs);
> +		handle_IRQ(irq_find_mapping(vic->domain, irq), regs);
>  		stat &= ~(1 << irq);
>  		handled = 1;
>  	}
> diff --git a/arch/arm/include/asm/hardware/gic.h b/arch/arm/include/asm/hardware/gic.h
> index 4bdfe00..4b1ce6c 100644
> --- a/arch/arm/include/asm/hardware/gic.h
> +++ b/arch/arm/include/asm/hardware/gic.h
> @@ -39,7 +39,7 @@ struct device_node;
>  extern struct irq_chip gic_arch_extn;
>  
>  void gic_init_bases(unsigned int, int, void __iomem *, void __iomem *,
> -		    u32 offset);
> +		    u32 offset, struct device_node *);
>  int gic_of_init(struct device_node *node, struct device_node *parent);
>  void gic_secondary_init(unsigned int);
>  void gic_handle_irq(struct pt_regs *regs);
> @@ -49,7 +49,7 @@ void gic_raise_softirq(const struct cpumask *mask, unsigned int irq);
>  static inline void gic_init(unsigned int nr, int start,
>  			    void __iomem *dist , void __iomem *cpu)
>  {
> -	gic_init_bases(nr, start, dist, cpu, 0);
> +	gic_init_bases(nr, start, dist, cpu, 0, NULL);
>  }
>  
>  #endif
> diff --git a/arch/arm/include/asm/hardware/vic.h b/arch/arm/include/asm/hardware/vic.h
> index f42ebd6..e14af1a 100644
> --- a/arch/arm/include/asm/hardware/vic.h
> +++ b/arch/arm/include/asm/hardware/vic.h
> @@ -47,6 +47,8 @@
>  struct device_node;
>  struct pt_regs;
>  
> +void __vic_init(void __iomem *base, unsigned int irq_start, u32 vic_sources,
> +		u32 resume_sources, struct device_node *node);
>  void vic_init(void __iomem *base, unsigned int irq_start, u32 vic_sources, u32 resume_sources);
>  int vic_of_init(struct device_node *node, struct device_node *parent);
>  void vic_handle_irq(struct pt_regs *regs);
> diff --git a/arch/arm/mach-exynos/common.c b/arch/arm/mach-exynos/common.c
> index 0f22997..b0cf428 100644
> --- a/arch/arm/mach-exynos/common.c
> +++ b/arch/arm/mach-exynos/common.c
> @@ -399,7 +399,7 @@ void __init exynos4_init_irq(void)
>  	gic_bank_offset = soc_is_exynos4412() ? 0x4000 : 0x8000;
>  
>  	if (!of_have_populated_dt())
> -		gic_init_bases(0, IRQ_PPI(0), S5P_VA_GIC_DIST, S5P_VA_GIC_CPU, gic_bank_offset);
> +		gic_init_bases(0, IRQ_PPI(0), S5P_VA_GIC_DIST, S5P_VA_GIC_CPU, gic_bank_offset, NULL);
>  #ifdef CONFIG_OF
>  	else
>  		of_irq_init(exynos4_dt_irq_match);
> diff --git a/arch/arm/mach-versatile/core.c b/arch/arm/mach-versatile/core.c
> index 02b7b93..e924f15 100644
> --- a/arch/arm/mach-versatile/core.c
> +++ b/arch/arm/mach-versatile/core.c
> @@ -98,8 +98,9 @@ static const struct of_device_id sic_of_match[] __initconst = {
>  
>  void __init versatile_init_irq(void)
>  {
> -	vic_init(VA_VIC_BASE, IRQ_VIC_START, ~0, 0);
> -	irq_domain_generate_simple(vic_of_match, VERSATILE_VIC_BASE, IRQ_VIC_START);
> +	__vic_init(VA_VIC_BASE, IRQ_VIC_START, ~0, 0,
> +			of_find_matching_node_by_address(NULL, vic_of_match,
> +							 VERSATILE_VIC_BASE));
>  
>  	writel(~0, VA_SIC_BASE + SIC_IRQ_ENABLE_CLEAR);
>  
> diff --git a/drivers/mfd/twl-core.c b/drivers/mfd/twl-core.c
> index e04e04dd..aab236f 100644
> --- a/drivers/mfd/twl-core.c
> +++ b/drivers/mfd/twl-core.c
> @@ -263,8 +263,6 @@ struct twl_client {
>  
>  static struct twl_client twl_modules[TWL_NUM_SLAVES];
>  
> -static struct irq_domain domain;
> -
>  /* mapping the module id to slave id and base address */
>  struct twl_mapping {
>  	unsigned char sid;	/* Slave ID */
> @@ -1225,14 +1223,8 @@ twl_probe(struct i2c_client *client, const struct i2c_device_id *id)
>  
>  	pdata->irq_base = status;
>  	pdata->irq_end = pdata->irq_base + nr_irqs;
> -
> -	domain.irq_base = pdata->irq_base;
> -	domain.nr_irq = nr_irqs;
> -#ifdef CONFIG_OF_IRQ
> -	domain.of_node = of_node_get(node);
> -	domain.ops = &irq_domain_simple_ops;
> -#endif
> -	irq_domain_add(&domain);
> +	irq_domain_add_legacy(node, nr_irqs, pdata->irq_base, 0,
> +			      &irq_domain_simple_ops);
>  
>  	if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C) == 0) {
>  		dev_dbg(&client->dev, "can't talk I2C?\n");
> diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
> index 6fb3531..7c25e7c 100644
> --- a/include/linux/irqdomain.h
> +++ b/include/linux/irqdomain.h
> @@ -116,20 +116,15 @@ struct irq_domain {
>  	void *host_data;
>  	irq_hw_number_t inval_irq;
>  
> -	unsigned int irq_base;
> -	unsigned int nr_irq;
> -	unsigned int hwirq_base;
> -
>  	/* Optional device node pointer */
>  	struct device_node *of_node;
>  };
>  
>  #ifdef CONFIG_IRQ_DOMAIN
> -#ifdef CONFIG_PPC
>  struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
>  					 unsigned int size,
>  					 unsigned int first_irq,
> -					 unsigned int first_hwirq,
> +					 irq_hw_number_t first_hwirq,
>  					 struct irq_domain_ops *ops);
>  struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
>  					 unsigned int size,
> @@ -146,9 +141,8 @@ static inline struct irq_domain *irq_domain_add_legacy_isa(
>  				struct device_node *of_node,
>  				struct irq_domain_ops *ops)
>  {
> -	return irq_domain_add_legacy(of_node, NUM_ISA_INTERRUPTS-1, 1, 1, ops);
> +	return irq_domain_add_legacy(of_node, NUM_ISA_INTERRUPTS, 0, 0, ops);
>  }
> -
>  extern struct irq_domain *irq_find_host(struct device_node *node);
>  extern void irq_set_default_host(struct irq_domain *host);
>  extern void irq_set_virq_count(unsigned int count);
> @@ -167,38 +161,7 @@ extern unsigned int irq_radix_revmap_lookup(struct irq_domain *host,
>  extern unsigned int irq_linear_revmap(struct irq_domain *host,
>  				      irq_hw_number_t hwirq);
>  
> -#else /* CONFIG_PPC */
> -
> -/**
> - * 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,
> -					     unsigned long hwirq)
> -{
> -	if (d->ops->to_irq)
> -		return d->ops->to_irq(d, hwirq);
> -	if (WARN_ON(hwirq < d->hwirq_base))
> -		return 0;
> -	return d->irq_base + hwirq - d->hwirq_base;
> -}
> -
> -#define irq_domain_for_each_hwirq(d, hw) \
> -	for (hw = d->hwirq_base; hw < d->hwirq_base + d->nr_irq; hw++)
> -
> -#define irq_domain_for_each_irq(d, hw, irq) \
> -	for (hw = d->hwirq_base, irq = irq_domain_to_irq(d, hw); \
> -	     hw < d->hwirq_base + d->nr_irq; \
> -	     hw++, irq = irq_domain_to_irq(d, hw))
> -
> -extern void irq_domain_add(struct irq_domain *domain);
> -extern void irq_domain_del(struct irq_domain *domain);
> -
>  extern struct irq_domain_ops irq_domain_simple_ops;
> -
>  #if defined(CONFIG_OF_IRQ)
>  extern void irq_domain_add_simple(struct device_node *controller, int irq_base);
>  extern void irq_domain_generate_simple(const struct of_device_id *match,
> @@ -207,7 +170,6 @@ extern void irq_domain_generate_simple(const struct of_device_id *match,
>  static inline void irq_domain_generate_simple(const struct of_device_id *match,
>  					u64 phys_base, unsigned int irq_start) { }
>  #endif /* !CONFIG_OF_IRQ */
> -#endif /* !CONFIG_PPC */
>  #endif /* CONFIG_IRQ_DOMAIN */
>  
>  #endif /* _LINUX_IRQDOMAIN_H */
> diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
> index d4759d0..b90a32e 100644
> --- a/kernel/irq/irqdomain.c
> +++ b/kernel/irq/irqdomain.c
> @@ -11,7 +11,6 @@
>  static LIST_HEAD(irq_domain_list);
>  static DEFINE_MUTEX(irq_domain_mutex);
>  
> -#ifdef CONFIG_PPC
>  static DEFINE_MUTEX(revmap_trees_mutex);
>  static unsigned int irq_virq_count = NR_IRQS;
>  static struct irq_domain *irq_default_domain;
> @@ -79,7 +78,7 @@ static struct irq_domain *irq_domain_add(struct device_node *of_node,
>  struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
>  					 unsigned int size,
>  					 unsigned int first_irq,
> -					 unsigned int first_hwirq,
> +					 irq_hw_number_t first_hwirq,
>  					 struct irq_domain_ops *ops)
>  {
>  	struct irq_domain *domain;
> @@ -661,124 +660,11 @@ static int __init irq_debugfs_init(void)
>  __initcall(irq_debugfs_init);
>  #endif /* CONFIG_VIRQ_DEBUG */
>  
> -#else /* CONFIG_PPC */
> -
> -/**
> - * 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)
> -{
> -	struct irq_data *d;
> -	int hwirq, irq;
> -
> -	/*
> -	 * This assumes that the irq_domain owner has already allocated
> -	 * the irq_descs.  This block will be removed when support for dynamic
> -	 * allocation of irq_descs is added to irq_domain.
> -	 */
> -	irq_domain_for_each_irq(domain, hwirq, irq) {
> -		d = irq_get_irq_data(irq);
> -		if (!d) {
> -			WARN(1, "error: assigning domain to non existant irq_desc");
> -			return;
> -		}
> -		if (d->domain) {
> -			/* things are broken; just report, don't clean up */
> -			WARN(1, "error: irq_desc already assigned to a domain");
> -			return;
> -		}
> -		d->domain = domain;
> -		d->hwirq = hwirq;
> -	}
> -
> -	mutex_lock(&irq_domain_mutex);
> -	list_add(&domain->link, &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)
> -{
> -	struct irq_data *d;
> -	int hwirq, irq;
> -
> -	mutex_lock(&irq_domain_mutex);
> -	list_del(&domain->link);
> -	mutex_unlock(&irq_domain_mutex);
> -
> -	/* Clear the irq_domain assignments */
> -	irq_domain_for_each_irq(domain, hwirq, irq) {
> -		d = irq_get_irq_data(irq);
> -		d->domain = NULL;
> -	}
> -}
> -
> -#if defined(CONFIG_OF_IRQ)
> -/**
> - * 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)
> +int irq_domain_simple_map(struct irq_domain *d, unsigned int irq,
> +			  irq_hw_number_t hwirq)
>  {
> -	struct irq_domain *domain;
> -	unsigned long hwirq;
> -	unsigned int irq, type;
> -	int rc = -EINVAL;
> -
> -	/* Find a domain which can translate the irq spec */
> -	mutex_lock(&irq_domain_mutex);
> -	list_for_each_entry(domain, &irq_domain_list, link) {
> -		if (!domain->ops->xlate)
> -			continue;
> -		rc = domain->ops->xlate(domain, controller,
> -					intspec, intsize, &hwirq, &type);
> -		if (rc == 0)
> -			break;
> -	}
> -	mutex_unlock(&irq_domain_mutex);
> -
> -	if (rc != 0)
> -		return 0;
> -
> -	irq = irq_domain_to_irq(domain, hwirq);
> -	if (type != IRQ_TYPE_NONE)
> -		irq_set_irq_type(irq, type);
> -	pr_debug("%s: mapped hwirq=%i to irq=%i, flags=%x\n",
> -		 controller->full_name, (int)hwirq, 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)
> -{
> -	/*
> -	 * nothing yet; will be filled when support for dynamic allocation of
> -	 * irq_descs is added to irq_domain
> -	 */
> +	return 0;
>  }
> -EXPORT_SYMBOL_GPL(irq_dispose_mapping);
>  
>  int irq_domain_simple_xlate(struct irq_domain *d,
>  			    struct device_node *controller,
> @@ -789,10 +675,6 @@ int irq_domain_simple_xlate(struct irq_domain *d,
>  		return -EINVAL;
>  	if (intsize < 1)
>  		return -EINVAL;
> -	if (d->nr_irq && ((intspec[0] < d->hwirq_base) ||
> -	    (intspec[0] >= d->hwirq_base + d->nr_irq)))
> -		return -EINVAL;
> -
>  	*out_hwirq = intspec[0];
>  	*out_type = IRQ_TYPE_NONE;
>  	if (intsize > 1)
> @@ -800,23 +682,17 @@ int irq_domain_simple_xlate(struct irq_domain *d,
>  	return 0;
>  }
>  
> -/**
> - * irq_domain_create_simple() - Set up a 'simple' translation range
> - */
> +struct irq_domain_ops irq_domain_simple_ops = {
> +	.map = irq_domain_simple_map,
> +	.xlate = irq_domain_simple_xlate,
> +};
> +EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
> +
> +#ifdef CONFIG_OF_IRQ
>  void irq_domain_add_simple(struct device_node *controller, int irq_base)
>  {
> -	struct irq_domain *domain;
> -
> -	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
> -	if (!domain) {
> -		WARN_ON(1);
> -		return;
> -	}
> -
> -	domain->irq_base = irq_base;
> -	domain->of_node = of_node_get(controller);
> -	domain->ops = &irq_domain_simple_ops;
> -	irq_domain_add(domain);
> +	irq_domain_add_legacy(controller, 32, irq_base, 0,
> +			      &irq_domain_simple_ops);
>  }
>  EXPORT_SYMBOL_GPL(irq_domain_add_simple);
>  
> @@ -831,13 +707,4 @@ void irq_domain_generate_simple(const struct of_device_id *match,
>  		irq_domain_add_simple(node, irq_start);
>  }
>  EXPORT_SYMBOL_GPL(irq_domain_generate_simple);
> -#endif /* CONFIG_OF_IRQ */
> -
> -struct irq_domain_ops irq_domain_simple_ops = {
> -#ifdef CONFIG_OF_IRQ
> -	.xlate = irq_domain_simple_xlate,
> -#endif /* CONFIG_OF_IRQ */
> -};
> -EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
> -
> -#endif /* !CONFIG_PPC */
> +#endif