Patchwork irq: move some interrupt arch_* functions into struct irq_chip.

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Submitter Ian Campbell
Date March 12, 2010, 9:45 a.m.
Message ID <1268387116-30522-1-git-send-email-ian.campbell@citrix.com>
Download mbox | patch
Permalink /patch/47669/
State Not Applicable
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Ian Campbell - March 12, 2010, 9:45 a.m.
Move arch_init_copy_chip_data and arch_free_chip_data into function
pointers in struct irq_chip since they operate on irq_desc->chip_data.

arch_init_chip_data cannot be moved into struct irq_chip at this time
because irq_desc->chip is not known at the time the irq_desc is
setup. For now rename arch_init_chip_data to arch_init_irq_desc (for
PowerPC, the only other user, whose usage better matches the new name)
and on x86 convert arch_init_chip_data to x86_init_chip_data and
call this whenever a new struct irq_desc is allocated.

I've retained the chip_data behaviour for uv_irq although it isn't
clear to me if these interrupt types support migration or how closely
related to the APIC modes they really are. If it weren't for this the
x86_{init,copy,free}_chip_data functions could be static to
io_apic.c.

I've tested by booting on a 64 bit system, but it's not clear to me
what actions I need to take to actually exercise some of these code
paths.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Michael Ellerman <michael@ellerman.id.au> [PowerPC rename portion]
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: x86@kernel.org
Cc: linuxppc-dev@ozlabs.org
Cc: linux-kernel@vger.kernel.org
---
 arch/powerpc/kernel/irq.c      |    2 +-
 arch/x86/include/asm/hw_irq.h  |   11 +++++++-
 arch/x86/kernel/apic/io_apic.c |   58 +++++++++++++++++++++++++++++++++++++---
 arch/x86/kernel/uv_irq.c       |    5 +++
 include/linux/interrupt.h      |    2 +-
 include/linux/irq.h            |   12 +++++---
 kernel/irq/handle.c            |    2 +-
 kernel/irq/numa_migrate.c      |   12 +++++++-
 kernel/softirq.c               |    3 +-
 9 files changed, 91 insertions(+), 16 deletions(-)
Yinghai Lu - March 12, 2010, 7:26 p.m.
On 03/12/2010 01:45 AM, Ian Campbell wrote:
> Move arch_init_copy_chip_data and arch_free_chip_data into function
> pointers in struct irq_chip since they operate on irq_desc->chip_data.
> 
> arch_init_chip_data cannot be moved into struct irq_chip at this time
> because irq_desc->chip is not known at the time the irq_desc is
> setup. For now rename arch_init_chip_data to arch_init_irq_desc (for
> PowerPC, the only other user, whose usage better matches the new name)
> and on x86 convert arch_init_chip_data to x86_init_chip_data and
> call this whenever a new struct irq_desc is allocated.
> 
> I've retained the chip_data behaviour for uv_irq although it isn't
> clear to me if these interrupt types support migration or how closely
> related to the APIC modes they really are. If it weren't for this the
> x86_{init,copy,free}_chip_data functions could be static to
> io_apic.c.
> 
> I've tested by booting on a 64 bit system, but it's not clear to me
> what actions I need to take to actually exercise some of these code
> paths.
> 
> Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> Acked-by: Michael Ellerman <michael@ellerman.id.au> [PowerPC rename portion]
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: H. Peter Anvin <hpa@zytor.com>
> Cc: Eric W. Biederman <ebiederm@xmission.com>
> Cc: Yinghai Lu <yinghai@kernel.org>
> Cc: Jeremy Fitzhardinge <jeremy@goop.org>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: x86@kernel.org
> Cc: linuxppc-dev@ozlabs.org
> Cc: linux-kernel@vger.kernel.org
> ---
>  arch/powerpc/kernel/irq.c      |    2 +-
>  arch/x86/include/asm/hw_irq.h  |   11 +++++++-
>  arch/x86/kernel/apic/io_apic.c |   58 +++++++++++++++++++++++++++++++++++++---
>  arch/x86/kernel/uv_irq.c       |    5 +++
>  include/linux/interrupt.h      |    2 +-
>  include/linux/irq.h            |   12 +++++---
>  kernel/irq/handle.c            |    2 +-
>  kernel/irq/numa_migrate.c      |   12 +++++++-
>  kernel/softirq.c               |    3 +-
>  9 files changed, 91 insertions(+), 16 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
> index 64f6f20..002d87f 100644
> --- a/arch/powerpc/kernel/irq.c
> +++ b/arch/powerpc/kernel/irq.c
> @@ -1088,7 +1088,7 @@ int arch_early_irq_init(void)
>  	return 0;
>  }
>  
> -int arch_init_chip_data(struct irq_desc *desc, int node)
> +int arch_init_irq_desc(struct irq_desc *desc, int node)
>  {
>  	desc->status |= IRQ_NOREQUEST;
>  	return 0;
> diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
> index a929c9e..1bc7063 100644
> --- a/arch/x86/include/asm/hw_irq.h
> +++ b/arch/x86/include/asm/hw_irq.h
> @@ -20,9 +20,9 @@
>  #include <linux/percpu.h>
>  #include <linux/profile.h>
>  #include <linux/smp.h>
> +#include <linux/irq.h>
>  
>  #include <asm/atomic.h>
> -#include <asm/irq.h>
>  #include <asm/sections.h>
>  
>  /* Interrupt handlers registered during init_IRQ */
> @@ -61,6 +61,15 @@ extern void init_VISWS_APIC_irqs(void);
>  extern void setup_IO_APIC(void);
>  extern void disable_IO_APIC(void);
>  
> +extern int x86_init_chip_data(struct irq_desc *desc, int node);
> +
> +#ifdef CONFIG_SPARSE_IRQ
> +extern void x86_copy_chip_data(struct irq_desc *old_desc,
> +				  struct irq_desc *desc, int node);
> +extern void x86_free_chip_data(struct irq_desc *old_desc,
> +				  struct irq_desc *desc);
> +#endif
> +
>  struct io_apic_irq_attr {
>  	int ioapic;
>  	int ioapic_pin;
> diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
> index e4e0ddc..12e5cf4 100644
> --- a/arch/x86/kernel/apic/io_apic.c
> +++ b/arch/x86/kernel/apic/io_apic.c
> @@ -211,7 +211,7 @@ static struct irq_cfg *get_one_free_irq_cfg(int node)
>  	return cfg;
>  }
>  
> -int arch_init_chip_data(struct irq_desc *desc, int node)
> +int x86_init_chip_data(struct irq_desc *desc, int node)
>  {
>  	struct irq_cfg *cfg;
>  
> @@ -287,8 +287,8 @@ static void free_irq_2_pin(struct irq_cfg *old_cfg, struct irq_cfg *cfg)
>  	old_cfg->irq_2_pin = NULL;
>  }
>  
> -void arch_init_copy_chip_data(struct irq_desc *old_desc,
> -				 struct irq_desc *desc, int node)
> +void x86_copy_chip_data(struct irq_desc *old_desc,
> +			   struct irq_desc *desc, int node)
>  {
>  	struct irq_cfg *cfg;
>  	struct irq_cfg *old_cfg;
> @@ -312,7 +312,7 @@ static void free_irq_cfg(struct irq_cfg *old_cfg)
>  	kfree(old_cfg);
>  }
>  
> -void arch_free_chip_data(struct irq_desc *old_desc, struct irq_desc *desc)
> +void x86_free_chip_data(struct irq_desc *old_desc, struct irq_desc *desc)
>  {
>  	struct irq_cfg *old_cfg, *cfg;
>  
> @@ -336,6 +336,11 @@ struct irq_cfg *irq_cfg(unsigned int irq)
>  	return irq < nr_irqs ? irq_cfgx + irq : NULL;
>  }
>  
> +int x86_init_chip_data(struct irq_desc *desc, int node)
> +{
> +	return 0;
> +}
> +

you could put one dummy x86_copy_chip_data and x86_free_chip_data here too.

>  #endif
>  
>  struct io_apic {
> @@ -1520,6 +1525,7 @@ static void __init setup_IO_APIC_irqs(void)
>  			printk(KERN_INFO "can not get irq_desc for %d\n", irq);
>  			continue;
>  		}
> +		x86_init_chip_data(desc, node);
>  		cfg = desc->chip_data;
>  		add_pin_to_irq_node(cfg, node, apic_id, pin);
>  		/*
> @@ -1570,6 +1576,7 @@ void setup_IO_APIC_irq_extra(u32 gsi)
>  		printk(KERN_INFO "can not get irq_desc for %d\n", irq);
>  		return;
>  	}
> +	x86_init_chip_data(desc, node);
>  
>  	cfg = desc->chip_data;
>  	add_pin_to_irq_node(cfg, node, apic_id, pin);
> @@ -2739,6 +2746,11 @@ static struct irq_chip ioapic_chip __read_mostly = {
>  	.set_affinity	= set_ioapic_affinity_irq,
>  #endif
>  	.retrigger	= ioapic_retrigger_irq,
> +
> +#ifdef CONFIG_SPARSE_IRQ
> +	.copy_chip_data = x86_copy_chip_data,
> +	.free_chip_data = x86_free_chip_data,
> +#endif
>  };
>  
>  static struct irq_chip ir_ioapic_chip __read_mostly = {
> @@ -2754,6 +2766,11 @@ static struct irq_chip ir_ioapic_chip __read_mostly = {
>  #endif
>  #endif
>  	.retrigger	= ioapic_retrigger_irq,
> +
> +#ifdef CONFIG_SPARSE_IRQ
> +	.copy_chip_data = x86_copy_chip_data,
> +	.free_chip_data = x86_free_chip_data,
> +#endif
>  };
>  
>  static inline void init_IO_APIC_traps(void)
> @@ -3261,6 +3278,7 @@ unsigned int create_irq_nr(unsigned int irq_want, int node)
>  			printk(KERN_INFO "can not get irq_desc for %d\n", new);
>  			continue;
>  		}
> +		x86_init_chip_data(desc_new, node);
>  		cfg_new = desc_new->chip_data;
>  
>  		if (cfg_new->vector != 0)
> @@ -3466,6 +3484,11 @@ static struct irq_chip msi_chip = {
>  	.set_affinity	= set_msi_irq_affinity,
>  #endif
>  	.retrigger	= ioapic_retrigger_irq,
> +
> +#ifdef CONFIG_SPARSE_IRQ
> +	.copy_chip_data = x86_copy_chip_data,
> +	.free_chip_data = x86_free_chip_data,
> +#endif
>  };
>  
>  static struct irq_chip msi_ir_chip = {
> @@ -3479,6 +3502,11 @@ static struct irq_chip msi_ir_chip = {
>  #endif
>  #endif
>  	.retrigger	= ioapic_retrigger_irq,
> +
> +#ifdef CONFIG_SPARSE_IRQ
> +	.copy_chip_data = x86_copy_chip_data,
> +	.free_chip_data = x86_free_chip_data,
> +#endif
>  };
>  
>  /*
> @@ -3638,6 +3666,11 @@ static struct irq_chip dmar_msi_type = {
>  	.set_affinity = dmar_msi_set_affinity,
>  #endif
>  	.retrigger = ioapic_retrigger_irq,
> +
> +#ifdef CONFIG_SPARSE_IRQ
> +	.copy_chip_data = x86_copy_chip_data,
> +	.free_chip_data = x86_free_chip_data,
> +#endif
>  };
>  
>  int arch_setup_dmar_msi(unsigned int irq)
> @@ -3695,6 +3728,11 @@ static struct irq_chip ir_hpet_msi_type = {
>  #endif
>  #endif
>  	.retrigger = ioapic_retrigger_irq,
> +
> +#ifdef CONFIG_SPARSE_IRQ
> +	.copy_chip_data = x86_copy_chip_data,
> +	.free_chip_data = x86_free_chip_data,
> +#endif
>  };
>  
>  static struct irq_chip hpet_msi_type = {
> @@ -3706,6 +3744,11 @@ static struct irq_chip hpet_msi_type = {
>  	.set_affinity = hpet_msi_set_affinity,
>  #endif
>  	.retrigger = ioapic_retrigger_irq,
> +
> +#ifdef CONFIG_SPARSE_IRQ
> +	.copy_chip_data = x86_copy_chip_data,
> +	.free_chip_data = x86_free_chip_data,
> +#endif
>  };
>  
>  int arch_setup_hpet_msi(unsigned int irq, unsigned int id)
> @@ -3792,6 +3835,11 @@ static struct irq_chip ht_irq_chip = {
>  	.set_affinity	= set_ht_irq_affinity,
>  #endif
>  	.retrigger	= ioapic_retrigger_irq,
> +
> +#ifdef CONFIG_SPARSE_IRQ
> +	.copy_chip_data = x86_copy_chip_data,
> +	.free_chip_data = x86_free_chip_data,
> +#endif
>  };
>  
>  int arch_setup_ht_irq(unsigned int irq, struct pci_dev *dev)
> @@ -3919,6 +3967,7 @@ static int __io_apic_set_pci_routing(struct device *dev, int irq,
>  		printk(KERN_INFO "can not get irq_desc %d\n", irq);
>  		return 0;
>  	}
> +	x86_init_chip_data(desc, node);
>  
>  	pin = irq_attr->ioapic_pin;
>  	trigger = irq_attr->trigger;
> @@ -4313,6 +4362,7 @@ void __init pre_init_apic_IRQ0(void)
>  	phys_cpu_present_map = physid_mask_of_physid(boot_cpu_physical_apicid);
>  #endif
>  	desc = irq_to_desc_alloc_node(0, 0);
> +	x86_init_chip_data(desc, 0);
>  
>  	setup_local_APIC();
>  
> diff --git a/arch/x86/kernel/uv_irq.c b/arch/x86/kernel/uv_irq.c
> index ece73d8..df2c6d6 100644
> --- a/arch/x86/kernel/uv_irq.c
> +++ b/arch/x86/kernel/uv_irq.c
> @@ -55,6 +55,11 @@ struct irq_chip uv_irq_chip = {
>  	.eoi		= uv_ack_apic,
>  	.end		= uv_noop,
>  	.set_affinity	= uv_set_irq_affinity,
> +
> +#ifdef CONFIG_SPARSE_IRQ
> +	.copy_chip_data = x86_copy_chip_data,
> +	.free_chip_data = x86_free_chip_data,
> +#endif
>  };
>  
>  /*
> diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
> index 75f3f00..cc4cd22 100644
> --- a/include/linux/interrupt.h
> +++ b/include/linux/interrupt.h
> @@ -611,6 +611,6 @@ struct irq_desc;
>  extern int early_irq_init(void);
>  extern int arch_probe_nr_irqs(void);
>  extern int arch_early_irq_init(void);
> -extern int arch_init_chip_data(struct irq_desc *desc, int node);
> +extern int arch_init_irq_desc(struct irq_desc *desc, int node);
>  
>  #endif
> diff --git a/include/linux/irq.h b/include/linux/irq.h
> index 707ab12..558bd2d 100644
> --- a/include/linux/irq.h
> +++ b/include/linux/irq.h
> @@ -131,6 +131,14 @@ struct irq_chip {
>  	void		(*bus_lock)(unsigned int irq);
>  	void		(*bus_sync_unlock)(unsigned int irq);
>  
> +	/* for move_irq_desc */
> +#ifdef CONFIG_SPARSE_IRQ
> +	void 		(*copy_chip_data)(struct irq_desc *old_desc,
> +					  struct irq_desc *desc, int node);
> +	void		(*free_chip_data)(struct irq_desc *old_desc,
> +					  struct irq_desc *desc);
> +#endif
> +
>  	/* Currently used only by UML, might disappear one day.*/
>  #ifdef CONFIG_IRQ_RELEASE_METHOD
>  	void		(*release)(unsigned int irq, void *dev_id);
> @@ -208,10 +216,6 @@ struct irq_desc {
>  	const char		*name;
>  } ____cacheline_internodealigned_in_smp;
>  
> -extern void arch_init_copy_chip_data(struct irq_desc *old_desc,
> -					struct irq_desc *desc, int node);
> -extern void arch_free_chip_data(struct irq_desc *old_desc, struct irq_desc *desc);
> -
>  #ifndef CONFIG_SPARSE_IRQ
>  extern struct irq_desc irq_desc[NR_IRQS];
>  #endif
> diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
> index 76d5a67..168e2f8 100644
> --- a/kernel/irq/handle.c
> +++ b/kernel/irq/handle.c
> @@ -120,7 +120,6 @@ static void init_one_irq_desc(int irq, struct irq_desc *desc, int node)
>  		BUG_ON(1);
>  	}
>  	init_desc_masks(desc);
> -	arch_init_chip_data(desc, node);
>  }
>  
>  /*
> @@ -228,6 +227,7 @@ struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)
>  		BUG_ON(1);
>  	}
>  	init_one_irq_desc(irq, desc, node);
> +	arch_init_irq_desc(desc, node);

you move out init_chip_data for x86 out of irq_to_desc_alloc_node
current init_chip_data in irq_to_desc_alloc_node is protected by sparse_irq_lock.


wonder if you could let arch_init_irq_desc for x86 to call x86_init_chip_data?

or let add another irq_to_desc_alloc_node_f to take extra func call.

like 
typedef int (*init_chip_data_f)(struct irq_desc *desc, int node);
struct irq_desc * __ref irq_to_desc_alloc_node_f(unsigned int irq, int node, init_chip_data_f *f);

struct irq_desc * __ref irq_to_desc_alloc_node_f(unsigned int irq, int node)
{
 irq_to_desc_alloc_node(irq, node, NULL);
}

then for x86

int arch_init_irq_desc(struct irq_desc *desc, int node, init_chip_data_f *f)
{
	if (!f)
		return x86_init_chip_data(desc, node);
 	f(desc, node);
}

after that xen could use
irq_to_desc_alloc_node_f(irq, node, xen_init_chip_data);

as need...

at last we don't need to call x86_init_chip_data everywhere.

Thanks

Yinghai
Eric W. Biederman - March 13, 2010, 12:29 a.m.
Yinghai Lu <yinghai@kernel.org> writes:

> On 03/12/2010 01:45 AM, Ian Campbell wrote:
>> Move arch_init_copy_chip_data and arch_free_chip_data into function
>> pointers in struct irq_chip since they operate on irq_desc->chip_data.
>> 
>> arch_init_chip_data cannot be moved into struct irq_chip at this time
>> because irq_desc->chip is not known at the time the irq_desc is
>> setup. For now rename arch_init_chip_data to arch_init_irq_desc (for
>> PowerPC, the only other user, whose usage better matches the new name)
>> and on x86 convert arch_init_chip_data to x86_init_chip_data and
>> call this whenever a new struct irq_desc is allocated.
>> 
>> I've retained the chip_data behaviour for uv_irq although it isn't
>> clear to me if these interrupt types support migration or how closely
>> related to the APIC modes they really are. If it weren't for this the
>> x86_{init,copy,free}_chip_data functions could be static to
>> io_apic.c.
>> 
>> I've tested by booting on a 64 bit system, but it's not clear to me
>> what actions I need to take to actually exercise some of these code
>> paths.
>> 
>> Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
>> Acked-by: Michael Ellerman <michael@ellerman.id.au> [PowerPC rename portion]
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> Cc: Ingo Molnar <mingo@redhat.com>
>> Cc: H. Peter Anvin <hpa@zytor.com>
>> Cc: Eric W. Biederman <ebiederm@xmission.com>
>> Cc: Yinghai Lu <yinghai@kernel.org>
>> Cc: Jeremy Fitzhardinge <jeremy@goop.org>
>> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>> Cc: Paul Mackerras <paulus@samba.org>
>> Cc: x86@kernel.org
>> Cc: linuxppc-dev@ozlabs.org
>> Cc: linux-kernel@vger.kernel.org
>> ---
>>  arch/powerpc/kernel/irq.c      |    2 +-
>>  arch/x86/include/asm/hw_irq.h  |   11 +++++++-
>>  arch/x86/kernel/apic/io_apic.c |   58 +++++++++++++++++++++++++++++++++++++---
>>  arch/x86/kernel/uv_irq.c       |    5 +++
>>  include/linux/interrupt.h      |    2 +-
>>  include/linux/irq.h            |   12 +++++---
>>  kernel/irq/handle.c            |    2 +-
>>  kernel/irq/numa_migrate.c      |   12 +++++++-
>>  kernel/softirq.c               |    3 +-
>>  9 files changed, 91 insertions(+), 16 deletions(-)
>> 
>> diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
>> index 64f6f20..002d87f 100644
>> --- a/arch/powerpc/kernel/irq.c
>> +++ b/arch/powerpc/kernel/irq.c
>> @@ -1088,7 +1088,7 @@ int arch_early_irq_init(void)
>>  	return 0;
>>  }
>>  
>> -int arch_init_chip_data(struct irq_desc *desc, int node)
>> +int arch_init_irq_desc(struct irq_desc *desc, int node)
>>  {
>>  	desc->status |= IRQ_NOREQUEST;
>>  	return 0;
>> diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
>> index a929c9e..1bc7063 100644
>> --- a/arch/x86/include/asm/hw_irq.h
>> +++ b/arch/x86/include/asm/hw_irq.h
>> @@ -20,9 +20,9 @@
>>  #include <linux/percpu.h>
>>  #include <linux/profile.h>
>>  #include <linux/smp.h>
>> +#include <linux/irq.h>
>>  
>>  #include <asm/atomic.h>
>> -#include <asm/irq.h>
>>  #include <asm/sections.h>
>>  
>>  /* Interrupt handlers registered during init_IRQ */
>> @@ -61,6 +61,15 @@ extern void init_VISWS_APIC_irqs(void);
>>  extern void setup_IO_APIC(void);
>>  extern void disable_IO_APIC(void);
>>  
>> +extern int x86_init_chip_data(struct irq_desc *desc, int node);
>> +
>> +#ifdef CONFIG_SPARSE_IRQ
>> +extern void x86_copy_chip_data(struct irq_desc *old_desc,
>> +				  struct irq_desc *desc, int node);
>> +extern void x86_free_chip_data(struct irq_desc *old_desc,
>> +				  struct irq_desc *desc);
>> +#endif
>> +
>>  struct io_apic_irq_attr {
>>  	int ioapic;
>>  	int ioapic_pin;
>> diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
>> index e4e0ddc..12e5cf4 100644
>> --- a/arch/x86/kernel/apic/io_apic.c
>> +++ b/arch/x86/kernel/apic/io_apic.c
>> @@ -211,7 +211,7 @@ static struct irq_cfg *get_one_free_irq_cfg(int node)
>>  	return cfg;
>>  }
>>  
>> -int arch_init_chip_data(struct irq_desc *desc, int node)
>> +int x86_init_chip_data(struct irq_desc *desc, int node)
>>  {
>>  	struct irq_cfg *cfg;
>>  
>> @@ -287,8 +287,8 @@ static void free_irq_2_pin(struct irq_cfg *old_cfg, struct irq_cfg *cfg)
>>  	old_cfg->irq_2_pin = NULL;
>>  }
>>  
>> -void arch_init_copy_chip_data(struct irq_desc *old_desc,
>> -				 struct irq_desc *desc, int node)
>> +void x86_copy_chip_data(struct irq_desc *old_desc,
>> +			   struct irq_desc *desc, int node)
>>  {
>>  	struct irq_cfg *cfg;
>>  	struct irq_cfg *old_cfg;
>> @@ -312,7 +312,7 @@ static void free_irq_cfg(struct irq_cfg *old_cfg)
>>  	kfree(old_cfg);
>>  }
>>  
>> -void arch_free_chip_data(struct irq_desc *old_desc, struct irq_desc *desc)
>> +void x86_free_chip_data(struct irq_desc *old_desc, struct irq_desc *desc)
>>  {
>>  	struct irq_cfg *old_cfg, *cfg;
>>  
>> @@ -336,6 +336,11 @@ struct irq_cfg *irq_cfg(unsigned int irq)
>>  	return irq < nr_irqs ? irq_cfgx + irq : NULL;
>>  }
>>  
>> +int x86_init_chip_data(struct irq_desc *desc, int node)
>> +{
>> +	return 0;
>> +}
>> +
>
> you could put one dummy x86_copy_chip_data and x86_free_chip_data here too.
>
>>  #endif
>>  
>>  struct io_apic {
>> @@ -1520,6 +1525,7 @@ static void __init setup_IO_APIC_irqs(void)
>>  			printk(KERN_INFO "can not get irq_desc for %d\n", irq);
>>  			continue;
>>  		}
>> +		x86_init_chip_data(desc, node);
>>  		cfg = desc->chip_data;
>>  		add_pin_to_irq_node(cfg, node, apic_id, pin);
>>  		/*
>> @@ -1570,6 +1576,7 @@ void setup_IO_APIC_irq_extra(u32 gsi)
>>  		printk(KERN_INFO "can not get irq_desc for %d\n", irq);
>>  		return;
>>  	}
>> +	x86_init_chip_data(desc, node);
>>  
>>  	cfg = desc->chip_data;
>>  	add_pin_to_irq_node(cfg, node, apic_id, pin);
>> @@ -2739,6 +2746,11 @@ static struct irq_chip ioapic_chip __read_mostly = {
>>  	.set_affinity	= set_ioapic_affinity_irq,
>>  #endif
>>  	.retrigger	= ioapic_retrigger_irq,
>> +
>> +#ifdef CONFIG_SPARSE_IRQ
>> +	.copy_chip_data = x86_copy_chip_data,
>> +	.free_chip_data = x86_free_chip_data,
>> +#endif
>>  };
>>  
>>  static struct irq_chip ir_ioapic_chip __read_mostly = {
>> @@ -2754,6 +2766,11 @@ static struct irq_chip ir_ioapic_chip __read_mostly = {
>>  #endif
>>  #endif
>>  	.retrigger	= ioapic_retrigger_irq,
>> +
>> +#ifdef CONFIG_SPARSE_IRQ
>> +	.copy_chip_data = x86_copy_chip_data,
>> +	.free_chip_data = x86_free_chip_data,
>> +#endif
>>  };
>>  
>>  static inline void init_IO_APIC_traps(void)
>> @@ -3261,6 +3278,7 @@ unsigned int create_irq_nr(unsigned int irq_want, int node)
>>  			printk(KERN_INFO "can not get irq_desc for %d\n", new);
>>  			continue;
>>  		}
>> +		x86_init_chip_data(desc_new, node);
>>  		cfg_new = desc_new->chip_data;
>>  
>>  		if (cfg_new->vector != 0)
>> @@ -3466,6 +3484,11 @@ static struct irq_chip msi_chip = {
>>  	.set_affinity	= set_msi_irq_affinity,
>>  #endif
>>  	.retrigger	= ioapic_retrigger_irq,
>> +
>> +#ifdef CONFIG_SPARSE_IRQ
>> +	.copy_chip_data = x86_copy_chip_data,
>> +	.free_chip_data = x86_free_chip_data,
>> +#endif
>>  };
>>  
>>  static struct irq_chip msi_ir_chip = {
>> @@ -3479,6 +3502,11 @@ static struct irq_chip msi_ir_chip = {
>>  #endif
>>  #endif
>>  	.retrigger	= ioapic_retrigger_irq,
>> +
>> +#ifdef CONFIG_SPARSE_IRQ
>> +	.copy_chip_data = x86_copy_chip_data,
>> +	.free_chip_data = x86_free_chip_data,
>> +#endif
>>  };
>>  
>>  /*
>> @@ -3638,6 +3666,11 @@ static struct irq_chip dmar_msi_type = {
>>  	.set_affinity = dmar_msi_set_affinity,
>>  #endif
>>  	.retrigger = ioapic_retrigger_irq,
>> +
>> +#ifdef CONFIG_SPARSE_IRQ
>> +	.copy_chip_data = x86_copy_chip_data,
>> +	.free_chip_data = x86_free_chip_data,
>> +#endif
>>  };
>>  
>>  int arch_setup_dmar_msi(unsigned int irq)
>> @@ -3695,6 +3728,11 @@ static struct irq_chip ir_hpet_msi_type = {
>>  #endif
>>  #endif
>>  	.retrigger = ioapic_retrigger_irq,
>> +
>> +#ifdef CONFIG_SPARSE_IRQ
>> +	.copy_chip_data = x86_copy_chip_data,
>> +	.free_chip_data = x86_free_chip_data,
>> +#endif
>>  };
>>  
>>  static struct irq_chip hpet_msi_type = {
>> @@ -3706,6 +3744,11 @@ static struct irq_chip hpet_msi_type = {
>>  	.set_affinity = hpet_msi_set_affinity,
>>  #endif
>>  	.retrigger = ioapic_retrigger_irq,
>> +
>> +#ifdef CONFIG_SPARSE_IRQ
>> +	.copy_chip_data = x86_copy_chip_data,
>> +	.free_chip_data = x86_free_chip_data,
>> +#endif
>>  };
>>  
>>  int arch_setup_hpet_msi(unsigned int irq, unsigned int id)
>> @@ -3792,6 +3835,11 @@ static struct irq_chip ht_irq_chip = {
>>  	.set_affinity	= set_ht_irq_affinity,
>>  #endif
>>  	.retrigger	= ioapic_retrigger_irq,
>> +
>> +#ifdef CONFIG_SPARSE_IRQ
>> +	.copy_chip_data = x86_copy_chip_data,
>> +	.free_chip_data = x86_free_chip_data,
>> +#endif
>>  };
>>  
>>  int arch_setup_ht_irq(unsigned int irq, struct pci_dev *dev)
>> @@ -3919,6 +3967,7 @@ static int __io_apic_set_pci_routing(struct device *dev, int irq,
>>  		printk(KERN_INFO "can not get irq_desc %d\n", irq);
>>  		return 0;
>>  	}
>> +	x86_init_chip_data(desc, node);
>>  
>>  	pin = irq_attr->ioapic_pin;
>>  	trigger = irq_attr->trigger;
>> @@ -4313,6 +4362,7 @@ void __init pre_init_apic_IRQ0(void)
>>  	phys_cpu_present_map = physid_mask_of_physid(boot_cpu_physical_apicid);
>>  #endif
>>  	desc = irq_to_desc_alloc_node(0, 0);
>> +	x86_init_chip_data(desc, 0);
>>  
>>  	setup_local_APIC();
>>  
>> diff --git a/arch/x86/kernel/uv_irq.c b/arch/x86/kernel/uv_irq.c
>> index ece73d8..df2c6d6 100644
>> --- a/arch/x86/kernel/uv_irq.c
>> +++ b/arch/x86/kernel/uv_irq.c
>> @@ -55,6 +55,11 @@ struct irq_chip uv_irq_chip = {
>>  	.eoi		= uv_ack_apic,
>>  	.end		= uv_noop,
>>  	.set_affinity	= uv_set_irq_affinity,
>> +
>> +#ifdef CONFIG_SPARSE_IRQ
>> +	.copy_chip_data = x86_copy_chip_data,
>> +	.free_chip_data = x86_free_chip_data,
>> +#endif
>>  };
>>  
>>  /*
>> diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
>> index 75f3f00..cc4cd22 100644
>> --- a/include/linux/interrupt.h
>> +++ b/include/linux/interrupt.h
>> @@ -611,6 +611,6 @@ struct irq_desc;
>>  extern int early_irq_init(void);
>>  extern int arch_probe_nr_irqs(void);
>>  extern int arch_early_irq_init(void);
>> -extern int arch_init_chip_data(struct irq_desc *desc, int node);
>> +extern int arch_init_irq_desc(struct irq_desc *desc, int node);
>>  
>>  #endif
>> diff --git a/include/linux/irq.h b/include/linux/irq.h
>> index 707ab12..558bd2d 100644
>> --- a/include/linux/irq.h
>> +++ b/include/linux/irq.h
>> @@ -131,6 +131,14 @@ struct irq_chip {
>>  	void		(*bus_lock)(unsigned int irq);
>>  	void		(*bus_sync_unlock)(unsigned int irq);
>>  
>> +	/* for move_irq_desc */
>> +#ifdef CONFIG_SPARSE_IRQ
>> +	void 		(*copy_chip_data)(struct irq_desc *old_desc,
>> +					  struct irq_desc *desc, int node);
>> +	void		(*free_chip_data)(struct irq_desc *old_desc,
>> +					  struct irq_desc *desc);
>> +#endif
>> +
>>  	/* Currently used only by UML, might disappear one day.*/
>>  #ifdef CONFIG_IRQ_RELEASE_METHOD
>>  	void		(*release)(unsigned int irq, void *dev_id);
>> @@ -208,10 +216,6 @@ struct irq_desc {
>>  	const char		*name;
>>  } ____cacheline_internodealigned_in_smp;
>>  
>> -extern void arch_init_copy_chip_data(struct irq_desc *old_desc,
>> -					struct irq_desc *desc, int node);
>> -extern void arch_free_chip_data(struct irq_desc *old_desc, struct irq_desc *desc);
>> -
>>  #ifndef CONFIG_SPARSE_IRQ
>>  extern struct irq_desc irq_desc[NR_IRQS];
>>  #endif
>> diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
>> index 76d5a67..168e2f8 100644
>> --- a/kernel/irq/handle.c
>> +++ b/kernel/irq/handle.c
>> @@ -120,7 +120,6 @@ static void init_one_irq_desc(int irq, struct irq_desc *desc, int node)
>>  		BUG_ON(1);
>>  	}
>>  	init_desc_masks(desc);
>> -	arch_init_chip_data(desc, node);
>>  }
>>  
>>  /*
>> @@ -228,6 +227,7 @@ struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)
>>  		BUG_ON(1);
>>  	}
>>  	init_one_irq_desc(irq, desc, node);
>> +	arch_init_irq_desc(desc, node);
>
> you move out init_chip_data for x86 out of irq_to_desc_alloc_node
> current init_chip_data in irq_to_desc_alloc_node is protected by sparse_irq_lock.
>
>
> wonder if you could let arch_init_irq_desc for x86 to call x86_init_chip_data?
>
> or let add another irq_to_desc_alloc_node_f to take extra func call.
>
> like 
> typedef int (*init_chip_data_f)(struct irq_desc *desc, int node);
> struct irq_desc * __ref irq_to_desc_alloc_node_f(unsigned int irq, int node, init_chip_data_f *f);
>
> struct irq_desc * __ref irq_to_desc_alloc_node_f(unsigned int irq, int node)
> {
>  irq_to_desc_alloc_node(irq, node, NULL);
> }
>
> then for x86
>
> int arch_init_irq_desc(struct irq_desc *desc, int node, init_chip_data_f *f)
> {
> 	if (!f)
> 		return x86_init_chip_data(desc, node);
>  	f(desc, node);
> }
>
> after that xen could use
> irq_to_desc_alloc_node_f(irq, node, xen_init_chip_data);
>
> as need...
>
> at last we don't need to call x86_init_chip_data everywhere.

Either that or we could have an arch specific wrapper say
"x86_irq_to_desc_alloc_node" that simply wraps irq_to_desc_alloc_node,
with the little extras we need.  This assumes that none of the
initialization has to happen inside of the lock an arch specific
wrapper makes sense.

Let's evaluate this set of patches on it's merits.  What this patchset
allows is a Xen implementation whose irq functions are fully decoupled
from the rest of x86 that supports SPARSE_IRQ.    That is a huge
maintenance improvement that far outweighs the worst damage this
patch can do to maintenance.

So trying to evaluate races.  The worse case for this particular piece
of code appears to be create_irq_nr.  As this is the only place where
we are setting up irqs and possibly repurposing the structure.  Today
we figure out if an irq has been assigned by looking at irq_cfg->vector,
and if it is non-zero the irq has been assigned.

The logic in x86_init_chip_data is correct we only assign desc->chip_data
if the generic layers are above it.  However we need a lock to ensure that
two paths don't race in that comparison and that assignment.  There is
no lock in x86_init_chip_data.  Which unfortunately means as it stands
this patchset is buggy.

Eric
Ian Campbell - March 16, 2010, 8:50 a.m.
On Sat, 2010-03-13 at 00:29 +0000, Eric W. Biederman wrote: 
> [...]
> > after that xen could use
> > irq_to_desc_alloc_node_f(irq, node, xen_init_chip_data);
> >
> > as need...
> >
> > at last we don't need to call x86_init_chip_data everywhere.

This was one of the things I was considering. It seems like one of the
easiest solutions to make work correctly with the current locking in
e.g. irq_to_desc_alloc_node since the callback would always happen under
the lock taken in that function.

> So trying to evaluate races.  The worse case for this particular piece
> of code appears to be create_irq_nr.  As this is the only place where
> we are setting up irqs and possibly repurposing the structure.

Yes, create_irq_nr was one of the functions I was struggling to solve
cleanly. There is a similar construct in the Xen code as well.

Part of the problem I'm having is the combination of lookup and allocate
in irq_to_desc_alloc_node but also the kind of "implicit" repurposing is
tricky to deal with. (by implicit I just mean that I can't find where
the previous user explicitly says they are finished with it, if you see
what I mean)

What do you think of adding an explicit free operation for the irq_desc
structs? (does one already exist? I couldn't find it). This would go
along with some tracking of allocation state, trivial in the sparse case
where you can treat a NULL node in the radix tree as unallocated, I
guess a flag would suffice in the static array non-sparse case?

Going further could we split the alloc and lookup functions into
separate operations instead of combining them in irq_to_desc_alloc_node?
We already have irq_to_desc for the lookup portion so this would largely
involve changes to the semantics of irq_to_desc_alloc_node, perhaps
returning ERR_PTR(-EBUSY) if the node was already allocated.

Having a variant which found a free IRQ rather than operating on a
specific requested IRQ could also be useful for create_irq_nr as well as
find_unbound_irq on the Xen side. I'm not convinced irq_alloc_virt on
powerpc isn't implementing broadly the same concept as well, although it
seems to work very differently from the other two.

>   Today
> we figure out if an irq has been assigned by looking at irq_cfg->vector,
> and if it is non-zero the irq has been assigned.

Which is tricky to move into generic code hence my suggestions of
explicitly freeing the irq_desc and tracking the allocation status in
the generic code. 

> The logic in x86_init_chip_data is correct we only assign desc->chip_data
> if the generic layers are above it.  However we need a lock to ensure that
> two paths don't race in that comparison and that assignment.  There is
> no lock in x86_init_chip_data.  Which unfortunately means as it stands
> this patchset is buggy.

Yes, unfortunately I think you are right. The callback idea fixes this.
I'll respin with that.

Ian.
Eric W. Biederman - March 16, 2010, 9:18 a.m.
Ian Campbell <Ian.Campbell@citrix.com> writes:

> On Sat, 2010-03-13 at 00:29 +0000, Eric W. Biederman wrote: 
>> [...]
>> > after that xen could use
>> > irq_to_desc_alloc_node_f(irq, node, xen_init_chip_data);
>> >
>> > as need...
>> >
>> > at last we don't need to call x86_init_chip_data everywhere.
>
> This was one of the things I was considering. It seems like one of the
> easiest solutions to make work correctly with the current locking in
> e.g. irq_to_desc_alloc_node since the callback would always happen under
> the lock taken in that function.
>
>> So trying to evaluate races.  The worse case for this particular piece
>> of code appears to be create_irq_nr.  As this is the only place where
>> we are setting up irqs and possibly repurposing the structure.
>
> Yes, create_irq_nr was one of the functions I was struggling to solve
> cleanly. There is a similar construct in the Xen code as well.
>
> Part of the problem I'm having is the combination of lookup and allocate
> in irq_to_desc_alloc_node but also the kind of "implicit" repurposing is
> tricky to deal with. (by implicit I just mean that I can't find where
> the previous user explicitly says they are finished with it, if you see
> what I mean)
>
> What do you think of adding an explicit free operation for the irq_desc
> structs? (does one already exist? I couldn't find it). This would go
> along with some tracking of allocation state, trivial in the sparse case
> where you can treat a NULL node in the radix tree as unallocated, I
> guess a flag would suffice in the static array non-sparse case?

We have free_one_irq_desc used in the numa irq migration code.
We have dynamic_irq_cleanup.

I don't expect it would be fundamentally hard to put all of the pieces
together.

> Going further could we split the alloc and lookup functions into
> separate operations instead of combining them in irq_to_desc_alloc_node?
> We already have irq_to_desc for the lookup portion so this would largely
> involve changes to the semantics of irq_to_desc_alloc_node, perhaps
> returning ERR_PTR(-EBUSY) if the node was already allocated.
>
> Having a variant which found a free IRQ rather than operating on a
> specific requested IRQ could also be useful for create_irq_nr as well as
> find_unbound_irq on the Xen side. I'm not convinced irq_alloc_virt on
> powerpc isn't implementing broadly the same concept as well, although it
> seems to work very differently from the other two.
>
>>   Today
>> we figure out if an irq has been assigned by looking at irq_cfg->vector,
>> and if it is non-zero the irq has been assigned.
>
> Which is tricky to move into generic code hence my suggestions of
> explicitly freeing the irq_desc and tracking the allocation status in
> the generic code. 

Agreed.  Getting an allocation assist into the generic code sounds
nlike something for the next round of patches after your current one.
At least for msi irqs, hi irqs and other irqs that are totally software
constructs this makes a lot of sense.

We really need to get to the point on x86 where sparse irq has no penalties
and stop making it an option.  Otherwise it gets a bit tricky to rely
on sparse irq for an allocation helper.

I need to go look up my old patchset.  I did something different with
create_irq(), that I think was cleaner and it may be worth resurrecting.
At the very least I generalized the msi case and the ht irq case into
using the same pointer in struct irq_desc.

>> The logic in x86_init_chip_data is correct we only assign desc->chip_data
>> if the generic layers are above it.  However we need a lock to ensure that
>> two paths don't race in that comparison and that assignment.  There is
>> no lock in x86_init_chip_data.  Which unfortunately means as it stands
>> this patchset is buggy.
>
> Yes, unfortunately I think you are right. The callback idea fixes this.
> I'll respin with that.

Thanks.

Eric

Patch

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 64f6f20..002d87f 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -1088,7 +1088,7 @@  int arch_early_irq_init(void)
 	return 0;
 }
 
-int arch_init_chip_data(struct irq_desc *desc, int node)
+int arch_init_irq_desc(struct irq_desc *desc, int node)
 {
 	desc->status |= IRQ_NOREQUEST;
 	return 0;
diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
index a929c9e..1bc7063 100644
--- a/arch/x86/include/asm/hw_irq.h
+++ b/arch/x86/include/asm/hw_irq.h
@@ -20,9 +20,9 @@ 
 #include <linux/percpu.h>
 #include <linux/profile.h>
 #include <linux/smp.h>
+#include <linux/irq.h>
 
 #include <asm/atomic.h>
-#include <asm/irq.h>
 #include <asm/sections.h>
 
 /* Interrupt handlers registered during init_IRQ */
@@ -61,6 +61,15 @@  extern void init_VISWS_APIC_irqs(void);
 extern void setup_IO_APIC(void);
 extern void disable_IO_APIC(void);
 
+extern int x86_init_chip_data(struct irq_desc *desc, int node);
+
+#ifdef CONFIG_SPARSE_IRQ
+extern void x86_copy_chip_data(struct irq_desc *old_desc,
+				  struct irq_desc *desc, int node);
+extern void x86_free_chip_data(struct irq_desc *old_desc,
+				  struct irq_desc *desc);
+#endif
+
 struct io_apic_irq_attr {
 	int ioapic;
 	int ioapic_pin;
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index e4e0ddc..12e5cf4 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -211,7 +211,7 @@  static struct irq_cfg *get_one_free_irq_cfg(int node)
 	return cfg;
 }
 
-int arch_init_chip_data(struct irq_desc *desc, int node)
+int x86_init_chip_data(struct irq_desc *desc, int node)
 {
 	struct irq_cfg *cfg;
 
@@ -287,8 +287,8 @@  static void free_irq_2_pin(struct irq_cfg *old_cfg, struct irq_cfg *cfg)
 	old_cfg->irq_2_pin = NULL;
 }
 
-void arch_init_copy_chip_data(struct irq_desc *old_desc,
-				 struct irq_desc *desc, int node)
+void x86_copy_chip_data(struct irq_desc *old_desc,
+			   struct irq_desc *desc, int node)
 {
 	struct irq_cfg *cfg;
 	struct irq_cfg *old_cfg;
@@ -312,7 +312,7 @@  static void free_irq_cfg(struct irq_cfg *old_cfg)
 	kfree(old_cfg);
 }
 
-void arch_free_chip_data(struct irq_desc *old_desc, struct irq_desc *desc)
+void x86_free_chip_data(struct irq_desc *old_desc, struct irq_desc *desc)
 {
 	struct irq_cfg *old_cfg, *cfg;
 
@@ -336,6 +336,11 @@  struct irq_cfg *irq_cfg(unsigned int irq)
 	return irq < nr_irqs ? irq_cfgx + irq : NULL;
 }
 
+int x86_init_chip_data(struct irq_desc *desc, int node)
+{
+	return 0;
+}
+
 #endif
 
 struct io_apic {
@@ -1520,6 +1525,7 @@  static void __init setup_IO_APIC_irqs(void)
 			printk(KERN_INFO "can not get irq_desc for %d\n", irq);
 			continue;
 		}
+		x86_init_chip_data(desc, node);
 		cfg = desc->chip_data;
 		add_pin_to_irq_node(cfg, node, apic_id, pin);
 		/*
@@ -1570,6 +1576,7 @@  void setup_IO_APIC_irq_extra(u32 gsi)
 		printk(KERN_INFO "can not get irq_desc for %d\n", irq);
 		return;
 	}
+	x86_init_chip_data(desc, node);
 
 	cfg = desc->chip_data;
 	add_pin_to_irq_node(cfg, node, apic_id, pin);
@@ -2739,6 +2746,11 @@  static struct irq_chip ioapic_chip __read_mostly = {
 	.set_affinity	= set_ioapic_affinity_irq,
 #endif
 	.retrigger	= ioapic_retrigger_irq,
+
+#ifdef CONFIG_SPARSE_IRQ
+	.copy_chip_data = x86_copy_chip_data,
+	.free_chip_data = x86_free_chip_data,
+#endif
 };
 
 static struct irq_chip ir_ioapic_chip __read_mostly = {
@@ -2754,6 +2766,11 @@  static struct irq_chip ir_ioapic_chip __read_mostly = {
 #endif
 #endif
 	.retrigger	= ioapic_retrigger_irq,
+
+#ifdef CONFIG_SPARSE_IRQ
+	.copy_chip_data = x86_copy_chip_data,
+	.free_chip_data = x86_free_chip_data,
+#endif
 };
 
 static inline void init_IO_APIC_traps(void)
@@ -3261,6 +3278,7 @@  unsigned int create_irq_nr(unsigned int irq_want, int node)
 			printk(KERN_INFO "can not get irq_desc for %d\n", new);
 			continue;
 		}
+		x86_init_chip_data(desc_new, node);
 		cfg_new = desc_new->chip_data;
 
 		if (cfg_new->vector != 0)
@@ -3466,6 +3484,11 @@  static struct irq_chip msi_chip = {
 	.set_affinity	= set_msi_irq_affinity,
 #endif
 	.retrigger	= ioapic_retrigger_irq,
+
+#ifdef CONFIG_SPARSE_IRQ
+	.copy_chip_data = x86_copy_chip_data,
+	.free_chip_data = x86_free_chip_data,
+#endif
 };
 
 static struct irq_chip msi_ir_chip = {
@@ -3479,6 +3502,11 @@  static struct irq_chip msi_ir_chip = {
 #endif
 #endif
 	.retrigger	= ioapic_retrigger_irq,
+
+#ifdef CONFIG_SPARSE_IRQ
+	.copy_chip_data = x86_copy_chip_data,
+	.free_chip_data = x86_free_chip_data,
+#endif
 };
 
 /*
@@ -3638,6 +3666,11 @@  static struct irq_chip dmar_msi_type = {
 	.set_affinity = dmar_msi_set_affinity,
 #endif
 	.retrigger = ioapic_retrigger_irq,
+
+#ifdef CONFIG_SPARSE_IRQ
+	.copy_chip_data = x86_copy_chip_data,
+	.free_chip_data = x86_free_chip_data,
+#endif
 };
 
 int arch_setup_dmar_msi(unsigned int irq)
@@ -3695,6 +3728,11 @@  static struct irq_chip ir_hpet_msi_type = {
 #endif
 #endif
 	.retrigger = ioapic_retrigger_irq,
+
+#ifdef CONFIG_SPARSE_IRQ
+	.copy_chip_data = x86_copy_chip_data,
+	.free_chip_data = x86_free_chip_data,
+#endif
 };
 
 static struct irq_chip hpet_msi_type = {
@@ -3706,6 +3744,11 @@  static struct irq_chip hpet_msi_type = {
 	.set_affinity = hpet_msi_set_affinity,
 #endif
 	.retrigger = ioapic_retrigger_irq,
+
+#ifdef CONFIG_SPARSE_IRQ
+	.copy_chip_data = x86_copy_chip_data,
+	.free_chip_data = x86_free_chip_data,
+#endif
 };
 
 int arch_setup_hpet_msi(unsigned int irq, unsigned int id)
@@ -3792,6 +3835,11 @@  static struct irq_chip ht_irq_chip = {
 	.set_affinity	= set_ht_irq_affinity,
 #endif
 	.retrigger	= ioapic_retrigger_irq,
+
+#ifdef CONFIG_SPARSE_IRQ
+	.copy_chip_data = x86_copy_chip_data,
+	.free_chip_data = x86_free_chip_data,
+#endif
 };
 
 int arch_setup_ht_irq(unsigned int irq, struct pci_dev *dev)
@@ -3919,6 +3967,7 @@  static int __io_apic_set_pci_routing(struct device *dev, int irq,
 		printk(KERN_INFO "can not get irq_desc %d\n", irq);
 		return 0;
 	}
+	x86_init_chip_data(desc, node);
 
 	pin = irq_attr->ioapic_pin;
 	trigger = irq_attr->trigger;
@@ -4313,6 +4362,7 @@  void __init pre_init_apic_IRQ0(void)
 	phys_cpu_present_map = physid_mask_of_physid(boot_cpu_physical_apicid);
 #endif
 	desc = irq_to_desc_alloc_node(0, 0);
+	x86_init_chip_data(desc, 0);
 
 	setup_local_APIC();
 
diff --git a/arch/x86/kernel/uv_irq.c b/arch/x86/kernel/uv_irq.c
index ece73d8..df2c6d6 100644
--- a/arch/x86/kernel/uv_irq.c
+++ b/arch/x86/kernel/uv_irq.c
@@ -55,6 +55,11 @@  struct irq_chip uv_irq_chip = {
 	.eoi		= uv_ack_apic,
 	.end		= uv_noop,
 	.set_affinity	= uv_set_irq_affinity,
+
+#ifdef CONFIG_SPARSE_IRQ
+	.copy_chip_data = x86_copy_chip_data,
+	.free_chip_data = x86_free_chip_data,
+#endif
 };
 
 /*
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 75f3f00..cc4cd22 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -611,6 +611,6 @@  struct irq_desc;
 extern int early_irq_init(void);
 extern int arch_probe_nr_irqs(void);
 extern int arch_early_irq_init(void);
-extern int arch_init_chip_data(struct irq_desc *desc, int node);
+extern int arch_init_irq_desc(struct irq_desc *desc, int node);
 
 #endif
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 707ab12..558bd2d 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -131,6 +131,14 @@  struct irq_chip {
 	void		(*bus_lock)(unsigned int irq);
 	void		(*bus_sync_unlock)(unsigned int irq);
 
+	/* for move_irq_desc */
+#ifdef CONFIG_SPARSE_IRQ
+	void 		(*copy_chip_data)(struct irq_desc *old_desc,
+					  struct irq_desc *desc, int node);
+	void		(*free_chip_data)(struct irq_desc *old_desc,
+					  struct irq_desc *desc);
+#endif
+
 	/* Currently used only by UML, might disappear one day.*/
 #ifdef CONFIG_IRQ_RELEASE_METHOD
 	void		(*release)(unsigned int irq, void *dev_id);
@@ -208,10 +216,6 @@  struct irq_desc {
 	const char		*name;
 } ____cacheline_internodealigned_in_smp;
 
-extern void arch_init_copy_chip_data(struct irq_desc *old_desc,
-					struct irq_desc *desc, int node);
-extern void arch_free_chip_data(struct irq_desc *old_desc, struct irq_desc *desc);
-
 #ifndef CONFIG_SPARSE_IRQ
 extern struct irq_desc irq_desc[NR_IRQS];
 #endif
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 76d5a67..168e2f8 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -120,7 +120,6 @@  static void init_one_irq_desc(int irq, struct irq_desc *desc, int node)
 		BUG_ON(1);
 	}
 	init_desc_masks(desc);
-	arch_init_chip_data(desc, node);
 }
 
 /*
@@ -228,6 +227,7 @@  struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)
 		BUG_ON(1);
 	}
 	init_one_irq_desc(irq, desc, node);
+	arch_init_irq_desc(desc, node);
 
 	set_irq_desc(irq, desc);
 
diff --git a/kernel/irq/numa_migrate.c b/kernel/irq/numa_migrate.c
index 963559d..9ea09c9 100644
--- a/kernel/irq/numa_migrate.c
+++ b/kernel/irq/numa_migrate.c
@@ -47,7 +47,8 @@  static bool init_copy_one_irq_desc(int irq, struct irq_desc *old_desc,
 	lockdep_set_class(&desc->lock, &irq_desc_lock_class);
 	init_copy_kstat_irqs(old_desc, desc, node, nr_cpu_ids);
 	init_copy_desc_masks(old_desc, desc);
-	arch_init_copy_chip_data(old_desc, desc, node);
+	if (desc->chip->copy_chip_data)
+		desc->chip->copy_chip_data(old_desc, desc, node);
 	return true;
 }
 
@@ -55,7 +56,8 @@  static void free_one_irq_desc(struct irq_desc *old_desc, struct irq_desc *desc)
 {
 	free_kstat_irqs(old_desc, desc);
 	free_desc_masks(old_desc, desc);
-	arch_free_chip_data(old_desc, desc);
+	if (desc->chip->free_chip_data)
+		desc->chip->free_chip_data(old_desc, desc);
 }
 
 static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
@@ -107,9 +109,15 @@  out_unlock:
 
 struct irq_desc *move_irq_desc(struct irq_desc *desc, int node)
 {
+
 	/* those static or target node is -1, do not move them */
 	if (desc->irq < NR_IRQS_LEGACY || node == -1)
 		return desc;
+	/* IRQ chip does not support movement */
+	if (desc->chip_data &&
+	    (desc->chip->copy_chip_data == NULL ||
+	     desc->chip->free_chip_data == NULL))
+		return desc;
 
 	if (desc->node != node)
 		desc = __real_move_irq_desc(desc, node);
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 7c1a67e..3f4b80e 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -895,8 +895,7 @@  int __init __weak arch_early_irq_init(void)
 {
 	return 0;
 }
-
-int __weak arch_init_chip_data(struct irq_desc *desc, int node)
+int __weak arch_init_irq_desc(struct irq_desc *desc, int node)
 {
 	return 0;
 }