Re: tick-common.c hack for s390 needed

[Thomas Gleixner <tglx@linutronix.de>]

On Sun, 23 Mar 2008, Russell King wrote:

> On Sat, Mar 22, 2008 at 09:32:23PM +0100, Heiko Carstens wrote:
> > Generic code is not supposed to include irq.h. Replace this include
> > by linux/hardirq.h instead and add/replace an include of linux/irq.h
> > in asm header files where necessary.
> > This change should only matter for architectures that make use of
> > GENERIC_CLOCKEVENTS.
> > Architectures in question are mips, x86, arm, sh, powerpc, uml and sparc64.
> > 
> > I did some cross compile tests for mips, x86_64, arm, powerpc and sparc64.
> > This patch fixes also build breakages caused by the include replacement in
> > tick-common.h.
> 
> I generally dislike adding optional linux/* includes in asm/* includes -
> I'm nervous about this causing include loops.
> 
> However, there's a separate point to be discussed here.
> 
> That is, what interfaces are expected of every architecture in the kernel.
> If generic code wants to be able to set the affinity of interrupts, then
> that needs to become part of the interfaces listed in linux/interrupt.h
> rather than linux/irq.h.
> 
> So what I suggest is this approach instead (against Linus' tree of a
> couple of days ago) - we move irq_set_affinity() and irq_can_set_affinity()
> to linux/interrupt.h, change the linux/irq.h includes to linux/interrupt.h
> and include asm/irq_regs.h where needed (asm/irq_regs.h is supposed to be
> rarely used include since not much touches the stacked parent context
> registers.)

That patch makes a lot of sense and resolves all the issues. 

I push it through hrt.git and add the GENERIC_HARDIRQS dependency
which was requested by Heiko.

Thanks,

	tglx

> Build tested on ARM PXA family kernels and ARM's Realview platform
> kernels which both use genirq.
>
> diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
> index f8ab4ce..355e3b0 100644
> --- a/include/linux/interrupt.h
> +++ b/include/linux/interrupt.h
> @@ -102,6 +102,25 @@ extern void disable_irq_nosync(unsigned int irq);
>  extern void disable_irq(unsigned int irq);
>  extern void enable_irq(unsigned int irq);
>  
> +#ifdef CONFIG_SMP
> +
> +extern int irq_set_affinity(unsigned int irq, cpumask_t cpumask);
> +extern int irq_can_set_affinity(unsigned int irq);
> +
> +#else /* CONFIG_SMP */
> +
> +static inline int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
> +{
> +	return -EINVAL;
> +}
> +
> +static inline int irq_can_set_affinity(unsigned int irq)
> +{
> +	return 0;
> +}
> +
> +#endif /* CONFIG_SMP */
> +
>  #ifdef CONFIG_GENERIC_HARDIRQS
>  /*
>   * Special lockdep variants of irq disabling/enabling.
> diff --git a/include/linux/irq.h b/include/linux/irq.h
> index 176e5e7..1883a85 100644
> --- a/include/linux/irq.h
> +++ b/include/linux/irq.h
> @@ -228,21 +228,11 @@ static inline void set_pending_irq(unsigned int irq, cpumask_t mask)
>  
>  #endif /* CONFIG_GENERIC_PENDING_IRQ */
>  
> -extern int irq_set_affinity(unsigned int irq, cpumask_t cpumask);
> -extern int irq_can_set_affinity(unsigned int irq);
> -
>  #else /* CONFIG_SMP */
>  
>  #define move_native_irq(x)
>  #define move_masked_irq(x)
>  
> -static inline int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
> -{
> -	return -EINVAL;
> -}
> -
> -static inline int irq_can_set_affinity(unsigned int irq) { return 0; }
> -
>  #endif /* CONFIG_SMP */
>  
>  #ifdef CONFIG_IRQBALANCE
> diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
> index e1bd50c..fdfa0c7 100644
> --- a/kernel/time/tick-broadcast.c
> +++ b/kernel/time/tick-broadcast.c
> @@ -14,7 +14,7 @@
>  #include <linux/cpu.h>
>  #include <linux/err.h>
>  #include <linux/hrtimer.h>
> -#include <linux/irq.h>
> +#include <linux/interrupt.h>
>  #include <linux/percpu.h>
>  #include <linux/profile.h>
>  #include <linux/sched.h>
> diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
> index 1bea399..4f38865 100644
> --- a/kernel/time/tick-common.c
> +++ b/kernel/time/tick-common.c
> @@ -14,12 +14,14 @@
>  #include <linux/cpu.h>
>  #include <linux/err.h>
>  #include <linux/hrtimer.h>
> -#include <linux/irq.h>
> +#include <linux/interrupt.h>
>  #include <linux/percpu.h>
>  #include <linux/profile.h>
>  #include <linux/sched.h>
>  #include <linux/tick.h>
>  
> +#include <asm/irq_regs.h>
> +
>  #include "tick-internal.h"
>  
>  /*
> diff --git a/kernel/time/tick-oneshot.c b/kernel/time/tick-oneshot.c
> index 0258d31..450c049 100644
> --- a/kernel/time/tick-oneshot.c
> +++ b/kernel/time/tick-oneshot.c
> @@ -14,7 +14,7 @@
>  #include <linux/cpu.h>
>  #include <linux/err.h>
>  #include <linux/hrtimer.h>
> -#include <linux/irq.h>
> +#include <linux/interrupt.h>
>  #include <linux/percpu.h>
>  #include <linux/profile.h>
>  #include <linux/sched.h>
> 
> 
> -- 
> Russell King
>  Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
>  maintainer of:
>