2005-04-16 16:20:36 -06:00
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/*
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* linux/arch/arm/kernel/irq.c
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*
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* Copyright (C) 1992 Linus Torvalds
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* Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
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*
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2005-06-25 12:39:45 -06:00
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* Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation.
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* Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and
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* Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>.
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*
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2005-04-16 16:20:36 -06:00
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This file contains the code used by various IRQ handling routines:
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* asking for different IRQ's should be done through these routines
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* instead of just grabbing them. Thus setups with different IRQ numbers
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* shouldn't result in any weird surprises, and installing new handlers
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* should be easier.
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*
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* IRQ's are in fact implemented a bit like signal handlers for the kernel.
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* Naturally it's not a 1:1 relation, but there are similarities.
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*/
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#include <linux/kernel_stat.h>
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#include <linux/signal.h>
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#include <linux/ioport.h>
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#include <linux/interrupt.h>
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2006-07-01 15:30:09 -06:00
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#include <linux/irq.h>
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2005-04-16 16:20:36 -06:00
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#include <linux/random.h>
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#include <linux/smp.h>
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#include <linux/init.h>
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#include <linux/seq_file.h>
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#include <linux/errno.h>
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#include <linux/list.h>
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#include <linux/kallsyms.h>
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#include <linux/proc_fs.h>
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2011-10-08 04:20:42 -06:00
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#include <asm/exception.h>
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2005-04-16 16:20:36 -06:00
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#include <asm/system.h>
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2010-12-20 03:18:36 -07:00
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#include <asm/mach/arch.h>
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2008-08-03 08:04:04 -06:00
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#include <asm/mach/irq.h>
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2005-06-25 12:39:45 -06:00
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#include <asm/mach/time.h>
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2005-04-16 16:20:36 -06:00
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/*
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* No architecture-specific irq_finish function defined in arm/arch/irqs.h.
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*/
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#ifndef irq_finish
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#define irq_finish(irq) do { } while (0)
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#endif
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2006-07-01 15:30:09 -06:00
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unsigned long irq_err_count;
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2005-04-16 16:20:36 -06:00
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2011-03-24 05:02:11 -06:00
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int arch_show_interrupts(struct seq_file *p, int prec)
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2005-04-16 16:20:36 -06:00
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{
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2009-08-03 08:11:29 -06:00
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#ifdef CONFIG_FIQ
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2011-03-24 05:02:11 -06:00
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show_fiq_list(p, prec);
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2005-04-16 16:20:36 -06:00
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#endif
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#ifdef CONFIG_SMP
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2011-03-24 05:02:11 -06:00
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show_ipi_list(p, prec);
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2005-04-16 16:20:36 -06:00
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#endif
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2011-03-24 05:02:11 -06:00
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seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
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2005-04-16 16:20:36 -06:00
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return 0;
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}
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/*
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ARM: introduce handle_IRQ() not to dump exception stack
On Mon, Jul 11, 2011 at 3:52 PM, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:
...
> The __exception annotation on a function causes this to happen:
>
> [<c002406c>] (asm_do_IRQ+0x6c/0x8c) from [<c0024b84>]
> (__irq_svc+0x44/0xcc)
> Exception stack(0xc3897c78 to 0xc3897cc0)
> 7c60: 4022d320 4022e000
> 7c80: 08000075 00001000 c32273c0 c03ce1c0 c2b49b78 4022d000 c2b420b4 00000001
> 7ca0: 00000000 c3897cfc 00000000 c3897cc0 c00afc54 c002edd8 00000013 ffffffff
>
> Where that stack dump represents the pt_regs for the exception which
> happened. Any function found in while unwinding will cause this to
> be printed.
>
> If you insert a C function between the IRQ assembly and asm_do_IRQ,
> the
> dump you get from asm_do_IRQ will be the stack for your function,
> not
> the pt_regs. That makes the feature useless.
>
When __irq_svc - or any of the other exception handling assembly code -
calls the C code, the stack pointer will be pointing at the pt_regs
structure.
All the entry points into C code from the exception handling code are
marked with __exception or __exception_irq_enter to indicate that they
are one of the functions which has pt_regs above them.
Normally, when you've entered asm_do_IRQ() you will have this stack
layout (higher address towards top):
pt_regs
asm_do_IRQ frame
If you insert a C function between the exception assembly code and
asm_do_IRQ, you end up with this stack layout instead:
pt_regs
your function frame
asm_do_IRQ frame
This means when we unwind, we'll get to asm_do_IRQ, and rather than
dumping out the pt_regs, we'll dump out your functions stack frame
instead, because that's what is above the asm_do_IRQ stack frame
rather than the expected pt_regs structure.
The fix is to introduce handle_IRQ() for no exception stack dump, so
it can be called with MULTI_IRQ_HANDLER is selected and a C function
is between the assembly code and the actual IRQ handling code.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
2011-07-11 15:25:43 -06:00
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* handle_IRQ handles all hardware IRQ's. Decoded IRQs should
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* not come via this function. Instead, they should provide their
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* own 'handler'. Used by platform code implementing C-based 1st
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* level decoding.
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2005-04-16 16:20:36 -06:00
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*/
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ARM: introduce handle_IRQ() not to dump exception stack
On Mon, Jul 11, 2011 at 3:52 PM, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:
...
> The __exception annotation on a function causes this to happen:
>
> [<c002406c>] (asm_do_IRQ+0x6c/0x8c) from [<c0024b84>]
> (__irq_svc+0x44/0xcc)
> Exception stack(0xc3897c78 to 0xc3897cc0)
> 7c60: 4022d320 4022e000
> 7c80: 08000075 00001000 c32273c0 c03ce1c0 c2b49b78 4022d000 c2b420b4 00000001
> 7ca0: 00000000 c3897cfc 00000000 c3897cc0 c00afc54 c002edd8 00000013 ffffffff
>
> Where that stack dump represents the pt_regs for the exception which
> happened. Any function found in while unwinding will cause this to
> be printed.
>
> If you insert a C function between the IRQ assembly and asm_do_IRQ,
> the
> dump you get from asm_do_IRQ will be the stack for your function,
> not
> the pt_regs. That makes the feature useless.
>
When __irq_svc - or any of the other exception handling assembly code -
calls the C code, the stack pointer will be pointing at the pt_regs
structure.
All the entry points into C code from the exception handling code are
marked with __exception or __exception_irq_enter to indicate that they
are one of the functions which has pt_regs above them.
Normally, when you've entered asm_do_IRQ() you will have this stack
layout (higher address towards top):
pt_regs
asm_do_IRQ frame
If you insert a C function between the exception assembly code and
asm_do_IRQ, you end up with this stack layout instead:
pt_regs
your function frame
asm_do_IRQ frame
This means when we unwind, we'll get to asm_do_IRQ, and rather than
dumping out the pt_regs, we'll dump out your functions stack frame
instead, because that's what is above the asm_do_IRQ stack frame
rather than the expected pt_regs structure.
The fix is to introduce handle_IRQ() for no exception stack dump, so
it can be called with MULTI_IRQ_HANDLER is selected and a C function
is between the assembly code and the actual IRQ handling code.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
2011-07-11 15:25:43 -06:00
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void handle_IRQ(unsigned int irq, struct pt_regs *regs)
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2005-04-16 16:20:36 -06:00
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{
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2006-10-06 14:11:15 -06:00
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struct pt_regs *old_regs = set_irq_regs(regs);
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2008-10-09 06:36:24 -06:00
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irq_enter();
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2005-04-16 16:20:36 -06:00
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/*
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* Some hardware gives randomly wrong interrupts. Rather
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* than crashing, do something sensible.
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*/
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2010-06-25 02:46:09 -06:00
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if (unlikely(irq >= nr_irqs)) {
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2009-06-22 02:23:36 -06:00
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if (printk_ratelimit())
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printk(KERN_WARNING "Bad IRQ%u\n", irq);
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ack_bad_irq(irq);
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} else {
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2008-10-09 06:36:24 -06:00
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generic_handle_irq(irq);
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2009-06-22 02:23:36 -06:00
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}
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2005-04-16 16:20:36 -06:00
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2006-07-01 15:30:09 -06:00
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/* AT91 specific workaround */
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2005-04-16 16:20:36 -06:00
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irq_finish(irq);
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irq_exit();
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2006-10-06 14:11:15 -06:00
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set_irq_regs(old_regs);
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2005-04-16 16:20:36 -06:00
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}
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ARM: introduce handle_IRQ() not to dump exception stack
On Mon, Jul 11, 2011 at 3:52 PM, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:
...
> The __exception annotation on a function causes this to happen:
>
> [<c002406c>] (asm_do_IRQ+0x6c/0x8c) from [<c0024b84>]
> (__irq_svc+0x44/0xcc)
> Exception stack(0xc3897c78 to 0xc3897cc0)
> 7c60: 4022d320 4022e000
> 7c80: 08000075 00001000 c32273c0 c03ce1c0 c2b49b78 4022d000 c2b420b4 00000001
> 7ca0: 00000000 c3897cfc 00000000 c3897cc0 c00afc54 c002edd8 00000013 ffffffff
>
> Where that stack dump represents the pt_regs for the exception which
> happened. Any function found in while unwinding will cause this to
> be printed.
>
> If you insert a C function between the IRQ assembly and asm_do_IRQ,
> the
> dump you get from asm_do_IRQ will be the stack for your function,
> not
> the pt_regs. That makes the feature useless.
>
When __irq_svc - or any of the other exception handling assembly code -
calls the C code, the stack pointer will be pointing at the pt_regs
structure.
All the entry points into C code from the exception handling code are
marked with __exception or __exception_irq_enter to indicate that they
are one of the functions which has pt_regs above them.
Normally, when you've entered asm_do_IRQ() you will have this stack
layout (higher address towards top):
pt_regs
asm_do_IRQ frame
If you insert a C function between the exception assembly code and
asm_do_IRQ, you end up with this stack layout instead:
pt_regs
your function frame
asm_do_IRQ frame
This means when we unwind, we'll get to asm_do_IRQ, and rather than
dumping out the pt_regs, we'll dump out your functions stack frame
instead, because that's what is above the asm_do_IRQ stack frame
rather than the expected pt_regs structure.
The fix is to introduce handle_IRQ() for no exception stack dump, so
it can be called with MULTI_IRQ_HANDLER is selected and a C function
is between the assembly code and the actual IRQ handling code.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
2011-07-11 15:25:43 -06:00
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/*
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* asm_do_IRQ is the interface to be used from assembly code.
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*/
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asmlinkage void __exception_irq_entry
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asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
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{
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handle_IRQ(irq, regs);
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}
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2005-04-16 16:20:36 -06:00
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void set_irq_flags(unsigned int irq, unsigned int iflags)
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{
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2011-02-07 14:30:49 -07:00
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unsigned long clr = 0, set = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
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2005-04-16 16:20:36 -06:00
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2010-06-25 02:46:09 -06:00
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if (irq >= nr_irqs) {
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2005-04-16 16:20:36 -06:00
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printk(KERN_ERR "Trying to set irq flags for IRQ%d\n", irq);
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return;
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}
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2006-07-01 15:30:09 -06:00
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if (iflags & IRQF_VALID)
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2011-02-07 14:30:49 -07:00
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clr |= IRQ_NOREQUEST;
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2006-07-01 15:30:09 -06:00
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if (iflags & IRQF_PROBE)
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2011-02-07 14:30:49 -07:00
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clr |= IRQ_NOPROBE;
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2006-07-01 15:30:09 -06:00
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if (!(iflags & IRQF_NOAUTOEN))
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2011-02-07 14:30:49 -07:00
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clr |= IRQ_NOAUTOEN;
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/* Order is clear bits in "clr" then set bits in "set" */
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irq_modify_status(irq, clr, set & ~clr);
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2005-04-16 16:20:36 -06:00
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}
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void __init init_IRQ(void)
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{
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2010-12-20 03:18:36 -07:00
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machine_desc->init_irq();
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2005-04-16 16:20:36 -06:00
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}
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2010-06-25 02:46:09 -06:00
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#ifdef CONFIG_SPARSE_IRQ
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int __init arch_probe_nr_irqs(void)
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{
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2010-12-20 03:18:36 -07:00
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nr_irqs = machine_desc->nr_irqs ? machine_desc->nr_irqs : NR_IRQS;
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2010-09-27 12:55:03 -06:00
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return nr_irqs;
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2010-06-25 02:46:09 -06:00
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}
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#endif
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2005-11-02 15:24:33 -07:00
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#ifdef CONFIG_HOTPLUG_CPU
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2006-07-11 15:54:34 -06:00
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2011-07-21 08:14:21 -06:00
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static bool migrate_one_irq(struct irq_desc *desc)
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2006-07-11 15:54:34 -06:00
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{
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2011-07-21 08:14:21 -06:00
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struct irq_data *d = irq_desc_get_irq_data(desc);
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2011-07-21 08:07:56 -06:00
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const struct cpumask *affinity = d->affinity;
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2011-07-21 08:14:21 -06:00
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struct irq_chip *c;
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2011-01-23 05:09:36 -07:00
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bool ret = false;
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2006-07-11 15:54:34 -06:00
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2011-07-21 08:14:21 -06:00
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/*
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* If this is a per-CPU interrupt, or the affinity does not
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* include this CPU, then we have nothing to do.
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*/
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if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity))
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return false;
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2011-07-21 08:07:56 -06:00
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if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) {
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2011-07-21 08:14:21 -06:00
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affinity = cpu_online_mask;
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2011-01-23 05:09:36 -07:00
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ret = true;
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}
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2011-07-21 08:14:21 -06:00
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c = irq_data_get_irq_chip(d);
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if (c->irq_set_affinity)
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c->irq_set_affinity(d, affinity, true);
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else
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pr_debug("IRQ%u: unable to set affinity\n", d->irq);
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2011-01-23 05:09:36 -07:00
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return ret;
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2006-07-11 15:54:34 -06:00
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}
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2005-11-02 15:24:33 -07:00
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/*
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2011-07-21 08:14:21 -06:00
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* The current CPU has been marked offline. Migrate IRQs off this CPU.
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* If the affinity settings do not allow other CPUs, force them onto any
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2005-11-02 15:24:33 -07:00
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* available CPU.
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2011-07-21 08:14:21 -06:00
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*
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* Note: we must iterate over all IRQs, whether they have an attached
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* action structure or not, as we need to get chained interrupts too.
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2005-11-02 15:24:33 -07:00
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*/
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void migrate_irqs(void)
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{
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2011-07-21 08:14:21 -06:00
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unsigned int i;
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2010-06-25 02:46:09 -06:00
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struct irq_desc *desc;
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2011-01-23 05:09:36 -07:00
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unsigned long flags;
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local_irq_save(flags);
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2005-11-02 15:24:33 -07:00
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2010-06-25 02:46:09 -06:00
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for_each_irq_desc(i, desc) {
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2011-01-23 05:09:36 -07:00
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bool affinity_broken = false;
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2010-11-29 02:21:48 -07:00
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2011-07-21 08:14:21 -06:00
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if (!desc)
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continue;
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2011-01-23 05:09:36 -07:00
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raw_spin_lock(&desc->lock);
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2011-07-21 08:14:21 -06:00
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affinity_broken = migrate_one_irq(desc);
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2011-01-23 05:09:36 -07:00
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raw_spin_unlock(&desc->lock);
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if (affinity_broken && printk_ratelimit())
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2011-07-21 08:14:21 -06:00
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pr_warning("IRQ%u no longer affine to CPU%u\n", i,
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smp_processor_id());
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2005-11-02 15:24:33 -07:00
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}
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2011-01-23 05:09:36 -07:00
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local_irq_restore(flags);
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2005-11-02 15:24:33 -07:00
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}
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#endif /* CONFIG_HOTPLUG_CPU */
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