kernel.git/arch/arm/include/asm/irq.h, branch linux-3.2.y

ARM: introduce handle_IRQ() not to dump exception stack

2011-07-12T11:42:40Z

On Mon, Jul 11, 2011 at 3:52 PM, Russell King - ARM Linux wrote: ... > The __exception annotation on a function causes this to happen: > > [] (asm_do_IRQ+0x6c/0x8c) from [] > (__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 Signed-off-by: Eric Miao

ARM: 6197/2: preliminary support for sparse IRQ

2010-07-09T13:41:33Z

So to allow NR_IRQS to be dynamic and platforms to specify the number of IRQs really needed. Acked-by: Paul Mundt Signed-off-by: Eric Miao Signed-off-by: Russell King

ARM: 6000/1: removing compilation warning comming from

2010-03-29T16:33:31Z

irq.h is using struct pt_regs *. Due to this compilation warning is comming. Removing this warning by adding declaration of struct pt_regs. Signed-off-by: Viresh Kumar Signed-off-by: Russell King

[ARM] give RiscPC a NR_IRQS definition and remove default

2008-11-29T19:14:31Z

RiscPC is the only platform using the default setting for NR_IRQS, so the default NR_IRQS doesn't really make sense; remove it and make RiscPC provide such a definition. Signed-off-by: Russell King

[ARM] sparse: quieten arch/arm/kernel/irq.c

2008-09-06T09:56:27Z

Signed-off-by: Russell King

[ARM] Move include/asm-arm/arch-* to arch/arm/*/include/mach

2008-08-07T08:55:48Z

This just leaves include/asm-arm/plat-* to deal with. Signed-off-by: Russell King

[ARM] move include/asm-arm to arch/arm/include/asm

2008-08-02T20:32:35Z

Move platform independent header files to arch/arm/include/asm, leaving those in asm/arch* and asm/plat* alone. Signed-off-by: Russell King