lwn.git/arch/m68k/kernel/ints.c, branch v6.9-rc4

m68k: kernel: Add and use "ints.h"

2023-10-06T08:03:01+00:00

When building with W=1: arch/m68k/kernel/ints.c:165:17: warning: no previous prototype for ‘handle_badint’ [-Wmissing-prototypes] 165 | asmlinkage void handle_badint(struct pt_regs *regs) | ^~~~~~~~~~~~~ Fix this by introducing a new header file "ints.h" for holding the prototypes of functions implemented in arch/m68k/kernel/ints.c. Signed-off-by: Geert Uytterhoeven Acked-by: Arnd Bergmann Link: https://lore.kernel.org/r/dc65d01ca4c7de94ce814e5b5e1f726fff97566b.1694613528.git.geert@linux-m68k.org

m68k: Do not rely on magic indirect includes

2014-03-05T12:28:32+00:00

commit: 8f945a33 (genirq: Move kstat_incr_irqs_this_cpu() to core) unearthed the following: arch/m68k/kernel/ints.c:34:15: error: variable 'auto_irq_chip' has initializer but incomplete type arch/m68k/kernel/ints.c:35:2: error: unknown field 'name' specified in initializer arch/m68k/kernel/ints.c:35:2: warning: excess elements in struct initializer [enabled by default] The reason is that this file requires linux/irq.h and magically pulled that in via linux/kernel_stat.h The commit above got rid of the pointless include of linux/irq.h in linux/kernel_stat.h and therefor broke the build. Include linux/irq.h Reported-by: fengguang.wu@intel.com Signed-off-by: Thomas Gleixner

m68k: Simplify low level interrupt handling code

2013-11-13T19:21:46+00:00

The low level interrupt entry code of m68k contains the following: add_preempt_count(HARDIRQ_OFFSET); do_IRQ(); irq_enter(); add_preempt_count(HARDIRQ_OFFSET); handle_interrupt(); irq_exit(); sub_preempt_count(HARDIRQ_OFFSET); if (in_interrupt()) return; <---- On m68k always taken! if (local_softirq_pending()) do_softirq(); sub_preempt_count(HARDIRQ_OFFSET); if (in_hardirq()) return; if (status_on_stack_has_interrupt_priority_mask > 0) return; if (local_softirq_pending()) do_softirq(); ret_from_exception: if (interrupted_context_is_kernel) return: .... I tried to find a proper explanation for this, but the changelog is sparse and there are no mails explaining it further. But obviously this relates to the interrupt priority levels of the m68k and tries to be extra clever with nested interrupts. Though this cleverness just adds code bloat to the interrupt hotpath. For the common case of non nested interrupts the code runs through two extra conditionals to the only important one, which checks whether the return is to kernel or user space. For the nested case the checks for in_hardirq() and the priority mask value on stack catch only the case where the nested interrupt happens inside the hard irq context of the first interrupt. If the nested interrupt happens while the first interrupt handles soft interrupts, then these extra checks buy nothing. The nested interrupt will fall through to the final kernel/user space return check at ret_from_exception. Changing the code flow in the following way: do_IRQ(); irq_enter(); add_preempt_count(HARDIRQ_OFFSET); handle_interrupt(); irq_exit(); sub_preempt_count(HARDIRQ_OFFSET); if (in_interrupt()) return; if (local_softirq_pending()) do_softirq(); ret_from_exception: if (interrupted_context_is_kernel) return: makes the region protected by the hardirq count slightly smaller and the softirq handling is invoked with a minimal deeper stack. But otherwise it's completely functional equivalent and saves 104 bytes of text in arch/m68k/kernel/entry.o. This modification allows us further to get rid of the limitations which m68k puts on the preempt_count layout, so we can make the preempt count bits completely generic. Signed-off-by: Thomas Gleixner Tested-by: Michael Schmitz Acked-by: Geert Uytterhoeven Cc: Linux/m68k Cc: Andreas Schwab Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1311112052360.30673@ionos.tec.linutronix.de

m68k/irq: Vector ints need a valid interrupt handler

2013-06-24T17:44:19+00:00

To get vectored interrupts working we need to switch from the default handler handle_bad_irq() to something more sensible. Tested on a MVME177 board. Signed-off-by: Thomas Bogendoerfer Signed-off-by: Geert Uytterhoeven

Disintegrate asm/system.h for M68K

2012-03-28T17:30:02+00:00

Disintegrate asm/system.h for M68K. Signed-off-by: David Howells Acked-by: Greg Ungerer cc: linux-m68k@lists.linux-m68k.org

m68k/irq: Remove obsolete support for user vector interrupt fixups

2011-11-08T21:35:52+00:00

It was used on Apollo only, before its conversion to genirq. Signed-off-by: Geert Uytterhoeven

m68k/irq: Remove obsolete m68k irq framework

2011-11-08T21:35:52+00:00

Signed-off-by: Geert Uytterhoeven

m68k/irq: Add genirq support

2011-11-08T21:35:49+00:00

Disabled on all platforms for now Signed-off-by: Geert Uytterhoeven [v1] Acked-by: Thomas Gleixner

m68k/irq: Remove obsolete IRQ_FLG_* users

2011-11-08T21:35:48+00:00

The m68k core irq code stopped honoring these flags during the irq restructuring in 2006. Signed-off-by: Geert Uytterhoeven

m68k/irq: Rename {,__}m68k_handle_int()

2011-11-08T21:35:48+00:00

- Rename m68k_handle_int() to generic_handle_irq(), and drop the unneeded asmlinkage, - Rename __m68k_handle_int() to do_IRQ(). Signed-off-by: Geert Uytterhoeven