kernel/arch/mips/include/asm/irq.h, branch linux-rolling-stable

nmi_backtrace: allow excluding an arbitrary CPU

2023-09-13T07:53:08Z

[ Upstream commit 8d539b84f1e3478436f978ceaf55a0b6cab497b5 ] The APIs that allow backtracing across CPUs have always had a way to exclude the current CPU. This convenience means callers didn't need to find a place to allocate a CPU mask just to handle the common case. Let's extend the API to take a CPU ID to exclude instead of just a boolean. This isn't any more complex for the API to handle and allows the hardlockup detector to exclude a different CPU (the one it already did a trace for) without needing to find space for a CPU mask. Arguably, this new API also encourages safer behavior. Specifically if the caller wants to avoid tracing the current CPU (maybe because they already traced the current CPU) this makes it more obvious to the caller that they need to make sure that the current CPU ID can't change. [akpm@linux-foundation.org: fix trigger_allbutcpu_cpu_backtrace() stub] Link: https://lkml.kernel.org/r/20230804065935.v4.1.Ia35521b91fc781368945161d7b28538f9996c182@changeid Signed-off-by: Douglas Anderson Acked-by: Michal Hocko Cc: kernel test robot Cc: Lecopzer Chen Cc: Petr Mladek Cc: Pingfan Liu Signed-off-by: Andrew Morton Stable-dep-of: 1f38c86bb29f ("watchdog/hardlockup: avoid large stack frames in watchdog_hardlockup_check()") Signed-off-by: Sasha Levin

init: consolidate prototypes in linux/init.h

2023-06-10T00:44:16Z

The init/main.c file contains some extern declarations for functions defined in architecture code, and it defines some other functions that are called from architecture code with a custom prototype. Both of those result in warnings with 'make W=1': init/calibrate.c:261:37: error: no previous prototype for 'calibrate_delay_is_known' [-Werror=missing-prototypes] init/main.c:790:20: error: no previous prototype for 'mem_encrypt_init' [-Werror=missing-prototypes] init/main.c:792:20: error: no previous prototype for 'poking_init' [-Werror=missing-prototypes] arch/arm64/kernel/irq.c:122:13: error: no previous prototype for 'init_IRQ' [-Werror=missing-prototypes] arch/arm64/kernel/time.c:55:13: error: no previous prototype for 'time_init' [-Werror=missing-prototypes] arch/x86/kernel/process.c:935:13: error: no previous prototype for 'arch_post_acpi_subsys_init' [-Werror=missing-prototypes] init/calibrate.c:261:37: error: no previous prototype for 'calibrate_delay_is_known' [-Werror=missing-prototypes] kernel/fork.c:991:20: error: no previous prototype for 'arch_task_cache_init' [-Werror=missing-prototypes] Add prototypes for all of these in include/linux/init.h or another appropriate header, and remove the duplicate declarations from architecture specific code. [sfr@canb.auug.org.au: declare time_init_early()] Link: https://lkml.kernel.org/r/20230519124311.5167221c@canb.auug.org.au Link: https://lkml.kernel.org/r/20230517131102.934196-12-arnd@kernel.org Signed-off-by: Arnd Bergmann Signed-off-by: Stephen Rothwell Cc: Boqun Feng Cc: Catalin Marinas Cc: Christoph Lameter Cc: Dennis Zhou Cc: Eric Paris Cc: Heiko Carstens Cc: Helge Deller Cc: Ingo Molnar Cc: Michael Ellerman Cc: Michal Simek Cc: Palmer Dabbelt Cc: Paul Moore Cc: Pavel Machek Cc: Peter Zijlstra Cc: Rafael J. Wysocki Cc: Russell King Cc: Tejun Heo Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Waiman Long Cc: Will Deacon Signed-off-by: Andrew Morton

MIPS: IRQ: remove orphan allocate_irqno() declaration

2022-09-24T09:47:18Z

All uses of allocate_irqno() have been removed by commit 69a07a41d908 ("MIPS: SGI-IP27: rework HUB interrupts"), so remove the orphan declaration. Signed-off-by: Gaosheng Cui Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Thomas Bogendoerfer

MIPS: IRQ: remove orphan declarations from arch/mips/include/asm/irq.h

2022-09-19T14:36:29Z

All uses of free_irqno() and alloc_legacy_irqno() were removed by commit 69a07a41d908 ("MIPS: SGI-IP27: rework HUB interrupts"), so remove the orphan declarations, too. Signed-off-by: Gaosheng Cui Signed-off-by: Thomas Bogendoerfer

irqchip/mips: Fix RCU violation when using irqdomain lookup on interrupt entry

2021-07-09T09:18:58Z

Since d4a45c68dc81 ("irqdomain: Protect the linear revmap with RCU"), any irqdomain lookup requires the RCU read lock to be held. This assumes that the architecture code will be structured such as irq_enter() will be called *before* the interrupt is looked up in the irq domain. However, this isn't the case for MIPS, and a number of drivers are structured to do it the other way around when handling an interrupt in their root irqchip (secondary irqchips are OK by construction). This results in a RCU splat on a lockdep-enabled kernel when the kernel takes an interrupt from idle, as reported by Guenter Roeck. Note that this could have fired previously if any driver had used tree-based irqdomain, which always had the RCU requirement. To solve this, provide a MIPS-specific helper (do_domain_IRQ()) as the pendent of do_IRQ() that will do thing in the right order (and maybe save some cycles in the process). Ideally, MIPS would be moved over to using handle_domain_irq(), but that's much more ambitious. Reported-by: Guenter Roeck Tested-by: Guenter Roeck [maz: add dependency on CONFIG_IRQ_DOMAIN after report from the kernelci bot] Signed-off-by: Marc Zyngier Cc: Thomas Bogendoerfer Cc: Serge Semin Link: https://lore.kernel.org/r/20210705172352.GA56304@roeck-us.net Link: https://lore.kernel.org/r/20210706110647.3979002-1-maz@kernel.org

MIPS: Do not include linux/irqdomain.h from asm/irq.h

2021-06-10T12:09:16Z

Including linux/irqdomain.h from asm/irq.h is going to break as soon as linux/irqdomain.h will include linux/irq.h, so let's fix this. Code relying on linux/irqomain.h should include it directly. Signed-off-by: Marc Zyngier

MIPS: IRQ: Add prototype for function init_IRQ

2021-01-19T22:04:32Z

This commit adds a prototype to fix error at W=1: arch/mips/kernel/irq.c:52:13: error: no previous prototype for 'init_IRQ' [-Werror=missing-prototypes] Signed-off-by: Yanteng Si Reviewed-by: Huacai Chen Signed-off-by: Thomas Bogendoerfer

MIPS: Fix minimum alignment requirement of IRQ stack

2017-07-11T12:13:06Z

Commit db8466c581cc ("MIPS: IRQ Stack: Unwind IRQ stack onto task stack") erroneously set the initial stack pointer of the IRQ stack to a value with a 4 byte alignment. The MIPS32 ABI requires that the minimum stack alignment is 8 byte, and the MIPS64 ABIs(n32/n64) require 16 byte minimum alignment. Fix IRQ_STACK_START such that it leaves space for the dummy stack frame (containing interrupted task kernel stack pointer) while also meeting minimum alignment requirements. Fixes: db8466c581cc ("MIPS: IRQ Stack: Unwind IRQ stack onto task stack") Reported-by: Darius Ivanauskas Signed-off-by: Matt Redfearn Cc: Chris Metcalf Cc: Petr Mladek Cc: Aaron Tomlin Cc: Jason A. Donenfeld Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16760/ Signed-off-by: Ralf Baechle

MIPS: IRQ Stack: Unwind IRQ stack onto task stack

2017-03-22T10:53:57Z

When the separate IRQ stack was introduced, stack unwinding only proceeded as far as the top of the IRQ stack, leading to kernel backtraces being less useful, lacking the trace of what was interrupted. Fix this by providing a means for the kernel to unwind the IRQ stack onto the interrupted task stack. The processor state is saved to the kernel task stack on interrupt. The IRQ_STACK_START macro reserves an unsigned long at the top of the IRQ stack where the interrupted task stack pointer can be saved. After the active stack is switched to the IRQ stack, save the interrupted tasks stack pointer to the reserved location. Fix the stack unwinding code to look for the frame being the top of the IRQ stack and if so get the next frame from the saved location. The existing test does not work with the separate stack since the ra is no longer pointed at ret_from_{irq,exception}. The test to stop unwinding the stack 32 bytes from the top of a stack must be modified to allow unwinding to continue up to the location of the saved task stack pointer when on the IRQ stack. The low / high marks of the stack are set depending on whether the sp is on an irq stack or not. Signed-off-by: Matt Redfearn Cc: Paolo Bonzini Cc: Marcin Nowakowski Cc: Masanari Iida Cc: Chris Metcalf Cc: James Hogan Cc: Paul Burton Cc: Ingo Molnar Cc: Jason A. Donenfeld Cc: Andrew Morton Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/15788/ Signed-off-by: Ralf Baechle

MIPS: Introduce irq_stack

2017-01-03T15:34:34Z

Allocate a per-cpu irq stack for use within interrupt handlers. Also add a utility function on_irq_stack to determine if a given stack pointer is within the irq stack for that cpu. Signed-off-by: Matt Redfearn Acked-by: Jason A. Donenfeld Cc: Thomas Gleixner Cc: Paolo Bonzini Cc: Chris Metcalf Cc: Petr Mladek Cc: James Hogan Cc: Paul Burton Cc: Aaron Tomlin Cc: Andrew Morton Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14740/ Signed-off-by: Ralf Baechle