9c0e6a89b5
Pull ARM updates from Russell King:
"Updates for IRQ stacks and virtually mapped stack support, and ftrace:
- Support for IRQ and vmap'ed stacks
This covers all the work related to implementing IRQ stacks and
vmap'ed stacks for all 32-bit ARM systems that are currently
supported by the Linux kernel, including RiscPC and Footbridge. It
has been submitted for review in four different waves:
- IRQ stacks support for v7 SMP systems [0]
- vmap'ed stacks support for v7 SMP systems[1]
- extending support for both IRQ stacks and vmap'ed stacks for all
remaining configurations, including v6/v7 SMP multiplatform
kernels and uniprocessor configurations including v7-M [2]
- fixes and updates in [3]
- ftrace fixes and cleanups
Make all flavors of ftrace available on all builds, regardless of
ISA choice, unwinder choice or compiler [4]:
- use ADD not POP where possible
- fix a couple of Thumb2 related issues
- enable HAVE_FUNCTION_GRAPH_FP_TEST for robustness
- enable the graph tracer with the EABI unwinder
- avoid clobbering frame pointer registers to make Clang happy
- Fixes for the above"
[0] https://lore.kernel.org/linux-arm-kernel/20211115084732.3704393-1-ardb@kernel.org/
[1] https://lore.kernel.org/linux-arm-kernel/20211122092816.2865873-1-ardb@kernel.org/
[2] https://lore.kernel.org/linux-arm-kernel/20211206164659.1495084-1-ardb@kernel.org/
[3] https://lore.kernel.org/linux-arm-kernel/20220124174744.1054712-1-ardb@kernel.org/
[4] https://lore.kernel.org/linux-arm-kernel/20220203082204.1176734-1-ardb@kernel.org/
* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (62 commits)
ARM: fix building NOMMU ARMv4/v5 kernels
ARM: unwind: only permit stack switch when unwinding call_with_stack()
ARM: Revert "unwind: dump exception stack from calling frame"
ARM: entry: fix unwinder problems caused by IRQ stacks
ARM: unwind: set frame.pc correctly for current-thread unwinding
ARM: 9184/1: return_address: disable again for CONFIG_ARM_UNWIND=y
ARM: 9183/1: unwind: avoid spurious warnings on bogus code addresses
Revert "ARM: 9144/1: forbid ftrace with clang and thumb2_kernel"
ARM: mach-bcm: disable ftrace in SMC invocation routines
ARM: cacheflush: avoid clobbering the frame pointer
ARM: kprobes: treat R7 as the frame pointer register in Thumb2 builds
ARM: ftrace: enable the graph tracer with the EABI unwinder
ARM: unwind: track location of LR value in stack frame
ARM: ftrace: enable HAVE_FUNCTION_GRAPH_FP_TEST
ARM: ftrace: avoid unnecessary literal loads
ARM: ftrace: avoid redundant loads or clobbering IP
ARM: ftrace: use trampolines to keep .init.text in branching range
ARM: ftrace: use ADD not POP to counter PUSH at entry
ARM: ftrace: ensure that ADR takes the Thumb bit into account
ARM: make get_current() and __my_cpu_offset() __always_inline
...
36 lines
1.2 KiB
C
36 lines
1.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __ASM_ARM_SWITCH_TO_H
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#define __ASM_ARM_SWITCH_TO_H
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#include <linux/thread_info.h>
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#include <asm/smp_plat.h>
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/*
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* For v7 SMP cores running a preemptible kernel we may be pre-empted
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* during a TLB maintenance operation, so execute an inner-shareable dsb
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* to ensure that the maintenance completes in case we migrate to another
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* CPU.
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*/
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#if defined(CONFIG_PREEMPTION) && defined(CONFIG_SMP) && defined(CONFIG_CPU_V7)
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#define __complete_pending_tlbi() dsb(ish)
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#else
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#define __complete_pending_tlbi()
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#endif
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/*
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* switch_to(prev, next) should switch from task `prev' to `next'
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* `prev' will never be the same as `next'. schedule() itself
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* contains the memory barrier to tell GCC not to cache `current'.
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*/
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extern struct task_struct *__switch_to(struct task_struct *, struct thread_info *, struct thread_info *);
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#define switch_to(prev,next,last) \
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do { \
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__complete_pending_tlbi(); \
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if (IS_ENABLED(CONFIG_CURRENT_POINTER_IN_TPIDRURO) || is_smp()) \
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__this_cpu_write(__entry_task, next); \
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last = __switch_to(prev,task_thread_info(prev), task_thread_info(next)); \
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} while (0)
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#endif /* __ASM_ARM_SWITCH_TO_H */
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