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2020-07-10arm: Break cyclic percpu includePeter Zijlstra1-0/+2
In order to use <asm/percpu.h> in irqflags.h, we need to make sure asm/percpu.h does not itself depend on irqflags.h. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lkml.kernel.org/r/20200623083721.454517573@infradead.org
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201Thomas Gleixner1-12/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms and conditions of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 228 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528171438.107155473@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-13ARM: 8174/1: Use global stack register variable for percpuMark Charlebois1-2/+2
Using global current_stack_pointer works on both clang and gcc. current_stack_pointer is an unsigned long and needs to be cast as a pointer to dereference. Signed-off-by: Mark Charlebois <charlebm@gmail.com> Signed-off-by: Behan Webster <behanw@converseincode.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-06-05ARM: 7747/1: pcpu: ensure __my_cpu_offset cannot be re-ordered across barrier()Will Deacon1-2/+9
__my_cpu_offset is non-volatile, since we want its value to be cached when we access several per-cpu variables in a row with preemption disabled. This means that we rely on preempt_{en,dis}able to hazard with the operation via the barrier() macro, so that we can't end up migrating CPUs without reloading the per-cpu offset. Unfortunately, GCC doesn't treat a "memory" clobber on a non-volatile asm block as a side-effect, and will happily re-order it before other memory clobbers (including those in prempt_disable()) and cache the value. This has been observed to break the cmpxchg logic in the slub allocator, leading to livelock in kmem_cache_alloc in mainline kernels. This patch adds a dummy memory input operand to __my_cpu_offset, forcing it to be ordered with respect to the barrier() macro. Cc: <stable@vger.kernel.org> Cc: Rob Herring <rob.herring@calxeda.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-12-03ARM: 7587/1: implement optimized percpu variable accessRob Herring1-0/+45
Use the previously unused TPIDRPRW register to store percpu offsets. TPIDRPRW is only accessible in PL1, so it can only be used in the kernel. This replaces 2 loads with a mrc instruction for each percpu variable access. With hackbench, the performance improvement is 1.4% on Cortex-A9 (highbank). Taking an average of 30 runs of "hackbench -l 1000" yields: Before: 6.2191 After: 6.1348 Will Deacon reported similar delta on v6 with 11MPCore. The asm "memory clobber" are needed here to ensure the percpu offset gets reloaded. Testing by Will found that this would not happen in __schedule() which is a bit of a special case as preemption is disabled but the execution can move cores. Signed-off-by: Rob Herring <rob.herring@calxeda.com> Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-10-17ARM: 7006/1: Migrate to asm-generic wrapper supportStephen Boyd1-6/+0
With d8ecc5c (kbuild: asm-generic support, 2011-04-27) we can remove a handful of asm-generic wrappers in ARM code. Since the generic version of sizes.h doesn't contain SZ_48M, we replace the 4 users of SZ_48M with the equivalent SZ_32M + SZ_16M. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Imre Kaloz <kaloz@openwrt.org> Acked-by: Krzysztof Halasa <khc@pm.waw.pl> Cc: Eric Miao <eric.y.miao@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-08-02[ARM] move include/asm-arm to arch/arm/include/asmRussell King1-0/+6
Move platform independent header files to arch/arm/include/asm, leaving those in asm/arch* and asm/plat* alone. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>