[PATCH RFC 1/3] arm64/crypto: add shared macro to test for NEED_RESCHED
From: Nicolas Pitre <hidden>
Date: 2014-03-29 01:53:23
On Fri, 28 Mar 2014, Ard Biesheuvel wrote:
This adds arch/arm64/crypto/preempt.h, currently containing just a single asm macro definition 'b_if_no_resched' that will be shared between multiple crypto algorithm implementations that need to test for preemption in the inner loop.
This file is a rather bad choice for this pretty generic macro. There is nothing crypto specific about it, even if crypto might be the only user for now. This should live in include/asm/assembler.h, or a separate file in that directory only if including <asm/asm-offsets.h> from assembler.h is considered a nuisance.
quoted hunk ↗ jump to hunk
Signed-off-by: Ard Biesheuvel <redacted> --- arch/arm64/crypto/preempt.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) create mode 100644 arch/arm64/crypto/preempt.hdiff --git a/arch/arm64/crypto/preempt.h b/arch/arm64/crypto/preempt.h new file mode 100644 index 000000000000..94302d5b5ae9 --- /dev/null +++ b/arch/arm64/crypto/preempt.h@@ -0,0 +1,28 @@ +/* + * preempt.h - shared macros to check preempt state + * + * Copyright (C) 2014 Linaro Ltd <ard.biesheuvel@linaro.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <asm/asm-offsets.h> +#include <asm/thread_info.h> + + /* + * Branch to 'lb' but only if we have not been tagged for preemption. + * + * Expects current->thread_info in ti, or NULL if running in interrupt + * context. reg is a scratch x register. + */ + .macro b_if_no_resched, ti, reg, lb +#if defined(CONFIG_PREEMPT) || defined(CONFIG_PREEMPT_VOLUNTARY) + cbz \ti, \lb // have thread_info? + ldr \reg, [\ti, #TI_FLAGS] // get flags + tbz \reg, #TIF_NEED_RESCHED, \lb // needs rescheduling? +#else + b \lb +#endif + .endm-- 1.8.3.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel at lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel