This adds the asm macro definition 'b_if_no_resched' that performs a conditional branch depending on the preempt need_resched state. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> --- arch/arm64/include/asm/assembler.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index fd3e3924041b..296105fd3021 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -22,6 +22,11 @@ #include <asm/ptrace.h> +#if defined(CONFIG_PREEMPT) || defined(CONFIG_PREEMPT_VOLUNTARY) +#include <asm/asm-offsets.h> +#include <asm/thread_info.h> +#endif + /* * Stack pushing/popping (register pairs only). Equivalent to store decrement * before, load increment after. @@ -146,3 +151,19 @@ lr .req x30 // link register #endif orr \rd, \lbits, \hbits, lsl #32 .endm + +/* + * 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 /* need rescheduling? */ +#else + b \lb +#endif + .endm -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
