From: Jisheng Zhang Date: Tue, 31 Oct 2023 22:35:20 +0800 Subject: [PATCH] riscv: add PREEMPT_AUTO support Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.8/older/patches-6.8.2-rt11.tar.xz riscv has switched to GENERIC_ENTRY, so adding PREEMPT_AUTO is as simple as adding TIF_ARCH_RESCHED_LAZY related definitions and enabling HAVE_PREEMPT_AUTO. Signed-off-by: Jisheng Zhang Signed-off-by: Sebastian Andrzej Siewior --- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/thread_info.h | 2 ++ 2 files changed, 3 insertions(+) --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -142,6 +142,7 @@ config RISCV select HAVE_PERF_USER_STACK_DUMP select HAVE_POSIX_CPU_TIMERS_TASK_WORK select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL + select HAVE_PREEMPT_AUTO select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_RETHOOK if !XIP_KERNEL select HAVE_RSEQ --- a/arch/riscv/include/asm/thread_info.h +++ b/arch/riscv/include/asm/thread_info.h @@ -94,6 +94,7 @@ int arch_dup_task_struct(struct task_str * - pending work-to-be-done flags are in lowest half-word * - other flags in upper half-word(s) */ +#define TIF_ARCH_RESCHED_LAZY 0 /* Lazy rescheduling */ #define TIF_NOTIFY_RESUME 1 /* callback before returning to user */ #define TIF_SIGPENDING 2 /* signal pending */ #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ @@ -104,6 +105,7 @@ int arch_dup_task_struct(struct task_str #define TIF_32BIT 11 /* compat-mode 32bit process */ #define TIF_RISCV_V_DEFER_RESTORE 12 /* restore Vector before returing to user */ +#define _TIF_ARCH_RESCHED_LAZY (1 << TIF_ARCH_RESCHED_LAZY) #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)