From: Jisheng Zhang <jszhang@kernel.org> Date: Wed, 9 Oct 2024 11:35:19 +0200 Subject: [PATCH 3/3] riscv: add PREEMPT_LAZY support riscv has switched to GENERIC_ENTRY, so adding PREEMPT_LAZY is as simple as adding TIF_NEED_RESCHED_LAZY related definitions and enabling ARCH_HAS_PREEMPT_LAZY. [bigeasy: Replace old PREEMPT_AUTO bits with new PREEMPT_LAZY ] Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: linux-riscv@lists.infradead.org Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> --- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/thread_info.h | 10 ++++++---- 2 files changed, 7 insertions(+), 4 deletions(-) @ arch/riscv/Kconfig:42 @ config RISCV select ARCH_HAS_MMIOWB select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE select ARCH_HAS_PMEM_API + select ARCH_HAS_PREEMPT_LAZY select ARCH_HAS_PREPARE_SYNC_CORE_CMD select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU select ARCH_HAS_PTE_SPECIAL --- a/arch/riscv/include/asm/thread_info.h +++ b/arch/riscv/include/asm/thread_info.h @ arch/riscv/Kconfig:110 @ 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_NOTIFY_RESUME 1 /* callback before returning to user */ -#define TIF_SIGPENDING 2 /* signal pending */ -#define TIF_NEED_RESCHED 3 /* rescheduling necessary */ +#define TIF_NEED_RESCHED 0 /* rescheduling necessary */ +#define TIF_NEED_RESCHED_LAZY 1 /* Lazy rescheduling needed */ +#define TIF_NOTIFY_RESUME 2 /* callback before returning to user */ +#define TIF_SIGPENDING 3 /* signal pending */ #define TIF_RESTORE_SIGMASK 4 /* restore signal mask in do_signal() */ #define TIF_MEMDIE 5 /* is terminating due to OOM killer */ #define TIF_NOTIFY_SIGNAL 9 /* signal notifications exist */ @ arch/riscv/Kconfig:121 @ 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_NEED_RESCHED (1 << TIF_NEED_RESCHED) +#define _TIF_NEED_RESCHED_LAZY (1 << TIF_NEED_RESCHED_LAZY) #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) -#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) #define _TIF_NOTIFY_SIGNAL (1 << TIF_NOTIFY_SIGNAL) #define _TIF_UPROBE (1 << TIF_UPROBE) #define _TIF_RISCV_V_DEFER_RESTORE (1 << TIF_RISCV_V_DEFER_RESTORE)