Commit 22aaec35 authored by Jisheng Zhang's avatar Jisheng Zhang Committed by Peter Zijlstra
Browse files

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 ]

Signed-off-by: default avatarJisheng Zhang <jszhang@kernel.org>
Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
Link: https://lkml.kernel.org/r/20241021151257.102296-4-bigeasy@linutronix.de
parent 476e8583

arch/riscv/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ 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

arch/riscv/include/asm/thread_info.h

+6 −4
Original line number Diff line number Diff line
@@ -107,9 +107,10 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); 
 * - 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 */
@@ -117,9 +118,10 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); 
#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)