arch/riscv/include/asm/thread_info.h

Source file repositories/reference/linux-study-clean/arch/riscv/include/asm/thread_info.h

File Facts

System
Linux kernel
Corpus path
arch/riscv/include/asm/thread_info.h
Extension
.h
Size
3524 bytes
Lines
128
Domain
Architecture Layer
Bucket
arch/riscv
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

struct thread_info {
	unsigned long		flags;		/* low level flags */
	int                     preempt_count;  /* 0=>preemptible, <0=>BUG */
	/*
	 * These stack pointers are overwritten on every system call or
	 * exception.  SP is also saved to the stack it can be recovered when
	 * overwritten.
	 */
	long			kernel_sp;	/* Kernel stack pointer */
	long			user_sp;	/* User stack pointer */
	int			cpu;
	unsigned long		syscall_work;	/* SYSCALL_WORK_ flags */
#ifdef CONFIG_SHADOW_CALL_STACK
	void			*scs_base;
	void			*scs_sp;
#endif
#ifdef CONFIG_64BIT
	/*
	 * Used in handle_exception() to save a0, a1 and a2 before knowing if we
	 * can access the kernel stack.
	 */
	unsigned long		a0, a1, a2;
#endif
#ifdef CONFIG_RISCV_USER_CFI
	struct cfi_state	user_cfi_state;
#endif
};

#ifdef CONFIG_SHADOW_CALL_STACK
#define INIT_SCS							\
	.scs_base	= init_shadow_call_stack,			\
	.scs_sp		= init_shadow_call_stack,
#else
#define INIT_SCS
#endif

/*
 * macros/functions for gaining access to the thread information structure
 *
 * preempt_count needs to be 1 initially, until the scheduler is functional.
 */
#define INIT_THREAD_INFO(tsk)			\
{						\
	.flags		= 0,			\
	.preempt_count	= INIT_PREEMPT_COUNT,	\
	INIT_SCS				\
}

void arch_release_task_struct(struct task_struct *tsk);
int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);

#endif /* !__ASSEMBLER__ */

/*
 * thread information flags
 * - these are process state flags that various assembly files may need to
 *   access
 * - pending work-to-be-done flags are in lowest half-word
 * - other flags in upper half-word(s)
 */

/*
 * Tell the generic TIF infrastructure which bits riscv supports
 */
#define HAVE_TIF_NEED_RESCHED_LAZY
#define HAVE_TIF_RESTORE_SIGMASK

#include <asm-generic/thread_info_tif.h>

#define TIF_32BIT			16	/* compat-mode 32bit process */
#define TIF_RISCV_V_DEFER_RESTORE	17	/* restore Vector before returning to user */

#define _TIF_RISCV_V_DEFER_RESTORE	BIT(TIF_RISCV_V_DEFER_RESTORE)

#endif /* _ASM_RISCV_THREAD_INFO_H */

Annotation

Implementation Notes