arch/mips/kernel/scall64-n64.S

Source file repositories/reference/linux-study-clean/arch/mips/kernel/scall64-n64.S

File Facts

System
Linux kernel
Corpus path
arch/mips/kernel/scall64-n64.S
Extension
.S
Size
2795 bytes
Lines
117
Domain
Architecture Layer
Bucket
arch/mips
Inferred role
Architecture Layer: arch/mips
Status
atlas-only

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

#include <linux/errno.h>
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/irqflags.h>
#include <asm/mipsregs.h>
#include <asm/regdef.h>
#include <asm/stackframe.h>
#include <asm/asm-offsets.h>
#include <asm/sysmips.h>
#include <asm/thread_info.h>
#include <asm/unistd.h>

#ifndef CONFIG_MIPS32_COMPAT
/* Neither O32 nor N32, so define handle_sys here */
#define handle_sys64 handle_sys
#endif

	.align	5
NESTED(handle_sys64, PT_SIZE, sp)
#if !defined(CONFIG_MIPS32_O32) && !defined(CONFIG_MIPS32_N32)
	/*
	 * When 32-bit compatibility is configured scall_o32.S
	 * already did this.
	 */
	.set	noat
	SAVE_SOME
	TRACE_IRQS_ON_RELOAD
	STI
	.set	at
#endif

#if !defined(CONFIG_MIPS32_O32) && !defined(CONFIG_MIPS32_N32)
	ld	t1, PT_EPC(sp)		# skip syscall on return
	daddiu	t1, 4			# skip to next instruction
	sd	t1, PT_EPC(sp)
#endif

	sd	a3, PT_R26(sp)		# save a3 for syscall restarting

	LONG_S	v0, TI_SYSCALL($28)     # Store syscall number

	li	t1, _TIF_WORK_SYSCALL_ENTRY
	LONG_L	t0, TI_FLAGS($28)	# syscall tracing enabled?
	and	t0, t1, t0
	bnez	t0, syscall_trace_entry

syscall_common:
	dsubu	t2, v0, __NR_64_Linux
	sltiu   t0, t2, __NR_64_Linux_syscalls
	beqz	t0, illegal_syscall

	dsll	t0, t2, 3		# offset into table
	dla	t2, sys_call_table
	daddu	t0, t2, t0
	ld	t2, (t0)		# syscall routine
	beqz	t2, illegal_syscall

	jalr	t2			# Do The Real Thing (TM)

	li	t0, -EMAXERRNO - 1	# error?
	sltu	t0, t0, v0
	sd	t0, PT_R7(sp)		# set error flag
	beqz	t0, 1f

	ld	t1, PT_R2(sp)		# syscall number
	dnegu	v0			# error
	sd	t1, PT_R0(sp)		# save it for syscall restarting
1:	sd	v0, PT_R2(sp)		# result

n64_syscall_exit:

Annotation

Implementation Notes