path: root/arch/s390/kernel/entry64.S

/*
 *  arch/s390/kernel/entry64.S
 *    S390 low-level entry points.
 *
 *    Copyright (C) IBM Corp. 1999,2006
 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
 *		 Hartmut Penner (hp@de.ibm.com),
 *		 Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
 *		 Heiko Carstens <heiko.carstens@de.ibm.com>
 */

#include <linux/sys.h>
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/cache.h>
#include <asm/lowcore.h>
#include <asm/errno.h>
#include <asm/ptrace.h>
#include <asm/thread_info.h>
#include <asm/asm-offsets.h>
#include <asm/unistd.h>
#include <asm/page.h>

/*
 * Stack layout for the system_call stack entry.
 * The first few entries are identical to the user_regs_struct.
 */
SP_PTREGS    =	STACK_FRAME_OVERHEAD
SP_ARGS      =	STACK_FRAME_OVERHEAD + __PT_ARGS
SP_PSW	     =	STACK_FRAME_OVERHEAD + __PT_PSW
SP_R0	     =	STACK_FRAME_OVERHEAD + __PT_GPRS
SP_R1	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 8
SP_R2	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 16
SP_R3	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 24
SP_R4	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 32
SP_R5	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 40
SP_R6	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 48
SP_R7	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 56
SP_R8	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 64
SP_R9	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 72
SP_R10	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 80
SP_R11	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 88
SP_R12	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 96
SP_R13	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 104
SP_R14	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 112
SP_R15	     =	STACK_FRAME_OVERHEAD + __PT_GPRS + 120
SP_ORIG_R2   =	STACK_FRAME_OVERHEAD + __PT_ORIG_GPR2
SP_ILC	     =	STACK_FRAME_OVERHEAD + __PT_ILC
SP_SVCNR      =	STACK_FRAME_OVERHEAD + __PT_SVCNR
SP_SIZE      =	STACK_FRAME_OVERHEAD + __PT_SIZE

STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
STACK_SIZE  = 1 << STACK_SHIFT

_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
		 _TIF_MCCK_PENDING | _TIF_RESTART_SVC | _TIF_SINGLE_STEP )
_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
		 _TIF_MCCK_PENDING)

#define BASED(name) name-system_call(%r13)

#ifdef CONFIG_TRACE_IRQFLAGS
	.macro	TRACE_IRQS_ON
	 basr	%r2,%r0
	 brasl	%r14,trace_hardirqs_on_caller
	.endm

	.macro	TRACE_IRQS_OFF
	 basr	%r2,%r0
	 brasl	%r14,trace_hardirqs_off_caller
	.endm

	.macro TRACE_IRQS_CHECK
	basr	%r2,%r0
	tm	SP_PSW(%r15),0x03	# irqs enabled?
	jz	0f
	brasl	%r14,trace_hardirqs_on_caller
	j	1f
0:	brasl	%r14,trace_hardirqs_off_caller
1:
	.endm
#else
#define TRACE_IRQS_ON
#define TRACE_IRQS_OFF
#define TRACE_IRQS_CHECK
#endif

#ifdef CONFIG_LOCKDEP
	.macro	LOCKDEP_SYS_EXIT
	tm	SP_PSW+1(%r15),0x01	# returning to user ?
	jz	0f
	brasl	%r14,lockdep_sys_exit
0:
	.endm
#else
#define LOCKDEP_SYS_EXIT
#endif

	.macro	UPDATE_VTIME lc_from,lc_to,lc_sum
	lg	%r10,\lc_from
	slg	%r10,\lc_to
	alg	%r10,\lc_sum
	stg	%r10,\lc_sum
	.endm

/*
 * Register usage in interrupt handlers:
 *    R9  - pointer to current task structure
 *    R13 - pointer to literal pool
 *    R14 - return register for function calls
 *    R15 - kernel stack pointer
 */

	.macro	SAVE_ALL_BASE savearea
	stmg	%r12,%r15,\savearea
	larl	%r13,system_call
	.endm

	.macro	SAVE_ALL_SVC psworg,savearea
	la	%r12,\psworg
	lg	%r15,__LC_KERNEL_STACK	# problem state -> load ksp
	.endm

	.macro	SAVE_ALL_SYNC psworg,savearea
	la	%r12,\psworg
	tm	\psworg+1,0x01		# test problem state bit
	jz	2f			# skip stack setup save
	lg	%r15,__LC_KERNEL_STACK	# problem state -> load ksp
#ifdef CONFIG_CHECK_STACK
	j	3f
2:	tml	%r15,STACK_SIZE - CONFIG_STACK_GUARD
	jz	stack_overflow
3:
#endif
2:
	.endm

	.macro	SAVE_ALL_ASYNC psworg,savearea
	la	%r12,\psworg
	tm	\psworg+1,0x01		# test problem state bit
	jnz	1f			# from user -> load kernel stack
	clc	\psworg+8(8),BASED(.Lcritical_end)
	jhe	0f
	clc	\psworg+8(8),BASED(.Lcritical_start)
	jl	0f
	brasl	%r14,cleanup_critical