/*
* S390 low-level entry points.
*
* Copyright IBM Corp. 1999, 2012
* 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/init.h>
#include <linux/linkage.h>
#include <asm/cache.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>
#include <asm/sigp.h>
__PT_R0 = __PT_GPRS
__PT_R1 = __PT_GPRS + 4
__PT_R2 = __PT_GPRS + 8
__PT_R3 = __PT_GPRS + 12
__PT_R4 = __PT_GPRS + 16
__PT_R5 = __PT_GPRS + 20
__PT_R6 = __PT_GPRS + 24
__PT_R7 = __PT_GPRS + 28
__PT_R8 = __PT_GPRS + 32
__PT_R9 = __PT_GPRS + 36
__PT_R10 = __PT_GPRS + 40
__PT_R11 = __PT_GPRS + 44
__PT_R12 = __PT_GPRS + 48
__PT_R13 = __PT_GPRS + 524
__PT_R14 = __PT_GPRS + 56
__PT_R15 = __PT_GPRS + 60
_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
_TIF_MCCK_PENDING | _TIF_PER_TRAP )
_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
_TIF_MCCK_PENDING)
_TIF_TRACE = (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
_TIF_SYSCALL_TRACEPOINT)
STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
STACK_SIZE = 1 << STACK_SHIFT
#define BASED(name) name-system_call(%r13)
.macro TRACE_IRQS_ON
#ifdef CONFIG_TRACE_IRQFLAGS
basr %r2,%r0
l %r1,BASED(.Lhardirqs_on)
basr %r14,%r1 # call trace_hardirqs_on_caller
#endif
.endm
.macro TRACE_IRQS_OFF
#ifdef CONFIG_TRACE_IRQFLAGS
basr %r2,%r0
l %r1,BASED(.Lhardirqs_off)
basr %r14,%r1 # call trace_hardirqs_off_caller
#endif
.endm
.macro LOCKDEP_SYS_EXIT
#ifdef CONFIG_LOCKDEP
tm __PT_PSW+1(%r11),0x01 # returning to user ?
jz .+10
l %r1,BASED(.Llockdep_sys_exit)
basr %r14,%r1 # call lockdep_sys_exit
#endif
.endm
.macro CHECK_STACK stacksize,savearea
#ifdef CONFIG_CHECK_STACK
tml %r15,\stacksize - CONFIG_STACK_GUARD
la %r14,\savearea
jz stack_overflow
#endif
.endm
.macro SWITCH_ASYNC savearea,stack,shift
tmh %r8,0x0001 # interrupting from user ?
jnz 1f
lr %r14,%r9
sl %r14,BASED(.Lcritical_start)
cl %r14,BASED(.Lcritical_length)
jhe 0f
la %r11,\savearea # inside critical section, do cleanup
bras %r14,cleanup_critical
tmh %r8,0x0001 # retest problem state after cleanup
jnz 1f
0: l %r14,\stack # are we already on the target stack?
slr %r14,%r15
sra %r14,\shift
jnz 1f
CHECK_STACK 1<<\shift,\savearea
j 2f
1: l %r15,\stack # load target stack
2: ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
la %r11,STACK_FRAME_OVERHEAD(%r15)
.endm
.macro ADD64 high,low,timer
al \high,\timer
al \low,4+\timer
brc 12,.+8
ahi \high,1
.endm
.macro SUB64 high,low,timer
sl \high,\timer
sl \low,4+\timer
brc 3,.+8
ahi \high,-1
.endm
.macro UPDATE_VTIME high,low,enter_timer
lm \high,\low,__LC_EXIT_TIMER
SUB64 \high,\low,\enter_timer
ADD64 \high,\low,__LC_USER_TIMER
stm \high,\low,__LC_USER_TIMER
lm \high,\low,__LC_LAST_UPDATE_TIMER
SUB64 \high,\low,__LC_EXIT_TIMER
ADD64 \high,\low,__LC_SYSTEM_TIMER
stm \high,\low,__LC_SYSTEM_TIMER
mvc __LC_LAST_UPDATE_TIMER(8),\enter_timer
.endm
.macro REENABLE_IRQS
st %r8,__LC_RETURN_PSW
ni __LC_RETURN_PSW,0xbf
ssm __LC_RETURN_PSW
.endm
.section .kprobes.text, "ax"
/*
* Scheduler resume function, called by switch_to
* gpr2 = (task_struct *) prev
* gpr3 = (task_struct *) next
* Returns:
* gpr2 = prev
*/
ENTRY(__switch_to)
stm %r6,%r15,__SF_GPRS(%r15) # store gprs of prev task
st %r15,__THREAD_ksp(%r2) # store kernel stack of prev
l %r4,__THREAD_info(%r2) # get thread_info of prev
l %r5,__THREAD_info(%r3) # get thread_info of next
lr %r15,%r5
ahi %r15,STACK_SIZE # end of kernel stack of next
st %r3,__LC_CURRENT # store task struct of next
st %r5,__LC_THREAD_INFO # store thread info of next
st %r15,__LC_KERNEL_STACK # store end of kernel stack
lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4
mvc __LC_CURRENT_PID(4,%r0),__TASK_pid(%r3) # store pid of next
l %r15,__THREAD_ksp(%r3) # load kernel stack of next
tm __TI_flags+3(%r4),_TIF_MCCK_PENDING # machine check pending?
jz 0f
ni __TI_flags+3(%r4),255-_TIF_MCCK_PENDING # clear flag in prev
oi __TI_flags+3(%r5),_TIF_MCCK_PENDING # set it in next
0: lm %r6,%r15,__SF_GPRS(%r15) # load gprs of next task
br %r14
__critical_start:
/*
* SVC interrupt handler routine. System calls are synchronous events and
* are executed with interrupts enabled.
*/
ENTRY(system_call)
stpt __LC_SYNC_ENTER_TIMER
sysc_stm:
stm %r8,%r15,__LC_SAVE_AREA_SYNC
l %r12,__LC_THREAD_INFO
l %r13,__LC_SVC_NEW_PSW+4
sysc_per:
l %r15,__LC_KERNEL_STACK
ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
la %r11,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs
sysc_vtime:
UPDATE_VTIME %r8,%r9,__LC_SYNC_ENTER_TIMER
stm %r0,%r7,__PT_R0(%r11)
mvc __PT_R8(32,%r11),__LC_SAVE_AREA_SYNC
mvc __PT_PSW(8,%r11),__LC_SVC_OLD_PSW
mvc __PT_INT_CODE(4,%r11),__LC_SVC_ILC
sysc_do_svc:
oi __TI_flags+3(%r12),_TIF_SYSCALL
lh %r8,__PT_INT_CODE+2(%r11)
sla %r8,2 # shift and test for svc0
jnz sysc_nr_ok
# svc 0: system call number in %r1
cl %r1,BASED(.Lnr_syscalls)
jnl sysc_nr_ok
sth %r1,__PT_INT_CODE+2(%r11)
lr %r8,%r1
sla %r8,2
sysc_nr_ok:
l %r10,BASED(.Lsys_call_table) # 31 bit system call table
xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
st %r2,__PT_ORIG_GPR2(%r11)
st %r7,STACK_FRAME_OVERHEAD(%r15)
l %r9,0(%r8,%r10) # get system call addr.
tm __TI_flags+2(%r12),_TIF_TRACE >> 8
jnz sysc_tracesys
basr %r14,%r9 # call sys_xxxx
st %r2,__PT_R2(%r11) # store return value
sysc_return:
LOCKDEP_SYS_EXIT
sysc_tif:
tm __PT_PSW+1(%r11),0x01 # returning to user ?
jno sysc_restore
tm __TI_flags+3(%r12),_TIF_WORK_SVC
jnz sysc_work # check for work
ni __TI_flags+3(%r12),255-_TIF_SYSCALL
sysc_restore:
mvc __LC_RETURN_PSW(8),__PT_PSW(%r11)
stpt __LC_EXIT_TIMER
lm %r0,%r15,__PT_R0(%r11)
lpsw __LC_RETURN_PSW
sysc_done:
#
# One of the work bits is on. Find out which one.
#
sysc_work:
tm __TI_flags+3(%r12),_TIF_MCCK_PENDING
jo sysc_mcck_pending
tm __TI_flags+3(%r12),_TIF_NEED_RESCHED
jo sysc_reschedule
tm __TI_flags+3(%r12),_TIF_PER_TRAP
jo sysc_singlestep
tm __TI_flags+3(%r12),_TIF_SIGPENDING
jo sysc_sigpending
tm __TI_flags+3(%r12),_TIF_NOTIFY_RESUME
jo sysc_notify_resume
j sysc_return # beware of critical section cleanup
#
# _TIF_NEED_RESCHED is set, call schedule
#
sysc_reschedule:
l %r1,BASED(.Lschedule)
la %r14,BASED(sysc_return)
br %r1 # call schedule
#
# _TIF_MCCK_PENDING is set, call handler
#
sysc_mcck_pending:
l %r1,BASED(.Lhandle_mcck)
la %r14,BASED(sysc_return)
br %r1 # TIF bit will be cleared by handler
#
# _TIF_SIGPENDING is set, call do_signal
#
sysc_sigpending:
lr %r2,%r11 # pass pointer to pt_regs
l %r1,BASED(.Ldo_signal)
basr %r14,%r1 # call do_signal
tm __TI_flags+3(%r12),_TIF_SYSCALL
jno sysc_return
lm %r2,%r7,__PT_R2(%r11) # load svc arguments
xr %r8,%r8 # svc 0 returns -ENOSYS
clc __PT_INT_CODE+2(2,%r11),BASED(.Lnr_syscalls+2)
jnl sysc_nr_ok # invalid svc number -> do svc 0
lh %r8,__PT_INT_CODE+2(%r11) # load new svc number
sla %r8,2
j sysc_nr_ok # restart svc
#
# _TIF_NOTIFY_RESUME is set, call do_notify_resume
#
sysc_notify_resume:
lr %r2,%r11 # pass pointer to pt_regs
l %r1,BASED(.Ldo_notify_resume)
la %r14,BASED(sysc_return)
br %r1 # call do_notify_resume
#
# _TIF_PER_TRAP is set, call do_per_trap
#
sysc_singlestep:
ni __TI_flags+3(%r12),255-_TIF_PER_TRAP
lr %r2,%r11 # pass pointer to pt_regs
l %r1,BASED(.Ldo_per_trap)
la %r14,BASED(sysc_return)
br %r1 # call do_per_trap
#
# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
# and after the system call
#
sysc_tracesys:
l %r1,BASED(.Ltrace_enter)
lr %r2,%r11 # pass pointer to pt_regs
la %r3,0
xr %r0,%r0
icm %r0,3,__PT_INT_CODE+2(%r11)
st %r0,__PT_R2(%r11)
basr %r14,%r1 # call do_syscall_trace_enter
cl %r2,BASED(.Lnr_syscalls)
jnl sysc_tracenogo
lr %r8,%r2
sll %r8,2
l %r9,0(%r8,%r10)
sysc_tracego:
lm %r3,%r7,__PT_R3(%r11)
st %r7,STACK_FRAME_OVERHEAD(%r15)
l %r2,__PT_ORIG_GPR2(%r11)
basr %r14,%r9 # call sys_xxx
st %r2,__PT_R2(%r11) # store return value
sysc_tracenogo:
tm __TI_flags+2(%r12),_TIF_TRACE >> 8
jz sysc_return
l %r1,BASED(.Ltrace_exit)
lr %r2,%r11 # pass pointer to pt_regs
la %r14,BASED(sysc_return)
br %r1 # call do_syscall_trace_exit
#
# a new process exits the kernel with ret_from_fork
#
ENTRY(ret_from_fork)
la %r11,STACK_FRAME_OVERHEAD(%r15)
l %r12,__LC_THREAD_INFO
l %r13,__LC_SVC_NEW_PSW+4
l %r1,BASED(.Lschedule_tail)
basr %r14,%r1 # call schedule_tail
TRACE_IRQS_ON
ssm __LC_SVC_NEW_PSW # reenable interrupts
tm __PT_PSW+1(%r11),0x01 # forking a kernel thread ?
jne sysc_tracenogo
# it's a kernel thread
lm %r9,%r10,__PT_R9(%r11) # load gprs
ENTRY(kernel_thread_starter)
la %r2,0(%r10)
basr %r14,%r9
j sysc_tracenogo
/*
* Program check handler routine
*/
ENTRY(pgm_check_handler)
stpt __LC_SYNC_ENTER_TIMER
stm %r8,%r15,__LC_SAVE_AREA_SYNC
l %r12,__LC_THREAD_INFO
l %r13,__LC_SVC_NEW_PSW+4
lm %r8,%r9,__LC_PGM_OLD_PSW
tmh %r8,0x0001 # test problem state bit
jnz 1f # -> fault in user space
tmh %r8,0x4000 # PER bit set in old PSW ?
jnz 0f # -> enabled, can't be a double fault
tm __LC_PGM_ILC+3,0x80 # check for per exception
jnz pgm_svcper # -> single stepped svc
0: CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC
j 2f
1: UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER
l %r15,__LC_KERNEL_STACK
2: ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
la %r11,STACK_FRAME_OVERHEAD(%r15)
stm %r0,%r7,__PT_R0(%r11)
mvc __PT_R8(32,%r11),__LC_SAVE_AREA_SYNC
stm %r8,%r9,__PT_PSW(%r11)
mvc __PT_INT_CODE(4,%r11),__LC_PGM_ILC
mvc __PT_INT_PARM_LONG(4,%r11),__LC_TRANS_EXC_CODE
tm __LC_PGM_ILC+3,0x80 # check for per exception
jz 0f
l %r1,__TI_task(%r12)
tmh %r8,0x0001 # kernel per event ?
jz pgm_kprobe
oi __TI_flags+3(%r12),_TIF_PER_TRAP
mvc __THREAD_per_address(4,%r1),__LC_PER_ADDRESS
mvc __THREAD_per_cause(2,%r1),__LC_PER_CAUSE
mvc __THREAD_per_paid(1,%r1),__LC_PER_PAID
0: REENABLE_IRQS
xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
l %r1,BASED(.Ljump_table)
la %r10,0x7f
n %r10,__PT_INT_CODE(%r11)
je sysc_return
sll %r10,2
l %r1,0(%r10,%r1) # load address of handler routine
lr %r2,%r11 # pass pointer to pt_regs
basr %r14,%r1 # branch to interrupt-handler
j sysc_return
#
# PER event in supervisor state, must be kprobes
#
pgm_kprobe:
REENABLE_IRQS
xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
l %r1,BASED(.Ldo_per_trap)
lr %r2,%r11 # pass pointer to pt_regs
basr %r14,%r1 # call do_per_trap
j sysc_return
#
# single stepped system call
#
pgm_svcper:
oi __TI_flags+3(%r12),_TIF_PER_TRAP
mvc __LC_RETURN_PSW(4),__LC_SVC_NEW_PSW
mvc __LC_RETURN_PSW+4(4),BASED(.Lsysc_per)
lpsw __LC_RETURN_PSW # branch to sysc_per and enable irqs
/*
* IO interrupt handler routine
*/
ENTRY(io_int_handler)
stck __LC_INT_CLOCK
stpt __LC_ASYNC_ENTER_TIMER
stm %r8,%r15,__LC_SAVE_AREA_ASYNC
l %r12,__LC_THREAD_INFO
l %r13,__LC_SVC_NEW_PSW+4
lm %r8,%r9,__LC_IO_OLD_PSW
tmh %r8,0x0001 # interrupting from user ?
jz io_skip
UPDATE_VTIME %r14,%r15,__LC_ASYNC_ENTER_TIMER
io_skip:
SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT
stm %r0,%r7,__PT_R0(%r11)
mvc __PT_R8(32,%r11),__LC_SAVE_AREA_ASYNC
stm %r8,%r9,__PT_PSW(%r11)
TRACE_IRQS_OFF
xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
l %r1,BASED(.Ldo_IRQ)
lr %r2,%r11 # pass pointer to pt_regs
basr %r14,%r1 # call do_IRQ
io_return:
LOCKDEP_SYS_EXIT
TRACE_IRQS_ON
io_tif:
tm __TI_flags+3(%r12),_TIF_WORK_INT
jnz io_work # there is work to do (signals etc.)
io_restore:
mvc __LC_RETURN_PSW(8),__PT_PSW(%r11)
stpt __LC_EXIT_TIMER
lm %r0,%r15,__PT_R0(%r11)
lpsw __LC_RETURN_PSW
io_done:
#
# There is work todo, find out in which context we have been interrupted:
# 1) if we return to user space we can do all _TIF_WORK_INT work
# 2) if we return to kernel code and preemptive scheduling is enabled check
# the preemption counter and if it is zero call preempt_schedule_irq
# Before any work can be done, a switch to the kernel stack is required.
#
io_work:
tm __PT_PSW+1(%r11),0x01 # returning to user ?
jo io_work_user # yes -> do resched & signal
#ifdef CONFIG_PREEMPT
# check for preemptive scheduling
icm %r0,15,__TI_precount(%r12)
jnz io_restore # preemption disabled
tm __TI_flags+3(%r12),_TIF_NEED_RESCHED
jno io_restore
# switch to kernel stack
l %r1,__PT_R15(%r11)
ahi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1)
la %r11,STACK_FRAME_OVERHEAD(%r1)
lr %r15,%r1
# TRACE_IRQS_ON already done at io_return, call
# TRACE_IRQS_OFF to keep things symmetrical
TRACE_IRQS_OFF
l %r1,BASED(.Lpreempt_irq)
basr %r14,%r1 # call preempt_schedule_irq
j io_return
#else
j io_restore
#endif
#
# Need to do work before returning to userspace, switch to kernel stack
#
io_work_user:
l %r1,__LC_KERNEL_STACK
ahi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1)
la %r11,STACK_FRAME_OVERHEAD(%r1)
lr %r15,%r1
#
# One of the work bits is on. Find out which one.
# Checked are: _TIF_SIGPENDING, _TIF_NOTIFY_RESUME, _TIF_NEED_RESCHED
# and _TIF_MCCK_PENDING
#
io_work_tif:
tm __TI_flags+3(%r12),_TIF_MCCK_PENDING
jo io_mcck_pending
tm __TI_flags+3(%r12),_TIF_NEED_RESCHED
jo io_reschedule
tm __TI_flags+3(%r12),_TIF_SIGPENDING
jo io_sigpending
tm __TI_flags+3(%r12),_TIF_NOTIFY_RESUME
jo io_notify_resume
j io_return # beware of critical section cleanup
#
# _TIF_MCCK_PENDING is set, call handler
#
io_mcck_pending:
# TRACE_IRQS_ON already done at io_return
l %r1,BASED(.Lhandle_mcck)
basr %r14,%r1 # TIF bit will be cleared by handler
TRACE_IRQS_OFF
j io_return
#
# _TIF_NEED_RESCHED is set, call schedule
#
io_reschedule:
# TRACE_IRQS_ON already done at io_return
l %r1,BASED(.Lschedule)
ssm __LC_SVC_NEW_PSW # reenable interrupts
basr %r14,%r1 # call scheduler
ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
TRACE_IRQS_OFF
j io_return
#
# _TIF_SIGPENDING is set, call do_signal
#
io_sigpending:
# TRACE_IRQS_ON already done at io_return
l %r1,BASED(.Ldo_signal)
ssm __LC_SVC_NEW_PSW # reenable interrupts
lr %r2,%r11 # pass pointer to pt_regs
basr %r14,%r1 # call do_signal
ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
TRACE_IRQS_OFF
j io_return
#
# _TIF_SIGPENDING is set, call do_signal
#
io_notify_resume:
# TRACE_IRQS_ON already done at io_return
l %r1,BASED(.Ldo_notify_resume)
ssm __LC_SVC_NEW_PSW # reenable interrupts
lr %r2,%r11 # pass pointer to pt_regs
basr %r14,%r1 # call do_notify_resume
ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
TRACE_IRQS_OFF
j io_return
/*
* External interrupt handler routine
*/
ENTRY(ext_int_handler)
stck __LC_INT_CLOCK
stpt __LC_ASYNC_ENTER_TIMER
stm %r8,%r15,__LC_SAVE_AREA_ASYNC
l %r12,__LC_THREAD_INFO
l %r13,__LC_SVC_NEW_PSW+4
lm %r8,%r9,__LC_EXT_OLD_PSW
tmh %r8,0x0001 # interrupting from user ?
jz ext_skip
UPDATE_VTIME %r14,%r15,__LC_ASYNC_ENTER_TIMER
ext_skip:
SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT
stm %r0,%r7,__PT_R0(%r11)
mvc __PT_R8(32,%r11),__LC_SAVE_AREA_ASYNC
stm %r8,%r9,__PT_PSW(%r11)
TRACE_IRQS_OFF
lr %r2,%r11 # pass pointer to pt_regs
l %r3,__LC_EXT_CPU_ADDR # get cpu address + interruption code
l %r4,__LC_EXT_PARAMS # get external parameters
l %r1,BASED(.Ldo_extint)
basr %r14,%r1 # call do_extint
j io_return
/*
* Load idle PSW. The second "half" of this function is in cleanup_idle.
*/
ENTRY(psw_idle)
st %r3,__SF_EMPTY(%r15)
basr %r1,0
la %r1,psw_idle_lpsw+4-.(%r1)
st %r1,__SF_EMPTY+4(%r15)
oi __SF_EMPTY+4(%r15),0x80
stck __CLOCK_IDLE_ENTER(%r2)
stpt __TIMER_IDLE_ENTER(%r2)
psw_idle_lpsw:
lpsw __SF_EMPTY(%r15)
br %r14
psw_idle_end:
__critical_end:
/*
* Machine check handler routines
*/
ENTRY(mcck_int_handler)
stck __LC_MCCK_CLOCK
spt __LC_CPU_TIMER_SAVE_AREA # revalidate cpu timer
lm %r0,%r15,__LC_GPREGS_SAVE_AREA # revalidate gprs
l %r12,__LC_THREAD_INFO
l %r13,__LC_SVC_NEW_PSW+4
lm %r8,%r9,__LC_MCK_OLD_PSW
tm __LC_MCCK_CODE,0x80 # system damage?
jo mcck_panic # yes -> rest of mcck code invalid
la %r14,__LC_CPU_TIMER_SAVE_AREA
mvc __LC_MCCK_ENTER_TIMER(8),0(%r14)
tm __LC_MCCK_CODE+5,0x02 # stored cpu timer value valid?
jo 3f
la %r14,__LC_SYNC_ENTER_TIMER
clc 0(8,%r14),__LC_ASYNC_ENTER_TIMER
jl 0f
la %r14,__LC_ASYNC_ENTER_TIMER
0: clc 0(8,%r14),__LC_EXIT_TIMER
jl 1f
la %r14,__LC_EXIT_TIMER
1: clc 0(8,%r14),__LC_LAST_UPDATE_TIMER
jl 2f
la %r14,__LC_LAST_UPDATE_TIMER
2: spt 0(%r14)
mvc __LC_MCCK_ENTER_TIMER(8),0(%r14)
3: tm __LC_MCCK_CODE+2,0x09 # mwp + ia of old psw valid?
jno mcck_panic # no -> skip cleanup critical
tm %r8,0x0001 # interrupting from user ?
jz mcck_skip
UPDATE_VTIME %r14,%r15,__LC_MCCK_ENTER_TIMER
mcck_skip:
SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+32,__LC_PANIC_STACK,PAGE_SHIFT
stm %r0,%r7,__PT_R0(%r11)
mvc __PT_R8(32,%r11),__LC_GPREGS_SAVE_AREA+32
stm %r8,%r9,__PT_PSW(%r11)
xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
l %r1,BASED(.Ldo_machine_check)
lr %r2,%r11 # pass pointer to pt_regs
basr %r14,%r1 # call s390_do_machine_check
tm __PT_PSW+1(%r11),0x01 # returning to user ?
jno mcck_return
l %r1,__LC_KERNEL_STACK # switch to kernel stack
ahi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1)
la %r11,STACK_FRAME_OVERHEAD(%r15)
lr %r15,%r1
ssm __LC_PGM_NEW_PSW # turn dat on, keep irqs off
tm __TI_flags+3(%r12),_TIF_MCCK_PENDING
jno mcck_return
TRACE_IRQS_OFF
l %r1,BASED(.Lhandle_mcck)
basr %r14,%r1 # call s390_handle_mcck
TRACE_IRQS_ON
mcck_return:
mvc __LC_RETURN_MCCK_PSW(8),__PT_PSW(%r11) # move return PSW
tm __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
jno 0f
lm %r0,%r15,__PT_R0(%r11)
stpt __LC_EXIT_TIMER
lpsw __LC_RETURN_MCCK_PSW
0: lm %r0,%r15,__PT_R0(%r11)
lpsw __LC_RETURN_MCCK_PSW
mcck_panic:
l %r14,__LC_PANIC_STACK
slr %r14,%r15
sra %r14,PAGE_SHIFT
jz 0f
l %r15,__LC_PANIC_STACK
0: ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
j mcck_skip
#
# PSW restart interrupt handler
#
ENTRY(restart_int_handler)
st %r15,__LC_SAVE_AREA_RESTART
l %r15,__LC_RESTART_STACK
ahi %r15,-__PT_SIZE # create pt_regs on stack
xc 0(__PT_SIZE,%r15),0(%r15)
stm %r0,%r14,__PT_R0(%r15)
mvc __PT_R15(4,%r15),__LC_SAVE_AREA_RESTART
mvc __PT_PSW(8,%r15),__LC_RST_OLD_PSW # store restart old psw
ahi %r15,-STACK_FRAME_OVERHEAD # create stack frame on stack
xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15)
l %r1,__LC_RESTART_FN # load fn, parm & source cpu
l %r2,__LC_RESTART_DATA
l %r3,__LC_RESTART_SOURCE
ltr %r3,%r3 # test source cpu address
jm 1f # negative -> skip source stop
0: sigp %r4,%r3,SIGP_SENSE # sigp sense to source cpu
brc 10,0b # wait for status stored
1: basr %r14,%r1 # call function
stap __SF_EMPTY(%r15) # store cpu address
lh %r3,__SF_EMPTY(%r15)
2: sigp %r4,%r3,SIGP_STOP # sigp stop to current cpu
brc 2,2b
3: j 3b
.section .kprobes.text, "ax"
#ifdef CONFIG_CHECK_STACK
/*
* The synchronous or the asynchronous stack overflowed. We are dead.
* No need to properly save the registers, we are going to panic anyway.
* Setup a pt_regs so that show_trace can provide a good call trace.
*/
stack_overflow:
l %r15,__LC_PANIC_STACK # change to panic stack
ahi %r15,-__PT_SIZE # create pt_regs
stm %r0,%r7,__PT_R0(%r15)
stm %r8,%r9,__PT_PSW(%r15)
mvc __PT_R8(32,%r11),0(%r14)
lr %r15,%r11
ahi %r15,-STACK_FRAME_OVERHEAD
l %r1,BASED(1f)
xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
lr %r2,%r11 # pass pointer to pt_regs
br %r1 # branch to kernel_stack_overflow
1: .long kernel_stack_overflow
#endif
cleanup_table:
.long system_call + 0x80000000
.long sysc_do_svc + 0x80000000
.long sysc_tif + 0x80000000
.long sysc_restore + 0x80000000
.long sysc_done + 0x80000000
.long io_tif + 0x80000000
.long io_restore + 0x80000000
.long io_done + 0x80000000
.long psw_idle + 0x80000000
.long psw_idle_end + 0x80000000
cleanup_critical:
cl %r9,BASED(cleanup_table) # system_call
jl 0f
cl %r9,BASED(cleanup_table+4) # sysc_do_svc
jl cleanup_system_call
cl %r9,BASED(cleanup_table+8) # sysc_tif
jl 0f
cl %r9,BASED(cleanup_table+12) # sysc_restore
jl cleanup_sysc_tif
cl %r9,BASED(cleanup_table+16) # sysc_done
jl cleanup_sysc_restore
cl %r9,BASED(cleanup_table+20) # io_tif
jl 0f
cl %r9,BASED(cleanup_table+24) # io_restore
jl cleanup_io_tif
cl %r9,BASED(cleanup_table+28) # io_done
jl cleanup_io_restore
cl %r9,BASED(cleanup_table+32) # psw_idle
jl 0f
cl %r9,BASED(cleanup_table+36) # psw_idle_end
jl cleanup_idle
0: br %r14
cleanup_system_call:
# check if stpt has been executed
cl %r9,BASED(cleanup_system_call_insn)
jh 0f
mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
chi %r11,__LC_SAVE_AREA_ASYNC
je 0f
mvc __LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER
0: # check if stm has been executed
cl %r9,BASED(cleanup_system_call_insn+4)
jh 0f
mvc __LC_SAVE_AREA_SYNC(32),0(%r11)
0: # set up saved registers r12, and r13
st %r12,16(%r11) # r12 thread-info pointer
st %r13,20(%r11) # r13 literal-pool pointer
# check if the user time calculation has been done
cl %r9,BASED(cleanup_system_call_insn+8)
jh 0f
l %r10,__LC_EXIT_TIMER
l %r15,__LC_EXIT_TIMER+4
SUB64 %r10,%r15,__LC_SYNC_ENTER_TIMER
ADD64 %r10,%r15,__LC_USER_TIMER
st %r10,__LC_USER_TIMER
st %r15,__LC_USER_TIMER+4
0: # check if the system time calculation has been done
cl %r9,BASED(cleanup_system_call_insn+12)
jh 0f
l %r10,__LC_LAST_UPDATE_TIMER
l %r15,__LC_LAST_UPDATE_TIMER+4
SUB64 %r10,%r15,__LC_EXIT_TIMER
ADD64 %r10,%r15,__LC_SYSTEM_TIMER
st %r10,__LC_SYSTEM_TIMER
st %r15,__LC_SYSTEM_TIMER+4
0: # update accounting time stamp
mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
# set up saved register 11
l %r15,__LC_KERNEL_STACK
ahi %r15,-__PT_SIZE
st %r15,12(%r11) # r11 pt_regs pointer
# fill pt_regs
mvc __PT_R8(32,%r15),__LC_SAVE_AREA_SYNC
stm %r0,%r7,__PT_R0(%r15)
mvc __PT_PSW(8,%r15),__LC_SVC_OLD_PSW
mvc __PT_INT_CODE(4,%r15),__LC_SVC_ILC
# setup saved register 15
ahi %r15,-STACK_FRAME_OVERHEAD
st %r15,28(%r11) # r15 stack pointer
# set new psw address and exit
l %r9,BASED(cleanup_table+4) # sysc_do_svc + 0x80000000
br %r14
cleanup_system_call_insn:
.long system_call + 0x80000000
.long sysc_stm + 0x80000000
.long sysc_vtime + 0x80000000 + 36
.long sysc_vtime + 0x80000000 + 76
cleanup_sysc_tif:
l %r9,BASED(cleanup_table+8) # sysc_tif + 0x80000000
br %r14
cleanup_sysc_restore:
cl %r9,BASED(cleanup_sysc_restore_insn)
jhe 0f
l %r9,12(%r11) # get saved pointer to pt_regs
mvc __LC_RETURN_PSW(8),__PT_PSW(%r9)
mvc 0(32,%r11),__PT_R8(%r9)
lm %r0,%r7,__PT_R0(%r9)
0: lm %r8,%r9,__LC_RETURN_PSW
br %r14
cleanup_sysc_restore_insn:
.long sysc_done - 4 + 0x80000000
cleanup_io_tif:
l %r9,BASED(cleanup_table+20) # io_tif + 0x80000000
br %r14
cleanup_io_restore:
cl %r9,BASED(cleanup_io_restore_insn)
jhe 0f
l %r9,12(%r11) # get saved r11 pointer to pt_regs
mvc __LC_RETURN_PSW(8),__PT_PSW(%r9)
mvc 0(32,%r11),__PT_R8(%r9)
lm %r0,%r7,__PT_R0(%r9)
0: lm %r8,%r9,__LC_RETURN_PSW
br %r14
cleanup_io_restore_insn:
.long io_done - 4 + 0x80000000
cleanup_idle:
# copy interrupt clock & cpu timer
mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_INT_CLOCK
mvc __TIMER_IDLE_EXIT(8,%r2),__LC_ASYNC_ENTER_TIMER
chi %r11,__LC_SAVE_AREA_ASYNC
je 0f
mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_MCCK_CLOCK
mvc __TIMER_IDLE_EXIT(8,%r2),__LC_MCCK_ENTER_TIMER
0: # check if stck has been executed
cl %r9,BASED(cleanup_idle_insn)
jhe 1f
mvc __CLOCK_IDLE_ENTER(8,%r2),__CLOCK_IDLE_EXIT(%r2)
mvc __TIMER_IDLE_ENTER(8,%r2),__TIMER_IDLE_EXIT(%r3)
1: # account system time going idle
lm %r9,%r10,__LC_STEAL_TIMER
ADD64 %r9,%r10,__CLOCK_IDLE_ENTER(%r2)
SUB64 %r9,%r10,__LC_LAST_UPDATE_CLOCK
stm %r9,%r10,__LC_STEAL_TIMER
mvc __LC_LAST_UPDATE_CLOCK(8),__CLOCK_IDLE_EXIT(%r2)
lm %r9,%r10,__LC_SYSTEM_TIMER
ADD64 %r9,%r10,__LC_LAST_UPDATE_TIMER
SUB64 %r9,%r10,__TIMER_IDLE_ENTER(%r2)
stm %r9,%r10,__LC_SYSTEM_TIMER
mvc __LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2)
# prepare return psw
n %r8,BASED(cleanup_idle_wait) # clear wait state bit
l %r9,24(%r11) # return from psw_idle
br %r14
cleanup_idle_insn:
.long psw_idle_lpsw + 0x80000000
cleanup_idle_wait:
.long 0xfffdffff
/*
* Integer constants
*/
.align 4
.Lnr_syscalls:
.long NR_syscalls
.Lvtimer_max:
.quad 0x7fffffffffffffff
/*
* Symbol constants
*/
.Ldo_machine_check: .long s390_do_machine_check
.Lhandle_mcck: .long s390_handle_mcck
.Ldo_IRQ: .long do_IRQ
.Ldo_extint: .long do_extint
.Ldo_signal: .long do_signal
.Ldo_notify_resume: .long do_notify_resume
.Ldo_per_trap: .long do_per_trap
.Ljump_table: .long pgm_check_table
.Lschedule: .long schedule
#ifdef CONFIG_PREEMPT
.Lpreempt_irq: .long preempt_schedule_irq
#endif
.Ltrace_enter: .long do_syscall_trace_enter
.Ltrace_exit: .long do_syscall_trace_exit
.Lschedule_tail: .long schedule_tail
.Lsys_call_table: .long sys_call_table
.Lsysc_per: .long sysc_per + 0x80000000
#ifdef CONFIG_TRACE_IRQFLAGS
.Lhardirqs_on: .long trace_hardirqs_on_caller
.Lhardirqs_off: .long trace_hardirqs_off_caller
#endif
#ifdef CONFIG_LOCKDEP
.Llockdep_sys_exit: .long lockdep_sys_exit
#endif
.Lcritical_start: .long __critical_start + 0x80000000
.Lcritical_length: .long __critical_end - __critical_start
.section .rodata, "a"
#define SYSCALL(esa,esame,emu) .long esa
.globl sys_call_table
sys_call_table:
#include "syscalls.S"
#undef SYSCALL
