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kernel-hacking-2024-linux-s.../arch/s390/kernel/entry.S
Martin Schwidefsky 27f6b41662 s390/vtimer: rework virtual timer interface 
The current virtual timer interface is inherently per-cpu and hard to
use. The sole user of the interface is appldata which uses it to execute
a function after a specific amount of cputime has been used over all cpus.

Rework the virtual timer interface to hook into the cputime accounting.
This makes the interface independent from the CPU timer interrupts, and
makes the virtual timers global as opposed to per-cpu.
Overall the code is greatly simplified. The downside is that the accuracy
is not as good as the original implementation, but it is still good enough
for appldata.

Reviewed-by: Jan Glauber <jang@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-07-20 11:15:08 +02:00

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/*
* 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_SIGPENDING
jo sysc_sigpending
tm __TI_flags+3(%r12),_TIF_NOTIFY_RESUME
jo sysc_notify_resume
tm __TI_flags+3(%r12),_TIF_PER_TRAP
jo sysc_singlestep
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:
ni __TI_flags+3(%r12),255-_TIF_PER_TRAP # clear TIF_PER_TRAP
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_SYSCALL | _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
tm __PT_PSW+1(%r11),0x01 # forking a kernel thread ?
jo 0f
st %r15,__PT_R15(%r11) # store stack pointer for new kthread
0: l %r1,BASED(.Lschedule_tail)
basr %r14,%r1 # call schedule_tail
TRACE_IRQS_ON
ssm __LC_SVC_NEW_PSW # reenable interrupts
j sysc_tracenogo
#
# kernel_execve function needs to deal with pt_regs that is not
# at the usual place
#
ENTRY(kernel_execve)
stm %r12,%r15,48(%r15)
lr %r14,%r15
l %r13,__LC_SVC_NEW_PSW+4
ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
st %r14,__SF_BACKCHAIN(%r15)
la %r12,STACK_FRAME_OVERHEAD(%r15)
xc 0(__PT_SIZE,%r12),0(%r12)
l %r1,BASED(.Ldo_execve)
lr %r5,%r12
basr %r14,%r1 # call do_execve
ltr %r2,%r2
je 0f
ahi %r15,(STACK_FRAME_OVERHEAD + __PT_SIZE)
lm %r12,%r15,48(%r15)
br %r14
# execve succeeded.
0: ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
l %r15,__LC_KERNEL_STACK # load ksp
ahi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
la %r11,STACK_FRAME_OVERHEAD(%r15)
mvc 0(__PT_SIZE,%r11),0(%r12) # copy pt_regs
l %r12,__LC_THREAD_INFO
xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
ssm __LC_SVC_NEW_PSW # reenable interrupts
l %r1,BASED(.Lexecve_tail)
basr %r14,%r1 # call execve_tail
j sysc_return
/*
* 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
mvc __PT_R0(64,%r11),__LC_GPREGS_SAVE_AREA
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
.Ldo_execve: .long do_execve
.Lexecve_tail: .long execve_tail
.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
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