/*
* 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/processor.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>
#include <asm/irq.h>
__PT_R0 = __PT_GPRS
__PT_R1 = __PT_GPRS + 8
__PT_R2 = __PT_GPRS + 16
__PT_R3 = __PT_GPRS + 24
__PT_R4 = __PT_GPRS + 32
__PT_R5 = __PT_GPRS + 40
__PT_R6 = __PT_GPRS + 48
__PT_R7 = __PT_GPRS + 56
__PT_R8 = __PT_GPRS + 64
__PT_R9 = __PT_GPRS + 72
__PT_R10 = __PT_GPRS + 80
__PT_R11 = __PT_GPRS + 88
__PT_R12 = __PT_GPRS + 96
__PT_R13 = __PT_GPRS + 104
__PT_R14 = __PT_GPRS + 112
__PT_R15 = __PT_GPRS + 120
STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
STACK_SIZE = 1 << STACK_SHIFT
STACK_INIT = STACK_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE
_TIF_WORK = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
_TIF_UPROBE)
_TIF_TRACE = (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
_TIF_SYSCALL_TRACEPOINT)
_CIF_WORK = (_CIF_MCCK_PENDING | _CIF_ASCE)
_PIF_WORK = (_PIF_PER_TRAP)
#define BASED(name) name-system_call(%r13)
.macro TRACE_IRQS_ON
#ifdef CONFIG_TRACE_IRQFLAGS
basr %r2,%r0
brasl %r14,trace_hardirqs_on_caller
#endif
.endm
.macro TRACE_IRQS_OFF
#ifdef CONFIG_TRACE_IRQFLAGS
basr %r2,%r0
brasl %r14,trace_hardirqs_off_caller
#endif
.endm
.macro LOCKDEP_SYS_EXIT
#ifdef CONFIG_LOCKDEP
tm __PT_PSW+1(%r11),0x01 # returning to user ?
jz .+10
brasl %r14,lockdep_sys_exit
#endif
.endm
.macro LPP newpp
#if IS_ENABLED(CONFIG_KVM)
tm __LC_MACHINE_FLAGS+6,0x20 # MACHINE_FLAG_LPP
jz .+8
.insn s,0xb2800000,\newpp
#endif
.endm
.macro HANDLE_SIE_INTERCEPT scratch,reason
#if IS_ENABLED(CONFIG_KVM)
tmhh %r8,0x0001 # interrupting from user ?
jnz .+62
lgr \scratch,%r9
slg \scratch,BASED(.Lsie_critical)
clg \scratch,BASED(.Lsie_critical_length)
.if \reason==1
# Some program interrupts are suppressing (e.g. protection).
# We must also check the instruction after SIE in that case.
# do_protection_exception will rewind to .Lrewind_pad
jh .+42
.else
jhe .+42
.endif
lg %r14,__SF_EMPTY(%r15) # get control block pointer
LPP __SF_EMPTY+16(%r15) # set host id
ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE
lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
larl %r9,sie_exit # skip forward to sie_exit
mvi __SF_EMPTY+31(%r15),\reason # set exit reason
#endif
.endm
.macro CHECK_STACK stacksize,savearea
#ifdef CONFIG_CHECK_STACK
tml %r15,\stacksize - CONFIG_STACK_GUARD
lghi %r14,\savearea
jz stack_overflow
#endif
.endm
.macro SWITCH_ASYNC savearea,stack,shift
tmhh %r8,0x0001 # interrupting from user ?
jnz 1f
lgr %r14,%r9
slg %r14,BASED(.Lcritical_start)
clg %r14,BASED(.Lcritical_length)
jhe 0f
lghi %r11,\savearea # inside critical section, do cleanup
brasl %r14,cleanup_critical
tmhh %r8,0x0001 # retest problem state after cleanup
jnz 1f
0: lg %r14,\stack # are we already on the target stack?
slgr %r14,%r15
srag %r14,%r14,\shift
jnz 1f
CHECK_STACK 1<<\shift,\savearea
aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
j 2f
1: lg %r15,\stack # load target stack
2: la %r11,STACK_FRAME_OVERHEAD(%r15)
.endm
.macro UPDATE_VTIME scratch,enter_timer
lg \scratch,__LC_EXIT_TIMER
slg \scratch,\enter_timer
alg \scratch,__LC_USER_TIMER
stg \scratch,__LC_USER_TIMER
lg \scratch,__LC_LAST_UPDATE_TIMER
slg \scratch,__LC_EXIT_TIMER
alg \scratch,__LC_SYSTEM_TIMER
stg \scratch,__LC_SYSTEM_TIMER
mvc __LC_LAST_UPDATE_TIMER(8),\enter_timer
.endm
.macro LAST_BREAK scratch
srag \scratch,%r10,23
jz .+10
stg %r10,__TI_last_break(%r12)
.endm
.macro REENABLE_IRQS
stg %r8,__LC_RETURN_PSW
ni __LC_RETURN_PSW,0xbf
ssm __LC_RETURN_PSW
.endm
.macro STCK savearea
#ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
.insn s,0xb27c0000,\savearea # store clock fast
#else
.insn s,0xb2050000,\savearea # store clock
#endif
.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)
stmg %r6,%r15,__SF_GPRS(%r15) # store gprs of prev task
stg %r15,__THREAD_ksp(%r2) # store kernel stack of prev
lg %r4,__THREAD_info(%r2) # get thread_info of prev
lg %r5,__THREAD_info(%r3) # get thread_info of next
lgr %r15,%r5
aghi %r15,STACK_INIT # end of kernel stack of next
stg %r3,__LC_CURRENT # store task struct of next
stg %r5,__LC_THREAD_INFO # store thread info of next
stg %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(4,%r0),__TASK_pid(%r3) # store pid of next
lg %r15,__THREAD_ksp(%r3) # load kernel stack of next
lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task
br %r14
.L__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
.Lsysc_stmg:
stmg %r8,%r15,__LC_SAVE_AREA_SYNC
lg %r10,__LC_LAST_BREAK
lg %r12,__LC_THREAD_INFO
lghi %r14,_PIF_SYSCALL
.Lsysc_per:
lg %r15,__LC_KERNEL_STACK
la %r11,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs
.Lsysc_vtime:
UPDATE_VTIME %r13,__LC_SYNC_ENTER_TIMER
LAST_BREAK %r13
stmg %r0,%r7,__PT_R0(%r11)
mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
mvc __PT_PSW(16,%r11),__LC_SVC_OLD_PSW
mvc __PT_INT_CODE(4,%r11),__LC_SVC_ILC
stg %r14,__PT_FLAGS(%r11)
.Lsysc_do_svc:
lg %r10,__TI_sysc_table(%r12) # address of system call table
llgh %r8,__PT_INT_CODE+2(%r11)
slag %r8,%r8,2 # shift and test for svc 0
jnz .Lsysc_nr_ok
# svc 0: system call number in %r1
llgfr %r1,%r1 # clear high word in r1
cghi %r1,NR_syscalls
jnl .Lsysc_nr_ok
sth %r1,__PT_INT_CODE+2(%r11)
slag %r8,%r1,2
.Lsysc_nr_ok:
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
stg %r2,__PT_ORIG_GPR2(%r11)
stg %r7,STACK_FRAME_OVERHEAD(%r15)
lgf %r9,0(%r8,%r10) # get system call add.
tm __TI_flags+7(%r12),_TIF_TRACE
jnz .Lsysc_tracesys
basr %r14,%r9 # call sys_xxxx
stg %r2,__PT_R2(%r11) # store return value
.Lsysc_return:
LOCKDEP_SYS_EXIT
.Lsysc_tif:
tm __PT_PSW+1(%r11),0x01 # returning to user ?
jno .Lsysc_restore
tm __PT_FLAGS+7(%r11),_PIF_WORK
jnz .Lsysc_work
tm __TI_flags+7(%r12),_TIF_WORK
jnz .Lsysc_work # check for work
tm __LC_CPU_FLAGS+7,_CIF_WORK
jnz .Lsysc_work
.Lsysc_restore:
lg %r14,__LC_VDSO_PER_CPU
lmg %r0,%r10,__PT_R0(%r11)
mvc __LC_RETURN_PSW(16),__PT_PSW(%r11)
stpt __LC_EXIT_TIMER
mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
lmg %r11,%r15,__PT_R11(%r11)
lpswe __LC_RETURN_PSW
.Lsysc_done:
#
# One of the work bits is on. Find out which one.
#
.Lsysc_work:
tm __LC_CPU_FLAGS+7,_CIF_MCCK_PENDING
jo .Lsysc_mcck_pending
tm __TI_flags+7(%r12),_TIF_NEED_RESCHED
jo .Lsysc_reschedule
#ifdef CONFIG_UPROBES
tm __TI_flags+7(%r12),_TIF_UPROBE
jo .Lsysc_uprobe_notify
#endif
tm __PT_FLAGS+7(%r11),_PIF_PER_TRAP
jo .Lsysc_singlestep
tm __TI_flags+7(%r12),_TIF_SIGPENDING
jo .Lsysc_sigpending
tm __TI_flags+7(%r12),_TIF_NOTIFY_RESUME
jo .Lsysc_notify_resume
tm __LC_CPU_FLAGS+7,_CIF_ASCE
jo .Lsysc_uaccess
j .Lsysc_return # beware of critical section cleanup
#
# _TIF_NEED_RESCHED is set, call schedule
#
.Lsysc_reschedule:
larl %r14,.Lsysc_return
jg schedule
#
# _CIF_MCCK_PENDING is set, call handler
#
.Lsysc_mcck_pending:
larl %r14,.Lsysc_return
jg s390_handle_mcck # TIF bit will be cleared by handler
#
# _CIF_ASCE is set, load user space asce
#
.Lsysc_uaccess:
ni __LC_CPU_FLAGS+7,255-_CIF_ASCE
lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
j .Lsysc_return
#
# _TIF_SIGPENDING is set, call do_signal
#
.Lsysc_sigpending:
lgr %r2,%r11 # pass pointer to pt_regs
brasl %r14,do_signal
tm __PT_FLAGS+7(%r11),_PIF_SYSCALL
jno .Lsysc_return
lmg %r2,%r7,__PT_R2(%r11) # load svc arguments
lg %r10,__TI_sysc_table(%r12) # address of system call table
lghi %r8,0 # svc 0 returns -ENOSYS
llgh %r1,__PT_INT_CODE+2(%r11) # load new svc number
cghi %r1,NR_syscalls
jnl .Lsysc_nr_ok # invalid svc number -> do svc 0
slag %r8,%r1,2
j .Lsysc_nr_ok # restart svc
#
# _TIF_NOTIFY_RESUME is set, call do_notify_resume
#
.Lsysc_notify_resume:
lgr %r2,%r11 # pass pointer to pt_regs
larl %r14,.Lsysc_return
jg do_notify_resume
#
# _TIF_UPROBE is set, call uprobe_notify_resume
#
#ifdef CONFIG_UPROBES
.Lsysc_uprobe_notify:
lgr %r2,%r11 # pass pointer to pt_regs
larl %r14,.Lsysc_return
jg uprobe_notify_resume
#endif
#
# _PIF_PER_TRAP is set, call do_per_trap
#
.Lsysc_singlestep:
ni __PT_FLAGS+7(%r11),255-_PIF_PER_TRAP
lgr %r2,%r11 # pass pointer to pt_regs
larl %r14,.Lsysc_return
jg do_per_trap
#
# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
# and after the system call
#
.Lsysc_tracesys:
lgr %r2,%r11 # pass pointer to pt_regs
la %r3,0
llgh %r0,__PT_INT_CODE+2(%r11)
stg %r0,__PT_R2(%r11)
brasl %r14,do_syscall_trace_enter
lghi %r0,NR_syscalls
clgr %r0,%r2
jnh .Lsysc_tracenogo
sllg %r8,%r2,2
lgf %r9,0(%r8,%r10)
.Lsysc_tracego:
lmg %r3,%r7,__PT_R3(%r11)
stg %r7,STACK_FRAME_OVERHEAD(%r15)
lg %r2,__PT_ORIG_GPR2(%r11)
basr %r14,%r9 # call sys_xxx
stg %r2,__PT_R2(%r11) # store return value
.Lsysc_tracenogo:
tm __TI_flags+7(%r12),_TIF_TRACE
jz .Lsysc_return
lgr %r2,%r11 # pass pointer to pt_regs
larl %r14,.Lsysc_return
jg do_syscall_trace_exit
#
# a new process exits the kernel with ret_from_fork
#
ENTRY(ret_from_fork)
la %r11,STACK_FRAME_OVERHEAD(%r15)
lg %r12,__LC_THREAD_INFO
brasl %r14,schedule_tail
TRACE_IRQS_ON
ssm __LC_SVC_NEW_PSW # reenable interrupts
tm __PT_PSW+1(%r11),0x01 # forking a kernel thread ?
jne .Lsysc_tracenogo
# it's a kernel thread
lmg %r9,%r10,__PT_R9(%r11) # load gprs
ENTRY(kernel_thread_starter)
la %r2,0(%r10)
basr %r14,%r9
j .Lsysc_tracenogo
/*
* Program check handler routine
*/
ENTRY(pgm_check_handler)
stpt __LC_SYNC_ENTER_TIMER
stmg %r8,%r15,__LC_SAVE_AREA_SYNC
lg %r10,__LC_LAST_BREAK
lg %r12,__LC_THREAD_INFO
larl %r13,system_call
lmg %r8,%r9,__LC_PGM_OLD_PSW
HANDLE_SIE_INTERCEPT %r14,1
tmhh %r8,0x0001 # test problem state bit
jnz 1f # -> fault in user space
tmhh %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 .Lpgm_svcper # -> single stepped svc
0: CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC
aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
j 2f
1: UPDATE_VTIME %r14,__LC_SYNC_ENTER_TIMER
LAST_BREAK %r14
lg %r15,__LC_KERNEL_STACK
lg %r14,__TI_task(%r12)
lghi %r13,__LC_PGM_TDB
tm __LC_PGM_ILC+2,0x02 # check for transaction abort
jz 2f
mvc __THREAD_trap_tdb(256,%r14),0(%r13)
2: la %r11,STACK_FRAME_OVERHEAD(%r15)
stmg %r0,%r7,__PT_R0(%r11)
mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
stmg %r8,%r9,__PT_PSW(%r11)
mvc __PT_INT_CODE(4,%r11),__LC_PGM_ILC
mvc __PT_INT_PARM_LONG(8,%r11),__LC_TRANS_EXC_CODE
xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
stg %r10,__PT_ARGS(%r11)
tm __LC_PGM_ILC+3,0x80 # check for per exception
jz 0f
tmhh %r8,0x0001 # kernel per event ?
jz .Lpgm_kprobe
oi __PT_FLAGS+7(%r11),_PIF_PER_TRAP
mvc __THREAD_per_address(8,%r14),__LC_PER_ADDRESS
mvc __THREAD_per_cause(2,%r14),__LC_PER_CODE
mvc __THREAD_per_paid(1,%r14),__LC_PER_ACCESS_ID
0: REENABLE_IRQS
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
larl %r1,pgm_check_table
llgh %r10,__PT_INT_CODE+2(%r11)
nill %r10,0x007f
sll %r10,2
je .Lsysc_return
lgf %r1,0(%r10,%r1) # load address of handler routine
lgr %r2,%r11 # pass pointer to pt_regs
basr %r14,%r1 # branch to interrupt-handler
j .Lsysc_return
#
# PER event in supervisor state, must be kprobes
#
.Lpgm_kprobe:
REENABLE_IRQS
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
lgr %r2,%r11 # pass pointer to pt_regs
brasl %r14,do_per_trap
j .Lsysc_return
#
# single stepped system call
#
.Lpgm_svcper:
mvc __LC_RETURN_PSW(8),__LC_SVC_NEW_PSW
larl %r14,.Lsysc_per
stg %r14,__LC_RETURN_PSW+8
lghi %r14,_PIF_SYSCALL | _PIF_PER_TRAP
lpswe __LC_RETURN_PSW # branch to .Lsysc_per and enable irqs
/*
* IO interrupt handler routine
*/
ENTRY(io_int_handler)
STCK __LC_INT_CLOCK
stpt __LC_ASYNC_ENTER_TIMER
stmg %r8,%r15,__LC_SAVE_AREA_ASYNC
lg %r10,__LC_LAST_BREAK
lg %r12,__LC_THREAD_INFO
larl %r13,system_call
lmg %r8,%r9,__LC_IO_OLD_PSW
HANDLE_SIE_INTERCEPT %r14,2
SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT
tmhh %r8,0x0001 # interrupting from user?
jz .Lio_skip
UPDATE_VTIME %r14,__LC_ASYNC_ENTER_TIMER
LAST_BREAK %r14
.Lio_skip:
stmg %r0,%r7,__PT_R0(%r11)
mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
stmg %r8,%r9,__PT_PSW(%r11)
mvc __PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
TRACE_IRQS_OFF
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
.Lio_loop:
lgr %r2,%r11 # pass pointer to pt_regs
lghi %r3,IO_INTERRUPT
tm __PT_INT_CODE+8(%r11),0x80 # adapter interrupt ?
jz .Lio_call
lghi %r3,THIN_INTERRUPT
.Lio_call:
brasl %r14,do_IRQ
tm __LC_MACHINE_FLAGS+6,0x10 # MACHINE_FLAG_LPAR
jz .Lio_return
tpi 0
jz .Lio_return
mvc __PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
j .Lio_loop
.Lio_return:
LOCKDEP_SYS_EXIT
TRACE_IRQS_ON
.Lio_tif:
tm __TI_flags+7(%r12),_TIF_WORK
jnz .Lio_work # there is work to do (signals etc.)
tm __LC_CPU_FLAGS+7,_CIF_WORK
jnz .Lio_work
.Lio_restore:
lg %r14,__LC_VDSO_PER_CPU
lmg %r0,%r10,__PT_R0(%r11)
mvc __LC_RETURN_PSW(16),__PT_PSW(%r11)
stpt __LC_EXIT_TIMER
mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
lmg %r11,%r15,__PT_R11(%r11)
lpswe __LC_RETURN_PSW
.Lio_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 work
# 2) if we return to kernel code and kvm is enabled check if we need to
# modify the psw to leave SIE
# 3) 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.
#
.Lio_work:
tm __PT_PSW+1(%r11),0x01 # returning to user ?
jo .Lio_work_user # yes -> do resched & signal
#ifdef CONFIG_PREEMPT
# check for preemptive scheduling
icm %r0,15,__TI_precount(%r12)
jnz .Lio_restore # preemption is disabled
tm __TI_flags+7(%r12),_TIF_NEED_RESCHED
jno .Lio_restore
# switch to kernel stack
lg %r1,__PT_R15(%r11)
aghi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
la %r11,STACK_FRAME_OVERHEAD(%r1)
lgr %r15,%r1
# TRACE_IRQS_ON already done at .Lio_return, call
# TRACE_IRQS_OFF to keep things symmetrical
TRACE_IRQS_OFF
brasl %r14,preempt_schedule_irq
j .Lio_return
#else
j .Lio_restore
#endif
#
# Need to do work before returning to userspace, switch to kernel stack
#
.Lio_work_user:
lg %r1,__LC_KERNEL_STACK
mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
la %r11,STACK_FRAME_OVERHEAD(%r1)
lgr %r15,%r1
#
# One of the work bits is on. Find out which one.
#
.Lio_work_tif:
tm __LC_CPU_FLAGS+7,_CIF_MCCK_PENDING
jo .Lio_mcck_pending
tm __TI_flags+7(%r12),_TIF_NEED_RESCHED
jo .Lio_reschedule
tm __TI_flags+7(%r12),_TIF_SIGPENDING
jo .Lio_sigpending
tm __TI_flags+7(%r12),_TIF_NOTIFY_RESUME
jo .Lio_notify_resume
tm __LC_CPU_FLAGS+7,_CIF_ASCE
jo .Lio_uaccess
j .Lio_return # beware of critical section cleanup
#
# _CIF_MCCK_PENDING is set, call handler
#
.Lio_mcck_pending:
# TRACE_IRQS_ON already done at .Lio_return
brasl %r14,s390_handle_mcck # TIF bit will be cleared by handler
TRACE_IRQS_OFF
j .Lio_return
#
# _CIF_ASCE is set, load user space asce
#
.Lio_uaccess:
ni __LC_CPU_FLAGS+7,255-_CIF_ASCE
lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
j .Lio_return
#
# _TIF_NEED_RESCHED is set, call schedule
#
.Lio_reschedule:
# TRACE_IRQS_ON already done at .Lio_return
ssm __LC_SVC_NEW_PSW # reenable interrupts
brasl %r14,schedule # call scheduler
ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
TRACE_IRQS_OFF
j .Lio_return
#
# _TIF_SIGPENDING or is set, call do_signal
#
.Lio_sigpending:
# TRACE_IRQS_ON already done at .Lio_return
ssm __LC_SVC_NEW_PSW # reenable interrupts
lgr %r2,%r11 # pass pointer to pt_regs
brasl %r14,do_signal
ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
TRACE_IRQS_OFF
j .Lio_return
#
# _TIF_NOTIFY_RESUME or is set, call do_notify_resume
#
.Lio_notify_resume:
# TRACE_IRQS_ON already done at .Lio_return
ssm __LC_SVC_NEW_PSW # reenable interrupts
lgr %r2,%r11 # pass pointer to pt_regs
brasl %r14,do_notify_resume
ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
TRACE_IRQS_OFF
j .Lio_return
/*
* External interrupt handler routine
*/
ENTRY(ext_int_handler)
STCK __LC_INT_CLOCK
stpt __LC_ASYNC_ENTER_TIMER
stmg %r8,%r15,__LC_SAVE_AREA_ASYNC
lg %r10,__LC_LAST_BREAK
lg %r12,__LC_THREAD_INFO
larl %r13,system_call
lmg %r8,%r9,__LC_EXT_OLD_PSW
HANDLE_SIE_INTERCEPT %r14,3
SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT
tmhh %r8,0x0001 # interrupting from user ?
jz .Lext_skip
UPDATE_VTIME %r14,__LC_ASYNC_ENTER_TIMER
LAST_BREAK %r14
.Lext_skip:
stmg %r0,%r7,__PT_R0(%r11)
mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
stmg %r8,%r9,__PT_PSW(%r11)
lghi %r1,__LC_EXT_PARAMS2
mvc __PT_INT_CODE(4,%r11),__LC_EXT_CPU_ADDR
mvc __PT_INT_PARM(4,%r11),__LC_EXT_PARAMS
mvc __PT_INT_PARM_LONG(8,%r11),0(%r1)
xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
TRACE_IRQS_OFF
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
lgr %r2,%r11 # pass pointer to pt_regs
lghi %r3,EXT_INTERRUPT
brasl %r14,do_IRQ
j .Lio_return
/*
* Load idle PSW. The second "half" of this function is in .Lcleanup_idle.
*/
ENTRY(psw_idle)
stg %r3,__SF_EMPTY(%r15)
larl %r1,.Lpsw_idle_lpsw+4
stg %r1,__SF_EMPTY+8(%r15)
STCK __CLOCK_IDLE_ENTER(%r2)
stpt __TIMER_IDLE_ENTER(%r2)
.Lpsw_idle_lpsw:
lpswe __SF_EMPTY(%r15)
br %r14
.Lpsw_idle_end:
.L__critical_end:
/*
* Machine check handler routines
*/
ENTRY(mcck_int_handler)
STCK __LC_MCCK_CLOCK
la %r1,4095 # revalidate r1
spt __LC_CPU_TIMER_SAVE_AREA-4095(%r1) # revalidate cpu timer
lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# revalidate gprs
lg %r10,__LC_LAST_BREAK
lg %r12,__LC_THREAD_INFO
larl %r13,system_call
lmg %r8,%r9,__LC_MCK_OLD_PSW
HANDLE_SIE_INTERCEPT %r14,4
tm __LC_MCCK_CODE,0x80 # system damage?
jo .Lmcck_panic # yes -> rest of mcck code invalid
lghi %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 .Lmcck_panic # no -> skip cleanup critical
SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_PANIC_STACK,PAGE_SHIFT
tm %r8,0x0001 # interrupting from user ?
jz .Lmcck_skip
UPDATE_VTIME %r14,__LC_MCCK_ENTER_TIMER
LAST_BREAK %r14
.Lmcck_skip:
lghi %r14,__LC_GPREGS_SAVE_AREA+64
stmg %r0,%r7,__PT_R0(%r11)
mvc __PT_R8(64,%r11),0(%r14)
stmg %r8,%r9,__PT_PSW(%r11)
xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
lgr %r2,%r11 # pass pointer to pt_regs
brasl %r14,s390_do_machine_check
tm __PT_PSW+1(%r11),0x01 # returning to user ?
jno .Lmcck_return
lg %r1,__LC_KERNEL_STACK # switch to kernel stack
mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11)
xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1)
la %r11,STACK_FRAME_OVERHEAD(%r1)
lgr %r15,%r1
ssm __LC_PGM_NEW_PSW # turn dat on, keep irqs off
tm __LC_CPU_FLAGS+7,_CIF_MCCK_PENDING
jno .Lmcck_return
TRACE_IRQS_OFF
brasl %r14,s390_handle_mcck
TRACE_IRQS_ON
.Lmcck_return:
lg %r14,__LC_VDSO_PER_CPU
lmg %r0,%r10,__PT_R0(%r11)
mvc __LC_RETURN_MCCK_PSW(16),__PT_PSW(%r11) # move return PSW
tm __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
jno 0f
stpt __LC_EXIT_TIMER
mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
0: lmg %r11,%r15,__PT_R11(%r11)
lpswe __LC_RETURN_MCCK_PSW
.Lmcck_panic:
lg %r14,__LC_PANIC_STACK
slgr %r14,%r15
srag %r14,%r14,PAGE_SHIFT
jz 0f
lg %r15,__LC_PANIC_STACK
0: aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
j .Lmcck_skip
#
# PSW restart interrupt handler
#
ENTRY(restart_int_handler)
stg %r15,__LC_SAVE_AREA_RESTART
lg %r15,__LC_RESTART_STACK
aghi %r15,-__PT_SIZE # create pt_regs on stack
xc 0(__PT_SIZE,%r15),0(%r15)
stmg %r0,%r14,__PT_R0(%r15)
mvc __PT_R15(8,%r15),__LC_SAVE_AREA_RESTART
mvc __PT_PSW(16,%r15),__LC_RST_OLD_PSW # store restart old psw
aghi %r15,-STACK_FRAME_OVERHEAD # create stack frame on stack
xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15)
lg %r1,__LC_RESTART_FN # load fn, parm & source cpu
lg %r2,__LC_RESTART_DATA
lg %r3,__LC_RESTART_SOURCE
ltgr %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
llgh %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:
lg %r15,__LC_PANIC_STACK # change to panic stack
la %r11,STACK_FRAME_OVERHEAD(%r15)
stmg %r0,%r7,__PT_R0(%r11)
stmg %r8,%r9,__PT_PSW(%r11)
mvc __PT_R8(64,%r11),0(%r14)
stg %r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
lgr %r2,%r11 # pass pointer to pt_regs
jg kernel_stack_overflow
#endif
.align 8
.Lcleanup_table:
.quad system_call
.quad .Lsysc_do_svc
.quad .Lsysc_tif
.quad .Lsysc_restore
.quad .Lsysc_done
.quad .Lio_tif
.quad .Lio_restore
.quad .Lio_done
.quad psw_idle
.quad .Lpsw_idle_end
cleanup_critical:
clg %r9,BASED(.Lcleanup_table) # system_call
jl 0f
clg %r9,BASED(.Lcleanup_table+8) # .Lsysc_do_svc
jl .Lcleanup_system_call
clg %r9,BASED(.Lcleanup_table+16) # .Lsysc_tif
jl 0f
clg %r9,BASED(.Lcleanup_table+24) # .Lsysc_restore
jl .Lcleanup_sysc_tif
clg %r9,BASED(.Lcleanup_table+32) # .Lsysc_done
jl .Lcleanup_sysc_restore
clg %r9,BASED(.Lcleanup_table+40) # .Lio_tif
jl 0f
clg %r9,BASED(.Lcleanup_table+48) # .Lio_restore
jl .Lcleanup_io_tif
clg %r9,BASED(.Lcleanup_table+56) # .Lio_done
jl .Lcleanup_io_restore
clg %r9,BASED(.Lcleanup_table+64) # psw_idle
jl 0f
clg %r9,BASED(.Lcleanup_table+72) # .Lpsw_idle_end
jl .Lcleanup_idle
0: br %r14
.Lcleanup_system_call:
# check if stpt has been executed
clg %r9,BASED(.Lcleanup_system_call_insn)
jh 0f
mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
cghi %r11,__LC_SAVE_AREA_ASYNC
je 0f
mvc __LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER
0: # check if stmg has been executed
clg %r9,BASED(.Lcleanup_system_call_insn+8)
jh 0f
mvc __LC_SAVE_AREA_SYNC(64),0(%r11)
0: # check if base register setup + TIF bit load has been done
clg %r9,BASED(.Lcleanup_system_call_insn+16)
jhe 0f
# set up saved registers r10 and r12
stg %r10,16(%r11) # r10 last break
stg %r12,32(%r11) # r12 thread-info pointer
0: # check if the user time update has been done
clg %r9,BASED(.Lcleanup_system_call_insn+24)
jh 0f
lg %r15,__LC_EXIT_TIMER
slg %r15,__LC_SYNC_ENTER_TIMER
alg %r15,__LC_USER_TIMER
stg %r15,__LC_USER_TIMER
0: # check if the system time update has been done
clg %r9,BASED(.Lcleanup_system_call_insn+32)
jh 0f
lg %r15,__LC_LAST_UPDATE_TIMER
slg %r15,__LC_EXIT_TIMER
alg %r15,__LC_SYSTEM_TIMER
stg %r15,__LC_SYSTEM_TIMER
0: # update accounting time stamp
mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
# do LAST_BREAK
lg %r9,16(%r11)
srag %r9,%r9,23
jz 0f
mvc __TI_last_break(8,%r12),16(%r11)
0: # set up saved register r11
lg %r15,__LC_KERNEL_STACK
la %r9,STACK_FRAME_OVERHEAD(%r15)
stg %r9,24(%r11) # r11 pt_regs pointer
# fill pt_regs
mvc __PT_R8(64,%r9),__LC_SAVE_AREA_SYNC
stmg %r0,%r7,__PT_R0(%r9)
mvc __PT_PSW(16,%r9),__LC_SVC_OLD_PSW
mvc __PT_INT_CODE(4,%r9),__LC_SVC_ILC
xc __PT_FLAGS(8,%r9),__PT_FLAGS(%r9)
mvi __PT_FLAGS+7(%r9),_PIF_SYSCALL
# setup saved register r15
stg %r15,56(%r11) # r15 stack pointer
# set new psw address and exit
larl %r9,.Lsysc_do_svc
br %r14
.Lcleanup_system_call_insn:
.quad system_call
.quad .Lsysc_stmg
.quad .Lsysc_per
.quad .Lsysc_vtime+18
.quad .Lsysc_vtime+42
.Lcleanup_sysc_tif:
larl %r9,.Lsysc_tif
br %r14
.Lcleanup_sysc_restore:
clg %r9,BASED(.Lcleanup_sysc_restore_insn)
je 0f
lg %r9,24(%r11) # get saved pointer to pt_regs
mvc __LC_RETURN_PSW(16),__PT_PSW(%r9)
mvc 0(64,%r11),__PT_R8(%r9)
lmg %r0,%r7,__PT_R0(%r9)
0: lmg %r8,%r9,__LC_RETURN_PSW
br %r14
.Lcleanup_sysc_restore_insn:
.quad .Lsysc_done - 4
.Lcleanup_io_tif:
larl %r9,.Lio_tif
br %r14
.Lcleanup_io_restore:
clg %r9,BASED(.Lcleanup_io_restore_insn)
je 0f
lg %r9,24(%r11) # get saved r11 pointer to pt_regs
mvc __LC_RETURN_PSW(16),__PT_PSW(%r9)
mvc 0(64,%r11),__PT_R8(%r9)
lmg %r0,%r7,__PT_R0(%r9)
0: lmg %r8,%r9,__LC_RETURN_PSW
br %r14
.Lcleanup_io_restore_insn:
.quad .Lio_done - 4
.Lcleanup_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
cghi %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 & stpt have been executed
clg %r9,BASED(.Lcleanup_idle_insn)
jhe 1f
mvc __CLOCK_IDLE_ENTER(8,%r2),__CLOCK_IDLE_EXIT(%r2)
mvc __TIMER_IDLE_ENTER(8,%r2),__TIMER_IDLE_EXIT(%r2)
1: # account system time going idle
lg %r9,__LC_STEAL_TIMER
alg %r9,__CLOCK_IDLE_ENTER(%r2)
slg %r9,__LC_LAST_UPDATE_CLOCK
stg %r9,__LC_STEAL_TIMER
mvc __LC_LAST_UPDATE_CLOCK(8),__CLOCK_IDLE_EXIT(%r2)
lg %r9,__LC_SYSTEM_TIMER
alg %r9,__LC_LAST_UPDATE_TIMER
slg %r9,__TIMER_IDLE_ENTER(%r2)
stg %r9,__LC_SYSTEM_TIMER
mvc __LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2)
# prepare return psw
nihh %r8,0xfcfd # clear irq & wait state bits
lg %r9,48(%r11) # return from psw_idle
br %r14
.Lcleanup_idle_insn:
.quad .Lpsw_idle_lpsw
/*
* Integer constants
*/
.align 8
.Lcritical_start:
.quad .L__critical_start
.Lcritical_length:
.quad .L__critical_end - .L__critical_start
#if IS_ENABLED(CONFIG_KVM)
/*
* sie64a calling convention:
* %r2 pointer to sie control block
* %r3 guest register save area
*/
ENTRY(sie64a)
stmg %r6,%r14,__SF_GPRS(%r15) # save kernel registers
stg %r2,__SF_EMPTY(%r15) # save control block pointer
stg %r3,__SF_EMPTY+8(%r15) # save guest register save area
xc __SF_EMPTY+16(16,%r15),__SF_EMPTY+16(%r15) # host id & reason
lmg %r0,%r13,0(%r3) # load guest gprs 0-13
lg %r14,__LC_GMAP # get gmap pointer
ltgr %r14,%r14
jz .Lsie_gmap
lctlg %c1,%c1,__GMAP_ASCE(%r14) # load primary asce
.Lsie_gmap:
lg %r14,__SF_EMPTY(%r15) # get control block pointer
oi __SIE_PROG0C+3(%r14),1 # we are going into SIE now
tm __SIE_PROG20+3(%r14),1 # last exit...
jnz .Lsie_done
LPP __SF_EMPTY(%r15) # set guest id
sie 0(%r14)
.Lsie_done:
LPP __SF_EMPTY+16(%r15) # set host id
ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE
lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
# some program checks are suppressing. C code (e.g. do_protection_exception)
# will rewind the PSW by the ILC, which is 4 bytes in case of SIE. Other
# instructions between sie64a and .Lsie_done should not cause program
# interrupts. So lets use a nop (47 00 00 00) as a landing pad.
# See also HANDLE_SIE_INTERCEPT
.Lrewind_pad:
nop 0
.globl sie_exit
sie_exit:
lg %r14,__SF_EMPTY+8(%r15) # load guest register save area
stmg %r0,%r13,0(%r14) # save guest gprs 0-13
lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers
lg %r2,__SF_EMPTY+24(%r15) # return exit reason code
br %r14
.Lsie_fault:
lghi %r14,-EFAULT
stg %r14,__SF_EMPTY+24(%r15) # set exit reason code
j sie_exit
.align 8
.Lsie_critical:
.quad .Lsie_gmap
.Lsie_critical_length:
.quad .Lsie_done - .Lsie_gmap
EX_TABLE(.Lrewind_pad,.Lsie_fault)
EX_TABLE(sie_exit,.Lsie_fault)
#endif
.section .rodata, "a"
#define SYSCALL(esa,esame,emu) .long esame
.globl sys_call_table
sys_call_table:
#include "syscalls.S"
#undef SYSCALL
#ifdef CONFIG_COMPAT
#define SYSCALL(esa,esame,emu) .long emu
.globl sys_call_table_emu
sys_call_table_emu:
#include "syscalls.S"
#undef SYSCALL
#endif
