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kernel-fxtec-pro1x/arch/s390/kernel/entry64.S
Heiko Carstens f2db2e6cb3 [S390] pfault: cpu hotplug vs missing completion interrupts 
On cpu hot remove a PFAULT CANCEL command is sent to the hypervisor
which in turn will cancel all outstanding pfault requests that have
been issued on that cpu (the same happens with a SIGP cpu reset).

The result is that we end up with uninterruptible processes where
the interrupt that would wake up these processes never arrives.

In order to solve this all processes which wait for a pfault
completion interrupt get woken up after a cpu hot remove. The worst
case that could happen is that they fault again and in turn need to
wait again.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-05-23 10:24:29 +02:00

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/*
* arch/s390/kernel/entry64.S
* S390 low-level entry points.
*
* Copyright (C) IBM Corp. 1999,2010
* 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/linkage.h>
#include <linux/init.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>
/*
* 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_PER_TRAP )
_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
_TIF_MCCK_PENDING)
_TIF_SYSCALL = (_TIF_SYSCALL_TRACE>>8 | _TIF_SYSCALL_AUDIT>>8 | \
_TIF_SECCOMP>>8 | _TIF_SYSCALL_TRACEPOINT>>8)
#define BASED(name) name-system_call(%r13)
.macro HANDLE_SIE_INTERCEPT
#if defined(CONFIG_KVM) || defined(CONFIG_KVM_MODULE)
lg %r3,__LC_SIE_HOOK
ltgr %r3,%r3
jz 0f
basr %r14,%r3
0:
#endif
.endm
#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
#else
#define TRACE_IRQS_ON
#define TRACE_IRQS_OFF
#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_SVC psworg,savearea
stmg %r11,%r15,\savearea
lg %r15,__LC_KERNEL_STACK # problem state -> load ksp
aghi %r15,-SP_SIZE # make room for registers & psw
lg %r11,__LC_LAST_BREAK
.endm
.macro SAVE_ALL_PGM psworg,savearea
stmg %r11,%r15,\savearea
tm \psworg+1,0x01 # test problem state bit
#ifdef CONFIG_CHECK_STACK
jnz 1f
tml %r15,STACK_SIZE - CONFIG_STACK_GUARD
jnz 2f
la %r12,\psworg
j stack_overflow
#else
jz 2f
#endif
1: lg %r15,__LC_KERNEL_STACK # problem state -> load ksp
2: aghi %r15,-SP_SIZE # make room for registers & psw
larl %r13,system_call
lg %r11,__LC_LAST_BREAK
.endm
.macro SAVE_ALL_ASYNC psworg,savearea
stmg %r11,%r15,\savearea
larl %r13,system_call
lg %r11,__LC_LAST_BREAK
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
tm 1(%r12),0x01 # retest problem state after cleanup
jnz 1f
0: lg %r14,__LC_ASYNC_STACK # are we already on the async. stack ?
slgr %r14,%r15
srag %r14,%r14,STACK_SHIFT
#ifdef CONFIG_CHECK_STACK
jnz 1f
tml %r15,STACK_SIZE - CONFIG_STACK_GUARD
jnz 2f
j stack_overflow
#else
jz 2f
#endif
1: lg %r15,__LC_ASYNC_STACK # load async stack
2: aghi %r15,-SP_SIZE # make room for registers & psw
.endm
.macro CREATE_STACK_FRAME savearea
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
stg %r2,SP_ORIG_R2(%r15) # store original content of gpr 2
mvc SP_R11(40,%r15),\savearea # move %r11-%r15 to stack
stmg %r0,%r10,SP_R0(%r15) # store gprs %r0-%r10 to kernel stack
.endm
.macro RESTORE_ALL psworg,sync
mvc \psworg(16),SP_PSW(%r15) # move user PSW to lowcore
.if !\sync
ni \psworg+1,0xfd # clear wait state bit
.endif
lg %r14,__LC_VDSO_PER_CPU
lmg %r0,%r13,SP_R0(%r15) # load gprs 0-13 of user
stpt __LC_EXIT_TIMER
mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
lmg %r14,%r15,SP_R14(%r15) # load grps 14-15 of user
lpswe \psworg # back to caller
.endm
.macro LAST_BREAK
srag %r10,%r11,23
jz 0f
stg %r11,__TI_last_break(%r12)
0:
.endm
.macro REENABLE_IRQS
mvc __SF_EMPTY(1,%r15),SP_PSW(%r15)
ni __SF_EMPTY(%r15),0xbf
ssm __SF_EMPTY(%r15)
.endm
.section .kprobes.text, "ax"
/*
* Scheduler resume function, called by switch_to
* gpr2 = (task_struct *) prev
* gpr3 = (task_struct *) next
* Returns:
* gpr2 = prev
*/
.globl __switch_to
__switch_to:
lg %r4,__THREAD_info(%r2) # get thread_info of prev
lg %r5,__THREAD_info(%r3) # get thread_info of next
tm __TI_flags+7(%r4),_TIF_MCCK_PENDING # machine check pending?
jz 0f
ni __TI_flags+7(%r4),255-_TIF_MCCK_PENDING # clear flag in prev
oi __TI_flags+7(%r5),_TIF_MCCK_PENDING # set it in next
0: stmg %r6,%r15,__SF_GPRS(%r15) # store gprs of prev task
stg %r15,__THREAD_ksp(%r2) # store kernel stack of prev
lg %r15,__THREAD_ksp(%r3) # load kernel stack of next
lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4
lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task
stg %r3,__LC_CURRENT # store task struct of next
mvc __LC_CURRENT_PID+4(4,%r0),__TASK_pid(%r3) # store pid of next
stg %r5,__LC_THREAD_INFO # store thread info of next
aghi %r5,STACK_SIZE # end of kernel stack of next
stg %r5,__LC_KERNEL_STACK # store end of kernel stack
br %r14
__critical_start:
/*
* SVC interrupt handler routine. System calls are synchronous events and
* are executed with interrupts enabled.
*/
.globl system_call
system_call:
stpt __LC_SYNC_ENTER_TIMER
sysc_saveall:
SAVE_ALL_SVC __LC_SVC_OLD_PSW,__LC_SAVE_AREA
CREATE_STACK_FRAME __LC_SAVE_AREA
mvc SP_PSW(16,%r15),__LC_SVC_OLD_PSW
mvc SP_ILC(4,%r15),__LC_SVC_ILC
lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
sysc_vtime:
UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
sysc_stime:
UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
sysc_update:
mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
LAST_BREAK
sysc_do_svc:
llgh %r7,SP_SVCNR(%r15)
slag %r7,%r7,2 # shift and test for svc 0
jnz sysc_nr_ok
# svc 0: system call number in %r1
llgfr %r1,%r1 # clear high word in r1
cghi %r1,NR_syscalls
jnl sysc_nr_ok
sth %r1,SP_SVCNR(%r15)
slag %r7,%r1,2 # shift and test for svc 0
sysc_nr_ok:
larl %r10,sys_call_table
#ifdef CONFIG_COMPAT
tm __TI_flags+5(%r12),(_TIF_31BIT>>16) # running in 31 bit mode ?
jno sysc_noemu
larl %r10,sys_call_table_emu # use 31 bit emulation system calls
sysc_noemu:
#endif
tm __TI_flags+6(%r12),_TIF_SYSCALL
mvc SP_ARGS(8,%r15),SP_R7(%r15)
lgf %r8,0(%r7,%r10) # load address of system call routine
jnz sysc_tracesys
basr %r14,%r8 # call sys_xxxx
stg %r2,SP_R2(%r15) # store return value (change R2 on stack)
sysc_return:
LOCKDEP_SYS_EXIT
sysc_tif:
tm __TI_flags+7(%r12),_TIF_WORK_SVC
jnz sysc_work # there is work to do (signals etc.)
sysc_restore:
RESTORE_ALL __LC_RETURN_PSW,1
sysc_done:
#
# There is work to do, but first we need to check if we return to userspace.
#
sysc_work:
tm SP_PSW+1(%r15),0x01 # returning to user ?
jno sysc_restore
#
# One of the work bits is on. Find out which one.
#
sysc_work_tif:
tm __TI_flags+7(%r12),_TIF_MCCK_PENDING
jo sysc_mcck_pending
tm __TI_flags+7(%r12),_TIF_NEED_RESCHED
jo sysc_reschedule
tm __TI_flags+7(%r12),_TIF_SIGPENDING
jo sysc_sigpending
tm __TI_flags+7(%r12),_TIF_NOTIFY_RESUME
jo sysc_notify_resume
tm __TI_flags+7(%r12),_TIF_RESTART_SVC
jo sysc_restart
tm __TI_flags+7(%r12),_TIF_PER_TRAP
jo sysc_singlestep
j sysc_return # beware of critical section cleanup
#
# _TIF_NEED_RESCHED is set, call schedule
#
sysc_reschedule:
larl %r14,sysc_return
jg schedule # return point is sysc_return
#
# _TIF_MCCK_PENDING is set, call handler
#
sysc_mcck_pending:
larl %r14,sysc_return
jg s390_handle_mcck # TIF bit will be cleared by handler
#
# _TIF_SIGPENDING is set, call do_signal
#
sysc_sigpending:
ni __TI_flags+7(%r12),255-_TIF_PER_TRAP # clear TIF_PER_TRAP
la %r2,SP_PTREGS(%r15) # load pt_regs
brasl %r14,do_signal # call do_signal
tm __TI_flags+7(%r12),_TIF_RESTART_SVC
jo sysc_restart
tm __TI_flags+7(%r12),_TIF_PER_TRAP
jo sysc_singlestep
j sysc_return
#
# _TIF_NOTIFY_RESUME is set, call do_notify_resume
#
sysc_notify_resume:
la %r2,SP_PTREGS(%r15) # load pt_regs
larl %r14,sysc_return
jg do_notify_resume # call do_notify_resume
#
# _TIF_RESTART_SVC is set, set up registers and restart svc
#
sysc_restart:
ni __TI_flags+7(%r12),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC
lg %r7,SP_R2(%r15) # load new svc number
mvc SP_R2(8,%r15),SP_ORIG_R2(%r15) # restore first argument
lmg %r2,%r6,SP_R2(%r15) # load svc arguments
sth %r7,SP_SVCNR(%r15)
slag %r7,%r7,2
j sysc_nr_ok # restart svc
#
# _TIF_PER_TRAP is set, call do_per_trap
#
sysc_singlestep:
ni __TI_flags+7(%r12),255-_TIF_PER_TRAP # clear TIF_PER_TRAP
xc SP_SVCNR(2,%r15),SP_SVCNR(%r15) # clear svc number
la %r2,SP_PTREGS(%r15) # address of register-save area
larl %r14,sysc_return # load adr. of system return
jg do_per_trap
#
# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
# and after the system call
#
sysc_tracesys:
la %r2,SP_PTREGS(%r15) # load pt_regs
la %r3,0
llgh %r0,SP_SVCNR(%r15)
stg %r0,SP_R2(%r15)
brasl %r14,do_syscall_trace_enter
lghi %r0,NR_syscalls
clgr %r0,%r2
jnh sysc_tracenogo
sllg %r7,%r2,2 # svc number *4
lgf %r8,0(%r7,%r10)
sysc_tracego:
lmg %r3,%r6,SP_R3(%r15)
mvc SP_ARGS(8,%r15),SP_R7(%r15)
lg %r2,SP_ORIG_R2(%r15)
basr %r14,%r8 # call sys_xxx
stg %r2,SP_R2(%r15) # store return value
sysc_tracenogo:
tm __TI_flags+6(%r12),_TIF_SYSCALL
jz sysc_return
la %r2,SP_PTREGS(%r15) # load pt_regs
larl %r14,sysc_return # return point is sysc_return
jg do_syscall_trace_exit
#
# a new process exits the kernel with ret_from_fork
#
.globl ret_from_fork
ret_from_fork:
lg %r13,__LC_SVC_NEW_PSW+8
lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
tm SP_PSW+1(%r15),0x01 # forking a kernel thread ?
jo 0f
stg %r15,SP_R15(%r15) # store stack pointer for new kthread
0: brasl %r14,schedule_tail
TRACE_IRQS_ON
stosm 24(%r15),0x03 # reenable interrupts
j sysc_tracenogo
#
# kernel_execve function needs to deal with pt_regs that is not
# at the usual place
#
.globl kernel_execve
kernel_execve:
stmg %r12,%r15,96(%r15)
lgr %r14,%r15
aghi %r15,-SP_SIZE
stg %r14,__SF_BACKCHAIN(%r15)
la %r12,SP_PTREGS(%r15)
xc 0(__PT_SIZE,%r12),0(%r12)
lgr %r5,%r12
brasl %r14,do_execve
ltgfr %r2,%r2
je 0f
aghi %r15,SP_SIZE
lmg %r12,%r15,96(%r15)
br %r14
# execve succeeded.
0: stnsm __SF_EMPTY(%r15),0xfc # disable interrupts
lg %r15,__LC_KERNEL_STACK # load ksp
aghi %r15,-SP_SIZE # make room for registers & psw
lg %r13,__LC_SVC_NEW_PSW+8
mvc SP_PTREGS(__PT_SIZE,%r15),0(%r12) # copy pt_regs
lg %r12,__LC_THREAD_INFO
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
brasl %r14,execve_tail
j sysc_return
/*
* Program check handler routine
*/
.globl pgm_check_handler
pgm_check_handler:
/*
* First we need to check for a special case:
* Single stepping an instruction that disables the PER event mask will
* cause a PER event AFTER the mask has been set. Example: SVC or LPSW.
* For a single stepped SVC the program check handler gets control after
* the SVC new PSW has been loaded. But we want to execute the SVC first and
* then handle the PER event. Therefore we update the SVC old PSW to point
* to the pgm_check_handler and branch to the SVC handler after we checked
* if we have to load the kernel stack register.
* For every other possible cause for PER event without the PER mask set
* we just ignore the PER event (FIXME: is there anything we have to do
* for LPSW?).
*/
stpt __LC_SYNC_ENTER_TIMER
tm __LC_PGM_INT_CODE+1,0x80 # check whether we got a per exception
jnz pgm_per # got per exception -> special case
SAVE_ALL_PGM __LC_PGM_OLD_PSW,__LC_SAVE_AREA
CREATE_STACK_FRAME __LC_SAVE_AREA
xc SP_ILC(4,%r15),SP_ILC(%r15)
mvc SP_PSW(16,%r15),__LC_PGM_OLD_PSW
lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
tm SP_PSW+1(%r15),0x01 # interrupting from user ?
jz pgm_no_vtime
UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
LAST_BREAK
pgm_no_vtime:
HANDLE_SIE_INTERCEPT
stg %r11,SP_ARGS(%r15)
lgf %r3,__LC_PGM_ILC # load program interruption code
lg %r4,__LC_TRANS_EXC_CODE
REENABLE_IRQS
lghi %r8,0x7f
ngr %r8,%r3
sll %r8,3
larl %r1,pgm_check_table
lg %r1,0(%r8,%r1) # load address of handler routine
la %r2,SP_PTREGS(%r15) # address of register-save area
basr %r14,%r1 # branch to interrupt-handler
pgm_exit:
j sysc_return
#
# handle per exception
#
pgm_per:
tm __LC_PGM_OLD_PSW,0x40 # test if per event recording is on
jnz pgm_per_std # ok, normal per event from user space
# ok its one of the special cases, now we need to find out which one
clc __LC_PGM_OLD_PSW(16),__LC_SVC_NEW_PSW
je pgm_svcper
# no interesting special case, ignore PER event
lpswe __LC_PGM_OLD_PSW
#
# Normal per exception
#
pgm_per_std:
SAVE_ALL_PGM __LC_PGM_OLD_PSW,__LC_SAVE_AREA
CREATE_STACK_FRAME __LC_SAVE_AREA
mvc SP_PSW(16,%r15),__LC_PGM_OLD_PSW
lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
tm SP_PSW+1(%r15),0x01 # interrupting from user ?
jz pgm_no_vtime2
UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
LAST_BREAK
pgm_no_vtime2:
HANDLE_SIE_INTERCEPT
lg %r1,__TI_task(%r12)
tm SP_PSW+1(%r15),0x01 # kernel per event ?
jz kernel_per
mvc __THREAD_per_cause(2,%r1),__LC_PER_CAUSE
mvc __THREAD_per_address(8,%r1),__LC_PER_ADDRESS
mvc __THREAD_per_paid(1,%r1),__LC_PER_PAID
oi __TI_flags+7(%r12),_TIF_PER_TRAP # set TIF_PER_TRAP
lgf %r3,__LC_PGM_ILC # load program interruption code
lg %r4,__LC_TRANS_EXC_CODE
REENABLE_IRQS
lghi %r8,0x7f
ngr %r8,%r3 # clear per-event-bit and ilc
je pgm_exit2
sll %r8,3
larl %r1,pgm_check_table
lg %r1,0(%r8,%r1) # load address of handler routine
la %r2,SP_PTREGS(%r15) # address of register-save area
basr %r14,%r1 # branch to interrupt-handler
pgm_exit2:
j sysc_return
#
# it was a single stepped SVC that is causing all the trouble
#
pgm_svcper:
SAVE_ALL_PGM __LC_SVC_OLD_PSW,__LC_SAVE_AREA
CREATE_STACK_FRAME __LC_SAVE_AREA
mvc SP_PSW(16,%r15),__LC_SVC_OLD_PSW
mvc SP_ILC(4,%r15),__LC_SVC_ILC
lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
LAST_BREAK
lg %r8,__TI_task(%r12)
mvc __THREAD_per_cause(2,%r8),__LC_PER_CAUSE
mvc __THREAD_per_address(8,%r8),__LC_PER_ADDRESS
mvc __THREAD_per_paid(1,%r8),__LC_PER_PAID
oi __TI_flags+7(%r12),_TIF_PER_TRAP # set TIF_PER_TRAP
stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
lmg %r2,%r6,SP_R2(%r15) # load svc arguments
j sysc_do_svc
#
# per was called from kernel, must be kprobes
#
kernel_per:
REENABLE_IRQS
xc SP_SVCNR(2,%r15),SP_SVCNR(%r15) # clear svc number
la %r2,SP_PTREGS(%r15) # address of register-save area
brasl %r14,do_per_trap
j pgm_exit
/*
* IO interrupt handler routine
*/
.globl io_int_handler
io_int_handler:
stck __LC_INT_CLOCK
stpt __LC_ASYNC_ENTER_TIMER
SAVE_ALL_ASYNC __LC_IO_OLD_PSW,__LC_SAVE_AREA+40
CREATE_STACK_FRAME __LC_SAVE_AREA+40
mvc SP_PSW(16,%r15),0(%r12) # move user PSW to stack
lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
tm SP_PSW+1(%r15),0x01 # interrupting from user ?
jz io_no_vtime
UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER
UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
mvc __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
LAST_BREAK
io_no_vtime:
HANDLE_SIE_INTERCEPT
TRACE_IRQS_OFF
la %r2,SP_PTREGS(%r15) # address of register-save area
brasl %r14,do_IRQ # call standard irq handler
io_return:
LOCKDEP_SYS_EXIT
TRACE_IRQS_ON
io_tif:
tm __TI_flags+7(%r12),_TIF_WORK_INT
jnz io_work # there is work to do (signals etc.)
io_restore:
RESTORE_ALL __LC_RETURN_PSW,0
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 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.
#
io_work:
tm SP_PSW+1(%r15),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 is disabled
tm __TI_flags+7(%r12),_TIF_NEED_RESCHED
jno io_restore
# switch to kernel stack
lg %r1,SP_R15(%r15)
aghi %r1,-SP_SIZE
mvc SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) # clear back chain
lgr %r15,%r1
# TRACE_IRQS_ON already done at io_return, call
# TRACE_IRQS_OFF to keep things symmetrical
TRACE_IRQS_OFF
brasl %r14,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:
lg %r1,__LC_KERNEL_STACK
aghi %r1,-SP_SIZE
mvc SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) # clear back chain
lgr %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+7(%r12),_TIF_MCCK_PENDING
jo io_mcck_pending
tm __TI_flags+7(%r12),_TIF_NEED_RESCHED
jo io_reschedule
tm __TI_flags+7(%r12),_TIF_SIGPENDING
jo io_sigpending
tm __TI_flags+7(%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
brasl %r14,s390_handle_mcck # 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
stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
brasl %r14,schedule # call scheduler
stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts
TRACE_IRQS_OFF
j io_return
#
# _TIF_SIGPENDING or is set, call do_signal
#
io_sigpending:
# TRACE_IRQS_ON already done at io_return
stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
la %r2,SP_PTREGS(%r15) # load pt_regs
brasl %r14,do_signal # call do_signal
stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts
TRACE_IRQS_OFF
j io_return
#
# _TIF_NOTIFY_RESUME or is set, call do_notify_resume
#
io_notify_resume:
# TRACE_IRQS_ON already done at io_return
stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
la %r2,SP_PTREGS(%r15) # load pt_regs
brasl %r14,do_notify_resume # call do_notify_resume
stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts
TRACE_IRQS_OFF
j io_return
/*
* External interrupt handler routine
*/
.globl ext_int_handler
ext_int_handler:
stck __LC_INT_CLOCK
stpt __LC_ASYNC_ENTER_TIMER
SAVE_ALL_ASYNC __LC_EXT_OLD_PSW,__LC_SAVE_AREA+40
CREATE_STACK_FRAME __LC_SAVE_AREA+40
mvc SP_PSW(16,%r15),0(%r12) # move user PSW to stack
lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
tm SP_PSW+1(%r15),0x01 # interrupting from user ?
jz ext_no_vtime
UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER
UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
mvc __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
LAST_BREAK
ext_no_vtime:
HANDLE_SIE_INTERCEPT
TRACE_IRQS_OFF
lghi %r1,4096
la %r2,SP_PTREGS(%r15) # address of register-save area
llgf %r3,__LC_CPU_ADDRESS # get cpu address + interruption code
llgf %r4,__LC_EXT_PARAMS # get external parameter
lg %r5,__LC_EXT_PARAMS2-4096(%r1) # get 64 bit external parameter
brasl %r14,do_extint
j io_return
__critical_end:
/*
* Machine check handler routines
*/
.globl mcck_int_handler
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
stmg %r11,%r15,__LC_SAVE_AREA+80
larl %r13,system_call
lg %r11,__LC_LAST_BREAK
la %r12,__LC_MCK_OLD_PSW
tm __LC_MCCK_CODE,0x80 # system damage?
jo mcck_int_main # yes -> rest of mcck code invalid
la %r14,4095
mvc __LC_MCCK_ENTER_TIMER(8),__LC_CPU_TIMER_SAVE_AREA-4095(%r14)
tm __LC_MCCK_CODE+5,0x02 # stored cpu timer value valid?
jo 1f
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 0f
la %r14,__LC_EXIT_TIMER
0: clc 0(8,%r14),__LC_LAST_UPDATE_TIMER
jl 0f
la %r14,__LC_LAST_UPDATE_TIMER
0: spt 0(%r14)
mvc __LC_MCCK_ENTER_TIMER(8),0(%r14)
1: tm __LC_MCCK_CODE+2,0x09 # mwp + ia of old psw valid?
jno mcck_int_main # no -> skip cleanup critical
tm __LC_MCK_OLD_PSW+1,0x01 # test problem state bit
jnz mcck_int_main # from user -> load kernel stack
clc __LC_MCK_OLD_PSW+8(8),BASED(.Lcritical_end)
jhe mcck_int_main
clc __LC_MCK_OLD_PSW+8(8),BASED(.Lcritical_start)
jl mcck_int_main
brasl %r14,cleanup_critical
mcck_int_main:
lg %r14,__LC_PANIC_STACK # are we already on the panic stack?
slgr %r14,%r15
srag %r14,%r14,PAGE_SHIFT
jz 0f
lg %r15,__LC_PANIC_STACK # load panic stack
0: aghi %r15,-SP_SIZE # make room for registers & psw
CREATE_STACK_FRAME __LC_SAVE_AREA+80
mvc SP_PSW(16,%r15),0(%r12)
lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct
tm __LC_MCCK_CODE+2,0x08 # mwp of old psw valid?
jno mcck_no_vtime # no -> no timer update
tm SP_PSW+1(%r15),0x01 # interrupting from user ?
jz mcck_no_vtime
UPDATE_VTIME __LC_EXIT_TIMER,__LC_MCCK_ENTER_TIMER,__LC_USER_TIMER
UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
mvc __LC_LAST_UPDATE_TIMER(8),__LC_MCCK_ENTER_TIMER
LAST_BREAK
mcck_no_vtime:
la %r2,SP_PTREGS(%r15) # load pt_regs
brasl %r14,s390_do_machine_check
tm SP_PSW+1(%r15),0x01 # returning to user ?
jno mcck_return
lg %r1,__LC_KERNEL_STACK # switch to kernel stack
aghi %r1,-SP_SIZE
mvc SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) # clear back chain
lgr %r15,%r1
stosm __SF_EMPTY(%r15),0x04 # turn dat on
tm __TI_flags+7(%r12),_TIF_MCCK_PENDING
jno mcck_return
HANDLE_SIE_INTERCEPT
TRACE_IRQS_OFF
brasl %r14,s390_handle_mcck
TRACE_IRQS_ON
mcck_return:
mvc __LC_RETURN_MCCK_PSW(16),SP_PSW(%r15) # move return PSW
ni __LC_RETURN_MCCK_PSW+1,0xfd # clear wait state bit
lmg %r0,%r15,SP_R0(%r15) # load gprs 0-15
tm __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
jno 0f
stpt __LC_EXIT_TIMER
0: lpswe __LC_RETURN_MCCK_PSW # back to caller
mcck_done:
/*
* Restart interruption handler, kick starter for additional CPUs
*/
#ifdef CONFIG_SMP
__CPUINIT
.globl restart_int_handler
restart_int_handler:
basr %r1,0
restart_base:
spt restart_vtime-restart_base(%r1)
stck __LC_LAST_UPDATE_CLOCK
mvc __LC_LAST_UPDATE_TIMER(8),restart_vtime-restart_base(%r1)
mvc __LC_EXIT_TIMER(8),restart_vtime-restart_base(%r1)
lg %r15,__LC_SAVE_AREA+120 # load ksp
lghi %r10,__LC_CREGS_SAVE_AREA
lctlg %c0,%c15,0(%r10) # get new ctl regs
lghi %r10,__LC_AREGS_SAVE_AREA
lam %a0,%a15,0(%r10)
lmg %r6,%r15,__SF_GPRS(%r15) # load registers from clone
lg %r1,__LC_THREAD_INFO
mvc __LC_USER_TIMER(8),__TI_user_timer(%r1)
mvc __LC_SYSTEM_TIMER(8),__TI_system_timer(%r1)
xc __LC_STEAL_TIMER(8),__LC_STEAL_TIMER
stosm __SF_EMPTY(%r15),0x04 # now we can turn dat on
brasl %r14,start_secondary
.align 8
restart_vtime:
.long 0x7fffffff,0xffffffff
.previous
#else
/*
* If we do not run with SMP enabled, let the new CPU crash ...
*/
.globl restart_int_handler
restart_int_handler:
basr %r1,0
restart_base:
lpswe restart_crash-restart_base(%r1)
.align 8
restart_crash:
.long 0x000a0000,0x00000000,0x00000000,0x00000000
restart_go:
#endif
.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
aghi %r15,-SP_SIZE
mvc SP_PSW(16,%r15),0(%r12) # move user PSW to stack
stmg %r0,%r10,SP_R0(%r15) # store gprs %r0-%r10 to kernel stack
la %r1,__LC_SAVE_AREA
chi %r12,__LC_SVC_OLD_PSW
je 0f
chi %r12,__LC_PGM_OLD_PSW
je 0f
la %r1,__LC_SAVE_AREA+40
0: mvc SP_R11(40,%r15),0(%r1) # move %r11-%r15 to stack
mvc SP_ARGS(8,%r15),__LC_LAST_BREAK
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) # clear back chain
la %r2,SP_PTREGS(%r15) # load pt_regs
jg kernel_stack_overflow
#endif
cleanup_table_system_call:
.quad system_call, sysc_do_svc
cleanup_table_sysc_tif:
.quad sysc_tif, sysc_restore
cleanup_table_sysc_restore:
.quad sysc_restore, sysc_done
cleanup_table_io_tif:
.quad io_tif, io_restore
cleanup_table_io_restore:
.quad io_restore, io_done
cleanup_critical:
clc 8(8,%r12),BASED(cleanup_table_system_call)
jl 0f
clc 8(8,%r12),BASED(cleanup_table_system_call+8)
jl cleanup_system_call
0:
clc 8(8,%r12),BASED(cleanup_table_sysc_tif)
jl 0f
clc 8(8,%r12),BASED(cleanup_table_sysc_tif+8)
jl cleanup_sysc_tif
0:
clc 8(8,%r12),BASED(cleanup_table_sysc_restore)
jl 0f
clc 8(8,%r12),BASED(cleanup_table_sysc_restore+8)
jl cleanup_sysc_restore
0:
clc 8(8,%r12),BASED(cleanup_table_io_tif)
jl 0f
clc 8(8,%r12),BASED(cleanup_table_io_tif+8)
jl cleanup_io_tif
0:
clc 8(8,%r12),BASED(cleanup_table_io_restore)
jl 0f
clc 8(8,%r12),BASED(cleanup_table_io_restore+8)
jl cleanup_io_restore
0:
br %r14
cleanup_system_call:
mvc __LC_RETURN_PSW(16),0(%r12)
clc __LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+8)
jh 0f
mvc __LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER
cghi %r12,__LC_MCK_OLD_PSW
je 0f
mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
0: cghi %r12,__LC_MCK_OLD_PSW
la %r12,__LC_SAVE_AREA+80
je 0f
la %r12,__LC_SAVE_AREA+40
0: clc __LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+16)
jhe cleanup_vtime
clc __LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn)
jh 0f
mvc __LC_SAVE_AREA(40),0(%r12)
0: lg %r15,__LC_KERNEL_STACK # problem state -> load ksp
aghi %r15,-SP_SIZE # make room for registers & psw
stg %r15,32(%r12)
stg %r11,0(%r12)
CREATE_STACK_FRAME __LC_SAVE_AREA
mvc SP_PSW(16,%r15),__LC_SVC_OLD_PSW
mvc SP_ILC(4,%r15),__LC_SVC_ILC
mvc 8(8,%r12),__LC_THREAD_INFO
cleanup_vtime:
clc __LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+24)
jhe cleanup_stime
UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
cleanup_stime:
clc __LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+32)
jh cleanup_update
UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
cleanup_update:
mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
srag %r12,%r11,23
lg %r12,__LC_THREAD_INFO
jz 0f
stg %r11,__TI_last_break(%r12)
0: mvc __LC_RETURN_PSW+8(8),BASED(cleanup_table_system_call+8)
la %r12,__LC_RETURN_PSW
br %r14
cleanup_system_call_insn:
.quad sysc_saveall
.quad system_call
.quad sysc_vtime
.quad sysc_stime
.quad sysc_update
cleanup_sysc_tif:
mvc __LC_RETURN_PSW(8),0(%r12)
mvc __LC_RETURN_PSW+8(8),BASED(cleanup_table_sysc_tif)
la %r12,__LC_RETURN_PSW
br %r14
cleanup_sysc_restore:
clc 8(8,%r12),BASED(cleanup_sysc_restore_insn)
je 2f
clc 8(8,%r12),BASED(cleanup_sysc_restore_insn+8)
jhe 0f
mvc __LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER
cghi %r12,__LC_MCK_OLD_PSW
je 0f
mvc __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER
0: mvc __LC_RETURN_PSW(16),SP_PSW(%r15)
cghi %r12,__LC_MCK_OLD_PSW
la %r12,__LC_SAVE_AREA+80
je 1f
la %r12,__LC_SAVE_AREA+40
1: mvc 0(40,%r12),SP_R11(%r15)
lmg %r0,%r10,SP_R0(%r15)
lg %r15,SP_R15(%r15)
2: la %r12,__LC_RETURN_PSW
br %r14
cleanup_sysc_restore_insn:
.quad sysc_done - 4
.quad sysc_done - 16
cleanup_io_tif:
mvc __LC_RETURN_PSW(8),0(%r12)
mvc __LC_RETURN_PSW+8(8),BASED(cleanup_table_io_tif)
la %r12,__LC_RETURN_PSW
br %r14
cleanup_io_restore:
clc 8(8,%r12),BASED(cleanup_io_restore_insn)
je 1f
clc 8(8,%r12),BASED(cleanup_io_restore_insn+8)
jhe 0f
mvc __LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER
0: mvc __LC_RETURN_PSW(16),SP_PSW(%r15)
mvc __LC_SAVE_AREA+80(40),SP_R11(%r15)
lmg %r0,%r10,SP_R0(%r15)
lg %r15,SP_R15(%r15)
1: la %r12,__LC_RETURN_PSW
br %r14
cleanup_io_restore_insn:
.quad io_done - 4
.quad io_done - 16
/*
* Integer constants
*/
.align 4
.Lcritical_start:
.quad __critical_start
.Lcritical_end:
.quad __critical_end
.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
sys_call_table_emu:
#include "syscalls.S"
#undef SYSCALL
#endif
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