/*
* arch/s390/kernel/entry.S
* S390 low-level entry points.
*
* Copyright (C) IBM Corp. 1999,2006
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
* Hartmut Penner (hp@de.ibm.com),
* Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
* Heiko Carstens <heiko.carstens@de.ibm.com>
*/
#include <linux/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>
/*
* 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 + 4
SP_R2 = STACK_FRAME_OVERHEAD + __PT_GPRS + 8
SP_R3 = STACK_FRAME_OVERHEAD + __PT_GPRS + 12
SP_R4 = STACK_FRAME_OVERHEAD + __PT_GPRS + 16
SP_R5 = STACK_FRAME_OVERHEAD + __PT_GPRS + 20
SP_R6 = STACK_FRAME_OVERHEAD + __PT_GPRS + 24
SP_R7 = STACK_FRAME_OVERHEAD + __PT_GPRS + 28
SP_R8 = STACK_FRAME_OVERHEAD + __PT_GPRS + 32
SP_R9 = STACK_FRAME_OVERHEAD + __PT_GPRS + 36
SP_R10 = STACK_FRAME_OVERHEAD + __PT_GPRS + 40
SP_R11 = STACK_FRAME_OVERHEAD + __PT_GPRS + 44
SP_R12 = STACK_FRAME_OVERHEAD + __PT_GPRS + 48
SP_R13 = STACK_FRAME_OVERHEAD + __PT_GPRS + 52
SP_R14 = STACK_FRAME_OVERHEAD + __PT_GPRS + 56
SP_R15 = STACK_FRAME_OVERHEAD + __PT_GPRS + 60
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
_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)
STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
STACK_SIZE = 1 << STACK_SHIFT
#define BASED(name) name-system_call(%r13)
#ifdef CONFIG_TRACE_IRQFLAGS
.macro TRACE_IRQS_ON
basr %r2,%r0
l %r1,BASED(.Ltrace_irq_on_caller)
basr %r14,%r1
.endm
.macro TRACE_IRQS_OFF
basr %r2,%r0
l %r1,BASED(.Ltrace_irq_off_caller)
basr %r14,%r1
.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
l %r1,BASED(.Llockdep_sys_exit)
basr %r14,%r1
0:
.endm
#else
#define LOCKDEP_SYS_EXIT
#endif
/*
* 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 UPDATE_VTIME lc_from,lc_to,lc_sum
lm %r10,%r11,\lc_from
sl %r10,\lc_to
sl %r11,\lc_to+4
bc 3,BASED(0f)
sl %r10,BASED(.Lc_1)
0: al %r10,\lc_sum
al %r11,\lc_sum+4
bc 12,BASED(1f)
al %r10,BASED(.Lc_1)
1: stm %r10,%r11,\lc_sum
.endm
.macro SAVE_ALL_SVC psworg,savearea
stm %r12,%r15,\savearea
l %r13,__LC_SVC_NEW_PSW+4 # load &system_call to %r13
l %r15,__LC_KERNEL_STACK # problem state -> load ksp
s %r15,BASED(.Lc_spsize) # make room for registers & psw
.endm
.macro SAVE_ALL_BASE savearea
stm %r12,%r15,\savearea
l %r13,__LC_SVC_NEW_PSW+4 # load &system_call to %r13
.endm
.macro SAVE_ALL_PGM psworg,savearea
tm \psworg+1,0x01 # test problem state bit
#ifdef CONFIG_CHECK_STACK
bnz BASED(1f)
tml %r15,STACK_SIZE - CONFIG_STACK_GUARD
bnz BASED(2f)
la %r12,\psworg
b BASED(stack_overflow)
#else
bz BASED(2f)
#endif
1: l %r15,__LC_KERNEL_STACK # problem state -> load ksp
2: s %r15,BASED(.Lc_spsize) # make room for registers & psw
.endm
.macro SAVE_ALL_ASYNC psworg,savearea
stm %r12,%r15,\savearea
l %r13,__LC_SVC_NEW_PSW+4 # load &system_call to %r13
la %r12,\psworg
tm \psworg+1,0x01 # test problem state bit
bnz BASED(1f) # from user -> load async stack
clc \psworg+4(4),BASED(.Lcritical_end)
bhe BASED(0f)
clc \psworg+4(4),BASED(.Lcritical_start)
bl BASED(0f)
l %r14,BASED(.Lcleanup_critical)
basr %r14,%r14
tm 1(%r12),0x01 # retest problem state after cleanup
bnz BASED(1f)
0: l %r14,__LC_ASYNC_STACK # are we already on the async stack ?
slr %r14,%r15
sra %r14,STACK_SHIFT
#ifdef CONFIG_CHECK_STACK
bnz BASED(1f)
tml %r15,STACK_SIZE - CONFIG_STACK_GUARD
bnz BASED(2f)
b BASED(stack_overflow)
#else
bz BASED(2f)
#endif
1: l %r15,__LC_ASYNC_STACK
2: s %r15,BASED(.Lc_spsize) # make room for registers & psw
.endm
.macro CREATE_STACK_FRAME savearea
xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
st %r2,SP_ORIG_R2(%r15) # store original content of gpr 2
mvc SP_R12(16,%r15),\savearea # move %r12-%r15 to stack
stm %r0,%r11,SP_R0(%r15) # store gprs %r0-%r11 to kernel stack
.endm
.macro RESTORE_ALL psworg,sync
mvc \psworg(8),SP_PSW(%r15) # move user PSW to lowcore
.if !\sync
ni \psworg+1,0xfd # clear wait state bit
.endif
lm %r0,%r15,SP_R0(%r15) # load gprs 0-15 of user
stpt __LC_EXIT_TIMER
lpsw \psworg # back to caller
.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
*/
ENTRY(__switch_to)
basr %r1,0
0: l %r4,__THREAD_info(%r2) # get thread_info of prev
l %r5,__THREAD_info(%r3) # get thread_info of next
tm __TI_flags+3(%r4),_TIF_MCCK_PENDING # machine check pending?
bz 1f-0b(%r1)
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
1: stm %r6,%r15,__SF_GPRS(%r15) # store gprs of prev task
st %r15,__THREAD_ksp(%r2) # store kernel stack of prev
l %r15,__THREAD_ksp(%r3) # load kernel stack of next
lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4
lm %r6,%r15,__SF_GPRS(%r15) # load gprs of next task
st %r3,__LC_CURRENT # store task struct of next
mvc __LC_CURRENT_PID(4,%r0),__TASK_pid(%r3) # store pid of next
st %r5,__LC_THREAD_INFO # store thread info of next
ahi %r5,STACK_SIZE # end of kernel stack of next
st %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.
*/
ENTRY(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(8,%r15),__LC_SVC_OLD_PSW
mvc SP_ILC(4,%r15),__LC_SVC_ILC
l %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
sysc_do_svc:
xr %r7,%r7
icm %r7,3,SP_SVCNR(%r15) # load svc number and test for svc 0
bnz BASED(sysc_nr_ok) # svc number > 0
# svc 0: system call number in %r1
cl %r1,BASED(.Lnr_syscalls)
bnl BASED(sysc_nr_ok)
sth %r1,SP_SVCNR(%r15)
lr %r7,%r1 # copy svc number to %r7
sysc_nr_ok:
sll %r7,2 # svc number *4
l %r10,BASED(.Lsysc_table)
tm __TI_flags+2(%r12),_TIF_SYSCALL
mvc SP_ARGS(4,%r15),SP_R7(%r15)
l %r8,0(%r7,%r10) # get system call addr.
bnz BASED(sysc_tracesys)
basr %r14,%r8 # call sys_xxxx
st %r2,SP_R2(%r15) # store return value (change R2 on stack)
sysc_return:
LOCKDEP_SYS_EXIT
sysc_tif:
tm __TI_flags+3(%r12),_TIF_WORK_SVC
bnz BASED(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 ?
bno BASED(sysc_restore)
#
# One of the work bits is on. Find out which one.
#
sysc_work_tif:
tm __TI_flags+3(%r12),_TIF_MCCK_PENDING
bo BASED(sysc_mcck_pending)
tm __TI_flags+3(%r12),_TIF_NEED_RESCHED
bo BASED(sysc_reschedule)
tm __TI_flags+3(%r12),_TIF_SIGPENDING
bo BASED(sysc_sigpending)
tm __TI_flags+3(%r12),_TIF_NOTIFY_RESUME
bo BASED(sysc_notify_resume)
tm __TI_flags+3(%r12),_TIF_RESTART_SVC
bo BASED(sysc_restart)
tm __TI_flags+3(%r12),_TIF_PER_TRAP
bo BASED(sysc_singlestep)
b BASED(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 scheduler
#
# _TIF_MCCK_PENDING is set, call handler
#
sysc_mcck_pending:
l %r1,BASED(.Ls390_handle_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
la %r2,SP_PTREGS(%r15) # load pt_regs
l %r1,BASED(.Ldo_signal)
basr %r14,%r1 # call do_signal
tm __TI_flags+3(%r12),_TIF_RESTART_SVC
bo BASED(sysc_restart)
tm __TI_flags+3(%r12),_TIF_PER_TRAP
bo BASED(sysc_singlestep)
b BASED(sysc_return)
#
# _TIF_NOTIFY_RESUME is set, call do_notify_resume
#
sysc_notify_resume:
la %r2,SP_PTREGS(%r15) # load pt_regs
l %r1,BASED(.Ldo_notify_resume)
la %r14,BASED(sysc_return)
br %r1 # call do_notify_resume
#
# _TIF_RESTART_SVC is set, set up registers and restart svc
#
sysc_restart:
ni __TI_flags+3(%r12),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC
l %r7,SP_R2(%r15) # load new svc number
mvc SP_R2(4,%r15),SP_ORIG_R2(%r15) # restore first argument
lm %r2,%r6,SP_R2(%r15) # load svc arguments
sth %r7,SP_SVCNR(%r15)
b BASED(sysc_nr_ok) # restart svc
#
# _TIF_PER_TRAP is set, call do_per_trap
#
sysc_singlestep:
ni __TI_flags+3(%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
l %r1,BASED(.Lhandle_per) # load adr. of per handler
la %r14,BASED(sysc_return) # load adr. of system return
br %r1 # branch to do_per_trap
#
# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
# and after the system call
#
sysc_tracesys:
l %r1,BASED(.Ltrace_entry)
la %r2,SP_PTREGS(%r15) # load pt_regs
la %r3,0
xr %r0,%r0
icm %r0,3,SP_SVCNR(%r15)
st %r0,SP_R2(%r15)
basr %r14,%r1
cl %r2,BASED(.Lnr_syscalls)
bnl BASED(sysc_tracenogo)
lr %r7,%r2
sll %r7,2 # svc number *4
l %r8,0(%r7,%r10)
sysc_tracego:
lm %r3,%r6,SP_R3(%r15)
mvc SP_ARGS(4,%r15),SP_R7(%r15)
l %r2,SP_ORIG_R2(%r15)
basr %r14,%r8 # call sys_xxx
st %r2,SP_R2(%r15) # store return value
sysc_tracenogo:
tm __TI_flags+2(%r12),_TIF_SYSCALL
bz BASED(sysc_return)
l %r1,BASED(.Ltrace_exit)
la %r2,SP_PTREGS(%r15) # load pt_regs
la %r14,BASED(sysc_return)
br %r1
#
# a new process exits the kernel with ret_from_fork
#
ENTRY(ret_from_fork)
l %r13,__LC_SVC_NEW_PSW+4
l %r12,__LC_THREAD_INFO # load pointer to thread_info struct
tm SP_PSW+1(%r15),0x01 # forking a kernel thread ?
bo BASED(0f)
st %r15,SP_R15(%r15) # store stack pointer for new kthread
0: l %r1,BASED(.Lschedtail)
basr %r14,%r1
TRACE_IRQS_ON
stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
b BASED(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
s %r15,BASED(.Lc_spsize)
st %r14,__SF_BACKCHAIN(%r15)
la %r12,SP_PTREGS(%r15)
xc 0(__PT_SIZE,%r12),0(%r12)
l %r1,BASED(.Ldo_execve)
lr %r5,%r12
basr %r14,%r1
ltr %r2,%r2
be BASED(0f)
a %r15,BASED(.Lc_spsize)
lm %r12,%r15,48(%r15)
br %r14
# execve succeeded.
0: stnsm __SF_EMPTY(%r15),0xfc # disable interrupts
l %r15,__LC_KERNEL_STACK # load ksp
s %r15,BASED(.Lc_spsize) # make room for registers & psw
mvc SP_PTREGS(__PT_SIZE,%r15),0(%r12) # copy pt_regs
l %r12,__LC_THREAD_INFO
xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
l %r1,BASED(.Lexecve_tail)
basr %r14,%r1
b BASED(sysc_return)
/*
* Program check handler routine
*/
ENTRY(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
SAVE_ALL_BASE __LC_SAVE_AREA
tm __LC_PGM_INT_CODE+1,0x80 # check whether we got a per exception
bnz BASED(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(8,%r15),__LC_PGM_OLD_PSW
l %r12,__LC_THREAD_INFO # load pointer to thread_info struct
tm SP_PSW+1(%r15),0x01 # interrupting from user ?
bz BASED(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
pgm_no_vtime:
l %r3,__LC_PGM_ILC # load program interruption code
l %r4,__LC_TRANS_EXC_CODE
REENABLE_IRQS
la %r8,0x7f
nr %r8,%r3
sll %r8,2
l %r1,BASED(.Ljump_table)
l %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:
b BASED(sysc_return)
#
# handle per exception
#
pgm_per:
tm __LC_PGM_OLD_PSW,0x40 # test if per event recording is on
bnz BASED(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(8),__LC_SVC_NEW_PSW
be BASED(pgm_svcper)
# no interesting special case, ignore PER event
lm %r12,%r15,__LC_SAVE_AREA
lpsw 0x28
#
# 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(8,%r15),__LC_PGM_OLD_PSW
l %r12,__LC_THREAD_INFO # load pointer to thread_info struct
tm SP_PSW+1(%r15),0x01 # interrupting from user ?
bz BASED(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
pgm_no_vtime2:
l %r1,__TI_task(%r12)
tm SP_PSW+1(%r15),0x01 # kernel per event ?
bz BASED(kernel_per)
mvc __THREAD_per_cause(2,%r1),__LC_PER_CAUSE
mvc __THREAD_per_address(4,%r1),__LC_PER_ADDRESS
mvc __THREAD_per_paid(1,%r1),__LC_PER_PAID
oi __TI_flags+3(%r12),_TIF_PER_TRAP # set TIF_PER_TRAP
l %r3,__LC_PGM_ILC # load program interruption code
l %r4,__LC_TRANS_EXC_CODE
REENABLE_IRQS
la %r8,0x7f
nr %r8,%r3 # clear per-event-bit and ilc
be BASED(pgm_exit2) # only per or per+check ?
sll %r8,2
l %r1,BASED(.Ljump_table)
l %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:
b BASED(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(8,%r15),__LC_SVC_OLD_PSW
mvc SP_ILC(4,%r15),__LC_SVC_ILC
l %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
l %r8,__TI_task(%r12)
mvc __THREAD_per_cause(2,%r8),__LC_PER_CAUSE
mvc __THREAD_per_address(4,%r8),__LC_PER_ADDRESS
mvc __THREAD_per_paid(1,%r8),__LC_PER_PAID
oi __TI_flags+3(%r12),_TIF_PER_TRAP # set TIF_PER_TRAP
stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
lm %r2,%r6,SP_R2(%r15) # load svc arguments
b BASED(sysc_do_svc)
#
# per was called from kernel, must be kprobes
#
kernel_per:
REENABLE_IRQS
xc SP_SVCNR(2,%r15),SP_SVCNR(%r15)
la %r2,SP_PTREGS(%r15) # address of register-save area
l %r1,BASED(.Lhandle_per) # load adr. of per handler
basr %r14,%r1 # branch to do_single_step
b BASED(pgm_exit)
/*
* IO interrupt handler routine
*/
ENTRY(io_int_handler)
stck __LC_INT_CLOCK
stpt __LC_ASYNC_ENTER_TIMER
SAVE_ALL_ASYNC __LC_IO_OLD_PSW,__LC_SAVE_AREA+16
CREATE_STACK_FRAME __LC_SAVE_AREA+16
mvc SP_PSW(8,%r15),0(%r12) # move user PSW to stack
l %r12,__LC_THREAD_INFO # load pointer to thread_info struct
tm SP_PSW+1(%r15),0x01 # interrupting from user ?
bz BASED(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
io_no_vtime:
TRACE_IRQS_OFF
l %r1,BASED(.Ldo_IRQ) # load address of do_IRQ
la %r2,SP_PTREGS(%r15) # address of register-save area
basr %r14,%r1 # branch to standard irq handler
io_return:
LOCKDEP_SYS_EXIT
TRACE_IRQS_ON
io_tif:
tm __TI_flags+3(%r12),_TIF_WORK_INT
bnz BASED(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 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 ?
bo BASED(io_work_user) # yes -> do resched & signal
#ifdef CONFIG_PREEMPT
# check for preemptive scheduling
icm %r0,15,__TI_precount(%r12)
bnz BASED(io_restore) # preemption disabled
tm __TI_flags+3(%r12),_TIF_NEED_RESCHED
bno BASED(io_restore)
# switch to kernel stack
l %r1,SP_R15(%r15)
s %r1,BASED(.Lc_spsize)
mvc SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain
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_schedule_irq)
basr %r14,%r1 # call preempt_schedule_irq
b BASED(io_return)
#else
b BASED(io_restore)
#endif
#
# Need to do work before returning to userspace, switch to kernel stack
#
io_work_user:
l %r1,__LC_KERNEL_STACK
s %r1,BASED(.Lc_spsize)
mvc SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain
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
bo BASED(io_mcck_pending)
tm __TI_flags+3(%r12),_TIF_NEED_RESCHED
bo BASED(io_reschedule)
tm __TI_flags+3(%r12),_TIF_SIGPENDING
bo BASED(io_sigpending)
tm __TI_flags+3(%r12),_TIF_NOTIFY_RESUME
bo BASED(io_notify_resume)
b BASED(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(.Ls390_handle_mcck)
basr %r14,%r1 # TIF bit will be cleared by handler
TRACE_IRQS_OFF
b BASED(io_return)
#
# _TIF_NEED_RESCHED is set, call schedule
#
io_reschedule:
# TRACE_IRQS_ON already done at io_return
l %r1,BASED(.Lschedule)
stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
basr %r14,%r1 # call scheduler
stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts
TRACE_IRQS_OFF
b BASED(io_return)
#
# _TIF_SIGPENDING 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
l %r1,BASED(.Ldo_signal)
basr %r14,%r1 # call do_signal
stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts
TRACE_IRQS_OFF
b BASED(io_return)
#
# _TIF_SIGPENDING is set, call do_signal
#
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
l %r1,BASED(.Ldo_notify_resume)
basr %r14,%r1 # call do_signal
stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts
TRACE_IRQS_OFF
b BASED(io_return)
/*
* External interrupt handler routine
*/
ENTRY(ext_int_handler)
stck __LC_INT_CLOCK
stpt __LC_ASYNC_ENTER_TIMER
SAVE_ALL_ASYNC __LC_EXT_OLD_PSW,__LC_SAVE_AREA+16
CREATE_STACK_FRAME __LC_SAVE_AREA+16
mvc SP_PSW(8,%r15),0(%r12) # move user PSW to stack
l %r12,__LC_THREAD_INFO # load pointer to thread_info struct
tm SP_PSW+1(%r15),0x01 # interrupting from user ?
bz BASED(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
ext_no_vtime:
TRACE_IRQS_OFF
la %r2,SP_PTREGS(%r15) # address of register-save area
l %r3,__LC_CPU_ADDRESS # get cpu address + interruption code
l %r4,__LC_EXT_PARAMS # get external parameters
l %r1,BASED(.Ldo_extint)
basr %r14,%r1
b BASED(io_return)
__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
SAVE_ALL_BASE __LC_SAVE_AREA+32
la %r12,__LC_MCK_OLD_PSW
tm __LC_MCCK_CODE,0x80 # system damage?
bo BASED(mcck_int_main) # yes -> rest of mcck code invalid
mvc __LC_MCCK_ENTER_TIMER(8),__LC_CPU_TIMER_SAVE_AREA
tm __LC_MCCK_CODE+5,0x02 # stored cpu timer value valid?
bo BASED(1f)
la %r14,__LC_SYNC_ENTER_TIMER
clc 0(8,%r14),__LC_ASYNC_ENTER_TIMER
bl BASED(0f)
la %r14,__LC_ASYNC_ENTER_TIMER
0: clc 0(8,%r14),__LC_EXIT_TIMER
bl BASED(0f)
la %r14,__LC_EXIT_TIMER
0: clc 0(8,%r14),__LC_LAST_UPDATE_TIMER
bl BASED(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?
bno BASED(mcck_int_main) # no -> skip cleanup critical
tm __LC_MCK_OLD_PSW+1,0x01 # test problem state bit
bnz BASED(mcck_int_main) # from user -> load async stack
clc __LC_MCK_OLD_PSW+4(4),BASED(.Lcritical_end)
bhe BASED(mcck_int_main)
clc __LC_MCK_OLD_PSW+4(4),BASED(.Lcritical_start)
bl BASED(mcck_int_main)
l %r14,BASED(.Lcleanup_critical)
basr %r14,%r14
mcck_int_main:
l %r14,__LC_PANIC_STACK # are we already on the panic stack?
slr %r14,%r15
sra %r14,PAGE_SHIFT
be BASED(0f)
l %r15,__LC_PANIC_STACK # load panic stack
0: s %r15,BASED(.Lc_spsize) # make room for registers & psw
CREATE_STACK_FRAME __LC_SAVE_AREA+32
mvc SP_PSW(8,%r15),0(%r12)
l %r12,__LC_THREAD_INFO # load pointer to thread_info struct
tm __LC_MCCK_CODE+2,0x08 # mwp of old psw valid?
bno BASED(mcck_no_vtime) # no -> skip cleanup critical
tm SP_PSW+1(%r15),0x01 # interrupting from user ?
bz BASED(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
mcck_no_vtime:
la %r2,SP_PTREGS(%r15) # load pt_regs
l %r1,BASED(.Ls390_mcck)
basr %r14,%r1 # call machine check handler
tm SP_PSW+1(%r15),0x01 # returning to user ?
bno BASED(mcck_return)
l %r1,__LC_KERNEL_STACK # switch to kernel stack
s %r1,BASED(.Lc_spsize)
mvc SP_PTREGS(__PT_SIZE,%r1),SP_PTREGS(%r15)
xc __SF_BACKCHAIN(4,%r1),__SF_BACKCHAIN(%r1) # clear back chain
lr %r15,%r1
stosm __SF_EMPTY(%r15),0x04 # turn dat on
tm __TI_flags+3(%r12),_TIF_MCCK_PENDING
bno BASED(mcck_return)
TRACE_IRQS_OFF
l %r1,BASED(.Ls390_handle_mcck)
basr %r14,%r1 # call machine check handler
TRACE_IRQS_ON
mcck_return:
mvc __LC_RETURN_MCCK_PSW(8),SP_PSW(%r15) # move return PSW
ni __LC_RETURN_MCCK_PSW+1,0xfd # clear wait state bit
tm __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
bno BASED(0f)
lm %r0,%r15,SP_R0(%r15) # load gprs 0-15
stpt __LC_EXIT_TIMER
lpsw __LC_RETURN_MCCK_PSW # back to caller
0: lm %r0,%r15,SP_R0(%r15) # load gprs 0-15
lpsw __LC_RETURN_MCCK_PSW # back to caller
RESTORE_ALL __LC_RETURN_MCCK_PSW,0
/*
* Restart interruption handler, kick starter for additional CPUs
*/
#ifdef CONFIG_SMP
__CPUINIT
ENTRY(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)
l %r15,__LC_SAVE_AREA+60 # load ksp
lctl %c0,%c15,__LC_CREGS_SAVE_AREA # get new ctl regs
lam %a0,%a15,__LC_AREGS_SAVE_AREA
lm %r6,%r15,__SF_GPRS(%r15) # load registers from clone
l %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
basr %r14,0
l %r14,restart_addr-.(%r14)
basr %r14,%r14 # branch to start_secondary
restart_addr:
.long start_secondary
.align 8
restart_vtime:
.long 0x7fffffff,0xffffffff
.previous
#else
/*
* If we do not run with SMP enabled, let the new CPU crash ...
*/
ENTRY(restart_int_handler)
basr %r1,0
restart_base:
lpsw restart_crash-restart_base(%r1)
.align 8
restart_crash:
.long 0x000a0000,0x00000000
restart_go:
#endif
#
# PSW restart interrupt handler
#
ENTRY(psw_restart_int_handler)
st %r15,__LC_SAVE_AREA_64(%r0) # save r15
basr %r15,0
0: l %r15,.Lrestart_stack-0b(%r15) # load restart stack
l %r15,0(%r15)
ahi %r15,-SP_SIZE # make room for pt_regs
stm %r0,%r14,SP_R0(%r15) # store gprs %r0-%r14 to stack
mvc SP_R15(4,%r15),__LC_SAVE_AREA_64(%r0)# store saved %r15 to stack
mvc SP_PSW(8,%r15),__LC_RST_OLD_PSW(%r0) # store restart old psw
xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # set backchain to 0
basr %r14,0
1: l %r14,.Ldo_restart-1b(%r14)
basr %r14,%r14
basr %r14,0 # load disabled wait PSW if
2: lpsw restart_psw_crash-2b(%r14) # do_restart returns
.align 4
.Ldo_restart:
.long do_restart
.Lrestart_stack:
.long restart_stack
.align 8
restart_psw_crash:
.long 0x000a0000,0x00000000 + restart_psw_crash
.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
sl %r15,BASED(.Lc_spsize)
mvc SP_PSW(8,%r15),0(%r12) # move user PSW to stack
stm %r0,%r11,SP_R0(%r15) # store gprs %r0-%r11 to kernel stack
la %r1,__LC_SAVE_AREA
ch %r12,BASED(.L0x020) # old psw addr == __LC_SVC_OLD_PSW ?
be BASED(0f)
ch %r12,BASED(.L0x028) # old psw addr == __LC_PGM_OLD_PSW ?
be BASED(0f)
la %r1,__LC_SAVE_AREA+16
0: mvc SP_R12(16,%r15),0(%r1) # move %r12-%r15 to stack
xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear back chain
l %r1,BASED(1f) # branch to kernel_stack_overflow
la %r2,SP_PTREGS(%r15) # load pt_regs
br %r1
1: .long kernel_stack_overflow
#endif
cleanup_table_system_call:
.long system_call + 0x80000000, sysc_do_svc + 0x80000000
cleanup_table_sysc_tif:
.long sysc_tif + 0x80000000, sysc_restore + 0x80000000
cleanup_table_sysc_restore:
.long sysc_restore + 0x80000000, sysc_done + 0x80000000
cleanup_table_io_tif:
.long io_tif + 0x80000000, io_restore + 0x80000000
cleanup_table_io_restore:
.long io_restore + 0x80000000, io_done + 0x80000000
cleanup_critical:
clc 4(4,%r12),BASED(cleanup_table_system_call)
bl BASED(0f)
clc 4(4,%r12),BASED(cleanup_table_system_call+4)
bl BASED(cleanup_system_call)
0:
clc 4(4,%r12),BASED(cleanup_table_sysc_tif)
bl BASED(0f)
clc 4(4,%r12),BASED(cleanup_table_sysc_tif+4)
bl BASED(cleanup_sysc_tif)
0:
clc 4(4,%r12),BASED(cleanup_table_sysc_restore)
bl BASED(0f)
clc 4(4,%r12),BASED(cleanup_table_sysc_restore+4)
bl BASED(cleanup_sysc_restore)
0:
clc 4(4,%r12),BASED(cleanup_table_io_tif)
bl BASED(0f)
clc 4(4,%r12),BASED(cleanup_table_io_tif+4)
bl BASED(cleanup_io_tif)
0:
clc 4(4,%r12),BASED(cleanup_table_io_restore)
bl BASED(0f)
clc 4(4,%r12),BASED(cleanup_table_io_restore+4)
bl BASED(cleanup_io_restore)
0:
br %r14
cleanup_system_call:
mvc __LC_RETURN_PSW(8),0(%r12)
clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+4)
bh BASED(0f)
mvc __LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER
c %r12,BASED(.Lmck_old_psw)
be BASED(0f)
mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
0: c %r12,BASED(.Lmck_old_psw)
la %r12,__LC_SAVE_AREA+32
be BASED(0f)
la %r12,__LC_SAVE_AREA+16
0: clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+8)
bhe BASED(cleanup_vtime)
clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn)
bh BASED(0f)
mvc __LC_SAVE_AREA(16),0(%r12)
0: st %r13,4(%r12)
l %r15,__LC_KERNEL_STACK # problem state -> load ksp
s %r15,BASED(.Lc_spsize) # make room for registers & psw
st %r15,12(%r12)
CREATE_STACK_FRAME __LC_SAVE_AREA
mvc SP_PSW(8,%r15),__LC_SVC_OLD_PSW
mvc SP_ILC(4,%r15),__LC_SVC_ILC
mvc 0(4,%r12),__LC_THREAD_INFO
cleanup_vtime:
clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+12)
bhe BASED(cleanup_stime)
UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
cleanup_stime:
clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+16)
bh BASED(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
mvc __LC_RETURN_PSW+4(4),BASED(cleanup_table_system_call+4)
la %r12,__LC_RETURN_PSW
br %r14
cleanup_system_call_insn:
.long sysc_saveall + 0x80000000
.long system_call + 0x80000000
.long sysc_vtime + 0x80000000
.long sysc_stime + 0x80000000
.long sysc_update + 0x80000000
cleanup_sysc_tif:
mvc __LC_RETURN_PSW(4),0(%r12)
mvc __LC_RETURN_PSW+4(4),BASED(cleanup_table_sysc_tif)
la %r12,__LC_RETURN_PSW
br %r14
cleanup_sysc_restore:
clc 4(4,%r12),BASED(cleanup_sysc_restore_insn)
be BASED(2f)
mvc __LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER
c %r12,BASED(.Lmck_old_psw)
be BASED(0f)
mvc __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER
0: clc 4(4,%r12),BASED(cleanup_sysc_restore_insn+4)
be BASED(2f)
mvc __LC_RETURN_PSW(8),SP_PSW(%r15)
c %r12,BASED(.Lmck_old_psw)
la %r12,__LC_SAVE_AREA+32
be BASED(1f)
la %r12,__LC_SAVE_AREA+16
1: mvc 0(16,%r12),SP_R12(%r15)
lm %r0,%r11,SP_R0(%r15)
l %r15,SP_R15(%r15)
2: la %r12,__LC_RETURN_PSW
br %r14
cleanup_sysc_restore_insn:
.long sysc_done - 4 + 0x80000000
.long sysc_done - 8 + 0x80000000
cleanup_io_tif:
mvc __LC_RETURN_PSW(4),0(%r12)
mvc __LC_RETURN_PSW+4(4),BASED(cleanup_table_io_tif)
la %r12,__LC_RETURN_PSW
br %r14
cleanup_io_restore:
clc 4(4,%r12),BASED(cleanup_io_restore_insn)
be BASED(1f)
mvc __LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER
clc 4(4,%r12),BASED(cleanup_io_restore_insn+4)
be BASED(1f)
mvc __LC_RETURN_PSW(8),SP_PSW(%r15)
mvc __LC_SAVE_AREA+32(16),SP_R12(%r15)
lm %r0,%r11,SP_R0(%r15)
l %r15,SP_R15(%r15)
1: la %r12,__LC_RETURN_PSW
br %r14
cleanup_io_restore_insn:
.long io_done - 4 + 0x80000000
.long io_done - 8 + 0x80000000
/*
* Integer constants
*/
.align 4
.Lc_spsize: .long SP_SIZE
.Lc_overhead: .long STACK_FRAME_OVERHEAD
.Lnr_syscalls: .long NR_syscalls
.L0x018: .short 0x018
.L0x020: .short 0x020
.L0x028: .short 0x028
.L0x030: .short 0x030
.L0x038: .short 0x038
.Lc_1: .long 1
/*
* Symbol constants
*/
.Ls390_mcck: .long s390_do_machine_check
.Ls390_handle_mcck:
.long s390_handle_mcck
.Lmck_old_psw: .long __LC_MCK_OLD_PSW
.Ldo_IRQ: .long do_IRQ
.Ldo_extint: .long do_extint
.Ldo_signal: .long do_signal
.Ldo_notify_resume:
.long do_notify_resume
.Lhandle_per: .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_schedule_irq:
.long preempt_schedule_irq
#endif
.Ltrace_entry: .long do_syscall_trace_enter
.Ltrace_exit: .long do_syscall_trace_exit
.Lschedtail: .long schedule_tail
.Lsysc_table: .long sys_call_table
#ifdef CONFIG_TRACE_IRQFLAGS
.Ltrace_irq_on_caller:
.long trace_hardirqs_on_caller
.Ltrace_irq_off_caller:
.long trace_hardirqs_off_caller
#endif
#ifdef CONFIG_LOCKDEP
.Llockdep_sys_exit:
.long lockdep_sys_exit
#endif
.Lcritical_start:
.long __critical_start + 0x80000000
.Lcritical_end:
.long __critical_end + 0x80000000
.Lcleanup_critical:
.long cleanup_critical
.section .rodata, "a"
#define SYSCALL(esa,esame,emu) .long esa
.globl sys_call_table
sys_call_table:
#include "syscalls.S"
#undef SYSCALL
