diff options
Diffstat (limited to 'arch/s390/kernel/entry.S')
| -rw-r--r-- | arch/s390/kernel/entry.S | 868 |
1 files changed, 868 insertions, 0 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S new file mode 100644 index 00000000000..c0e09b33feb --- /dev/null +++ b/arch/s390/kernel/entry.S @@ -0,0 +1,868 @@ +/* + * arch/s390/kernel/entry.S + * S390 low-level entry points. + * + * S390 version + * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation + * 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), + */ + +#include <linux/sys.h> +#include <linux/linkage.h> +#include <linux/config.h> +#include <asm/cache.h> +#include <asm/lowcore.h> +#include <asm/errno.h> +#include <asm/ptrace.h> +#include <asm/thread_info.h> +#include <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_TRAP = STACK_FRAME_OVERHEAD + __PT_TRAP +SP_SIZE = STACK_FRAME_OVERHEAD + __PT_SIZE + +_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \ + _TIF_RESTART_SVC | _TIF_SINGLE_STEP ) +_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED) + +STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER +STACK_SIZE = 1 << STACK_SHIFT + +#define BASED(name) name-system_call(%r13) + +/* + * 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 STORE_TIMER lc_offset +#ifdef CONFIG_VIRT_CPU_ACCOUNTING + stpt \lc_offset +#endif + .endm + +#ifdef CONFIG_VIRT_CPU_ACCOUNTING + .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 +#endif + + .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 psworg,savearea,sync + la %r12,\psworg + .if \sync + tm \psworg+1,0x01 # test problem state bit + bz BASED(2f) # skip stack setup save + l %r15,__LC_KERNEL_STACK # problem state -> load ksp + .else + 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 0(%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 + be BASED(2f) +1: l %r15,__LC_ASYNC_STACK + .endif +#ifdef CONFIG_CHECK_STACK + b BASED(3f) +2: tml %r15,STACK_SIZE - CONFIG_STACK_GUARD + bz BASED(stack_overflow) +3: +#endif +2: s %r15,BASED(.Lc_spsize) # make room for registers & psw + mvc SP_PSW(8,%r15),0(%r12) # move user PSW to stack + la %r12,\psworg + st %r2,SP_ORIG_R2(%r15) # store original content of gpr 2 + icm %r12,12,__LC_SVC_ILC + stm %r0,%r11,SP_R0(%r15) # store gprs %r0-%r11 to kernel stack + st %r12,SP_ILC(%r15) + mvc SP_R12(16,%r15),\savearea # move %r12-%r15 to stack + la %r12,0 + st %r12,__SF_BACKCHAIN(%r15) # clear back chain + .endm + + .macro RESTORE_ALL sync + mvc __LC_RETURN_PSW(8),SP_PSW(%r15) # move user PSW to lowcore + .if !\sync + ni __LC_RETURN_PSW+1,0xfd # clear wait state bit + .endif + lm %r0,%r15,SP_R0(%r15) # load gprs 0-15 of user + STORE_TIMER __LC_EXIT_TIMER + lpsw __LC_RETURN_PSW # back to caller + .endm + +/* + * Scheduler resume function, called by switch_to + * gpr2 = (task_struct *) prev + * gpr3 = (task_struct *) next + * Returns: + * gpr2 = prev + */ + .globl __switch_to +__switch_to: + basr %r1,0 +__switch_to_base: + tm __THREAD_per(%r3),0xe8 # new process is using per ? + bz __switch_to_noper-__switch_to_base(%r1) # if not we're fine + stctl %c9,%c11,__SF_EMPTY(%r15) # We are using per stuff + clc __THREAD_per(12,%r3),__SF_EMPTY(%r15) + be __switch_to_noper-__switch_to_base(%r1) # we got away w/o bashing TLB's + lctl %c9,%c11,__THREAD_per(%r3) # Nope we didn't +__switch_to_noper: + stm %r6,%r15,__SF_GPRS(%r15)# store __switch_to registers of prev task + st %r15,__THREAD_ksp(%r2) # store kernel stack to prev->tss.ksp + l %r15,__THREAD_ksp(%r3) # load kernel stack from next->tss.ksp + lm %r6,%r15,__SF_GPRS(%r15)# load __switch_to registers of next task + st %r3,__LC_CURRENT # __LC_CURRENT = current task struct + lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4 + l %r3,__THREAD_info(%r3) # load thread_info from task struct + st %r3,__LC_THREAD_INFO + ahi %r3,STACK_SIZE + st %r3,__LC_KERNEL_STACK # __LC_KERNEL_STACK = new 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: + STORE_TIMER __LC_SYNC_ENTER_TIMER +sysc_saveall: + SAVE_ALL_BASE __LC_SAVE_AREA + SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1 + lh %r7,0x8a # get svc number from lowcore +#ifdef CONFIG_VIRT_CPU_ACCOUNTING +sysc_vtime: + tm SP_PSW+1(%r15),0x01 # interrupting from user ? + bz BASED(sysc_do_svc) + 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 +#endif +sysc_do_svc: + l %r9,__LC_THREAD_INFO # load pointer to thread_info struct + sla %r7,2 # *4 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) + lr %r7,%r1 # copy svc number to %r7 + sla %r7,2 # *4 +sysc_nr_ok: + mvc SP_ARGS(4,%r15),SP_R7(%r15) +sysc_do_restart: + tm __TI_flags+3(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT) + l %r8,sys_call_table-system_call(%r7,%r13) # 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) + # ATTENTION: check sys_execve_glue before + # changing anything here !! + +sysc_return: + tm SP_PSW+1(%r15),0x01 # returning to user ? + bno BASED(sysc_leave) + tm __TI_flags+3(%r9),_TIF_WORK_SVC + bnz BASED(sysc_work) # there is work to do (signals etc.) +sysc_leave: + RESTORE_ALL 1 + +# +# recheck if there is more work to do +# +sysc_work_loop: + tm __TI_flags+3(%r9),_TIF_WORK_SVC + bz BASED(sysc_leave) # there is no work to do +# +# One of the work bits is on. Find out which one. +# +sysc_work: + tm __TI_flags+3(%r9),_TIF_NEED_RESCHED + bo BASED(sysc_reschedule) + tm __TI_flags+3(%r9),_TIF_SIGPENDING + bo BASED(sysc_sigpending) + tm __TI_flags+3(%r9),_TIF_RESTART_SVC + bo BASED(sysc_restart) + tm __TI_flags+3(%r9),_TIF_SINGLE_STEP + bo BASED(sysc_singlestep) + b BASED(sysc_leave) + +# +# _TIF_NEED_RESCHED is set, call schedule +# +sysc_reschedule: + l %r1,BASED(.Lschedule) + la %r14,BASED(sysc_work_loop) + br %r1 # call scheduler + +# +# _TIF_SIGPENDING is set, call do_signal +# +sysc_sigpending: + ni __TI_flags+3(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP + la %r2,SP_PTREGS(%r15) # load pt_regs + sr %r3,%r3 # clear *oldset + l %r1,BASED(.Ldo_signal) + basr %r14,%r1 # call do_signal + tm __TI_flags+3(%r9),_TIF_RESTART_SVC + bo BASED(sysc_restart) + tm __TI_flags+3(%r9),_TIF_SINGLE_STEP + bo BASED(sysc_singlestep) + b BASED(sysc_leave) # out of here, do NOT recheck + +# +# _TIF_RESTART_SVC is set, set up registers and restart svc +# +sysc_restart: + ni __TI_flags+3(%r9),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC + l %r7,SP_R2(%r15) # load new svc number + sla %r7,2 + mvc SP_R2(4,%r15),SP_ORIG_R2(%r15) # restore first argument + lm %r2,%r6,SP_R2(%r15) # load svc arguments + b BASED(sysc_do_restart) # restart svc + +# +# _TIF_SINGLE_STEP is set, call do_single_step +# +sysc_singlestep: + ni __TI_flags+3(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP + mvi SP_TRAP+1(%r15),0x28 # set trap indication to pgm check + 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_single_step + +__critical_end: + +# +# call trace before and after sys_call +# +sysc_tracesys: + l %r1,BASED(.Ltrace) + la %r2,SP_PTREGS(%r15) # load pt_regs + la %r3,0 + srl %r7,2 + st %r7,SP_R2(%r15) + basr %r14,%r1 + clc SP_R2(4,%r15),BASED(.Lnr_syscalls) + bnl BASED(sysc_tracenogo) + l %r7,SP_R2(%r15) # strace might have changed the + sll %r7,2 # system call + l %r8,sys_call_table-system_call(%r7,%r13) +sysc_tracego: + lm %r3,%r6,SP_R3(%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+3(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT) + bz BASED(sysc_return) + l %r1,BASED(.Ltrace) + la %r2,SP_PTREGS(%r15) # load pt_regs + la %r3,1 + la %r14,BASED(sysc_return) + br %r1 + +# +# a new process exits the kernel with ret_from_fork +# + .globl ret_from_fork +ret_from_fork: + l %r13,__LC_SVC_NEW_PSW+4 + l %r9,__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 + stosm __SF_EMPTY(%r15),0x03 # reenable interrupts + b BASED(sysc_return) + +# +# clone, fork, vfork, exec and sigreturn need glue, +# because they all expect pt_regs as parameter, +# but are called with different parameter. +# return-address is set up above +# +sys_clone_glue: + la %r2,SP_PTREGS(%r15) # load pt_regs + l %r1,BASED(.Lclone) + br %r1 # branch to sys_clone + +sys_fork_glue: + la %r2,SP_PTREGS(%r15) # load pt_regs + l %r1,BASED(.Lfork) + br %r1 # branch to sys_fork + +sys_vfork_glue: + la %r2,SP_PTREGS(%r15) # load pt_regs + l %r1,BASED(.Lvfork) + br %r1 # branch to sys_vfork + +sys_execve_glue: + la %r2,SP_PTREGS(%r15) # load pt_regs + l %r1,BASED(.Lexecve) + lr %r12,%r14 # save return address + basr %r14,%r1 # call sys_execve + ltr %r2,%r2 # check if execve failed + bnz 0(%r12) # it did fail -> store result in gpr2 + b 4(%r12) # SKIP ST 2,SP_R2(15) after BASR 14,8 + # in system_call/sysc_tracesys + +sys_sigreturn_glue: + la %r2,SP_PTREGS(%r15) # load pt_regs as parameter + l %r1,BASED(.Lsigreturn) + br %r1 # branch to sys_sigreturn + +sys_rt_sigreturn_glue: + la %r2,SP_PTREGS(%r15) # load pt_regs as parameter + l %r1,BASED(.Lrt_sigreturn) + br %r1 # branch to sys_sigreturn + +# +# sigsuspend and rt_sigsuspend need pt_regs as an additional +# parameter and they have to skip the store of %r2 into the +# user register %r2 because the return value was set in +# sigsuspend and rt_sigsuspend already and must not be overwritten! +# + +sys_sigsuspend_glue: + lr %r5,%r4 # move mask back + lr %r4,%r3 # move history1 parameter + lr %r3,%r2 # move history0 parameter + la %r2,SP_PTREGS(%r15) # load pt_regs as first parameter + l %r1,BASED(.Lsigsuspend) + la %r14,4(%r14) # skip store of return value + br %r1 # branch to sys_sigsuspend + +sys_rt_sigsuspend_glue: + lr %r4,%r3 # move sigsetsize parameter + lr %r3,%r2 # move unewset parameter + la %r2,SP_PTREGS(%r15) # load pt_regs as first parameter + l %r1,BASED(.Lrt_sigsuspend) + la %r14,4(%r14) # skip store of return value + br %r1 # branch to sys_rt_sigsuspend + +sys_sigaltstack_glue: + la %r4,SP_PTREGS(%r15) # load pt_regs as parameter + l %r1,BASED(.Lsigaltstack) + br %r1 # branch to sys_sigreturn + + +/* + * 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?). + */ + STORE_TIMER __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 __LC_PGM_OLD_PSW,__LC_SAVE_AREA,1 +#ifdef CONFIG_VIRT_CPU_ACCOUNTING + 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: +#endif + l %r9,__LC_THREAD_INFO # load pointer to thread_info struct + l %r3,__LC_PGM_ILC # load program interruption code + la %r8,0x7f + nr %r8,%r3 +pgm_do_call: + l %r7,BASED(.Ljump_table) + sll %r8,2 + l %r7,0(%r8,%r7) # load address of handler routine + la %r2,SP_PTREGS(%r15) # address of register-save area + la %r14,BASED(sysc_return) + br %r7 # branch to interrupt-handler + +# +# 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 __LC_PGM_OLD_PSW,__LC_SAVE_AREA,1 +#ifdef CONFIG_VIRT_CPU_ACCOUNTING + 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: +#endif + l %r9,__LC_THREAD_INFO # load pointer to thread_info struct + l %r1,__TI_task(%r9) + mvc __THREAD_per+__PER_atmid(2,%r1),__LC_PER_ATMID + mvc __THREAD_per+__PER_address(4,%r1),__LC_PER_ADDRESS + mvc __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID + oi __TI_flags+3(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP + l %r3,__LC_PGM_ILC # load program interruption code + la %r8,0x7f + nr %r8,%r3 # clear per-event-bit and ilc + be BASED(sysc_return) # only per or per+check ? + b BASED(pgm_do_call) + +# +# it was a single stepped SVC that is causing all the trouble +# +pgm_svcper: + SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1 +#ifdef CONFIG_VIRT_CPU_ACCOUNTING + tm SP_PSW+1(%r15),0x01 # interrupting from user ? + bz BASED(pgm_no_vtime3) + 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_vtime3: +#endif + lh %r7,0x8a # get svc number from lowcore + l %r9,__LC_THREAD_INFO # load pointer to thread_info struct + l %r1,__TI_task(%r9) + mvc __THREAD_per+__PER_atmid(2,%r1),__LC_PER_ATMID + mvc __THREAD_per+__PER_address(4,%r1),__LC_PER_ADDRESS + mvc __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID + oi __TI_flags+3(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP + stosm __SF_EMPTY(%r15),0x03 # reenable interrupts + b BASED(sysc_do_svc) + +/* + * IO interrupt handler routine + */ + + .globl io_int_handler +io_int_handler: + STORE_TIMER __LC_ASYNC_ENTER_TIMER + stck __LC_INT_CLOCK + SAVE_ALL_BASE __LC_SAVE_AREA+16 + SAVE_ALL __LC_IO_OLD_PSW,__LC_SAVE_AREA+16,0 +#ifdef CONFIG_VIRT_CPU_ACCOUNTING + 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: +#endif + l %r9,__LC_THREAD_INFO # load pointer to thread_info struct + 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: + tm SP_PSW+1(%r15),0x01 # returning to user ? +#ifdef CONFIG_PREEMPT + bno BASED(io_preempt) # no -> check for preemptive scheduling +#else + bno BASED(io_leave) # no-> skip resched & signal +#endif + tm __TI_flags+3(%r9),_TIF_WORK_INT + bnz BASED(io_work) # there is work to do (signals etc.) +io_leave: + RESTORE_ALL 0 + +#ifdef CONFIG_PREEMPT +io_preempt: + icm %r0,15,__TI_precount(%r9) + bnz BASED(io_leave) + 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 +io_resume_loop: + tm __TI_flags+3(%r9),_TIF_NEED_RESCHED + bno BASED(io_leave) + mvc __TI_precount(4,%r9),BASED(.Lc_pactive) + stosm __SF_EMPTY(%r15),0x03 # reenable interrupts + l %r1,BASED(.Lschedule) + basr %r14,%r1 # call schedule + stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts + xc __TI_precount(4,%r9),__TI_precount(%r9) + b BASED(io_resume_loop) +#endif + +# +# switch to kernel stack, then check the TIF bits +# +io_work: + 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 and _TIF_NEED_RESCHED +# +io_work_loop: + tm __TI_flags+3(%r9),_TIF_NEED_RESCHED + bo BASED(io_reschedule) + tm __TI_flags+3(%r9),_TIF_SIGPENDING + bo BASED(io_sigpending) + b BASED(io_leave) + +# +# _TIF_NEED_RESCHED is set, call schedule +# +io_reschedule: + 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 + tm __TI_flags+3(%r9),_TIF_WORK_INT + bz BASED(io_leave) # there is no work to do + b BASED(io_work_loop) + +# +# _TIF_SIGPENDING is set, call do_signal +# +io_sigpending: + stosm __SF_EMPTY(%r15),0x03 # reenable interrupts + la %r2,SP_PTREGS(%r15) # load pt_regs + sr %r3,%r3 # clear *oldset + l %r1,BASED(.Ldo_signal) + basr %r14,%r1 # call do_signal + stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts + b BASED(io_leave) # out of here, do NOT recheck + +/* + * External interrupt handler routine + */ + + .globl ext_int_handler +ext_int_handler: + STORE_TIMER __LC_ASYNC_ENTER_TIMER + stck __LC_INT_CLOCK + SAVE_ALL_BASE __LC_SAVE_AREA+16 + SAVE_ALL __LC_EXT_OLD_PSW,__LC_SAVE_AREA+16,0 +#ifdef CONFIG_VIRT_CPU_ACCOUNTING + 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: +#endif + l %r9,__LC_THREAD_INFO # load pointer to thread_info struct + la %r2,SP_PTREGS(%r15) # address of register-save area + lh %r3,__LC_EXT_INT_CODE # get interruption code + l %r1,BASED(.Ldo_extint) + basr %r14,%r1 + b BASED(io_return) + +/* + * Machine check handler routines + */ + + .globl mcck_int_handler +mcck_int_handler: + STORE_TIMER __LC_ASYNC_ENTER_TIMER + SAVE_ALL_BASE __LC_SAVE_AREA+32 + SAVE_ALL __LC_MCK_OLD_PSW,__LC_SAVE_AREA+32,0 +#ifdef CONFIG_VIRT_CPU_ACCOUNTING + tm SP_PSW+1(%r15),0x01 # interrupting from user ? + bz BASED(mcck_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 +mcck_no_vtime: +#endif + l %r1,BASED(.Ls390_mcck) + basr %r14,%r1 # call machine check handler +mcck_return: + RESTORE_ALL 0 + +#ifdef CONFIG_SMP +/* + * Restart interruption handler, kick starter for additional CPUs + */ + .globl restart_int_handler +restart_int_handler: + 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 + stosm __SF_EMPTY(%r15),0x04 # now we can turn dat on + basr %r14,0 + l %r14,restart_addr-.(%r14) + br %r14 # branch to start_secondary +restart_addr: + .long start_secondary +#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: + lpsw restart_crash-restart_base(%r1) + .align 8 +restart_crash: + .long 0x000a0000,0x00000000 +restart_go: +#endif + +#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_return: + .long sysc_return + 0x80000000, sysc_leave + 0x80000000 +cleanup_table_sysc_leave: + .long sysc_leave + 0x80000000, sysc_work_loop + 0x80000000 +cleanup_table_sysc_work_loop: + .long sysc_work_loop + 0x80000000, sysc_reschedule + 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_return) + bl BASED(0f) + clc 4(4,%r12),BASED(cleanup_table_sysc_return+4) + bl BASED(cleanup_sysc_return) +0: + clc 4(4,%r12),BASED(cleanup_table_sysc_leave) + bl BASED(0f) + clc 4(4,%r12),BASED(cleanup_table_sysc_leave+4) + bl BASED(cleanup_sysc_leave) +0: + clc 4(4,%r12),BASED(cleanup_table_sysc_work_loop) + bl BASED(0f) + clc 4(4,%r12),BASED(cleanup_table_sysc_work_loop+4) + bl BASED(cleanup_sysc_leave) +0: + br %r14 + +cleanup_system_call: + mvc __LC_RETURN_PSW(8),0(%r12) +#ifdef CONFIG_VIRT_CPU_ACCOUNTING + clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+4) + bh BASED(0f) + mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER +0: clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+8) + bhe BASED(cleanup_vtime) +#endif + clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn) + bh BASED(0f) + mvc __LC_SAVE_AREA(16),__LC_SAVE_AREA+16 +0: st %r13,__LC_SAVE_AREA+20 + SAVE_ALL __LC_SVC_OLD_PSW,__LC_SAVE_AREA,1 + st %r15,__LC_SAVE_AREA+28 + lh %r7,0x8a +#ifdef CONFIG_VIRT_CPU_ACCOUNTING +cleanup_vtime: + clc __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+12) + bhe BASED(cleanup_stime) + tm SP_PSW+1(%r15),0x01 # interrupting from user ? + bz BASED(cleanup_novtime) + 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 +cleanup_novtime: +#endif + 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 +#ifdef CONFIG_VIRT_CPU_ACCOUNTING + .long system_call + 0x80000000 + .long sysc_vtime + 0x80000000 + .long sysc_stime + 0x80000000 + .long sysc_update + 0x80000000 +#endif + +cleanup_sysc_return: + mvc __LC_RETURN_PSW(4),0(%r12) + mvc __LC_RETURN_PSW+4(4),BASED(cleanup_table_sysc_return) + la %r12,__LC_RETURN_PSW + br %r14 + +cleanup_sysc_leave: + clc 4(4,%r12),BASED(cleanup_sysc_leave_insn) + be BASED(0f) +#ifdef CONFIG_VIRT_CPU_ACCOUNTING + mvc __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER + clc 4(4,%r12),BASED(cleanup_sysc_leave_insn+4) + be BASED(0f) +#endif + mvc __LC_RETURN_PSW(8),SP_PSW(%r15) + mvc __LC_SAVE_AREA+16(16),SP_R12(%r15) + lm %r0,%r11,SP_R0(%r15) + l %r15,SP_R15(%r15) +0: la %r12,__LC_RETURN_PSW + br %r14 +cleanup_sysc_leave_insn: +#ifdef CONFIG_VIRT_CPU_ACCOUNTING + .long sysc_leave + 14 + 0x80000000 +#endif + .long sysc_leave + 10 + 0x80000000 + +/* + * Integer constants + */ + .align 4 +.Lc_spsize: .long SP_SIZE +.Lc_overhead: .long STACK_FRAME_OVERHEAD +.Lc_pactive: .long PREEMPT_ACTIVE +.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 +.Ldo_IRQ: .long do_IRQ +.Ldo_extint: .long do_extint +.Ldo_signal: .long do_signal +.Lhandle_per: .long do_single_step +.Ljump_table: .long pgm_check_table +.Lschedule: .long schedule +.Lclone: .long sys_clone +.Lexecve: .long sys_execve +.Lfork: .long sys_fork +.Lrt_sigreturn:.long sys_rt_sigreturn +.Lrt_sigsuspend: + .long sys_rt_sigsuspend +.Lsigreturn: .long sys_sigreturn +.Lsigsuspend: .long sys_sigsuspend +.Lsigaltstack: .long sys_sigaltstack +.Ltrace: .long syscall_trace +.Lvfork: .long sys_vfork +.Lschedtail: .long schedule_tail + +.Lcritical_start: + .long __critical_start + 0x80000000 +.Lcritical_end: + .long __critical_end + 0x80000000 +.Lcleanup_critical: + .long cleanup_critical + +#define SYSCALL(esa,esame,emu) .long esa + .globl sys_call_table +sys_call_table: +#include "syscalls.S" +#undef SYSCALL + |