/* * 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 */ #include #include #include #include #include #include #include #include #include /* * 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+48(%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+48(%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