/* * S390 low-level entry points. * * Copyright IBM Corp. 1999, 2012 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), * Hartmut Penner (hp@de.ibm.com), * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com), * Heiko Carstens */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include __PT_R0 = __PT_GPRS __PT_R1 = __PT_GPRS + 8 __PT_R2 = __PT_GPRS + 16 __PT_R3 = __PT_GPRS + 24 __PT_R4 = __PT_GPRS + 32 __PT_R5 = __PT_GPRS + 40 __PT_R6 = __PT_GPRS + 48 __PT_R7 = __PT_GPRS + 56 __PT_R8 = __PT_GPRS + 64 __PT_R9 = __PT_GPRS + 72 __PT_R10 = __PT_GPRS + 80 __PT_R11 = __PT_GPRS + 88 __PT_R12 = __PT_GPRS + 96 __PT_R13 = __PT_GPRS + 104 __PT_R14 = __PT_GPRS + 112 __PT_R15 = __PT_GPRS + 120 STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER STACK_SIZE = 1 << STACK_SHIFT STACK_INIT = STACK_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE _TIF_WORK = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \ _TIF_UPROBE) _TIF_TRACE = (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \ _TIF_SYSCALL_TRACEPOINT) _CIF_WORK = (_CIF_MCCK_PENDING | _CIF_ASCE | _CIF_FPU) _PIF_WORK = (_PIF_PER_TRAP) #define BASED(name) name-cleanup_critical(%r13) .macro TRACE_IRQS_ON #ifdef CONFIG_TRACE_IRQFLAGS basr %r2,%r0 brasl %r14,trace_hardirqs_on_caller #endif .endm .macro TRACE_IRQS_OFF #ifdef CONFIG_TRACE_IRQFLAGS basr %r2,%r0 brasl %r14,trace_hardirqs_off_caller #endif .endm .macro LOCKDEP_SYS_EXIT #ifdef CONFIG_LOCKDEP tm __PT_PSW+1(%r11),0x01 # returning to user ? jz .+10 brasl %r14,lockdep_sys_exit #endif .endm .macro CHECK_STACK stacksize,savearea #ifdef CONFIG_CHECK_STACK tml %r15,\stacksize - CONFIG_STACK_GUARD lghi %r14,\savearea jz stack_overflow #endif .endm .macro SWITCH_ASYNC savearea,timer tmhh %r8,0x0001 # interrupting from user ? jnz 1f lgr %r14,%r9 slg %r14,BASED(.Lcritical_start) clg %r14,BASED(.Lcritical_length) jhe 0f lghi %r11,\savearea # inside critical section, do cleanup brasl %r14,cleanup_critical tmhh %r8,0x0001 # retest problem state after cleanup jnz 1f 0: lg %r14,__LC_ASYNC_STACK # are we already on the async stack? slgr %r14,%r15 srag %r14,%r14,STACK_SHIFT jnz 2f CHECK_STACK 1<> 8) .if (\mask & 0xff) .error "Mask exceeds byte boundary" .endif TSTMSK \addr, "(\mask >> 8)", \size, "(\bytepos + 1)" .exitm .endif .ifeq \mask .error "Mask must not be zero" .endif off = \size - \bytepos - 1 tm off+\addr, \mask .endm .section .kprobes.text, "ax" .Ldummy: /* * This nop exists only in order to avoid that __switch_to starts at * the beginning of the kprobes text section. In that case we would * have several symbols at the same address. E.g. objdump would take * an arbitrary symbol name when disassembling this code. * With the added nop in between the __switch_to symbol is unique * again. */ nop 0 /* * Scheduler resume function, called by switch_to * gpr2 = (task_struct *) prev * gpr3 = (task_struct *) next * Returns: * gpr2 = prev */ ENTRY(__switch_to) stmg %r6,%r15,__SF_GPRS(%r15) # store gprs of prev task lgr %r1,%r2 aghi %r1,__TASK_thread # thread_struct of prev task lg %r5,__TASK_stack(%r3) # start of kernel stack of next stg %r15,__THREAD_ksp(%r1) # store kernel stack of prev lgr %r1,%r3 aghi %r1,__TASK_thread # thread_struct of next task lgr %r15,%r5 aghi %r15,STACK_INIT # end of kernel stack of next stg %r3,__LC_CURRENT # store task struct of next stg %r15,__LC_KERNEL_STACK # store end of kernel stack lg %r15,__THREAD_ksp(%r1) # load kernel stack of next /* c4 is used in guest detection: arch/s390/kernel/perf_cpum_sf.c */ lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4 mvc __LC_CURRENT_PID(4,%r0),__TASK_pid(%r3) # store pid of next lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_LPP bzr %r14 .insn s,0xb2800000,__LC_LPP # set program parameter br %r14 .L__critical_start: #if IS_ENABLED(CONFIG_KVM) /* * sie64a calling convention: * %r2 pointer to sie control block * %r3 guest register save area */ ENTRY(sie64a) stmg %r6,%r14,__SF_GPRS(%r15) # save kernel registers stg %r2,__SF_EMPTY(%r15) # save control block pointer stg %r3,__SF_EMPTY+8(%r15) # save guest register save area xc __SF_EMPTY+16(8,%r15),__SF_EMPTY+16(%r15) # reason code = 0 TSTMSK __LC_CPU_FLAGS,_CIF_FPU # load guest fp/vx registers ? jno .Lsie_load_guest_gprs brasl %r14,load_fpu_regs # load guest fp/vx regs .Lsie_load_guest_gprs: lmg %r0,%r13,0(%r3) # load guest gprs 0-13 lg %r14,__LC_GMAP # get gmap pointer ltgr %r14,%r14 jz .Lsie_gmap lctlg %c1,%c1,__GMAP_ASCE(%r14) # load primary asce .Lsie_gmap: lg %r14,__SF_EMPTY(%r15) # get control block pointer oi __SIE_PROG0C+3(%r14),1 # we are going into SIE now tm __SIE_PROG20+3(%r14),3 # last exit... jnz .Lsie_skip TSTMSK __LC_CPU_FLAGS,_CIF_FPU jo .Lsie_skip # exit if fp/vx regs changed sie 0(%r14) .Lsie_skip: ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE lctlg %c1,%c1,__LC_USER_ASCE # load primary asce .Lsie_done: # some program checks are suppressing. C code (e.g. do_protection_exception) # will rewind the PSW by the ILC, which is 4 bytes in case of SIE. Other # instructions between sie64a and .Lsie_done should not cause program # interrupts. So lets use a nop (47 00 00 00) as a landing pad. # See also .Lcleanup_sie .Lrewind_pad: nop 0 .globl sie_exit sie_exit: lg %r14,__SF_EMPTY+8(%r15) # load guest register save area stmg %r0,%r13,0(%r14) # save guest gprs 0-13 lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers lg %r2,__SF_EMPTY+16(%r15) # return exit reason code br %r14 .Lsie_fault: lghi %r14,-EFAULT stg %r14,__SF_EMPTY+16(%r15) # set exit reason code j sie_exit EX_TABLE(.Lrewind_pad,.Lsie_fault) EX_TABLE(sie_exit,.Lsie_fault) EXPORT_SYMBOL(sie64a) EXPORT_SYMBOL(sie_exit) #endif /* * SVC interrupt handler routine. System calls are synchronous events and * are executed with interrupts enabled. */ ENTRY(system_call) stpt __LC_SYNC_ENTER_TIMER .Lsysc_stmg: stmg %r8,%r15,__LC_SAVE_AREA_SYNC lg %r10,__LC_LAST_BREAK lg %r12,__LC_CURRENT lghi %r14,_PIF_SYSCALL .Lsysc_per: lg %r15,__LC_KERNEL_STACK la %r11,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs LAST_BREAK %r13 .Lsysc_vtime: UPDATE_VTIME %r10,%r13,__LC_SYNC_ENTER_TIMER stmg %r0,%r7,__PT_R0(%r11) mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC mvc __PT_PSW(16,%r11),__LC_SVC_OLD_PSW mvc __PT_INT_CODE(4,%r11),__LC_SVC_ILC stg %r14,__PT_FLAGS(%r11) .Lsysc_do_svc: lg %r10,__TI_sysc_table(%r12) # address of system call table llgh %r8,__PT_INT_CODE+2(%r11) slag %r8,%r8,2 # shift and test for svc 0 jnz .Lsysc_nr_ok # svc 0: system call number in %r1 llgfr %r1,%r1 # clear high word in r1 cghi %r1,NR_syscalls jnl .Lsysc_nr_ok sth %r1,__PT_INT_CODE+2(%r11) slag %r8,%r1,2 .Lsysc_nr_ok: xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) stg %r2,__PT_ORIG_GPR2(%r11) stg %r7,STACK_FRAME_OVERHEAD(%r15) lgf %r9,0(%r8,%r10) # get system call add. TSTMSK __TI_flags(%r12),_TIF_TRACE jnz .Lsysc_tracesys basr %r14,%r9 # call sys_xxxx stg %r2,__PT_R2(%r11) # store return value .Lsysc_return: LOCKDEP_SYS_EXIT .Lsysc_tif: TSTMSK __PT_FLAGS(%r11),_PIF_WORK jnz .Lsysc_work TSTMSK __TI_flags(%r12),_TIF_WORK jnz .Lsysc_work # check for work TSTMSK __LC_CPU_FLAGS,_CIF_WORK jnz .Lsysc_work .Lsysc_restore: lg %r14,__LC_VDSO_PER_CPU lmg %r0,%r10,__PT_R0(%r11) mvc __LC_RETURN_PSW(16),__PT_PSW(%r11) stpt __LC_EXIT_TIMER mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER lmg %r11,%r15,__PT_R11(%r11) lpswe __LC_RETURN_PSW .Lsysc_done: # # One of the work bits is on. Find out which one. # .Lsysc_work: TSTMSK __LC_CPU_FLAGS,_CIF_MCCK_PENDING jo .Lsysc_mcck_pending TSTMSK __TI_flags(%r12),_TIF_NEED_RESCHED jo .Lsysc_reschedule #ifdef CONFIG_UPROBES TSTMSK __TI_flags(%r12),_TIF_UPROBE jo .Lsysc_uprobe_notify #endif TSTMSK __PT_FLAGS(%r11),_PIF_PER_TRAP jo .Lsysc_singlestep TSTMSK __TI_flags(%r12),_TIF_SIGPENDING jo .Lsysc_sigpending TSTMSK __TI_flags(%r12),_TIF_NOTIFY_RESUME jo .Lsysc_notify_resume TSTMSK __LC_CPU_FLAGS,_CIF_FPU jo .Lsysc_vxrs TSTMSK __LC_CPU_FLAGS,_CIF_ASCE jo .Lsysc_uaccess j .Lsysc_return # beware of critical section cleanup # # _TIF_NEED_RESCHED is set, call schedule # .Lsysc_reschedule: larl %r14,.Lsysc_return jg schedule # # _CIF_MCCK_PENDING is set, call handler # .Lsysc_mcck_pending: larl %r14,.Lsysc_return jg s390_handle_mcck # TIF bit will be cleared by handler # # _CIF_ASCE is set, load user space asce # .Lsysc_uaccess: ni __LC_CPU_FLAGS+7,255-_CIF_ASCE lctlg %c1,%c1,__LC_USER_ASCE # load primary asce j .Lsysc_return # # CIF_FPU is set, restore floating-point controls and floating-point registers. # .Lsysc_vxrs: larl %r14,.Lsysc_return jg load_fpu_regs # # _TIF_SIGPENDING is set, call do_signal # .Lsysc_sigpending: lgr %r2,%r11 # pass pointer to pt_regs brasl %r14,do_signal TSTMSK __PT_FLAGS(%r11),_PIF_SYSCALL jno .Lsysc_return lmg %r2,%r7,__PT_R2(%r11) # load svc arguments lg %r10,__TI_sysc_table(%r12) # address of system call table lghi %r8,0 # svc 0 returns -ENOSYS llgh %r1,__PT_INT_CODE+2(%r11) # load new svc number cghi %r1,NR_syscalls jnl .Lsysc_nr_ok # invalid svc number -> do svc 0 slag %r8,%r1,2 j .Lsysc_nr_ok # restart svc # # _TIF_NOTIFY_RESUME is set, call do_notify_resume # .Lsysc_notify_resume: lgr %r2,%r11 # pass pointer to pt_regs larl %r14,.Lsysc_return jg do_notify_resume # # _TIF_UPROBE is set, call uprobe_notify_resume # #ifdef CONFIG_UPROBES .Lsysc_uprobe_notify: lgr %r2,%r11 # pass pointer to pt_regs larl %r14,.Lsysc_return jg uprobe_notify_resume #endif # # _PIF_PER_TRAP is set, call do_per_trap # .Lsysc_singlestep: ni __PT_FLAGS+7(%r11),255-_PIF_PER_TRAP lgr %r2,%r11 # pass pointer to pt_regs larl %r14,.Lsysc_return jg do_per_trap # # call tracehook_report_syscall_entry/tracehook_report_syscall_exit before # and after the system call # .Lsysc_tracesys: lgr %r2,%r11 # pass pointer to pt_regs la %r3,0 llgh %r0,__PT_INT_CODE+2(%r11) stg %r0,__PT_R2(%r11) brasl %r14,do_syscall_trace_enter lghi %r0,NR_syscalls clgr %r0,%r2 jnh .Lsysc_tracenogo sllg %r8,%r2,2 lgf %r9,0(%r8,%r10) .Lsysc_tracego: lmg %r3,%r7,__PT_R3(%r11) stg %r7,STACK_FRAME_OVERHEAD(%r15) lg %r2,__PT_ORIG_GPR2(%r11) basr %r14,%r9 # call sys_xxx stg %r2,__PT_R2(%r11) # store return value .Lsysc_tracenogo: TSTMSK __TI_flags(%r12),_TIF_TRACE jz .Lsysc_return lgr %r2,%r11 # pass pointer to pt_regs larl %r14,.Lsysc_return jg do_syscall_trace_exit # # a new process exits the kernel with ret_from_fork # ENTRY(ret_from_fork) la %r11,STACK_FRAME_OVERHEAD(%r15) lg %r12,__LC_CURRENT brasl %r14,schedule_tail TRACE_IRQS_ON ssm __LC_SVC_NEW_PSW # reenable interrupts tm __PT_PSW+1(%r11),0x01 # forking a kernel thread ? jne .Lsysc_tracenogo # it's a kernel thread lmg %r9,%r10,__PT_R9(%r11) # load gprs ENTRY(kernel_thread_starter) la %r2,0(%r10) basr %r14,%r9 j .Lsysc_tracenogo /* * Program check handler routine */ ENTRY(pgm_check_handler) stpt __LC_SYNC_ENTER_TIMER stmg %r8,%r15,__LC_SAVE_AREA_SYNC lg %r10,__LC_LAST_BREAK lg %r12,__LC_CURRENT larl %r13,cleanup_critical lmg %r8,%r9,__LC_PGM_OLD_PSW tmhh %r8,0x0001 # test problem state bit jnz 2f # -> fault in user space #if IS_ENABLED(CONFIG_KVM) # cleanup critical section for sie64a lgr %r14,%r9 slg %r14,BASED(.Lsie_critical_start) clg %r14,BASED(.Lsie_critical_length) jhe 0f brasl %r14,.Lcleanup_sie #endif 0: tmhh %r8,0x4000 # PER bit set in old PSW ? jnz 1f # -> enabled, can't be a double fault tm __LC_PGM_ILC+3,0x80 # check for per exception jnz .Lpgm_svcper # -> single stepped svc 1: CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) j 3f 2: LAST_BREAK %r14 UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER lg %r15,__LC_KERNEL_STACK lgr %r14,%r12 aghi %r14,__TASK_thread # pointer to thread_struct lghi %r13,__LC_PGM_TDB tm __LC_PGM_ILC+2,0x02 # check for transaction abort jz 3f mvc __THREAD_trap_tdb(256,%r14),0(%r13) 3: la %r11,STACK_FRAME_OVERHEAD(%r15) stmg %r0,%r7,__PT_R0(%r11) mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC stmg %r8,%r9,__PT_PSW(%r11) mvc __PT_INT_CODE(4,%r11),__LC_PGM_ILC mvc __PT_INT_PARM_LONG(8,%r11),__LC_TRANS_EXC_CODE xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11) stg %r10,__PT_ARGS(%r11) tm __LC_PGM_ILC+3,0x80 # check for per exception jz 4f tmhh %r8,0x0001 # kernel per event ? jz .Lpgm_kprobe oi __PT_FLAGS+7(%r11),_PIF_PER_TRAP mvc __THREAD_per_address(8,%r14),__LC_PER_ADDRESS mvc __THREAD_per_cause(2,%r14),__LC_PER_CODE mvc __THREAD_per_paid(1,%r14),__LC_PER_ACCESS_ID 4: REENABLE_IRQS xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) larl %r1,pgm_check_table llgh %r10,__PT_INT_CODE+2(%r11) nill %r10,0x007f sll %r10,2 je .Lpgm_return lgf %r1,0(%r10,%r1) # load address of handler routine lgr %r2,%r11 # pass pointer to pt_regs basr %r14,%r1 # branch to interrupt-handler .Lpgm_return: LOCKDEP_SYS_EXIT tm __PT_PSW+1(%r11),0x01 # returning to user ? jno .Lsysc_restore j .Lsysc_tif # # PER event in supervisor state, must be kprobes # .Lpgm_kprobe: REENABLE_IRQS xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) lgr %r2,%r11 # pass pointer to pt_regs brasl %r14,do_per_trap j .Lpgm_return # # single stepped system call # .Lpgm_svcper: mvc __LC_RETURN_PSW(8),__LC_SVC_NEW_PSW larl %r14,.Lsysc_per stg %r14,__LC_RETURN_PSW+8 lghi %r14,_PIF_SYSCALL | _PIF_PER_TRAP lpswe __LC_RETURN_PSW # branch to .Lsysc_per and enable irqs /* * IO interrupt handler routine */ ENTRY(io_int_handler) STCK __LC_INT_CLOCK stpt __LC_ASYNC_ENTER_TIMER stmg %r8,%r15,__LC_SAVE_AREA_ASYNC lg %r10,__LC_LAST_BREAK lg %r12,__LC_CURRENT larl %r13,cleanup_critical lmg %r8,%r9,__LC_IO_OLD_PSW SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER stmg %r0,%r7,__PT_R0(%r11) mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC stmg %r8,%r9,__PT_PSW(%r11) mvc __PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11) TSTMSK __LC_CPU_FLAGS,_CIF_IGNORE_IRQ jo .Lio_restore TRACE_IRQS_OFF xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) .Lio_loop: lgr %r2,%r11 # pass pointer to pt_regs lghi %r3,IO_INTERRUPT tm __PT_INT_CODE+8(%r11),0x80 # adapter interrupt ? jz .Lio_call lghi %r3,THIN_INTERRUPT .Lio_call: brasl %r14,do_IRQ TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_LPAR jz .Lio_return tpi 0 jz .Lio_return mvc __PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID j .Lio_loop .Lio_return: LOCKDEP_SYS_EXIT TRACE_IRQS_ON .Lio_tif: TSTMSK __TI_flags(%r12),_TIF_WORK jnz .Lio_work # there is work to do (signals etc.) TSTMSK __LC_CPU_FLAGS,_CIF_WORK jnz .Lio_work .Lio_restore: lg %r14,__LC_VDSO_PER_CPU lmg %r0,%r10,__PT_R0(%r11) mvc __LC_RETURN_PSW(16),__PT_PSW(%r11) stpt __LC_EXIT_TIMER mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER lmg %r11,%r15,__PT_R11(%r11) lpswe __LC_RETURN_PSW .Lio_done: # # There is work todo, find out in which context we have been interrupted: # 1) if we return to user space we can do all _TIF_WORK work # 2) if we return to kernel code and kvm is enabled check if we need to # modify the psw to leave SIE # 3) if we return to kernel code and preemptive scheduling is enabled check # the preemption counter and if it is zero call preempt_schedule_irq # Before any work can be done, a switch to the kernel stack is required. # .Lio_work: tm __PT_PSW+1(%r11),0x01 # returning to user ? jo .Lio_work_user # yes -> do resched & signal #ifdef CONFIG_PREEMPT # check for preemptive scheduling icm %r0,15,__LC_PREEMPT_COUNT jnz .Lio_restore # preemption is disabled TSTMSK __TI_flags(%r12),_TIF_NEED_RESCHED jno .Lio_restore # switch to kernel stack lg %r1,__PT_R15(%r11) aghi %r1,-(STACK_FRAME_OVERHEAD + __PT_SIZE) mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11) xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) la %r11,STACK_FRAME_OVERHEAD(%r1) lgr %r15,%r1 # TRACE_IRQS_ON already done at .Lio_return, call # TRACE_IRQS_OFF to keep things symmetrical TRACE_IRQS_OFF brasl %r14,preempt_schedule_irq j .Lio_return #else j .Lio_restore #endif # # Need to do work before returning to userspace, switch to kernel stack # .Lio_work_user: lg %r1,__LC_KERNEL_STACK mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11) xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) la %r11,STACK_FRAME_OVERHEAD(%r1) lgr %r15,%r1 # # One of the work bits is on. Find out which one. # .Lio_work_tif: TSTMSK __LC_CPU_FLAGS,_CIF_MCCK_PENDING jo .Lio_mcck_pending TSTMSK __TI_flags(%r12),_TIF_NEED_RESCHED jo .Lio_reschedule TSTMSK __TI_flags(%r12),_TIF_SIGPENDING jo .Lio_sigpending TSTMSK __TI_flags(%r12),_TIF_NOTIFY_RESUME jo .Lio_notify_resume TSTMSK __LC_CPU_FLAGS,_CIF_FPU jo .Lio_vxrs TSTMSK __LC_CPU_FLAGS,_CIF_ASCE jo .Lio_uaccess j .Lio_return # beware of critical section cleanup # # _CIF_MCCK_PENDING is set, call handler # .Lio_mcck_pending: # TRACE_IRQS_ON already done at .Lio_return brasl %r14,s390_handle_mcck # TIF bit will be cleared by handler TRACE_IRQS_OFF j .Lio_return # # _CIF_ASCE is set, load user space asce # .Lio_uaccess: ni __LC_CPU_FLAGS+7,255-_CIF_ASCE lctlg %c1,%c1,__LC_USER_ASCE # load primary asce j .Lio_return # # CIF_FPU is set, restore floating-point controls and floating-point registers. # .Lio_vxrs: larl %r14,.Lio_return jg load_fpu_regs # # _TIF_NEED_RESCHED is set, call schedule # .Lio_reschedule: # TRACE_IRQS_ON already done at .Lio_return ssm __LC_SVC_NEW_PSW # reenable interrupts brasl %r14,schedule # call scheduler ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts TRACE_IRQS_OFF j .Lio_return # # _TIF_SIGPENDING or is set, call do_signal # .Lio_sigpending: # TRACE_IRQS_ON already done at .Lio_return ssm __LC_SVC_NEW_PSW # reenable interrupts lgr %r2,%r11 # pass pointer to pt_regs brasl %r14,do_signal ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts TRACE_IRQS_OFF j .Lio_return # # _TIF_NOTIFY_RESUME or is set, call do_notify_resume # .Lio_notify_resume: # TRACE_IRQS_ON already done at .Lio_return ssm __LC_SVC_NEW_PSW # reenable interrupts lgr %r2,%r11 # pass pointer to pt_regs brasl %r14,do_notify_resume ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts TRACE_IRQS_OFF j .Lio_return /* * External interrupt handler routine */ ENTRY(ext_int_handler) STCK __LC_INT_CLOCK stpt __LC_ASYNC_ENTER_TIMER stmg %r8,%r15,__LC_SAVE_AREA_ASYNC lg %r10,__LC_LAST_BREAK lg %r12,__LC_CURRENT larl %r13,cleanup_critical lmg %r8,%r9,__LC_EXT_OLD_PSW SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER stmg %r0,%r7,__PT_R0(%r11) mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC stmg %r8,%r9,__PT_PSW(%r11) lghi %r1,__LC_EXT_PARAMS2 mvc __PT_INT_CODE(4,%r11),__LC_EXT_CPU_ADDR mvc __PT_INT_PARM(4,%r11),__LC_EXT_PARAMS mvc __PT_INT_PARM_LONG(8,%r11),0(%r1) xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11) TSTMSK __LC_CPU_FLAGS,_CIF_IGNORE_IRQ jo .Lio_restore TRACE_IRQS_OFF xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) lgr %r2,%r11 # pass pointer to pt_regs lghi %r3,EXT_INTERRUPT brasl %r14,do_IRQ j .Lio_return /* * Load idle PSW. The second "half" of this function is in .Lcleanup_idle. */ ENTRY(psw_idle) stg %r3,__SF_EMPTY(%r15) larl %r1,.Lpsw_idle_lpsw+4 stg %r1,__SF_EMPTY+8(%r15) #ifdef CONFIG_SMP larl %r1,smp_cpu_mtid llgf %r1,0(%r1) ltgr %r1,%r1 jz .Lpsw_idle_stcctm .insn rsy,0xeb0000000017,%r1,5,__SF_EMPTY+16(%r15) .Lpsw_idle_stcctm: #endif oi __LC_CPU_FLAGS+7,_CIF_ENABLED_WAIT STCK __CLOCK_IDLE_ENTER(%r2) stpt __TIMER_IDLE_ENTER(%r2) .Lpsw_idle_lpsw: lpswe __SF_EMPTY(%r15) br %r14 .Lpsw_idle_end: /* * Store floating-point controls and floating-point or vector register * depending whether the vector facility is available. A critical section * cleanup assures that the registers are stored even if interrupted for * some other work. The CIF_FPU flag is set to trigger a lazy restore * of the register contents at return from io or a system call. */ ENTRY(save_fpu_regs) lg %r2,__LC_CURRENT aghi %r2,__TASK_thread TSTMSK __LC_CPU_FLAGS,_CIF_FPU bor %r14 stfpc __THREAD_FPU_fpc(%r2) .Lsave_fpu_regs_fpc_end: lg %r3,__THREAD_FPU_regs(%r2) TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_VX jz .Lsave_fpu_regs_fp # no -> store FP regs .Lsave_fpu_regs_vx_low: VSTM %v0,%v15,0,%r3 # vstm 0,15,0(3) .Lsave_fpu_regs_vx_high: VSTM %v16,%v31,256,%r3 # vstm 16,31,256(3) j .Lsave_fpu_regs_done # -> set CIF_FPU flag .Lsave_fpu_regs_fp: std 0,0(%r3) std 1,8(%r3) std 2,16(%r3) std 3,24(%r3) std 4,32(%r3) std 5,40(%r3) std 6,48(%r3) std 7,56(%r3) std 8,64(%r3) std 9,72(%r3) std 10,80(%r3) std 11,88(%r3) std 12,96(%r3) std 13,104(%r3) std 14,112(%r3) std 15,120(%r3) .Lsave_fpu_regs_done: oi __LC_CPU_FLAGS+7,_CIF_FPU br %r14 .Lsave_fpu_regs_end: #if IS_ENABLED(CONFIG_KVM) EXPORT_SYMBOL(save_fpu_regs) #endif /* * Load floating-point controls and floating-point or vector registers. * A critical section cleanup assures that the register contents are * loaded even if interrupted for some other work. * * There are special calling conventions to fit into sysc and io return work: * %r15: * The function requires: * %r4 */ load_fpu_regs: lg %r4,__LC_CURRENT aghi %r4,__TASK_thread TSTMSK __LC_CPU_FLAGS,_CIF_FPU bnor %r14 lfpc __THREAD_FPU_fpc(%r4) TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_VX lg %r4,__THREAD_FPU_regs(%r4) # %r4 <- reg save area jz .Lload_fpu_regs_fp # -> no VX, load FP regs .Lload_fpu_regs_vx: VLM %v0,%v15,0,%r4 .Lload_fpu_regs_vx_high: VLM %v16,%v31,256,%r4 j .Lload_fpu_regs_done .Lload_fpu_regs_fp: ld 0,0(%r4) ld 1,8(%r4) ld 2,16(%r4) ld 3,24(%r4) ld 4,32(%r4) ld 5,40(%r4) ld 6,48(%r4) ld 7,56(%r4) ld 8,64(%r4) ld 9,72(%r4) ld 10,80(%r4) ld 11,88(%r4) ld 12,96(%r4) ld 13,104(%r4) ld 14,112(%r4) ld 15,120(%r4) .Lload_fpu_regs_done: ni __LC_CPU_FLAGS+7,255-_CIF_FPU br %r14 .Lload_fpu_regs_end: .L__critical_end: /* * Machine check handler routines */ ENTRY(mcck_int_handler) STCK __LC_MCCK_CLOCK la %r1,4095 # revalidate r1 spt __LC_CPU_TIMER_SAVE_AREA-4095(%r1) # revalidate cpu timer lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# revalidate gprs lg %r10,__LC_LAST_BREAK lg %r12,__LC_CURRENT larl %r13,cleanup_critical lmg %r8,%r9,__LC_MCK_OLD_PSW TSTMSK __LC_MCCK_CODE,MCCK_CODE_SYSTEM_DAMAGE jo .Lmcck_panic # yes -> rest of mcck code invalid lghi %r14,__LC_CPU_TIMER_SAVE_AREA mvc __LC_MCCK_ENTER_TIMER(8),0(%r14) TSTMSK __LC_MCCK_CODE,MCCK_CODE_CPU_TIMER_VALID jo 3f la %r14,__LC_SYNC_ENTER_TIMER clc 0(8,%r14),__LC_ASYNC_ENTER_TIMER jl 0f la %r14,__LC_ASYNC_ENTER_TIMER 0: clc 0(8,%r14),__LC_EXIT_TIMER jl 1f la %r14,__LC_EXIT_TIMER 1: clc 0(8,%r14),__LC_LAST_UPDATE_TIMER jl 2f la %r14,__LC_LAST_UPDATE_TIMER 2: spt 0(%r14) mvc __LC_MCCK_ENTER_TIMER(8),0(%r14) 3: TSTMSK __LC_MCCK_CODE,(MCCK_CODE_PSW_MWP_VALID|MCCK_CODE_PSW_IA_VALID) jno .Lmcck_panic # no -> skip cleanup critical SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_MCCK_ENTER_TIMER .Lmcck_skip: lghi %r14,__LC_GPREGS_SAVE_AREA+64 stmg %r0,%r7,__PT_R0(%r11) mvc __PT_R8(64,%r11),0(%r14) stmg %r8,%r9,__PT_PSW(%r11) xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11) xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) lgr %r2,%r11 # pass pointer to pt_regs brasl %r14,s390_do_machine_check tm __PT_PSW+1(%r11),0x01 # returning to user ? jno .Lmcck_return lg %r1,__LC_KERNEL_STACK # switch to kernel stack mvc STACK_FRAME_OVERHEAD(__PT_SIZE,%r1),0(%r11) xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) la %r11,STACK_FRAME_OVERHEAD(%r1) lgr %r15,%r1 ssm __LC_PGM_NEW_PSW # turn dat on, keep irqs off TSTMSK __LC_CPU_FLAGS,_CIF_MCCK_PENDING jno .Lmcck_return TRACE_IRQS_OFF brasl %r14,s390_handle_mcck TRACE_IRQS_ON .Lmcck_return: lg %r14,__LC_VDSO_PER_CPU lmg %r0,%r10,__PT_R0(%r11) mvc __LC_RETURN_MCCK_PSW(16),__PT_PSW(%r11) # move return PSW tm __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ? jno 0f stpt __LC_EXIT_TIMER mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER 0: lmg %r11,%r15,__PT_R11(%r11) lpswe __LC_RETURN_MCCK_PSW .Lmcck_panic: lg %r15,__LC_PANIC_STACK aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) j .Lmcck_skip # # PSW restart interrupt handler # ENTRY(restart_int_handler) TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_LPP jz 0f .insn s,0xb2800000,__LC_LPP 0: stg %r15,__LC_SAVE_AREA_RESTART lg %r15,__LC_RESTART_STACK aghi %r15,-__PT_SIZE # create pt_regs on stack xc 0(__PT_SIZE,%r15),0(%r15) stmg %r0,%r14,__PT_R0(%r15) mvc __PT_R15(8,%r15),__LC_SAVE_AREA_RESTART mvc __PT_PSW(16,%r15),__LC_RST_OLD_PSW # store restart old psw aghi %r15,-STACK_FRAME_OVERHEAD # create stack frame on stack xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15) lg %r1,__LC_RESTART_FN # load fn, parm & source cpu lg %r2,__LC_RESTART_DATA lg %r3,__LC_RESTART_SOURCE ltgr %r3,%r3 # test source cpu address jm 1f # negative -> skip source stop 0: sigp %r4,%r3,SIGP_SENSE # sigp sense to source cpu brc 10,0b # wait for status stored 1: basr %r14,%r1 # call function stap __SF_EMPTY(%r15) # store cpu address llgh %r3,__SF_EMPTY(%r15) 2: sigp %r4,%r3,SIGP_STOP # sigp stop to current cpu brc 2,2b 3: j 3b .section .kprobes.text, "ax" #ifdef CONFIG_CHECK_STACK /* * The synchronous or the asynchronous stack overflowed. We are dead. * No need to properly save the registers, we are going to panic anyway. * Setup a pt_regs so that show_trace can provide a good call trace. */ stack_overflow: lg %r15,__LC_PANIC_STACK # change to panic stack la %r11,STACK_FRAME_OVERHEAD(%r15) stmg %r0,%r7,__PT_R0(%r11) stmg %r8,%r9,__PT_PSW(%r11) mvc __PT_R8(64,%r11),0(%r14) stg %r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) lgr %r2,%r11 # pass pointer to pt_regs jg kernel_stack_overflow #endif cleanup_critical: #if IS_ENABLED(CONFIG_KVM) clg %r9,BASED(.Lcleanup_table_sie) # .Lsie_gmap jl 0f clg %r9,BASED(.Lcleanup_table_sie+8)# .Lsie_done jl .Lcleanup_sie #endif clg %r9,BASED(.Lcleanup_table) # system_call jl 0f clg %r9,BASED(.Lcleanup_table+8) # .Lsysc_do_svc jl .Lcleanup_system_call clg %r9,BASED(.Lcleanup_table+16) # .Lsysc_tif jl 0f clg %r9,BASED(.Lcleanup_table+24) # .Lsysc_restore jl .Lcleanup_sysc_tif clg %r9,BASED(.Lcleanup_table+32) # .Lsysc_done jl .Lcleanup_sysc_restore clg %r9,BASED(.Lcleanup_table+40) # .Lio_tif jl 0f clg %r9,BASED(.Lcleanup_table+48) # .Lio_restore jl .Lcleanup_io_tif clg %r9,BASED(.Lcleanup_table+56) # .Lio_done jl .Lcleanup_io_restore clg %r9,BASED(.Lcleanup_table+64) # psw_idle jl 0f clg %r9,BASED(.Lcleanup_table+72) # .Lpsw_idle_end jl .Lcleanup_idle clg %r9,BASED(.Lcleanup_table+80) # save_fpu_regs jl 0f clg %r9,BASED(.Lcleanup_table+88) # .Lsave_fpu_regs_end jl .Lcleanup_save_fpu_regs clg %r9,BASED(.Lcleanup_table+96) # load_fpu_regs jl 0f clg %r9,BASED(.Lcleanup_table+104) # .Lload_fpu_regs_end jl .Lcleanup_load_fpu_regs 0: br %r14 .align 8 .Lcleanup_table: .quad system_call .quad .Lsysc_do_svc .quad .Lsysc_tif .quad .Lsysc_restore .quad .Lsysc_done .quad .Lio_tif .quad .Lio_restore .quad .Lio_done .quad psw_idle .quad .Lpsw_idle_end .quad save_fpu_regs .quad .Lsave_fpu_regs_end .quad load_fpu_regs .quad .Lload_fpu_regs_end #if IS_ENABLED(CONFIG_KVM) .Lcleanup_table_sie: .quad .Lsie_gmap .quad .Lsie_done .Lcleanup_sie: lg %r9,__SF_EMPTY(%r15) # get control block pointer ni __SIE_PROG0C+3(%r9),0xfe # no longer in SIE lctlg %c1,%c1,__LC_USER_ASCE # load primary asce larl %r9,sie_exit # skip forward to sie_exit br %r14 #endif .Lcleanup_system_call: # check if stpt has been executed clg %r9,BASED(.Lcleanup_system_call_insn) jh 0f mvc __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER cghi %r11,__LC_SAVE_AREA_ASYNC je 0f mvc __LC_SYNC_ENTER_TIMER(8),__LC_MCCK_ENTER_TIMER 0: # check if stmg has been executed clg %r9,BASED(.Lcleanup_system_call_insn+8) jh 0f mvc __LC_SAVE_AREA_SYNC(64),0(%r11) 0: # check if base register setup + TIF bit load has been done clg %r9,BASED(.Lcleanup_system_call_insn+16) jhe 0f # set up saved registers r10 and r12 stg %r10,16(%r11) # r10 last break stg %r12,32(%r11) # r12 thread-info pointer 0: # check if the user time update has been done clg %r9,BASED(.Lcleanup_system_call_insn+24) jh 0f lg %r15,__LC_EXIT_TIMER slg %r15,__LC_SYNC_ENTER_TIMER alg %r15,__LC_USER_TIMER stg %r15,__LC_USER_TIMER 0: # check if the system time update has been done clg %r9,BASED(.Lcleanup_system_call_insn+32) jh 0f lg %r15,__LC_LAST_UPDATE_TIMER slg %r15,__LC_EXIT_TIMER alg %r15,__LC_SYSTEM_TIMER stg %r15,__LC_SYSTEM_TIMER 0: # update accounting time stamp mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER # do LAST_BREAK lg %r9,16(%r11) srag %r9,%r9,23 jz 0f mvc __TI_last_break(8,%r12),16(%r11) 0: # set up saved register r11 lg %r15,__LC_KERNEL_STACK la %r9,STACK_FRAME_OVERHEAD(%r15) stg %r9,24(%r11) # r11 pt_regs pointer # fill pt_regs mvc __PT_R8(64,%r9),__LC_SAVE_AREA_SYNC stmg %r0,%r7,__PT_R0(%r9) mvc __PT_PSW(16,%r9),__LC_SVC_OLD_PSW mvc __PT_INT_CODE(4,%r9),__LC_SVC_ILC xc __PT_FLAGS(8,%r9),__PT_FLAGS(%r9) mvi __PT_FLAGS+7(%r9),_PIF_SYSCALL # setup saved register r15 stg %r15,56(%r11) # r15 stack pointer # set new psw address and exit larl %r9,.Lsysc_do_svc br %r14 .Lcleanup_system_call_insn: .quad system_call .quad .Lsysc_stmg .quad .Lsysc_per .quad .Lsysc_vtime+36 .quad .Lsysc_vtime+42 .Lcleanup_sysc_tif: larl %r9,.Lsysc_tif br %r14 .Lcleanup_sysc_restore: clg %r9,BASED(.Lcleanup_sysc_restore_insn) je 0f lg %r9,24(%r11) # get saved pointer to pt_regs mvc __LC_RETURN_PSW(16),__PT_PSW(%r9) mvc 0(64,%r11),__PT_R8(%r9) lmg %r0,%r7,__PT_R0(%r9) 0: lmg %r8,%r9,__LC_RETURN_PSW br %r14 .Lcleanup_sysc_restore_insn: .quad .Lsysc_done - 4 .Lcleanup_io_tif: larl %r9,.Lio_tif br %r14 .Lcleanup_io_restore: clg %r9,BASED(.Lcleanup_io_restore_insn) je 0f lg %r9,24(%r11) # get saved r11 pointer to pt_regs mvc __LC_RETURN_PSW(16),__PT_PSW(%r9) mvc 0(64,%r11),__PT_R8(%r9) lmg %r0,%r7,__PT_R0(%r9) 0: lmg %r8,%r9,__LC_RETURN_PSW br %r14 .Lcleanup_io_restore_insn: .quad .Lio_done - 4 .Lcleanup_idle: ni __LC_CPU_FLAGS+7,255-_CIF_ENABLED_WAIT # copy interrupt clock & cpu timer mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_INT_CLOCK mvc __TIMER_IDLE_EXIT(8,%r2),__LC_ASYNC_ENTER_TIMER cghi %r11,__LC_SAVE_AREA_ASYNC je 0f mvc __CLOCK_IDLE_EXIT(8,%r2),__LC_MCCK_CLOCK mvc __TIMER_IDLE_EXIT(8,%r2),__LC_MCCK_ENTER_TIMER 0: # check if stck & stpt have been executed clg %r9,BASED(.Lcleanup_idle_insn) jhe 1f mvc __CLOCK_IDLE_ENTER(8,%r2),__CLOCK_IDLE_EXIT(%r2) mvc __TIMER_IDLE_ENTER(8,%r2),__TIMER_IDLE_EXIT(%r2) 1: # calculate idle cycles #ifdef CONFIG_SMP clg %r9,BASED(.Lcleanup_idle_insn) jl 3f larl %r1,smp_cpu_mtid llgf %r1,0(%r1) ltgr %r1,%r1 jz 3f .insn rsy,0xeb0000000017,%r1,5,__SF_EMPTY+80(%r15) larl %r3,mt_cycles ag %r3,__LC_PERCPU_OFFSET la %r4,__SF_EMPTY+16(%r15) 2: lg %r0,0(%r3) slg %r0,0(%r4) alg %r0,64(%r4) stg %r0,0(%r3) la %r3,8(%r3) la %r4,8(%r4) brct %r1,2b #endif 3: # account system time going idle lg %r9,__LC_STEAL_TIMER alg %r9,__CLOCK_IDLE_ENTER(%r2) slg %r9,__LC_LAST_UPDATE_CLOCK stg %r9,__LC_STEAL_TIMER mvc __LC_LAST_UPDATE_CLOCK(8),__CLOCK_IDLE_EXIT(%r2) lg %r9,__LC_SYSTEM_TIMER alg %r9,__LC_LAST_UPDATE_TIMER slg %r9,__TIMER_IDLE_ENTER(%r2) stg %r9,__LC_SYSTEM_TIMER mvc __LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2) # prepare return psw nihh %r8,0xfcfd # clear irq & wait state bits lg %r9,48(%r11) # return from psw_idle br %r14 .Lcleanup_idle_insn: .quad .Lpsw_idle_lpsw .Lcleanup_save_fpu_regs: larl %r9,save_fpu_regs br %r14 .Lcleanup_load_fpu_regs: larl %r9,load_fpu_regs br %r14 /* * Integer constants */ .align 8 .Lcritical_start: .quad .L__critical_start .Lcritical_length: .quad .L__critical_end - .L__critical_start #if IS_ENABLED(CONFIG_KVM) .Lsie_critical_start: .quad .Lsie_gmap .Lsie_critical_length: .quad .Lsie_done - .Lsie_gmap #endif .section .rodata, "a" #define SYSCALL(esame,emu) .long esame .globl sys_call_table sys_call_table: #include "syscalls.S" #undef SYSCALL #ifdef CONFIG_COMPAT #define SYSCALL(esame,emu) .long emu .globl sys_call_table_emu sys_call_table_emu: #include "syscalls.S" #undef SYSCALL #endif