/* * 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 <heiko.carstens@de.ibm.com> */ #include <linux/init.h> #include <linux/linkage.h> #include <asm/processor.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> #include <asm/sigp.h> #include <asm/irq.h> __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) _PIF_WORK = (_PIF_PER_TRAP) #define BASED(name) name-system_call(%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 LPP newpp #if IS_ENABLED(CONFIG_KVM) tm __LC_MACHINE_FLAGS+6,0x20 # MACHINE_FLAG_LPP jz .+8 .insn s,0xb2800000,\newpp #endif .endm .macro HANDLE_SIE_INTERCEPT scratch,reason #if IS_ENABLED(CONFIG_KVM) tmhh %r8,0x0001 # interrupting from user ? jnz .+62 lgr \scratch,%r9 slg \scratch,BASED(.Lsie_critical) clg \scratch,BASED(.Lsie_critical_length) .if \reason==1 # Some program interrupts are suppressing (e.g. protection). # We must also check the instruction after SIE in that case. # do_protection_exception will rewind to rewind_pad jh .+42 .else jhe .+42 .endif lg %r14,__SF_EMPTY(%r15) # get control block pointer LPP __SF_EMPTY+16(%r15) # set host id ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE lctlg %c1,%c1,__LC_USER_ASCE # load primary asce larl %r9,sie_exit # skip forward to sie_exit mvi __SF_EMPTY+31(%r15),\reason # set exit reason #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,stack,shift 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,\stack # are we already on the target stack? slgr %r14,%r15 srag %r14,%r14,\shift jnz 1f CHECK_STACK 1<<\shift,\savearea aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) j 2f 1: lg %r15,\stack # load target stack 2: la %r11,STACK_FRAME_OVERHEAD(%r15) .endm .macro UPDATE_VTIME scratch,enter_timer lg \scratch,__LC_EXIT_TIMER slg \scratch,\enter_timer alg \scratch,__LC_USER_TIMER stg \scratch,__LC_USER_TIMER lg \scratch,__LC_LAST_UPDATE_TIMER slg \scratch,__LC_EXIT_TIMER alg \scratch,__LC_SYSTEM_TIMER stg \scratch,__LC_SYSTEM_TIMER mvc __LC_LAST_UPDATE_TIMER(8),\enter_timer .endm .macro LAST_BREAK scratch srag \scratch,%r10,23 jz .+10 stg %r10,__TI_last_break(%r12) .endm .macro REENABLE_IRQS stg %r8,__LC_RETURN_PSW ni __LC_RETURN_PSW,0xbf ssm __LC_RETURN_PSW .endm .macro STCK savearea #ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES .insn s,0xb27c0000,\savearea # store clock fast #else .insn s,0xb2050000,\savearea # store clock #endif .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) stmg %r6,%r15,__SF_GPRS(%r15) # store gprs of prev task stg %r15,__THREAD_ksp(%r2) # store kernel stack of prev lg %r4,__THREAD_info(%r2) # get thread_info of prev lg %r5,__THREAD_info(%r3) # get thread_info of next lgr %r15,%r5 aghi %r15,STACK_INIT # end of kernel stack of next stg %r3,__LC_CURRENT # store task struct of next stg %r5,__LC_THREAD_INFO # store thread info of next stg %r15,__LC_KERNEL_STACK # store end of kernel stack lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4 mvc __LC_CURRENT_PID+4(4,%r0),__TASK_pid(%r3) # store pid of next lg %r15,__THREAD_ksp(%r3) # load kernel stack of next lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task 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_stmg: stmg %r8,%r15,__LC_SAVE_AREA_SYNC lg %r10,__LC_LAST_BREAK lg %r12,__LC_THREAD_INFO lghi %r14,_PIF_SYSCALL sysc_per: lg %r15,__LC_KERNEL_STACK la %r11,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs sysc_vtime: UPDATE_VTIME %r13,__LC_SYNC_ENTER_TIMER LAST_BREAK %r13 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) sysc_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 sysc_nr_ok # svc 0: system call number in %r1 llgfr %r1,%r1 # clear high word in r1 cghi %r1,NR_syscalls jnl sysc_nr_ok sth %r1,__PT_INT_CODE+2(%r11) slag %r8,%r1,2 sysc_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. tm __TI_flags+7(%r12),_TIF_TRACE jnz sysc_tracesys basr %r14,%r9 # call sys_xxxx stg %r2,__PT_R2(%r11) # store return value sysc_return: LOCKDEP_SYS_EXIT sysc_tif: tm __PT_PSW+1(%r11),0x01 # returning to user ? jno sysc_restore tm __PT_FLAGS+7(%r11),_PIF_WORK jnz sysc_work tm __TI_flags+7(%r12),_TIF_WORK jnz sysc_work # check for work tm __LC_CPU_FLAGS+7,_CIF_WORK jnz sysc_work sysc_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 sysc_done: # # One of the work bits is on. Find out which one. # sysc_work: tm __LC_CPU_FLAGS+7,_CIF_MCCK_PENDING jo sysc_mcck_pending tm __TI_flags+7(%r12),_TIF_NEED_RESCHED jo sysc_reschedule #ifdef CONFIG_UPROBES tm __TI_flags+7(%r12),_TIF_UPROBE jo sysc_uprobe_notify #endif tm __PT_FLAGS+7(%r11),_PIF_PER_TRAP jo sysc_singlestep tm __TI_flags+7(%r12),_TIF_SIGPENDING jo sysc_sigpending tm __TI_flags+7(%r12),_TIF_NOTIFY_RESUME jo sysc_notify_resume tm __LC_CPU_FLAGS+7,_CIF_ASCE jo sysc_uaccess j sysc_return # beware of critical section cleanup # # _TIF_NEED_RESCHED is set, call schedule # sysc_reschedule: larl %r14,sysc_return jg schedule # # _CIF_MCCK_PENDING is set, call handler # sysc_mcck_pending: larl %r14,sysc_return jg s390_handle_mcck # TIF bit will be cleared by handler # # _CIF_ASCE is set, load user space asce # sysc_uaccess: ni __LC_CPU_FLAGS+7,255-_CIF_ASCE lctlg %c1,%c1,__LC_USER_ASCE # load primary asce j sysc_return # # _TIF_SIGPENDING is set, call do_signal # sysc_sigpending: lgr %r2,%r11 # pass pointer to pt_regs brasl %r14,do_signal tm __PT_FLAGS+7(%r11),_PIF_SYSCALL jno sysc_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 sysc_nr_ok # invalid svc number -> do svc 0 slag %r8,%r1,2 j sysc_nr_ok # restart svc # # _TIF_NOTIFY_RESUME is set, call do_notify_resume # sysc_notify_resume: lgr %r2,%r11 # pass pointer to pt_regs larl %r14,sysc_return jg do_notify_resume # # _TIF_UPROBE is set, call uprobe_notify_resume # #ifdef CONFIG_UPROBES sysc_uprobe_notify: lgr %r2,%r11 # pass pointer to pt_regs larl %r14,sysc_return jg uprobe_notify_resume #endif # # _PIF_PER_TRAP is set, call do_per_trap # sysc_singlestep: ni __PT_FLAGS+7(%r11),255-_PIF_PER_TRAP lgr %r2,%r11 # pass pointer to pt_regs larl %r14,sysc_return jg do_per_trap # # call tracehook_report_syscall_entry/tracehook_report_syscall_exit before # and after the system call # sysc_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 sysc_tracenogo sllg %r8,%r2,2 lgf %r9,0(%r8,%r10) sysc_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 sysc_tracenogo: tm __TI_flags+7(%r12),_TIF_TRACE jz sysc_return lgr %r2,%r11 # pass pointer to pt_regs larl %r14,sysc_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_THREAD_INFO 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 sysc_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 sysc_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_THREAD_INFO larl %r13,system_call lmg %r8,%r9,__LC_PGM_OLD_PSW HANDLE_SIE_INTERCEPT %r14,1 tmhh %r8,0x0001 # test problem state bit jnz 1f # -> fault in user space tmhh %r8,0x4000 # PER bit set in old PSW ? jnz 0f # -> enabled, can't be a double fault tm __LC_PGM_ILC+3,0x80 # check for per exception jnz pgm_svcper # -> single stepped svc 0: CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) j 2f 1: UPDATE_VTIME %r14,__LC_SYNC_ENTER_TIMER LAST_BREAK %r14 lg %r15,__LC_KERNEL_STACK lg %r14,__TI_task(%r12) lghi %r13,__LC_PGM_TDB tm __LC_PGM_ILC+2,0x02 # check for transaction abort jz 2f mvc __THREAD_trap_tdb(256,%r14),0(%r13) 2: 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 0f tmhh %r8,0x0001 # kernel per event ? jz pgm_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 0: 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 sysc_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 j sysc_return # # PER event in supervisor state, must be kprobes # pgm_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 sysc_return # # single stepped system call # pgm_svcper: mvc __LC_RETURN_PSW(8),__LC_SVC_NEW_PSW larl %r14,sysc_per stg %r14,__LC_RETURN_PSW+8 lghi %r14,_PIF_SYSCALL | _PIF_PER_TRAP lpswe __LC_RETURN_PSW # branch to sysc_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_THREAD_INFO larl %r13,system_call lmg %r8,%r9,__LC_IO_OLD_PSW HANDLE_SIE_INTERCEPT %r14,2 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT tmhh %r8,0x0001 # interrupting from user? jz io_skip UPDATE_VTIME %r14,__LC_ASYNC_ENTER_TIMER LAST_BREAK %r14 io_skip: 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) TRACE_IRQS_OFF xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) io_loop: lgr %r2,%r11 # pass pointer to pt_regs lghi %r3,IO_INTERRUPT tm __PT_INT_CODE+8(%r11),0x80 # adapter interrupt ? jz io_call lghi %r3,THIN_INTERRUPT io_call: brasl %r14,do_IRQ tm __LC_MACHINE_FLAGS+6,0x10 # MACHINE_FLAG_LPAR jz io_return tpi 0 jz io_return mvc __PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID j io_loop io_return: LOCKDEP_SYS_EXIT TRACE_IRQS_ON io_tif: tm __TI_flags+7(%r12),_TIF_WORK jnz io_work # there is work to do (signals etc.) tm __LC_CPU_FLAGS+7,_CIF_WORK jnz io_work io_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 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 work # 2) if we return to kernel code and kvm is enabled check if we need to # modify the psw to leave SIE # 3) if we return to kernel code and preemptive scheduling is enabled check # the preemption counter and if it is zero call preempt_schedule_irq # Before any work can be done, a switch to the kernel stack is required. # io_work: tm __PT_PSW+1(%r11),0x01 # returning to user ? jo io_work_user # yes -> do resched & signal #ifdef CONFIG_PREEMPT # check for preemptive scheduling icm %r0,15,__TI_precount(%r12) jnz io_restore # preemption is disabled tm __TI_flags+7(%r12),_TIF_NEED_RESCHED jno io_restore # switch to kernel stack lg %r1,__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 io_return, call # TRACE_IRQS_OFF to keep things symmetrical TRACE_IRQS_OFF brasl %r14,preempt_schedule_irq j io_return #else j io_restore #endif # # Need to do work before returning to userspace, switch to kernel stack # io_work_user: lg %r1,__LC_KERNEL_STACK 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. # io_work_tif: tm __LC_CPU_FLAGS+7,_CIF_MCCK_PENDING jo io_mcck_pending tm __TI_flags+7(%r12),_TIF_NEED_RESCHED jo io_reschedule tm __TI_flags+7(%r12),_TIF_SIGPENDING jo io_sigpending tm __TI_flags+7(%r12),_TIF_NOTIFY_RESUME jo io_notify_resume tm __LC_CPU_FLAGS+7,_CIF_ASCE jo io_uaccess j io_return # beware of critical section cleanup # # _CIF_MCCK_PENDING is set, call handler # io_mcck_pending: # TRACE_IRQS_ON already done at io_return brasl %r14,s390_handle_mcck # TIF bit will be cleared by handler TRACE_IRQS_OFF j io_return # # _CIF_ASCE is set, load user space asce # io_uaccess: ni __LC_CPU_FLAGS+7,255-_CIF_ASCE lctlg %c1,%c1,__LC_USER_ASCE # load primary asce j io_return # # _TIF_NEED_RESCHED is set, call schedule # io_reschedule: # TRACE_IRQS_ON already done at io_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 io_return # # _TIF_SIGPENDING or is set, call do_signal # io_sigpending: # TRACE_IRQS_ON already done at io_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 io_return # # _TIF_NOTIFY_RESUME or is set, call do_notify_resume # io_notify_resume: # TRACE_IRQS_ON already done at io_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 io_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_THREAD_INFO larl %r13,system_call lmg %r8,%r9,__LC_EXT_OLD_PSW HANDLE_SIE_INTERCEPT %r14,3 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT tmhh %r8,0x0001 # interrupting from user ? jz ext_skip UPDATE_VTIME %r14,__LC_ASYNC_ENTER_TIMER LAST_BREAK %r14 ext_skip: 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) 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 io_return /* * Load idle PSW. The second "half" of this function is in cleanup_idle. */ ENTRY(psw_idle) stg %r3,__SF_EMPTY(%r15) larl %r1,psw_idle_lpsw+4 stg %r1,__SF_EMPTY+8(%r15) STCK __CLOCK_IDLE_ENTER(%r2) stpt __TIMER_IDLE_ENTER(%r2) psw_idle_lpsw: lpswe __SF_EMPTY(%r15) br %r14 psw_idle_end: __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_THREAD_INFO larl %r13,system_call lmg %r8,%r9,__LC_MCK_OLD_PSW HANDLE_SIE_INTERCEPT %r14,4 tm __LC_MCCK_CODE,0x80 # system damage? jo mcck_panic # yes -> rest of mcck code invalid lghi %r14,__LC_CPU_TIMER_SAVE_AREA mvc __LC_MCCK_ENTER_TIMER(8),0(%r14) tm __LC_MCCK_CODE+5,0x02 # stored cpu timer value 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: tm __LC_MCCK_CODE+2,0x09 # mwp + ia of old psw valid? jno mcck_panic # no -> skip cleanup critical SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_PANIC_STACK,PAGE_SHIFT tm %r8,0x0001 # interrupting from user ? jz mcck_skip UPDATE_VTIME %r14,__LC_MCCK_ENTER_TIMER LAST_BREAK %r14 mcck_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 mcck_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 tm __LC_CPU_FLAGS+7,_CIF_MCCK_PENDING jno mcck_return TRACE_IRQS_OFF brasl %r14,s390_handle_mcck TRACE_IRQS_ON mcck_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 mcck_panic: lg %r14,__LC_PANIC_STACK slgr %r14,%r15 srag %r14,%r14,PAGE_SHIFT jz 0f lg %r15,__LC_PANIC_STACK 0: aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) j mcck_skip # # PSW restart interrupt handler # ENTRY(restart_int_handler) 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 .align 8 cleanup_table: .quad system_call .quad sysc_do_svc .quad sysc_tif .quad sysc_restore .quad sysc_done .quad io_tif .quad io_restore .quad io_done .quad psw_idle .quad psw_idle_end cleanup_critical: clg %r9,BASED(cleanup_table) # system_call jl 0f clg %r9,BASED(cleanup_table+8) # sysc_do_svc jl cleanup_system_call clg %r9,BASED(cleanup_table+16) # sysc_tif jl 0f clg %r9,BASED(cleanup_table+24) # sysc_restore jl cleanup_sysc_tif clg %r9,BASED(cleanup_table+32) # sysc_done jl cleanup_sysc_restore clg %r9,BASED(cleanup_table+40) # io_tif jl 0f clg %r9,BASED(cleanup_table+48) # io_restore jl cleanup_io_tif clg %r9,BASED(cleanup_table+56) # io_done jl cleanup_io_restore clg %r9,BASED(cleanup_table+64) # psw_idle jl 0f clg %r9,BASED(cleanup_table+72) # psw_idle_end jl cleanup_idle 0: br %r14 cleanup_system_call: # check if stpt has been executed clg %r9,BASED(cleanup_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(cleanup_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(cleanup_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(cleanup_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(cleanup_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,sysc_do_svc br %r14 cleanup_system_call_insn: .quad system_call .quad sysc_stmg .quad sysc_per .quad sysc_vtime+18 .quad sysc_vtime+42 cleanup_sysc_tif: larl %r9,sysc_tif br %r14 cleanup_sysc_restore: clg %r9,BASED(cleanup_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 cleanup_sysc_restore_insn: .quad sysc_done - 4 cleanup_io_tif: larl %r9,io_tif br %r14 cleanup_io_restore: clg %r9,BASED(cleanup_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 cleanup_io_restore_insn: .quad io_done - 4 cleanup_idle: # 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(cleanup_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: # 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 cleanup_idle_insn: .quad psw_idle_lpsw /* * Integer constants */ .align 8 .Lcritical_start: .quad __critical_start .Lcritical_length: .quad __critical_end - __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(16,%r15),__SF_EMPTY+16(%r15) # host id & reason lmg %r0,%r13,0(%r3) # load guest gprs 0-13 lg %r14,__LC_GMAP # get gmap pointer ltgr %r14,%r14 jz sie_gmap lctlg %c1,%c1,__GMAP_ASCE(%r14) # load primary asce sie_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),1 # last exit... jnz sie_done LPP __SF_EMPTY(%r15) # set guest id sie 0(%r14) sie_done: LPP __SF_EMPTY+16(%r15) # set host id ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE lctlg %c1,%c1,__LC_USER_ASCE # load primary asce # 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 sie_done should not cause program # interrupts. So lets use a nop (47 00 00 00) as a landing pad. # See also HANDLE_SIE_INTERCEPT rewind_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+24(%r15) # return exit reason code br %r14 sie_fault: lghi %r14,-EFAULT stg %r14,__SF_EMPTY+24(%r15) # set exit reason code j sie_exit .align 8 .Lsie_critical: .quad sie_gmap .Lsie_critical_length: .quad sie_done - sie_gmap EX_TABLE(rewind_pad,sie_fault) EX_TABLE(sie_exit,sie_fault) #endif .section .rodata, "a" #define SYSCALL(esa,esame,emu) .long esame .globl sys_call_table sys_call_table: #include "syscalls.S" #undef SYSCALL #ifdef CONFIG_COMPAT #define SYSCALL(esa,esame,emu) .long emu .globl sys_call_table_emu sys_call_table_emu: #include "syscalls.S" #undef SYSCALL #endif