diff options
Diffstat (limited to 'arch/s390/kernel/entry.S')
| -rw-r--r-- | arch/s390/kernel/entry.S | 1059 |
1 files changed, 1059 insertions, 0 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S new file mode 100644 index 000000000000..c329446a951d --- /dev/null +++ b/arch/s390/kernel/entry.S @@ -0,0 +1,1059 @@ +/* + * 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 .Lrewind_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 + +.L__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 +.Lsysc_stmg: + stmg %r8,%r15,__LC_SAVE_AREA_SYNC + lg %r10,__LC_LAST_BREAK + lg %r12,__LC_THREAD_INFO + lghi %r14,_PIF_SYSCALL +.Lsysc_per: + lg %r15,__LC_KERNEL_STACK + la %r11,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs +.Lsysc_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) +.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. + tm __TI_flags+7(%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: + tm __PT_PSW+1(%r11),0x01 # returning to user ? + jno .Lsysc_restore + tm __PT_FLAGS+7(%r11),_PIF_WORK + jnz .Lsysc_work + tm __TI_flags+7(%r12),_TIF_WORK + jnz .Lsysc_work # check for work + tm __LC_CPU_FLAGS+7,_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: + tm __LC_CPU_FLAGS+7,_CIF_MCCK_PENDING + jo .Lsysc_mcck_pending + tm __TI_flags+7(%r12),_TIF_NEED_RESCHED + jo .Lsysc_reschedule +#ifdef CONFIG_UPROBES + tm __TI_flags+7(%r12),_TIF_UPROBE + jo .Lsysc_uprobe_notify +#endif + tm __PT_FLAGS+7(%r11),_PIF_PER_TRAP + jo .Lsysc_singlestep + tm __TI_flags+7(%r12),_TIF_SIGPENDING + jo .Lsysc_sigpending + tm __TI_flags+7(%r12),_TIF_NOTIFY_RESUME + jo .Lsysc_notify_resume + tm __LC_CPU_FLAGS+7,_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 + +# +# _TIF_SIGPENDING is set, call do_signal +# +.Lsysc_sigpending: + lgr %r2,%r11 # pass pointer to pt_regs + brasl %r14,do_signal + tm __PT_FLAGS+7(%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: + tm __TI_flags+7(%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_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 .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_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 .Lpgm_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 .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 +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 .Lsysc_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 .Lsysc_return + +# +# 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 .Lsysc_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_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 .Lio_skip + UPDATE_VTIME %r14,__LC_ASYNC_ENTER_TIMER + LAST_BREAK %r14 +.Lio_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) +.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 + tm __LC_MACHINE_FLAGS+6,0x10 # 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: + tm __TI_flags+7(%r12),_TIF_WORK + jnz .Lio_work # there is work to do (signals etc.) + tm __LC_CPU_FLAGS+7,_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,__TI_precount(%r12) + jnz .Lio_restore # preemption is disabled + tm __TI_flags+7(%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: + tm __LC_CPU_FLAGS+7,_CIF_MCCK_PENDING + jo .Lio_mcck_pending + tm __TI_flags+7(%r12),_TIF_NEED_RESCHED + jo .Lio_reschedule + tm __TI_flags+7(%r12),_TIF_SIGPENDING + jo .Lio_sigpending + tm __TI_flags+7(%r12),_TIF_NOTIFY_RESUME + jo .Lio_notify_resume + tm __LC_CPU_FLAGS+7,_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 + +# +# _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_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 .Lext_skip + UPDATE_VTIME %r14,__LC_ASYNC_ENTER_TIMER + LAST_BREAK %r14 +.Lext_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 .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) + STCK __CLOCK_IDLE_ENTER(%r2) + stpt __TIMER_IDLE_ENTER(%r2) +.Lpsw_idle_lpsw: + lpswe __SF_EMPTY(%r15) + br %r14 +.Lpsw_idle_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_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 .Lmcck_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 .Lmcck_panic # no -> skip cleanup critical + SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_PANIC_STACK,PAGE_SHIFT + tm %r8,0x0001 # interrupting from user ? + jz .Lmcck_skip + UPDATE_VTIME %r14,__LC_MCCK_ENTER_TIMER + LAST_BREAK %r14 +.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 + tm __LC_CPU_FLAGS+7,_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 %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 .Lmcck_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 +.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 + +cleanup_critical: + 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 +0: br %r14 + + +.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+18 + .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: + # 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: # 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 + +/* + * Integer constants + */ + .align 8 +.Lcritical_start: + .quad .L__critical_start +.Lcritical_length: + .quad .L__critical_end - .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(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 .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),1 # last exit... + jnz .Lsie_done + LPP __SF_EMPTY(%r15) # set guest id + sie 0(%r14) +.Lsie_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 .Lsie_done should not cause program +# interrupts. So lets use a nop (47 00 00 00) as a landing pad. +# See also HANDLE_SIE_INTERCEPT +.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+24(%r15) # return exit reason code + br %r14 +.Lsie_fault: + lghi %r14,-EFAULT + stg %r14,__SF_EMPTY+24(%r15) # set exit reason code + j sie_exit + + .align 8 +.Lsie_critical: + .quad .Lsie_gmap +.Lsie_critical_length: + .quad .Lsie_done - .Lsie_gmap + + EX_TABLE(.Lrewind_pad,.Lsie_fault) + EX_TABLE(sie_exit,.Lsie_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 |