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s390: remove critical section cleanup from entry.S 

The current code is rather complex and caused a lot of subtle
and hard to debug bugs in the past. Simplify the code by calling
the system_call handler with interrupts disabled, save
machine state, and re-enable them later.

This requires significant changes to the machine check handling code
as well. When the machine check interrupt arrived while being in kernel
mode the new code will signal pending machine checks with a SIGP external
call. When userspace was interrupted, the handler will switch to the
kernel stack and directly execute s390_handle_mcck().

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This commit is contained in:
Sven Schnelle 2020-02-20 12:09:36 +01:00 committed by Vasily Gorbik
parent 11886c199d
commit 0b0ed657fe
9 changed files with 143 additions and 390 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/s390/include/asm/nmi.h
View File

@ -99,7 +99,7 @@ int nmi_alloc_per_cpu(struct lowcore *lc);
void nmi_free_per_cpu(struct lowcore *lc);
void s390_handle_mcck(void);
void s390_do_machine_check(struct pt_regs *regs);
int s390_do_machine_check(struct pt_regs *regs);
#endif /* __ASSEMBLY__ */
#endif /* _ASM_S390_NMI_H */

18
arch/s390/include/asm/processor.h
View File

@ -14,17 +14,15 @@
#include <linux/bits.h>
#define CIF_MCCK_PENDING 0 /* machine check handling is pending */
#define CIF_ASCE_PRIMARY 1 /* primary asce needs fixup / uaccess */
#define CIF_ASCE_SECONDARY 2 /* secondary asce needs fixup / uaccess */
#define CIF_NOHZ_DELAY 3 /* delay HZ disable for a tick */
#define CIF_FPU 4 /* restore FPU registers */
#define CIF_IGNORE_IRQ 5 /* ignore interrupt (for udelay) */
#define CIF_ENABLED_WAIT 6 /* in enabled wait state */
#define CIF_MCCK_GUEST 7 /* machine check happening in guest */
#define CIF_DEDICATED_CPU 8 /* this CPU is dedicated */
#define CIF_ASCE_PRIMARY 0 /* primary asce needs fixup / uaccess */
#define CIF_ASCE_SECONDARY 1 /* secondary asce needs fixup / uaccess */
#define CIF_NOHZ_DELAY 2 /* delay HZ disable for a tick */
#define CIF_FPU 3 /* restore FPU registers */
#define CIF_IGNORE_IRQ 4 /* ignore interrupt (for udelay) */
#define CIF_ENABLED_WAIT 5 /* in enabled wait state */
#define CIF_MCCK_GUEST 6 /* machine check happening in guest */
#define CIF_DEDICATED_CPU 7 /* this CPU is dedicated */
#define _CIF_MCCK_PENDING BIT(CIF_MCCK_PENDING)
#define _CIF_ASCE_PRIMARY BIT(CIF_ASCE_PRIMARY)
#define _CIF_ASCE_SECONDARY BIT(CIF_ASCE_SECONDARY)
#define _CIF_NOHZ_DELAY BIT(CIF_NOHZ_DELAY)

464
arch/s390/kernel/entry.S
View File

@ -55,14 +55,11 @@ _TIF_WORK = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
_TIF_UPROBE | _TIF_GUARDED_STORAGE | _TIF_PATCH_PENDING)
_TIF_TRACE = (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
_TIF_SYSCALL_TRACEPOINT)
_CIF_WORK = (_CIF_MCCK_PENDING | _CIF_ASCE_PRIMARY | \
_CIF_ASCE_SECONDARY | _CIF_FPU)
_CIF_WORK = (_CIF_ASCE_PRIMARY | _CIF_ASCE_SECONDARY | _CIF_FPU)
_PIF_WORK = (_PIF_PER_TRAP | _PIF_SYSCALL_RESTART)
_LPP_OFFSET = __LC_LPP
#define BASED(name) name-cleanup_critical(%r13)
.macro TRACE_IRQS_ON
#ifdef CONFIG_TRACE_IRQFLAGS
basr %r2,%r0
@ -116,17 +113,39 @@ _LPP_OFFSET = __LC_LPP
.macro SWITCH_ASYNC savearea,timer
tmhh %r8,0x0001 # interrupting from user ?
jnz 2f
#if IS_ENABLED(CONFIG_KVM)
lgr %r14,%r9
cghi %r14,__LC_RETURN_LPSWE
je 0f
slg %r14,BASED(.Lcritical_start)
clg %r14,BASED(.Lcritical_length)
jhe 1f
0:
larl %r13,.Lsie_gmap
slgr %r14,%r13
lghi %r13,.Lsie_done - .Lsie_gmap
clgr %r14,%r13
jhe 0f
lghi %r11,\savearea # inside critical section, do cleanup
brasl %r14,cleanup_critical
tmhh %r8,0x0001 # retest problem state after cleanup
jnz 2f
brasl %r14,.Lcleanup_sie
#endif
0: larl %r13,.Lpsw_idle_exit
cgr %r13,%r9
jne 1f
mvc __CLOCK_IDLE_EXIT(8,%r2), __LC_INT_CLOCK
mvc __TIMER_IDLE_EXIT(8,%r2), __LC_ASYNC_ENTER_TIMER
# account system time going idle
ni __LC_CPU_FLAGS+7,255-_CIF_ENABLED_WAIT
lg %r13,__LC_STEAL_TIMER
alg %r13,__CLOCK_IDLE_ENTER(%r2)
slg %r13,__LC_LAST_UPDATE_CLOCK
stg %r13,__LC_STEAL_TIMER
mvc __LC_LAST_UPDATE_CLOCK(8),__CLOCK_IDLE_EXIT(%r2)
lg %r13,__LC_SYSTEM_TIMER
alg %r13,__LC_LAST_UPDATE_TIMER
slg %r13,__TIMER_IDLE_ENTER(%r2)
stg %r13,__LC_SYSTEM_TIMER
mvc __LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2)
nihh %r8,0xfcfd # clear wait state and irq bits
1: lg %r14,__LC_ASYNC_STACK # are we already on the target stack?
slgr %r14,%r15
srag %r14,%r14,STACK_SHIFT
@ -152,12 +171,30 @@ _LPP_OFFSET = __LC_LPP
mvc __LC_LAST_UPDATE_TIMER(8),\enter_timer
.endm
.macro REENABLE_IRQS
.macro RESTORE_SM_CLEAR_PER
stg %r8,__LC_RETURN_PSW
ni __LC_RETURN_PSW,0xbf
ssm __LC_RETURN_PSW
.endm
.macro ENABLE_INTS
stosm __SF_EMPTY(%r15),3
.endm
.macro ENABLE_INTS_TRACE
TRACE_IRQS_ON
ENABLE_INTS
.endm
.macro DISABLE_INTS
stnsm __SF_EMPTY(%r15),0xfc
.endm
.macro DISABLE_INTS_TRACE
DISABLE_INTS
TRACE_IRQS_OFF
.endm
.macro STCK savearea
#ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
.insn s,0xb27c0000,\savearea # store clock fast
@ -254,8 +291,6 @@ ENTRY(__switch_to)
BR_EX %r14
ENDPROC(__switch_to)
.L__critical_start:
#if IS_ENABLED(CONFIG_KVM)
/*
* sie64a calling convention:
@ -288,7 +323,6 @@ ENTRY(sie64a)
BPEXIT __SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)
.Lsie_entry:
sie 0(%r14)
.Lsie_exit:
BPOFF
BPENTER __SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)
.Lsie_skip:
@ -341,7 +375,6 @@ EXPORT_SYMBOL(sie_exit)
ENTRY(system_call)
stpt __LC_SYNC_ENTER_TIMER
.Lsysc_stmg:
stmg %r8,%r15,__LC_SAVE_AREA_SYNC
BPOFF
lg %r12,__LC_CURRENT
@ -350,7 +383,6 @@ ENTRY(system_call)
.Lsysc_per:
lg %r15,__LC_KERNEL_STACK
la %r11,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs
.Lsysc_vtime:
UPDATE_VTIME %r8,%r9,__LC_SYNC_ENTER_TIMER
BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP
stmg %r0,%r7,__PT_R0(%r11)
@ -358,6 +390,7 @@ ENTRY(system_call)
mvc __PT_PSW(16,%r11),__LC_SVC_OLD_PSW
mvc __PT_INT_CODE(4,%r11),__LC_SVC_ILC
stg %r14,__PT_FLAGS(%r11)
ENABLE_INTS
.Lsysc_do_svc:
# clear user controlled register to prevent speculative use
xgr %r0,%r0
@ -393,26 +426,26 @@ ENTRY(system_call)
jnz .Lsysc_work
TSTMSK __TI_flags(%r12),_TIF_WORK
jnz .Lsysc_work # check for work
TSTMSK __LC_CPU_FLAGS,_CIF_WORK
TSTMSK __LC_CPU_FLAGS,(_CIF_WORK-_CIF_FPU)
jnz .Lsysc_work
BPEXIT __TI_flags(%r12),_TIF_ISOLATE_BP
.Lsysc_restore:
DISABLE_INTS
TSTMSK __LC_CPU_FLAGS, _CIF_FPU
jz .Lsysc_skip_fpu
brasl %r14,load_fpu_regs
.Lsysc_skip_fpu:
lg %r14,__LC_VDSO_PER_CPU
lmg %r0,%r10,__PT_R0(%r11)
mvc __LC_RETURN_PSW(16),__PT_PSW(%r11)
.Lsysc_exit_timer:
stpt __LC_EXIT_TIMER
mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
lmg %r11,%r15,__PT_R11(%r11)
b __LC_RETURN_LPSWE(%r0)
.Lsysc_done:
lmg %r0,%r15,__PT_R0(%r11)
b __LC_RETURN_LPSWE
#
# 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
TSTMSK __PT_FLAGS(%r11),_PIF_SYSCALL_RESTART
@ -436,11 +469,9 @@ ENTRY(system_call)
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_PRIMARY|_CIF_ASCE_SECONDARY)
jnz .Lsysc_asce
j .Lsysc_return # beware of critical section cleanup
j .Lsysc_return
#
# _TIF_NEED_RESCHED is set, call schedule
@ -449,13 +480,6 @@ ENTRY(system_call)
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_PRIMARY and/or _CIF_ASCE_SECONDARY set, load user space asce
#
@ -475,12 +499,6 @@ ENTRY(system_call)
larl %r14,.Lsysc_return
jg set_fs_fixup
#
# 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
@ -564,7 +582,6 @@ ENTRY(system_call)
jnh .Lsysc_tracenogo
sllg %r8,%r2,3
lg %r9,0(%r8,%r10)
.Lsysc_tracego:
lmg %r3,%r7,__PT_R3(%r11)
stg %r7,STACK_FRAME_OVERHEAD(%r15)
lg %r2,__PT_ORIG_GPR2(%r11)
@ -585,8 +602,6 @@ 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
@ -620,15 +635,16 @@ ENTRY(pgm_check_handler)
lghi %r10,1
0: lg %r12,__LC_CURRENT
lghi %r11,0
larl %r13,cleanup_critical
lmg %r8,%r9,__LC_PGM_OLD_PSW
tmhh %r8,0x0001 # test problem state bit
jnz 3f # -> fault in user space
#if IS_ENABLED(CONFIG_KVM)
# cleanup critical section for program checks in sie64a
lgr %r14,%r9
slg %r14,BASED(.Lsie_critical_start)
clg %r14,BASED(.Lsie_critical_length)
larl %r13,.Lsie_gmap
slgr %r14,%r13
lghi %r13,.Lsie_done - .Lsie_gmap
clgr %r14,%r13
jhe 1f
lg %r14,__SF_SIE_CONTROL(%r15) # get control block pointer
ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE
@ -680,7 +696,7 @@ ENTRY(pgm_check_handler)
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
6: REENABLE_IRQS
6: RESTORE_SM_CLEAR_PER
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
larl %r1,pgm_check_table
llgh %r10,__PT_INT_CODE+2(%r11)
@ -702,7 +718,7 @@ ENTRY(pgm_check_handler)
# PER event in supervisor state, must be kprobes
#
.Lpgm_kprobe:
REENABLE_IRQS
RESTORE_SM_CLEAR_PER
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
lgr %r2,%r11 # pass pointer to pt_regs
brasl %r14,do_per_trap
@ -713,11 +729,10 @@ ENTRY(pgm_check_handler)
#
.Lpgm_svcper:
mvc __LC_RETURN_PSW(8),__LC_SVC_NEW_PSW
lghi %r13,__TASK_thread
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
lpswe __LC_RETURN_PSW # branch to .Lsysc_per
ENDPROC(pgm_check_handler)
/*
@ -729,7 +744,6 @@ ENTRY(io_int_handler)
BPOFF
stmg %r8,%r15,__LC_SAVE_AREA_ASYNC
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)
@ -749,7 +763,12 @@ ENTRY(io_int_handler)
xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
TSTMSK __LC_CPU_FLAGS,_CIF_IGNORE_IRQ
jo .Lio_restore
#if IS_ENABLED(CONFIG_TRACE_IRQFLAGS)
tmhh %r8,0x300
jz 1f
TRACE_IRQS_OFF
1:
#endif
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
.Lio_loop:
lgr %r2,%r11 # pass pointer to pt_regs
@ -767,25 +786,27 @@ ENTRY(io_int_handler)
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:
#if IS_ENABLED(CONFIG_TRACE_IRQFLAGS)
tm __PT_PSW(%r11),3
jno 0f
TRACE_IRQS_ON
0:
#endif
lg %r14,__LC_VDSO_PER_CPU
lmg %r0,%r10,__PT_R0(%r11)
mvc __LC_RETURN_PSW(16),__PT_PSW(%r11)
tm __PT_PSW+1(%r11),0x01 # returning to user ?
jno .Lio_exit_kernel
BPEXIT __TI_flags(%r12),_TIF_ISOLATE_BP
.Lio_exit_timer:
stpt __LC_EXIT_TIMER
mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
.Lio_exit_kernel:
lmg %r11,%r15,__PT_R11(%r11)
b __LC_RETURN_LPSWE(%r0)
lmg %r0,%r15,__PT_R0(%r11)
b __LC_RETURN_LPSWE
.Lio_done:
#
@ -813,9 +834,6 @@ ENTRY(io_int_handler)
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
@ -835,9 +853,6 @@ ENTRY(io_int_handler)
#
# 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
#ifdef CONFIG_LIVEPATCH
@ -854,15 +869,6 @@ ENTRY(io_int_handler)
jo .Lio_vxrs
TSTMSK __LC_CPU_FLAGS,(_CIF_ASCE_PRIMARY|_CIF_ASCE_SECONDARY)
jnz .Lio_asce
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
#
@ -895,23 +901,19 @@ ENTRY(io_int_handler)
# _TIF_GUARDED_STORAGE is set, call guarded_storage_load
#
.Lio_guarded_storage:
# TRACE_IRQS_ON already done at .Lio_return
ssm __LC_SVC_NEW_PSW # reenable interrupts
ENABLE_INTS_TRACE
lgr %r2,%r11 # pass pointer to pt_regs
brasl %r14,gs_load_bc_cb
ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
TRACE_IRQS_OFF
DISABLE_INTS_TRACE
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
ENABLE_INTS_TRACE
brasl %r14,schedule # call scheduler
ssm __LC_PGM_NEW_PSW # disable I/O and ext. interrupts
TRACE_IRQS_OFF
DISABLE_INTS_TRACE
j .Lio_return
#
@ -928,24 +930,20 @@ ENTRY(io_int_handler)
# _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
ENABLE_INTS_TRACE
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
DISABLE_INTS_TRACE
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
ENABLE_INTS_TRACE
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
DISABLE_INTS_TRACE
j .Lio_return
ENDPROC(io_int_handler)
@ -958,7 +956,6 @@ ENTRY(ext_int_handler)
BPOFF
stmg %r8,%r15,__LC_SAVE_AREA_ASYNC
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)
@ -981,7 +978,12 @@ ENTRY(ext_int_handler)
xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
TSTMSK __LC_CPU_FLAGS,_CIF_IGNORE_IRQ
jo .Lio_restore
#if IS_ENABLED(CONFIG_TRACE_IRQFLAGS)
tmhh %r8,0x300
jz 1f
TRACE_IRQS_OFF
1:
#endif
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
lgr %r2,%r11 # pass pointer to pt_regs
lghi %r3,EXT_INTERRUPT
@ -990,11 +992,11 @@ ENTRY(ext_int_handler)
ENDPROC(ext_int_handler)
/*
* Load idle PSW. The second "half" of this function is in .Lcleanup_idle.
* Load idle PSW.
*/
ENTRY(psw_idle)
stg %r3,__SF_EMPTY(%r15)
larl %r1,.Lpsw_idle_lpsw+4
larl %r1,.Lpsw_idle_exit
stg %r1,__SF_EMPTY+8(%r15)
larl %r1,smp_cpu_mtid
llgf %r1,0(%r1)
@ -1006,10 +1008,9 @@ ENTRY(psw_idle)
BPON
STCK __CLOCK_IDLE_ENTER(%r2)
stpt __TIMER_IDLE_ENTER(%r2)
.Lpsw_idle_lpsw:
lpswe __SF_EMPTY(%r15)
.Lpsw_idle_exit:
BR_EX %r14
.Lpsw_idle_end:
ENDPROC(psw_idle)
/*
@ -1020,6 +1021,7 @@ ENDPROC(psw_idle)
* of the register contents at return from io or a system call.
*/
ENTRY(save_fpu_regs)
stnsm __SF_EMPTY(%r15),0xfc
lg %r2,__LC_CURRENT
aghi %r2,__TASK_thread
TSTMSK __LC_CPU_FLAGS,_CIF_FPU
@ -1051,6 +1053,7 @@ ENTRY(save_fpu_regs)
.Lsave_fpu_regs_done:
oi __LC_CPU_FLAGS+7,_CIF_FPU
.Lsave_fpu_regs_exit:
ssm __SF_EMPTY(%r15)
BR_EX %r14
.Lsave_fpu_regs_end:
ENDPROC(save_fpu_regs)
@ -1102,8 +1105,6 @@ load_fpu_regs:
.Lload_fpu_regs_end:
ENDPROC(load_fpu_regs)
.L__critical_end:
/*
* Machine check handler routines
*/
@ -1116,7 +1117,6 @@ ENTRY(mcck_int_handler)
lam %a0,%a15,__LC_AREGS_SAVE_AREA-4095(%r1) # validate acrs
lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# validate gprs
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
@ -1202,15 +1202,13 @@ ENTRY(mcck_int_handler)
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
cghi %r2,0
je .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
TSTMSK __LC_CPU_FLAGS,_CIF_MCCK_PENDING
jno .Lmcck_return
TRACE_IRQS_OFF
brasl %r14,s390_handle_mcck
TRACE_IRQS_ON
@ -1280,265 +1278,23 @@ ENTRY(stack_overflow)
ENDPROC(stack_overflow)
#endif
ENTRY(cleanup_critical)
cghi %r9,__LC_RETURN_LPSWE
je .Lcleanup_lpswe
#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_EX %r14,%r11
ENDPROC(cleanup_critical)
.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:
cghi %r11,__LC_SAVE_AREA_ASYNC #Is this in normal interrupt?
je 1f
slg %r9,BASED(.Lsie_crit_mcck_start)
clg %r9,BASED(.Lsie_crit_mcck_length)
jh 1f
oi __LC_CPU_FLAGS+7, _CIF_MCCK_GUEST
1: BPENTER __SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)
cghi %r11,__LC_SAVE_AREA_ASYNC #Is this in normal interrupt?
je 1f
larl %r13,.Lsie_entry
slgr %r9,%r13
larl %r13,.Lsie_skip
clgr %r9,%r13
jh 1f
oi __LC_CPU_FLAGS+7, _CIF_MCCK_GUEST
1: BPENTER __SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)
lg %r9,__SF_SIE_CONTROL(%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_EX %r14,%r11
#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 register r12 task struct pointer
stg %r12,32(%r11)
# set up saved register r13 __TASK_thread offset
mvc 40(8,%r11),BASED(.Lcleanup_system_call_const)
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
BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP
# 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_EX %r14,%r11
.Lcleanup_system_call_insn:
.quad system_call
.quad .Lsysc_stmg
.quad .Lsysc_per
.quad .Lsysc_vtime+36
.quad .Lsysc_vtime+42
.Lcleanup_system_call_const:
.quad __TASK_thread
.Lcleanup_sysc_tif:
larl %r9,.Lsysc_tif
BR_EX %r14,%r11
.Lcleanup_sysc_restore:
# check if stpt has been executed
clg %r9,BASED(.Lcleanup_sysc_restore_insn)
jh 0f
mvc __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER
cghi %r11,__LC_SAVE_AREA_ASYNC
je 0f
mvc __LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER
0: clg %r9,BASED(.Lcleanup_sysc_restore_insn+8)
je 1f
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)
.Lcleanup_lpswe:
1: lmg %r8,%r9,__LC_RETURN_PSW
BR_EX %r14,%r11
.Lcleanup_sysc_restore_insn:
.quad .Lsysc_exit_timer
.quad .Lsysc_done - 4
.Lcleanup_io_tif:
larl %r9,.Lio_tif
BR_EX %r14,%r11
.Lcleanup_io_restore:
# check if stpt has been executed
clg %r9,BASED(.Lcleanup_io_restore_insn)
jh 0f
mvc __LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER
0: clg %r9,BASED(.Lcleanup_io_restore_insn+8)
je 1f
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)
1: lmg %r8,%r9,__LC_RETURN_PSW
BR_EX %r14,%r11
.Lcleanup_io_restore_insn:
.quad .Lio_exit_timer
.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
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
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_EX %r14,%r11
.Lcleanup_idle_insn:
.quad .Lpsw_idle_lpsw
.Lcleanup_save_fpu_regs:
larl %r9,save_fpu_regs
BR_EX %r14,%r11
.Lcleanup_load_fpu_regs:
larl %r9,load_fpu_regs
BR_EX %r14,%r11
/*
* 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
.Lsie_crit_mcck_start:
.quad .Lsie_entry
.Lsie_crit_mcck_length:
.quad .Lsie_skip - .Lsie_entry
#endif
.section .rodata, "a"
#define SYSCALL(esame,emu) .quad __s390x_ ## esame

14
arch/s390/kernel/idle.c
View File

@ -24,19 +24,19 @@ void enabled_wait(void)
{
struct s390_idle_data *idle = this_cpu_ptr(&s390_idle);
unsigned long long idle_time;
unsigned long psw_mask;
unsigned long psw_mask, flags;
trace_hardirqs_on();
/* Wait for external, I/O or machine check interrupt. */
psw_mask = PSW_KERNEL_BITS | PSW_MASK_WAIT | PSW_MASK_DAT |
PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
clear_cpu_flag(CIF_NOHZ_DELAY);
local_irq_save(flags);
/* Call the assembler magic in entry.S */
psw_idle(idle, psw_mask);
local_irq_restore(flags);
trace_hardirqs_off();
/* Account time spent with enabled wait psw loaded as idle time. */
write_seqcount_begin(&idle->seqcount);
@ -118,22 +118,16 @@ u64 arch_cpu_idle_time(int cpu)
void arch_cpu_idle_enter(void)
{
local_mcck_disable();
}
void arch_cpu_idle(void)
{
if (!test_cpu_flag(CIF_MCCK_PENDING))
/* Halt the cpu and keep track of cpu time accounting. */
enabled_wait();
enabled_wait();
local_irq_enable();
}
void arch_cpu_idle_exit(void)
{
local_mcck_enable();
if (test_cpu_flag(CIF_MCCK_PENDING))
s390_handle_mcck();
}
void arch_cpu_idle_dead(void)

23
arch/s390/kernel/nmi.c
View File

@ -148,7 +148,6 @@ void s390_handle_mcck(void)
local_mcck_disable();
mcck = *this_cpu_ptr(&cpu_mcck);
memset(this_cpu_ptr(&cpu_mcck), 0, sizeof(mcck));
clear_cpu_flag(CIF_MCCK_PENDING);
local_mcck_enable();
local_irq_restore(flags);
@ -333,7 +332,7 @@ NOKPROBE_SYMBOL(s390_backup_mcck_info);
/*
* machine check handler.
*/
void notrace s390_do_machine_check(struct pt_regs *regs)
int notrace s390_do_machine_check(struct pt_regs *regs)
{
static int ipd_count;
static DEFINE_SPINLOCK(ipd_lock);
@ -342,6 +341,7 @@ void notrace s390_do_machine_check(struct pt_regs *regs)
unsigned long long tmp;
union mci mci;
unsigned long mcck_dam_code;
int mcck_pending = 0;
nmi_enter();
inc_irq_stat(NMI_NMI);
@ -400,7 +400,7 @@ void notrace s390_do_machine_check(struct pt_regs *regs)
*/
mcck->kill_task = 1;
mcck->mcck_code = mci.val;
set_cpu_flag(CIF_MCCK_PENDING);
mcck_pending = 1;
}
/*
@ -420,8 +420,7 @@ void notrace s390_do_machine_check(struct pt_regs *regs)
mcck->stp_queue |= stp_sync_check();
if (S390_lowcore.external_damage_code & (1U << ED_STP_ISLAND))
mcck->stp_queue |= stp_island_check();
if (mcck->stp_queue)
set_cpu_flag(CIF_MCCK_PENDING);
mcck_pending = 1;
}
/*
@ -442,12 +441,12 @@ void notrace s390_do_machine_check(struct pt_regs *regs)
if (mci.cp) {
/* Channel report word pending */
mcck->channel_report = 1;
set_cpu_flag(CIF_MCCK_PENDING);
mcck_pending = 1;
}
if (mci.w) {
/* Warning pending */
mcck->warning = 1;
set_cpu_flag(CIF_MCCK_PENDING);
mcck_pending = 1;
}
/*
@ -462,7 +461,17 @@ void notrace s390_do_machine_check(struct pt_regs *regs)
*((long *)(regs->gprs[15] + __SF_SIE_REASON)) = -EINTR;
}
clear_cpu_flag(CIF_MCCK_GUEST);
if (user_mode(regs) && mcck_pending) {
nmi_exit();
return 1;
}
if (mcck_pending)
schedule_mcck_handler();
nmi_exit();
return 0;
}
NOKPROBE_SYMBOL(s390_do_machine_check);

3
arch/s390/kernel/setup.c
View File

@ -384,8 +384,7 @@ static void __init setup_lowcore_dat_off(void)
lc->restart_psw.addr = (unsigned long) restart_int_handler;
lc->external_new_psw.mask = PSW_KERNEL_BITS | PSW_MASK_MCHECK;
lc->external_new_psw.addr = (unsigned long) ext_int_handler;
lc->svc_new_psw.mask = PSW_KERNEL_BITS |
PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
lc->svc_new_psw.mask = PSW_KERNEL_BITS | PSW_MASK_MCHECK;
lc->svc_new_psw.addr = (unsigned long) system_call;
lc->program_new_psw.mask = PSW_KERNEL_BITS | PSW_MASK_MCHECK;
lc->program_new_psw.addr = (unsigned long) pgm_check_handler;

3
arch/s390/kvm/kvm-s390.c
View File

@ -3995,9 +3995,6 @@ static int vcpu_pre_run(struct kvm_vcpu *vcpu)
if (need_resched())
schedule();
if (test_cpu_flag(CIF_MCCK_PENDING))
s390_handle_mcck();
if (!kvm_is_ucontrol(vcpu->kvm)) {
rc = kvm_s390_deliver_pending_interrupts(vcpu);
if (rc)

2
arch/s390/kvm/vsie.c
View File

@ -1002,8 +1002,6 @@ static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
if (need_resched())
schedule();
if (test_cpu_flag(CIF_MCCK_PENDING))
s390_handle_mcck();
srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);

4
arch/s390/lib/delay.c
View File

@ -33,7 +33,7 @@ EXPORT_SYMBOL(__delay);
static void __udelay_disabled(unsigned long long usecs)
{
unsigned long cr0, cr0_new, psw_mask;
unsigned long cr0, cr0_new, psw_mask, flags;
struct s390_idle_data idle;
u64 end;
@ -45,7 +45,9 @@ static void __udelay_disabled(unsigned long long usecs)
psw_mask = __extract_psw() | PSW_MASK_EXT | PSW_MASK_WAIT;
set_clock_comparator(end);
set_cpu_flag(CIF_IGNORE_IRQ);
local_irq_save(flags);
psw_idle(&idle, psw_mask);
local_irq_restore(flags);
clear_cpu_flag(CIF_IGNORE_IRQ);
set_clock_comparator(S390_lowcore.clock_comparator);
__ctl_load(cr0, 0, 0);