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author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-04-15 10:55:07 (GMT) |
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committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-05-20 06:58:47 (GMT) |
commit | d3a73acbc26a4a81a01a35fd162973e53d0386f5 (patch) | |
tree | 5b8fd3880f3b38575b1a043f3f4f07623a633bd1 /arch/s390/kernel/entry64.S | |
parent | beef560b4cdfafb2211a856e1d722540f5151933 (diff) | |
download | linux-d3a73acbc26a4a81a01a35fd162973e53d0386f5.tar.xz |
s390: split TIF bits into CIF, PIF and TIF bits
The oi and ni instructions used in entry[64].S to set and clear bits
in the thread-flags are not guaranteed to be atomic in regard to other
CPUs. Split the TIF bits into CPU, pt_regs and thread-info specific
bits. Updates on the TIF bits are done with atomic instructions,
updates on CPU and pt_regs bits are done with non-atomic instructions.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/entry64.S')
-rw-r--r-- | arch/s390/kernel/entry64.S | 82 |
1 files changed, 42 insertions, 40 deletions
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S index d15e7bf..c41f3f9 100644 --- a/arch/s390/kernel/entry64.S +++ b/arch/s390/kernel/entry64.S @@ -42,13 +42,11 @@ STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER STACK_SIZE = 1 << STACK_SHIFT STACK_INIT = STACK_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE -_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \ - _TIF_MCCK_PENDING | _TIF_PER_TRAP | _TIF_ASCE) -_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \ - _TIF_MCCK_PENDING | _TIF_ASCE) -_TIF_TRACE = (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \ - _TIF_SYSCALL_TRACEPOINT) -_TIF_TRANSFER = (_TIF_MCCK_PENDING | _TIF_ASCE) +_TIF_WORK = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED) +_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) @@ -190,13 +188,7 @@ ENTRY(__switch_to) 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 - llill %r6,_TIF_TRANSFER # transfer TIF bits - ng %r6,__TI_flags(%r4) # isolate TIF bits - jz 0f - og %r6,__TI_flags(%r5) # set TIF bits of next - stg %r6,__TI_flags(%r5) - ni __TI_flags+7(%r4),255-_TIF_TRANSFER # clear TIF bits of prev -0: lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task + lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task br %r14 __critical_start: @@ -211,6 +203,7 @@ 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 @@ -221,8 +214,8 @@ sysc_vtime: 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: - oi __TI_flags+7(%r12),_TIF_SYSCALL 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 @@ -238,7 +231,7 @@ sysc_nr_ok: stg %r2,__PT_ORIG_GPR2(%r11) stg %r7,STACK_FRAME_OVERHEAD(%r15) lgf %r9,0(%r8,%r10) # get system call add. - tm __TI_flags+6(%r12),_TIF_TRACE >> 8 + tm __TI_flags+7(%r12),_TIF_TRACE jnz sysc_tracesys basr %r14,%r9 # call sys_xxxx stg %r2,__PT_R2(%r11) # store return value @@ -248,9 +241,12 @@ sysc_return: sysc_tif: tm __PT_PSW+1(%r11),0x01 # returning to user ? jno sysc_restore - tm __TI_flags+7(%r12),_TIF_WORK_SVC + tm __PT_FLAGS+7(%r11),_PIF_WORK + jnz sysc_work + tm __TI_flags+7(%r12),_TIF_WORK jnz sysc_work # check for work - ni __TI_flags+7(%r12),255-_TIF_SYSCALL + tm __LC_CPU_FLAGS+7,_CIF_WORK + jnz sysc_work sysc_restore: lg %r14,__LC_VDSO_PER_CPU lmg %r0,%r10,__PT_R0(%r11) @@ -265,17 +261,17 @@ sysc_done: # One of the work bits is on. Find out which one. # sysc_work: - tm __TI_flags+7(%r12),_TIF_MCCK_PENDING + tm __LC_CPU_FLAGS+7,_CIF_MCCK_PENDING jo sysc_mcck_pending tm __TI_flags+7(%r12),_TIF_NEED_RESCHED jo sysc_reschedule - tm __TI_flags+7(%r12),_TIF_PER_TRAP + 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 __TI_flags+7(%r12),_TIF_ASCE + tm __LC_CPU_FLAGS+7,_CIF_ASCE jo sysc_uaccess j sysc_return # beware of critical section cleanup @@ -287,17 +283,17 @@ sysc_reschedule: jg schedule # -# _TIF_MCCK_PENDING is set, call handler +# _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 # -# _TIF_ASCE is set, load user space asce +# _CIF_ASCE is set, load user space asce # sysc_uaccess: - ni __TI_flags+7(%r12),255-_TIF_ASCE + ni __LC_CPU_FLAGS+7,255-_CIF_ASCE lctlg %c1,%c1,__LC_USER_ASCE # load primary asce j sysc_return @@ -307,7 +303,7 @@ sysc_uaccess: sysc_sigpending: lgr %r2,%r11 # pass pointer to pt_regs brasl %r14,do_signal - tm __TI_flags+7(%r12),_TIF_SYSCALL + 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 @@ -327,10 +323,10 @@ sysc_notify_resume: jg do_notify_resume # -# _TIF_PER_TRAP is set, call do_per_trap +# _PIF_PER_TRAP is set, call do_per_trap # sysc_singlestep: - ni __TI_flags+7(%r12),255-_TIF_PER_TRAP + 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 @@ -357,7 +353,7 @@ sysc_tracego: basr %r14,%r9 # call sys_xxx stg %r2,__PT_R2(%r11) # store return value sysc_tracenogo: - tm __TI_flags+6(%r12),_TIF_TRACE >> 8 + tm __TI_flags+7(%r12),_TIF_TRACE jz sysc_return lgr %r2,%r11 # pass pointer to pt_regs larl %r14,sysc_return @@ -416,12 +412,13 @@ ENTRY(pgm_check_handler) 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 __TI_flags+7(%r12),_TIF_PER_TRAP + 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_CAUSE mvc __THREAD_per_paid(1,%r14),__LC_PER_PAID @@ -451,10 +448,10 @@ pgm_kprobe: # single stepped system call # pgm_svcper: - oi __TI_flags+7(%r12),_TIF_PER_TRAP 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 /* @@ -479,6 +476,7 @@ io_skip: 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: @@ -499,8 +497,10 @@ io_return: LOCKDEP_SYS_EXIT TRACE_IRQS_ON io_tif: - tm __TI_flags+7(%r12),_TIF_WORK_INT + 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) @@ -513,7 +513,7 @@ io_done: # # There is work todo, find out in which context we have been interrupted: -# 1) if we return to user space we can do all _TIF_WORK_INT work +# 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 @@ -557,11 +557,9 @@ io_work_user: # # One of the work bits is on. Find out which one. -# Checked are: _TIF_SIGPENDING, _TIF_NOTIFY_RESUME, _TIF_NEED_RESCHED -# and _TIF_MCCK_PENDING # io_work_tif: - tm __TI_flags+7(%r12),_TIF_MCCK_PENDING + tm __LC_CPU_FLAGS+7,_CIF_MCCK_PENDING jo io_mcck_pending tm __TI_flags+7(%r12),_TIF_NEED_RESCHED jo io_reschedule @@ -569,12 +567,12 @@ io_work_tif: jo io_sigpending tm __TI_flags+7(%r12),_TIF_NOTIFY_RESUME jo io_notify_resume - tm __TI_flags+7(%r12),_TIF_ASCE + tm __LC_CPU_FLAGS+7,_CIF_ASCE jo io_uaccess j io_return # beware of critical section cleanup # -# _TIF_MCCK_PENDING is set, call handler +# _CIF_MCCK_PENDING is set, call handler # io_mcck_pending: # TRACE_IRQS_ON already done at io_return @@ -583,10 +581,10 @@ io_mcck_pending: j io_return # -# _TIF_ASCE is set, load user space asce +# _CIF_ASCE is set, load user space asce # io_uaccess: - ni __TI_flags+7(%r12),255-_TIF_ASCE + ni __LC_CPU_FLAGS+7,255-_CIF_ASCE lctlg %c1,%c1,__LC_USER_ASCE # load primary asce j io_return @@ -650,6 +648,7 @@ ext_skip: 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 @@ -716,6 +715,7 @@ mcck_skip: 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 @@ -727,7 +727,7 @@ mcck_skip: la %r11,STACK_FRAME_OVERHEAD(%r1) lgr %r15,%r1 ssm __LC_PGM_NEW_PSW # turn dat on, keep irqs off - tm __TI_flags+7(%r12),_TIF_MCCK_PENDING + tm __LC_CPU_FLAGS+7,_CIF_MCCK_PENDING jno mcck_return TRACE_IRQS_OFF brasl %r14,s390_handle_mcck @@ -884,6 +884,8 @@ cleanup_system_call: 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 |