cf87b7439e
When the kernel is IPLed without the CLEAR option and switches to 64-bit, the high-order half of the registers might contain random values. This can cause addressing exceptions and the kernel enters an interrupt loop. Initialize the high-order half of the general purpose registers with zeros after switching to 64-bit mode. Cc: <stable@kernel.org> Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
178 lines
4.9 KiB
ArmAsm
178 lines
4.9 KiB
ArmAsm
/*
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* arch/s390/kernel/head64.S
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*
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* Copyright (C) IBM Corp. 1999,2006
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*
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* Author(s): Hartmut Penner <hp@de.ibm.com>
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* Martin Schwidefsky <schwidefsky@de.ibm.com>
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* Rob van der Heij <rvdhei@iae.nl>
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* Heiko Carstens <heiko.carstens@de.ibm.com>
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*
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*/
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.org 0x11000
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startup_continue:
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basr %r13,0 # get base
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.LPG1: sll %r13,1 # remove high order bit
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srl %r13,1
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#ifdef CONFIG_ZFCPDUMP
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# check if we have been ipled using zfcp dump:
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tm 0xb9,0x01 # test if subchannel is enabled
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jno .nodump # subchannel disabled
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l %r1,0xb8
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la %r5,.Lipl_schib-.LPG1(%r13)
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stsch 0(%r5) # get schib of subchannel
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jne .nodump # schib not available
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tm 5(%r5),0x01 # devno valid?
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jno .nodump
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tm 4(%r5),0x80 # qdio capable device?
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jno .nodump
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l %r2,20(%r0) # address of ipl parameter block
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lhi %r3,0
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ic %r3,0x148(%r2) # get opt field
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chi %r3,0x20 # load with dump?
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jne .nodump
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# store all prefix registers in case of load with dump:
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la %r7,0 # base register for 0 page
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la %r8,0 # first cpu
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l %r11,.Lpref_arr_ptr-.LPG1(%r13) # address of prefix array
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ahi %r11,4 # skip boot cpu
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lr %r12,%r11
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ahi %r12,(CONFIG_NR_CPUS*4) # end of prefix array
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stap .Lcurrent_cpu+2-.LPG1(%r13) # store current cpu addr
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1:
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cl %r8,.Lcurrent_cpu-.LPG1(%r13) # is ipl cpu ?
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je 4f # if yes get next cpu
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2:
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lr %r9,%r7
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sigp %r9,%r8,0x9 # stop & store status of cpu
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brc 8,3f # accepted
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brc 4,4f # status stored: next cpu
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brc 2,2b # busy: try again
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brc 1,4f # not op: next cpu
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3:
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mvc 0(4,%r11),264(%r7) # copy prefix register to prefix array
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ahi %r11,4 # next element in prefix array
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clr %r11,%r12
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je 5f # no more space in prefix array
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4:
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ahi %r8,1 # next cpu (r8 += 1)
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chi %r8,MAX_CPU_ADDRESS # is last possible cpu ?
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jle 1b # jump if not last cpu
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5:
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lhi %r1,2 # mode 2 = esame (dump)
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j 6f
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.align 4
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.Lipl_schib:
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.rept 13
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.long 0
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.endr
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.nodump:
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lhi %r1,1 # mode 1 = esame (normal ipl)
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6:
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#else
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lhi %r1,1 # mode 1 = esame (normal ipl)
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#endif /* CONFIG_ZFCPDUMP */
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mvi __LC_AR_MODE_ID,1 # set esame flag
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slr %r0,%r0 # set cpuid to zero
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sigp %r1,%r0,0x12 # switch to esame mode
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sam64 # switch to 64 bit mode
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llgfr %r13,%r13 # clear high-order half of base reg
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lmh %r0,%r15,.Lzero64-.LPG1(%r13) # clear high-order half
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lctlg %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
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lg %r12,.Lparmaddr-.LPG1(%r13) # pointer to parameter area
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# move IPL device to lowcore
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lghi %r0,__LC_PASTE
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stg %r0,__LC_VDSO_PER_CPU
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#
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# Setup stack
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#
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larl %r15,init_thread_union
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stg %r15,__LC_THREAD_INFO # cache thread info in lowcore
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lg %r14,__TI_task(%r15) # cache current in lowcore
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stg %r14,__LC_CURRENT
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aghi %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union + THREAD_SIZE
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stg %r15,__LC_KERNEL_STACK # set end of kernel stack
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aghi %r15,-160
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#
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# Save ipl parameters, clear bss memory, initialize storage key for kernel pages,
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# and create a kernel NSS if the SAVESYS= parm is defined
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#
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brasl %r14,startup_init
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lpswe .Lentry-.LPG1(13) # jump to _stext in primary-space,
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# virtual and never return ...
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.align 16
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.Lentry:.quad 0x0000000180000000,_stext
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.Lctl: .quad 0x04350002 # cr0: various things
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.quad 0 # cr1: primary space segment table
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.quad .Lduct # cr2: dispatchable unit control table
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.quad 0 # cr3: instruction authorization
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.quad 0 # cr4: instruction authorization
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.quad .Lduct # cr5: primary-aste origin
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.quad 0 # cr6: I/O interrupts
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.quad 0 # cr7: secondary space segment table
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.quad 0 # cr8: access registers translation
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.quad 0 # cr9: tracing off
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.quad 0 # cr10: tracing off
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.quad 0 # cr11: tracing off
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.quad 0 # cr12: tracing off
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.quad 0 # cr13: home space segment table
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.quad 0xc0000000 # cr14: machine check handling off
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.quad 0 # cr15: linkage stack operations
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.Lpcmsk:.quad 0x0000000180000000
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.L4malign:.quad 0xffffffffffc00000
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.Lscan2g:.quad 0x80000000 + 0x20000 - 8 # 2GB + 128K - 8
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.Lnop: .long 0x07000700
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.Lzero64:.fill 16,4,0x0
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#ifdef CONFIG_ZFCPDUMP
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.Lcurrent_cpu:
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.long 0x0
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.Lpref_arr_ptr:
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.long zfcpdump_prefix_array
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#endif /* CONFIG_ZFCPDUMP */
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.Lparmaddr:
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.quad PARMAREA
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.align 64
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.Lduct: .long 0,0,0,0,.Lduald,0,0,0
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.long 0,0,0,0,0,0,0,0
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.align 128
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.Lduald:.rept 8
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.long 0x80000000,0,0,0 # invalid access-list entries
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.endr
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.org 0x12000
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.globl _ehead
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_ehead:
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#ifdef CONFIG_SHARED_KERNEL
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.org 0x100000
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#endif
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#
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# startup-code, running in absolute addressing mode
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#
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.globl _stext
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_stext: basr %r13,0 # get base
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.LPG3:
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# check control registers
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stctg %c0,%c15,0(%r15)
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oi 6(%r15),0x40 # enable sigp emergency signal
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oi 4(%r15),0x10 # switch on low address proctection
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lctlg %c0,%c15,0(%r15)
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lam 0,15,.Laregs-.LPG3(%r13) # load acrs needed by uaccess
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brasl %r14,start_kernel # go to C code
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#
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# We returned from start_kernel ?!? PANIK
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#
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basr %r13,0
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lpswe .Ldw-.(%r13) # load disabled wait psw
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.align 8
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.Ldw: .quad 0x0002000180000000,0x0000000000000000
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.Laregs:.long 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
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