arch/s390/kernel/head31.S

   1 /*
   2  * arch/s390/kernel/head31.S
   3  *
   4  * Copyright (C) IBM Corp. 2005,2006
   5  *
   6  *   Author(s): Hartmut Penner <hp@de.ibm.com>
   7  *              Martin Schwidefsky <schwidefsky@de.ibm.com>
   8  *              Rob van der Heij <rvdhei@iae.nl>
   9  *              Heiko Carstens <heiko.carstens@de.ibm.com>
  10  *
  11  */
  12
  13 #
  14 # startup-code at 0x10000, running in absolute addressing mode
  15 # this is called either by the ipl loader or directly by PSW restart
  16 # or linload or SALIPL
  17 #
  18         .org    0x10000
  19 startup:basr    %r13,0                  # get base
  20 .LPG0:  l       %r13,0f-.LPG0(%r13)
  21         b       0(%r13)
  22 0:      .long   startup_continue
  23
  24 #
  25 # params at 10400 (setup.h)
  26 #
  27         .org    PARMAREA
  28         .long   0,0                     # IPL_DEVICE
  29         .long   0,0                     # INITRD_START
  30         .long   0,0                     # INITRD_SIZE
  31
  32         .org    COMMAND_LINE
  33         .byte   "root=/dev/ram0 ro"
  34         .byte   0
  35
  36         .org    0x11000
  37
  38 startup_continue:
  39         basr    %r13,0                  # get base
  40 .LPG1:  mvi     __LC_AR_MODE_ID,0       # set ESA flag (mode 0)
  41         lctl    %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
  42         l       %r12,.Lparmaddr-.LPG1(%r13) # pointer to parameter area
  43                                         # move IPL device to lowcore
  44         mvc     __LC_IPLDEV(4),IPL_DEVICE-PARMAREA(%r12)
  45 #
  46 # Setup stack
  47 #
  48         l       %r15,.Linittu-.LPG1(%r13)
  49         mvc     __LC_CURRENT(4),__TI_task(%r15)
  50         ahi     %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union+THREAD_SIZE
  51         st      %r15,__LC_KERNEL_STACK  # set end of kernel stack
  52         ahi     %r15,-96
  53         xc      __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain
  54
  55         l       %r14,.Lipl_save_parameters-.LPG1(%r13)
  56         basr    %r14,%r14
  57 #
  58 # clear bss memory
  59 #
  60         l       %r2,.Lbss_bgn-.LPG1(%r13) # start of bss
  61         l       %r3,.Lbss_end-.LPG1(%r13) # end of bss
  62         sr      %r3,%r2                 # length of bss
  63         sr      %r4,%r4
  64         sr      %r5,%r5                 # set src,length and pad to zero
  65         sr      %r0,%r0
  66         mvcle   %r2,%r4,0               # clear mem
  67         jo      .-4                     # branch back, if not finish
  68
  69         l       %r2,.Lrcp-.LPG1(%r13)   # Read SCP forced command word
  70 .Lservicecall:
  71         stosm   .Lpmask-.LPG1(%r13),0x01        # authorize ext interrupts
  72
  73         stctl   %r0, %r0,.Lcr-.LPG1(%r13)       # get cr0
  74         la      %r1,0x200               # set bit 22
  75         o       %r1,.Lcr-.LPG1(%r13)    # or old cr0 with r1
  76         st      %r1,.Lcr-.LPG1(%r13)
  77         lctl    %r0, %r0,.Lcr-.LPG1(%r13)       # load modified cr0
  78
  79         mvc     __LC_EXT_NEW_PSW(8),.Lpcext-.LPG1(%r13) # set postcall psw
  80         la      %r1, .Lsclph-.LPG1(%r13)
  81         a       %r1,__LC_EXT_NEW_PSW+4  # set handler
  82         st      %r1,__LC_EXT_NEW_PSW+4
  83
  84         l       %r4,.Lsccbaddr-.LPG1(%r13) # %r4 is our index for sccb stuff
  85         lr      %r1,%r4                 # our sccb
  86         .insn   rre,0xb2200000,%r2,%r1  # service call
  87         ipm     %r1
  88         srl     %r1,28                  # get cc code
  89         xr      %r3, %r3
  90         chi     %r1,3
  91         be      .Lfchunk-.LPG1(%r13)    # leave
  92         chi     %r1,2
  93         be      .Lservicecall-.LPG1(%r13)
  94         lpsw    .Lwaitsclp-.LPG1(%r13)
  95 .Lsclph:
  96         lh      %r1,.Lsccbr-.Lsccb(%r4)
  97         chi     %r1,0x10                # 0x0010 is the sucess code
  98         je      .Lprocsccb              # let's process the sccb
  99         chi     %r1,0x1f0
 100         bne     .Lfchunk-.LPG1(%r13)    # unhandled error code
 101         c       %r2, .Lrcp-.LPG1(%r13)  # Did we try Read SCP forced
 102         bne     .Lfchunk-.LPG1(%r13)    # if no, give up
 103         l       %r2, .Lrcp2-.LPG1(%r13) # try with Read SCP
 104         b       .Lservicecall-.LPG1(%r13)
 105 .Lprocsccb:
 106         lhi     %r1,0
 107         icm     %r1,3,.Lscpincr1-.Lsccb(%r4) # use this one if != 0
 108         jnz     .Lscnd
 109         lhi     %r1,0x800               # otherwise report 2GB
 110 .Lscnd:
 111         lhi     %r3,0x800               # limit reported memory size to 2GB
 112         cr      %r1,%r3
 113         jl      .Lno2gb
 114         lr      %r1,%r3
 115 .Lno2gb:
 116         xr      %r3,%r3                 # same logic
 117         ic      %r3,.Lscpa1-.Lsccb(%r4)
 118         chi     %r3,0x00
 119         jne     .Lcompmem
 120         l       %r3,.Lscpa2-.Lsccb(%r4)
 121 .Lcompmem:
 122         mr      %r2,%r1                 # mem in MB on 128-bit
 123         l       %r1,.Lonemb-.LPG1(%r13)
 124         mr      %r2,%r1                 # mem size in bytes in %r3
 125         b       .Lfchunk-.LPG1(%r13)
 126
 127         .align 4
 128 .Lipl_save_parameters:
 129         .long   ipl_save_parameters
 130 .Linittu:
 131         .long   init_thread_union
 132 .Lpmask:
 133         .byte   0
 134 .align 8
 135 .Lpcext:.long   0x00080000,0x80000000
 136 .Lcr:
 137         .long   0x00                    # place holder for cr0
 138 .Lwaitsclp:
 139         .long 0x010a0000,0x80000000 + .Lsclph
 140 .Lrcp:
 141         .int    0x00120001              # Read SCP forced code
 142 .Lrcp2:
 143         .int    0x00020001              # Read SCP code
 144 .Lonemb:
 145         .int    0x100000
 146 .Lfchunk:
 147
 148 #
 149 # find memory chunks.
 150 #
 151         lr      %r9,%r3                 # end of mem
 152         mvc     __LC_PGM_NEW_PSW(8),.Lpcmem-.LPG1(%r13)
 153         la      %r1,1                   # test in increments of 128KB
 154         sll     %r1,17
 155         l       %r3,.Lmchunk-.LPG1(%r13) # get pointer to memory_chunk array
 156         slr     %r4,%r4                 # set start of chunk to zero
 157         slr     %r5,%r5                 # set end of chunk to zero
 158         slr     %r6,%r6                 # set access code to zero
 159         la      %r10, MEMORY_CHUNKS     # number of chunks
 160 .Lloop:
 161         tprot   0(%r5),0                # test protection of first byte
 162         ipm     %r7
 163         srl     %r7,28
 164         clr     %r6,%r7                 # compare cc with last access code
 165         be      .Lsame-.LPG1(%r13)
 166         b       .Lchkmem-.LPG1(%r13)
 167 .Lsame:
 168         ar      %r5,%r1                 # add 128KB to end of chunk
 169         bno     .Lloop-.LPG1(%r13)      # r1 < 0x80000000 -> loop
 170 .Lchkmem:                               # > 2GB or tprot got a program check
 171         clr     %r4,%r5                 # chunk size > 0?
 172         be      .Lchkloop-.LPG1(%r13)
 173         st      %r4,0(%r3)              # store start address of chunk
 174         lr      %r0,%r5
 175         slr     %r0,%r4
 176         st      %r0,4(%r3)              # store size of chunk
 177         st      %r6,8(%r3)              # store type of chunk
 178         la      %r3,12(%r3)
 179         l       %r4,.Lmemsize-.LPG1(%r13)        # address of variable memory_size
 180         st      %r5,0(%r4)              # store last end to memory size
 181         ahi     %r10,-1                 # update chunk number
 182 .Lchkloop:
 183         lr      %r6,%r7                 # set access code to last cc
 184         # we got an exception or we're starting a new
 185         # chunk , we must check if we should
 186         # still try to find valid memory (if we detected
 187         # the amount of available storage), and if we
 188         # have chunks left
 189         xr      %r0,%r0
 190         clr     %r0,%r9                 # did we detect memory?
 191         je      .Ldonemem               # if not, leave
 192         chi     %r10,0                  # do we have chunks left?
 193         je      .Ldonemem
 194         alr     %r5,%r1                 # add 128KB to end of chunk
 195         lr      %r4,%r5                 # potential new chunk
 196         clr     %r5,%r9                 # should we go on?
 197         jl      .Lloop
 198 .Ldonemem:
 199         l       %r12,.Lmflags-.LPG1(%r13) # get address of machine_flags
 200 #
 201 # find out if we are running under VM
 202 #
 203         stidp   __LC_CPUID              # store cpuid
 204         tm      __LC_CPUID,0xff         # running under VM ?
 205         bno     .Lnovm-.LPG1(%r13)
 206         oi      3(%r12),1               # set VM flag
 207 .Lnovm:
 208         lh      %r0,__LC_CPUID+4        # get cpu version
 209         chi     %r0,0x7490              # running on a P/390 ?
 210         bne     .Lnop390-.LPG1(%r13)
 211         oi      3(%r12),4               # set P/390 flag
 212 .Lnop390:
 213
 214 #
 215 # find out if we have an IEEE fpu
 216 #
 217         mvc     __LC_PGM_NEW_PSW(8),.Lpcfpu-.LPG1(%r13)
 218         efpc    %r0,0                   # test IEEE extract fpc instruction
 219         oi      3(%r12),2               # set IEEE fpu flag
 220 .Lchkfpu:
 221
 222 #
 223 # find out if we have the CSP instruction
 224 #
 225        mvc       __LC_PGM_NEW_PSW(8),.Lpccsp-.LPG1(%r13)
 226        la        %r0,0
 227        lr       %r1,%r0
 228        la       %r2,4
 229        csp      %r0,%r2                 # Test CSP instruction
 230        oi       3(%r12),8               # set CSP flag
 231 .Lchkcsp:
 232
 233 #
 234 # find out if we have the MVPG instruction
 235 #
 236        mvc      __LC_PGM_NEW_PSW(8),.Lpcmvpg-.LPG1(%r13)
 237        sr       %r0,%r0
 238        la       %r1,0
 239        la       %r2,0
 240        mvpg     %r1,%r2                 # Test CSP instruction
 241        oi       3(%r12),16              # set MVPG flag
 242 .Lchkmvpg:
 243
 244 #
 245 # find out if we have the IDTE instruction
 246 #
 247         mvc     __LC_PGM_NEW_PSW(8),.Lpcidte-.LPG1(%r13)
 248         .long   0xb2b10000              # store facility list
 249         tm      0xc8,0x08               # check bit for clearing-by-ASCE
 250         bno     .Lchkidte-.LPG1(%r13)
 251         lhi     %r1,2094
 252         lhi     %r2,0
 253         .long   0xb98e2001
 254         oi      3(%r12),0x80            # set IDTE flag
 255 .Lchkidte:
 256
 257 #
 258 # find out if the diag 0x9c is available
 259 #
 260         mvc     __LC_PGM_NEW_PSW(8),.Lpcdiag9c-.LPG1(%r13)
 261         stap   __LC_CPUID+4             # store cpu address
 262         lh     %r1,__LC_CPUID+4
 263         diag   %r1,0,0x9c               # test diag 0x9c
 264         oi     2(%r12),1                # set diag9c flag
 265 .Lchkdiag9c:
 266
 267         lpsw  .Lentry-.LPG1(13)         # jump to _stext in primary-space,
 268                                         # virtual and never return ...
 269         .align  8
 270 .Lentry:.long   0x00080000,0x80000000 + _stext
 271 .Lctl:  .long   0x04b50002              # cr0: various things
 272         .long   0                       # cr1: primary space segment table
 273         .long   .Lduct                  # cr2: dispatchable unit control table
 274         .long   0                       # cr3: instruction authorization
 275         .long   0                       # cr4: instruction authorization
 276         .long   0xffffffff              # cr5: primary-aste origin
 277         .long   0                       # cr6:  I/O interrupts
 278         .long   0                       # cr7:  secondary space segment table
 279         .long   0                       # cr8:  access registers translation
 280         .long   0                       # cr9:  tracing off
 281         .long   0                       # cr10: tracing off
 282         .long   0                       # cr11: tracing off
 283         .long   0                       # cr12: tracing off
 284         .long   0                       # cr13: home space segment table
 285         .long   0xc0000000              # cr14: machine check handling off
 286         .long   0                       # cr15: linkage stack operations
 287 .Lduct: .long   0,0,0,0,0,0,0,0
 288         .long   0,0,0,0,0,0,0,0
 289 .Lpcmem:.long   0x00080000,0x80000000 + .Lchkmem
 290 .Lpcfpu:.long   0x00080000,0x80000000 + .Lchkfpu
 291 .Lpccsp:.long   0x00080000,0x80000000 + .Lchkcsp
 292 .Lpcmvpg:.long  0x00080000,0x80000000 + .Lchkmvpg
 293 .Lpcidte:.long  0x00080000,0x80000000 + .Lchkidte
 294 .Lpcdiag9c:.long 0x00080000,0x80000000 + .Lchkdiag9c
 295 .Lmemsize:.long memory_size
 296 .Lmchunk:.long  memory_chunk
 297 .Lmflags:.long  machine_flags
 298 .Lbss_bgn:  .long __bss_start
 299 .Lbss_end:  .long _end
 300 .Lparmaddr: .long PARMAREA
 301 .Lsccbaddr: .long .Lsccb
 302
 303         .globl ipl_schib
 304 ipl_schib:
 305         .rept 13
 306         .long 0
 307         .endr
 308
 309         .globl ipl_flags
 310 ipl_flags:
 311         .long 0
 312         .globl ipl_devno
 313 ipl_devno:
 314         .word 0
 315
 316         .org    0x12000
 317 .globl s390_readinfo_sccb
 318 s390_readinfo_sccb:
 319 .Lsccb:
 320         .hword  0x1000                  # length, one page
 321         .byte   0x00,0x00,0x00
 322         .byte   0x80                    # variable response bit set
 323 .Lsccbr:
 324         .hword  0x00                    # response code
 325 .Lscpincr1:
 326         .hword  0x00
 327 .Lscpa1:
 328         .byte   0x00
 329         .fill   89,1,0
 330 .Lscpa2:
 331         .int    0x00
 332 .Lscpincr2:
 333         .quad   0x00
 334         .fill   3984,1,0
 335         .org    0x13000
 336
 337 #ifdef CONFIG_SHARED_KERNEL
 338         .org    0x100000
 339 #endif
 340
 341 #
 342 # startup-code, running in absolute addressing mode
 343 #
 344         .globl  _stext
 345 _stext: basr    %r13,0                  # get base
 346 .LPG3:
 347 # check control registers
 348         stctl   %c0,%c15,0(%r15)
 349         oi      2(%r15),0x40            # enable sigp emergency signal
 350         oi      0(%r15),0x10            # switch on low address protection
 351         lctl    %c0,%c15,0(%r15)
 352
 353 #
 354         lam     0,15,.Laregs-.LPG3(%r13) # load access regs needed by uaccess
 355         l       %r14,.Lstart-.LPG3(%r13)
 356         basr    %r14,%r14               # call start_kernel
 357 #
 358 # We returned from start_kernel ?!? PANIK
 359 #
 360         basr    %r13,0
 361         lpsw    .Ldw-.(%r13)            # load disabled wait psw
 362 #
 363         .align  8
 364 .Ldw:   .long   0x000a0000,0x00000000
 365 .Lstart:.long   start_kernel
 366 .Laregs:.long   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0