arch/s390/kernel/sclp.S

   1 /*
   2  * Mini SCLP driver.
   3  *
   4  * Copyright IBM Corp. 2004,2009
   5  *
   6  *   Author(s): Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com>,
   7  *              Heiko Carstens <heiko.carstens@de.ibm.com>,
   8  *
   9  */
  10
  11 LC_EXT_NEW_PSW          = 0x58                  # addr of ext int handler
  12 LC_EXT_INT_PARAM        = 0x80                  # addr of ext int parameter
  13 LC_EXT_INT_CODE         = 0x86                  # addr of ext int code
  14
  15 #
  16 # Subroutine which waits synchronously until either an external interruption
  17 # or a timeout occurs.
  18 #
  19 # Parameters:
  20 #   R2  = 0 for no timeout, non-zero for timeout in (approximated) seconds
  21 #
  22 # Returns:
  23 #   R2  = 0 on interrupt, 2 on timeout
  24 #   R3  = external interruption parameter if R2=0
  25 #
  26
  27 .section ".init.text","ax"
  28
  29 _sclp_wait_int:
  30         stm     %r6,%r15,24(%r15)               # save registers
  31         basr    %r13,0                          # get base register
  32 .LbaseS1:
  33         ahi     %r15,-96                        # create stack frame
  34         la      %r8,LC_EXT_NEW_PSW              # register int handler
  35         mvc     .LoldpswS1-.LbaseS1(8,%r13),0(%r8)
  36         mvc     0(8,%r8),.LextpswS1-.LbaseS1(%r13)
  37         lhi     %r6,0x0200                      # cr mask for ext int (cr0.54)
  38         ltr     %r2,%r2
  39         jz      .LsetctS1
  40         ahi     %r6,0x0800                      # cr mask for clock int (cr0.52)
  41         stck    .LtimeS1-.LbaseS1(%r13)         # initiate timeout
  42         al      %r2,.LtimeS1-.LbaseS1(%r13)
  43         st      %r2,.LtimeS1-.LbaseS1(%r13)
  44         sckc    .LtimeS1-.LbaseS1(%r13)
  45
  46 .LsetctS1:
  47         stctl   %c0,%c0,.LctlS1-.LbaseS1(%r13)  # enable required interrupts
  48         l       %r0,.LctlS1-.LbaseS1(%r13)
  49         lhi     %r1,~(0x200 | 0x800)            # clear old values
  50         nr      %r1,%r0
  51         or      %r1,%r6                         # set new value
  52         st      %r1,.LctlS1-.LbaseS1(%r13)
  53         lctl    %c0,%c0,.LctlS1-.LbaseS1(%r13)
  54         st      %r0,.LctlS1-.LbaseS1(%r13)
  55         lhi     %r2,2                           # return code for timeout
  56 .LloopS1:
  57         lpsw    .LwaitpswS1-.LbaseS1(%r13)      # wait until interrupt
  58 .LwaitS1:
  59         lh      %r7,LC_EXT_INT_CODE
  60         chi     %r7,0x1004                      # timeout?
  61         je      .LtimeoutS1
  62         chi     %r7,0x2401                      # service int?
  63         jne     .LloopS1
  64         sr      %r2,%r2
  65         l       %r3,LC_EXT_INT_PARAM
  66 .LtimeoutS1:
  67         lctl    %c0,%c0,.LctlS1-.LbaseS1(%r13)  # restore interrupt setting
  68         # restore old handler
  69         mvc     0(8,%r8),.LoldpswS1-.LbaseS1(%r13)
  70         lm      %r6,%r15,120(%r15)              # restore registers
  71         br      %r14                            # return to caller
  72
  73         .align  8
  74 .LoldpswS1:
  75         .long   0, 0                            # old ext int PSW
  76 .LextpswS1:
  77         .long   0x00080000, 0x80000000+.LwaitS1 # PSW to handle ext int
  78 .LwaitpswS1:
  79         .long   0x010a0000, 0x00000000+.LloopS1 # PSW to wait for ext int
  80 .LtimeS1:
  81         .quad   0                               # current time
  82 .LctlS1:
  83         .long   0                               # CT0 contents
  84
  85 #
  86 # Subroutine to synchronously issue a service call.
  87 #
  88 # Parameters:
  89 #   R2  = command word
  90 #   R3  = sccb address
  91 #
  92 # Returns:
  93 #   R2  = 0 on success, 1 on failure
  94 #   R3  = sccb response code if R2 = 0
  95 #
  96
  97 _sclp_servc:
  98         stm     %r6,%r15,24(%r15)               # save registers
  99         ahi     %r15,-96                        # create stack frame
 100         lr      %r6,%r2                         # save command word
 101         lr      %r7,%r3                         # save sccb address
 102 .LretryS2:
 103         lhi     %r2,1                           # error return code
 104         .insn   rre,0xb2200000,%r6,%r7          # servc
 105         brc     1,.LendS2                       # exit if not operational
 106         brc     8,.LnotbusyS2                   # go on if not busy
 107         sr      %r2,%r2                         # wait until no longer busy
 108         bras    %r14,_sclp_wait_int
 109         j       .LretryS2                       # retry
 110 .LnotbusyS2:
 111         sr      %r2,%r2                         # wait until result
 112         bras    %r14,_sclp_wait_int
 113         sr      %r2,%r2
 114         lh      %r3,6(%r7)
 115 .LendS2:
 116         lm      %r6,%r15,120(%r15)              # restore registers
 117         br      %r14
 118
 119 #
 120 # Subroutine to set up the SCLP interface.
 121 #
 122 # Parameters:
 123 #   R2  = 0 to activate, non-zero to deactivate
 124 #
 125 # Returns:
 126 #   R2  = 0 on success, non-zero on failure
 127 #
 128
 129 _sclp_setup:
 130         stm     %r6,%r15,24(%r15)               # save registers
 131         ahi     %r15,-96                        # create stack frame
 132         basr    %r13,0                          # get base register
 133 .LbaseS3:
 134         l       %r6,.LsccbS0-.LbaseS3(%r13)     # prepare init mask sccb
 135         mvc     0(.LinitendS3-.LinitsccbS3,%r6),.LinitsccbS3-.LbaseS3(%r13)
 136         ltr     %r2,%r2                         # initialization?
 137         jz      .LdoinitS3                      # go ahead
 138         # clear masks
 139         xc      .LinitmaskS3-.LinitsccbS3(8,%r6),.LinitmaskS3-.LinitsccbS3(%r6)
 140 .LdoinitS3:
 141         l       %r2,.LwritemaskS3-.LbaseS3(%r13)# get command word
 142         lr      %r3,%r6                         # get sccb address
 143         bras    %r14,_sclp_servc                # issue service call
 144         ltr     %r2,%r2                         # servc successful?
 145         jnz     .LerrorS3
 146         chi     %r3,0x20                        # write mask successful?
 147         jne     .LerrorS3
 148         # check masks
 149         la      %r2,.LinitmaskS3-.LinitsccbS3(%r6)
 150         l       %r1,0(%r2)                      # receive mask ok?
 151         n       %r1,12(%r2)
 152         cl      %r1,0(%r2)
 153         jne     .LerrorS3
 154         l       %r1,4(%r2)                      # send mask ok?
 155         n       %r1,8(%r2)
 156         cl      %r1,4(%r2)
 157         sr      %r2,%r2
 158         je      .LendS3
 159 .LerrorS3:
 160         lhi     %r2,1                           # error return code
 161 .LendS3:
 162         lm      %r6,%r15,120(%r15)              # restore registers
 163         br      %r14
 164 .LwritemaskS3:
 165         .long   0x00780005                      # SCLP command for write mask
 166 .LinitsccbS3:
 167         .word   .LinitendS3-.LinitsccbS3
 168         .byte   0,0,0,0
 169         .word   0
 170         .word   0
 171         .word   4
 172 .LinitmaskS3:
 173         .long   0x80000000
 174         .long   0x40000000
 175         .long   0
 176         .long   0
 177 .LinitendS3:
 178
 179 #
 180 # Subroutine which prints a given text to the SCLP console.
 181 #
 182 # Parameters:
 183 #   R2  = address of nil-terminated ASCII text
 184 #
 185 # Returns:
 186 #   R2  = 0 on success, 1 on failure
 187 #
 188
 189 _sclp_print:
 190         stm     %r6,%r15,24(%r15)               # save registers
 191         ahi     %r15,-96                        # create stack frame
 192         basr    %r13,0                          # get base register
 193 .LbaseS4:
 194         l       %r8,.LsccbS0-.LbaseS4(%r13)     # prepare write data sccb
 195         mvc     0(.LmtoS4-.LwritesccbS4,%r8),.LwritesccbS4-.LbaseS4(%r13)
 196         la      %r7,.LmtoS4-.LwritesccbS4(%r8)  # current mto addr
 197         sr      %r0,%r0
 198         l       %r10,.Lascebc-.LbaseS4(%r13)    # address of translation table
 199 .LinitmtoS4:
 200         # initialize mto
 201         mvc     0(.LmtoendS4-.LmtoS4,%r7),.LmtoS4-.LbaseS4(%r13)
 202         lhi     %r6,.LmtoendS4-.LmtoS4          # current mto length
 203 .LloopS4:
 204         ic      %r0,0(%r2)                      # get character
 205         ahi     %r2,1
 206         ltr     %r0,%r0                         # end of string?
 207         jz      .LfinalizemtoS4
 208         chi     %r0,0x15                        # end of line (NL)?
 209         jz      .LfinalizemtoS4
 210         stc     %r0,0(%r6,%r7)                  # copy to mto
 211         la      %r11,0(%r6,%r7)
 212         tr      0(1,%r11),0(%r10)               # translate to EBCDIC
 213         ahi     %r6,1
 214         j       .LloopS4
 215 .LfinalizemtoS4:
 216         sth     %r6,0(%r7)                      # update mto length
 217         lh      %r9,.LmdbS4-.LwritesccbS4(%r8)  # update mdb length
 218         ar      %r9,%r6
 219         sth     %r9,.LmdbS4-.LwritesccbS4(%r8)
 220         lh      %r9,.LevbufS4-.LwritesccbS4(%r8)# update evbuf length
 221         ar      %r9,%r6
 222         sth     %r9,.LevbufS4-.LwritesccbS4(%r8)
 223         lh      %r9,0(%r8)                      # update sccb length
 224         ar      %r9,%r6
 225         sth     %r9,0(%r8)
 226         ar      %r7,%r6                         # update current mto adress
 227         ltr     %r0,%r0                         # more characters?
 228         jnz     .LinitmtoS4
 229         l       %r2,.LwritedataS4-.LbaseS4(%r13)# write data
 230         lr      %r3,%r8
 231         bras    %r14,_sclp_servc
 232         ltr     %r2,%r2                         # servc successful?
 233         jnz     .LendS4
 234         chi     %r3,0x20                        # write data successful?
 235         je      .LendS4
 236         lhi     %r2,1                           # error return code
 237 .LendS4:
 238         lm      %r6,%r15,120(%r15)              # restore registers
 239         br      %r14
 240
 241 #
 242 # Function which prints a given text to the SCLP console.
 243 #
 244 # Parameters:
 245 #   R2  = address of nil-terminated ASCII text
 246 #
 247 # Returns:
 248 #   R2  = 0 on success, 1 on failure
 249 #
 250
 251         .globl _sclp_print_early
 252 _sclp_print_early:
 253         stm     %r6,%r15,24(%r15)               # save registers
 254         ahi     %r15,-96                        # create stack frame
 255         lr      %r10,%r2                        # save string pointer
 256         lhi     %r2,0
 257         bras    %r14,_sclp_setup                # enable console
 258         ltr     %r2,%r2
 259         jnz     .LendS5
 260         lr      %r2,%r10
 261         bras    %r14,_sclp_print                # print string
 262         ltr     %r2,%r2
 263         jnz     .LendS5
 264         lhi     %r2,1
 265         bras    %r14,_sclp_setup                # disable console
 266 .LendS5:
 267         lm      %r6,%r15,120(%r15)              # restore registers
 268         br      %r14
 269
 270 .LwritedataS4:
 271         .long   0x00760005                      # SCLP command for write data
 272 .LwritesccbS4:
 273         # sccb
 274         .word   .LmtoS4-.LwritesccbS4
 275         .byte   0
 276         .byte   0,0,0
 277         .word   0
 278
 279         # evbuf
 280 .LevbufS4:
 281         .word   .LmtoS4-.LevbufS4
 282         .byte   0x02
 283         .byte   0
 284         .word   0
 285
 286 .LmdbS4:
 287         # mdb
 288         .word   .LmtoS4-.LmdbS4
 289         .word   1
 290         .long   0xd4c4c240
 291         .long   1
 292
 293         # go
 294 .LgoS4:
 295         .word   .LmtoS4-.LgoS4
 296         .word   1
 297         .long   0
 298         .byte   0,0,0,0,0,0,0,0
 299         .byte   0,0,0
 300         .byte   0
 301         .byte   0,0,0,0,0,0,0
 302         .byte   0
 303         .word   0
 304         .byte   0,0,0,0,0,0,0,0,0,0
 305         .byte   0,0,0,0,0,0,0,0
 306         .byte   0,0,0,0,0,0,0,0
 307
 308 .LmtoS4:
 309         .word   .LmtoendS4-.LmtoS4
 310         .word   4
 311         .word   0x1000
 312         .byte   0
 313         .byte   0,0,0
 314 .LmtoendS4:
 315
 316         # Global constants
 317 .LsccbS0:
 318         .long   _sclp_work_area
 319 .Lascebc:
 320         .long   _ascebc
 321 .previous
 322
 323 .section ".init.data","a"
 324         .balign 4096
 325 _sclp_work_area:
 326         .fill   4096
 327 .previous