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 #include <linux/linkage.h>
  12
  13 LC_EXT_NEW_PSW          = 0x58                  # addr of ext int handler
  14 LC_EXT_NEW_PSW_64       = 0x1b0                 # addr of ext int handler 64 bit
  15 LC_EXT_INT_PARAM        = 0x80                  # addr of ext int parameter
  16 LC_EXT_INT_CODE         = 0x86                  # addr of ext int code
  17 LC_AR_MODE_ID           = 0xa3
  18
  19 #
  20 # Subroutine which waits synchronously until either an external interruption
  21 # or a timeout occurs.
  22 #
  23 # Parameters:
  24 #   R2  = 0 for no timeout, non-zero for timeout in (approximated) seconds
  25 #
  26 # Returns:
  27 #   R2  = 0 on interrupt, 2 on timeout
  28 #   R3  = external interruption parameter if R2=0
  29 #
  30
  31 _sclp_wait_int:
  32         stm     %r6,%r15,24(%r15)               # save registers
  33         basr    %r13,0                          # get base register
  34 .LbaseS1:
  35         ahi     %r15,-96                        # create stack frame
  36         la      %r8,LC_EXT_NEW_PSW              # register int handler
  37         la      %r9,.LextpswS1-.LbaseS1(%r13)
  38 #ifdef CONFIG_64BIT
  39         tm      LC_AR_MODE_ID,1
  40         jno     .Lesa1
  41         la      %r8,LC_EXT_NEW_PSW_64           # register int handler 64 bit
  42         la      %r9,.LextpswS1_64-.LbaseS1(%r13)
  43 .Lesa1:
  44 #endif
  45         mvc     .LoldpswS1-.LbaseS1(16,%r13),0(%r8)
  46         mvc     0(16,%r8),0(%r9)
  47 #ifdef CONFIG_64BIT
  48         epsw    %r6,%r7                         # set current addressing mode
  49         nill    %r6,0x1                         # in new psw (31 or 64 bit mode)
  50         nilh    %r7,0x8000
  51         stm     %r6,%r7,0(%r8)
  52 #endif
  53         lhi     %r6,0x0200                      # cr mask for ext int (cr0.54)
  54         ltr     %r2,%r2
  55         jz      .LsetctS1
  56         ahi     %r6,0x0800                      # cr mask for clock int (cr0.52)
  57         stck    .LtimeS1-.LbaseS1(%r13)         # initiate timeout
  58         al      %r2,.LtimeS1-.LbaseS1(%r13)
  59         st      %r2,.LtimeS1-.LbaseS1(%r13)
  60         sckc    .LtimeS1-.LbaseS1(%r13)
  61
  62 .LsetctS1:
  63         stctl   %c0,%c0,.LctlS1-.LbaseS1(%r13)  # enable required interrupts
  64         l       %r0,.LctlS1-.LbaseS1(%r13)
  65         lhi     %r1,~(0x200 | 0x800)            # clear old values
  66         nr      %r1,%r0
  67         or      %r1,%r6                         # set new value
  68         st      %r1,.LctlS1-.LbaseS1(%r13)
  69         lctl    %c0,%c0,.LctlS1-.LbaseS1(%r13)
  70         st      %r0,.LctlS1-.LbaseS1(%r13)
  71         lhi     %r2,2                           # return code for timeout
  72 .LloopS1:
  73         lpsw    .LwaitpswS1-.LbaseS1(%r13)      # wait until interrupt
  74 .LwaitS1:
  75         lh      %r7,LC_EXT_INT_CODE
  76         chi     %r7,0x1004                      # timeout?
  77         je      .LtimeoutS1
  78         chi     %r7,0x2401                      # service int?
  79         jne     .LloopS1
  80         sr      %r2,%r2
  81         l       %r3,LC_EXT_INT_PARAM
  82 .LtimeoutS1:
  83         lctl    %c0,%c0,.LctlS1-.LbaseS1(%r13)  # restore interrupt setting
  84         # restore old handler
  85         mvc     0(16,%r8),.LoldpswS1-.LbaseS1(%r13)
  86         lm      %r6,%r15,120(%r15)              # restore registers
  87         br      %r14                            # return to caller
  88
  89         .align  8
  90 .LoldpswS1:
  91         .long   0, 0, 0, 0                      # old ext int PSW
  92 .LextpswS1:
  93         .long   0x00080000, 0x80000000+.LwaitS1 # PSW to handle ext int
  94 #ifdef CONFIG_64BIT
  95 .LextpswS1_64:
  96         .quad   0, .LwaitS1                     # PSW to handle ext int, 64 bit
  97 #endif
  98 .LwaitpswS1:
  99         .long   0x010a0000, 0x00000000+.LloopS1 # PSW to wait for ext int
 100 .LtimeS1:
 101         .quad   0                               # current time
 102 .LctlS1:
 103         .long   0                               # CT0 contents
 104
 105 #
 106 # Subroutine to synchronously issue a service call.
 107 #
 108 # Parameters:
 109 #   R2  = command word
 110 #   R3  = sccb address
 111 #
 112 # Returns:
 113 #   R2  = 0 on success, 1 on failure
 114 #   R3  = sccb response code if R2 = 0
 115 #
 116
 117 _sclp_servc:
 118         stm     %r6,%r15,24(%r15)               # save registers
 119         ahi     %r15,-96                        # create stack frame
 120         lr      %r6,%r2                         # save command word
 121         lr      %r7,%r3                         # save sccb address
 122 .LretryS2:
 123         lhi     %r2,1                           # error return code
 124         .insn   rre,0xb2200000,%r6,%r7          # servc
 125         brc     1,.LendS2                       # exit if not operational
 126         brc     8,.LnotbusyS2                   # go on if not busy
 127         sr      %r2,%r2                         # wait until no longer busy
 128         bras    %r14,_sclp_wait_int
 129         j       .LretryS2                       # retry
 130 .LnotbusyS2:
 131         sr      %r2,%r2                         # wait until result
 132         bras    %r14,_sclp_wait_int
 133         sr      %r2,%r2
 134         lh      %r3,6(%r7)
 135 .LendS2:
 136         lm      %r6,%r15,120(%r15)              # restore registers
 137         br      %r14
 138
 139 #
 140 # Subroutine to set up the SCLP interface.
 141 #
 142 # Parameters:
 143 #   R2  = 0 to activate, non-zero to deactivate
 144 #
 145 # Returns:
 146 #   R2  = 0 on success, non-zero on failure
 147 #
 148
 149 _sclp_setup:
 150         stm     %r6,%r15,24(%r15)               # save registers
 151         ahi     %r15,-96                        # create stack frame
 152         basr    %r13,0                          # get base register
 153 .LbaseS3:
 154         l       %r6,.LsccbS0-.LbaseS3(%r13)     # prepare init mask sccb
 155         mvc     0(.LinitendS3-.LinitsccbS3,%r6),.LinitsccbS3-.LbaseS3(%r13)
 156         ltr     %r2,%r2                         # initialization?
 157         jz      .LdoinitS3                      # go ahead
 158         # clear masks
 159         xc      .LinitmaskS3-.LinitsccbS3(8,%r6),.LinitmaskS3-.LinitsccbS3(%r6)
 160 .LdoinitS3:
 161         l       %r2,.LwritemaskS3-.LbaseS3(%r13)# get command word
 162         lr      %r3,%r6                         # get sccb address
 163         bras    %r14,_sclp_servc                # issue service call
 164         ltr     %r2,%r2                         # servc successful?
 165         jnz     .LerrorS3
 166         chi     %r3,0x20                        # write mask successful?
 167         jne     .LerrorS3
 168         # check masks
 169         la      %r2,.LinitmaskS3-.LinitsccbS3(%r6)
 170         l       %r1,0(%r2)                      # receive mask ok?
 171         n       %r1,12(%r2)
 172         cl      %r1,0(%r2)
 173         jne     .LerrorS3
 174         l       %r1,4(%r2)                      # send mask ok?
 175         n       %r1,8(%r2)
 176         cl      %r1,4(%r2)
 177         sr      %r2,%r2
 178         je      .LendS3
 179 .LerrorS3:
 180         lhi     %r2,1                           # error return code
 181 .LendS3:
 182         lm      %r6,%r15,120(%r15)              # restore registers
 183         br      %r14
 184 .LwritemaskS3:
 185         .long   0x00780005                      # SCLP command for write mask
 186 .LinitsccbS3:
 187         .word   .LinitendS3-.LinitsccbS3
 188         .byte   0,0,0,0
 189         .word   0
 190         .word   0
 191         .word   4
 192 .LinitmaskS3:
 193         .long   0x80000000
 194         .long   0x40000000
 195         .long   0
 196         .long   0
 197 .LinitendS3:
 198
 199 #
 200 # Subroutine which prints a given text to the SCLP console.
 201 #
 202 # Parameters:
 203 #   R2  = address of nil-terminated ASCII text
 204 #
 205 # Returns:
 206 #   R2  = 0 on success, 1 on failure
 207 #
 208
 209 _sclp_print:
 210         stm     %r6,%r15,24(%r15)               # save registers
 211         ahi     %r15,-96                        # create stack frame
 212         basr    %r13,0                          # get base register
 213 .LbaseS4:
 214         l       %r8,.LsccbS0-.LbaseS4(%r13)     # prepare write data sccb
 215         mvc     0(.LmtoS4-.LwritesccbS4,%r8),.LwritesccbS4-.LbaseS4(%r13)
 216         la      %r7,.LmtoS4-.LwritesccbS4(%r8)  # current mto addr
 217         sr      %r0,%r0
 218         l       %r10,.Lascebc-.LbaseS4(%r13)    # address of translation table
 219 .LinitmtoS4:
 220         # initialize mto
 221         mvc     0(.LmtoendS4-.LmtoS4,%r7),.LmtoS4-.LbaseS4(%r13)
 222         lhi     %r6,.LmtoendS4-.LmtoS4          # current mto length
 223 .LloopS4:
 224         ic      %r0,0(%r2)                      # get character
 225         ahi     %r2,1
 226         ltr     %r0,%r0                         # end of string?
 227         jz      .LfinalizemtoS4
 228         chi     %r0,0x15                        # end of line (NL)?
 229         jz      .LfinalizemtoS4
 230         stc     %r0,0(%r6,%r7)                  # copy to mto
 231         la      %r11,0(%r6,%r7)
 232         tr      0(1,%r11),0(%r10)               # translate to EBCDIC
 233         ahi     %r6,1
 234         j       .LloopS4
 235 .LfinalizemtoS4:
 236         sth     %r6,0(%r7)                      # update mto length
 237         lh      %r9,.LmdbS4-.LwritesccbS4(%r8)  # update mdb length
 238         ar      %r9,%r6
 239         sth     %r9,.LmdbS4-.LwritesccbS4(%r8)
 240         lh      %r9,.LevbufS4-.LwritesccbS4(%r8)# update evbuf length
 241         ar      %r9,%r6
 242         sth     %r9,.LevbufS4-.LwritesccbS4(%r8)
 243         lh      %r9,0(%r8)                      # update sccb length
 244         ar      %r9,%r6
 245         sth     %r9,0(%r8)
 246         ar      %r7,%r6                         # update current mto address
 247         ltr     %r0,%r0                         # more characters?
 248         jnz     .LinitmtoS4
 249         l       %r2,.LwritedataS4-.LbaseS4(%r13)# write data
 250         lr      %r3,%r8
 251         bras    %r14,_sclp_servc
 252         ltr     %r2,%r2                         # servc successful?
 253         jnz     .LendS4
 254         chi     %r3,0x20                        # write data successful?
 255         je      .LendS4
 256         lhi     %r2,1                           # error return code
 257 .LendS4:
 258         lm      %r6,%r15,120(%r15)              # restore registers
 259         br      %r14
 260
 261 #
 262 # Function which prints a given text to the SCLP console.
 263 #
 264 # Parameters:
 265 #   R2  = address of nil-terminated ASCII text
 266 #
 267 # Returns:
 268 #   R2  = 0 on success, 1 on failure
 269 #
 270
 271 ENTRY(_sclp_print_early)
 272         stm     %r6,%r15,24(%r15)               # save registers
 273         ahi     %r15,-96                        # create stack frame
 274 #ifdef CONFIG_64BIT
 275         tm      LC_AR_MODE_ID,1
 276         jno     .Lesa2
 277         ahi     %r15,-80
 278         stmh    %r6,%r15,96(%r15)               # store upper register halves
 279 .Lesa2:
 280 #endif
 281         lr      %r10,%r2                        # save string pointer
 282         lhi     %r2,0
 283         bras    %r14,_sclp_setup                # enable console
 284         ltr     %r2,%r2
 285         jnz     .LendS5
 286         lr      %r2,%r10
 287         bras    %r14,_sclp_print                # print string
 288         ltr     %r2,%r2
 289         jnz     .LendS5
 290         lhi     %r2,1
 291         bras    %r14,_sclp_setup                # disable console
 292 .LendS5:
 293 #ifdef CONFIG_64BIT
 294         tm      LC_AR_MODE_ID,1
 295         jno     .Lesa3
 296         lmh     %r6,%r15,96(%r15)               # store upper register halves
 297         ahi     %r15,80
 298 .Lesa3:
 299 #endif
 300         lm      %r6,%r15,120(%r15)              # restore registers
 301         br      %r14
 302
 303 .LwritedataS4:
 304         .long   0x00760005                      # SCLP command for write data
 305 .LwritesccbS4:
 306         # sccb
 307         .word   .LmtoS4-.LwritesccbS4
 308         .byte   0
 309         .byte   0,0,0
 310         .word   0
 311
 312         # evbuf
 313 .LevbufS4:
 314         .word   .LmtoS4-.LevbufS4
 315         .byte   0x02
 316         .byte   0
 317         .word   0
 318
 319 .LmdbS4:
 320         # mdb
 321         .word   .LmtoS4-.LmdbS4
 322         .word   1
 323         .long   0xd4c4c240
 324         .long   1
 325
 326         # go
 327 .LgoS4:
 328         .word   .LmtoS4-.LgoS4
 329         .word   1
 330         .long   0
 331         .byte   0,0,0,0,0,0,0,0
 332         .byte   0,0,0
 333         .byte   0
 334         .byte   0,0,0,0,0,0,0
 335         .byte   0
 336         .word   0
 337         .byte   0,0,0,0,0,0,0,0,0,0
 338         .byte   0,0,0,0,0,0,0,0
 339         .byte   0,0,0,0,0,0,0,0
 340
 341 .LmtoS4:
 342         .word   .LmtoendS4-.LmtoS4
 343         .word   4
 344         .word   0x1000
 345         .byte   0
 346         .byte   0,0,0
 347 .LmtoendS4:
 348
 349         # Global constants
 350 .LsccbS0:
 351         .long   _sclp_work_area
 352 .Lascebc:
 353         .long   _ascebc
 354
 355 .section .data,"aw",@progbits
 356         .balign 4096
 357 _sclp_work_area:
 358         .fill   4096
 359 .previous