arch/parisc/kernel/hpmc.S

   1 /*
   2  * HPMC (High Priority Machine Check) handler.
   3  *
   4  * Copyright (C) 1999 Philipp Rumpf <prumpf@tux.org>
   5  * Copyright (C) 1999 Hewlett-Packard (Frank Rowand)
   6  * Copyright (C) 2000 Hewlett-Packard (John Marvin)
   7  *
   8  *    This program is free software; you can redistribute it and/or modify
   9  *    it under the terms of the GNU General Public License as published by
  10  *    the Free Software Foundation; either version 2, or (at your option)
  11  *    any later version.
  12  *
  13  *    This program is distributed in the hope that it will be useful,
  14  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *    GNU General Public License for more details.
  17  *
  18  *    You should have received a copy of the GNU General Public License
  19  *    along with this program; if not, write to the Free Software
  20  *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23
  24 /*
  25  * This HPMC handler retrieves the HPMC pim data, resets IO and
  26  * returns to the default trap handler with code set to 1 (HPMC).
  27  * The default trap handler calls handle interruption, which
  28  * does a stack and register dump. This at least allows kernel
  29  * developers to get back to C code in virtual mode, where they
  30  * have the option to examine and print values from memory that
  31  * would help in debugging an HPMC caused by a software bug.
  32  *
  33  * There is more to do here:
  34  *
  35  *      1) On MP systems we need to synchronize processors
  36  *         before calling pdc/iodc.
  37  *      2) We should be checking the system state and not
  38  *         returning to the fault handler if things are really
  39  *         bad.
  40  *
  41  */
  42
  43         .level          1.1
  44         .data
  45
  46 #include <asm/assembly.h>
  47 #include <asm/pdc.h>
  48
  49         /*
  50          * stack for os_hpmc, the HPMC handler.
  51          * buffer for IODC procedures (for the HPMC handler).
  52          *
  53          * IODC requires 7K byte stack.  That leaves 1K byte for os_hpmc.
  54          */
  55
  56         .align 4096
  57 hpmc_stack:
  58         .block 16384
  59
  60 #define HPMC_IODC_BUF_SIZE 0x8000
  61
  62         .align 4096
  63 hpmc_iodc_buf:
  64         .block HPMC_IODC_BUF_SIZE
  65
  66         .align 8
  67 hpmc_raddr:
  68         .block 128
  69
  70 #define HPMC_PIM_DATA_SIZE 896 /* Enough to hold all architected 2.0 state */
  71
  72         .export hpmc_pim_data, data
  73         .align 8
  74 hpmc_pim_data:
  75         .block HPMC_PIM_DATA_SIZE
  76
  77         .text
  78
  79         .export os_hpmc, code
  80         .import intr_save, code
  81
  82 os_hpmc:
  83
  84         /*
  85          * registers modified:
  86          *
  87          *   Using callee saves registers without saving them.  The
  88          *   original values are in the pim dump if we need them.
  89          *
  90          *   r2   (rp)  return pointer
  91          *   r3   address of PDCE_PROC
  92          *   r4   scratch
  93          *   r5   scratch
  94          *   r23  (arg3) procedure arg
  95          *   r24  (arg2) procedure arg
  96          *   r25  (arg1) procedure arg
  97          *   r26  (arg0) procedure arg
  98          *   r30  (sp)   stack pointer
  99          *
 100          * registers read:
 101          *
 102          *   r26  contains address of PDCE_PROC on entry
 103          *   r28  (ret0) return value from procedure
 104          */
 105
 106         copy    arg0, %r3       /* save address of PDCE_PROC */
 107
 108         /*
 109          *  disable nested HPMCs
 110          *
 111          * Increment os_hpmc checksum to invalidate it.
 112          * Do this before turning the PSW M bit off.
 113          */
 114
 115         mfctl   %cr14, %r4
 116         ldw     52(%r4),%r5
 117         addi    1,%r5,%r5
 118         stw     %r5,52(%r4)
 119
 120         /* MP_FIXME: synchronize all processors. */
 121
 122         /* Setup stack pointer. */
 123
 124         load32  PA(hpmc_stack),sp
 125
 126         ldo     128(sp),sp /* leave room for arguments */
 127
 128         /*
 129          * Most PDC routines require that the M bit be off.
 130          * So turn on the Q bit and turn off the M bit.
 131          */
 132
 133         ldo     8(%r0),%r4                       /* PSW Q on, PSW M off */
 134         mtctl   %r4,ipsw
 135         mtctl   %r0,pcsq
 136         mtctl   %r0,pcsq
 137         load32  PA(os_hpmc_1),%r4
 138         mtctl   %r4,pcoq
 139         ldo     4(%r4),%r4
 140         mtctl   %r4,pcoq
 141         rfi
 142         nop
 143
 144 os_hpmc_1:
 145
 146         /* Call PDC_PIM to get HPMC pim info */
 147
 148         /*
 149          * Note that on some newer boxes, PDC_PIM must be called
 150          * before PDC_IO if you want IO to be reset. PDC_PIM sets
 151          * a flag that PDC_IO examines.
 152          */
 153
 154         ldo     PDC_PIM(%r0), arg0
 155         ldo     PDC_PIM_HPMC(%r0),arg1          /* Transfer HPMC data */
 156         load32  PA(hpmc_raddr),arg2
 157         load32  PA(hpmc_pim_data),arg3
 158         load32  HPMC_PIM_DATA_SIZE,%r4
 159         stw     %r4,-52(sp)
 160
 161         ldil    L%PA(os_hpmc_2), rp
 162         bv      (r3)                            /* call pdce_proc */
 163         ldo     R%PA(os_hpmc_2)(rp), rp
 164
 165 os_hpmc_2:
 166         comib,<>  0,ret0, os_hpmc_fail
 167
 168         /* Reset IO by calling the hversion dependent PDC_IO routine */
 169
 170         ldo     PDC_IO(%r0),arg0
 171         ldo     0(%r0),arg1                     /* log IO errors */
 172         ldo     0(%r0),arg2                     /* reserved */
 173         ldo     0(%r0),arg3                     /* reserved */
 174         stw     %r0,-52(sp)                     /* reserved */
 175
 176         ldil    L%PA(os_hpmc_3),rp
 177         bv      (%r3)                           /* call pdce_proc */
 178         ldo     R%PA(os_hpmc_3)(rp),rp
 179
 180 os_hpmc_3:
 181
 182         /* FIXME? Check for errors from PDC_IO (-1 might be OK) */
 183
 184         /*
 185          * Initialize the IODC console device (HPA,SPA, path etc.
 186          * are stored on page 0.
 187          */
 188
 189         /*
 190          * Load IODC into hpmc_iodc_buf by calling PDC_IODC.
 191          * Note that PDC_IODC handles flushing the appropriate
 192          * data and instruction cache lines.
 193          */
 194
 195         ldo     PDC_IODC(%r0),arg0
 196         ldo     PDC_IODC_READ(%r0),arg1
 197         load32  PA(hpmc_raddr),arg2
 198         ldw     BOOT_CONSOLE_HPA_OFFSET(%r0),arg3 /* console hpa */
 199         ldo     PDC_IODC_RI_INIT(%r0),%r4
 200         stw     %r4,-52(sp)
 201         load32  PA(hpmc_iodc_buf),%r4
 202         stw     %r4,-56(sp)
 203         load32  HPMC_IODC_BUF_SIZE,%r4
 204         stw     %r4,-60(sp)
 205
 206         ldil    L%PA(os_hpmc_4),rp
 207         bv      (%r3)                            /* call pdce_proc */
 208         ldo     R%PA(os_hpmc_4)(rp),rp
 209
 210 os_hpmc_4:
 211         comib,<>  0,ret0,os_hpmc_fail
 212
 213         /* Call the entry init (just loaded by PDC_IODC) */
 214
 215         ldw     BOOT_CONSOLE_HPA_OFFSET(%r0),arg0  /* console hpa */
 216         ldo     ENTRY_INIT_MOD_DEV(%r0), arg1
 217         ldw     BOOT_CONSOLE_SPA_OFFSET(%r0),arg2  /* console spa */
 218         depi    0,31,11,arg2                       /* clear bits 21-31    */
 219         ldo     BOOT_CONSOLE_PATH_OFFSET(%r0),arg3 /* console path */
 220         load32  PA(hpmc_raddr),%r4
 221         stw     %r4, -52(sp)
 222         stw     %r0, -56(sp)                    /* HV                  */
 223         stw     %r0, -60(sp)                    /* HV                  */
 224         stw     %r0, -64(sp)                    /* HV                  */
 225         stw     %r0, -68(sp)                    /* lang, must be zero  */
 226
 227         load32  PA(hpmc_iodc_buf),%r5
 228         ldil    L%PA(os_hpmc_5),rp
 229         bv      (%r5)
 230         ldo     R%PA(os_hpmc_5)(rp),rp
 231
 232 os_hpmc_5:
 233         comib,<>  0,ret0,os_hpmc_fail
 234
 235         /* Prepare to call intr_save */
 236
 237         /*
 238          * Load kernel page directory (load into user also, since
 239          * we don't intend to ever return to user land anyway)
 240          */
 241
 242         load32          PA(swapper_pg_dir),%r4
 243         mtctl           %r4,%cr24       /* Initialize kernel root pointer */
 244         mtctl           %r4,%cr25       /* Initialize user root pointer */
 245
 246         /* Clear sr4-sr7 */
 247
 248         mtsp    %r0, %sr4
 249         mtsp    %r0, %sr5
 250         mtsp    %r0, %sr6
 251         mtsp    %r0, %sr7
 252
 253         tovirt_r1 %r30      /* make sp virtual */
 254
 255         rsm 8,%r0           /* Clear Q bit */
 256         ldi     1,%r8       /* Set trap code to "1" for HPMC */
 257         load32  PA(intr_save),%r1
 258         be      0(%sr7,%r1)
 259         nop
 260
 261 os_hpmc_fail:
 262
 263         /*
 264          * Reset the system
 265          *
 266          * Some systems may lockup from a broadcast reset, so try the
 267          * hversion PDC_BROADCAST_RESET() first.
 268          * MP_FIXME: reset all processors if more than one central bus.
 269          */
 270
 271         /* PDC_BROADCAST_RESET() */
 272
 273         ldo     PDC_BROADCAST_RESET(%r0),arg0
 274         ldo     0(%r0),arg1                     /* do reset */
 275
 276         ldil    L%PA(os_hpmc_6),rp
 277         bv      (%r3)                           /* call pdce_proc */
 278         ldo     R%PA(os_hpmc_6)(rp),rp
 279
 280 os_hpmc_6:
 281
 282         /*
 283          * possible return values:
 284          *  -1  non-existent procedure
 285          *  -2  non-existent option
 286          *  -16 unaligned stack
 287          *
 288          * If call returned, do a broadcast reset.
 289          */
 290
 291         ldil    L%0xfffc0000,%r4        /* IO_BROADCAST */
 292         ldo     5(%r0),%r5
 293         stw     %r5,48(%r4)             /*  CMD_RESET to IO_COMMAND offset */
 294
 295         b .
 296         nop
 297
 298         /* this label used to compute os_hpmc checksum */
 299
 300         .export os_hpmc_end, code
 301
 302 os_hpmc_end:
 303
 304         nop