arch/powerpc/xmon/spr_access.S

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #include <asm/ppc_asm.h>
   3
   4 /* unsigned long xmon_mfspr(sprn, default_value) */
   5 _GLOBAL(xmon_mfspr)
   6         PPC_LL  r5, .Lmfspr_table@got(r2)
   7         b       xmon_mxspr
   8
   9 /* void xmon_mtspr(sprn, new_value) */
  10 _GLOBAL(xmon_mtspr)
  11         PPC_LL  r5, .Lmtspr_table@got(r2)
  12         b       xmon_mxspr
  13
  14 /*
  15  * r3 = sprn
  16  * r4 = default or new value
  17  * r5 = table base
  18  */
  19 xmon_mxspr:
  20         /*
  21          * To index into the table of mxsprs we need:
  22          *  i = (sprn & 0x3ff) * 8
  23          * or using rwlinm:
  24          *  i = (sprn << 3) & (0x3ff << 3)
  25          */
  26         rlwinm  r3, r3, 3, 0x3ff << 3
  27         add     r5, r5, r3
  28         mtctr   r5
  29         mr      r3, r4 /* put default_value in r3 for mfspr */
  30         bctr
  31
  32 .Lmfspr_table:
  33         spr = 0
  34         .rept   1024
  35         mfspr   r3, spr
  36         blr
  37         spr = spr + 1
  38         .endr
  39
  40 .Lmtspr_table:
  41         spr = 0
  42         .rept   1024
  43         mtspr   spr, r4
  44         blr
  45         spr = spr + 1
  46         .endr