arch/sparc/kernel/mp.S

/* */
   1 /* $Id: mp.S,v 1.2 1995/11/25 00:58:11 davem Exp $
   2  * mp.S:  Multiprocessor low-level routines on the Sparc.
   3  *
   4  * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
   5  */
   6 
   7 #include <asm/cprefix.h>
   8 #include <asm/head.h>
   9 #include <asm/psr.h>
  10 #include <asm/asi.h>
  11 #include <asm/vaddrs.h>
  12 #include <asm/contregs.h>
  13 
  14 
  15         .text
  16         .align 4
  17 
  18 /* When we start up a cpu for the first time it enters this routine.
  19  * This initializes the chip from whatever state the prom left it
  20  * in and sets PIL in %psr to 15, no irqs.
  21  */
  22 
  23         .globl C_LABEL(sparc_cpu_startup)
  24 C_LABEL(sparc_cpu_startup):
  25         /* Set up a sane %psr -- PIL<0xf> S<0x1> PS<0x1> CWP<0x0> */
  26         set     (PSR_PIL | PSR_S | PSR_PS), %g1
  27         wr      %g1, 0x0, %psr          ! traps off though
  28         WRITE_PAUSE
  29 
  30         /* Our %wim is one behind CWP */
  31         wr      %g0, 0x2, %wim
  32 
  33         rd      %tbr, %g4
  34         or      %g0, 0x3, %g5
  35         sll     %g5, 20, %g5
  36         and     %g4, %g5, %g4           ! Mask cpu-id bits
  37 
  38         /* Give ourselves a stack. */
  39         set     PERCPU_VADDR, %g1
  40         add     %g1, %g4, %g1
  41         set     PERCPU_KSTACK_OFFSET, %g5
  42         add     %g1, %g5, %g1
  43         set     0x1000, %g5
  44         add     %g1, %g5, %g1           ! end of stack
  45         sub     %g1, (96+96+80), %g1    ! set up a frame
  46         andn    %g1, 0x7, %g1
  47         or      %g1, 0x0, %fp           ! bottom of frame
  48         add     %fp, (96+80), %sp       ! top of frame
  49 
  50         /* Set up per-cpu trap table pointer.  In actuality, the virtual
  51          * address for the trap table on every cpu points to the same
  52          * physical address, this virtual address is only used for cpu
  53          * identification purposes.
  54          */
  55 #if 0
  56 /*      set     PERCPU_VADDR, %g1 */
  57 /*      add     %g1, %g4, %g1 */
  58 /*      add     %g1, PERCPU_TBR_OFFSET, %g1 */
  59         set     C_LABEL(thiscpus_tbr), %g1
  60         ld      [%g1], %g1
  61         wr      %g1, 0x0, %tbr
  62         WRITE_PAUSE
  63 #else
  64         set     C_LABEL(trapbase), %g3
  65         wr      %g3, 0x0, %tbr
  66         WRITE_PAUSE
  67 #endif
  68 
  69         /* Turn on traps (PSR_ET). */
  70         rd      %psr, %g1
  71         wr      %g1, PSR_ET, %psr       ! traps on
  72 
  73 #if 0
  74 1:      nop
  75         b       1b
  76         nop
  77 #endif
  78 
  79         /* Call C-code to do the rest of the real work. */
  80         call    C_LABEL(sparc_cpu_init)
  81         nop
  82 
  83         /* Call cpu-idle routine so we can start it up later on. */
  84         call    C_LABEL(sparc_cpu_idle)
  85         nop
  86 
  87         /* Done... This cpu should me spinning in a test loop.
  88          * If execution gets here, something really bad happened.
  89          */
  90         call    C_LABEL(prom_halt)      ! Seems reasonable...
  91         nop
  92
/* */
root/arch/sparc/kernel/mp.S
