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   1 /* $Id: p1275.c,v 1.22 2001/10/18 09:40:00 davem Exp $
   2  * p1275.c: Sun IEEE 1275 PROM low level interface routines
   3  *
   4  * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/init.h>
   9 #include <linux/sched.h>
  10 #include <linux/smp.h>
  11 #include <linux/string.h>
  12 #include <linux/spinlock.h>
  13
  14 #include <asm/openprom.h>
  15 #include <asm/oplib.h>
  16 #include <asm/system.h>
  17 #include <asm/spitfire.h>
  18 #include <asm/pstate.h>
  19
  20 struct {
  21         long prom_callback;                     /* 0x00 */
  22         void (*prom_cif_handler)(long *);       /* 0x08 */
  23         unsigned long prom_cif_stack;           /* 0x10 */
  24         unsigned long prom_args [23];           /* 0x18 */
  25         char prom_buffer [3000];
  26 } p1275buf;
  27
  28 extern void prom_world(int);
  29
  30 extern void prom_cif_interface(void);
  31 extern void prom_cif_callback(void);
  32
  33 static inline unsigned long spitfire_get_primary_context(void)
  34 {
  35         unsigned long ctx;
  36
  37         __asm__ __volatile__("ldxa      [%1] %2, %0"
  38                              : "=r" (ctx)
  39                              : "r" (PRIMARY_CONTEXT), "i" (ASI_DMMU));
  40         return ctx;
  41 }
  42
  43 /*
  44  * This provides SMP safety on the p1275buf. prom_callback() drops this lock
  45  * to allow recursuve acquisition.
  46  */
  47 DEFINE_SPINLOCK(prom_entry_lock);
  48
  49 long p1275_cmd (char *service, long fmt, ...)
  50 {
  51         char *p, *q;
  52         unsigned long flags;
  53         int nargs, nrets, i;
  54         va_list list;
  55         long attrs, x;
  56
  57         p = p1275buf.prom_buffer;
  58         BUG_ON((spitfire_get_primary_context() & CTX_NR_MASK) != 0);
  59
  60         spin_lock_irqsave(&prom_entry_lock, flags);
  61
  62         p1275buf.prom_args[0] = (unsigned long)p;               /* service */
  63         strcpy (p, service);
  64         p = (char *)(((long)(strchr (p, 0) + 8)) & ~7);
  65         p1275buf.prom_args[1] = nargs = (fmt & 0x0f);           /* nargs */
  66         p1275buf.prom_args[2] = nrets = ((fmt & 0xf0) >> 4);    /* nrets */
  67         attrs = fmt >> 8;
  68         va_start(list, fmt);
  69         for (i = 0; i < nargs; i++, attrs >>= 3) {
  70                 switch (attrs & 0x7) {
  71                 case P1275_ARG_NUMBER:
  72                         p1275buf.prom_args[i + 3] =
  73                                                 (unsigned)va_arg(list, long);
  74                         break;
  75                 case P1275_ARG_IN_64B:
  76                         p1275buf.prom_args[i + 3] =
  77                                 va_arg(list, unsigned long);
  78                         break;
  79                 case P1275_ARG_IN_STRING:
  80                         strcpy (p, va_arg(list, char *));
  81                         p1275buf.prom_args[i + 3] = (unsigned long)p;
  82                         p = (char *)(((long)(strchr (p, 0) + 8)) & ~7);
  83                         break;
  84                 case P1275_ARG_OUT_BUF:
  85                         (void) va_arg(list, char *);
  86                         p1275buf.prom_args[i + 3] = (unsigned long)p;
  87                         x = va_arg(list, long);
  88                         i++; attrs >>= 3;
  89                         p = (char *)(((long)(p + (int)x + 7)) & ~7);
  90                         p1275buf.prom_args[i + 3] = x;
  91                         break;
  92                 case P1275_ARG_IN_BUF:
  93                         q = va_arg(list, char *);
  94                         p1275buf.prom_args[i + 3] = (unsigned long)p;
  95                         x = va_arg(list, long);
  96                         i++; attrs >>= 3;
  97                         memcpy (p, q, (int)x);
  98                         p = (char *)(((long)(p + (int)x + 7)) & ~7);
  99                         p1275buf.prom_args[i + 3] = x;
 100                         break;
 101                 case P1275_ARG_OUT_32B:
 102                         (void) va_arg(list, char *);
 103                         p1275buf.prom_args[i + 3] = (unsigned long)p;
 104                         p += 32;
 105                         break;
 106                 case P1275_ARG_IN_FUNCTION:
 107                         p1275buf.prom_args[i + 3] =
 108                                         (unsigned long)prom_cif_callback;
 109                         p1275buf.prom_callback = va_arg(list, long);
 110                         break;
 111                 }
 112         }
 113         va_end(list);
 114
 115         prom_world(1);
 116         prom_cif_interface();
 117         prom_world(0);
 118
 119         attrs = fmt >> 8;
 120         va_start(list, fmt);
 121         for (i = 0; i < nargs; i++, attrs >>= 3) {
 122                 switch (attrs & 0x7) {
 123                 case P1275_ARG_NUMBER:
 124                         (void) va_arg(list, long);
 125                         break;
 126                 case P1275_ARG_IN_STRING:
 127                         (void) va_arg(list, char *);
 128                         break;
 129                 case P1275_ARG_IN_FUNCTION:
 130                         (void) va_arg(list, long);
 131                         break;
 132                 case P1275_ARG_IN_BUF:
 133                         (void) va_arg(list, char *);
 134                         (void) va_arg(list, long);
 135                         i++; attrs >>= 3;
 136                         break;
 137                 case P1275_ARG_OUT_BUF:
 138                         p = va_arg(list, char *);
 139                         x = va_arg(list, long);
 140                         memcpy (p, (char *)(p1275buf.prom_args[i + 3]), (int)x);
 141                         i++; attrs >>= 3;
 142                         break;
 143                 case P1275_ARG_OUT_32B:
 144                         p = va_arg(list, char *);
 145                         memcpy (p, (char *)(p1275buf.prom_args[i + 3]), 32);
 146                         break;
 147                 }
 148         }
 149         va_end(list);
 150         x = p1275buf.prom_args [nargs + 3];
 151
 152         spin_unlock_irqrestore(&prom_entry_lock, flags);
 153
 154         return x;
 155 }
 156
 157 void prom_cif_init(void *cif_handler, void *cif_stack)
 158 {
 159         p1275buf.prom_cif_handler = (void (*)(long *))cif_handler;
 160         p1275buf.prom_cif_stack = (unsigned long)cif_stack;
 161 }