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   1 /*
   2  *  arch/s390/kernel/cpcmd.c
   3  *
   4  *  S390 version
   5  *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
   6  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
   7  *               Christian Borntraeger (cborntra@de.ibm.com),
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/slab.h>
  13 #include <linux/spinlock.h>
  14 #include <linux/stddef.h>
  15 #include <linux/string.h>
  16 #include <asm/ebcdic.h>
  17 #include <asm/cpcmd.h>
  18 #include <asm/system.h>
  19
  20 static DEFINE_SPINLOCK(cpcmd_lock);
  21 static char cpcmd_buf[240];
  22
  23 /*
  24  * the caller of __cpcmd has to ensure that the response buffer is below 2 GB
  25  */
  26 void __cpcmd(char *cmd, char *response, int rlen)
  27 {
  28         const int mask = 0x40000000L;
  29         unsigned long flags;
  30         int cmdlen;
  31
  32         spin_lock_irqsave(&cpcmd_lock, flags);
  33         cmdlen = strlen(cmd);
  34         BUG_ON(cmdlen > 240);
  35         strcpy(cpcmd_buf, cmd);
  36         ASCEBC(cpcmd_buf, cmdlen);
  37
  38         if (response != NULL && rlen > 0) {
  39                 memset(response, 0, rlen);
  40 #ifndef CONFIG_ARCH_S390X
  41                 asm volatile ("LRA   2,0(%0)\n\t"
  42                               "LR    4,%1\n\t"
  43                               "O     4,%4\n\t"
  44                               "LRA   3,0(%2)\n\t"
  45                               "LR    5,%3\n\t"
  46                               ".long 0x83240008 # Diagnose X'08'\n\t"
  47                               : /* no output */
  48                               : "a" (cpcmd_buf), "d" (cmdlen),
  49                                 "a" (response), "d" (rlen), "m" (mask)
  50                               : "cc", "2", "3", "4", "5" );
  51 #else /* CONFIG_ARCH_S390X */
  52                 asm volatile ("   lrag  2,0(%0)\n"
  53                               "   lgr   4,%1\n"
  54                               "   o     4,%4\n"
  55                               "   lrag  3,0(%2)\n"
  56                               "   lgr   5,%3\n"
  57                               "   sam31\n"
  58                               "   .long 0x83240008 # Diagnose X'08'\n"
  59                               "   sam64"
  60                               : /* no output */
  61                               : "a" (cpcmd_buf), "d" (cmdlen),
  62                                 "a" (response), "d" (rlen), "m" (mask)
  63                               : "cc", "2", "3", "4", "5" );
  64 #endif /* CONFIG_ARCH_S390X */
  65                 EBCASC(response, rlen);
  66         } else {
  67 #ifndef CONFIG_ARCH_S390X
  68                 asm volatile ("LRA   2,0(%0)\n\t"
  69                               "LR    3,%1\n\t"
  70                               ".long 0x83230008 # Diagnose X'08'\n\t"
  71                               : /* no output */
  72                               : "a" (cpcmd_buf), "d" (cmdlen)
  73                               : "2", "3"  );
  74 #else /* CONFIG_ARCH_S390X */
  75                 asm volatile ("   lrag  2,0(%0)\n"
  76                               "   lgr   3,%1\n"
  77                               "   sam31\n"
  78                               "   .long 0x83230008 # Diagnose X'08'\n"
  79                               "   sam64"
  80                               : /* no output */
  81                               : "a" (cpcmd_buf), "d" (cmdlen)
  82                               : "2", "3"  );
  83 #endif /* CONFIG_ARCH_S390X */
  84         }
  85         spin_unlock_irqrestore(&cpcmd_lock, flags);
  86 }
  87
  88 EXPORT_SYMBOL(__cpcmd);
  89
  90 #ifdef CONFIG_ARCH_S390X
  91 void cpcmd(char *cmd, char *response, int rlen)
  92 {
  93         char *lowbuf;
  94         if ((rlen == 0) || (response == NULL)
  95             || !((unsigned long)response >> 31))
  96                 __cpcmd(cmd, response, rlen);
  97         else {
  98                 lowbuf = kmalloc(rlen, GFP_KERNEL | GFP_DMA);
  99                 if (!lowbuf) {
 100                         printk(KERN_WARNING
 101                                 "cpcmd: could not allocate response buffer\n");
 102                         return;
 103                 }
 104                 __cpcmd(cmd, lowbuf, rlen);
 105                 memcpy(response, lowbuf, rlen);
 106                 kfree(lowbuf);
 107         }
 108 }
 109
 110 EXPORT_SYMBOL(cpcmd);
 111 #endif          /* CONFIG_ARCH_S390X */