Merge branch 'for-linus-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-3.10.git] / arch / s390 / kernel / cpcmd.c
index 44df8dc..d7b0c4d 100644 (file)
@@ -1,12 +1,13 @@
 /*
- *  arch/s390/kernel/cpcmd.c
- *
  *  S390 version
- *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Copyright IBM Corp. 1999, 2007
  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
  *               Christian Borntraeger (cborntra@de.ibm.com),
  */
 
+#define KMSG_COMPONENT "cpcmd"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <asm/ebcdic.h>
 #include <asm/cpcmd.h>
-#include <asm/system.h>
+#include <asm/io.h>
 
 static DEFINE_SPINLOCK(cpcmd_lock);
-static char cpcmd_buf[240];
+static char cpcmd_buf[241];
+
+static int diag8_noresponse(int cmdlen)
+{
+       register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
+       register unsigned long reg3 asm ("3") = cmdlen;
+
+       asm volatile(
+#ifndef CONFIG_64BIT
+               "       diag    %1,%0,0x8\n"
+#else /* CONFIG_64BIT */
+               "       sam31\n"
+               "       diag    %1,%0,0x8\n"
+               "       sam64\n"
+#endif /* CONFIG_64BIT */
+               : "+d" (reg3) : "d" (reg2) : "cc");
+       return reg3;
+}
+
+static int diag8_response(int cmdlen, char *response, int *rlen)
+{
+       register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
+       register unsigned long reg3 asm ("3") = (addr_t) response;
+       register unsigned long reg4 asm ("4") = cmdlen | 0x40000000L;
+       register unsigned long reg5 asm ("5") = *rlen;
+
+       asm volatile(
+#ifndef CONFIG_64BIT
+               "       diag    %2,%0,0x8\n"
+               "       brc     8,1f\n"
+               "       ar      %1,%4\n"
+#else /* CONFIG_64BIT */
+               "       sam31\n"
+               "       diag    %2,%0,0x8\n"
+               "       sam64\n"
+               "       brc     8,1f\n"
+               "       agr     %1,%4\n"
+#endif /* CONFIG_64BIT */
+               "1:\n"
+               : "+d" (reg4), "+d" (reg5)
+               : "d" (reg2), "d" (reg3), "d" (*rlen) : "cc");
+       *rlen = reg5;
+       return reg4;
+}
 
 /*
- * the caller of __cpcmd has to ensure that the response buffer is below 2 GB
+ * __cpcmd has some restrictions over cpcmd
+ *  - the response buffer must reside below 2GB (if any)
+ *  - __cpcmd is unlocked and therefore not SMP-safe
  */
-void __cpcmd(char *cmd, char *response, int rlen)
+int  __cpcmd(const char *cmd, char *response, int rlen, int *response_code)
 {
-       const int mask = 0x40000000L;
-       unsigned long flags;
        int cmdlen;
+       int rc;
+       int response_len;
 
-       spin_lock_irqsave(&cpcmd_lock, flags);
        cmdlen = strlen(cmd);
        BUG_ON(cmdlen > 240);
-       strcpy(cpcmd_buf, cmd);
+       memcpy(cpcmd_buf, cmd, cmdlen);
        ASCEBC(cpcmd_buf, cmdlen);
 
-       if (response != NULL && rlen > 0) {
+       if (response) {
                memset(response, 0, rlen);
-#ifndef CONFIG_ARCH_S390X
-               asm volatile ("LRA   2,0(%0)\n\t"
-                              "LR    4,%1\n\t"
-                              "O     4,%4\n\t"
-                              "LRA   3,0(%2)\n\t"
-                              "LR    5,%3\n\t"
-                              ".long 0x83240008 # Diagnose X'08'\n\t"
-                              : /* no output */
-                              : "a" (cpcmd_buf), "d" (cmdlen),
-                                "a" (response), "d" (rlen), "m" (mask)
-                              : "cc", "2", "3", "4", "5" );
-#else /* CONFIG_ARCH_S390X */
-                asm volatile ("   lrag  2,0(%0)\n"
-                              "   lgr   4,%1\n"
-                              "   o     4,%4\n"
-                              "   lrag  3,0(%2)\n"
-                              "   lgr   5,%3\n"
-                              "   sam31\n"
-                              "   .long 0x83240008 # Diagnose X'08'\n"
-                              "   sam64"
-                              : /* no output */
-                              : "a" (cpcmd_buf), "d" (cmdlen),
-                                "a" (response), "d" (rlen), "m" (mask)
-                              : "cc", "2", "3", "4", "5" );
-#endif /* CONFIG_ARCH_S390X */
-                EBCASC(response, rlen);
+               response_len = rlen;
+               rc = diag8_response(cmdlen, response, &rlen);
+               EBCASC(response, response_len);
         } else {
-#ifndef CONFIG_ARCH_S390X
-                asm volatile ("LRA   2,0(%0)\n\t"
-                              "LR    3,%1\n\t"
-                              ".long 0x83230008 # Diagnose X'08'\n\t"
-                              : /* no output */
-                              : "a" (cpcmd_buf), "d" (cmdlen)
-                              : "2", "3"  );
-#else /* CONFIG_ARCH_S390X */
-                asm volatile ("   lrag  2,0(%0)\n"
-                              "   lgr   3,%1\n"
-                              "   sam31\n"
-                              "   .long 0x83230008 # Diagnose X'08'\n"
-                              "   sam64"
-                              : /* no output */
-                              : "a" (cpcmd_buf), "d" (cmdlen)
-                              : "2", "3"  );
-#endif /* CONFIG_ARCH_S390X */
+               rc = diag8_noresponse(cmdlen);
         }
-       spin_unlock_irqrestore(&cpcmd_lock, flags);
+       if (response_code)
+               *response_code = rc;
+       return rlen;
 }
-
 EXPORT_SYMBOL(__cpcmd);
 
-#ifdef CONFIG_ARCH_S390X
-void cpcmd(char *cmd, char *response, int rlen)
+int cpcmd(const char *cmd, char *response, int rlen, int *response_code)
 {
        char *lowbuf;
-       if ((rlen == 0) || (response == NULL)
-           || !((unsigned long)response >> 31))
-               __cpcmd(cmd, response, rlen);
-       else {
+       int len;
+       unsigned long flags;
+
+       if ((virt_to_phys(response) != (unsigned long) response) ||
+                       (((unsigned long)response + rlen) >> 31)) {
                lowbuf = kmalloc(rlen, GFP_KERNEL | GFP_DMA);
                if (!lowbuf) {
-                       printk(KERN_WARNING
-                               "cpcmd: could not allocate response buffer\n");
-                       return;
+                       pr_warning("The cpcmd kernel function failed to "
+                                  "allocate a response buffer\n");
+                       return -ENOMEM;
                }
-               __cpcmd(cmd, lowbuf, rlen);
+               spin_lock_irqsave(&cpcmd_lock, flags);
+               len = __cpcmd(cmd, lowbuf, rlen, response_code);
+               spin_unlock_irqrestore(&cpcmd_lock, flags);
                memcpy(response, lowbuf, rlen);
                kfree(lowbuf);
+       } else {
+               spin_lock_irqsave(&cpcmd_lock, flags);
+               len = __cpcmd(cmd, response, rlen, response_code);
+               spin_unlock_irqrestore(&cpcmd_lock, flags);
        }
+       return len;
 }
-
 EXPORT_SYMBOL(cpcmd);
-#endif         /* CONFIG_ARCH_S390X */