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 2006214..d7b0c4d 100644 (file)
@@ -1,12 +1,13 @@
 /*
- *  arch/s390/kernel/cpcmd.c
- *
  *  S390 version
- *    Copyright (C) 1999,2005 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[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
  */
 int  __cpcmd(const char *cmd, char *response, int rlen, int *response_code)
 {
-       const int mask = 0x40000000L;
-       unsigned long flags;
-       int return_code;
-       int return_len;
        int cmdlen;
+       int rc;
+       int response_len;
 
-       spin_lock_irqsave(&cpcmd_lock, flags);
        cmdlen = strlen(cmd);
        BUG_ON(cmdlen > 240);
        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(%2)\n"
-                               "lr     4,%3\n"
-                               "o      4,%6\n"
-                               "lra    3,0(%4)\n"
-                               "lr     5,%5\n"
-                               "diag   2,4,0x8\n"
-                               "brc    8, .Litfits\n"
-                               "ar     5, %5\n"
-                               ".Litfits: \n"
-                               "lr     %0,4\n"
-                               "lr     %1,5\n"
-                               : "=d" (return_code), "=d" (return_len)
-                               : "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(%2)\n"
-                               "lgr    4,%3\n"
-                               "o      4,%6\n"
-                               "lrag   3,0(%4)\n"
-                               "lgr    5,%5\n"
-                               "sam31\n"
-                               "diag   2,4,0x8\n"
-                               "sam64\n"
-                               "brc    8, .Litfits\n"
-                               "agr    5, %5\n"
-                               ".Litfits: \n"
-                               "lgr    %0,4\n"
-                               "lgr    %1,5\n"
-                               : "=d" (return_code), "=d" (return_len)
-                               : "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 {
-               return_len = 0;
-#ifndef CONFIG_ARCH_S390X
-                asm volatile ( "lra    2,0(%1)\n"
-                               "lr     3,%2\n"
-                               "diag   2,3,0x8\n"
-                               "lr     %0,3\n"
-                               : "=d" (return_code)
-                               : "a" (cpcmd_buf), "d" (cmdlen)
-                               : "2", "3"  );
-#else /* CONFIG_ARCH_S390X */
-                asm volatile ( "lrag   2,0(%1)\n"
-                               "lgr    3,%2\n"
-                               "sam31\n"
-                               "diag   2,3,0x8\n"
-                               "sam64\n"
-                               "lgr    %0,3\n"
-                               : "=d" (return_code)
-                               : "a" (cpcmd_buf), "d" (cmdlen)
-                               : "2", "3" );
-#endif /* CONFIG_ARCH_S390X */
+               rc = diag8_noresponse(cmdlen);
         }
-       spin_unlock_irqrestore(&cpcmd_lock, flags);
-       if (response_code != NULL)
-               *response_code = return_code;
-       return return_len;
+       if (response_code)
+               *response_code = rc;
+       return rlen;
 }
-
 EXPORT_SYMBOL(__cpcmd);
 
-#ifdef CONFIG_ARCH_S390X
 int cpcmd(const char *cmd, char *response, int rlen, int *response_code)
 {
        char *lowbuf;
        int len;
+       unsigned long flags;
 
-       if ((rlen == 0) || (response == NULL)
-           || !((unsigned long)response >> 31))
-               len = __cpcmd(cmd, response, rlen, response_code);
-       else {
+       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");
+                       pr_warning("The cpcmd kernel function failed to "
+                                  "allocate a response buffer\n");
                        return -ENOMEM;
                }
+               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 */