X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fs390%2Fkernel%2Fcpcmd.c;h=a5972f1541fea7525afc6c12f868cb7aa5d0efbd;hb=refs%2Fheads%2Fvserver;hp=4ef44e536b2c6495a7ff5e05c4f7e5d444d40042;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git

diff --git a/arch/s390/kernel/cpcmd.c b/arch/s390/kernel/cpcmd.c
index 4ef44e536..a5972f154 100644
--- a/arch/s390/kernel/cpcmd.c
+++ b/arch/s390/kernel/cpcmd.c
@@ -21,83 +21,60 @@ static DEFINE_SPINLOCK(cpcmd_lock);
 static char cpcmd_buf[241];
 
 /*
- * 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;
+	unsigned cmdlen;
+	int return_code, return_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) {
+		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;
+
 		memset(response, 0, rlen);
+		asm volatile(
 #ifndef CONFIG_64BIT
-		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, 1f\n"
-				"ar	5, %5\n"
-				"1: \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" );
+			"	diag	%2,%0,0x8\n"
+			"	brc	8,1f\n"
+			"	ar	%1,%4\n"
 #else /* CONFIG_64BIT */
-                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, 1f\n"
-				"agr	5, %5\n"
-				"1: \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" );
+			"	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");
+		return_code = (int) reg4;
+		return_len = (int) reg5;
                 EBCASC(response, rlen);
         } else {
+		register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
+		register unsigned long reg3 asm ("3") = cmdlen;
 		return_len = 0;
+		asm volatile(
 #ifndef CONFIG_64BIT
-                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"  );
+			"	diag	%1,%0,0x8\n"
 #else /* CONFIG_64BIT */
-                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" );
+			"	sam31\n"
+			"	diag	%1,%0,0x8\n"
+			"	sam64\n"
 #endif /* CONFIG_64BIT */
+			: "+d" (reg3) : "d" (reg2) : "cc");
+		return_code = (int) reg3;
         }
-	spin_unlock_irqrestore(&cpcmd_lock, flags);
 	if (response_code != NULL)
 		*response_code = return_code;
 	return return_len;
@@ -105,15 +82,18 @@ int  __cpcmd(const char *cmd, char *response, int rlen, int *response_code)
 
 EXPORT_SYMBOL(__cpcmd);
 
-#ifdef CONFIG_64BIT
 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))
+	    || !((unsigned long)response >> 31)) {
+		spin_lock_irqsave(&cpcmd_lock, flags);
 		len = __cpcmd(cmd, response, rlen, response_code);
+		spin_unlock_irqrestore(&cpcmd_lock, flags);
+	}
 	else {
 		lowbuf = kmalloc(rlen, GFP_KERNEL | GFP_DMA);
 		if (!lowbuf) {
@@ -121,7 +101,9 @@ int cpcmd(const char *cmd, char *response, int rlen, int *response_code)
 				"cpcmd: could not allocate 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);
 	}
@@ -129,4 +111,3 @@ int cpcmd(const char *cmd, char *response, int rlen, int *response_code)
 }
 
 EXPORT_SYMBOL(cpcmd);
-#endif		/* CONFIG_64BIT */