* 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 <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, 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" );
-#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, 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" );
-#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 */
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