2 * arch/s390/kernel/cpcmd.c
5 * Copyright IBM Corp. 1999,2007
6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
7 * Christian Borntraeger (cborntra@de.ibm.com),
10 #define KMSG_COMPONENT "cpcmd"
11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/spinlock.h>
17 #include <linux/stddef.h>
18 #include <linux/string.h>
19 #include <asm/ebcdic.h>
20 #include <asm/cpcmd.h>
23 static DEFINE_SPINLOCK(cpcmd_lock);
24 static char cpcmd_buf[241];
26 static int diag8_noresponse(int cmdlen)
28 register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
29 register unsigned long reg3 asm ("3") = cmdlen;
34 #else /* CONFIG_64BIT */
38 #endif /* CONFIG_64BIT */
39 : "+d" (reg3) : "d" (reg2) : "cc");
43 static int diag8_response(int cmdlen, char *response, int *rlen)
45 register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
46 register unsigned long reg3 asm ("3") = (addr_t) response;
47 register unsigned long reg4 asm ("4") = cmdlen | 0x40000000L;
48 register unsigned long reg5 asm ("5") = *rlen;
55 #else /* CONFIG_64BIT */
61 #endif /* CONFIG_64BIT */
63 : "+d" (reg4), "+d" (reg5)
64 : "d" (reg2), "d" (reg3), "d" (*rlen) : "cc");
70 * __cpcmd has some restrictions over cpcmd
71 * - the response buffer must reside below 2GB (if any)
72 * - __cpcmd is unlocked and therefore not SMP-safe
74 int __cpcmd(const char *cmd, char *response, int rlen, int *response_code)
82 memcpy(cpcmd_buf, cmd, cmdlen);
83 ASCEBC(cpcmd_buf, cmdlen);
86 memset(response, 0, rlen);
88 rc = diag8_response(cmdlen, response, &rlen);
89 EBCASC(response, response_len);
91 rc = diag8_noresponse(cmdlen);
97 EXPORT_SYMBOL(__cpcmd);
99 int cpcmd(const char *cmd, char *response, int rlen, int *response_code)
105 if ((virt_to_phys(response) != (unsigned long) response) ||
106 (((unsigned long)response + rlen) >> 31)) {
107 lowbuf = kmalloc(rlen, GFP_KERNEL | GFP_DMA);
109 pr_warning("The cpcmd kernel function failed to "
110 "allocate a response buffer\n");
113 spin_lock_irqsave(&cpcmd_lock, flags);
114 len = __cpcmd(cmd, lowbuf, rlen, response_code);
115 spin_unlock_irqrestore(&cpcmd_lock, flags);
116 memcpy(response, lowbuf, rlen);
119 spin_lock_irqsave(&cpcmd_lock, flags);
120 len = __cpcmd(cmd, response, rlen, response_code);
121 spin_unlock_irqrestore(&cpcmd_lock, flags);
125 EXPORT_SYMBOL(cpcmd);