3 * Copyright IBM Corp. 1999, 2007
4 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
5 * Christian Borntraeger (cborntra@de.ibm.com),
8 #define KMSG_COMPONENT "cpcmd"
9 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
11 #include <linux/kernel.h>
12 #include <linux/export.h>
13 #include <linux/slab.h>
14 #include <linux/spinlock.h>
15 #include <linux/stddef.h>
16 #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;
33 : "+d" (reg3) : "d" (reg2) : "cc");
37 static int diag8_response(int cmdlen, char *response, int *rlen)
39 register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
40 register unsigned long reg3 asm ("3") = (addr_t) response;
41 register unsigned long reg4 asm ("4") = cmdlen | 0x40000000L;
42 register unsigned long reg5 asm ("5") = *rlen;
49 : "+d" (reg4), "+d" (reg5)
50 : "d" (reg2), "d" (reg3), "d" (*rlen) : "cc");
56 * __cpcmd has some restrictions over cpcmd
57 * - __cpcmd is unlocked and therefore not SMP-safe
59 int __cpcmd(const char *cmd, char *response, int rlen, int *response_code)
67 memcpy(cpcmd_buf, cmd, cmdlen);
68 ASCEBC(cpcmd_buf, cmdlen);
70 diag_stat_inc(DIAG_STAT_X008);
72 memset(response, 0, rlen);
74 rc = diag8_response(cmdlen, response, &rlen);
75 EBCASC(response, response_len);
77 rc = diag8_noresponse(cmdlen);
83 EXPORT_SYMBOL(__cpcmd);
85 int cpcmd(const char *cmd, char *response, int rlen, int *response_code)
91 if (is_vmalloc_or_module_addr(response)) {
92 lowbuf = kmalloc(rlen, GFP_KERNEL);
94 pr_warn("The cpcmd kernel function failed to allocate a response buffer\n");
97 spin_lock_irqsave(&cpcmd_lock, flags);
98 len = __cpcmd(cmd, lowbuf, rlen, response_code);
99 spin_unlock_irqrestore(&cpcmd_lock, flags);
100 memcpy(response, lowbuf, rlen);
103 spin_lock_irqsave(&cpcmd_lock, flags);
104 len = __cpcmd(cmd, response, rlen, response_code);
105 spin_unlock_irqrestore(&cpcmd_lock, flags);
109 EXPORT_SYMBOL(cpcmd);