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/module.h>
13 #include <linux/slab.h>
14 #include <linux/spinlock.h>
15 #include <linux/stddef.h>
16 #include <linux/string.h>
18 #include <asm/ebcdic.h>
19 #include <asm/cpcmd.h>
22 static DEFINE_SPINLOCK(cpcmd_lock);
23 static char cpcmd_buf[241];
25 static int diag8_noresponse(int cmdlen)
27 register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
28 register unsigned long reg3 asm ("3") = cmdlen;
34 : "+d" (reg3) : "d" (reg2) : "cc");
38 static int diag8_response(int cmdlen, char *response, int *rlen)
40 register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
41 register unsigned long reg3 asm ("3") = (addr_t) response;
42 register unsigned long reg4 asm ("4") = cmdlen | 0x40000000L;
43 register unsigned long reg5 asm ("5") = *rlen;
52 : "+d" (reg4), "+d" (reg5)
53 : "d" (reg2), "d" (reg3), "d" (*rlen) : "cc");
59 * __cpcmd has some restrictions over cpcmd
60 * - the response buffer must reside below 2GB (if any)
61 * - __cpcmd is unlocked and therefore not SMP-safe
63 int __cpcmd(const char *cmd, char *response, int rlen, int *response_code)
71 memcpy(cpcmd_buf, cmd, cmdlen);
72 ASCEBC(cpcmd_buf, cmdlen);
74 diag_stat_inc(DIAG_STAT_X008);
76 memset(response, 0, rlen);
78 rc = diag8_response(cmdlen, response, &rlen);
79 EBCASC(response, response_len);
81 rc = diag8_noresponse(cmdlen);
87 EXPORT_SYMBOL(__cpcmd);
89 int cpcmd(const char *cmd, char *response, int rlen, int *response_code)
95 if ((virt_to_phys(response) != (unsigned long) response) ||
96 (((unsigned long)response + rlen) >> 31)) {
97 lowbuf = kmalloc(rlen, GFP_KERNEL | GFP_DMA);
99 pr_warning("The cpcmd kernel function failed to "
100 "allocate a response buffer\n");
103 spin_lock_irqsave(&cpcmd_lock, flags);
104 len = __cpcmd(cmd, lowbuf, rlen, response_code);
105 spin_unlock_irqrestore(&cpcmd_lock, flags);
106 memcpy(response, lowbuf, rlen);
109 spin_lock_irqsave(&cpcmd_lock, flags);
110 len = __cpcmd(cmd, response, rlen, response_code);
111 spin_unlock_irqrestore(&cpcmd_lock, flags);
115 EXPORT_SYMBOL(cpcmd);