1 // SPDX-License-Identifier: GPL-2.0
4 * Copyright IBM Corp. 1999, 2007
5 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
6 * Christian Borntraeger (cborntra@de.ibm.com),
9 #define KMSG_COMPONENT "cpcmd"
10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
12 #include <linux/kernel.h>
13 #include <linux/export.h>
14 #include <linux/slab.h>
15 #include <linux/spinlock.h>
16 #include <linux/stddef.h>
17 #include <linux/string.h>
20 #include <asm/ebcdic.h>
21 #include <asm/cpcmd.h>
24 static DEFINE_SPINLOCK(cpcmd_lock);
25 static char cpcmd_buf[241];
27 static int diag8_noresponse(int cmdlen)
29 register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
30 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 unsigned long _cmdlen = cmdlen | 0x40000000L;
41 unsigned long _rlen = *rlen;
42 register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
43 register unsigned long reg3 asm ("3") = (addr_t) response;
44 register unsigned long reg4 asm ("4") = _cmdlen;
45 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 * - __cpcmd is unlocked and therefore not SMP-safe
62 int __cpcmd(const char *cmd, char *response, int rlen, int *response_code)
70 memcpy(cpcmd_buf, cmd, cmdlen);
71 ASCEBC(cpcmd_buf, cmdlen);
73 diag_stat_inc(DIAG_STAT_X008);
75 memset(response, 0, rlen);
77 rc = diag8_response(cmdlen, response, &rlen);
78 EBCASC(response, response_len);
80 rc = diag8_noresponse(cmdlen);
86 EXPORT_SYMBOL(__cpcmd);
88 int cpcmd(const char *cmd, char *response, int rlen, int *response_code)
94 if (is_vmalloc_or_module_addr(response)) {
95 lowbuf = kmalloc(rlen, GFP_KERNEL);
97 pr_warn("The cpcmd kernel function failed to allocate a response buffer\n");
100 spin_lock_irqsave(&cpcmd_lock, flags);
101 len = __cpcmd(cmd, lowbuf, rlen, response_code);
102 spin_unlock_irqrestore(&cpcmd_lock, flags);
103 memcpy(response, lowbuf, rlen);
106 spin_lock_irqsave(&cpcmd_lock, flags);
107 len = __cpcmd(cmd, response, rlen, response_code);
108 spin_unlock_irqrestore(&cpcmd_lock, flags);
112 EXPORT_SYMBOL(cpcmd);