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1da177e4 LT |
1 | /* |
2 | * arch/s390/kernel/cpcmd.c | |
3 | * | |
4 | * S390 version | |
a004fb0c | 5 | * Copyright IBM Corp. 1999,2007 |
1da177e4 LT |
6 | * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), |
7 | * Christian Borntraeger (cborntra@de.ibm.com), | |
8 | */ | |
9 | ||
2f526e5a CB |
10 | #define KMSG_COMPONENT "cpcmd" |
11 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt | |
12 | ||
1da177e4 LT |
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> | |
21 | #include <asm/system.h> | |
bda3563f | 22 | #include <asm/io.h> |
1da177e4 LT |
23 | |
24 | static DEFINE_SPINLOCK(cpcmd_lock); | |
6b979de3 | 25 | static char cpcmd_buf[241]; |
1da177e4 | 26 | |
a004fb0c HC |
27 | static int diag8_noresponse(int cmdlen) |
28 | { | |
29 | register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf; | |
30 | register unsigned long reg3 asm ("3") = cmdlen; | |
31 | ||
32 | asm volatile( | |
33 | #ifndef CONFIG_64BIT | |
34 | " diag %1,%0,0x8\n" | |
35 | #else /* CONFIG_64BIT */ | |
36 | " sam31\n" | |
37 | " diag %1,%0,0x8\n" | |
38 | " sam64\n" | |
39 | #endif /* CONFIG_64BIT */ | |
40 | : "+d" (reg3) : "d" (reg2) : "cc"); | |
41 | return reg3; | |
42 | } | |
43 | ||
44 | static int diag8_response(int cmdlen, char *response, int *rlen) | |
45 | { | |
46 | register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf; | |
47 | register unsigned long reg3 asm ("3") = (addr_t) response; | |
48 | register unsigned long reg4 asm ("4") = cmdlen | 0x40000000L; | |
49 | register unsigned long reg5 asm ("5") = *rlen; | |
50 | ||
51 | asm volatile( | |
52 | #ifndef CONFIG_64BIT | |
53 | " diag %2,%0,0x8\n" | |
54 | " brc 8,1f\n" | |
55 | " ar %1,%4\n" | |
56 | #else /* CONFIG_64BIT */ | |
57 | " sam31\n" | |
58 | " diag %2,%0,0x8\n" | |
59 | " sam64\n" | |
60 | " brc 8,1f\n" | |
61 | " agr %1,%4\n" | |
62 | #endif /* CONFIG_64BIT */ | |
63 | "1:\n" | |
64 | : "+d" (reg4), "+d" (reg5) | |
65 | : "d" (reg2), "d" (reg3), "d" (*rlen) : "cc"); | |
66 | *rlen = reg5; | |
67 | return reg4; | |
68 | } | |
69 | ||
1da177e4 | 70 | /* |
740b5706 HC |
71 | * __cpcmd has some restrictions over cpcmd |
72 | * - the response buffer must reside below 2GB (if any) | |
73 | * - __cpcmd is unlocked and therefore not SMP-safe | |
1da177e4 | 74 | */ |
6b979de3 | 75 | int __cpcmd(const char *cmd, char *response, int rlen, int *response_code) |
1da177e4 | 76 | { |
a004fb0c HC |
77 | int cmdlen; |
78 | int rc; | |
79 | int response_len; | |
1da177e4 | 80 | |
1da177e4 LT |
81 | cmdlen = strlen(cmd); |
82 | BUG_ON(cmdlen > 240); | |
6b979de3 | 83 | memcpy(cpcmd_buf, cmd, cmdlen); |
1da177e4 LT |
84 | ASCEBC(cpcmd_buf, cmdlen); |
85 | ||
a004fb0c | 86 | if (response) { |
1da177e4 | 87 | memset(response, 0, rlen); |
a004fb0c HC |
88 | response_len = rlen; |
89 | rc = diag8_response(cmdlen, response, &rlen); | |
90 | EBCASC(response, response_len); | |
1da177e4 | 91 | } else { |
a004fb0c | 92 | rc = diag8_noresponse(cmdlen); |
1da177e4 | 93 | } |
a004fb0c HC |
94 | if (response_code) |
95 | *response_code = rc; | |
96 | return rlen; | |
1da177e4 | 97 | } |
1da177e4 LT |
98 | EXPORT_SYMBOL(__cpcmd); |
99 | ||
6b979de3 | 100 | int cpcmd(const char *cmd, char *response, int rlen, int *response_code) |
1da177e4 LT |
101 | { |
102 | char *lowbuf; | |
6b979de3 | 103 | int len; |
740b5706 | 104 | unsigned long flags; |
6b979de3 | 105 | |
bda3563f CB |
106 | if ((virt_to_phys(response) != (unsigned long) response) || |
107 | (((unsigned long)response + rlen) >> 31)) { | |
1da177e4 LT |
108 | lowbuf = kmalloc(rlen, GFP_KERNEL | GFP_DMA); |
109 | if (!lowbuf) { | |
2f526e5a CB |
110 | pr_warning("The cpcmd kernel function failed to " |
111 | "allocate a response buffer\n"); | |
6b979de3 | 112 | return -ENOMEM; |
1da177e4 | 113 | } |
740b5706 | 114 | spin_lock_irqsave(&cpcmd_lock, flags); |
6b979de3 | 115 | len = __cpcmd(cmd, lowbuf, rlen, response_code); |
740b5706 | 116 | spin_unlock_irqrestore(&cpcmd_lock, flags); |
1da177e4 LT |
117 | memcpy(response, lowbuf, rlen); |
118 | kfree(lowbuf); | |
bda3563f CB |
119 | } else { |
120 | spin_lock_irqsave(&cpcmd_lock, flags); | |
121 | len = __cpcmd(cmd, response, rlen, response_code); | |
122 | spin_unlock_irqrestore(&cpcmd_lock, flags); | |
1da177e4 | 123 | } |
6b979de3 | 124 | return len; |
1da177e4 | 125 | } |
1da177e4 | 126 | EXPORT_SYMBOL(cpcmd); |