1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
/*
* c 2001 PPC 64 Team, IBM Corp
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* /dev/nvram driver for PPC64
*
* This perhaps should live in drivers/char
*/
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <asm/uaccess.h>
#include <asm/nvram.h>
#include <asm/rtas.h>
#include <asm/prom.h>
#include <asm/machdep.h>
static unsigned int nvram_size;
static int nvram_fetch, nvram_store;
static char nvram_buf[NVRW_CNT]; /* assume this is in the first 4GB */
static DEFINE_SPINLOCK(nvram_lock);
static ssize_t pSeries_nvram_read(char *buf, size_t count, loff_t *index)
{
unsigned int i;
unsigned long len;
int done;
unsigned long flags;
char *p = buf;
if (nvram_size == 0 || nvram_fetch == RTAS_UNKNOWN_SERVICE)
return -ENODEV;
if (*index >= nvram_size)
return 0;
i = *index;
if (i + count > nvram_size)
count = nvram_size - i;
spin_lock_irqsave(&nvram_lock, flags);
for (; count != 0; count -= len) {
len = count;
if (len > NVRW_CNT)
len = NVRW_CNT;
if ((rtas_call(nvram_fetch, 3, 2, &done, i, __pa(nvram_buf),
len) != 0) || len != done) {
spin_unlock_irqrestore(&nvram_lock, flags);
return -EIO;
}
memcpy(p, nvram_buf, len);
p += len;
i += len;
}
spin_unlock_irqrestore(&nvram_lock, flags);
*index = i;
return p - buf;
}
static ssize_t pSeries_nvram_write(char *buf, size_t count, loff_t *index)
{
unsigned int i;
unsigned long len;
int done;
unsigned long flags;
const char *p = buf;
if (nvram_size == 0 || nvram_store == RTAS_UNKNOWN_SERVICE)
return -ENODEV;
if (*index >= nvram_size)
return 0;
i = *index;
if (i + count > nvram_size)
count = nvram_size - i;
spin_lock_irqsave(&nvram_lock, flags);
for (; count != 0; count -= len) {
len = count;
if (len > NVRW_CNT)
len = NVRW_CNT;
memcpy(nvram_buf, p, len);
if ((rtas_call(nvram_store, 3, 2, &done, i, __pa(nvram_buf),
len) != 0) || len != done) {
spin_unlock_irqrestore(&nvram_lock, flags);
return -EIO;
}
p += len;
i += len;
}
spin_unlock_irqrestore(&nvram_lock, flags);
*index = i;
return p - buf;
}
static ssize_t pSeries_nvram_get_size(void)
{
return nvram_size ? nvram_size : -ENODEV;
}
int __init pSeries_nvram_init(void)
{
struct device_node *nvram;
const unsigned int *nbytes_p;
unsigned int proplen;
nvram = of_find_node_by_type(NULL, "nvram");
if (nvram == NULL)
return -ENODEV;
nbytes_p = of_get_property(nvram, "#bytes", &proplen);
if (nbytes_p == NULL || proplen != sizeof(unsigned int))
return -EIO;
nvram_size = *nbytes_p;
nvram_fetch = rtas_token("nvram-fetch");
nvram_store = rtas_token("nvram-store");
printk(KERN_INFO "PPC64 nvram contains %d bytes\n", nvram_size);
of_node_put(nvram);
ppc_md.nvram_read = pSeries_nvram_read;
ppc_md.nvram_write = pSeries_nvram_write;
ppc_md.nvram_size = pSeries_nvram_get_size;
return 0;
}
|
