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1da177e4 LT |
1 | /* |
2 | * c 2001 PPC 64 Team, IBM Corp | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; either version | |
7 | * 2 of the License, or (at your option) any later version. | |
8 | * | |
9 | * /dev/nvram driver for PPC64 | |
10 | * | |
11 | * This perhaps should live in drivers/char | |
12 | */ | |
13 | ||
14 | ||
15 | #include <linux/types.h> | |
16 | #include <linux/errno.h> | |
17 | #include <linux/init.h> | |
1da177e4 | 18 | #include <linux/spinlock.h> |
a5cf4b08 | 19 | #include <linux/slab.h> |
6c493685 | 20 | #include <linux/ctype.h> |
7c0f6ba6 | 21 | #include <linux/uaccess.h> |
1da177e4 LT |
22 | #include <asm/nvram.h> |
23 | #include <asm/rtas.h> | |
24 | #include <asm/prom.h> | |
25 | #include <asm/machdep.h> | |
26 | ||
4e7c77a3 BH |
27 | /* Max bytes to read/write in one go */ |
28 | #define NVRW_CNT 0x20 | |
29 | ||
1da177e4 LT |
30 | static unsigned int nvram_size; |
31 | static int nvram_fetch, nvram_store; | |
32 | static char nvram_buf[NVRW_CNT]; /* assume this is in the first 4GB */ | |
33 | static DEFINE_SPINLOCK(nvram_lock); | |
34 | ||
a5cf4b08 JK |
35 | /* See clobbering_unread_rtas_event() */ |
36 | #define NVRAM_RTAS_READ_TIMEOUT 5 /* seconds */ | |
e4a9616c | 37 | static time64_t last_unread_rtas_event; /* timestamp */ |
a5cf4b08 | 38 | |
d7563c94 | 39 | #ifdef CONFIG_PSTORE |
e4a9616c | 40 | time64_t last_rtas_event; |
d7563c94 AB |
41 | #endif |
42 | ||
1da177e4 LT |
43 | static ssize_t pSeries_nvram_read(char *buf, size_t count, loff_t *index) |
44 | { | |
45 | unsigned int i; | |
46 | unsigned long len; | |
47 | int done; | |
48 | unsigned long flags; | |
49 | char *p = buf; | |
50 | ||
51 | ||
52 | if (nvram_size == 0 || nvram_fetch == RTAS_UNKNOWN_SERVICE) | |
53 | return -ENODEV; | |
54 | ||
55 | if (*index >= nvram_size) | |
56 | return 0; | |
57 | ||
58 | i = *index; | |
59 | if (i + count > nvram_size) | |
60 | count = nvram_size - i; | |
61 | ||
62 | spin_lock_irqsave(&nvram_lock, flags); | |
63 | ||
64 | for (; count != 0; count -= len) { | |
65 | len = count; | |
66 | if (len > NVRW_CNT) | |
67 | len = NVRW_CNT; | |
68 | ||
69 | if ((rtas_call(nvram_fetch, 3, 2, &done, i, __pa(nvram_buf), | |
70 | len) != 0) || len != done) { | |
71 | spin_unlock_irqrestore(&nvram_lock, flags); | |
72 | return -EIO; | |
73 | } | |
74 | ||
75 | memcpy(p, nvram_buf, len); | |
76 | ||
77 | p += len; | |
78 | i += len; | |
79 | } | |
80 | ||
81 | spin_unlock_irqrestore(&nvram_lock, flags); | |
82 | ||
83 | *index = i; | |
84 | return p - buf; | |
85 | } | |
86 | ||
87 | static ssize_t pSeries_nvram_write(char *buf, size_t count, loff_t *index) | |
88 | { | |
89 | unsigned int i; | |
90 | unsigned long len; | |
91 | int done; | |
92 | unsigned long flags; | |
93 | const char *p = buf; | |
94 | ||
95 | if (nvram_size == 0 || nvram_store == RTAS_UNKNOWN_SERVICE) | |
96 | return -ENODEV; | |
97 | ||
98 | if (*index >= nvram_size) | |
99 | return 0; | |
100 | ||
101 | i = *index; | |
102 | if (i + count > nvram_size) | |
103 | count = nvram_size - i; | |
104 | ||
105 | spin_lock_irqsave(&nvram_lock, flags); | |
106 | ||
107 | for (; count != 0; count -= len) { | |
108 | len = count; | |
109 | if (len > NVRW_CNT) | |
110 | len = NVRW_CNT; | |
111 | ||
112 | memcpy(nvram_buf, p, len); | |
113 | ||
114 | if ((rtas_call(nvram_store, 3, 2, &done, i, __pa(nvram_buf), | |
115 | len) != 0) || len != done) { | |
116 | spin_unlock_irqrestore(&nvram_lock, flags); | |
117 | return -EIO; | |
118 | } | |
119 | ||
120 | p += len; | |
121 | i += len; | |
122 | } | |
123 | spin_unlock_irqrestore(&nvram_lock, flags); | |
124 | ||
125 | *index = i; | |
126 | return p - buf; | |
127 | } | |
128 | ||
129 | static ssize_t pSeries_nvram_get_size(void) | |
130 | { | |
131 | return nvram_size ? nvram_size : -ENODEV; | |
132 | } | |
133 | ||
78989f0a | 134 | /* nvram_write_error_log |
edc79a2f BH |
135 | * |
136 | * We need to buffer the error logs into nvram to ensure that we have | |
78989f0a | 137 | * the failure information to decode. |
edc79a2f | 138 | */ |
0f4ac132 JK |
139 | int nvram_write_error_log(char * buff, int length, |
140 | unsigned int err_type, unsigned int error_log_cnt) | |
141 | { | |
a5cf4b08 | 142 | int rc = nvram_write_os_partition(&rtas_log_partition, buff, length, |
0f4ac132 | 143 | err_type, error_log_cnt); |
69020eea | 144 | if (!rc) { |
e4a9616c | 145 | last_unread_rtas_event = ktime_get_real_seconds(); |
69020eea | 146 | #ifdef CONFIG_PSTORE |
e4a9616c | 147 | last_rtas_event = ktime_get_real_seconds(); |
69020eea AB |
148 | #endif |
149 | } | |
150 | ||
a5cf4b08 | 151 | return rc; |
0f4ac132 JK |
152 | } |
153 | ||
12674610 AB |
154 | /* nvram_read_error_log |
155 | * | |
156 | * Reads nvram for error log for at most 'length' | |
157 | */ | |
158 | int nvram_read_error_log(char *buff, int length, | |
159 | unsigned int *err_type, unsigned int *error_log_cnt) | |
160 | { | |
161 | return nvram_read_partition(&rtas_log_partition, buff, length, | |
162 | err_type, error_log_cnt); | |
163 | } | |
164 | ||
edc79a2f BH |
165 | /* This doesn't actually zero anything, but it sets the event_logged |
166 | * word to tell that this event is safely in syslog. | |
167 | */ | |
168 | int nvram_clear_error_log(void) | |
169 | { | |
170 | loff_t tmp_index; | |
171 | int clear_word = ERR_FLAG_ALREADY_LOGGED; | |
172 | int rc; | |
173 | ||
0f4ac132 | 174 | if (rtas_log_partition.index == -1) |
edc79a2f BH |
175 | return -1; |
176 | ||
0f4ac132 | 177 | tmp_index = rtas_log_partition.index; |
edc79a2f BH |
178 | |
179 | rc = ppc_md.nvram_write((char *)&clear_word, sizeof(int), &tmp_index); | |
180 | if (rc <= 0) { | |
181 | printk(KERN_ERR "nvram_clear_error_log: Failed nvram_write (%d)\n", rc); | |
182 | return rc; | |
183 | } | |
a5cf4b08 | 184 | last_unread_rtas_event = 0; |
edc79a2f BH |
185 | |
186 | return 0; | |
187 | } | |
188 | ||
d7563c94 AB |
189 | /* |
190 | * Are we using the ibm,rtas-log for oops/panic reports? And if so, | |
191 | * would logging this oops/panic overwrite an RTAS event that rtas_errd | |
192 | * hasn't had a chance to read and process? Return 1 if so, else 0. | |
193 | * | |
194 | * We assume that if rtas_errd hasn't read the RTAS event in | |
195 | * NVRAM_RTAS_READ_TIMEOUT seconds, it's probably not going to. | |
196 | */ | |
78989f0a | 197 | int clobbering_unread_rtas_event(void) |
d7563c94 AB |
198 | { |
199 | return (oops_log_partition.index == rtas_log_partition.index | |
200 | && last_unread_rtas_event | |
e4a9616c | 201 | && ktime_get_real_seconds() - last_unread_rtas_event <= |
d7563c94 AB |
202 | NVRAM_RTAS_READ_TIMEOUT); |
203 | } | |
204 | ||
0f4ac132 JK |
205 | static int __init pseries_nvram_init_log_partitions(void) |
206 | { | |
a5cf4b08 JK |
207 | int rc; |
208 | ||
65f36f41 CLG |
209 | /* Scan nvram for partitions */ |
210 | nvram_scan_partitions(); | |
211 | ||
78989f0a | 212 | rc = nvram_init_os_partition(&rtas_log_partition); |
a5cf4b08 | 213 | nvram_init_oops_partition(rc == 0); |
0f4ac132 JK |
214 | return 0; |
215 | } | |
216 | machine_arch_initcall(pseries, pseries_nvram_init_log_partitions); | |
edc79a2f | 217 | |
1da177e4 LT |
218 | int __init pSeries_nvram_init(void) |
219 | { | |
220 | struct device_node *nvram; | |
563c5d8a | 221 | const __be32 *nbytes_p; |
954a46e2 | 222 | unsigned int proplen; |
1da177e4 LT |
223 | |
224 | nvram = of_find_node_by_type(NULL, "nvram"); | |
225 | if (nvram == NULL) | |
226 | return -ENODEV; | |
227 | ||
e2eb6392 | 228 | nbytes_p = of_get_property(nvram, "#bytes", &proplen); |
bad5232b JL |
229 | if (nbytes_p == NULL || proplen != sizeof(unsigned int)) { |
230 | of_node_put(nvram); | |
1da177e4 | 231 | return -EIO; |
bad5232b | 232 | } |
1da177e4 | 233 | |
563c5d8a | 234 | nvram_size = be32_to_cpup(nbytes_p); |
1da177e4 LT |
235 | |
236 | nvram_fetch = rtas_token("nvram-fetch"); | |
237 | nvram_store = rtas_token("nvram-store"); | |
238 | printk(KERN_INFO "PPC64 nvram contains %d bytes\n", nvram_size); | |
239 | of_node_put(nvram); | |
240 | ||
241 | ppc_md.nvram_read = pSeries_nvram_read; | |
242 | ppc_md.nvram_write = pSeries_nvram_write; | |
243 | ppc_md.nvram_size = pSeries_nvram_get_size; | |
244 | ||
245 | return 0; | |
246 | } | |
a5cf4b08 | 247 |