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12#define KMSG_COMPONENT "zdump"
13#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
14
15#include <linux/init.h>
16#include <linux/slab.h>
17#include <linux/debugfs.h>
18#include <linux/panic_notifier.h>
19#include <linux/reboot.h>
20
21#include <asm/asm-offsets.h>
22#include <asm/ipl.h>
23#include <asm/sclp.h>
24#include <asm/setup.h>
25#include <linux/uaccess.h>
26#include <asm/debug.h>
27#include <asm/processor.h>
28#include <asm/irqflags.h>
29#include <asm/checksum.h>
30#include <asm/os_info.h>
31#include <asm/switch_to.h>
32#include "sclp.h"
33
34#define TRACE(x...) debug_sprintf_event(zcore_dbf, 1, x)
35
36enum arch_id {
37 ARCH_S390 = 0,
38 ARCH_S390X = 1,
39};
40
41struct ipib_info {
42 unsigned long ipib;
43 u32 checksum;
44} __attribute__((packed));
45
46static struct debug_info *zcore_dbf;
47static int hsa_available;
48static struct dentry *zcore_dir;
49static struct dentry *zcore_reipl_file;
50static struct dentry *zcore_hsa_file;
51static struct ipl_parameter_block *zcore_ipl_block;
52
53static char hsa_buf[PAGE_SIZE] __aligned(PAGE_SIZE);
54
55
56
57
58
59
60
61
62int memcpy_hsa_user(void __user *dest, unsigned long src, size_t count)
63{
64 unsigned long offset, bytes;
65
66 if (!hsa_available)
67 return -ENODATA;
68
69 while (count) {
70 if (sclp_sdias_copy(hsa_buf, src / PAGE_SIZE + 2, 1)) {
71 TRACE("sclp_sdias_copy() failed\n");
72 return -EIO;
73 }
74 offset = src % PAGE_SIZE;
75 bytes = min(PAGE_SIZE - offset, count);
76 if (copy_to_user(dest, hsa_buf + offset, bytes))
77 return -EFAULT;
78 src += bytes;
79 dest += bytes;
80 count -= bytes;
81 }
82 return 0;
83}
84
85
86
87
88
89
90
91
92int memcpy_hsa_kernel(void *dest, unsigned long src, size_t count)
93{
94 unsigned long offset, bytes;
95
96 if (!hsa_available)
97 return -ENODATA;
98
99 while (count) {
100 if (sclp_sdias_copy(hsa_buf, src / PAGE_SIZE + 2, 1)) {
101 TRACE("sclp_sdias_copy() failed\n");
102 return -EIO;
103 }
104 offset = src % PAGE_SIZE;
105 bytes = min(PAGE_SIZE - offset, count);
106 memcpy(dest, hsa_buf + offset, bytes);
107 src += bytes;
108 dest += bytes;
109 count -= bytes;
110 }
111 return 0;
112}
113
114static int __init init_cpu_info(void)
115{
116 struct save_area *sa;
117
118
119 sa = save_area_boot_cpu();
120 if (!sa)
121 return -ENOMEM;
122 if (memcpy_hsa_kernel(hsa_buf, __LC_FPREGS_SAVE_AREA, 512) < 0) {
123 TRACE("could not copy from HSA\n");
124 return -EIO;
125 }
126 save_area_add_regs(sa, hsa_buf);
127 return 0;
128}
129
130
131
132
133static void release_hsa(void)
134{
135 diag308(DIAG308_REL_HSA, NULL);
136 hsa_available = 0;
137}
138
139static ssize_t zcore_reipl_write(struct file *filp, const char __user *buf,
140 size_t count, loff_t *ppos)
141{
142 if (zcore_ipl_block) {
143 diag308(DIAG308_SET, zcore_ipl_block);
144 diag308(DIAG308_LOAD_CLEAR, NULL);
145 }
146 return count;
147}
148
149static int zcore_reipl_open(struct inode *inode, struct file *filp)
150{
151 return stream_open(inode, filp);
152}
153
154static int zcore_reipl_release(struct inode *inode, struct file *filp)
155{
156 return 0;
157}
158
159static const struct file_operations zcore_reipl_fops = {
160 .owner = THIS_MODULE,
161 .write = zcore_reipl_write,
162 .open = zcore_reipl_open,
163 .release = zcore_reipl_release,
164 .llseek = no_llseek,
165};
166
167static ssize_t zcore_hsa_read(struct file *filp, char __user *buf,
168 size_t count, loff_t *ppos)
169{
170 static char str[18];
171
172 if (hsa_available)
173 snprintf(str, sizeof(str), "%lx\n", sclp.hsa_size);
174 else
175 snprintf(str, sizeof(str), "0\n");
176 return simple_read_from_buffer(buf, count, ppos, str, strlen(str));
177}
178
179static ssize_t zcore_hsa_write(struct file *filp, const char __user *buf,
180 size_t count, loff_t *ppos)
181{
182 char value;
183
184 if (*ppos != 0)
185 return -EPIPE;
186 if (copy_from_user(&value, buf, 1))
187 return -EFAULT;
188 if (value != '0')
189 return -EINVAL;
190 release_hsa();
191 return count;
192}
193
194static const struct file_operations zcore_hsa_fops = {
195 .owner = THIS_MODULE,
196 .write = zcore_hsa_write,
197 .read = zcore_hsa_read,
198 .open = nonseekable_open,
199 .llseek = no_llseek,
200};
201
202static int __init check_sdias(void)
203{
204 if (!sclp.hsa_size) {
205 TRACE("Could not determine HSA size\n");
206 return -ENODEV;
207 }
208 return 0;
209}
210
211
212
213
214
215static int __init zcore_reipl_init(void)
216{
217 struct ipib_info ipib_info;
218 int rc;
219
220 rc = memcpy_hsa_kernel(&ipib_info, __LC_DUMP_REIPL, sizeof(ipib_info));
221 if (rc)
222 return rc;
223 if (ipib_info.ipib == 0)
224 return 0;
225 zcore_ipl_block = (void *) __get_free_page(GFP_KERNEL);
226 if (!zcore_ipl_block)
227 return -ENOMEM;
228 if (ipib_info.ipib < sclp.hsa_size)
229 rc = memcpy_hsa_kernel(zcore_ipl_block, ipib_info.ipib,
230 PAGE_SIZE);
231 else
232 rc = memcpy_real(zcore_ipl_block, (void *) ipib_info.ipib,
233 PAGE_SIZE);
234 if (rc || (__force u32)csum_partial(zcore_ipl_block, zcore_ipl_block->hdr.len, 0) !=
235 ipib_info.checksum) {
236 TRACE("Checksum does not match\n");
237 free_page((unsigned long) zcore_ipl_block);
238 zcore_ipl_block = NULL;
239 }
240 return 0;
241}
242
243static int zcore_reboot_and_on_panic_handler(struct notifier_block *self,
244 unsigned long event,
245 void *data)
246{
247 if (hsa_available)
248 release_hsa();
249
250 return NOTIFY_OK;
251}
252
253static struct notifier_block zcore_reboot_notifier = {
254 .notifier_call = zcore_reboot_and_on_panic_handler,
255
256 .priority = INT_MAX,
257};
258
259static struct notifier_block zcore_on_panic_notifier = {
260 .notifier_call = zcore_reboot_and_on_panic_handler,
261
262 .priority = INT_MAX,
263};
264
265static int __init zcore_init(void)
266{
267 unsigned char arch;
268 int rc;
269
270 if (!is_ipl_type_dump())
271 return -ENODATA;
272 if (oldmem_data.start)
273 return -ENODATA;
274
275 zcore_dbf = debug_register("zcore", 4, 1, 4 * sizeof(long));
276 debug_register_view(zcore_dbf, &debug_sprintf_view);
277 debug_set_level(zcore_dbf, 6);
278
279 if (ipl_info.type == IPL_TYPE_FCP_DUMP) {
280 TRACE("type: fcp\n");
281 TRACE("devno: %x\n", ipl_info.data.fcp.dev_id.devno);
282 TRACE("wwpn: %llx\n", (unsigned long long) ipl_info.data.fcp.wwpn);
283 TRACE("lun: %llx\n", (unsigned long long) ipl_info.data.fcp.lun);
284 } else if (ipl_info.type == IPL_TYPE_NVME_DUMP) {
285 TRACE("type: nvme\n");
286 TRACE("fid: %x\n", ipl_info.data.nvme.fid);
287 TRACE("nsid: %x\n", ipl_info.data.nvme.nsid);
288 }
289
290 rc = sclp_sdias_init();
291 if (rc)
292 goto fail;
293
294 rc = check_sdias();
295 if (rc)
296 goto fail;
297 hsa_available = 1;
298
299 rc = memcpy_hsa_kernel(&arch, __LC_AR_MODE_ID, 1);
300 if (rc)
301 goto fail;
302
303 if (arch == ARCH_S390) {
304 pr_alert("The 64-bit dump tool cannot be used for a "
305 "32-bit system\n");
306 rc = -EINVAL;
307 goto fail;
308 }
309
310 pr_alert("The dump process started for a 64-bit operating system\n");
311 rc = init_cpu_info();
312 if (rc)
313 goto fail;
314
315 rc = zcore_reipl_init();
316 if (rc)
317 goto fail;
318
319 zcore_dir = debugfs_create_dir("zcore" , NULL);
320 zcore_reipl_file = debugfs_create_file("reipl", S_IRUSR, zcore_dir,
321 NULL, &zcore_reipl_fops);
322 zcore_hsa_file = debugfs_create_file("hsa", S_IRUSR|S_IWUSR, zcore_dir,
323 NULL, &zcore_hsa_fops);
324
325 register_reboot_notifier(&zcore_reboot_notifier);
326 atomic_notifier_chain_register(&panic_notifier_list, &zcore_on_panic_notifier);
327
328 return 0;
329fail:
330 diag308(DIAG308_REL_HSA, NULL);
331 return rc;
332}
333subsys_initcall(zcore_init);
334
