Linux 5.1.15
[linux/fpc-iii.git] / drivers / s390 / char / zcore.c
blob76d3c50bf078bc0ce1490a0ec7d571eeac17634a
1 // SPDX-License-Identifier: GPL-1.0+
2 /*
3 * zcore module to export memory content and register sets for creating system
4 * dumps on SCSI disks (zfcpdump). The "zcore/mem" debugfs file shows the same
5 * dump format as s390 standalone dumps.
7 * For more information please refer to Documentation/s390/zfcpdump.txt
9 * Copyright IBM Corp. 2003, 2008
10 * Author(s): Michael Holzheu
13 #define KMSG_COMPONENT "zdump"
14 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
16 #include <linux/init.h>
17 #include <linux/slab.h>
18 #include <linux/debugfs.h>
19 #include <linux/memblock.h>
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"
34 #define TRACE(x...) debug_sprintf_event(zcore_dbf, 1, x)
36 #define CHUNK_INFO_SIZE 34 /* 2 16-byte char, each followed by blank */
38 enum arch_id {
39 ARCH_S390 = 0,
40 ARCH_S390X = 1,
43 struct ipib_info {
44 unsigned long ipib;
45 u32 checksum;
46 } __attribute__((packed));
48 static struct debug_info *zcore_dbf;
49 static int hsa_available;
50 static struct dentry *zcore_dir;
51 static struct dentry *zcore_memmap_file;
52 static struct dentry *zcore_reipl_file;
53 static struct dentry *zcore_hsa_file;
54 static struct ipl_parameter_block *ipl_block;
56 static char hsa_buf[PAGE_SIZE] __aligned(PAGE_SIZE);
59 * Copy memory from HSA to user memory (not reentrant):
61 * @dest: User buffer where memory should be copied to
62 * @src: Start address within HSA where data should be copied
63 * @count: Size of buffer, which should be copied
65 int memcpy_hsa_user(void __user *dest, unsigned long src, size_t count)
67 unsigned long offset, bytes;
69 if (!hsa_available)
70 return -ENODATA;
72 while (count) {
73 if (sclp_sdias_copy(hsa_buf, src / PAGE_SIZE + 2, 1)) {
74 TRACE("sclp_sdias_copy() failed\n");
75 return -EIO;
77 offset = src % PAGE_SIZE;
78 bytes = min(PAGE_SIZE - offset, count);
79 if (copy_to_user(dest, hsa_buf + offset, bytes))
80 return -EFAULT;
81 src += bytes;
82 dest += bytes;
83 count -= bytes;
85 return 0;
89 * Copy memory from HSA to kernel memory (not reentrant):
91 * @dest: Kernel or user buffer where memory should be copied to
92 * @src: Start address within HSA where data should be copied
93 * @count: Size of buffer, which should be copied
95 int memcpy_hsa_kernel(void *dest, unsigned long src, size_t count)
97 unsigned long offset, bytes;
99 if (!hsa_available)
100 return -ENODATA;
102 while (count) {
103 if (sclp_sdias_copy(hsa_buf, src / PAGE_SIZE + 2, 1)) {
104 TRACE("sclp_sdias_copy() failed\n");
105 return -EIO;
107 offset = src % PAGE_SIZE;
108 bytes = min(PAGE_SIZE - offset, count);
109 memcpy(dest, hsa_buf + offset, bytes);
110 src += bytes;
111 dest += bytes;
112 count -= bytes;
114 return 0;
117 static int __init init_cpu_info(void)
119 struct save_area *sa;
121 /* get info for boot cpu from lowcore, stored in the HSA */
122 sa = save_area_boot_cpu();
123 if (!sa)
124 return -ENOMEM;
125 if (memcpy_hsa_kernel(hsa_buf, __LC_FPREGS_SAVE_AREA, 512) < 0) {
126 TRACE("could not copy from HSA\n");
127 return -EIO;
129 save_area_add_regs(sa, hsa_buf); /* vx registers are saved in smp.c */
130 return 0;
134 * Release the HSA
136 static void release_hsa(void)
138 diag308(DIAG308_REL_HSA, NULL);
139 hsa_available = 0;
142 static ssize_t zcore_memmap_read(struct file *filp, char __user *buf,
143 size_t count, loff_t *ppos)
145 return simple_read_from_buffer(buf, count, ppos, filp->private_data,
146 memblock.memory.cnt * CHUNK_INFO_SIZE);
149 static int zcore_memmap_open(struct inode *inode, struct file *filp)
151 struct memblock_region *reg;
152 char *buf;
153 int i = 0;
155 buf = kcalloc(memblock.memory.cnt, CHUNK_INFO_SIZE, GFP_KERNEL);
156 if (!buf) {
157 return -ENOMEM;
159 for_each_memblock(memory, reg) {
160 sprintf(buf + (i++ * CHUNK_INFO_SIZE), "%016llx %016llx ",
161 (unsigned long long) reg->base,
162 (unsigned long long) reg->size);
164 filp->private_data = buf;
165 return nonseekable_open(inode, filp);
168 static int zcore_memmap_release(struct inode *inode, struct file *filp)
170 kfree(filp->private_data);
171 return 0;
174 static const struct file_operations zcore_memmap_fops = {
175 .owner = THIS_MODULE,
176 .read = zcore_memmap_read,
177 .open = zcore_memmap_open,
178 .release = zcore_memmap_release,
179 .llseek = no_llseek,
182 static ssize_t zcore_reipl_write(struct file *filp, const char __user *buf,
183 size_t count, loff_t *ppos)
185 if (ipl_block) {
186 diag308(DIAG308_SET, ipl_block);
187 diag308(DIAG308_LOAD_CLEAR, NULL);
189 return count;
192 static int zcore_reipl_open(struct inode *inode, struct file *filp)
194 return nonseekable_open(inode, filp);
197 static int zcore_reipl_release(struct inode *inode, struct file *filp)
199 return 0;
202 static const struct file_operations zcore_reipl_fops = {
203 .owner = THIS_MODULE,
204 .write = zcore_reipl_write,
205 .open = zcore_reipl_open,
206 .release = zcore_reipl_release,
207 .llseek = no_llseek,
210 static ssize_t zcore_hsa_read(struct file *filp, char __user *buf,
211 size_t count, loff_t *ppos)
213 static char str[18];
215 if (hsa_available)
216 snprintf(str, sizeof(str), "%lx\n", sclp.hsa_size);
217 else
218 snprintf(str, sizeof(str), "0\n");
219 return simple_read_from_buffer(buf, count, ppos, str, strlen(str));
222 static ssize_t zcore_hsa_write(struct file *filp, const char __user *buf,
223 size_t count, loff_t *ppos)
225 char value;
227 if (*ppos != 0)
228 return -EPIPE;
229 if (copy_from_user(&value, buf, 1))
230 return -EFAULT;
231 if (value != '0')
232 return -EINVAL;
233 release_hsa();
234 return count;
237 static const struct file_operations zcore_hsa_fops = {
238 .owner = THIS_MODULE,
239 .write = zcore_hsa_write,
240 .read = zcore_hsa_read,
241 .open = nonseekable_open,
242 .llseek = no_llseek,
245 static int __init check_sdias(void)
247 if (!sclp.hsa_size) {
248 TRACE("Could not determine HSA size\n");
249 return -ENODEV;
251 return 0;
255 * Provide IPL parameter information block from either HSA or memory
256 * for future reipl
258 static int __init zcore_reipl_init(void)
260 struct ipib_info ipib_info;
261 int rc;
263 rc = memcpy_hsa_kernel(&ipib_info, __LC_DUMP_REIPL, sizeof(ipib_info));
264 if (rc)
265 return rc;
266 if (ipib_info.ipib == 0)
267 return 0;
268 ipl_block = (void *) __get_free_page(GFP_KERNEL);
269 if (!ipl_block)
270 return -ENOMEM;
271 if (ipib_info.ipib < sclp.hsa_size)
272 rc = memcpy_hsa_kernel(ipl_block, ipib_info.ipib, PAGE_SIZE);
273 else
274 rc = memcpy_real(ipl_block, (void *) ipib_info.ipib, PAGE_SIZE);
275 if (rc || (__force u32)csum_partial(ipl_block, ipl_block->hdr.len, 0) !=
276 ipib_info.checksum) {
277 TRACE("Checksum does not match\n");
278 free_page((unsigned long) ipl_block);
279 ipl_block = NULL;
281 return 0;
284 static int __init zcore_init(void)
286 unsigned char arch;
287 int rc;
289 if (ipl_info.type != IPL_TYPE_FCP_DUMP)
290 return -ENODATA;
291 if (OLDMEM_BASE)
292 return -ENODATA;
294 zcore_dbf = debug_register("zcore", 4, 1, 4 * sizeof(long));
295 debug_register_view(zcore_dbf, &debug_sprintf_view);
296 debug_set_level(zcore_dbf, 6);
298 TRACE("devno: %x\n", ipl_info.data.fcp.dev_id.devno);
299 TRACE("wwpn: %llx\n", (unsigned long long) ipl_info.data.fcp.wwpn);
300 TRACE("lun: %llx\n", (unsigned long long) ipl_info.data.fcp.lun);
302 rc = sclp_sdias_init();
303 if (rc)
304 goto fail;
306 rc = check_sdias();
307 if (rc)
308 goto fail;
309 hsa_available = 1;
311 rc = memcpy_hsa_kernel(&arch, __LC_AR_MODE_ID, 1);
312 if (rc)
313 goto fail;
315 if (arch == ARCH_S390) {
316 pr_alert("The 64-bit dump tool cannot be used for a "
317 "32-bit system\n");
318 rc = -EINVAL;
319 goto fail;
322 pr_alert("The dump process started for a 64-bit operating system\n");
323 rc = init_cpu_info();
324 if (rc)
325 goto fail;
327 rc = zcore_reipl_init();
328 if (rc)
329 goto fail;
331 zcore_dir = debugfs_create_dir("zcore" , NULL);
332 if (!zcore_dir) {
333 rc = -ENOMEM;
334 goto fail;
336 zcore_memmap_file = debugfs_create_file("memmap", S_IRUSR, zcore_dir,
337 NULL, &zcore_memmap_fops);
338 if (!zcore_memmap_file) {
339 rc = -ENOMEM;
340 goto fail_dir;
342 zcore_reipl_file = debugfs_create_file("reipl", S_IRUSR, zcore_dir,
343 NULL, &zcore_reipl_fops);
344 if (!zcore_reipl_file) {
345 rc = -ENOMEM;
346 goto fail_memmap_file;
348 zcore_hsa_file = debugfs_create_file("hsa", S_IRUSR|S_IWUSR, zcore_dir,
349 NULL, &zcore_hsa_fops);
350 if (!zcore_hsa_file) {
351 rc = -ENOMEM;
352 goto fail_reipl_file;
354 return 0;
356 fail_reipl_file:
357 debugfs_remove(zcore_reipl_file);
358 fail_memmap_file:
359 debugfs_remove(zcore_memmap_file);
360 fail_dir:
361 debugfs_remove(zcore_dir);
362 fail:
363 diag308(DIAG308_REL_HSA, NULL);
364 return rc;
366 subsys_initcall(zcore_init);