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/NVMe disks (zfcp/nvme dump). 5 * 6 * For more information please refer to Documentation/s390/zfcpdump.rst 7 * 8 * Copyright IBM Corp. 2003, 2008 9 * Author(s): Michael Holzheu 10 */ 11 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 19 #include <asm/asm-offsets.h> 20 #include <asm/ipl.h> 21 #include <asm/sclp.h> 22 #include <asm/setup.h> 23 #include <linux/uaccess.h> 24 #include <asm/debug.h> 25 #include <asm/processor.h> 26 #include <asm/irqflags.h> 27 #include <asm/checksum.h> 28 #include <asm/os_info.h> 29 #include <asm/switch_to.h> 30 #include "sclp.h" 31 32 #define TRACE(x...) debug_sprintf_event(zcore_dbf, 1, x) 33 34 enum arch_id { 35 ARCH_S390 = 0, 36 ARCH_S390X = 1, 37 }; 38 39 struct ipib_info { 40 unsigned long ipib; 41 u32 checksum; 42 } __attribute__((packed)); 43 44 static struct debug_info *zcore_dbf; 45 static int hsa_available; 46 static struct dentry *zcore_dir; 47 static struct dentry *zcore_reipl_file; 48 static struct dentry *zcore_hsa_file; 49 static struct ipl_parameter_block *zcore_ipl_block; 50 51 static char hsa_buf[PAGE_SIZE] __aligned(PAGE_SIZE); 52 53 /* 54 * Copy memory from HSA to user memory (not reentrant): 55 * 56 * @dest: User buffer where memory should be copied to 57 * @src: Start address within HSA where data should be copied 58 * @count: Size of buffer, which should be copied 59 */ 60 int memcpy_hsa_user(void __user *dest, unsigned long src, size_t count) 61 { 62 unsigned long offset, bytes; 63 64 if (!hsa_available) 65 return -ENODATA; 66 67 while (count) { 68 if (sclp_sdias_copy(hsa_buf, src / PAGE_SIZE + 2, 1)) { 69 TRACE("sclp_sdias_copy() failed\n"); 70 return -EIO; 71 } 72 offset = src % PAGE_SIZE; 73 bytes = min(PAGE_SIZE - offset, count); 74 if (copy_to_user(dest, hsa_buf + offset, bytes)) 75 return -EFAULT; 76 src += bytes; 77 dest += bytes; 78 count -= bytes; 79 } 80 return 0; 81 } 82 83 /* 84 * Copy memory from HSA to kernel memory (not reentrant): 85 * 86 * @dest: Kernel or user buffer where memory should be copied to 87 * @src: Start address within HSA where data should be copied 88 * @count: Size of buffer, which should be copied 89 */ 90 int memcpy_hsa_kernel(void *dest, unsigned long src, size_t count) 91 { 92 unsigned long offset, bytes; 93 94 if (!hsa_available) 95 return -ENODATA; 96 97 while (count) { 98 if (sclp_sdias_copy(hsa_buf, src / PAGE_SIZE + 2, 1)) { 99 TRACE("sclp_sdias_copy() failed\n"); 100 return -EIO; 101 } 102 offset = src % PAGE_SIZE; 103 bytes = min(PAGE_SIZE - offset, count); 104 memcpy(dest, hsa_buf + offset, bytes); 105 src += bytes; 106 dest += bytes; 107 count -= bytes; 108 } 109 return 0; 110 } 111 112 static int __init init_cpu_info(void) 113 { 114 struct save_area *sa; 115 116 /* get info for boot cpu from lowcore, stored in the HSA */ 117 sa = save_area_boot_cpu(); 118 if (!sa) 119 return -ENOMEM; 120 if (memcpy_hsa_kernel(hsa_buf, __LC_FPREGS_SAVE_AREA, 512) < 0) { 121 TRACE("could not copy from HSA\n"); 122 return -EIO; 123 } 124 save_area_add_regs(sa, hsa_buf); /* vx registers are saved in smp.c */ 125 return 0; 126 } 127 128 /* 129 * Release the HSA 130 */ 131 static void release_hsa(void) 132 { 133 diag308(DIAG308_REL_HSA, NULL); 134 hsa_available = 0; 135 } 136 137 static ssize_t zcore_reipl_write(struct file *filp, const char __user *buf, 138 size_t count, loff_t *ppos) 139 { 140 if (zcore_ipl_block) { 141 diag308(DIAG308_SET, zcore_ipl_block); 142 diag308(DIAG308_LOAD_CLEAR, NULL); 143 } 144 return count; 145 } 146 147 static int zcore_reipl_open(struct inode *inode, struct file *filp) 148 { 149 return stream_open(inode, filp); 150 } 151 152 static int zcore_reipl_release(struct inode *inode, struct file *filp) 153 { 154 return 0; 155 } 156 157 static const struct file_operations zcore_reipl_fops = { 158 .owner = THIS_MODULE, 159 .write = zcore_reipl_write, 160 .open = zcore_reipl_open, 161 .release = zcore_reipl_release, 162 .llseek = no_llseek, 163 }; 164 165 static ssize_t zcore_hsa_read(struct file *filp, char __user *buf, 166 size_t count, loff_t *ppos) 167 { 168 static char str[18]; 169 170 if (hsa_available) 171 snprintf(str, sizeof(str), "%lx\n", sclp.hsa_size); 172 else 173 snprintf(str, sizeof(str), "0\n"); 174 return simple_read_from_buffer(buf, count, ppos, str, strlen(str)); 175 } 176 177 static ssize_t zcore_hsa_write(struct file *filp, const char __user *buf, 178 size_t count, loff_t *ppos) 179 { 180 char value; 181 182 if (*ppos != 0) 183 return -EPIPE; 184 if (copy_from_user(&value, buf, 1)) 185 return -EFAULT; 186 if (value != '0') 187 return -EINVAL; 188 release_hsa(); 189 return count; 190 } 191 192 static const struct file_operations zcore_hsa_fops = { 193 .owner = THIS_MODULE, 194 .write = zcore_hsa_write, 195 .read = zcore_hsa_read, 196 .open = nonseekable_open, 197 .llseek = no_llseek, 198 }; 199 200 static int __init check_sdias(void) 201 { 202 if (!sclp.hsa_size) { 203 TRACE("Could not determine HSA size\n"); 204 return -ENODEV; 205 } 206 return 0; 207 } 208 209 /* 210 * Provide IPL parameter information block from either HSA or memory 211 * for future reipl 212 */ 213 static int __init zcore_reipl_init(void) 214 { 215 struct ipib_info ipib_info; 216 int rc; 217 218 rc = memcpy_hsa_kernel(&ipib_info, __LC_DUMP_REIPL, sizeof(ipib_info)); 219 if (rc) 220 return rc; 221 if (ipib_info.ipib == 0) 222 return 0; 223 zcore_ipl_block = (void *) __get_free_page(GFP_KERNEL); 224 if (!zcore_ipl_block) 225 return -ENOMEM; 226 if (ipib_info.ipib < sclp.hsa_size) 227 rc = memcpy_hsa_kernel(zcore_ipl_block, ipib_info.ipib, 228 PAGE_SIZE); 229 else 230 rc = memcpy_real(zcore_ipl_block, (void *) ipib_info.ipib, 231 PAGE_SIZE); 232 if (rc || (__force u32)csum_partial(zcore_ipl_block, zcore_ipl_block->hdr.len, 0) != 233 ipib_info.checksum) { 234 TRACE("Checksum does not match\n"); 235 free_page((unsigned long) zcore_ipl_block); 236 zcore_ipl_block = NULL; 237 } 238 return 0; 239 } 240 241 static int __init zcore_init(void) 242 { 243 unsigned char arch; 244 int rc; 245 246 if (!is_ipl_type_dump()) 247 return -ENODATA; 248 if (OLDMEM_BASE) 249 return -ENODATA; 250 251 zcore_dbf = debug_register("zcore", 4, 1, 4 * sizeof(long)); 252 debug_register_view(zcore_dbf, &debug_sprintf_view); 253 debug_set_level(zcore_dbf, 6); 254 255 if (ipl_info.type == IPL_TYPE_FCP_DUMP) { 256 TRACE("type: fcp\n"); 257 TRACE("devno: %x\n", ipl_info.data.fcp.dev_id.devno); 258 TRACE("wwpn: %llx\n", (unsigned long long) ipl_info.data.fcp.wwpn); 259 TRACE("lun: %llx\n", (unsigned long long) ipl_info.data.fcp.lun); 260 } else if (ipl_info.type == IPL_TYPE_NVME_DUMP) { 261 TRACE("type: nvme\n"); 262 TRACE("fid: %x\n", ipl_info.data.nvme.fid); 263 TRACE("nsid: %x\n", ipl_info.data.nvme.nsid); 264 } 265 266 rc = sclp_sdias_init(); 267 if (rc) 268 goto fail; 269 270 rc = check_sdias(); 271 if (rc) 272 goto fail; 273 hsa_available = 1; 274 275 rc = memcpy_hsa_kernel(&arch, __LC_AR_MODE_ID, 1); 276 if (rc) 277 goto fail; 278 279 if (arch == ARCH_S390) { 280 pr_alert("The 64-bit dump tool cannot be used for a " 281 "32-bit system\n"); 282 rc = -EINVAL; 283 goto fail; 284 } 285 286 pr_alert("The dump process started for a 64-bit operating system\n"); 287 rc = init_cpu_info(); 288 if (rc) 289 goto fail; 290 291 rc = zcore_reipl_init(); 292 if (rc) 293 goto fail; 294 295 zcore_dir = debugfs_create_dir("zcore" , NULL); 296 if (!zcore_dir) { 297 rc = -ENOMEM; 298 goto fail; 299 } 300 zcore_reipl_file = debugfs_create_file("reipl", S_IRUSR, zcore_dir, 301 NULL, &zcore_reipl_fops); 302 if (!zcore_reipl_file) { 303 rc = -ENOMEM; 304 goto fail_dir; 305 } 306 zcore_hsa_file = debugfs_create_file("hsa", S_IRUSR|S_IWUSR, zcore_dir, 307 NULL, &zcore_hsa_fops); 308 if (!zcore_hsa_file) { 309 rc = -ENOMEM; 310 goto fail_reipl_file; 311 } 312 return 0; 313 314 fail_reipl_file: 315 debugfs_remove(zcore_reipl_file); 316 fail_dir: 317 debugfs_remove(zcore_dir); 318 fail: 319 diag308(DIAG308_REL_HSA, NULL); 320 return rc; 321 } 322 subsys_initcall(zcore_init); 323