arch/s390/boot/ipl_parm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/kernel.h>
   3 #include <linux/init.h>
   4 #include <linux/ctype.h>
   5 #include <linux/pgtable.h>
   6 #include <asm/page-states.h>
   7 #include <asm/ebcdic.h>
   8 #include <asm/sclp.h>
   9 #include <asm/sections.h>
  10 #include <asm/boot_data.h>
  11 #include <asm/facility.h>
  12 #include <asm/setup.h>
  13 #include <asm/uv.h>
  14 #include "boot.h"
  15
  16 struct parmarea parmarea __section(".parmarea") = {
  17         .kernel_version         = (unsigned long)kernel_version,
  18         .max_command_line_size  = COMMAND_LINE_SIZE,
  19         .command_line           = "root=/dev/ram0 ro",
  20 };
  21
  22 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
  23
  24 unsigned int __bootdata_preserved(zlib_dfltcc_support) = ZLIB_DFLTCC_FULL;
  25 struct ipl_parameter_block __bootdata_preserved(ipl_block);
  26 int __bootdata_preserved(ipl_block_valid);
  27 int __bootdata_preserved(__kaslr_enabled);
  28 int __bootdata_preserved(cmma_flag) = 1;
  29
  30 unsigned long vmalloc_size = VMALLOC_DEFAULT_SIZE;
  31 unsigned long memory_limit;
  32 int vmalloc_size_set;
  33
  34 static inline int __diag308(unsigned long subcode, void *addr)
  35 {
  36         unsigned long reg1, reg2;
  37         union register_pair r1;
  38         psw_t old;
  39
  40         r1.even = (unsigned long) addr;
  41         r1.odd  = 0;
  42         asm volatile(
  43                 "       mvc     0(16,%[psw_old]),0(%[psw_pgm])\n"
  44                 "       epsw    %[reg1],%[reg2]\n"
  45                 "       st      %[reg1],0(%[psw_pgm])\n"
  46                 "       st      %[reg2],4(%[psw_pgm])\n"
  47                 "       larl    %[reg1],1f\n"
  48                 "       stg     %[reg1],8(%[psw_pgm])\n"
  49                 "       diag    %[r1],%[subcode],0x308\n"
  50                 "1:     mvc     0(16,%[psw_pgm]),0(%[psw_old])\n"
  51                 : [r1] "+&d" (r1.pair),
  52                   [reg1] "=&d" (reg1),
  53                   [reg2] "=&a" (reg2),
  54                   "+Q" (S390_lowcore.program_new_psw),
  55                   "=Q" (old)
  56                 : [subcode] "d" (subcode),
  57                   [psw_old] "a" (&old),
  58                   [psw_pgm] "a" (&S390_lowcore.program_new_psw)
  59                 : "cc", "memory");
  60         return r1.odd;
  61 }
  62
  63 void store_ipl_parmblock(void)
  64 {
  65         int rc;
  66
  67         rc = __diag308(DIAG308_STORE, &ipl_block);
  68         if (rc == DIAG308_RC_OK &&
  69             ipl_block.hdr.version <= IPL_MAX_SUPPORTED_VERSION)
  70                 ipl_block_valid = 1;
  71 }
  72
  73 bool is_ipl_block_dump(void)
  74 {
  75         if (ipl_block.pb0_hdr.pbt == IPL_PBT_FCP &&
  76             ipl_block.fcp.opt == IPL_PB0_FCP_OPT_DUMP)
  77                 return true;
  78         if (ipl_block.pb0_hdr.pbt == IPL_PBT_NVME &&
  79             ipl_block.nvme.opt == IPL_PB0_NVME_OPT_DUMP)
  80                 return true;
  81         if (ipl_block.pb0_hdr.pbt == IPL_PBT_ECKD &&
  82             ipl_block.eckd.opt == IPL_PB0_ECKD_OPT_DUMP)
  83                 return true;
  84         return false;
  85 }
  86
  87 static size_t scpdata_length(const u8 *buf, size_t count)
  88 {
  89         while (count) {
  90                 if (buf[count - 1] != '\0' && buf[count - 1] != ' ')
  91                         break;
  92                 count--;
  93         }
  94         return count;
  95 }
  96
  97 static size_t ipl_block_get_ascii_scpdata(char *dest, size_t size,
  98                                           const struct ipl_parameter_block *ipb)
  99 {
 100         const __u8 *scp_data;
 101         __u32 scp_data_len;
 102         int has_lowercase;
 103         size_t count = 0;
 104         size_t i;
 105
 106         switch (ipb->pb0_hdr.pbt) {
 107         case IPL_PBT_FCP:
 108                 scp_data_len = ipb->fcp.scp_data_len;
 109                 scp_data = ipb->fcp.scp_data;
 110                 break;
 111         case IPL_PBT_NVME:
 112                 scp_data_len = ipb->nvme.scp_data_len;
 113                 scp_data = ipb->nvme.scp_data;
 114                 break;
 115         case IPL_PBT_ECKD:
 116                 scp_data_len = ipb->eckd.scp_data_len;
 117                 scp_data = ipb->eckd.scp_data;
 118                 break;
 119
 120         default:
 121                 goto out;
 122         }
 123
 124         count = min(size - 1, scpdata_length(scp_data, scp_data_len));
 125         if (!count)
 126                 goto out;
 127
 128         has_lowercase = 0;
 129         for (i = 0; i < count; i++) {
 130                 if (!isascii(scp_data[i])) {
 131                         count = 0;
 132                         goto out;
 133                 }
 134                 if (!has_lowercase && islower(scp_data[i]))
 135                         has_lowercase = 1;
 136         }
 137
 138         if (has_lowercase)
 139                 memcpy(dest, scp_data, count);
 140         else
 141                 for (i = 0; i < count; i++)
 142                         dest[i] = tolower(scp_data[i]);
 143 out:
 144         dest[count] = '\0';
 145         return count;
 146 }
 147
 148 static void append_ipl_block_parm(void)
 149 {
 150         char *parm, *delim;
 151         size_t len, rc = 0;
 152
 153         len = strlen(early_command_line);
 154
 155         delim = early_command_line + len;    /* '\0' character position */
 156         parm = early_command_line + len + 1; /* append right after '\0' */
 157
 158         switch (ipl_block.pb0_hdr.pbt) {
 159         case IPL_PBT_CCW:
 160                 rc = ipl_block_get_ascii_vmparm(
 161                         parm, COMMAND_LINE_SIZE - len - 1, &ipl_block);
 162                 break;
 163         case IPL_PBT_FCP:
 164         case IPL_PBT_NVME:
 165         case IPL_PBT_ECKD:
 166                 rc = ipl_block_get_ascii_scpdata(
 167                         parm, COMMAND_LINE_SIZE - len - 1, &ipl_block);
 168                 break;
 169         }
 170         if (rc) {
 171                 if (*parm == '=')
 172                         memmove(early_command_line, parm + 1, rc);
 173                 else
 174                         *delim = ' '; /* replace '\0' with space */
 175         }
 176 }
 177
 178 static inline int has_ebcdic_char(const char *str)
 179 {
 180         int i;
 181
 182         for (i = 0; str[i]; i++)
 183                 if (str[i] & 0x80)
 184                         return 1;
 185         return 0;
 186 }
 187
 188 void setup_boot_command_line(void)
 189 {
 190         parmarea.command_line[COMMAND_LINE_SIZE - 1] = 0;
 191         /* convert arch command line to ascii if necessary */
 192         if (has_ebcdic_char(parmarea.command_line))
 193                 EBCASC(parmarea.command_line, COMMAND_LINE_SIZE);
 194         /* copy arch command line */
 195         strcpy(early_command_line, strim(parmarea.command_line));
 196
 197         /* append IPL PARM data to the boot command line */
 198         if (!is_prot_virt_guest() && ipl_block_valid)
 199                 append_ipl_block_parm();
 200 }
 201
 202 static void modify_facility(unsigned long nr, bool clear)
 203 {
 204         if (clear)
 205                 __clear_facility(nr, stfle_fac_list);
 206         else
 207                 __set_facility(nr, stfle_fac_list);
 208 }
 209
 210 static void check_cleared_facilities(void)
 211 {
 212         unsigned long als[] = { FACILITIES_ALS };
 213         int i;
 214
 215         for (i = 0; i < ARRAY_SIZE(als); i++) {
 216                 if ((stfle_fac_list[i] & als[i]) != als[i]) {
 217                         sclp_early_printk("Warning: The Linux kernel requires facilities cleared via command line option\n");
 218                         print_missing_facilities();
 219                         break;
 220                 }
 221         }
 222 }
 223
 224 static void modify_fac_list(char *str)
 225 {
 226         unsigned long val, endval;
 227         char *endp;
 228         bool clear;
 229
 230         while (*str) {
 231                 clear = false;
 232                 if (*str == '!') {
 233                         clear = true;
 234                         str++;
 235                 }
 236                 val = simple_strtoull(str, &endp, 0);
 237                 if (str == endp)
 238                         break;
 239                 str = endp;
 240                 if (*str == '-') {
 241                         str++;
 242                         endval = simple_strtoull(str, &endp, 0);
 243                         if (str == endp)
 244                                 break;
 245                         str = endp;
 246                         while (val <= endval) {
 247                                 modify_facility(val, clear);
 248                                 val++;
 249                         }
 250                 } else {
 251                         modify_facility(val, clear);
 252                 }
 253                 if (*str != ',')
 254                         break;
 255                 str++;
 256         }
 257         check_cleared_facilities();
 258 }
 259
 260 static char command_line_buf[COMMAND_LINE_SIZE];
 261 void parse_boot_command_line(void)
 262 {
 263         char *param, *val;
 264         bool enabled;
 265         char *args;
 266         int rc;
 267
 268         __kaslr_enabled = IS_ENABLED(CONFIG_RANDOMIZE_BASE);
 269         args = strcpy(command_line_buf, early_command_line);
 270         while (*args) {
 271                 args = next_arg(args, &param, &val);
 272
 273                 if (!strcmp(param, "mem") && val)
 274                         memory_limit = round_down(memparse(val, NULL), PAGE_SIZE);
 275
 276                 if (!strcmp(param, "vmalloc") && val) {
 277                         vmalloc_size = round_up(memparse(val, NULL), _SEGMENT_SIZE);
 278                         vmalloc_size_set = 1;
 279                 }
 280
 281                 if (!strcmp(param, "dfltcc") && val) {
 282                         if (!strcmp(val, "off"))
 283                                 zlib_dfltcc_support = ZLIB_DFLTCC_DISABLED;
 284                         else if (!strcmp(val, "on"))
 285                                 zlib_dfltcc_support = ZLIB_DFLTCC_FULL;
 286                         else if (!strcmp(val, "def_only"))
 287                                 zlib_dfltcc_support = ZLIB_DFLTCC_DEFLATE_ONLY;
 288                         else if (!strcmp(val, "inf_only"))
 289                                 zlib_dfltcc_support = ZLIB_DFLTCC_INFLATE_ONLY;
 290                         else if (!strcmp(val, "always"))
 291                                 zlib_dfltcc_support = ZLIB_DFLTCC_FULL_DEBUG;
 292                 }
 293
 294                 if (!strcmp(param, "facilities") && val)
 295                         modify_fac_list(val);
 296
 297                 if (!strcmp(param, "nokaslr"))
 298                         __kaslr_enabled = 0;
 299
 300                 if (!strcmp(param, "cmma")) {
 301                         rc = kstrtobool(val, &enabled);
 302                         if (!rc && !enabled)
 303                                 cmma_flag = 0;
 304                 }
 305
 306 #if IS_ENABLED(CONFIG_KVM)
 307                 if (!strcmp(param, "prot_virt")) {
 308                         rc = kstrtobool(val, &enabled);
 309                         if (!rc && enabled)
 310                                 prot_virt_host = 1;
 311                 }
 312 #endif
 313         }
 314 }