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Avoid beyond bounds copy while caching ACL
[zen-stable.git] / arch / s390 / kernel / early.c
blob52098d6dfaa71dabed19f287aaa225672aba6c55
1 /*
2 * arch/s390/kernel/early.c
3 *
4 * Copyright IBM Corp. 2007, 2009
5 * Author(s): Hongjie Yang <hongjie@us.ibm.com>,
6 * Heiko Carstens <heiko.carstens@de.ibm.com>
7 */
8
9 #define KMSG_COMPONENT "setup"
10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
11
12 #include <linux/compiler.h>
13 #include <linux/init.h>
14 #include <linux/errno.h>
15 #include <linux/string.h>
16 #include <linux/ctype.h>
17 #include <linux/ftrace.h>
18 #include <linux/lockdep.h>
19 #include <linux/module.h>
20 #include <linux/pfn.h>
21 #include <linux/uaccess.h>
22 #include <linux/kernel.h>
23 #include <asm/ebcdic.h>
24 #include <asm/ipl.h>
25 #include <asm/lowcore.h>
26 #include <asm/processor.h>
27 #include <asm/sections.h>
28 #include <asm/setup.h>
29 #include <asm/sysinfo.h>
30 #include <asm/cpcmd.h>
31 #include <asm/sclp.h>
32 #include "entry.h"
33
34 /*
35 * Create a Kernel NSS if the SAVESYS= parameter is defined
36 */
37 #define DEFSYS_CMD_SIZE 128
38 #define SAVESYS_CMD_SIZE 32
39
40 char kernel_nss_name[NSS_NAME_SIZE + 1];
41
42 static void __init setup_boot_command_line(void);
43
44 /*
45 * Get the TOD clock running.
46 */
47 static void __init reset_tod_clock(void)
48 {
49 u64 time;
50
51 if (store_clock(&time) == 0)
52 return;
53 /* TOD clock not running. Set the clock to Unix Epoch. */
54 if (set_clock(TOD_UNIX_EPOCH) != 0 || store_clock(&time) != 0)
55 disabled_wait(0);
56
57 sched_clock_base_cc = TOD_UNIX_EPOCH;
58 S390_lowcore.last_update_clock = sched_clock_base_cc;
59 }
60
61 #ifdef CONFIG_SHARED_KERNEL
62 int __init savesys_ipl_nss(char *cmd, const int cmdlen);
63
64 asm(
65 " .section .init.text,\"ax\",@progbits\n"
66 " .align 4\n"
67 " .type savesys_ipl_nss, @function\n"
68 "savesys_ipl_nss:\n"
69 #ifdef CONFIG_64BIT
70 " stmg 6,15,48(15)\n"
71 " lgr 14,3\n"
72 " sam31\n"
73 " diag 2,14,0x8\n"
74 " sam64\n"
75 " lgr 2,14\n"
76 " lmg 6,15,48(15)\n"
77 #else
78 " stm 6,15,24(15)\n"
79 " lr 14,3\n"
80 " diag 2,14,0x8\n"
81 " lr 2,14\n"
82 " lm 6,15,24(15)\n"
83 #endif
84 " br 14\n"
85 " .size savesys_ipl_nss, .-savesys_ipl_nss\n"
86 " .previous\n");
87
88 static __initdata char upper_command_line[COMMAND_LINE_SIZE];
89
90 static noinline __init void create_kernel_nss(void)
91 {
92 unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
93 #ifdef CONFIG_BLK_DEV_INITRD
94 unsigned int sinitrd_pfn, einitrd_pfn;
95 #endif
96 int response;
97 int hlen;
98 size_t len;
99 char *savesys_ptr;
100 char defsys_cmd[DEFSYS_CMD_SIZE];
101 char savesys_cmd[SAVESYS_CMD_SIZE];
102
103 /* Do nothing if we are not running under VM */
104 if (!MACHINE_IS_VM)
105 return;
106
107 /* Convert COMMAND_LINE to upper case */
108 for (i = 0; i < strlen(boot_command_line); i++)
109 upper_command_line[i] = toupper(boot_command_line[i]);
110
111 savesys_ptr = strstr(upper_command_line, "SAVESYS=");
112
113 if (!savesys_ptr)
114 return;
115
116 savesys_ptr += 8; /* Point to the beginning of the NSS name */
117 for (i = 0; i < NSS_NAME_SIZE; i++) {
118 if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0')
119 break;
120 kernel_nss_name[i] = savesys_ptr[i];
121 }
122
123 stext_pfn = PFN_DOWN(__pa(&_stext));
124 eshared_pfn = PFN_DOWN(__pa(&_eshared));
125 end_pfn = PFN_UP(__pa(&_end));
126 min_size = end_pfn << 2;
127
128 hlen = snprintf(defsys_cmd, DEFSYS_CMD_SIZE,
129 "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
130 kernel_nss_name, stext_pfn - 1, stext_pfn,
131 eshared_pfn - 1, eshared_pfn, end_pfn);
132
133 #ifdef CONFIG_BLK_DEV_INITRD
134 if (INITRD_START && INITRD_SIZE) {
135 sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
136 einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
137 min_size = einitrd_pfn << 2;
138 hlen += snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
139 " EW %.5X-%.5X", sinitrd_pfn, einitrd_pfn);
140 }
141 #endif
142
143 snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
144 " EW MINSIZE=%.7iK PARMREGS=0-13", min_size);
145 defsys_cmd[DEFSYS_CMD_SIZE - 1] = '\0';
146 snprintf(savesys_cmd, SAVESYS_CMD_SIZE, "SAVESYS %s \n IPL %s",
147 kernel_nss_name, kernel_nss_name);
148 savesys_cmd[SAVESYS_CMD_SIZE - 1] = '\0';
149
150 __cpcmd(defsys_cmd, NULL, 0, &response);
151
152 if (response != 0) {
153 pr_err("Defining the Linux kernel NSS failed with rc=%d\n",
154 response);
155 kernel_nss_name[0] = '\0';
156 return;
157 }
158
159 len = strlen(savesys_cmd);
160 ASCEBC(savesys_cmd, len);
161 response = savesys_ipl_nss(savesys_cmd, len);
162
163 /* On success: response is equal to the command size,
164 * max SAVESYS_CMD_SIZE
165 * On error: response contains the numeric portion of cp error message.
166 * for SAVESYS it will be >= 263
167 * for missing privilege class, it will be 1
168 */
169 if (response > SAVESYS_CMD_SIZE || response == 1) {
170 pr_err("Saving the Linux kernel NSS failed with rc=%d\n",
171 response);
172 kernel_nss_name[0] = '\0';
173 return;
174 }
175
176 /* re-initialize cputime accounting. */
177 sched_clock_base_cc = get_clock();
178 S390_lowcore.last_update_clock = sched_clock_base_cc;
179 S390_lowcore.last_update_timer = 0x7fffffffffffffffULL;
180 S390_lowcore.user_timer = 0;
181 S390_lowcore.system_timer = 0;
182 asm volatile("SPT 0(%0)" : : "a" (&S390_lowcore.last_update_timer));
183
184 /* re-setup boot command line with new ipl vm parms */
185 ipl_update_parameters();
186 setup_boot_command_line();
187
188 ipl_flags = IPL_NSS_VALID;
189 }
190
191 #else /* CONFIG_SHARED_KERNEL */
192
193 static inline void create_kernel_nss(void) { }
194
195 #endif /* CONFIG_SHARED_KERNEL */
196
197 /*
198 * Clear bss memory
199 */
200 static noinline __init void clear_bss_section(void)
201 {
202 memset(__bss_start, 0, __bss_stop - __bss_start);
203 }
204
205 /*
206 * Initialize storage key for kernel pages
207 */
208 static noinline __init void init_kernel_storage_key(void)
209 {
210 unsigned long end_pfn, init_pfn;
211
212 end_pfn = PFN_UP(__pa(&_end));
213
214 for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
215 page_set_storage_key(init_pfn << PAGE_SHIFT,
216 PAGE_DEFAULT_KEY, 0);
217 }
218
219 static __initdata struct sysinfo_3_2_2 vmms __aligned(PAGE_SIZE);
220
221 static noinline __init void detect_machine_type(void)
222 {
223 /* Check current-configuration-level */
224 if ((stsi(NULL, 0, 0, 0) >> 28) <= 2) {
225 S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
226 return;
227 }
228 /* Get virtual-machine cpu information. */
229 if (stsi(&vmms, 3, 2, 2) == -ENOSYS || !vmms.count)
230 return;
231
232 /* Running under KVM? If not we assume z/VM */
233 if (!memcmp(vmms.vm[0].cpi, "\xd2\xe5\xd4", 3))
234 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
235 else
236 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
237 }
238
239 static __init void early_pgm_check_handler(void)
240 {
241 unsigned long addr;
242 const struct exception_table_entry *fixup;
243
244 addr = S390_lowcore.program_old_psw.addr;
245 fixup = search_exception_tables(addr & PSW_ADDR_INSN);
246 if (!fixup)
247 disabled_wait(0);
248 S390_lowcore.program_old_psw.addr = fixup->fixup | PSW_ADDR_AMODE;
249 }
250
251 static noinline __init void setup_lowcore_early(void)
252 {
253 psw_t psw;
254
255 psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
256 psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
257 S390_lowcore.external_new_psw = psw;
258 psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
259 S390_lowcore.program_new_psw = psw;
260 s390_base_pgm_handler_fn = early_pgm_check_handler;
261 }
262
263 static noinline __init void setup_facility_list(void)
264 {
265 unsigned long nr;
266
267 S390_lowcore.stfl_fac_list = 0;
268 asm volatile(
269 " .insn s,0xb2b10000,0(0)\n" /* stfl */
270 "0:\n"
271 EX_TABLE(0b,0b) : "=m" (S390_lowcore.stfl_fac_list));
272 memcpy(&S390_lowcore.stfle_fac_list, &S390_lowcore.stfl_fac_list, 4);
273 nr = 4; /* # bytes stored by stfl */
274 if (test_facility(7)) {
275 /* More facility bits available with stfle */
276 register unsigned long reg0 asm("0") = MAX_FACILITY_BIT/64 - 1;
277 asm volatile(".insn s,0xb2b00000,%0" /* stfle */
278 : "=m" (S390_lowcore.stfle_fac_list), "+d" (reg0)
279 : : "cc");
280 nr = (reg0 + 1) * 8; /* # bytes stored by stfle */
281 }
282 memset((char *) S390_lowcore.stfle_fac_list + nr, 0,
283 MAX_FACILITY_BIT/8 - nr);
284 }
285
286 static noinline __init void setup_hpage(void)
287 {
288 #ifndef CONFIG_DEBUG_PAGEALLOC
289 if (!test_facility(2) || !test_facility(8))
290 return;
291 S390_lowcore.machine_flags |= MACHINE_FLAG_HPAGE;
292 __ctl_set_bit(0, 23);
293 #endif
294 }
295
296 static __init void detect_mvpg(void)
297 {
298 #ifndef CONFIG_64BIT
299 int rc;
300
301 asm volatile(
302 " la 0,0\n"
303 " mvpg %2,%2\n"
304 "0: la %0,0\n"
305 "1:\n"
306 EX_TABLE(0b,1b)
307 : "=d" (rc) : "0" (-EOPNOTSUPP), "a" (0) : "memory", "cc", "0");
308 if (!rc)
309 S390_lowcore.machine_flags |= MACHINE_FLAG_MVPG;
310 #endif
311 }
312
313 static __init void detect_ieee(void)
314 {
315 #ifndef CONFIG_64BIT
316 int rc, tmp;
317
318 asm volatile(
319 " efpc %1,0\n"
320 "0: la %0,0\n"
321 "1:\n"
322 EX_TABLE(0b,1b)
323 : "=d" (rc), "=d" (tmp): "0" (-EOPNOTSUPP) : "cc");
324 if (!rc)
325 S390_lowcore.machine_flags |= MACHINE_FLAG_IEEE;
326 #endif
327 }
328
329 static __init void detect_csp(void)
330 {
331 #ifndef CONFIG_64BIT
332 int rc;
333
334 asm volatile(
335 " la 0,0\n"
336 " la 1,0\n"
337 " la 2,4\n"
338 " csp 0,2\n"
339 "0: la %0,0\n"
340 "1:\n"
341 EX_TABLE(0b,1b)
342 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc", "0", "1", "2");
343 if (!rc)
344 S390_lowcore.machine_flags |= MACHINE_FLAG_CSP;
345 #endif
346 }
347
348 static __init void detect_diag9c(void)
349 {
350 unsigned int cpu_address;
351 int rc;
352
353 cpu_address = stap();
354 asm volatile(
355 " diag %2,0,0x9c\n"
356 "0: la %0,0\n"
357 "1:\n"
358 EX_TABLE(0b,1b)
359 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
360 if (!rc)
361 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
362 }
363
364 static __init void detect_diag44(void)
365 {
366 #ifdef CONFIG_64BIT
367 int rc;
368
369 asm volatile(
370 " diag 0,0,0x44\n"
371 "0: la %0,0\n"
372 "1:\n"
373 EX_TABLE(0b,1b)
374 : "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
375 if (!rc)
376 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
377 #endif
378 }
379
380 static __init void detect_machine_facilities(void)
381 {
382 #ifdef CONFIG_64BIT
383 if (test_facility(3))
384 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
385 if (test_facility(8))
386 S390_lowcore.machine_flags |= MACHINE_FLAG_PFMF;
387 if (test_facility(11))
388 S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
389 if (test_facility(27))
390 S390_lowcore.machine_flags |= MACHINE_FLAG_MVCOS;
391 if (test_facility(40))
392 S390_lowcore.machine_flags |= MACHINE_FLAG_SPP;
393 if (test_facility(25))
394 S390_lowcore.machine_flags |= MACHINE_FLAG_STCKF;
395 #endif
396 }
397
398 static __init void rescue_initrd(void)
399 {
400 #ifdef CONFIG_BLK_DEV_INITRD
401 unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
402 /*
403 * Just like in case of IPL from VM reader we make sure there is a
404 * gap of 4MB between end of kernel and start of initrd.
405 * That way we can also be sure that saving an NSS will succeed,
406 * which however only requires different segments.
407 */
408 if (!INITRD_START || !INITRD_SIZE)
409 return;
410 if (INITRD_START >= min_initrd_addr)
411 return;
412 memmove((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
413 INITRD_START = min_initrd_addr;
414 #endif
415 }
416
417 /* Set up boot command line */
418 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
419 {
420 char *parm, *delim;
421 size_t rc, len;
422
423 len = strlen(boot_command_line);
424
425 delim = boot_command_line + len; /* '\0' character position */
426 parm = boot_command_line + len + 1; /* append right after '\0' */
427
428 rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
429 if (rc) {
430 if (*parm == '=')
431 memmove(boot_command_line, parm + 1, rc);
432 else
433 *delim = ' '; /* replace '\0' with space */
434 }
435 }
436
437 static inline int has_ebcdic_char(const char *str)
438 {
439 int i;
440
441 for (i = 0; str[i]; i++)
442 if (str[i] & 0x80)
443 return 1;
444 return 0;
445 }
446
447 static void __init setup_boot_command_line(void)
448 {
449 COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
450 /* convert arch command line to ascii if necessary */
451 if (has_ebcdic_char(COMMAND_LINE))
452 EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
453 /* copy arch command line */
454 strlcpy(boot_command_line, strstrip(COMMAND_LINE),
455 ARCH_COMMAND_LINE_SIZE);
456
457 /* append IPL PARM data to the boot command line */
458 if (MACHINE_IS_VM)
459 append_to_cmdline(append_ipl_vmparm);
460
461 append_to_cmdline(append_ipl_scpdata);
462 }
463
464
465 /*
466 * Save ipl parameters, clear bss memory, initialize storage keys
467 * and create a kernel NSS at startup if the SAVESYS= parm is defined
468 */
469 void __init startup_init(void)
470 {
471 reset_tod_clock();
472 ipl_save_parameters();
473 rescue_initrd();
474 clear_bss_section();
475 init_kernel_storage_key();
476 lockdep_init();
477 lockdep_off();
478 sort_main_extable();
479 setup_lowcore_early();
480 setup_facility_list();
481 detect_machine_type();
482 ipl_update_parameters();
483 setup_boot_command_line();
484 create_kernel_nss();
485 detect_mvpg();
486 detect_ieee();
487 detect_csp();
488 detect_diag9c();
489 detect_diag44();
490 detect_machine_facilities();
491 setup_hpage();
492 sclp_facilities_detect();
493 detect_memory_layout(memory_chunk);
494 #ifdef CONFIG_DYNAMIC_FTRACE
495 S390_lowcore.ftrace_func = (unsigned long)ftrace_caller;
496 #endif
497 lockdep_on();
498 }