xref: /linux/arch/s390/kernel/early.c (revision 2fe05e1139a555ae91f00a812cb9520e7d3022ab)
1 /*
2  *    Copyright IBM Corp. 2007, 2009
3  *    Author(s): Hongjie Yang <hongjie@us.ibm.com>,
4  *		 Heiko Carstens <heiko.carstens@de.ibm.com>
5  */
6 
7 #define KMSG_COMPONENT "setup"
8 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
9 
10 #include <linux/compiler.h>
11 #include <linux/init.h>
12 #include <linux/errno.h>
13 #include <linux/string.h>
14 #include <linux/ctype.h>
15 #include <linux/lockdep.h>
16 #include <linux/extable.h>
17 #include <linux/pfn.h>
18 #include <linux/uaccess.h>
19 #include <linux/kernel.h>
20 #include <asm/diag.h>
21 #include <asm/ebcdic.h>
22 #include <asm/ipl.h>
23 #include <asm/lowcore.h>
24 #include <asm/processor.h>
25 #include <asm/sections.h>
26 #include <asm/setup.h>
27 #include <asm/sysinfo.h>
28 #include <asm/cpcmd.h>
29 #include <asm/sclp.h>
30 #include <asm/facility.h>
31 #include "entry.h"
32 
33 /*
34  * Create a Kernel NSS if the SAVESYS= parameter is defined
35  */
36 #define DEFSYS_CMD_SIZE		128
37 #define SAVESYS_CMD_SIZE	32
38 
39 char kernel_nss_name[NSS_NAME_SIZE + 1];
40 
41 static void __init setup_boot_command_line(void);
42 
43 /*
44  * Get the TOD clock running.
45  */
46 static void __init reset_tod_clock(void)
47 {
48 	u64 time;
49 
50 	if (store_tod_clock(&time) == 0)
51 		return;
52 	/* TOD clock not running. Set the clock to Unix Epoch. */
53 	if (set_tod_clock(TOD_UNIX_EPOCH) != 0 || store_tod_clock(&time) != 0)
54 		disabled_wait(0);
55 
56 	sched_clock_base_cc = TOD_UNIX_EPOCH;
57 	S390_lowcore.last_update_clock = sched_clock_base_cc;
58 }
59 
60 #ifdef CONFIG_SHARED_KERNEL
61 int __init savesys_ipl_nss(char *cmd, const int cmdlen);
62 
63 asm(
64 	"	.section .init.text,\"ax\",@progbits\n"
65 	"	.align	4\n"
66 	"	.type	savesys_ipl_nss, @function\n"
67 	"savesys_ipl_nss:\n"
68 	"	stmg	6,15,48(15)\n"
69 	"	lgr	14,3\n"
70 	"	sam31\n"
71 	"	diag	2,14,0x8\n"
72 	"	sam64\n"
73 	"	lgr	2,14\n"
74 	"	lmg	6,15,48(15)\n"
75 	"	br	14\n"
76 	"	.size	savesys_ipl_nss, .-savesys_ipl_nss\n"
77 	"	.previous\n");
78 
79 static __initdata char upper_command_line[COMMAND_LINE_SIZE];
80 
81 static noinline __init void create_kernel_nss(void)
82 {
83 	unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
84 #ifdef CONFIG_BLK_DEV_INITRD
85 	unsigned int sinitrd_pfn, einitrd_pfn;
86 #endif
87 	int response;
88 	int hlen;
89 	size_t len;
90 	char *savesys_ptr;
91 	char defsys_cmd[DEFSYS_CMD_SIZE];
92 	char savesys_cmd[SAVESYS_CMD_SIZE];
93 
94 	/* Do nothing if we are not running under VM */
95 	if (!MACHINE_IS_VM)
96 		return;
97 
98 	/* Convert COMMAND_LINE to upper case */
99 	for (i = 0; i < strlen(boot_command_line); i++)
100 		upper_command_line[i] = toupper(boot_command_line[i]);
101 
102 	savesys_ptr = strstr(upper_command_line, "SAVESYS=");
103 
104 	if (!savesys_ptr)
105 		return;
106 
107 	savesys_ptr += 8;    /* Point to the beginning of the NSS name */
108 	for (i = 0; i < NSS_NAME_SIZE; i++) {
109 		if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0')
110 			break;
111 		kernel_nss_name[i] = savesys_ptr[i];
112 	}
113 
114 	stext_pfn = PFN_DOWN(__pa(&_stext));
115 	eshared_pfn = PFN_DOWN(__pa(&_eshared));
116 	end_pfn = PFN_UP(__pa(&_end));
117 	min_size = end_pfn << 2;
118 
119 	hlen = snprintf(defsys_cmd, DEFSYS_CMD_SIZE,
120 			"DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
121 			kernel_nss_name, stext_pfn - 1, stext_pfn,
122 			eshared_pfn - 1, eshared_pfn, end_pfn);
123 
124 #ifdef CONFIG_BLK_DEV_INITRD
125 	if (INITRD_START && INITRD_SIZE) {
126 		sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
127 		einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
128 		min_size = einitrd_pfn << 2;
129 		hlen += snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
130 				 " EW %.5X-%.5X", sinitrd_pfn, einitrd_pfn);
131 	}
132 #endif
133 
134 	snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
135 		 " EW MINSIZE=%.7iK PARMREGS=0-13", min_size);
136 	defsys_cmd[DEFSYS_CMD_SIZE - 1] = '\0';
137 	snprintf(savesys_cmd, SAVESYS_CMD_SIZE, "SAVESYS %s \n IPL %s",
138 		 kernel_nss_name, kernel_nss_name);
139 	savesys_cmd[SAVESYS_CMD_SIZE - 1] = '\0';
140 
141 	__cpcmd(defsys_cmd, NULL, 0, &response);
142 
143 	if (response != 0) {
144 		pr_err("Defining the Linux kernel NSS failed with rc=%d\n",
145 			response);
146 		kernel_nss_name[0] = '\0';
147 		return;
148 	}
149 
150 	len = strlen(savesys_cmd);
151 	ASCEBC(savesys_cmd, len);
152 	response = savesys_ipl_nss(savesys_cmd, len);
153 
154 	/* On success: response is equal to the command size,
155 	 *	       max SAVESYS_CMD_SIZE
156 	 * On error: response contains the numeric portion of cp error message.
157 	 *	     for SAVESYS it will be >= 263
158 	 *	     for missing privilege class, it will be 1
159 	 */
160 	if (response > SAVESYS_CMD_SIZE || response == 1) {
161 		pr_err("Saving the Linux kernel NSS failed with rc=%d\n",
162 			response);
163 		kernel_nss_name[0] = '\0';
164 		return;
165 	}
166 
167 	/* re-initialize cputime accounting. */
168 	sched_clock_base_cc = get_tod_clock();
169 	S390_lowcore.last_update_clock = sched_clock_base_cc;
170 	S390_lowcore.last_update_timer = 0x7fffffffffffffffULL;
171 	S390_lowcore.user_timer = 0;
172 	S390_lowcore.system_timer = 0;
173 	asm volatile("SPT 0(%0)" : : "a" (&S390_lowcore.last_update_timer));
174 
175 	/* re-setup boot command line with new ipl vm parms */
176 	ipl_update_parameters();
177 	setup_boot_command_line();
178 
179 	ipl_flags = IPL_NSS_VALID;
180 }
181 
182 #else /* CONFIG_SHARED_KERNEL */
183 
184 static inline void create_kernel_nss(void) { }
185 
186 #endif /* CONFIG_SHARED_KERNEL */
187 
188 /*
189  * Clear bss memory
190  */
191 static noinline __init void clear_bss_section(void)
192 {
193 	memset(__bss_start, 0, __bss_stop - __bss_start);
194 }
195 
196 /*
197  * Initialize storage key for kernel pages
198  */
199 static noinline __init void init_kernel_storage_key(void)
200 {
201 #if PAGE_DEFAULT_KEY
202 	unsigned long end_pfn, init_pfn;
203 
204 	end_pfn = PFN_UP(__pa(&_end));
205 
206 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
207 		page_set_storage_key(init_pfn << PAGE_SHIFT,
208 				     PAGE_DEFAULT_KEY, 0);
209 #endif
210 }
211 
212 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
213 
214 static noinline __init void detect_machine_type(void)
215 {
216 	struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
217 
218 	/* Check current-configuration-level */
219 	if (stsi(NULL, 0, 0, 0) <= 2) {
220 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
221 		return;
222 	}
223 	/* Get virtual-machine cpu information. */
224 	if (stsi(vmms, 3, 2, 2) || !vmms->count)
225 		return;
226 
227 	/* Running under KVM? If not we assume z/VM */
228 	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
229 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
230 	else
231 		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
232 }
233 
234 /* Remove leading, trailing and double whitespace. */
235 static inline void strim_all(char *str)
236 {
237 	char *s;
238 
239 	s = strim(str);
240 	if (s != str)
241 		memmove(str, s, strlen(s));
242 	while (*str) {
243 		if (!isspace(*str++))
244 			continue;
245 		if (isspace(*str)) {
246 			s = skip_spaces(str);
247 			memmove(str, s, strlen(s) + 1);
248 		}
249 	}
250 }
251 
252 static noinline __init void setup_arch_string(void)
253 {
254 	struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
255 	struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
256 	char mstr[80], hvstr[17];
257 
258 	if (stsi(mach, 1, 1, 1))
259 		return;
260 	EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
261 	EBCASC(mach->type, sizeof(mach->type));
262 	EBCASC(mach->model, sizeof(mach->model));
263 	EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
264 	sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
265 		mach->manufacturer, mach->type,
266 		mach->model, mach->model_capacity);
267 	strim_all(mstr);
268 	if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
269 		EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
270 		sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
271 		strim_all(hvstr);
272 	} else {
273 		sprintf(hvstr, "%s",
274 			MACHINE_IS_LPAR ? "LPAR" :
275 			MACHINE_IS_VM ? "z/VM" :
276 			MACHINE_IS_KVM ? "KVM" : "unknown");
277 	}
278 	dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
279 }
280 
281 static __init void setup_topology(void)
282 {
283 	int max_mnest;
284 
285 	if (!test_facility(11))
286 		return;
287 	S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
288 	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
289 		if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
290 			break;
291 	}
292 	topology_max_mnest = max_mnest;
293 }
294 
295 static void early_pgm_check_handler(void)
296 {
297 	const struct exception_table_entry *fixup;
298 	unsigned long cr0, cr0_new;
299 	unsigned long addr;
300 
301 	addr = S390_lowcore.program_old_psw.addr;
302 	fixup = search_exception_tables(addr);
303 	if (!fixup)
304 		disabled_wait(0);
305 	/* Disable low address protection before storing into lowcore. */
306 	__ctl_store(cr0, 0, 0);
307 	cr0_new = cr0 & ~(1UL << 28);
308 	__ctl_load(cr0_new, 0, 0);
309 	S390_lowcore.program_old_psw.addr = extable_fixup(fixup);
310 	__ctl_load(cr0, 0, 0);
311 }
312 
313 static noinline __init void setup_lowcore_early(void)
314 {
315 	psw_t psw;
316 
317 	psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
318 	psw.addr = (unsigned long) s390_base_ext_handler;
319 	S390_lowcore.external_new_psw = psw;
320 	psw.addr = (unsigned long) s390_base_pgm_handler;
321 	S390_lowcore.program_new_psw = psw;
322 	s390_base_pgm_handler_fn = early_pgm_check_handler;
323 	S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
324 }
325 
326 static noinline __init void setup_facility_list(void)
327 {
328 	stfle(S390_lowcore.stfle_fac_list,
329 	      ARRAY_SIZE(S390_lowcore.stfle_fac_list));
330 }
331 
332 static __init void detect_diag9c(void)
333 {
334 	unsigned int cpu_address;
335 	int rc;
336 
337 	cpu_address = stap();
338 	diag_stat_inc(DIAG_STAT_X09C);
339 	asm volatile(
340 		"	diag	%2,0,0x9c\n"
341 		"0:	la	%0,0\n"
342 		"1:\n"
343 		EX_TABLE(0b,1b)
344 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
345 	if (!rc)
346 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
347 }
348 
349 static __init void detect_diag44(void)
350 {
351 	int rc;
352 
353 	diag_stat_inc(DIAG_STAT_X044);
354 	asm volatile(
355 		"	diag	0,0,0x44\n"
356 		"0:	la	%0,0\n"
357 		"1:\n"
358 		EX_TABLE(0b,1b)
359 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
360 	if (!rc)
361 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
362 }
363 
364 static __init void detect_machine_facilities(void)
365 {
366 	if (test_facility(8)) {
367 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
368 		__ctl_set_bit(0, 23);
369 	}
370 	if (test_facility(78))
371 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
372 	if (test_facility(3))
373 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
374 	if (test_facility(40))
375 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPP;
376 	if (test_facility(50) && test_facility(73))
377 		S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
378 	if (test_facility(51))
379 		S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
380 	if (test_facility(129)) {
381 		S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
382 		__ctl_set_bit(0, 17);
383 	}
384 	if (test_facility(130)) {
385 		S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
386 		__ctl_set_bit(0, 20);
387 	}
388 	if (test_facility(133))
389 		S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
390 }
391 
392 static inline void save_vector_registers(void)
393 {
394 #ifdef CONFIG_CRASH_DUMP
395 	if (test_facility(129))
396 		save_vx_regs(boot_cpu_vector_save_area);
397 #endif
398 }
399 
400 static int __init topology_setup(char *str)
401 {
402 	bool enabled;
403 	int rc;
404 
405 	rc = kstrtobool(str, &enabled);
406 	if (!rc && !enabled)
407 		S390_lowcore.machine_flags &= ~MACHINE_FLAG_TOPOLOGY;
408 	return rc;
409 }
410 early_param("topology", topology_setup);
411 
412 static int __init disable_vector_extension(char *str)
413 {
414 	S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
415 	__ctl_clear_bit(0, 17);
416 	return 1;
417 }
418 early_param("novx", disable_vector_extension);
419 
420 static int __init noexec_setup(char *str)
421 {
422 	bool enabled;
423 	int rc;
424 
425 	rc = kstrtobool(str, &enabled);
426 	if (!rc && !enabled) {
427 		/* Disable no-execute support */
428 		S390_lowcore.machine_flags &= ~MACHINE_FLAG_NX;
429 		__ctl_clear_bit(0, 20);
430 	}
431 	return rc;
432 }
433 early_param("noexec", noexec_setup);
434 
435 static int __init cad_setup(char *str)
436 {
437 	bool enabled;
438 	int rc;
439 
440 	rc = kstrtobool(str, &enabled);
441 	if (!rc && enabled && test_facility(128))
442 		/* Enable problem state CAD. */
443 		__ctl_set_bit(2, 3);
444 	return rc;
445 }
446 early_param("cad", cad_setup);
447 
448 static __init void memmove_early(void *dst, const void *src, size_t n)
449 {
450 	unsigned long addr;
451 	long incr;
452 	psw_t old;
453 
454 	if (!n)
455 		return;
456 	incr = 1;
457 	if (dst > src) {
458 		incr = -incr;
459 		dst += n - 1;
460 		src += n - 1;
461 	}
462 	old = S390_lowcore.program_new_psw;
463 	S390_lowcore.program_new_psw.mask = __extract_psw();
464 	asm volatile(
465 		"	larl	%[addr],1f\n"
466 		"	stg	%[addr],%[psw_pgm_addr]\n"
467 		"0:     mvc	0(1,%[dst]),0(%[src])\n"
468 		"	agr	%[dst],%[incr]\n"
469 		"	agr	%[src],%[incr]\n"
470 		"	brctg	%[n],0b\n"
471 		"1:\n"
472 		: [addr] "=&d" (addr),
473 		  [psw_pgm_addr] "=Q" (S390_lowcore.program_new_psw.addr),
474 		  [dst] "+&a" (dst), [src] "+&a" (src),  [n] "+d" (n)
475 		: [incr] "d" (incr)
476 		: "cc", "memory");
477 	S390_lowcore.program_new_psw = old;
478 }
479 
480 static __init noinline void ipl_save_parameters(void)
481 {
482 	void *src, *dst;
483 
484 	src = (void *)(unsigned long) S390_lowcore.ipl_parmblock_ptr;
485 	dst = (void *) IPL_PARMBLOCK_ORIGIN;
486 	memmove_early(dst, src, PAGE_SIZE);
487 	S390_lowcore.ipl_parmblock_ptr = IPL_PARMBLOCK_ORIGIN;
488 }
489 
490 static __init noinline void rescue_initrd(void)
491 {
492 #ifdef CONFIG_BLK_DEV_INITRD
493 	unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
494 	/*
495 	 * Just like in case of IPL from VM reader we make sure there is a
496 	 * gap of 4MB between end of kernel and start of initrd.
497 	 * That way we can also be sure that saving an NSS will succeed,
498 	 * which however only requires different segments.
499 	 */
500 	if (!INITRD_START || !INITRD_SIZE)
501 		return;
502 	if (INITRD_START >= min_initrd_addr)
503 		return;
504 	memmove_early((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
505 	INITRD_START = min_initrd_addr;
506 #endif
507 }
508 
509 /* Set up boot command line */
510 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
511 {
512 	char *parm, *delim;
513 	size_t rc, len;
514 
515 	len = strlen(boot_command_line);
516 
517 	delim = boot_command_line + len;	/* '\0' character position */
518 	parm  = boot_command_line + len + 1;	/* append right after '\0' */
519 
520 	rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
521 	if (rc) {
522 		if (*parm == '=')
523 			memmove(boot_command_line, parm + 1, rc);
524 		else
525 			*delim = ' ';		/* replace '\0' with space */
526 	}
527 }
528 
529 static inline int has_ebcdic_char(const char *str)
530 {
531 	int i;
532 
533 	for (i = 0; str[i]; i++)
534 		if (str[i] & 0x80)
535 			return 1;
536 	return 0;
537 }
538 
539 static void __init setup_boot_command_line(void)
540 {
541 	COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
542 	/* convert arch command line to ascii if necessary */
543 	if (has_ebcdic_char(COMMAND_LINE))
544 		EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
545 	/* copy arch command line */
546 	strlcpy(boot_command_line, strstrip(COMMAND_LINE),
547 		ARCH_COMMAND_LINE_SIZE);
548 
549 	/* append IPL PARM data to the boot command line */
550 	if (MACHINE_IS_VM)
551 		append_to_cmdline(append_ipl_vmparm);
552 
553 	append_to_cmdline(append_ipl_scpdata);
554 }
555 
556 /*
557  * Save ipl parameters, clear bss memory, initialize storage keys
558  * and create a kernel NSS at startup if the SAVESYS= parm is defined
559  */
560 void __init startup_init(void)
561 {
562 	reset_tod_clock();
563 	ipl_save_parameters();
564 	rescue_initrd();
565 	clear_bss_section();
566 	ipl_verify_parameters();
567 	time_early_init();
568 	init_kernel_storage_key();
569 	lockdep_off();
570 	setup_lowcore_early();
571 	setup_facility_list();
572 	detect_machine_type();
573 	setup_arch_string();
574 	ipl_update_parameters();
575 	setup_boot_command_line();
576 	create_kernel_nss();
577 	detect_diag9c();
578 	detect_diag44();
579 	detect_machine_facilities();
580 	save_vector_registers();
581 	setup_topology();
582 	sclp_early_detect();
583 	lockdep_on();
584 }
585