xref: /openbmc/linux/arch/s390/kernel/early.c (revision 612a462a)
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 	memset(tod_clock_base, 0, 16);
57 	*(__u64 *) &tod_clock_base[1] = TOD_UNIX_EPOCH;
58 	S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
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 	"	stmg	6,15,48(15)\n"
70 	"	lgr	14,3\n"
71 	"	sam31\n"
72 	"	diag	2,14,0x8\n"
73 	"	sam64\n"
74 	"	lgr	2,14\n"
75 	"	lmg	6,15,48(15)\n"
76 	"	br	14\n"
77 	"	.size	savesys_ipl_nss, .-savesys_ipl_nss\n"
78 	"	.previous\n");
79 
80 static __initdata char upper_command_line[COMMAND_LINE_SIZE];
81 
82 static noinline __init void create_kernel_nss(void)
83 {
84 	unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
85 #ifdef CONFIG_BLK_DEV_INITRD
86 	unsigned int sinitrd_pfn, einitrd_pfn;
87 #endif
88 	int response;
89 	int hlen;
90 	size_t len;
91 	char *savesys_ptr;
92 	char defsys_cmd[DEFSYS_CMD_SIZE];
93 	char savesys_cmd[SAVESYS_CMD_SIZE];
94 
95 	/* Do nothing if we are not running under VM */
96 	if (!MACHINE_IS_VM)
97 		return;
98 
99 	/* Convert COMMAND_LINE to upper case */
100 	for (i = 0; i < strlen(boot_command_line); i++)
101 		upper_command_line[i] = toupper(boot_command_line[i]);
102 
103 	savesys_ptr = strstr(upper_command_line, "SAVESYS=");
104 
105 	if (!savesys_ptr)
106 		return;
107 
108 	savesys_ptr += 8;    /* Point to the beginning of the NSS name */
109 	for (i = 0; i < NSS_NAME_SIZE; i++) {
110 		if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0')
111 			break;
112 		kernel_nss_name[i] = savesys_ptr[i];
113 	}
114 
115 	stext_pfn = PFN_DOWN(__pa(&_stext));
116 	eshared_pfn = PFN_DOWN(__pa(&_eshared));
117 	end_pfn = PFN_UP(__pa(&_end));
118 	min_size = end_pfn << 2;
119 
120 	hlen = snprintf(defsys_cmd, DEFSYS_CMD_SIZE,
121 			"DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
122 			kernel_nss_name, stext_pfn - 1, stext_pfn,
123 			eshared_pfn - 1, eshared_pfn, end_pfn);
124 
125 #ifdef CONFIG_BLK_DEV_INITRD
126 	if (INITRD_START && INITRD_SIZE) {
127 		sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
128 		einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
129 		min_size = einitrd_pfn << 2;
130 		hlen += snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
131 				 " EW %.5X-%.5X", sinitrd_pfn, einitrd_pfn);
132 	}
133 #endif
134 
135 	snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
136 		 " EW MINSIZE=%.7iK PARMREGS=0-13", min_size);
137 	defsys_cmd[DEFSYS_CMD_SIZE - 1] = '\0';
138 	snprintf(savesys_cmd, SAVESYS_CMD_SIZE, "SAVESYS %s \n IPL %s",
139 		 kernel_nss_name, kernel_nss_name);
140 	savesys_cmd[SAVESYS_CMD_SIZE - 1] = '\0';
141 
142 	__cpcmd(defsys_cmd, NULL, 0, &response);
143 
144 	if (response != 0) {
145 		pr_err("Defining the Linux kernel NSS failed with rc=%d\n",
146 			response);
147 		kernel_nss_name[0] = '\0';
148 		return;
149 	}
150 
151 	len = strlen(savesys_cmd);
152 	ASCEBC(savesys_cmd, len);
153 	response = savesys_ipl_nss(savesys_cmd, len);
154 
155 	/* On success: response is equal to the command size,
156 	 *	       max SAVESYS_CMD_SIZE
157 	 * On error: response contains the numeric portion of cp error message.
158 	 *	     for SAVESYS it will be >= 263
159 	 *	     for missing privilege class, it will be 1
160 	 */
161 	if (response > SAVESYS_CMD_SIZE || response == 1) {
162 		pr_err("Saving the Linux kernel NSS failed with rc=%d\n",
163 			response);
164 		kernel_nss_name[0] = '\0';
165 		return;
166 	}
167 
168 	/* re-initialize cputime accounting. */
169 	get_tod_clock_ext(tod_clock_base);
170 	S390_lowcore.last_update_clock = *(__u64 *) &tod_clock_base[1];
171 	S390_lowcore.last_update_timer = 0x7fffffffffffffffULL;
172 	S390_lowcore.user_timer = 0;
173 	S390_lowcore.system_timer = 0;
174 	asm volatile("SPT 0(%0)" : : "a" (&S390_lowcore.last_update_timer));
175 
176 	/* re-setup boot command line with new ipl vm parms */
177 	ipl_update_parameters();
178 	setup_boot_command_line();
179 
180 	ipl_flags = IPL_NSS_VALID;
181 }
182 
183 #else /* CONFIG_SHARED_KERNEL */
184 
185 static inline void create_kernel_nss(void) { }
186 
187 #endif /* CONFIG_SHARED_KERNEL */
188 
189 /*
190  * Clear bss memory
191  */
192 static noinline __init void clear_bss_section(void)
193 {
194 	memset(__bss_start, 0, __bss_stop - __bss_start);
195 }
196 
197 /*
198  * Initialize storage key for kernel pages
199  */
200 static noinline __init void init_kernel_storage_key(void)
201 {
202 #if PAGE_DEFAULT_KEY
203 	unsigned long end_pfn, init_pfn;
204 
205 	end_pfn = PFN_UP(__pa(&_end));
206 
207 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
208 		page_set_storage_key(init_pfn << PAGE_SHIFT,
209 				     PAGE_DEFAULT_KEY, 0);
210 #endif
211 }
212 
213 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
214 
215 static noinline __init void detect_machine_type(void)
216 {
217 	struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
218 
219 	/* Check current-configuration-level */
220 	if (stsi(NULL, 0, 0, 0) <= 2) {
221 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
222 		return;
223 	}
224 	/* Get virtual-machine cpu information. */
225 	if (stsi(vmms, 3, 2, 2) || !vmms->count)
226 		return;
227 
228 	/* Running under KVM? If not we assume z/VM */
229 	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
230 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
231 	else
232 		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
233 }
234 
235 /* Remove leading, trailing and double whitespace. */
236 static inline void strim_all(char *str)
237 {
238 	char *s;
239 
240 	s = strim(str);
241 	if (s != str)
242 		memmove(str, s, strlen(s));
243 	while (*str) {
244 		if (!isspace(*str++))
245 			continue;
246 		if (isspace(*str)) {
247 			s = skip_spaces(str);
248 			memmove(str, s, strlen(s) + 1);
249 		}
250 	}
251 }
252 
253 static noinline __init void setup_arch_string(void)
254 {
255 	struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
256 	struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
257 	char mstr[80], hvstr[17];
258 
259 	if (stsi(mach, 1, 1, 1))
260 		return;
261 	EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
262 	EBCASC(mach->type, sizeof(mach->type));
263 	EBCASC(mach->model, sizeof(mach->model));
264 	EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
265 	sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
266 		mach->manufacturer, mach->type,
267 		mach->model, mach->model_capacity);
268 	strim_all(mstr);
269 	if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
270 		EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
271 		sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
272 		strim_all(hvstr);
273 	} else {
274 		sprintf(hvstr, "%s",
275 			MACHINE_IS_LPAR ? "LPAR" :
276 			MACHINE_IS_VM ? "z/VM" :
277 			MACHINE_IS_KVM ? "KVM" : "unknown");
278 	}
279 	dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
280 }
281 
282 static __init void setup_topology(void)
283 {
284 	int max_mnest;
285 
286 	if (!test_facility(11))
287 		return;
288 	S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
289 	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
290 		if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
291 			break;
292 	}
293 	topology_max_mnest = max_mnest;
294 }
295 
296 static void early_pgm_check_handler(void)
297 {
298 	const struct exception_table_entry *fixup;
299 	unsigned long cr0, cr0_new;
300 	unsigned long addr;
301 
302 	addr = S390_lowcore.program_old_psw.addr;
303 	fixup = search_exception_tables(addr);
304 	if (!fixup)
305 		disabled_wait(0);
306 	/* Disable low address protection before storing into lowcore. */
307 	__ctl_store(cr0, 0, 0);
308 	cr0_new = cr0 & ~(1UL << 28);
309 	__ctl_load(cr0_new, 0, 0);
310 	S390_lowcore.program_old_psw.addr = extable_fixup(fixup);
311 	__ctl_load(cr0, 0, 0);
312 }
313 
314 static noinline __init void setup_lowcore_early(void)
315 {
316 	psw_t psw;
317 
318 	psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
319 	psw.addr = (unsigned long) s390_base_ext_handler;
320 	S390_lowcore.external_new_psw = psw;
321 	psw.addr = (unsigned long) s390_base_pgm_handler;
322 	S390_lowcore.program_new_psw = psw;
323 	s390_base_pgm_handler_fn = early_pgm_check_handler;
324 	S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
325 }
326 
327 static noinline __init void setup_facility_list(void)
328 {
329 	stfle(S390_lowcore.stfle_fac_list,
330 	      ARRAY_SIZE(S390_lowcore.stfle_fac_list));
331 }
332 
333 static __init void detect_diag9c(void)
334 {
335 	unsigned int cpu_address;
336 	int rc;
337 
338 	cpu_address = stap();
339 	diag_stat_inc(DIAG_STAT_X09C);
340 	asm volatile(
341 		"	diag	%2,0,0x9c\n"
342 		"0:	la	%0,0\n"
343 		"1:\n"
344 		EX_TABLE(0b,1b)
345 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
346 	if (!rc)
347 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
348 }
349 
350 static __init void detect_diag44(void)
351 {
352 	int rc;
353 
354 	diag_stat_inc(DIAG_STAT_X044);
355 	asm volatile(
356 		"	diag	0,0,0x44\n"
357 		"0:	la	%0,0\n"
358 		"1:\n"
359 		EX_TABLE(0b,1b)
360 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
361 	if (!rc)
362 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
363 }
364 
365 static __init void detect_machine_facilities(void)
366 {
367 	if (test_facility(8)) {
368 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
369 		__ctl_set_bit(0, 23);
370 	}
371 	if (test_facility(78))
372 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
373 	if (test_facility(3))
374 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
375 	if (test_facility(40))
376 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPP;
377 	if (test_facility(50) && test_facility(73))
378 		S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
379 	if (test_facility(51))
380 		S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
381 	if (test_facility(129)) {
382 		S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
383 		__ctl_set_bit(0, 17);
384 	}
385 	if (test_facility(130)) {
386 		S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
387 		__ctl_set_bit(0, 20);
388 	}
389 	if (test_facility(133))
390 		S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
391 	if (test_facility(139) && (tod_clock_base[1] & 0x80)) {
392 		/* Enabled signed clock comparator comparisons */
393 		S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
394 		clock_comparator_max = -1ULL >> 1;
395 		__ctl_set_bit(0, 53);
396 	}
397 }
398 
399 static inline void save_vector_registers(void)
400 {
401 #ifdef CONFIG_CRASH_DUMP
402 	if (test_facility(129))
403 		save_vx_regs(boot_cpu_vector_save_area);
404 #endif
405 }
406 
407 static int __init disable_vector_extension(char *str)
408 {
409 	S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
410 	__ctl_clear_bit(0, 17);
411 	return 0;
412 }
413 early_param("novx", disable_vector_extension);
414 
415 static int __init noexec_setup(char *str)
416 {
417 	bool enabled;
418 	int rc;
419 
420 	rc = kstrtobool(str, &enabled);
421 	if (!rc && !enabled) {
422 		/* Disable no-execute support */
423 		S390_lowcore.machine_flags &= ~MACHINE_FLAG_NX;
424 		__ctl_clear_bit(0, 20);
425 	}
426 	return rc;
427 }
428 early_param("noexec", noexec_setup);
429 
430 static int __init cad_setup(char *str)
431 {
432 	bool enabled;
433 	int rc;
434 
435 	rc = kstrtobool(str, &enabled);
436 	if (!rc && enabled && test_facility(128))
437 		/* Enable problem state CAD. */
438 		__ctl_set_bit(2, 3);
439 	return rc;
440 }
441 early_param("cad", cad_setup);
442 
443 static __init void memmove_early(void *dst, const void *src, size_t n)
444 {
445 	unsigned long addr;
446 	long incr;
447 	psw_t old;
448 
449 	if (!n)
450 		return;
451 	incr = 1;
452 	if (dst > src) {
453 		incr = -incr;
454 		dst += n - 1;
455 		src += n - 1;
456 	}
457 	old = S390_lowcore.program_new_psw;
458 	S390_lowcore.program_new_psw.mask = __extract_psw();
459 	asm volatile(
460 		"	larl	%[addr],1f\n"
461 		"	stg	%[addr],%[psw_pgm_addr]\n"
462 		"0:     mvc	0(1,%[dst]),0(%[src])\n"
463 		"	agr	%[dst],%[incr]\n"
464 		"	agr	%[src],%[incr]\n"
465 		"	brctg	%[n],0b\n"
466 		"1:\n"
467 		: [addr] "=&d" (addr),
468 		  [psw_pgm_addr] "=Q" (S390_lowcore.program_new_psw.addr),
469 		  [dst] "+&a" (dst), [src] "+&a" (src),  [n] "+d" (n)
470 		: [incr] "d" (incr)
471 		: "cc", "memory");
472 	S390_lowcore.program_new_psw = old;
473 }
474 
475 static __init noinline void ipl_save_parameters(void)
476 {
477 	void *src, *dst;
478 
479 	src = (void *)(unsigned long) S390_lowcore.ipl_parmblock_ptr;
480 	dst = (void *) IPL_PARMBLOCK_ORIGIN;
481 	memmove_early(dst, src, PAGE_SIZE);
482 	S390_lowcore.ipl_parmblock_ptr = IPL_PARMBLOCK_ORIGIN;
483 }
484 
485 static __init noinline void rescue_initrd(void)
486 {
487 #ifdef CONFIG_BLK_DEV_INITRD
488 	unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
489 	/*
490 	 * Just like in case of IPL from VM reader we make sure there is a
491 	 * gap of 4MB between end of kernel and start of initrd.
492 	 * That way we can also be sure that saving an NSS will succeed,
493 	 * which however only requires different segments.
494 	 */
495 	if (!INITRD_START || !INITRD_SIZE)
496 		return;
497 	if (INITRD_START >= min_initrd_addr)
498 		return;
499 	memmove_early((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
500 	INITRD_START = min_initrd_addr;
501 #endif
502 }
503 
504 /* Set up boot command line */
505 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
506 {
507 	char *parm, *delim;
508 	size_t rc, len;
509 
510 	len = strlen(boot_command_line);
511 
512 	delim = boot_command_line + len;	/* '\0' character position */
513 	parm  = boot_command_line + len + 1;	/* append right after '\0' */
514 
515 	rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
516 	if (rc) {
517 		if (*parm == '=')
518 			memmove(boot_command_line, parm + 1, rc);
519 		else
520 			*delim = ' ';		/* replace '\0' with space */
521 	}
522 }
523 
524 static inline int has_ebcdic_char(const char *str)
525 {
526 	int i;
527 
528 	for (i = 0; str[i]; i++)
529 		if (str[i] & 0x80)
530 			return 1;
531 	return 0;
532 }
533 
534 static void __init setup_boot_command_line(void)
535 {
536 	COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
537 	/* convert arch command line to ascii if necessary */
538 	if (has_ebcdic_char(COMMAND_LINE))
539 		EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
540 	/* copy arch command line */
541 	strlcpy(boot_command_line, strstrip(COMMAND_LINE),
542 		ARCH_COMMAND_LINE_SIZE);
543 
544 	/* append IPL PARM data to the boot command line */
545 	if (MACHINE_IS_VM)
546 		append_to_cmdline(append_ipl_vmparm);
547 
548 	append_to_cmdline(append_ipl_scpdata);
549 }
550 
551 /*
552  * Save ipl parameters, clear bss memory, initialize storage keys
553  * and create a kernel NSS at startup if the SAVESYS= parm is defined
554  */
555 void __init startup_init(void)
556 {
557 	reset_tod_clock();
558 	ipl_save_parameters();
559 	rescue_initrd();
560 	clear_bss_section();
561 	ipl_verify_parameters();
562 	time_early_init();
563 	init_kernel_storage_key();
564 	lockdep_off();
565 	setup_lowcore_early();
566 	setup_facility_list();
567 	detect_machine_type();
568 	setup_arch_string();
569 	ipl_update_parameters();
570 	setup_boot_command_line();
571 	create_kernel_nss();
572 	detect_diag9c();
573 	detect_diag44();
574 	detect_machine_facilities();
575 	save_vector_registers();
576 	setup_topology();
577 	sclp_early_detect();
578 	lockdep_on();
579 }
580