xref: /openbmc/linux/arch/s390/kernel/early.c (revision e3b9f1e8)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *    Copyright IBM Corp. 2007, 2009
4  *    Author(s): Hongjie Yang <hongjie@us.ibm.com>,
5  *		 Heiko Carstens <heiko.carstens@de.ibm.com>
6  */
7 
8 #define KMSG_COMPONENT "setup"
9 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
10 
11 #include <linux/compiler.h>
12 #include <linux/init.h>
13 #include <linux/errno.h>
14 #include <linux/string.h>
15 #include <linux/ctype.h>
16 #include <linux/lockdep.h>
17 #include <linux/extable.h>
18 #include <linux/pfn.h>
19 #include <linux/uaccess.h>
20 #include <linux/kernel.h>
21 #include <asm/diag.h>
22 #include <asm/ebcdic.h>
23 #include <asm/ipl.h>
24 #include <asm/lowcore.h>
25 #include <asm/processor.h>
26 #include <asm/sections.h>
27 #include <asm/setup.h>
28 #include <asm/sysinfo.h>
29 #include <asm/cpcmd.h>
30 #include <asm/sclp.h>
31 #include <asm/facility.h>
32 #include "entry.h"
33 
34 static void __init setup_boot_command_line(void);
35 
36 /*
37  * Get the TOD clock running.
38  */
39 static void __init reset_tod_clock(void)
40 {
41 	u64 time;
42 
43 	if (store_tod_clock(&time) == 0)
44 		return;
45 	/* TOD clock not running. Set the clock to Unix Epoch. */
46 	if (set_tod_clock(TOD_UNIX_EPOCH) != 0 || store_tod_clock(&time) != 0)
47 		disabled_wait(0);
48 
49 	memset(tod_clock_base, 0, 16);
50 	*(__u64 *) &tod_clock_base[1] = TOD_UNIX_EPOCH;
51 	S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
52 }
53 
54 /*
55  * Clear bss memory
56  */
57 static noinline __init void clear_bss_section(void)
58 {
59 	memset(__bss_start, 0, __bss_stop - __bss_start);
60 }
61 
62 /*
63  * Initialize storage key for kernel pages
64  */
65 static noinline __init void init_kernel_storage_key(void)
66 {
67 #if PAGE_DEFAULT_KEY
68 	unsigned long end_pfn, init_pfn;
69 
70 	end_pfn = PFN_UP(__pa(&_end));
71 
72 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
73 		page_set_storage_key(init_pfn << PAGE_SHIFT,
74 				     PAGE_DEFAULT_KEY, 0);
75 #endif
76 }
77 
78 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
79 
80 static noinline __init void detect_machine_type(void)
81 {
82 	struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
83 
84 	/* Check current-configuration-level */
85 	if (stsi(NULL, 0, 0, 0) <= 2) {
86 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
87 		return;
88 	}
89 	/* Get virtual-machine cpu information. */
90 	if (stsi(vmms, 3, 2, 2) || !vmms->count)
91 		return;
92 
93 	/* Running under KVM? If not we assume z/VM */
94 	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
95 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
96 	else
97 		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
98 }
99 
100 /* Remove leading, trailing and double whitespace. */
101 static inline void strim_all(char *str)
102 {
103 	char *s;
104 
105 	s = strim(str);
106 	if (s != str)
107 		memmove(str, s, strlen(s));
108 	while (*str) {
109 		if (!isspace(*str++))
110 			continue;
111 		if (isspace(*str)) {
112 			s = skip_spaces(str);
113 			memmove(str, s, strlen(s) + 1);
114 		}
115 	}
116 }
117 
118 static noinline __init void setup_arch_string(void)
119 {
120 	struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
121 	struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
122 	char mstr[80], hvstr[17];
123 
124 	if (stsi(mach, 1, 1, 1))
125 		return;
126 	EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
127 	EBCASC(mach->type, sizeof(mach->type));
128 	EBCASC(mach->model, sizeof(mach->model));
129 	EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
130 	sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
131 		mach->manufacturer, mach->type,
132 		mach->model, mach->model_capacity);
133 	strim_all(mstr);
134 	if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
135 		EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
136 		sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
137 		strim_all(hvstr);
138 	} else {
139 		sprintf(hvstr, "%s",
140 			MACHINE_IS_LPAR ? "LPAR" :
141 			MACHINE_IS_VM ? "z/VM" :
142 			MACHINE_IS_KVM ? "KVM" : "unknown");
143 	}
144 	dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
145 }
146 
147 static __init void setup_topology(void)
148 {
149 	int max_mnest;
150 
151 	if (!test_facility(11))
152 		return;
153 	S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
154 	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
155 		if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
156 			break;
157 	}
158 	topology_max_mnest = max_mnest;
159 }
160 
161 static void early_pgm_check_handler(void)
162 {
163 	const struct exception_table_entry *fixup;
164 	unsigned long cr0, cr0_new;
165 	unsigned long addr;
166 
167 	addr = S390_lowcore.program_old_psw.addr;
168 	fixup = search_exception_tables(addr);
169 	if (!fixup)
170 		disabled_wait(0);
171 	/* Disable low address protection before storing into lowcore. */
172 	__ctl_store(cr0, 0, 0);
173 	cr0_new = cr0 & ~(1UL << 28);
174 	__ctl_load(cr0_new, 0, 0);
175 	S390_lowcore.program_old_psw.addr = extable_fixup(fixup);
176 	__ctl_load(cr0, 0, 0);
177 }
178 
179 static noinline __init void setup_lowcore_early(void)
180 {
181 	psw_t psw;
182 
183 	psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
184 	psw.addr = (unsigned long) s390_base_ext_handler;
185 	S390_lowcore.external_new_psw = psw;
186 	psw.addr = (unsigned long) s390_base_pgm_handler;
187 	S390_lowcore.program_new_psw = psw;
188 	s390_base_pgm_handler_fn = early_pgm_check_handler;
189 	S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
190 }
191 
192 static noinline __init void setup_facility_list(void)
193 {
194 	stfle(S390_lowcore.stfle_fac_list,
195 	      ARRAY_SIZE(S390_lowcore.stfle_fac_list));
196 	memcpy(S390_lowcore.alt_stfle_fac_list,
197 	       S390_lowcore.stfle_fac_list,
198 	       sizeof(S390_lowcore.alt_stfle_fac_list));
199 	if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
200 		__clear_facility(82, S390_lowcore.alt_stfle_fac_list);
201 }
202 
203 static __init void detect_diag9c(void)
204 {
205 	unsigned int cpu_address;
206 	int rc;
207 
208 	cpu_address = stap();
209 	diag_stat_inc(DIAG_STAT_X09C);
210 	asm volatile(
211 		"	diag	%2,0,0x9c\n"
212 		"0:	la	%0,0\n"
213 		"1:\n"
214 		EX_TABLE(0b,1b)
215 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
216 	if (!rc)
217 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
218 }
219 
220 static __init void detect_diag44(void)
221 {
222 	int rc;
223 
224 	diag_stat_inc(DIAG_STAT_X044);
225 	asm volatile(
226 		"	diag	0,0,0x44\n"
227 		"0:	la	%0,0\n"
228 		"1:\n"
229 		EX_TABLE(0b,1b)
230 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
231 	if (!rc)
232 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
233 }
234 
235 static __init void detect_machine_facilities(void)
236 {
237 	if (test_facility(8)) {
238 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
239 		__ctl_set_bit(0, 23);
240 	}
241 	if (test_facility(78))
242 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
243 	if (test_facility(3))
244 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
245 	if (test_facility(40))
246 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPP;
247 	if (test_facility(50) && test_facility(73)) {
248 		S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
249 		__ctl_set_bit(0, 55);
250 	}
251 	if (test_facility(51))
252 		S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
253 	if (test_facility(129)) {
254 		S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
255 		__ctl_set_bit(0, 17);
256 	}
257 	if (test_facility(130)) {
258 		S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
259 		__ctl_set_bit(0, 20);
260 	}
261 	if (test_facility(133))
262 		S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
263 	if (test_facility(139) && (tod_clock_base[1] & 0x80)) {
264 		/* Enabled signed clock comparator comparisons */
265 		S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
266 		clock_comparator_max = -1ULL >> 1;
267 		__ctl_set_bit(0, 53);
268 	}
269 }
270 
271 static inline void save_vector_registers(void)
272 {
273 #ifdef CONFIG_CRASH_DUMP
274 	if (test_facility(129))
275 		save_vx_regs(boot_cpu_vector_save_area);
276 #endif
277 }
278 
279 static int __init disable_vector_extension(char *str)
280 {
281 	S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
282 	__ctl_clear_bit(0, 17);
283 	return 0;
284 }
285 early_param("novx", disable_vector_extension);
286 
287 static int __init noexec_setup(char *str)
288 {
289 	bool enabled;
290 	int rc;
291 
292 	rc = kstrtobool(str, &enabled);
293 	if (!rc && !enabled) {
294 		/* Disable no-execute support */
295 		S390_lowcore.machine_flags &= ~MACHINE_FLAG_NX;
296 		__ctl_clear_bit(0, 20);
297 	}
298 	return rc;
299 }
300 early_param("noexec", noexec_setup);
301 
302 static int __init cad_setup(char *str)
303 {
304 	bool enabled;
305 	int rc;
306 
307 	rc = kstrtobool(str, &enabled);
308 	if (!rc && enabled && test_facility(128))
309 		/* Enable problem state CAD. */
310 		__ctl_set_bit(2, 3);
311 	return rc;
312 }
313 early_param("cad", cad_setup);
314 
315 static __init void memmove_early(void *dst, const void *src, size_t n)
316 {
317 	unsigned long addr;
318 	long incr;
319 	psw_t old;
320 
321 	if (!n)
322 		return;
323 	incr = 1;
324 	if (dst > src) {
325 		incr = -incr;
326 		dst += n - 1;
327 		src += n - 1;
328 	}
329 	old = S390_lowcore.program_new_psw;
330 	S390_lowcore.program_new_psw.mask = __extract_psw();
331 	asm volatile(
332 		"	larl	%[addr],1f\n"
333 		"	stg	%[addr],%[psw_pgm_addr]\n"
334 		"0:     mvc	0(1,%[dst]),0(%[src])\n"
335 		"	agr	%[dst],%[incr]\n"
336 		"	agr	%[src],%[incr]\n"
337 		"	brctg	%[n],0b\n"
338 		"1:\n"
339 		: [addr] "=&d" (addr),
340 		  [psw_pgm_addr] "=Q" (S390_lowcore.program_new_psw.addr),
341 		  [dst] "+&a" (dst), [src] "+&a" (src),  [n] "+d" (n)
342 		: [incr] "d" (incr)
343 		: "cc", "memory");
344 	S390_lowcore.program_new_psw = old;
345 }
346 
347 static __init noinline void ipl_save_parameters(void)
348 {
349 	void *src, *dst;
350 
351 	src = (void *)(unsigned long) S390_lowcore.ipl_parmblock_ptr;
352 	dst = (void *) IPL_PARMBLOCK_ORIGIN;
353 	memmove_early(dst, src, PAGE_SIZE);
354 	S390_lowcore.ipl_parmblock_ptr = IPL_PARMBLOCK_ORIGIN;
355 }
356 
357 static __init noinline void rescue_initrd(void)
358 {
359 #ifdef CONFIG_BLK_DEV_INITRD
360 	unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
361 	/*
362 	 * Just like in case of IPL from VM reader we make sure there is a
363 	 * gap of 4MB between end of kernel and start of initrd.
364 	 * That way we can also be sure that saving an NSS will succeed,
365 	 * which however only requires different segments.
366 	 */
367 	if (!INITRD_START || !INITRD_SIZE)
368 		return;
369 	if (INITRD_START >= min_initrd_addr)
370 		return;
371 	memmove_early((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
372 	INITRD_START = min_initrd_addr;
373 #endif
374 }
375 
376 /* Set up boot command line */
377 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
378 {
379 	char *parm, *delim;
380 	size_t rc, len;
381 
382 	len = strlen(boot_command_line);
383 
384 	delim = boot_command_line + len;	/* '\0' character position */
385 	parm  = boot_command_line + len + 1;	/* append right after '\0' */
386 
387 	rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
388 	if (rc) {
389 		if (*parm == '=')
390 			memmove(boot_command_line, parm + 1, rc);
391 		else
392 			*delim = ' ';		/* replace '\0' with space */
393 	}
394 }
395 
396 static inline int has_ebcdic_char(const char *str)
397 {
398 	int i;
399 
400 	for (i = 0; str[i]; i++)
401 		if (str[i] & 0x80)
402 			return 1;
403 	return 0;
404 }
405 
406 static void __init setup_boot_command_line(void)
407 {
408 	COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
409 	/* convert arch command line to ascii if necessary */
410 	if (has_ebcdic_char(COMMAND_LINE))
411 		EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
412 	/* copy arch command line */
413 	strlcpy(boot_command_line, strstrip(COMMAND_LINE),
414 		ARCH_COMMAND_LINE_SIZE);
415 
416 	/* append IPL PARM data to the boot command line */
417 	if (MACHINE_IS_VM)
418 		append_to_cmdline(append_ipl_vmparm);
419 
420 	append_to_cmdline(append_ipl_scpdata);
421 }
422 
423 void __init startup_init(void)
424 {
425 	reset_tod_clock();
426 	ipl_save_parameters();
427 	rescue_initrd();
428 	clear_bss_section();
429 	ipl_verify_parameters();
430 	time_early_init();
431 	init_kernel_storage_key();
432 	lockdep_off();
433 	setup_lowcore_early();
434 	setup_facility_list();
435 	detect_machine_type();
436 	setup_arch_string();
437 	ipl_update_parameters();
438 	setup_boot_command_line();
439 	detect_diag9c();
440 	detect_diag44();
441 	detect_machine_facilities();
442 	save_vector_registers();
443 	setup_topology();
444 	sclp_early_detect();
445 	lockdep_on();
446 }
447