xref: /openbmc/linux/arch/s390/kernel/early.c (revision 4a3fad70)
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 }
197 
198 static __init void detect_diag9c(void)
199 {
200 	unsigned int cpu_address;
201 	int rc;
202 
203 	cpu_address = stap();
204 	diag_stat_inc(DIAG_STAT_X09C);
205 	asm volatile(
206 		"	diag	%2,0,0x9c\n"
207 		"0:	la	%0,0\n"
208 		"1:\n"
209 		EX_TABLE(0b,1b)
210 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
211 	if (!rc)
212 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
213 }
214 
215 static __init void detect_diag44(void)
216 {
217 	int rc;
218 
219 	diag_stat_inc(DIAG_STAT_X044);
220 	asm volatile(
221 		"	diag	0,0,0x44\n"
222 		"0:	la	%0,0\n"
223 		"1:\n"
224 		EX_TABLE(0b,1b)
225 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
226 	if (!rc)
227 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
228 }
229 
230 static __init void detect_machine_facilities(void)
231 {
232 	if (test_facility(8)) {
233 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
234 		__ctl_set_bit(0, 23);
235 	}
236 	if (test_facility(78))
237 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
238 	if (test_facility(3))
239 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
240 	if (test_facility(40))
241 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPP;
242 	if (test_facility(50) && test_facility(73)) {
243 		S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
244 		__ctl_set_bit(0, 55);
245 	}
246 	if (test_facility(51))
247 		S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
248 	if (test_facility(129)) {
249 		S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
250 		__ctl_set_bit(0, 17);
251 	}
252 	if (test_facility(130)) {
253 		S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
254 		__ctl_set_bit(0, 20);
255 	}
256 	if (test_facility(133))
257 		S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
258 	if (test_facility(139) && (tod_clock_base[1] & 0x80)) {
259 		/* Enabled signed clock comparator comparisons */
260 		S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
261 		clock_comparator_max = -1ULL >> 1;
262 		__ctl_set_bit(0, 53);
263 	}
264 }
265 
266 static inline void save_vector_registers(void)
267 {
268 #ifdef CONFIG_CRASH_DUMP
269 	if (test_facility(129))
270 		save_vx_regs(boot_cpu_vector_save_area);
271 #endif
272 }
273 
274 static int __init disable_vector_extension(char *str)
275 {
276 	S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
277 	__ctl_clear_bit(0, 17);
278 	return 0;
279 }
280 early_param("novx", disable_vector_extension);
281 
282 static int __init noexec_setup(char *str)
283 {
284 	bool enabled;
285 	int rc;
286 
287 	rc = kstrtobool(str, &enabled);
288 	if (!rc && !enabled) {
289 		/* Disable no-execute support */
290 		S390_lowcore.machine_flags &= ~MACHINE_FLAG_NX;
291 		__ctl_clear_bit(0, 20);
292 	}
293 	return rc;
294 }
295 early_param("noexec", noexec_setup);
296 
297 static int __init cad_setup(char *str)
298 {
299 	bool enabled;
300 	int rc;
301 
302 	rc = kstrtobool(str, &enabled);
303 	if (!rc && enabled && test_facility(128))
304 		/* Enable problem state CAD. */
305 		__ctl_set_bit(2, 3);
306 	return rc;
307 }
308 early_param("cad", cad_setup);
309 
310 static __init void memmove_early(void *dst, const void *src, size_t n)
311 {
312 	unsigned long addr;
313 	long incr;
314 	psw_t old;
315 
316 	if (!n)
317 		return;
318 	incr = 1;
319 	if (dst > src) {
320 		incr = -incr;
321 		dst += n - 1;
322 		src += n - 1;
323 	}
324 	old = S390_lowcore.program_new_psw;
325 	S390_lowcore.program_new_psw.mask = __extract_psw();
326 	asm volatile(
327 		"	larl	%[addr],1f\n"
328 		"	stg	%[addr],%[psw_pgm_addr]\n"
329 		"0:     mvc	0(1,%[dst]),0(%[src])\n"
330 		"	agr	%[dst],%[incr]\n"
331 		"	agr	%[src],%[incr]\n"
332 		"	brctg	%[n],0b\n"
333 		"1:\n"
334 		: [addr] "=&d" (addr),
335 		  [psw_pgm_addr] "=Q" (S390_lowcore.program_new_psw.addr),
336 		  [dst] "+&a" (dst), [src] "+&a" (src),  [n] "+d" (n)
337 		: [incr] "d" (incr)
338 		: "cc", "memory");
339 	S390_lowcore.program_new_psw = old;
340 }
341 
342 static __init noinline void ipl_save_parameters(void)
343 {
344 	void *src, *dst;
345 
346 	src = (void *)(unsigned long) S390_lowcore.ipl_parmblock_ptr;
347 	dst = (void *) IPL_PARMBLOCK_ORIGIN;
348 	memmove_early(dst, src, PAGE_SIZE);
349 	S390_lowcore.ipl_parmblock_ptr = IPL_PARMBLOCK_ORIGIN;
350 }
351 
352 static __init noinline void rescue_initrd(void)
353 {
354 #ifdef CONFIG_BLK_DEV_INITRD
355 	unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
356 	/*
357 	 * Just like in case of IPL from VM reader we make sure there is a
358 	 * gap of 4MB between end of kernel and start of initrd.
359 	 * That way we can also be sure that saving an NSS will succeed,
360 	 * which however only requires different segments.
361 	 */
362 	if (!INITRD_START || !INITRD_SIZE)
363 		return;
364 	if (INITRD_START >= min_initrd_addr)
365 		return;
366 	memmove_early((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
367 	INITRD_START = min_initrd_addr;
368 #endif
369 }
370 
371 /* Set up boot command line */
372 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
373 {
374 	char *parm, *delim;
375 	size_t rc, len;
376 
377 	len = strlen(boot_command_line);
378 
379 	delim = boot_command_line + len;	/* '\0' character position */
380 	parm  = boot_command_line + len + 1;	/* append right after '\0' */
381 
382 	rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
383 	if (rc) {
384 		if (*parm == '=')
385 			memmove(boot_command_line, parm + 1, rc);
386 		else
387 			*delim = ' ';		/* replace '\0' with space */
388 	}
389 }
390 
391 static inline int has_ebcdic_char(const char *str)
392 {
393 	int i;
394 
395 	for (i = 0; str[i]; i++)
396 		if (str[i] & 0x80)
397 			return 1;
398 	return 0;
399 }
400 
401 static void __init setup_boot_command_line(void)
402 {
403 	COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
404 	/* convert arch command line to ascii if necessary */
405 	if (has_ebcdic_char(COMMAND_LINE))
406 		EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
407 	/* copy arch command line */
408 	strlcpy(boot_command_line, strstrip(COMMAND_LINE),
409 		ARCH_COMMAND_LINE_SIZE);
410 
411 	/* append IPL PARM data to the boot command line */
412 	if (MACHINE_IS_VM)
413 		append_to_cmdline(append_ipl_vmparm);
414 
415 	append_to_cmdline(append_ipl_scpdata);
416 }
417 
418 void __init startup_init(void)
419 {
420 	reset_tod_clock();
421 	ipl_save_parameters();
422 	rescue_initrd();
423 	clear_bss_section();
424 	ipl_verify_parameters();
425 	time_early_init();
426 	init_kernel_storage_key();
427 	lockdep_off();
428 	setup_lowcore_early();
429 	setup_facility_list();
430 	detect_machine_type();
431 	setup_arch_string();
432 	ipl_update_parameters();
433 	setup_boot_command_line();
434 	detect_diag9c();
435 	detect_diag44();
436 	detect_machine_facilities();
437 	save_vector_registers();
438 	setup_topology();
439 	sclp_early_detect();
440 	lockdep_on();
441 }
442