xref: /openbmc/linux/arch/s390/kernel/early.c (revision bc000245)
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/ftrace.h>
16 #include <linux/lockdep.h>
17 #include <linux/module.h>
18 #include <linux/pfn.h>
19 #include <linux/uaccess.h>
20 #include <linux/kernel.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 #ifdef CONFIG_64BIT
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 #else
77 	"	stm	6,15,24(15)\n"
78 	"	lr	14,3\n"
79 	"	diag	2,14,0x8\n"
80 	"	lr	2,14\n"
81 	"	lm	6,15,24(15)\n"
82 #endif
83 	"	br	14\n"
84 	"	.size	savesys_ipl_nss, .-savesys_ipl_nss\n"
85 	"	.previous\n");
86 
87 static __initdata char upper_command_line[COMMAND_LINE_SIZE];
88 
89 static noinline __init void create_kernel_nss(void)
90 {
91 	unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
92 #ifdef CONFIG_BLK_DEV_INITRD
93 	unsigned int sinitrd_pfn, einitrd_pfn;
94 #endif
95 	int response;
96 	int hlen;
97 	size_t len;
98 	char *savesys_ptr;
99 	char defsys_cmd[DEFSYS_CMD_SIZE];
100 	char savesys_cmd[SAVESYS_CMD_SIZE];
101 
102 	/* Do nothing if we are not running under VM */
103 	if (!MACHINE_IS_VM)
104 		return;
105 
106 	/* Convert COMMAND_LINE to upper case */
107 	for (i = 0; i < strlen(boot_command_line); i++)
108 		upper_command_line[i] = toupper(boot_command_line[i]);
109 
110 	savesys_ptr = strstr(upper_command_line, "SAVESYS=");
111 
112 	if (!savesys_ptr)
113 		return;
114 
115 	savesys_ptr += 8;    /* Point to the beginning of the NSS name */
116 	for (i = 0; i < NSS_NAME_SIZE; i++) {
117 		if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0')
118 			break;
119 		kernel_nss_name[i] = savesys_ptr[i];
120 	}
121 
122 	stext_pfn = PFN_DOWN(__pa(&_stext));
123 	eshared_pfn = PFN_DOWN(__pa(&_eshared));
124 	end_pfn = PFN_UP(__pa(&_end));
125 	min_size = end_pfn << 2;
126 
127 	hlen = snprintf(defsys_cmd, DEFSYS_CMD_SIZE,
128 			"DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
129 			kernel_nss_name, stext_pfn - 1, stext_pfn,
130 			eshared_pfn - 1, eshared_pfn, end_pfn);
131 
132 #ifdef CONFIG_BLK_DEV_INITRD
133 	if (INITRD_START && INITRD_SIZE) {
134 		sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
135 		einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
136 		min_size = einitrd_pfn << 2;
137 		hlen += snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
138 				 " EW %.5X-%.5X", sinitrd_pfn, einitrd_pfn);
139 	}
140 #endif
141 
142 	snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
143 		 " EW MINSIZE=%.7iK PARMREGS=0-13", min_size);
144 	defsys_cmd[DEFSYS_CMD_SIZE - 1] = '\0';
145 	snprintf(savesys_cmd, SAVESYS_CMD_SIZE, "SAVESYS %s \n IPL %s",
146 		 kernel_nss_name, kernel_nss_name);
147 	savesys_cmd[SAVESYS_CMD_SIZE - 1] = '\0';
148 
149 	__cpcmd(defsys_cmd, NULL, 0, &response);
150 
151 	if (response != 0) {
152 		pr_err("Defining the Linux kernel NSS failed with rc=%d\n",
153 			response);
154 		kernel_nss_name[0] = '\0';
155 		return;
156 	}
157 
158 	len = strlen(savesys_cmd);
159 	ASCEBC(savesys_cmd, len);
160 	response = savesys_ipl_nss(savesys_cmd, len);
161 
162 	/* On success: response is equal to the command size,
163 	 *	       max SAVESYS_CMD_SIZE
164 	 * On error: response contains the numeric portion of cp error message.
165 	 *	     for SAVESYS it will be >= 263
166 	 *	     for missing privilege class, it will be 1
167 	 */
168 	if (response > SAVESYS_CMD_SIZE || response == 1) {
169 		pr_err("Saving the Linux kernel NSS failed with rc=%d\n",
170 			response);
171 		kernel_nss_name[0] = '\0';
172 		return;
173 	}
174 
175 	/* re-initialize cputime accounting. */
176 	sched_clock_base_cc = get_tod_clock();
177 	S390_lowcore.last_update_clock = sched_clock_base_cc;
178 	S390_lowcore.last_update_timer = 0x7fffffffffffffffULL;
179 	S390_lowcore.user_timer = 0;
180 	S390_lowcore.system_timer = 0;
181 	asm volatile("SPT 0(%0)" : : "a" (&S390_lowcore.last_update_timer));
182 
183 	/* re-setup boot command line with new ipl vm parms */
184 	ipl_update_parameters();
185 	setup_boot_command_line();
186 
187 	ipl_flags = IPL_NSS_VALID;
188 }
189 
190 #else /* CONFIG_SHARED_KERNEL */
191 
192 static inline void create_kernel_nss(void) { }
193 
194 #endif /* CONFIG_SHARED_KERNEL */
195 
196 /*
197  * Clear bss memory
198  */
199 static noinline __init void clear_bss_section(void)
200 {
201 	memset(__bss_start, 0, __bss_stop - __bss_start);
202 }
203 
204 /*
205  * Initialize storage key for kernel pages
206  */
207 static noinline __init void init_kernel_storage_key(void)
208 {
209 #if PAGE_DEFAULT_KEY
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 #endif
218 }
219 
220 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
221 
222 static noinline __init void detect_machine_type(void)
223 {
224 	struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
225 
226 	/* Check current-configuration-level */
227 	if (stsi(NULL, 0, 0, 0) <= 2) {
228 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
229 		return;
230 	}
231 	/* Get virtual-machine cpu information. */
232 	if (stsi(vmms, 3, 2, 2) || !vmms->count)
233 		return;
234 
235 	/* Running under KVM? If not we assume z/VM */
236 	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
237 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
238 	else
239 		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
240 }
241 
242 static __init void setup_topology(void)
243 {
244 #ifdef CONFIG_64BIT
245 	int max_mnest;
246 
247 	if (!test_facility(11))
248 		return;
249 	S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
250 	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
251 		if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
252 			break;
253 	}
254 	topology_max_mnest = max_mnest;
255 #endif
256 }
257 
258 static void early_pgm_check_handler(void)
259 {
260 	const struct exception_table_entry *fixup;
261 	unsigned long addr;
262 
263 	addr = S390_lowcore.program_old_psw.addr;
264 	fixup = search_exception_tables(addr & PSW_ADDR_INSN);
265 	if (!fixup)
266 		disabled_wait(0);
267 	S390_lowcore.program_old_psw.addr = extable_fixup(fixup)|PSW_ADDR_AMODE;
268 }
269 
270 static noinline __init void setup_lowcore_early(void)
271 {
272 	psw_t psw;
273 
274 	psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
275 	psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
276 	S390_lowcore.external_new_psw = psw;
277 	psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
278 	S390_lowcore.program_new_psw = psw;
279 	s390_base_pgm_handler_fn = early_pgm_check_handler;
280 }
281 
282 static noinline __init void setup_facility_list(void)
283 {
284 	stfle(S390_lowcore.stfle_fac_list,
285 	      ARRAY_SIZE(S390_lowcore.stfle_fac_list));
286 }
287 
288 static __init void detect_mvpg(void)
289 {
290 #ifndef CONFIG_64BIT
291 	int rc;
292 
293 	asm volatile(
294 		"	la	0,0\n"
295 		"	mvpg	%2,%2\n"
296 		"0:	la	%0,0\n"
297 		"1:\n"
298 		EX_TABLE(0b,1b)
299 		: "=d" (rc) : "0" (-EOPNOTSUPP), "a" (0) : "memory", "cc", "0");
300 	if (!rc)
301 		S390_lowcore.machine_flags |= MACHINE_FLAG_MVPG;
302 #endif
303 }
304 
305 static __init void detect_ieee(void)
306 {
307 #ifndef CONFIG_64BIT
308 	int rc, tmp;
309 
310 	asm volatile(
311 		"	efpc	%1,0\n"
312 		"0:	la	%0,0\n"
313 		"1:\n"
314 		EX_TABLE(0b,1b)
315 		: "=d" (rc), "=d" (tmp): "0" (-EOPNOTSUPP) : "cc");
316 	if (!rc)
317 		S390_lowcore.machine_flags |= MACHINE_FLAG_IEEE;
318 #endif
319 }
320 
321 static __init void detect_csp(void)
322 {
323 #ifndef CONFIG_64BIT
324 	int rc;
325 
326 	asm volatile(
327 		"	la	0,0\n"
328 		"	la	1,0\n"
329 		"	la	2,4\n"
330 		"	csp	0,2\n"
331 		"0:	la	%0,0\n"
332 		"1:\n"
333 		EX_TABLE(0b,1b)
334 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc", "0", "1", "2");
335 	if (!rc)
336 		S390_lowcore.machine_flags |= MACHINE_FLAG_CSP;
337 #endif
338 }
339 
340 static __init void detect_diag9c(void)
341 {
342 	unsigned int cpu_address;
343 	int rc;
344 
345 	cpu_address = stap();
346 	asm volatile(
347 		"	diag	%2,0,0x9c\n"
348 		"0:	la	%0,0\n"
349 		"1:\n"
350 		EX_TABLE(0b,1b)
351 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
352 	if (!rc)
353 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
354 }
355 
356 static __init void detect_diag44(void)
357 {
358 #ifdef CONFIG_64BIT
359 	int rc;
360 
361 	asm volatile(
362 		"	diag	0,0,0x44\n"
363 		"0:	la	%0,0\n"
364 		"1:\n"
365 		EX_TABLE(0b,1b)
366 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
367 	if (!rc)
368 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
369 #endif
370 }
371 
372 static __init void detect_machine_facilities(void)
373 {
374 #ifdef CONFIG_64BIT
375 	if (test_facility(8)) {
376 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
377 		__ctl_set_bit(0, 23);
378 	}
379 	if (test_facility(78))
380 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
381 	if (test_facility(3))
382 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
383 	if (test_facility(27))
384 		S390_lowcore.machine_flags |= MACHINE_FLAG_MVCOS;
385 	if (test_facility(40))
386 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPP;
387 	if (test_facility(50) && test_facility(73))
388 		S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
389 	if (test_facility(66))
390 		S390_lowcore.machine_flags |= MACHINE_FLAG_RRBM;
391 #endif
392 }
393 
394 static __init void rescue_initrd(void)
395 {
396 #ifdef CONFIG_BLK_DEV_INITRD
397 	unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
398 	/*
399 	 * Just like in case of IPL from VM reader we make sure there is a
400 	 * gap of 4MB between end of kernel and start of initrd.
401 	 * That way we can also be sure that saving an NSS will succeed,
402 	 * which however only requires different segments.
403 	 */
404 	if (!INITRD_START || !INITRD_SIZE)
405 		return;
406 	if (INITRD_START >= min_initrd_addr)
407 		return;
408 	memmove((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
409 	INITRD_START = min_initrd_addr;
410 #endif
411 }
412 
413 /* Set up boot command line */
414 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
415 {
416 	char *parm, *delim;
417 	size_t rc, len;
418 
419 	len = strlen(boot_command_line);
420 
421 	delim = boot_command_line + len;	/* '\0' character position */
422 	parm  = boot_command_line + len + 1;	/* append right after '\0' */
423 
424 	rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
425 	if (rc) {
426 		if (*parm == '=')
427 			memmove(boot_command_line, parm + 1, rc);
428 		else
429 			*delim = ' ';		/* replace '\0' with space */
430 	}
431 }
432 
433 static inline int has_ebcdic_char(const char *str)
434 {
435 	int i;
436 
437 	for (i = 0; str[i]; i++)
438 		if (str[i] & 0x80)
439 			return 1;
440 	return 0;
441 }
442 
443 static void __init setup_boot_command_line(void)
444 {
445 	COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
446 	/* convert arch command line to ascii if necessary */
447 	if (has_ebcdic_char(COMMAND_LINE))
448 		EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
449 	/* copy arch command line */
450 	strlcpy(boot_command_line, strstrip(COMMAND_LINE),
451 		ARCH_COMMAND_LINE_SIZE);
452 
453 	/* append IPL PARM data to the boot command line */
454 	if (MACHINE_IS_VM)
455 		append_to_cmdline(append_ipl_vmparm);
456 
457 	append_to_cmdline(append_ipl_scpdata);
458 }
459 
460 /*
461  * Save ipl parameters, clear bss memory, initialize storage keys
462  * and create a kernel NSS at startup if the SAVESYS= parm is defined
463  */
464 void __init startup_init(void)
465 {
466 	reset_tod_clock();
467 	ipl_save_parameters();
468 	rescue_initrd();
469 	clear_bss_section();
470 	init_kernel_storage_key();
471 	lockdep_init();
472 	lockdep_off();
473 	setup_lowcore_early();
474 	setup_facility_list();
475 	detect_machine_type();
476 	ipl_update_parameters();
477 	setup_boot_command_line();
478 	create_kernel_nss();
479 	detect_mvpg();
480 	detect_ieee();
481 	detect_csp();
482 	detect_diag9c();
483 	detect_diag44();
484 	detect_machine_facilities();
485 	setup_topology();
486 	sclp_early_detect();
487 #ifdef CONFIG_DYNAMIC_FTRACE
488 	S390_lowcore.ftrace_func = (unsigned long)ftrace_caller;
489 #endif
490 	lockdep_on();
491 }
492