xref: /openbmc/linux/arch/s390/kernel/early.c (revision 588b48ca)
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 cr0, cr0_new;
262 	unsigned long addr;
263 
264 	addr = S390_lowcore.program_old_psw.addr;
265 	fixup = search_exception_tables(addr & PSW_ADDR_INSN);
266 	if (!fixup)
267 		disabled_wait(0);
268 	/* Disable low address protection before storing into lowcore. */
269 	__ctl_store(cr0, 0, 0);
270 	cr0_new = cr0 & ~(1UL << 28);
271 	__ctl_load(cr0_new, 0, 0);
272 	S390_lowcore.program_old_psw.addr = extable_fixup(fixup)|PSW_ADDR_AMODE;
273 	__ctl_load(cr0, 0, 0);
274 }
275 
276 static noinline __init void setup_lowcore_early(void)
277 {
278 	psw_t psw;
279 
280 	psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
281 	psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
282 	S390_lowcore.external_new_psw = psw;
283 	psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
284 	S390_lowcore.program_new_psw = psw;
285 	s390_base_pgm_handler_fn = early_pgm_check_handler;
286 }
287 
288 static noinline __init void setup_facility_list(void)
289 {
290 	stfle(S390_lowcore.stfle_fac_list,
291 	      ARRAY_SIZE(S390_lowcore.stfle_fac_list));
292 }
293 
294 static __init void detect_mvpg(void)
295 {
296 #ifndef CONFIG_64BIT
297 	int rc;
298 
299 	asm volatile(
300 		"	la	0,0\n"
301 		"	mvpg	%2,%2\n"
302 		"0:	la	%0,0\n"
303 		"1:\n"
304 		EX_TABLE(0b,1b)
305 		: "=d" (rc) : "0" (-EOPNOTSUPP), "a" (0) : "memory", "cc", "0");
306 	if (!rc)
307 		S390_lowcore.machine_flags |= MACHINE_FLAG_MVPG;
308 #endif
309 }
310 
311 static __init void detect_ieee(void)
312 {
313 #ifndef CONFIG_64BIT
314 	int rc, tmp;
315 
316 	asm volatile(
317 		"	efpc	%1,0\n"
318 		"0:	la	%0,0\n"
319 		"1:\n"
320 		EX_TABLE(0b,1b)
321 		: "=d" (rc), "=d" (tmp): "0" (-EOPNOTSUPP) : "cc");
322 	if (!rc)
323 		S390_lowcore.machine_flags |= MACHINE_FLAG_IEEE;
324 #endif
325 }
326 
327 static __init void detect_csp(void)
328 {
329 #ifndef CONFIG_64BIT
330 	int rc;
331 
332 	asm volatile(
333 		"	la	0,0\n"
334 		"	la	1,0\n"
335 		"	la	2,4\n"
336 		"	csp	0,2\n"
337 		"0:	la	%0,0\n"
338 		"1:\n"
339 		EX_TABLE(0b,1b)
340 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc", "0", "1", "2");
341 	if (!rc)
342 		S390_lowcore.machine_flags |= MACHINE_FLAG_CSP;
343 #endif
344 }
345 
346 static __init void detect_diag9c(void)
347 {
348 	unsigned int cpu_address;
349 	int rc;
350 
351 	cpu_address = stap();
352 	asm volatile(
353 		"	diag	%2,0,0x9c\n"
354 		"0:	la	%0,0\n"
355 		"1:\n"
356 		EX_TABLE(0b,1b)
357 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
358 	if (!rc)
359 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
360 }
361 
362 static __init void detect_diag44(void)
363 {
364 #ifdef CONFIG_64BIT
365 	int rc;
366 
367 	asm volatile(
368 		"	diag	0,0,0x44\n"
369 		"0:	la	%0,0\n"
370 		"1:\n"
371 		EX_TABLE(0b,1b)
372 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
373 	if (!rc)
374 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
375 #endif
376 }
377 
378 static __init void detect_machine_facilities(void)
379 {
380 #ifdef CONFIG_64BIT
381 	if (test_facility(8)) {
382 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
383 		__ctl_set_bit(0, 23);
384 	}
385 	if (test_facility(78))
386 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
387 	if (test_facility(3))
388 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
389 	if (test_facility(40))
390 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPP;
391 	if (test_facility(50) && test_facility(73))
392 		S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
393 	if (test_facility(66))
394 		S390_lowcore.machine_flags |= MACHINE_FLAG_RRBM;
395 	if (test_facility(51))
396 		S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
397 #endif
398 }
399 
400 static __init void rescue_initrd(void)
401 {
402 #ifdef CONFIG_BLK_DEV_INITRD
403 	unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
404 	/*
405 	 * Just like in case of IPL from VM reader we make sure there is a
406 	 * gap of 4MB between end of kernel and start of initrd.
407 	 * That way we can also be sure that saving an NSS will succeed,
408 	 * which however only requires different segments.
409 	 */
410 	if (!INITRD_START || !INITRD_SIZE)
411 		return;
412 	if (INITRD_START >= min_initrd_addr)
413 		return;
414 	memmove((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
415 	INITRD_START = min_initrd_addr;
416 #endif
417 }
418 
419 /* Set up boot command line */
420 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
421 {
422 	char *parm, *delim;
423 	size_t rc, len;
424 
425 	len = strlen(boot_command_line);
426 
427 	delim = boot_command_line + len;	/* '\0' character position */
428 	parm  = boot_command_line + len + 1;	/* append right after '\0' */
429 
430 	rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
431 	if (rc) {
432 		if (*parm == '=')
433 			memmove(boot_command_line, parm + 1, rc);
434 		else
435 			*delim = ' ';		/* replace '\0' with space */
436 	}
437 }
438 
439 static inline int has_ebcdic_char(const char *str)
440 {
441 	int i;
442 
443 	for (i = 0; str[i]; i++)
444 		if (str[i] & 0x80)
445 			return 1;
446 	return 0;
447 }
448 
449 static void __init setup_boot_command_line(void)
450 {
451 	COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
452 	/* convert arch command line to ascii if necessary */
453 	if (has_ebcdic_char(COMMAND_LINE))
454 		EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
455 	/* copy arch command line */
456 	strlcpy(boot_command_line, strstrip(COMMAND_LINE),
457 		ARCH_COMMAND_LINE_SIZE);
458 
459 	/* append IPL PARM data to the boot command line */
460 	if (MACHINE_IS_VM)
461 		append_to_cmdline(append_ipl_vmparm);
462 
463 	append_to_cmdline(append_ipl_scpdata);
464 }
465 
466 /*
467  * Save ipl parameters, clear bss memory, initialize storage keys
468  * and create a kernel NSS at startup if the SAVESYS= parm is defined
469  */
470 void __init startup_init(void)
471 {
472 	reset_tod_clock();
473 	ipl_save_parameters();
474 	rescue_initrd();
475 	clear_bss_section();
476 	init_kernel_storage_key();
477 	lockdep_init();
478 	lockdep_off();
479 	setup_lowcore_early();
480 	setup_facility_list();
481 	detect_machine_type();
482 	ipl_update_parameters();
483 	setup_boot_command_line();
484 	create_kernel_nss();
485 	detect_mvpg();
486 	detect_ieee();
487 	detect_csp();
488 	detect_diag9c();
489 	detect_diag44();
490 	detect_machine_facilities();
491 	setup_topology();
492 	sclp_early_detect();
493 #ifdef CONFIG_DYNAMIC_FTRACE
494 	S390_lowcore.ftrace_func = (unsigned long)ftrace_caller;
495 #endif
496 	lockdep_on();
497 }
498