xref: /openbmc/linux/arch/s390/kernel/early.c (revision 8684014d)
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/module.h>
17 #include <linux/pfn.h>
18 #include <linux/uaccess.h>
19 #include <linux/kernel.h>
20 #include <asm/ebcdic.h>
21 #include <asm/ipl.h>
22 #include <asm/lowcore.h>
23 #include <asm/processor.h>
24 #include <asm/sections.h>
25 #include <asm/setup.h>
26 #include <asm/sysinfo.h>
27 #include <asm/cpcmd.h>
28 #include <asm/sclp.h>
29 #include <asm/facility.h>
30 #include "entry.h"
31 
32 /*
33  * Create a Kernel NSS if the SAVESYS= parameter is defined
34  */
35 #define DEFSYS_CMD_SIZE		128
36 #define SAVESYS_CMD_SIZE	32
37 
38 char kernel_nss_name[NSS_NAME_SIZE + 1];
39 
40 static void __init setup_boot_command_line(void);
41 
42 /*
43  * Get the TOD clock running.
44  */
45 static void __init reset_tod_clock(void)
46 {
47 	u64 time;
48 
49 	if (store_tod_clock(&time) == 0)
50 		return;
51 	/* TOD clock not running. Set the clock to Unix Epoch. */
52 	if (set_tod_clock(TOD_UNIX_EPOCH) != 0 || store_tod_clock(&time) != 0)
53 		disabled_wait(0);
54 
55 	sched_clock_base_cc = TOD_UNIX_EPOCH;
56 	S390_lowcore.last_update_clock = sched_clock_base_cc;
57 }
58 
59 #ifdef CONFIG_SHARED_KERNEL
60 int __init savesys_ipl_nss(char *cmd, const int cmdlen);
61 
62 asm(
63 	"	.section .init.text,\"ax\",@progbits\n"
64 	"	.align	4\n"
65 	"	.type	savesys_ipl_nss, @function\n"
66 	"savesys_ipl_nss:\n"
67 #ifdef CONFIG_64BIT
68 	"	stmg	6,15,48(15)\n"
69 	"	lgr	14,3\n"
70 	"	sam31\n"
71 	"	diag	2,14,0x8\n"
72 	"	sam64\n"
73 	"	lgr	2,14\n"
74 	"	lmg	6,15,48(15)\n"
75 #else
76 	"	stm	6,15,24(15)\n"
77 	"	lr	14,3\n"
78 	"	diag	2,14,0x8\n"
79 	"	lr	2,14\n"
80 	"	lm	6,15,24(15)\n"
81 #endif
82 	"	br	14\n"
83 	"	.size	savesys_ipl_nss, .-savesys_ipl_nss\n"
84 	"	.previous\n");
85 
86 static __initdata char upper_command_line[COMMAND_LINE_SIZE];
87 
88 static noinline __init void create_kernel_nss(void)
89 {
90 	unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
91 #ifdef CONFIG_BLK_DEV_INITRD
92 	unsigned int sinitrd_pfn, einitrd_pfn;
93 #endif
94 	int response;
95 	int hlen;
96 	size_t len;
97 	char *savesys_ptr;
98 	char defsys_cmd[DEFSYS_CMD_SIZE];
99 	char savesys_cmd[SAVESYS_CMD_SIZE];
100 
101 	/* Do nothing if we are not running under VM */
102 	if (!MACHINE_IS_VM)
103 		return;
104 
105 	/* Convert COMMAND_LINE to upper case */
106 	for (i = 0; i < strlen(boot_command_line); i++)
107 		upper_command_line[i] = toupper(boot_command_line[i]);
108 
109 	savesys_ptr = strstr(upper_command_line, "SAVESYS=");
110 
111 	if (!savesys_ptr)
112 		return;
113 
114 	savesys_ptr += 8;    /* Point to the beginning of the NSS name */
115 	for (i = 0; i < NSS_NAME_SIZE; i++) {
116 		if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0')
117 			break;
118 		kernel_nss_name[i] = savesys_ptr[i];
119 	}
120 
121 	stext_pfn = PFN_DOWN(__pa(&_stext));
122 	eshared_pfn = PFN_DOWN(__pa(&_eshared));
123 	end_pfn = PFN_UP(__pa(&_end));
124 	min_size = end_pfn << 2;
125 
126 	hlen = snprintf(defsys_cmd, DEFSYS_CMD_SIZE,
127 			"DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
128 			kernel_nss_name, stext_pfn - 1, stext_pfn,
129 			eshared_pfn - 1, eshared_pfn, end_pfn);
130 
131 #ifdef CONFIG_BLK_DEV_INITRD
132 	if (INITRD_START && INITRD_SIZE) {
133 		sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
134 		einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
135 		min_size = einitrd_pfn << 2;
136 		hlen += snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
137 				 " EW %.5X-%.5X", sinitrd_pfn, einitrd_pfn);
138 	}
139 #endif
140 
141 	snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
142 		 " EW MINSIZE=%.7iK PARMREGS=0-13", min_size);
143 	defsys_cmd[DEFSYS_CMD_SIZE - 1] = '\0';
144 	snprintf(savesys_cmd, SAVESYS_CMD_SIZE, "SAVESYS %s \n IPL %s",
145 		 kernel_nss_name, kernel_nss_name);
146 	savesys_cmd[SAVESYS_CMD_SIZE - 1] = '\0';
147 
148 	__cpcmd(defsys_cmd, NULL, 0, &response);
149 
150 	if (response != 0) {
151 		pr_err("Defining the Linux kernel NSS failed with rc=%d\n",
152 			response);
153 		kernel_nss_name[0] = '\0';
154 		return;
155 	}
156 
157 	len = strlen(savesys_cmd);
158 	ASCEBC(savesys_cmd, len);
159 	response = savesys_ipl_nss(savesys_cmd, len);
160 
161 	/* On success: response is equal to the command size,
162 	 *	       max SAVESYS_CMD_SIZE
163 	 * On error: response contains the numeric portion of cp error message.
164 	 *	     for SAVESYS it will be >= 263
165 	 *	     for missing privilege class, it will be 1
166 	 */
167 	if (response > SAVESYS_CMD_SIZE || response == 1) {
168 		pr_err("Saving the Linux kernel NSS failed with rc=%d\n",
169 			response);
170 		kernel_nss_name[0] = '\0';
171 		return;
172 	}
173 
174 	/* re-initialize cputime accounting. */
175 	sched_clock_base_cc = get_tod_clock();
176 	S390_lowcore.last_update_clock = sched_clock_base_cc;
177 	S390_lowcore.last_update_timer = 0x7fffffffffffffffULL;
178 	S390_lowcore.user_timer = 0;
179 	S390_lowcore.system_timer = 0;
180 	asm volatile("SPT 0(%0)" : : "a" (&S390_lowcore.last_update_timer));
181 
182 	/* re-setup boot command line with new ipl vm parms */
183 	ipl_update_parameters();
184 	setup_boot_command_line();
185 
186 	ipl_flags = IPL_NSS_VALID;
187 }
188 
189 #else /* CONFIG_SHARED_KERNEL */
190 
191 static inline void create_kernel_nss(void) { }
192 
193 #endif /* CONFIG_SHARED_KERNEL */
194 
195 /*
196  * Clear bss memory
197  */
198 static noinline __init void clear_bss_section(void)
199 {
200 	memset(__bss_start, 0, __bss_stop - __bss_start);
201 }
202 
203 /*
204  * Initialize storage key for kernel pages
205  */
206 static noinline __init void init_kernel_storage_key(void)
207 {
208 #if PAGE_DEFAULT_KEY
209 	unsigned long end_pfn, init_pfn;
210 
211 	end_pfn = PFN_UP(__pa(&_end));
212 
213 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
214 		page_set_storage_key(init_pfn << PAGE_SHIFT,
215 				     PAGE_DEFAULT_KEY, 0);
216 #endif
217 }
218 
219 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
220 
221 static noinline __init void detect_machine_type(void)
222 {
223 	struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
224 
225 	/* Check current-configuration-level */
226 	if (stsi(NULL, 0, 0, 0) <= 2) {
227 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
228 		return;
229 	}
230 	/* Get virtual-machine cpu information. */
231 	if (stsi(vmms, 3, 2, 2) || !vmms->count)
232 		return;
233 
234 	/* Running under KVM? If not we assume z/VM */
235 	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
236 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
237 	else
238 		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
239 }
240 
241 static __init void setup_topology(void)
242 {
243 #ifdef CONFIG_64BIT
244 	int max_mnest;
245 
246 	if (!test_facility(11))
247 		return;
248 	S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
249 	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
250 		if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
251 			break;
252 	}
253 	topology_max_mnest = max_mnest;
254 #endif
255 }
256 
257 static void early_pgm_check_handler(void)
258 {
259 	const struct exception_table_entry *fixup;
260 	unsigned long cr0, cr0_new;
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 	/* Disable low address protection before storing into lowcore. */
268 	__ctl_store(cr0, 0, 0);
269 	cr0_new = cr0 & ~(1UL << 28);
270 	__ctl_load(cr0_new, 0, 0);
271 	S390_lowcore.program_old_psw.addr = extable_fixup(fixup)|PSW_ADDR_AMODE;
272 	__ctl_load(cr0, 0, 0);
273 }
274 
275 static noinline __init void setup_lowcore_early(void)
276 {
277 	psw_t psw;
278 
279 	psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
280 	psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
281 	S390_lowcore.external_new_psw = psw;
282 	psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
283 	S390_lowcore.program_new_psw = psw;
284 	s390_base_pgm_handler_fn = early_pgm_check_handler;
285 }
286 
287 static noinline __init void setup_facility_list(void)
288 {
289 	stfle(S390_lowcore.stfle_fac_list,
290 	      ARRAY_SIZE(S390_lowcore.stfle_fac_list));
291 }
292 
293 static __init void detect_mvpg(void)
294 {
295 #ifndef CONFIG_64BIT
296 	int rc;
297 
298 	asm volatile(
299 		"	la	0,0\n"
300 		"	mvpg	%2,%2\n"
301 		"0:	la	%0,0\n"
302 		"1:\n"
303 		EX_TABLE(0b,1b)
304 		: "=d" (rc) : "0" (-EOPNOTSUPP), "a" (0) : "memory", "cc", "0");
305 	if (!rc)
306 		S390_lowcore.machine_flags |= MACHINE_FLAG_MVPG;
307 #endif
308 }
309 
310 static __init void detect_ieee(void)
311 {
312 #ifndef CONFIG_64BIT
313 	int rc, tmp;
314 
315 	asm volatile(
316 		"	efpc	%1,0\n"
317 		"0:	la	%0,0\n"
318 		"1:\n"
319 		EX_TABLE(0b,1b)
320 		: "=d" (rc), "=d" (tmp): "0" (-EOPNOTSUPP) : "cc");
321 	if (!rc)
322 		S390_lowcore.machine_flags |= MACHINE_FLAG_IEEE;
323 #endif
324 }
325 
326 static __init void detect_csp(void)
327 {
328 #ifndef CONFIG_64BIT
329 	int rc;
330 
331 	asm volatile(
332 		"	la	0,0\n"
333 		"	la	1,0\n"
334 		"	la	2,4\n"
335 		"	csp	0,2\n"
336 		"0:	la	%0,0\n"
337 		"1:\n"
338 		EX_TABLE(0b,1b)
339 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc", "0", "1", "2");
340 	if (!rc)
341 		S390_lowcore.machine_flags |= MACHINE_FLAG_CSP;
342 #endif
343 }
344 
345 static __init void detect_diag9c(void)
346 {
347 	unsigned int cpu_address;
348 	int rc;
349 
350 	cpu_address = stap();
351 	asm volatile(
352 		"	diag	%2,0,0x9c\n"
353 		"0:	la	%0,0\n"
354 		"1:\n"
355 		EX_TABLE(0b,1b)
356 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
357 	if (!rc)
358 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
359 }
360 
361 static __init void detect_diag44(void)
362 {
363 #ifdef CONFIG_64BIT
364 	int rc;
365 
366 	asm volatile(
367 		"	diag	0,0,0x44\n"
368 		"0:	la	%0,0\n"
369 		"1:\n"
370 		EX_TABLE(0b,1b)
371 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
372 	if (!rc)
373 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
374 #endif
375 }
376 
377 static __init void detect_machine_facilities(void)
378 {
379 #ifdef CONFIG_64BIT
380 	if (test_facility(8)) {
381 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
382 		__ctl_set_bit(0, 23);
383 	}
384 	if (test_facility(78))
385 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
386 	if (test_facility(3))
387 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
388 	if (test_facility(40))
389 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPP;
390 	if (test_facility(50) && test_facility(73))
391 		S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
392 	if (test_facility(51))
393 		S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
394 	if (test_facility(129))
395 		S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
396 #endif
397 }
398 
399 static __init void rescue_initrd(void)
400 {
401 #ifdef CONFIG_BLK_DEV_INITRD
402 	unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
403 	/*
404 	 * Just like in case of IPL from VM reader we make sure there is a
405 	 * gap of 4MB between end of kernel and start of initrd.
406 	 * That way we can also be sure that saving an NSS will succeed,
407 	 * which however only requires different segments.
408 	 */
409 	if (!INITRD_START || !INITRD_SIZE)
410 		return;
411 	if (INITRD_START >= min_initrd_addr)
412 		return;
413 	memmove((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
414 	INITRD_START = min_initrd_addr;
415 #endif
416 }
417 
418 /* Set up boot command line */
419 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
420 {
421 	char *parm, *delim;
422 	size_t rc, len;
423 
424 	len = strlen(boot_command_line);
425 
426 	delim = boot_command_line + len;	/* '\0' character position */
427 	parm  = boot_command_line + len + 1;	/* append right after '\0' */
428 
429 	rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
430 	if (rc) {
431 		if (*parm == '=')
432 			memmove(boot_command_line, parm + 1, rc);
433 		else
434 			*delim = ' ';		/* replace '\0' with space */
435 	}
436 }
437 
438 static inline int has_ebcdic_char(const char *str)
439 {
440 	int i;
441 
442 	for (i = 0; str[i]; i++)
443 		if (str[i] & 0x80)
444 			return 1;
445 	return 0;
446 }
447 
448 static void __init setup_boot_command_line(void)
449 {
450 	COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
451 	/* convert arch command line to ascii if necessary */
452 	if (has_ebcdic_char(COMMAND_LINE))
453 		EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
454 	/* copy arch command line */
455 	strlcpy(boot_command_line, strstrip(COMMAND_LINE),
456 		ARCH_COMMAND_LINE_SIZE);
457 
458 	/* append IPL PARM data to the boot command line */
459 	if (MACHINE_IS_VM)
460 		append_to_cmdline(append_ipl_vmparm);
461 
462 	append_to_cmdline(append_ipl_scpdata);
463 }
464 
465 /*
466  * Save ipl parameters, clear bss memory, initialize storage keys
467  * and create a kernel NSS at startup if the SAVESYS= parm is defined
468  */
469 void __init startup_init(void)
470 {
471 	reset_tod_clock();
472 	ipl_save_parameters();
473 	rescue_initrd();
474 	clear_bss_section();
475 	init_kernel_storage_key();
476 	lockdep_init();
477 	lockdep_off();
478 	setup_lowcore_early();
479 	setup_facility_list();
480 	detect_machine_type();
481 	ipl_update_parameters();
482 	setup_boot_command_line();
483 	create_kernel_nss();
484 	detect_mvpg();
485 	detect_ieee();
486 	detect_csp();
487 	detect_diag9c();
488 	detect_diag44();
489 	detect_machine_facilities();
490 	setup_topology();
491 	sclp_early_detect();
492 	lockdep_on();
493 }
494