xref: /openbmc/linux/arch/s390/kernel/early.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
1 /*
2  *  arch/s390/kernel/early.c
3  *
4  *    Copyright IBM Corp. 2007, 2009
5  *    Author(s): Hongjie Yang <hongjie@us.ibm.com>,
6  *		 Heiko Carstens <heiko.carstens@de.ibm.com>
7  */
8 
9 #define KMSG_COMPONENT "setup"
10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
11 
12 #include <linux/compiler.h>
13 #include <linux/init.h>
14 #include <linux/errno.h>
15 #include <linux/string.h>
16 #include <linux/ctype.h>
17 #include <linux/ftrace.h>
18 #include <linux/lockdep.h>
19 #include <linux/module.h>
20 #include <linux/pfn.h>
21 #include <linux/uaccess.h>
22 #include <linux/kernel.h>
23 #include <asm/ebcdic.h>
24 #include <asm/ipl.h>
25 #include <asm/lowcore.h>
26 #include <asm/processor.h>
27 #include <asm/sections.h>
28 #include <asm/setup.h>
29 #include <asm/sysinfo.h>
30 #include <asm/cpcmd.h>
31 #include <asm/sclp.h>
32 #include "entry.h"
33 
34 /*
35  * Create a Kernel NSS if the SAVESYS= parameter is defined
36  */
37 #define DEFSYS_CMD_SIZE		128
38 #define SAVESYS_CMD_SIZE	32
39 
40 char kernel_nss_name[NSS_NAME_SIZE + 1];
41 
42 static void __init setup_boot_command_line(void);
43 
44 /*
45  * Get the TOD clock running.
46  */
47 static void __init reset_tod_clock(void)
48 {
49 	u64 time;
50 
51 	if (store_clock(&time) == 0)
52 		return;
53 	/* TOD clock not running. Set the clock to Unix Epoch. */
54 	if (set_clock(TOD_UNIX_EPOCH) != 0 || store_clock(&time) != 0)
55 		disabled_wait(0);
56 
57 	sched_clock_base_cc = TOD_UNIX_EPOCH;
58 	S390_lowcore.last_update_clock = sched_clock_base_cc;
59 }
60 
61 #ifdef CONFIG_SHARED_KERNEL
62 int __init savesys_ipl_nss(char *cmd, const int cmdlen);
63 
64 asm(
65 	"	.section .init.text,\"ax\",@progbits\n"
66 	"	.align	4\n"
67 	"	.type	savesys_ipl_nss, @function\n"
68 	"savesys_ipl_nss:\n"
69 #ifdef CONFIG_64BIT
70 	"	stmg	6,15,48(15)\n"
71 	"	lgr	14,3\n"
72 	"	sam31\n"
73 	"	diag	2,14,0x8\n"
74 	"	sam64\n"
75 	"	lgr	2,14\n"
76 	"	lmg	6,15,48(15)\n"
77 #else
78 	"	stm	6,15,24(15)\n"
79 	"	lr	14,3\n"
80 	"	diag	2,14,0x8\n"
81 	"	lr	2,14\n"
82 	"	lm	6,15,24(15)\n"
83 #endif
84 	"	br	14\n"
85 	"	.size	savesys_ipl_nss, .-savesys_ipl_nss\n"
86 	"	.previous\n");
87 
88 static __initdata char upper_command_line[COMMAND_LINE_SIZE];
89 
90 static noinline __init void create_kernel_nss(void)
91 {
92 	unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
93 #ifdef CONFIG_BLK_DEV_INITRD
94 	unsigned int sinitrd_pfn, einitrd_pfn;
95 #endif
96 	int response;
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 	sprintf(defsys_cmd, "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
128 		kernel_nss_name, stext_pfn - 1, stext_pfn, eshared_pfn - 1,
129 		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 		sprintf(defsys_cmd, "%s EW %.5X-%.5X", defsys_cmd,
137 		sinitrd_pfn, einitrd_pfn);
138 	}
139 #endif
140 
141 	sprintf(defsys_cmd, "%s EW MINSIZE=%.7iK PARMREGS=0-13",
142 		defsys_cmd, min_size);
143 	sprintf(savesys_cmd, "SAVESYS %s \n IPL %s",
144 		kernel_nss_name, kernel_nss_name);
145 
146 	__cpcmd(defsys_cmd, NULL, 0, &response);
147 
148 	if (response != 0) {
149 		pr_err("Defining the Linux kernel NSS failed with rc=%d\n",
150 			response);
151 		kernel_nss_name[0] = '\0';
152 		return;
153 	}
154 
155 	len = strlen(savesys_cmd);
156 	ASCEBC(savesys_cmd, len);
157 	response = savesys_ipl_nss(savesys_cmd, len);
158 
159 	/* On success: response is equal to the command size,
160 	 *	       max SAVESYS_CMD_SIZE
161 	 * On error: response contains the numeric portion of cp error message.
162 	 *	     for SAVESYS it will be >= 263
163 	 *	     for missing privilege class, it will be 1
164 	 */
165 	if (response > SAVESYS_CMD_SIZE || response == 1) {
166 		pr_err("Saving the Linux kernel NSS failed with rc=%d\n",
167 			response);
168 		kernel_nss_name[0] = '\0';
169 		return;
170 	}
171 
172 	/* re-initialize cputime accounting. */
173 	sched_clock_base_cc = get_clock();
174 	S390_lowcore.last_update_clock = sched_clock_base_cc;
175 	S390_lowcore.last_update_timer = 0x7fffffffffffffffULL;
176 	S390_lowcore.user_timer = 0;
177 	S390_lowcore.system_timer = 0;
178 	asm volatile("SPT 0(%0)" : : "a" (&S390_lowcore.last_update_timer));
179 
180 	/* re-setup boot command line with new ipl vm parms */
181 	ipl_update_parameters();
182 	setup_boot_command_line();
183 
184 	ipl_flags = IPL_NSS_VALID;
185 }
186 
187 #else /* CONFIG_SHARED_KERNEL */
188 
189 static inline void create_kernel_nss(void) { }
190 
191 #endif /* CONFIG_SHARED_KERNEL */
192 
193 /*
194  * Clear bss memory
195  */
196 static noinline __init void clear_bss_section(void)
197 {
198 	memset(__bss_start, 0, __bss_stop - __bss_start);
199 }
200 
201 /*
202  * Initialize storage key for kernel pages
203  */
204 static noinline __init void init_kernel_storage_key(void)
205 {
206 	unsigned long end_pfn, init_pfn;
207 
208 	end_pfn = PFN_UP(__pa(&_end));
209 
210 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
211 		page_set_storage_key(init_pfn << PAGE_SHIFT,
212 				     PAGE_DEFAULT_KEY, 0);
213 }
214 
215 static __initdata struct sysinfo_3_2_2 vmms __aligned(PAGE_SIZE);
216 
217 static noinline __init void detect_machine_type(void)
218 {
219 	/* Check current-configuration-level */
220 	if ((stsi(NULL, 0, 0, 0) >> 28) <= 2) {
221 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
222 		return;
223 	}
224 	/* Get virtual-machine cpu information. */
225 	if (stsi(&vmms, 3, 2, 2) == -ENOSYS || !vmms.count)
226 		return;
227 
228 	/* Running under KVM? If not we assume z/VM */
229 	if (!memcmp(vmms.vm[0].cpi, "\xd2\xe5\xd4", 3))
230 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
231 	else
232 		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
233 }
234 
235 static __init void early_pgm_check_handler(void)
236 {
237 	unsigned long addr;
238 	const struct exception_table_entry *fixup;
239 
240 	addr = S390_lowcore.program_old_psw.addr;
241 	fixup = search_exception_tables(addr & PSW_ADDR_INSN);
242 	if (!fixup)
243 		disabled_wait(0);
244 	S390_lowcore.program_old_psw.addr = fixup->fixup | PSW_ADDR_AMODE;
245 }
246 
247 static noinline __init void setup_lowcore_early(void)
248 {
249 	psw_t psw;
250 
251 	psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
252 	psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
253 	S390_lowcore.external_new_psw = psw;
254 	psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
255 	S390_lowcore.program_new_psw = psw;
256 	s390_base_pgm_handler_fn = early_pgm_check_handler;
257 }
258 
259 static noinline __init void setup_facility_list(void)
260 {
261 	unsigned long nr;
262 
263 	S390_lowcore.stfl_fac_list = 0;
264 	asm volatile(
265 		"	.insn	s,0xb2b10000,0(0)\n" /* stfl */
266 		"0:\n"
267 		EX_TABLE(0b,0b) : "=m" (S390_lowcore.stfl_fac_list));
268 	memcpy(&S390_lowcore.stfle_fac_list, &S390_lowcore.stfl_fac_list, 4);
269 	nr = 4;				/* # bytes stored by stfl */
270 	if (test_facility(7)) {
271 		/* More facility bits available with stfle */
272 		register unsigned long reg0 asm("0") = MAX_FACILITY_BIT/64 - 1;
273 		asm volatile(".insn s,0xb2b00000,%0" /* stfle */
274 			     : "=m" (S390_lowcore.stfle_fac_list), "+d" (reg0)
275 			     : : "cc");
276 		nr = (reg0 + 1) * 8;	/* # bytes stored by stfle */
277 	}
278 	memset((char *) S390_lowcore.stfle_fac_list + nr, 0,
279 	       MAX_FACILITY_BIT/8 - nr);
280 }
281 
282 static noinline __init void setup_hpage(void)
283 {
284 #ifndef CONFIG_DEBUG_PAGEALLOC
285 	if (!test_facility(2) || !test_facility(8))
286 		return;
287 	S390_lowcore.machine_flags |= MACHINE_FLAG_HPAGE;
288 	__ctl_set_bit(0, 23);
289 #endif
290 }
291 
292 static __init void detect_mvpg(void)
293 {
294 #ifndef CONFIG_64BIT
295 	int rc;
296 
297 	asm volatile(
298 		"	la	0,0\n"
299 		"	mvpg	%2,%2\n"
300 		"0:	la	%0,0\n"
301 		"1:\n"
302 		EX_TABLE(0b,1b)
303 		: "=d" (rc) : "0" (-EOPNOTSUPP), "a" (0) : "memory", "cc", "0");
304 	if (!rc)
305 		S390_lowcore.machine_flags |= MACHINE_FLAG_MVPG;
306 #endif
307 }
308 
309 static __init void detect_ieee(void)
310 {
311 #ifndef CONFIG_64BIT
312 	int rc, tmp;
313 
314 	asm volatile(
315 		"	efpc	%1,0\n"
316 		"0:	la	%0,0\n"
317 		"1:\n"
318 		EX_TABLE(0b,1b)
319 		: "=d" (rc), "=d" (tmp): "0" (-EOPNOTSUPP) : "cc");
320 	if (!rc)
321 		S390_lowcore.machine_flags |= MACHINE_FLAG_IEEE;
322 #endif
323 }
324 
325 static __init void detect_csp(void)
326 {
327 #ifndef CONFIG_64BIT
328 	int rc;
329 
330 	asm volatile(
331 		"	la	0,0\n"
332 		"	la	1,0\n"
333 		"	la	2,4\n"
334 		"	csp	0,2\n"
335 		"0:	la	%0,0\n"
336 		"1:\n"
337 		EX_TABLE(0b,1b)
338 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc", "0", "1", "2");
339 	if (!rc)
340 		S390_lowcore.machine_flags |= MACHINE_FLAG_CSP;
341 #endif
342 }
343 
344 static __init void detect_diag9c(void)
345 {
346 	unsigned int cpu_address;
347 	int rc;
348 
349 	cpu_address = stap();
350 	asm volatile(
351 		"	diag	%2,0,0x9c\n"
352 		"0:	la	%0,0\n"
353 		"1:\n"
354 		EX_TABLE(0b,1b)
355 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
356 	if (!rc)
357 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
358 }
359 
360 static __init void detect_diag44(void)
361 {
362 #ifdef CONFIG_64BIT
363 	int rc;
364 
365 	asm volatile(
366 		"	diag	0,0,0x44\n"
367 		"0:	la	%0,0\n"
368 		"1:\n"
369 		EX_TABLE(0b,1b)
370 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
371 	if (!rc)
372 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
373 #endif
374 }
375 
376 static __init void detect_machine_facilities(void)
377 {
378 #ifdef CONFIG_64BIT
379 	if (test_facility(3))
380 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
381 	if (test_facility(8))
382 		S390_lowcore.machine_flags |= MACHINE_FLAG_PFMF;
383 	if (test_facility(11))
384 		S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
385 	if (test_facility(27))
386 		S390_lowcore.machine_flags |= MACHINE_FLAG_MVCOS;
387 	if (test_facility(40))
388 		S390_lowcore.machine_flags |= MACHINE_FLAG_SPP;
389 #endif
390 }
391 
392 static __init void rescue_initrd(void)
393 {
394 #ifdef CONFIG_BLK_DEV_INITRD
395 	/*
396 	 * Move the initrd right behind the bss section in case it starts
397 	 * within the bss section. So we don't overwrite it when the bss
398 	 * section gets cleared.
399 	 */
400 	if (!INITRD_START || !INITRD_SIZE)
401 		return;
402 	if (INITRD_START >= (unsigned long) __bss_stop)
403 		return;
404 	memmove(__bss_stop, (void *) INITRD_START, INITRD_SIZE);
405 	INITRD_START = (unsigned long) __bss_stop;
406 #endif
407 }
408 
409 /* Set up boot command line */
410 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
411 {
412 	char *parm, *delim;
413 	size_t rc, len;
414 
415 	len = strlen(boot_command_line);
416 
417 	delim = boot_command_line + len;	/* '\0' character position */
418 	parm  = boot_command_line + len + 1;	/* append right after '\0' */
419 
420 	rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
421 	if (rc) {
422 		if (*parm == '=')
423 			memmove(boot_command_line, parm + 1, rc);
424 		else
425 			*delim = ' ';		/* replace '\0' with space */
426 	}
427 }
428 
429 static void __init setup_boot_command_line(void)
430 {
431 	int i;
432 
433 	/* convert arch command line to ascii */
434 	for (i = 0; i < ARCH_COMMAND_LINE_SIZE; i++)
435 		if (COMMAND_LINE[i] & 0x80)
436 			break;
437 	if (i < ARCH_COMMAND_LINE_SIZE)
438 		EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
439 	COMMAND_LINE[ARCH_COMMAND_LINE_SIZE-1] = 0;
440 
441 	/* copy arch command line */
442 	strlcpy(boot_command_line, strstrip(COMMAND_LINE),
443 		ARCH_COMMAND_LINE_SIZE);
444 
445 	/* append IPL PARM data to the boot command line */
446 	if (MACHINE_IS_VM)
447 		append_to_cmdline(append_ipl_vmparm);
448 
449 	append_to_cmdline(append_ipl_scpdata);
450 }
451 
452 
453 /*
454  * Save ipl parameters, clear bss memory, initialize storage keys
455  * and create a kernel NSS at startup if the SAVESYS= parm is defined
456  */
457 void __init startup_init(void)
458 {
459 	reset_tod_clock();
460 	ipl_save_parameters();
461 	rescue_initrd();
462 	clear_bss_section();
463 	init_kernel_storage_key();
464 	lockdep_init();
465 	lockdep_off();
466 	sort_main_extable();
467 	setup_lowcore_early();
468 	setup_facility_list();
469 	detect_machine_type();
470 	ipl_update_parameters();
471 	setup_boot_command_line();
472 	create_kernel_nss();
473 	detect_mvpg();
474 	detect_ieee();
475 	detect_csp();
476 	detect_diag9c();
477 	detect_diag44();
478 	detect_machine_facilities();
479 	setup_hpage();
480 	sclp_facilities_detect();
481 	detect_memory_layout(memory_chunk);
482 #ifdef CONFIG_DYNAMIC_FTRACE
483 	S390_lowcore.ftrace_func = (unsigned long)ftrace_caller;
484 #endif
485 	lockdep_on();
486 }
487