xref: /openbmc/linux/arch/s390/kernel/early.c (revision 0f4630f3)
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/diag.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 	"	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 	"	br	14\n"
76 	"	.size	savesys_ipl_nss, .-savesys_ipl_nss\n"
77 	"	.previous\n");
78 
79 static __initdata char upper_command_line[COMMAND_LINE_SIZE];
80 
81 static noinline __init void create_kernel_nss(void)
82 {
83 	unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
84 #ifdef CONFIG_BLK_DEV_INITRD
85 	unsigned int sinitrd_pfn, einitrd_pfn;
86 #endif
87 	int response;
88 	int hlen;
89 	size_t len;
90 	char *savesys_ptr;
91 	char defsys_cmd[DEFSYS_CMD_SIZE];
92 	char savesys_cmd[SAVESYS_CMD_SIZE];
93 
94 	/* Do nothing if we are not running under VM */
95 	if (!MACHINE_IS_VM)
96 		return;
97 
98 	/* Convert COMMAND_LINE to upper case */
99 	for (i = 0; i < strlen(boot_command_line); i++)
100 		upper_command_line[i] = toupper(boot_command_line[i]);
101 
102 	savesys_ptr = strstr(upper_command_line, "SAVESYS=");
103 
104 	if (!savesys_ptr)
105 		return;
106 
107 	savesys_ptr += 8;    /* Point to the beginning of the NSS name */
108 	for (i = 0; i < NSS_NAME_SIZE; i++) {
109 		if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0')
110 			break;
111 		kernel_nss_name[i] = savesys_ptr[i];
112 	}
113 
114 	stext_pfn = PFN_DOWN(__pa(&_stext));
115 	eshared_pfn = PFN_DOWN(__pa(&_eshared));
116 	end_pfn = PFN_UP(__pa(&_end));
117 	min_size = end_pfn << 2;
118 
119 	hlen = snprintf(defsys_cmd, DEFSYS_CMD_SIZE,
120 			"DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
121 			kernel_nss_name, stext_pfn - 1, stext_pfn,
122 			eshared_pfn - 1, eshared_pfn, end_pfn);
123 
124 #ifdef CONFIG_BLK_DEV_INITRD
125 	if (INITRD_START && INITRD_SIZE) {
126 		sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
127 		einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
128 		min_size = einitrd_pfn << 2;
129 		hlen += snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
130 				 " EW %.5X-%.5X", sinitrd_pfn, einitrd_pfn);
131 	}
132 #endif
133 
134 	snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
135 		 " EW MINSIZE=%.7iK PARMREGS=0-13", min_size);
136 	defsys_cmd[DEFSYS_CMD_SIZE - 1] = '\0';
137 	snprintf(savesys_cmd, SAVESYS_CMD_SIZE, "SAVESYS %s \n IPL %s",
138 		 kernel_nss_name, kernel_nss_name);
139 	savesys_cmd[SAVESYS_CMD_SIZE - 1] = '\0';
140 
141 	__cpcmd(defsys_cmd, NULL, 0, &response);
142 
143 	if (response != 0) {
144 		pr_err("Defining the Linux kernel NSS failed with rc=%d\n",
145 			response);
146 		kernel_nss_name[0] = '\0';
147 		return;
148 	}
149 
150 	len = strlen(savesys_cmd);
151 	ASCEBC(savesys_cmd, len);
152 	response = savesys_ipl_nss(savesys_cmd, len);
153 
154 	/* On success: response is equal to the command size,
155 	 *	       max SAVESYS_CMD_SIZE
156 	 * On error: response contains the numeric portion of cp error message.
157 	 *	     for SAVESYS it will be >= 263
158 	 *	     for missing privilege class, it will be 1
159 	 */
160 	if (response > SAVESYS_CMD_SIZE || response == 1) {
161 		pr_err("Saving the Linux kernel NSS failed with rc=%d\n",
162 			response);
163 		kernel_nss_name[0] = '\0';
164 		return;
165 	}
166 
167 	/* re-initialize cputime accounting. */
168 	sched_clock_base_cc = get_tod_clock();
169 	S390_lowcore.last_update_clock = sched_clock_base_cc;
170 	S390_lowcore.last_update_timer = 0x7fffffffffffffffULL;
171 	S390_lowcore.user_timer = 0;
172 	S390_lowcore.system_timer = 0;
173 	asm volatile("SPT 0(%0)" : : "a" (&S390_lowcore.last_update_timer));
174 
175 	/* re-setup boot command line with new ipl vm parms */
176 	ipl_update_parameters();
177 	setup_boot_command_line();
178 
179 	ipl_flags = IPL_NSS_VALID;
180 }
181 
182 #else /* CONFIG_SHARED_KERNEL */
183 
184 static inline void create_kernel_nss(void) { }
185 
186 #endif /* CONFIG_SHARED_KERNEL */
187 
188 /*
189  * Clear bss memory
190  */
191 static noinline __init void clear_bss_section(void)
192 {
193 	memset(__bss_start, 0, __bss_stop - __bss_start);
194 }
195 
196 /*
197  * Initialize storage key for kernel pages
198  */
199 static noinline __init void init_kernel_storage_key(void)
200 {
201 #if PAGE_DEFAULT_KEY
202 	unsigned long end_pfn, init_pfn;
203 
204 	end_pfn = PFN_UP(__pa(&_end));
205 
206 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
207 		page_set_storage_key(init_pfn << PAGE_SHIFT,
208 				     PAGE_DEFAULT_KEY, 0);
209 #endif
210 }
211 
212 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
213 
214 static noinline __init void detect_machine_type(void)
215 {
216 	struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
217 
218 	/* Check current-configuration-level */
219 	if (stsi(NULL, 0, 0, 0) <= 2) {
220 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
221 		return;
222 	}
223 	/* Get virtual-machine cpu information. */
224 	if (stsi(vmms, 3, 2, 2) || !vmms->count)
225 		return;
226 
227 	/* Running under KVM? If not we assume z/VM */
228 	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
229 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
230 	else
231 		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
232 }
233 
234 static __init void setup_topology(void)
235 {
236 	int max_mnest;
237 
238 	if (!test_facility(11))
239 		return;
240 	S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
241 	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
242 		if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
243 			break;
244 	}
245 	topology_max_mnest = max_mnest;
246 }
247 
248 static void early_pgm_check_handler(void)
249 {
250 	const struct exception_table_entry *fixup;
251 	unsigned long cr0, cr0_new;
252 	unsigned long addr;
253 
254 	addr = S390_lowcore.program_old_psw.addr;
255 	fixup = search_exception_tables(addr & PSW_ADDR_INSN);
256 	if (!fixup)
257 		disabled_wait(0);
258 	/* Disable low address protection before storing into lowcore. */
259 	__ctl_store(cr0, 0, 0);
260 	cr0_new = cr0 & ~(1UL << 28);
261 	__ctl_load(cr0_new, 0, 0);
262 	S390_lowcore.program_old_psw.addr = extable_fixup(fixup)|PSW_ADDR_AMODE;
263 	__ctl_load(cr0, 0, 0);
264 }
265 
266 static noinline __init void setup_lowcore_early(void)
267 {
268 	psw_t psw;
269 
270 	psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
271 	psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
272 	S390_lowcore.external_new_psw = psw;
273 	psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
274 	S390_lowcore.program_new_psw = psw;
275 	s390_base_pgm_handler_fn = early_pgm_check_handler;
276 }
277 
278 static noinline __init void setup_facility_list(void)
279 {
280 	stfle(S390_lowcore.stfle_fac_list,
281 	      ARRAY_SIZE(S390_lowcore.stfle_fac_list));
282 }
283 
284 static __init void detect_diag9c(void)
285 {
286 	unsigned int cpu_address;
287 	int rc;
288 
289 	cpu_address = stap();
290 	diag_stat_inc(DIAG_STAT_X09C);
291 	asm volatile(
292 		"	diag	%2,0,0x9c\n"
293 		"0:	la	%0,0\n"
294 		"1:\n"
295 		EX_TABLE(0b,1b)
296 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
297 	if (!rc)
298 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
299 }
300 
301 static __init void detect_diag44(void)
302 {
303 	int rc;
304 
305 	diag_stat_inc(DIAG_STAT_X044);
306 	asm volatile(
307 		"	diag	0,0,0x44\n"
308 		"0:	la	%0,0\n"
309 		"1:\n"
310 		EX_TABLE(0b,1b)
311 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
312 	if (!rc)
313 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
314 }
315 
316 static __init void detect_machine_facilities(void)
317 {
318 	if (test_facility(8)) {
319 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
320 		__ctl_set_bit(0, 23);
321 	}
322 	if (test_facility(78))
323 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
324 	if (test_facility(3))
325 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
326 	if (test_facility(40))
327 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPP;
328 	if (test_facility(50) && test_facility(73))
329 		S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
330 	if (test_facility(51))
331 		S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
332 	if (test_facility(129)) {
333 		S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
334 		__ctl_set_bit(0, 17);
335 	}
336 }
337 
338 static int __init disable_vector_extension(char *str)
339 {
340 	S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
341 	__ctl_clear_bit(0, 17);
342 	return 1;
343 }
344 early_param("novx", disable_vector_extension);
345 
346 static int __init cad_setup(char *str)
347 {
348 	int val;
349 
350 	get_option(&str, &val);
351 	if (val && test_facility(128))
352 		S390_lowcore.machine_flags |= MACHINE_FLAG_CAD;
353 	return 0;
354 }
355 early_param("cad", cad_setup);
356 
357 static int __init cad_init(void)
358 {
359 	if (MACHINE_HAS_CAD)
360 		/* Enable problem state CAD. */
361 		__ctl_set_bit(2, 3);
362 	return 0;
363 }
364 early_initcall(cad_init);
365 
366 static __init void rescue_initrd(void)
367 {
368 #ifdef CONFIG_BLK_DEV_INITRD
369 	unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
370 	/*
371 	 * Just like in case of IPL from VM reader we make sure there is a
372 	 * gap of 4MB between end of kernel and start of initrd.
373 	 * That way we can also be sure that saving an NSS will succeed,
374 	 * which however only requires different segments.
375 	 */
376 	if (!INITRD_START || !INITRD_SIZE)
377 		return;
378 	if (INITRD_START >= min_initrd_addr)
379 		return;
380 	memmove((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
381 	INITRD_START = min_initrd_addr;
382 #endif
383 }
384 
385 /* Set up boot command line */
386 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
387 {
388 	char *parm, *delim;
389 	size_t rc, len;
390 
391 	len = strlen(boot_command_line);
392 
393 	delim = boot_command_line + len;	/* '\0' character position */
394 	parm  = boot_command_line + len + 1;	/* append right after '\0' */
395 
396 	rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
397 	if (rc) {
398 		if (*parm == '=')
399 			memmove(boot_command_line, parm + 1, rc);
400 		else
401 			*delim = ' ';		/* replace '\0' with space */
402 	}
403 }
404 
405 static inline int has_ebcdic_char(const char *str)
406 {
407 	int i;
408 
409 	for (i = 0; str[i]; i++)
410 		if (str[i] & 0x80)
411 			return 1;
412 	return 0;
413 }
414 
415 static void __init setup_boot_command_line(void)
416 {
417 	COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
418 	/* convert arch command line to ascii if necessary */
419 	if (has_ebcdic_char(COMMAND_LINE))
420 		EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
421 	/* copy arch command line */
422 	strlcpy(boot_command_line, strstrip(COMMAND_LINE),
423 		ARCH_COMMAND_LINE_SIZE);
424 
425 	/* append IPL PARM data to the boot command line */
426 	if (MACHINE_IS_VM)
427 		append_to_cmdline(append_ipl_vmparm);
428 
429 	append_to_cmdline(append_ipl_scpdata);
430 }
431 
432 /*
433  * Save ipl parameters, clear bss memory, initialize storage keys
434  * and create a kernel NSS at startup if the SAVESYS= parm is defined
435  */
436 void __init startup_init(void)
437 {
438 	reset_tod_clock();
439 	ipl_save_parameters();
440 	rescue_initrd();
441 	clear_bss_section();
442 	init_kernel_storage_key();
443 	lockdep_init();
444 	lockdep_off();
445 	setup_lowcore_early();
446 	setup_facility_list();
447 	detect_machine_type();
448 	ipl_update_parameters();
449 	setup_boot_command_line();
450 	create_kernel_nss();
451 	detect_diag9c();
452 	detect_diag44();
453 	detect_machine_facilities();
454 	setup_topology();
455 	sclp_early_detect();
456 	lockdep_on();
457 }
458