xref: /openbmc/linux/arch/s390/kernel/early.c (revision b96fc2f3)
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 	"	stmg	6,15,48(15)\n"
68 	"	lgr	14,3\n"
69 	"	sam31\n"
70 	"	diag	2,14,0x8\n"
71 	"	sam64\n"
72 	"	lgr	2,14\n"
73 	"	lmg	6,15,48(15)\n"
74 	"	br	14\n"
75 	"	.size	savesys_ipl_nss, .-savesys_ipl_nss\n"
76 	"	.previous\n");
77 
78 static __initdata char upper_command_line[COMMAND_LINE_SIZE];
79 
80 static noinline __init void create_kernel_nss(void)
81 {
82 	unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
83 #ifdef CONFIG_BLK_DEV_INITRD
84 	unsigned int sinitrd_pfn, einitrd_pfn;
85 #endif
86 	int response;
87 	int hlen;
88 	size_t len;
89 	char *savesys_ptr;
90 	char defsys_cmd[DEFSYS_CMD_SIZE];
91 	char savesys_cmd[SAVESYS_CMD_SIZE];
92 
93 	/* Do nothing if we are not running under VM */
94 	if (!MACHINE_IS_VM)
95 		return;
96 
97 	/* Convert COMMAND_LINE to upper case */
98 	for (i = 0; i < strlen(boot_command_line); i++)
99 		upper_command_line[i] = toupper(boot_command_line[i]);
100 
101 	savesys_ptr = strstr(upper_command_line, "SAVESYS=");
102 
103 	if (!savesys_ptr)
104 		return;
105 
106 	savesys_ptr += 8;    /* Point to the beginning of the NSS name */
107 	for (i = 0; i < NSS_NAME_SIZE; i++) {
108 		if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0')
109 			break;
110 		kernel_nss_name[i] = savesys_ptr[i];
111 	}
112 
113 	stext_pfn = PFN_DOWN(__pa(&_stext));
114 	eshared_pfn = PFN_DOWN(__pa(&_eshared));
115 	end_pfn = PFN_UP(__pa(&_end));
116 	min_size = end_pfn << 2;
117 
118 	hlen = snprintf(defsys_cmd, DEFSYS_CMD_SIZE,
119 			"DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
120 			kernel_nss_name, stext_pfn - 1, stext_pfn,
121 			eshared_pfn - 1, eshared_pfn, end_pfn);
122 
123 #ifdef CONFIG_BLK_DEV_INITRD
124 	if (INITRD_START && INITRD_SIZE) {
125 		sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
126 		einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
127 		min_size = einitrd_pfn << 2;
128 		hlen += snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
129 				 " EW %.5X-%.5X", sinitrd_pfn, einitrd_pfn);
130 	}
131 #endif
132 
133 	snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
134 		 " EW MINSIZE=%.7iK PARMREGS=0-13", min_size);
135 	defsys_cmd[DEFSYS_CMD_SIZE - 1] = '\0';
136 	snprintf(savesys_cmd, SAVESYS_CMD_SIZE, "SAVESYS %s \n IPL %s",
137 		 kernel_nss_name, kernel_nss_name);
138 	savesys_cmd[SAVESYS_CMD_SIZE - 1] = '\0';
139 
140 	__cpcmd(defsys_cmd, NULL, 0, &response);
141 
142 	if (response != 0) {
143 		pr_err("Defining the Linux kernel NSS failed with rc=%d\n",
144 			response);
145 		kernel_nss_name[0] = '\0';
146 		return;
147 	}
148 
149 	len = strlen(savesys_cmd);
150 	ASCEBC(savesys_cmd, len);
151 	response = savesys_ipl_nss(savesys_cmd, len);
152 
153 	/* On success: response is equal to the command size,
154 	 *	       max SAVESYS_CMD_SIZE
155 	 * On error: response contains the numeric portion of cp error message.
156 	 *	     for SAVESYS it will be >= 263
157 	 *	     for missing privilege class, it will be 1
158 	 */
159 	if (response > SAVESYS_CMD_SIZE || response == 1) {
160 		pr_err("Saving the Linux kernel NSS failed with rc=%d\n",
161 			response);
162 		kernel_nss_name[0] = '\0';
163 		return;
164 	}
165 
166 	/* re-initialize cputime accounting. */
167 	sched_clock_base_cc = get_tod_clock();
168 	S390_lowcore.last_update_clock = sched_clock_base_cc;
169 	S390_lowcore.last_update_timer = 0x7fffffffffffffffULL;
170 	S390_lowcore.user_timer = 0;
171 	S390_lowcore.system_timer = 0;
172 	asm volatile("SPT 0(%0)" : : "a" (&S390_lowcore.last_update_timer));
173 
174 	/* re-setup boot command line with new ipl vm parms */
175 	ipl_update_parameters();
176 	setup_boot_command_line();
177 
178 	ipl_flags = IPL_NSS_VALID;
179 }
180 
181 #else /* CONFIG_SHARED_KERNEL */
182 
183 static inline void create_kernel_nss(void) { }
184 
185 #endif /* CONFIG_SHARED_KERNEL */
186 
187 /*
188  * Clear bss memory
189  */
190 static noinline __init void clear_bss_section(void)
191 {
192 	memset(__bss_start, 0, __bss_stop - __bss_start);
193 }
194 
195 /*
196  * Initialize storage key for kernel pages
197  */
198 static noinline __init void init_kernel_storage_key(void)
199 {
200 #if PAGE_DEFAULT_KEY
201 	unsigned long end_pfn, init_pfn;
202 
203 	end_pfn = PFN_UP(__pa(&_end));
204 
205 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
206 		page_set_storage_key(init_pfn << PAGE_SHIFT,
207 				     PAGE_DEFAULT_KEY, 0);
208 #endif
209 }
210 
211 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
212 
213 static noinline __init void detect_machine_type(void)
214 {
215 	struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
216 
217 	/* Check current-configuration-level */
218 	if (stsi(NULL, 0, 0, 0) <= 2) {
219 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
220 		return;
221 	}
222 	/* Get virtual-machine cpu information. */
223 	if (stsi(vmms, 3, 2, 2) || !vmms->count)
224 		return;
225 
226 	/* Running under KVM? If not we assume z/VM */
227 	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
228 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
229 	else
230 		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
231 }
232 
233 static __init void setup_topology(void)
234 {
235 	int max_mnest;
236 
237 	if (!test_facility(11))
238 		return;
239 	S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
240 	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
241 		if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
242 			break;
243 	}
244 	topology_max_mnest = max_mnest;
245 }
246 
247 static void early_pgm_check_handler(void)
248 {
249 	const struct exception_table_entry *fixup;
250 	unsigned long cr0, cr0_new;
251 	unsigned long addr;
252 
253 	addr = S390_lowcore.program_old_psw.addr;
254 	fixup = search_exception_tables(addr & PSW_ADDR_INSN);
255 	if (!fixup)
256 		disabled_wait(0);
257 	/* Disable low address protection before storing into lowcore. */
258 	__ctl_store(cr0, 0, 0);
259 	cr0_new = cr0 & ~(1UL << 28);
260 	__ctl_load(cr0_new, 0, 0);
261 	S390_lowcore.program_old_psw.addr = extable_fixup(fixup)|PSW_ADDR_AMODE;
262 	__ctl_load(cr0, 0, 0);
263 }
264 
265 static noinline __init void setup_lowcore_early(void)
266 {
267 	psw_t psw;
268 
269 	psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
270 	psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
271 	S390_lowcore.external_new_psw = psw;
272 	psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
273 	S390_lowcore.program_new_psw = psw;
274 	s390_base_pgm_handler_fn = early_pgm_check_handler;
275 }
276 
277 static noinline __init void setup_facility_list(void)
278 {
279 	stfle(S390_lowcore.stfle_fac_list,
280 	      ARRAY_SIZE(S390_lowcore.stfle_fac_list));
281 }
282 
283 static __init void detect_diag9c(void)
284 {
285 	unsigned int cpu_address;
286 	int rc;
287 
288 	cpu_address = stap();
289 	asm volatile(
290 		"	diag	%2,0,0x9c\n"
291 		"0:	la	%0,0\n"
292 		"1:\n"
293 		EX_TABLE(0b,1b)
294 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
295 	if (!rc)
296 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
297 }
298 
299 static __init void detect_diag44(void)
300 {
301 	int rc;
302 
303 	asm volatile(
304 		"	diag	0,0,0x44\n"
305 		"0:	la	%0,0\n"
306 		"1:\n"
307 		EX_TABLE(0b,1b)
308 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
309 	if (!rc)
310 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
311 }
312 
313 static __init void detect_machine_facilities(void)
314 {
315 	if (test_facility(8)) {
316 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
317 		__ctl_set_bit(0, 23);
318 	}
319 	if (test_facility(78))
320 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
321 	if (test_facility(3))
322 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
323 	if (test_facility(40))
324 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPP;
325 	if (test_facility(50) && test_facility(73))
326 		S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
327 	if (test_facility(51))
328 		S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
329 	if (test_facility(129))
330 		S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
331 }
332 
333 static int __init cad_setup(char *str)
334 {
335 	int val;
336 
337 	get_option(&str, &val);
338 	if (val && test_facility(128))
339 		S390_lowcore.machine_flags |= MACHINE_FLAG_CAD;
340 	return 0;
341 }
342 early_param("cad", cad_setup);
343 
344 static int __init cad_init(void)
345 {
346 	if (MACHINE_HAS_CAD)
347 		/* Enable problem state CAD. */
348 		__ctl_set_bit(2, 3);
349 	return 0;
350 }
351 early_initcall(cad_init);
352 
353 static __init void rescue_initrd(void)
354 {
355 #ifdef CONFIG_BLK_DEV_INITRD
356 	unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
357 	/*
358 	 * Just like in case of IPL from VM reader we make sure there is a
359 	 * gap of 4MB between end of kernel and start of initrd.
360 	 * That way we can also be sure that saving an NSS will succeed,
361 	 * which however only requires different segments.
362 	 */
363 	if (!INITRD_START || !INITRD_SIZE)
364 		return;
365 	if (INITRD_START >= min_initrd_addr)
366 		return;
367 	memmove((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
368 	INITRD_START = min_initrd_addr;
369 #endif
370 }
371 
372 /* Set up boot command line */
373 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
374 {
375 	char *parm, *delim;
376 	size_t rc, len;
377 
378 	len = strlen(boot_command_line);
379 
380 	delim = boot_command_line + len;	/* '\0' character position */
381 	parm  = boot_command_line + len + 1;	/* append right after '\0' */
382 
383 	rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
384 	if (rc) {
385 		if (*parm == '=')
386 			memmove(boot_command_line, parm + 1, rc);
387 		else
388 			*delim = ' ';		/* replace '\0' with space */
389 	}
390 }
391 
392 static inline int has_ebcdic_char(const char *str)
393 {
394 	int i;
395 
396 	for (i = 0; str[i]; i++)
397 		if (str[i] & 0x80)
398 			return 1;
399 	return 0;
400 }
401 
402 static void __init setup_boot_command_line(void)
403 {
404 	COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
405 	/* convert arch command line to ascii if necessary */
406 	if (has_ebcdic_char(COMMAND_LINE))
407 		EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
408 	/* copy arch command line */
409 	strlcpy(boot_command_line, strstrip(COMMAND_LINE),
410 		ARCH_COMMAND_LINE_SIZE);
411 
412 	/* append IPL PARM data to the boot command line */
413 	if (MACHINE_IS_VM)
414 		append_to_cmdline(append_ipl_vmparm);
415 
416 	append_to_cmdline(append_ipl_scpdata);
417 }
418 
419 /*
420  * Save ipl parameters, clear bss memory, initialize storage keys
421  * and create a kernel NSS at startup if the SAVESYS= parm is defined
422  */
423 void __init startup_init(void)
424 {
425 	reset_tod_clock();
426 	ipl_save_parameters();
427 	rescue_initrd();
428 	clear_bss_section();
429 	init_kernel_storage_key();
430 	lockdep_init();
431 	lockdep_off();
432 	setup_lowcore_early();
433 	setup_facility_list();
434 	detect_machine_type();
435 	ipl_update_parameters();
436 	setup_boot_command_line();
437 	create_kernel_nss();
438 	detect_diag9c();
439 	detect_diag44();
440 	detect_machine_facilities();
441 	setup_topology();
442 	sclp_early_detect();
443 	lockdep_on();
444 }
445