xref: /openbmc/linux/arch/s390/kernel/early.c (revision 7dd65feb)
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 
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 	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 	sprintf(defsys_cmd, "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
127 		kernel_nss_name, stext_pfn - 1, stext_pfn, eshared_pfn - 1,
128 		eshared_pfn, end_pfn);
129 
130 #ifdef CONFIG_BLK_DEV_INITRD
131 	if (INITRD_START && INITRD_SIZE) {
132 		sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
133 		einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
134 		min_size = einitrd_pfn << 2;
135 		sprintf(defsys_cmd, "%s EW %.5X-%.5X", defsys_cmd,
136 		sinitrd_pfn, einitrd_pfn);
137 	}
138 #endif
139 
140 	sprintf(defsys_cmd, "%s EW MINSIZE=%.7iK PARMREGS=0-13",
141 		defsys_cmd, min_size);
142 	sprintf(savesys_cmd, "SAVESYS %s \n IPL %s",
143 		kernel_nss_name, kernel_nss_name);
144 
145 	__cpcmd(defsys_cmd, NULL, 0, &response);
146 
147 	if (response != 0) {
148 		pr_err("Defining the Linux kernel NSS failed with rc=%d\n",
149 			response);
150 		kernel_nss_name[0] = '\0';
151 		return;
152 	}
153 
154 	len = strlen(savesys_cmd);
155 	ASCEBC(savesys_cmd, len);
156 	response = savesys_ipl_nss(savesys_cmd, len);
157 
158 	/* On success: response is equal to the command size,
159 	 *	       max SAVESYS_CMD_SIZE
160 	 * On error: response contains the numeric portion of cp error message.
161 	 *	     for SAVESYS it will be >= 263
162 	 *	     for missing privilege class, it will be 1
163 	 */
164 	if (response > SAVESYS_CMD_SIZE || response == 1) {
165 		pr_err("Saving the Linux kernel NSS failed with rc=%d\n",
166 			response);
167 		kernel_nss_name[0] = '\0';
168 		return;
169 	}
170 
171 	/* re-initialize cputime accounting. */
172 	sched_clock_base_cc = get_clock();
173 	S390_lowcore.last_update_clock = sched_clock_base_cc;
174 	S390_lowcore.last_update_timer = 0x7fffffffffffffffULL;
175 	S390_lowcore.user_timer = 0;
176 	S390_lowcore.system_timer = 0;
177 	asm volatile("SPT 0(%0)" : : "a" (&S390_lowcore.last_update_timer));
178 
179 	/* re-setup boot command line with new ipl vm parms */
180 	ipl_update_parameters();
181 	setup_boot_command_line();
182 
183 	ipl_flags = IPL_NSS_VALID;
184 }
185 
186 #else /* CONFIG_SHARED_KERNEL */
187 
188 static inline void create_kernel_nss(void) { }
189 
190 #endif /* CONFIG_SHARED_KERNEL */
191 
192 /*
193  * Clear bss memory
194  */
195 static noinline __init void clear_bss_section(void)
196 {
197 	memset(__bss_start, 0, __bss_stop - __bss_start);
198 }
199 
200 /*
201  * Initialize storage key for kernel pages
202  */
203 static noinline __init void init_kernel_storage_key(void)
204 {
205 	unsigned long end_pfn, init_pfn;
206 
207 	end_pfn = PFN_UP(__pa(&_end));
208 
209 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
210 		page_set_storage_key(init_pfn << PAGE_SHIFT, PAGE_DEFAULT_KEY);
211 }
212 
213 static __initdata struct sysinfo_3_2_2 vmms __aligned(PAGE_SIZE);
214 
215 static noinline __init void detect_machine_type(void)
216 {
217 	/* No VM information? Looks like LPAR */
218 	if (stsi(&vmms, 3, 2, 2) == -ENOSYS)
219 		return;
220 	if (!vmms.count)
221 		return;
222 
223 	/* Running under KVM? If not we assume z/VM */
224 	if (!memcmp(vmms.vm[0].cpi, "\xd2\xe5\xd4", 3))
225 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
226 	else
227 		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
228 }
229 
230 static __init void early_pgm_check_handler(void)
231 {
232 	unsigned long addr;
233 	const struct exception_table_entry *fixup;
234 
235 	addr = S390_lowcore.program_old_psw.addr;
236 	fixup = search_exception_tables(addr & PSW_ADDR_INSN);
237 	if (!fixup)
238 		disabled_wait(0);
239 	S390_lowcore.program_old_psw.addr = fixup->fixup | PSW_ADDR_AMODE;
240 }
241 
242 static noinline __init void setup_lowcore_early(void)
243 {
244 	psw_t psw;
245 
246 	psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
247 	psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
248 	S390_lowcore.external_new_psw = psw;
249 	psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
250 	S390_lowcore.program_new_psw = psw;
251 	s390_base_pgm_handler_fn = early_pgm_check_handler;
252 }
253 
254 static noinline __init void setup_hpage(void)
255 {
256 #ifndef CONFIG_DEBUG_PAGEALLOC
257 	unsigned int facilities;
258 
259 	facilities = stfl();
260 	if (!(facilities & (1UL << 23)) || !(facilities & (1UL << 29)))
261 		return;
262 	S390_lowcore.machine_flags |= MACHINE_FLAG_HPAGE;
263 	__ctl_set_bit(0, 23);
264 #endif
265 }
266 
267 static __init void detect_mvpg(void)
268 {
269 #ifndef CONFIG_64BIT
270 	int rc;
271 
272 	asm volatile(
273 		"	la	0,0\n"
274 		"	mvpg	%2,%2\n"
275 		"0:	la	%0,0\n"
276 		"1:\n"
277 		EX_TABLE(0b,1b)
278 		: "=d" (rc) : "0" (-EOPNOTSUPP), "a" (0) : "memory", "cc", "0");
279 	if (!rc)
280 		S390_lowcore.machine_flags |= MACHINE_FLAG_MVPG;
281 #endif
282 }
283 
284 static __init void detect_ieee(void)
285 {
286 #ifndef CONFIG_64BIT
287 	int rc, tmp;
288 
289 	asm volatile(
290 		"	efpc	%1,0\n"
291 		"0:	la	%0,0\n"
292 		"1:\n"
293 		EX_TABLE(0b,1b)
294 		: "=d" (rc), "=d" (tmp): "0" (-EOPNOTSUPP) : "cc");
295 	if (!rc)
296 		S390_lowcore.machine_flags |= MACHINE_FLAG_IEEE;
297 #endif
298 }
299 
300 static __init void detect_csp(void)
301 {
302 #ifndef CONFIG_64BIT
303 	int rc;
304 
305 	asm volatile(
306 		"	la	0,0\n"
307 		"	la	1,0\n"
308 		"	la	2,4\n"
309 		"	csp	0,2\n"
310 		"0:	la	%0,0\n"
311 		"1:\n"
312 		EX_TABLE(0b,1b)
313 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc", "0", "1", "2");
314 	if (!rc)
315 		S390_lowcore.machine_flags |= MACHINE_FLAG_CSP;
316 #endif
317 }
318 
319 static __init void detect_diag9c(void)
320 {
321 	unsigned int cpu_address;
322 	int rc;
323 
324 	cpu_address = stap();
325 	asm volatile(
326 		"	diag	%2,0,0x9c\n"
327 		"0:	la	%0,0\n"
328 		"1:\n"
329 		EX_TABLE(0b,1b)
330 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
331 	if (!rc)
332 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
333 }
334 
335 static __init void detect_diag44(void)
336 {
337 #ifdef CONFIG_64BIT
338 	int rc;
339 
340 	asm volatile(
341 		"	diag	0,0,0x44\n"
342 		"0:	la	%0,0\n"
343 		"1:\n"
344 		EX_TABLE(0b,1b)
345 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
346 	if (!rc)
347 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
348 #endif
349 }
350 
351 static __init void detect_machine_facilities(void)
352 {
353 #ifdef CONFIG_64BIT
354 	unsigned int facilities;
355 
356 	facilities = stfl();
357 	if (facilities & (1 << 28))
358 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
359 	if (facilities & (1 << 23))
360 		S390_lowcore.machine_flags |= MACHINE_FLAG_PFMF;
361 	if (facilities & (1 << 4))
362 		S390_lowcore.machine_flags |= MACHINE_FLAG_MVCOS;
363 #endif
364 }
365 
366 static __init void rescue_initrd(void)
367 {
368 #ifdef CONFIG_BLK_DEV_INITRD
369 	/*
370 	 * Move the initrd right behind the bss section in case it starts
371 	 * within the bss section. So we don't overwrite it when the bss
372 	 * section gets cleared.
373 	 */
374 	if (!INITRD_START || !INITRD_SIZE)
375 		return;
376 	if (INITRD_START >= (unsigned long) __bss_stop)
377 		return;
378 	memmove(__bss_stop, (void *) INITRD_START, INITRD_SIZE);
379 	INITRD_START = (unsigned long) __bss_stop;
380 #endif
381 }
382 
383 /* Set up boot command line */
384 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
385 {
386 	char *parm, *delim;
387 	size_t rc, len;
388 
389 	len = strlen(boot_command_line);
390 
391 	delim = boot_command_line + len;	/* '\0' character position */
392 	parm  = boot_command_line + len + 1;	/* append right after '\0' */
393 
394 	rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
395 	if (rc) {
396 		if (*parm == '=')
397 			memmove(boot_command_line, parm + 1, rc);
398 		else
399 			*delim = ' ';		/* replace '\0' with space */
400 	}
401 }
402 
403 static void __init setup_boot_command_line(void)
404 {
405 	/* copy arch command line */
406 	strlcpy(boot_command_line, COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
407 
408 	/* append IPL PARM data to the boot command line */
409 	if (MACHINE_IS_VM)
410 		append_to_cmdline(append_ipl_vmparm);
411 
412 	append_to_cmdline(append_ipl_scpdata);
413 }
414 
415 
416 /*
417  * Save ipl parameters, clear bss memory, initialize storage keys
418  * and create a kernel NSS at startup if the SAVESYS= parm is defined
419  */
420 void __init startup_init(void)
421 {
422 	reset_tod_clock();
423 	ipl_save_parameters();
424 	rescue_initrd();
425 	clear_bss_section();
426 	init_kernel_storage_key();
427 	lockdep_init();
428 	lockdep_off();
429 	sort_main_extable();
430 	setup_lowcore_early();
431 	detect_machine_type();
432 	ipl_update_parameters();
433 	setup_boot_command_line();
434 	create_kernel_nss();
435 	detect_mvpg();
436 	detect_ieee();
437 	detect_csp();
438 	detect_diag9c();
439 	detect_diag44();
440 	detect_machine_facilities();
441 	setup_hpage();
442 	sclp_facilities_detect();
443 	detect_memory_layout(memory_chunk);
444 #ifdef CONFIG_DYNAMIC_FTRACE
445 	S390_lowcore.ftrace_func = (unsigned long)ftrace_caller;
446 #endif
447 	lockdep_on();
448 }
449