xref: /openbmc/linux/arch/s390/kernel/early.c (revision 82ced6fd)
1 /*
2  *  arch/s390/kernel/early.c
3  *
4  *    Copyright IBM Corp. 2007
5  *    Author(s): Hongjie Yang <hongjie@us.ibm.com>,
6  *		 Heiko Carstens <heiko.carstens@de.ibm.com>
7  */
8 
9 #include <linux/compiler.h>
10 #include <linux/init.h>
11 #include <linux/errno.h>
12 #include <linux/string.h>
13 #include <linux/ctype.h>
14 #include <linux/lockdep.h>
15 #include <linux/module.h>
16 #include <linux/pfn.h>
17 #include <linux/uaccess.h>
18 #include <asm/ebcdic.h>
19 #include <asm/ipl.h>
20 #include <asm/lowcore.h>
21 #include <asm/processor.h>
22 #include <asm/sections.h>
23 #include <asm/setup.h>
24 #include <asm/sysinfo.h>
25 #include <asm/cpcmd.h>
26 #include <asm/sclp.h>
27 #include "entry.h"
28 
29 /*
30  * Create a Kernel NSS if the SAVESYS= parameter is defined
31  */
32 #define DEFSYS_CMD_SIZE		128
33 #define SAVESYS_CMD_SIZE	32
34 
35 char kernel_nss_name[NSS_NAME_SIZE + 1];
36 
37 static unsigned long machine_flags;
38 
39 static void __init setup_boot_command_line(void);
40 
41 /*
42  * Get the TOD clock running.
43  */
44 static void __init reset_tod_clock(void)
45 {
46 	u64 time;
47 
48 	if (store_clock(&time) == 0)
49 		return;
50 	/* TOD clock not running. Set the clock to Unix Epoch. */
51 	if (set_clock(TOD_UNIX_EPOCH) != 0 || store_clock(&time) != 0)
52 		disabled_wait(0);
53 
54 	sched_clock_base_cc = TOD_UNIX_EPOCH;
55 }
56 
57 #ifdef CONFIG_SHARED_KERNEL
58 int __init savesys_ipl_nss(char *cmd, const int cmdlen);
59 
60 asm(
61 	"	.section .init.text,\"ax\",@progbits\n"
62 	"	.align	4\n"
63 	"	.type	savesys_ipl_nss, @function\n"
64 	"savesys_ipl_nss:\n"
65 #ifdef CONFIG_64BIT
66 	"	stmg	6,15,48(15)\n"
67 	"	lgr	14,3\n"
68 	"	sam31\n"
69 	"	diag	2,14,0x8\n"
70 	"	sam64\n"
71 	"	lgr	2,14\n"
72 	"	lmg	6,15,48(15)\n"
73 #else
74 	"	stm	6,15,24(15)\n"
75 	"	lr	14,3\n"
76 	"	diag	2,14,0x8\n"
77 	"	lr	2,14\n"
78 	"	lm	6,15,24(15)\n"
79 #endif
80 	"	br	14\n"
81 	"	.size	savesys_ipl_nss, .-savesys_ipl_nss\n");
82 
83 static noinline __init void create_kernel_nss(void)
84 {
85 	unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
86 #ifdef CONFIG_BLK_DEV_INITRD
87 	unsigned int sinitrd_pfn, einitrd_pfn;
88 #endif
89 	int response;
90 	size_t len;
91 	char *savesys_ptr;
92 	char upper_command_line[COMMAND_LINE_SIZE];
93 	char defsys_cmd[DEFSYS_CMD_SIZE];
94 	char savesys_cmd[SAVESYS_CMD_SIZE];
95 
96 	/* Do nothing if we are not running under VM */
97 	if (!MACHINE_IS_VM)
98 		return;
99 
100 	/* Convert COMMAND_LINE to upper case */
101 	for (i = 0; i < strlen(boot_command_line); i++)
102 		upper_command_line[i] = toupper(boot_command_line[i]);
103 
104 	savesys_ptr = strstr(upper_command_line, "SAVESYS=");
105 
106 	if (!savesys_ptr)
107 		return;
108 
109 	savesys_ptr += 8;    /* Point to the beginning of the NSS name */
110 	for (i = 0; i < NSS_NAME_SIZE; i++) {
111 		if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0')
112 			break;
113 		kernel_nss_name[i] = savesys_ptr[i];
114 	}
115 
116 	stext_pfn = PFN_DOWN(__pa(&_stext));
117 	eshared_pfn = PFN_DOWN(__pa(&_eshared));
118 	end_pfn = PFN_UP(__pa(&_end));
119 	min_size = end_pfn << 2;
120 
121 	sprintf(defsys_cmd, "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
122 		kernel_nss_name, stext_pfn - 1, stext_pfn, eshared_pfn - 1,
123 		eshared_pfn, end_pfn);
124 
125 #ifdef CONFIG_BLK_DEV_INITRD
126 	if (INITRD_START && INITRD_SIZE) {
127 		sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
128 		einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
129 		min_size = einitrd_pfn << 2;
130 		sprintf(defsys_cmd, "%s EW %.5X-%.5X", defsys_cmd,
131 		sinitrd_pfn, einitrd_pfn);
132 	}
133 #endif
134 
135 	sprintf(defsys_cmd, "%s EW MINSIZE=%.7iK PARMREGS=0-13",
136 		defsys_cmd, min_size);
137 	sprintf(savesys_cmd, "SAVESYS %s \n IPL %s",
138 		kernel_nss_name, kernel_nss_name);
139 
140 	__cpcmd(defsys_cmd, NULL, 0, &response);
141 
142 	if (response != 0) {
143 		kernel_nss_name[0] = '\0';
144 		return;
145 	}
146 
147 	len = strlen(savesys_cmd);
148 	ASCEBC(savesys_cmd, len);
149 	response = savesys_ipl_nss(savesys_cmd, len);
150 
151 	/* On success: response is equal to the command size,
152 	 *	       max SAVESYS_CMD_SIZE
153 	 * On error: response contains the numeric portion of cp error message.
154 	 *	     for SAVESYS it will be >= 263
155 	 */
156 	if (response > SAVESYS_CMD_SIZE) {
157 		kernel_nss_name[0] = '\0';
158 		return;
159 	}
160 
161 	/* re-setup boot command line with new ipl vm parms */
162 	ipl_update_parameters();
163 	setup_boot_command_line();
164 
165 	ipl_flags = IPL_NSS_VALID;
166 }
167 
168 #else /* CONFIG_SHARED_KERNEL */
169 
170 static inline void create_kernel_nss(void) { }
171 
172 #endif /* CONFIG_SHARED_KERNEL */
173 
174 /*
175  * Clear bss memory
176  */
177 static noinline __init void clear_bss_section(void)
178 {
179 	memset(__bss_start, 0, __bss_stop - __bss_start);
180 }
181 
182 /*
183  * Initialize storage key for kernel pages
184  */
185 static noinline __init void init_kernel_storage_key(void)
186 {
187 	unsigned long end_pfn, init_pfn;
188 
189 	end_pfn = PFN_UP(__pa(&_end));
190 
191 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
192 		page_set_storage_key(init_pfn << PAGE_SHIFT, PAGE_DEFAULT_KEY);
193 }
194 
195 static __initdata struct sysinfo_3_2_2 vmms __aligned(PAGE_SIZE);
196 
197 static noinline __init void detect_machine_type(void)
198 {
199 	/* No VM information? Looks like LPAR */
200 	if (stsi(&vmms, 3, 2, 2) == -ENOSYS)
201 		return;
202 	if (!vmms.count)
203 		return;
204 
205 	/* Running under KVM? If not we assume z/VM */
206 	if (!memcmp(vmms.vm[0].cpi, "\xd2\xe5\xd4", 3))
207 		machine_flags |= MACHINE_FLAG_KVM;
208 	else
209 		machine_flags |= MACHINE_FLAG_VM;
210 }
211 
212 static __init void early_pgm_check_handler(void)
213 {
214 	unsigned long addr;
215 	const struct exception_table_entry *fixup;
216 
217 	addr = S390_lowcore.program_old_psw.addr;
218 	fixup = search_exception_tables(addr & PSW_ADDR_INSN);
219 	if (!fixup)
220 		disabled_wait(0);
221 	S390_lowcore.program_old_psw.addr = fixup->fixup | PSW_ADDR_AMODE;
222 }
223 
224 static noinline __init void setup_lowcore_early(void)
225 {
226 	psw_t psw;
227 
228 	psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
229 	psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
230 	S390_lowcore.external_new_psw = psw;
231 	psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
232 	S390_lowcore.program_new_psw = psw;
233 	s390_base_pgm_handler_fn = early_pgm_check_handler;
234 }
235 
236 static noinline __init void setup_hpage(void)
237 {
238 #ifndef CONFIG_DEBUG_PAGEALLOC
239 	unsigned int facilities;
240 
241 	facilities = stfl();
242 	if (!(facilities & (1UL << 23)) || !(facilities & (1UL << 29)))
243 		return;
244 	machine_flags |= MACHINE_FLAG_HPAGE;
245 	__ctl_set_bit(0, 23);
246 #endif
247 }
248 
249 static __init void detect_mvpg(void)
250 {
251 #ifndef CONFIG_64BIT
252 	int rc;
253 
254 	asm volatile(
255 		"	la	0,0\n"
256 		"	mvpg	%2,%2\n"
257 		"0:	la	%0,0\n"
258 		"1:\n"
259 		EX_TABLE(0b,1b)
260 		: "=d" (rc) : "0" (-EOPNOTSUPP), "a" (0) : "memory", "cc", "0");
261 	if (!rc)
262 		machine_flags |= MACHINE_FLAG_MVPG;
263 #endif
264 }
265 
266 static __init void detect_ieee(void)
267 {
268 #ifndef CONFIG_64BIT
269 	int rc, tmp;
270 
271 	asm volatile(
272 		"	efpc	%1,0\n"
273 		"0:	la	%0,0\n"
274 		"1:\n"
275 		EX_TABLE(0b,1b)
276 		: "=d" (rc), "=d" (tmp): "0" (-EOPNOTSUPP) : "cc");
277 	if (!rc)
278 		machine_flags |= MACHINE_FLAG_IEEE;
279 #endif
280 }
281 
282 static __init void detect_csp(void)
283 {
284 #ifndef CONFIG_64BIT
285 	int rc;
286 
287 	asm volatile(
288 		"	la	0,0\n"
289 		"	la	1,0\n"
290 		"	la	2,4\n"
291 		"	csp	0,2\n"
292 		"0:	la	%0,0\n"
293 		"1:\n"
294 		EX_TABLE(0b,1b)
295 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc", "0", "1", "2");
296 	if (!rc)
297 		machine_flags |= MACHINE_FLAG_CSP;
298 #endif
299 }
300 
301 static __init void detect_diag9c(void)
302 {
303 	unsigned int cpu_address;
304 	int rc;
305 
306 	cpu_address = stap();
307 	asm volatile(
308 		"	diag	%2,0,0x9c\n"
309 		"0:	la	%0,0\n"
310 		"1:\n"
311 		EX_TABLE(0b,1b)
312 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
313 	if (!rc)
314 		machine_flags |= MACHINE_FLAG_DIAG9C;
315 }
316 
317 static __init void detect_diag44(void)
318 {
319 #ifdef CONFIG_64BIT
320 	int rc;
321 
322 	asm volatile(
323 		"	diag	0,0,0x44\n"
324 		"0:	la	%0,0\n"
325 		"1:\n"
326 		EX_TABLE(0b,1b)
327 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
328 	if (!rc)
329 		machine_flags |= MACHINE_FLAG_DIAG44;
330 #endif
331 }
332 
333 static __init void detect_machine_facilities(void)
334 {
335 #ifdef CONFIG_64BIT
336 	unsigned int facilities;
337 
338 	facilities = stfl();
339 	if (facilities & (1 << 28))
340 		machine_flags |= MACHINE_FLAG_IDTE;
341 	if (facilities & (1 << 23))
342 		machine_flags |= MACHINE_FLAG_PFMF;
343 	if (facilities & (1 << 4))
344 		machine_flags |= MACHINE_FLAG_MVCOS;
345 #endif
346 }
347 
348 static __init void rescue_initrd(void)
349 {
350 #ifdef CONFIG_BLK_DEV_INITRD
351 	/*
352 	 * Move the initrd right behind the bss section in case it starts
353 	 * within the bss section. So we don't overwrite it when the bss
354 	 * section gets cleared.
355 	 */
356 	if (!INITRD_START || !INITRD_SIZE)
357 		return;
358 	if (INITRD_START >= (unsigned long) __bss_stop)
359 		return;
360 	memmove(__bss_stop, (void *) INITRD_START, INITRD_SIZE);
361 	INITRD_START = (unsigned long) __bss_stop;
362 #endif
363 }
364 
365 /* Set up boot command line */
366 static void __init setup_boot_command_line(void)
367 {
368 	char *parm = NULL;
369 
370 	/* copy arch command line */
371 	strlcpy(boot_command_line, COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
372 
373 	/* append IPL PARM data to the boot command line */
374 	if (MACHINE_IS_VM) {
375 		parm = boot_command_line + strlen(boot_command_line);
376 		*parm++ = ' ';
377 		get_ipl_vmparm(parm);
378 		if (parm[0] == '=')
379 			memmove(boot_command_line, parm + 1, strlen(parm));
380 	}
381 }
382 
383 
384 /*
385  * Save ipl parameters, clear bss memory, initialize storage keys
386  * and create a kernel NSS at startup if the SAVESYS= parm is defined
387  */
388 void __init startup_init(void)
389 {
390 	reset_tod_clock();
391 	ipl_save_parameters();
392 	rescue_initrd();
393 	clear_bss_section();
394 	init_kernel_storage_key();
395 	lockdep_init();
396 	lockdep_off();
397 	sort_main_extable();
398 	setup_lowcore_early();
399 	detect_machine_type();
400 	ipl_update_parameters();
401 	setup_boot_command_line();
402 	create_kernel_nss();
403 	detect_mvpg();
404 	detect_ieee();
405 	detect_csp();
406 	detect_diag9c();
407 	detect_diag44();
408 	detect_machine_facilities();
409 	setup_hpage();
410 	sclp_facilities_detect();
411 	detect_memory_layout(memory_chunk);
412 	S390_lowcore.machine_flags = machine_flags;
413 	lockdep_on();
414 }
415