xref: /openbmc/linux/arch/s390/kernel/early.c (revision 5b394b2d)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *    Copyright IBM Corp. 2007, 2009
4  *    Author(s): Hongjie Yang <hongjie@us.ibm.com>,
5  *		 Heiko Carstens <heiko.carstens@de.ibm.com>
6  */
7 
8 #define KMSG_COMPONENT "setup"
9 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
10 
11 #include <linux/compiler.h>
12 #include <linux/init.h>
13 #include <linux/errno.h>
14 #include <linux/string.h>
15 #include <linux/ctype.h>
16 #include <linux/lockdep.h>
17 #include <linux/extable.h>
18 #include <linux/pfn.h>
19 #include <linux/uaccess.h>
20 #include <linux/kernel.h>
21 #include <asm/diag.h>
22 #include <asm/ebcdic.h>
23 #include <asm/ipl.h>
24 #include <asm/lowcore.h>
25 #include <asm/processor.h>
26 #include <asm/sections.h>
27 #include <asm/setup.h>
28 #include <asm/sysinfo.h>
29 #include <asm/cpcmd.h>
30 #include <asm/sclp.h>
31 #include <asm/facility.h>
32 #include "entry.h"
33 
34 static void __init setup_boot_command_line(void);
35 
36 /*
37  * Initialize storage key for kernel pages
38  */
39 static noinline __init void init_kernel_storage_key(void)
40 {
41 #if PAGE_DEFAULT_KEY
42 	unsigned long end_pfn, init_pfn;
43 
44 	end_pfn = PFN_UP(__pa(_end));
45 
46 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
47 		page_set_storage_key(init_pfn << PAGE_SHIFT,
48 				     PAGE_DEFAULT_KEY, 0);
49 #endif
50 }
51 
52 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
53 
54 static noinline __init void detect_machine_type(void)
55 {
56 	struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
57 
58 	/* Check current-configuration-level */
59 	if (stsi(NULL, 0, 0, 0) <= 2) {
60 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
61 		return;
62 	}
63 	/* Get virtual-machine cpu information. */
64 	if (stsi(vmms, 3, 2, 2) || !vmms->count)
65 		return;
66 
67 	/* Running under KVM? If not we assume z/VM */
68 	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
69 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
70 	else
71 		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
72 }
73 
74 /* Remove leading, trailing and double whitespace. */
75 static inline void strim_all(char *str)
76 {
77 	char *s;
78 
79 	s = strim(str);
80 	if (s != str)
81 		memmove(str, s, strlen(s));
82 	while (*str) {
83 		if (!isspace(*str++))
84 			continue;
85 		if (isspace(*str)) {
86 			s = skip_spaces(str);
87 			memmove(str, s, strlen(s) + 1);
88 		}
89 	}
90 }
91 
92 static noinline __init void setup_arch_string(void)
93 {
94 	struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
95 	struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
96 	char mstr[80], hvstr[17];
97 
98 	if (stsi(mach, 1, 1, 1))
99 		return;
100 	EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
101 	EBCASC(mach->type, sizeof(mach->type));
102 	EBCASC(mach->model, sizeof(mach->model));
103 	EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
104 	sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
105 		mach->manufacturer, mach->type,
106 		mach->model, mach->model_capacity);
107 	strim_all(mstr);
108 	if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
109 		EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
110 		sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
111 		strim_all(hvstr);
112 	} else {
113 		sprintf(hvstr, "%s",
114 			MACHINE_IS_LPAR ? "LPAR" :
115 			MACHINE_IS_VM ? "z/VM" :
116 			MACHINE_IS_KVM ? "KVM" : "unknown");
117 	}
118 	dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
119 }
120 
121 static __init void setup_topology(void)
122 {
123 	int max_mnest;
124 
125 	if (!test_facility(11))
126 		return;
127 	S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
128 	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
129 		if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
130 			break;
131 	}
132 	topology_max_mnest = max_mnest;
133 }
134 
135 static void early_pgm_check_handler(void)
136 {
137 	const struct exception_table_entry *fixup;
138 	unsigned long cr0, cr0_new;
139 	unsigned long addr;
140 
141 	addr = S390_lowcore.program_old_psw.addr;
142 	fixup = search_exception_tables(addr);
143 	if (!fixup)
144 		disabled_wait(0);
145 	/* Disable low address protection before storing into lowcore. */
146 	__ctl_store(cr0, 0, 0);
147 	cr0_new = cr0 & ~(1UL << 28);
148 	__ctl_load(cr0_new, 0, 0);
149 	S390_lowcore.program_old_psw.addr = extable_fixup(fixup);
150 	__ctl_load(cr0, 0, 0);
151 }
152 
153 static noinline __init void setup_lowcore_early(void)
154 {
155 	psw_t psw;
156 
157 	psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
158 	psw.addr = (unsigned long) s390_base_ext_handler;
159 	S390_lowcore.external_new_psw = psw;
160 	psw.addr = (unsigned long) s390_base_pgm_handler;
161 	S390_lowcore.program_new_psw = psw;
162 	s390_base_pgm_handler_fn = early_pgm_check_handler;
163 	S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
164 }
165 
166 static noinline __init void setup_facility_list(void)
167 {
168 	stfle(S390_lowcore.stfle_fac_list,
169 	      ARRAY_SIZE(S390_lowcore.stfle_fac_list));
170 	memcpy(S390_lowcore.alt_stfle_fac_list,
171 	       S390_lowcore.stfle_fac_list,
172 	       sizeof(S390_lowcore.alt_stfle_fac_list));
173 	if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
174 		__clear_facility(82, S390_lowcore.alt_stfle_fac_list);
175 }
176 
177 static __init void detect_diag9c(void)
178 {
179 	unsigned int cpu_address;
180 	int rc;
181 
182 	cpu_address = stap();
183 	diag_stat_inc(DIAG_STAT_X09C);
184 	asm volatile(
185 		"	diag	%2,0,0x9c\n"
186 		"0:	la	%0,0\n"
187 		"1:\n"
188 		EX_TABLE(0b,1b)
189 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
190 	if (!rc)
191 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
192 }
193 
194 static __init void detect_diag44(void)
195 {
196 	int rc;
197 
198 	diag_stat_inc(DIAG_STAT_X044);
199 	asm volatile(
200 		"	diag	0,0,0x44\n"
201 		"0:	la	%0,0\n"
202 		"1:\n"
203 		EX_TABLE(0b,1b)
204 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
205 	if (!rc)
206 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
207 }
208 
209 static __init void detect_machine_facilities(void)
210 {
211 	if (test_facility(8)) {
212 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
213 		__ctl_set_bit(0, 23);
214 	}
215 	if (test_facility(78))
216 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
217 	if (test_facility(3))
218 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
219 	if (test_facility(50) && test_facility(73)) {
220 		S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
221 		__ctl_set_bit(0, 55);
222 	}
223 	if (test_facility(51))
224 		S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
225 	if (test_facility(129)) {
226 		S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
227 		__ctl_set_bit(0, 17);
228 	}
229 	if (test_facility(130)) {
230 		S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
231 		__ctl_set_bit(0, 20);
232 	}
233 	if (test_facility(133))
234 		S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
235 	if (test_facility(139) && (tod_clock_base[1] & 0x80)) {
236 		/* Enabled signed clock comparator comparisons */
237 		S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
238 		clock_comparator_max = -1ULL >> 1;
239 		__ctl_set_bit(0, 53);
240 	}
241 }
242 
243 static inline void save_vector_registers(void)
244 {
245 #ifdef CONFIG_CRASH_DUMP
246 	if (test_facility(129))
247 		save_vx_regs(boot_cpu_vector_save_area);
248 #endif
249 }
250 
251 static int __init disable_vector_extension(char *str)
252 {
253 	S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
254 	__ctl_clear_bit(0, 17);
255 	return 0;
256 }
257 early_param("novx", disable_vector_extension);
258 
259 static int __init noexec_setup(char *str)
260 {
261 	bool enabled;
262 	int rc;
263 
264 	rc = kstrtobool(str, &enabled);
265 	if (!rc && !enabled) {
266 		/* Disable no-execute support */
267 		S390_lowcore.machine_flags &= ~MACHINE_FLAG_NX;
268 		__ctl_clear_bit(0, 20);
269 	}
270 	return rc;
271 }
272 early_param("noexec", noexec_setup);
273 
274 static int __init cad_setup(char *str)
275 {
276 	bool enabled;
277 	int rc;
278 
279 	rc = kstrtobool(str, &enabled);
280 	if (!rc && enabled && test_facility(128))
281 		/* Enable problem state CAD. */
282 		__ctl_set_bit(2, 3);
283 	return rc;
284 }
285 early_param("cad", cad_setup);
286 
287 /* Set up boot command line */
288 static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
289 {
290 	char *parm, *delim;
291 	size_t rc, len;
292 
293 	len = strlen(boot_command_line);
294 
295 	delim = boot_command_line + len;	/* '\0' character position */
296 	parm  = boot_command_line + len + 1;	/* append right after '\0' */
297 
298 	rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
299 	if (rc) {
300 		if (*parm == '=')
301 			memmove(boot_command_line, parm + 1, rc);
302 		else
303 			*delim = ' ';		/* replace '\0' with space */
304 	}
305 }
306 
307 static inline int has_ebcdic_char(const char *str)
308 {
309 	int i;
310 
311 	for (i = 0; str[i]; i++)
312 		if (str[i] & 0x80)
313 			return 1;
314 	return 0;
315 }
316 
317 static void __init setup_boot_command_line(void)
318 {
319 	COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
320 	/* convert arch command line to ascii if necessary */
321 	if (has_ebcdic_char(COMMAND_LINE))
322 		EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
323 	/* copy arch command line */
324 	strlcpy(boot_command_line, strstrip(COMMAND_LINE),
325 		ARCH_COMMAND_LINE_SIZE);
326 
327 	/* append IPL PARM data to the boot command line */
328 	if (MACHINE_IS_VM)
329 		append_to_cmdline(append_ipl_vmparm);
330 
331 	append_to_cmdline(append_ipl_scpdata);
332 }
333 
334 static void __init check_image_bootable(void)
335 {
336 	if (!memcmp(EP_STRING, (void *)EP_OFFSET, strlen(EP_STRING)))
337 		return;
338 
339 	sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n");
340 	sclp_early_printk("This image does not contain all parts necessary for starting up. Use\n");
341 	sclp_early_printk("bzImage or arch/s390/boot/compressed/vmlinux instead.\n");
342 	disabled_wait(0xbadb007);
343 }
344 
345 void __init startup_init(void)
346 {
347 	check_image_bootable();
348 	time_early_init();
349 	init_kernel_storage_key();
350 	lockdep_off();
351 	setup_lowcore_early();
352 	setup_facility_list();
353 	detect_machine_type();
354 	setup_arch_string();
355 	ipl_store_parameters();
356 	setup_boot_command_line();
357 	detect_diag9c();
358 	detect_diag44();
359 	detect_machine_facilities();
360 	save_vector_registers();
361 	setup_topology();
362 	sclp_early_detect();
363 	lockdep_on();
364 }
365