xref: /openbmc/linux/arch/s390/kernel/early.c (revision e52a6321)
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 <asm/boot_data.h>
33 #include "entry.h"
34 
35 /*
36  * Initialize storage key for kernel pages
37  */
38 static noinline __init void init_kernel_storage_key(void)
39 {
40 #if PAGE_DEFAULT_KEY
41 	unsigned long end_pfn, init_pfn;
42 
43 	end_pfn = PFN_UP(__pa(_end));
44 
45 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
46 		page_set_storage_key(init_pfn << PAGE_SHIFT,
47 				     PAGE_DEFAULT_KEY, 0);
48 #endif
49 }
50 
51 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
52 
53 static noinline __init void detect_machine_type(void)
54 {
55 	struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
56 
57 	/* Check current-configuration-level */
58 	if (stsi(NULL, 0, 0, 0) <= 2) {
59 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
60 		return;
61 	}
62 	/* Get virtual-machine cpu information. */
63 	if (stsi(vmms, 3, 2, 2) || !vmms->count)
64 		return;
65 
66 	/* Detect known hypervisors */
67 	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
68 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
69 	else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
70 		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
71 }
72 
73 /* Remove leading, trailing and double whitespace. */
74 static inline void strim_all(char *str)
75 {
76 	char *s;
77 
78 	s = strim(str);
79 	if (s != str)
80 		memmove(str, s, strlen(s));
81 	while (*str) {
82 		if (!isspace(*str++))
83 			continue;
84 		if (isspace(*str)) {
85 			s = skip_spaces(str);
86 			memmove(str, s, strlen(s) + 1);
87 		}
88 	}
89 }
90 
91 static noinline __init void setup_arch_string(void)
92 {
93 	struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
94 	struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
95 	char mstr[80], hvstr[17];
96 
97 	if (stsi(mach, 1, 1, 1))
98 		return;
99 	EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
100 	EBCASC(mach->type, sizeof(mach->type));
101 	EBCASC(mach->model, sizeof(mach->model));
102 	EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
103 	sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
104 		mach->manufacturer, mach->type,
105 		mach->model, mach->model_capacity);
106 	strim_all(mstr);
107 	if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
108 		EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
109 		sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
110 		strim_all(hvstr);
111 	} else {
112 		sprintf(hvstr, "%s",
113 			MACHINE_IS_LPAR ? "LPAR" :
114 			MACHINE_IS_VM ? "z/VM" :
115 			MACHINE_IS_KVM ? "KVM" : "unknown");
116 	}
117 	dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
118 }
119 
120 static __init void setup_topology(void)
121 {
122 	int max_mnest;
123 
124 	if (!test_facility(11))
125 		return;
126 	S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
127 	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
128 		if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
129 			break;
130 	}
131 	topology_max_mnest = max_mnest;
132 }
133 
134 static void early_pgm_check_handler(void)
135 {
136 	const struct exception_table_entry *fixup;
137 	unsigned long cr0, cr0_new;
138 	unsigned long addr;
139 
140 	addr = S390_lowcore.program_old_psw.addr;
141 	fixup = s390_search_extables(addr);
142 	if (!fixup)
143 		disabled_wait();
144 	/* Disable low address protection before storing into lowcore. */
145 	__ctl_store(cr0, 0, 0);
146 	cr0_new = cr0 & ~(1UL << 28);
147 	__ctl_load(cr0_new, 0, 0);
148 	S390_lowcore.program_old_psw.addr = extable_fixup(fixup);
149 	__ctl_load(cr0, 0, 0);
150 }
151 
152 static noinline __init void setup_lowcore_early(void)
153 {
154 	psw_t psw;
155 
156 	psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
157 	psw.addr = (unsigned long) s390_base_ext_handler;
158 	S390_lowcore.external_new_psw = psw;
159 	psw.addr = (unsigned long) s390_base_pgm_handler;
160 	S390_lowcore.program_new_psw = psw;
161 	s390_base_pgm_handler_fn = early_pgm_check_handler;
162 	S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
163 }
164 
165 static noinline __init void setup_facility_list(void)
166 {
167 	memcpy(S390_lowcore.alt_stfle_fac_list,
168 	       S390_lowcore.stfle_fac_list,
169 	       sizeof(S390_lowcore.alt_stfle_fac_list));
170 	if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
171 		__clear_facility(82, S390_lowcore.alt_stfle_fac_list);
172 }
173 
174 static __init void detect_diag9c(void)
175 {
176 	unsigned int cpu_address;
177 	int rc;
178 
179 	cpu_address = stap();
180 	diag_stat_inc(DIAG_STAT_X09C);
181 	asm volatile(
182 		"	diag	%2,0,0x9c\n"
183 		"0:	la	%0,0\n"
184 		"1:\n"
185 		EX_TABLE(0b,1b)
186 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
187 	if (!rc)
188 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
189 }
190 
191 static __init void detect_diag44(void)
192 {
193 	int rc;
194 
195 	diag_stat_inc(DIAG_STAT_X044);
196 	asm volatile(
197 		"	diag	0,0,0x44\n"
198 		"0:	la	%0,0\n"
199 		"1:\n"
200 		EX_TABLE(0b,1b)
201 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
202 	if (!rc)
203 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
204 }
205 
206 static __init void detect_machine_facilities(void)
207 {
208 	if (test_facility(8)) {
209 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
210 		__ctl_set_bit(0, 23);
211 	}
212 	if (test_facility(78))
213 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
214 	if (test_facility(3))
215 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
216 	if (test_facility(50) && test_facility(73)) {
217 		S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
218 		__ctl_set_bit(0, 55);
219 	}
220 	if (test_facility(51))
221 		S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
222 	if (test_facility(129)) {
223 		S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
224 		__ctl_set_bit(0, 17);
225 	}
226 	if (test_facility(130)) {
227 		S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
228 		__ctl_set_bit(0, 20);
229 	}
230 	if (test_facility(133))
231 		S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
232 	if (test_facility(139) && (tod_clock_base[1] & 0x80)) {
233 		/* Enabled signed clock comparator comparisons */
234 		S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
235 		clock_comparator_max = -1ULL >> 1;
236 		__ctl_set_bit(0, 53);
237 	}
238 }
239 
240 static inline void save_vector_registers(void)
241 {
242 #ifdef CONFIG_CRASH_DUMP
243 	if (test_facility(129))
244 		save_vx_regs(boot_cpu_vector_save_area);
245 #endif
246 }
247 
248 static int __init disable_vector_extension(char *str)
249 {
250 	S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
251 	__ctl_clear_bit(0, 17);
252 	return 0;
253 }
254 early_param("novx", disable_vector_extension);
255 
256 static int __init noexec_setup(char *str)
257 {
258 	bool enabled;
259 	int rc;
260 
261 	rc = kstrtobool(str, &enabled);
262 	if (!rc && !enabled) {
263 		/* Disable no-execute support */
264 		S390_lowcore.machine_flags &= ~MACHINE_FLAG_NX;
265 		__ctl_clear_bit(0, 20);
266 	}
267 	return rc;
268 }
269 early_param("noexec", noexec_setup);
270 
271 static int __init cad_setup(char *str)
272 {
273 	bool enabled;
274 	int rc;
275 
276 	rc = kstrtobool(str, &enabled);
277 	if (!rc && enabled && test_facility(128))
278 		/* Enable problem state CAD. */
279 		__ctl_set_bit(2, 3);
280 	return rc;
281 }
282 early_param("cad", cad_setup);
283 
284 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
285 static void __init setup_boot_command_line(void)
286 {
287 	/* copy arch command line */
288 	strlcpy(boot_command_line, early_command_line, ARCH_COMMAND_LINE_SIZE);
289 }
290 
291 static void __init check_image_bootable(void)
292 {
293 	if (!memcmp(EP_STRING, (void *)EP_OFFSET, strlen(EP_STRING)))
294 		return;
295 
296 	sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n");
297 	sclp_early_printk("This image does not contain all parts necessary for starting up. Use\n");
298 	sclp_early_printk("bzImage or arch/s390/boot/compressed/vmlinux instead.\n");
299 	disabled_wait();
300 }
301 
302 void __init startup_init(void)
303 {
304 	check_image_bootable();
305 	time_early_init();
306 	init_kernel_storage_key();
307 	lockdep_off();
308 	setup_lowcore_early();
309 	setup_facility_list();
310 	detect_machine_type();
311 	setup_arch_string();
312 	setup_boot_command_line();
313 	detect_diag9c();
314 	detect_diag44();
315 	detect_machine_facilities();
316 	save_vector_registers();
317 	setup_topology();
318 	sclp_early_detect();
319 	lockdep_on();
320 }
321