xref: /openbmc/linux/arch/s390/kernel/early.c (revision f519f0be)
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 <asm/pci_insn.h>
34 #include "entry.h"
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 	/* Detect known hypervisors */
68 	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
69 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
70 	else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
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 = s390_search_extables(addr);
143 	if (!fixup)
144 		disabled_wait();
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 	memcpy(S390_lowcore.alt_stfle_fac_list,
169 	       S390_lowcore.stfle_fac_list,
170 	       sizeof(S390_lowcore.alt_stfle_fac_list));
171 	if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
172 		__clear_facility(82, S390_lowcore.alt_stfle_fac_list);
173 }
174 
175 static __init void detect_diag9c(void)
176 {
177 	unsigned int cpu_address;
178 	int rc;
179 
180 	cpu_address = stap();
181 	diag_stat_inc(DIAG_STAT_X09C);
182 	asm volatile(
183 		"	diag	%2,0,0x9c\n"
184 		"0:	la	%0,0\n"
185 		"1:\n"
186 		EX_TABLE(0b,1b)
187 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
188 	if (!rc)
189 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
190 }
191 
192 static __init void detect_diag44(void)
193 {
194 	int rc;
195 
196 	diag_stat_inc(DIAG_STAT_X044);
197 	asm volatile(
198 		"	diag	0,0,0x44\n"
199 		"0:	la	%0,0\n"
200 		"1:\n"
201 		EX_TABLE(0b,1b)
202 		: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
203 	if (!rc)
204 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
205 }
206 
207 static __init void detect_machine_facilities(void)
208 {
209 	if (test_facility(8)) {
210 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
211 		__ctl_set_bit(0, 23);
212 	}
213 	if (test_facility(78))
214 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
215 	if (test_facility(3))
216 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
217 	if (test_facility(50) && test_facility(73)) {
218 		S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
219 		__ctl_set_bit(0, 55);
220 	}
221 	if (test_facility(51))
222 		S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
223 	if (test_facility(129)) {
224 		S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
225 		__ctl_set_bit(0, 17);
226 	}
227 	if (test_facility(130)) {
228 		S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
229 		__ctl_set_bit(0, 20);
230 	}
231 	if (test_facility(133))
232 		S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
233 	if (test_facility(139) && (tod_clock_base[1] & 0x80)) {
234 		/* Enabled signed clock comparator comparisons */
235 		S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
236 		clock_comparator_max = -1ULL >> 1;
237 		__ctl_set_bit(0, 53);
238 	}
239 	enable_mio_ctl();
240 }
241 
242 static inline void save_vector_registers(void)
243 {
244 #ifdef CONFIG_CRASH_DUMP
245 	if (test_facility(129))
246 		save_vx_regs(boot_cpu_vector_save_area);
247 #endif
248 }
249 
250 static int __init disable_vector_extension(char *str)
251 {
252 	S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
253 	__ctl_clear_bit(0, 17);
254 	return 0;
255 }
256 early_param("novx", disable_vector_extension);
257 
258 static int __init noexec_setup(char *str)
259 {
260 	bool enabled;
261 	int rc;
262 
263 	rc = kstrtobool(str, &enabled);
264 	if (!rc && !enabled) {
265 		/* Disable no-execute support */
266 		S390_lowcore.machine_flags &= ~MACHINE_FLAG_NX;
267 		__ctl_clear_bit(0, 20);
268 	}
269 	return rc;
270 }
271 early_param("noexec", noexec_setup);
272 
273 static int __init cad_setup(char *str)
274 {
275 	bool enabled;
276 	int rc;
277 
278 	rc = kstrtobool(str, &enabled);
279 	if (!rc && enabled && test_facility(128))
280 		/* Enable problem state CAD. */
281 		__ctl_set_bit(2, 3);
282 	return rc;
283 }
284 early_param("cad", cad_setup);
285 
286 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
287 static void __init setup_boot_command_line(void)
288 {
289 	/* copy arch command line */
290 	strlcpy(boot_command_line, early_command_line, ARCH_COMMAND_LINE_SIZE);
291 }
292 
293 static void __init check_image_bootable(void)
294 {
295 	if (!memcmp(EP_STRING, (void *)EP_OFFSET, strlen(EP_STRING)))
296 		return;
297 
298 	sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n");
299 	sclp_early_printk("This image does not contain all parts necessary for starting up. Use\n");
300 	sclp_early_printk("bzImage or arch/s390/boot/compressed/vmlinux instead.\n");
301 	disabled_wait();
302 }
303 
304 void __init startup_init(void)
305 {
306 	check_image_bootable();
307 	time_early_init();
308 	init_kernel_storage_key();
309 	lockdep_off();
310 	setup_lowcore_early();
311 	setup_facility_list();
312 	detect_machine_type();
313 	setup_arch_string();
314 	setup_boot_command_line();
315 	detect_diag9c();
316 	detect_diag44();
317 	detect_machine_facilities();
318 	save_vector_registers();
319 	setup_topology();
320 	sclp_early_detect();
321 	lockdep_on();
322 }
323