xref: /linux/arch/s390/kernel/early.c (revision 1553a1c48281243359a9529a10ddb551f3b967ab)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *    Copyright IBM Corp. 2007, 2009
4  *    Author(s): Hongjie Yang <hongjie@us.ibm.com>,
5  */
6 
7 #define KMSG_COMPONENT "setup"
8 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
9 
10 #include <linux/compiler.h>
11 #include <linux/init.h>
12 #include <linux/errno.h>
13 #include <linux/string.h>
14 #include <linux/ctype.h>
15 #include <linux/lockdep.h>
16 #include <linux/extable.h>
17 #include <linux/pfn.h>
18 #include <linux/uaccess.h>
19 #include <linux/kernel.h>
20 #include <asm/asm-extable.h>
21 #include <linux/memblock.h>
22 #include <asm/access-regs.h>
23 #include <asm/diag.h>
24 #include <asm/ebcdic.h>
25 #include <asm/fpu.h>
26 #include <asm/ipl.h>
27 #include <asm/lowcore.h>
28 #include <asm/processor.h>
29 #include <asm/sections.h>
30 #include <asm/setup.h>
31 #include <asm/sysinfo.h>
32 #include <asm/cpcmd.h>
33 #include <asm/sclp.h>
34 #include <asm/facility.h>
35 #include <asm/boot_data.h>
36 #include "entry.h"
37 
38 #define decompressor_handled_param(param)			\
39 static int __init ignore_decompressor_param_##param(char *s)	\
40 {								\
41 	return 0;						\
42 }								\
43 early_param(#param, ignore_decompressor_param_##param)
44 
45 decompressor_handled_param(mem);
46 decompressor_handled_param(vmalloc);
47 decompressor_handled_param(dfltcc);
48 decompressor_handled_param(facilities);
49 decompressor_handled_param(nokaslr);
50 decompressor_handled_param(cmma);
51 #if IS_ENABLED(CONFIG_KVM)
52 decompressor_handled_param(prot_virt);
53 #endif
54 
55 static void __init kasan_early_init(void)
56 {
57 #ifdef CONFIG_KASAN
58 	init_task.kasan_depth = 0;
59 	sclp_early_printk("KernelAddressSanitizer initialized\n");
60 #endif
61 }
62 
63 static void __init reset_tod_clock(void)
64 {
65 	union tod_clock clk;
66 
67 	if (store_tod_clock_ext_cc(&clk) == 0)
68 		return;
69 	/* TOD clock not running. Set the clock to Unix Epoch. */
70 	if (set_tod_clock(TOD_UNIX_EPOCH) || store_tod_clock_ext_cc(&clk))
71 		disabled_wait();
72 
73 	memset(&tod_clock_base, 0, sizeof(tod_clock_base));
74 	tod_clock_base.tod = TOD_UNIX_EPOCH;
75 	S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
76 }
77 
78 /*
79  * Initialize storage key for kernel pages
80  */
81 static noinline __init void init_kernel_storage_key(void)
82 {
83 #if PAGE_DEFAULT_KEY
84 	unsigned long end_pfn, init_pfn;
85 
86 	end_pfn = PFN_UP(__pa(_end));
87 
88 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
89 		page_set_storage_key(init_pfn << PAGE_SHIFT,
90 				     PAGE_DEFAULT_KEY, 0);
91 #endif
92 }
93 
94 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
95 
96 static noinline __init void detect_machine_type(void)
97 {
98 	struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
99 
100 	/* Check current-configuration-level */
101 	if (stsi(NULL, 0, 0, 0) <= 2) {
102 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
103 		return;
104 	}
105 	/* Get virtual-machine cpu information. */
106 	if (stsi(vmms, 3, 2, 2) || !vmms->count)
107 		return;
108 
109 	/* Detect known hypervisors */
110 	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
111 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
112 	else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
113 		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
114 }
115 
116 /* Remove leading, trailing and double whitespace. */
117 static inline void strim_all(char *str)
118 {
119 	char *s;
120 
121 	s = strim(str);
122 	if (s != str)
123 		memmove(str, s, strlen(s));
124 	while (*str) {
125 		if (!isspace(*str++))
126 			continue;
127 		if (isspace(*str)) {
128 			s = skip_spaces(str);
129 			memmove(str, s, strlen(s) + 1);
130 		}
131 	}
132 }
133 
134 static noinline __init void setup_arch_string(void)
135 {
136 	struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
137 	struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
138 	char mstr[80], hvstr[17];
139 
140 	if (stsi(mach, 1, 1, 1))
141 		return;
142 	EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
143 	EBCASC(mach->type, sizeof(mach->type));
144 	EBCASC(mach->model, sizeof(mach->model));
145 	EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
146 	sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
147 		mach->manufacturer, mach->type,
148 		mach->model, mach->model_capacity);
149 	strim_all(mstr);
150 	if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
151 		EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
152 		sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
153 		strim_all(hvstr);
154 	} else {
155 		sprintf(hvstr, "%s",
156 			MACHINE_IS_LPAR ? "LPAR" :
157 			MACHINE_IS_VM ? "z/VM" :
158 			MACHINE_IS_KVM ? "KVM" : "unknown");
159 	}
160 	dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
161 }
162 
163 static __init void setup_topology(void)
164 {
165 	int max_mnest;
166 
167 	if (!test_facility(11))
168 		return;
169 	S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
170 	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
171 		if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
172 			break;
173 	}
174 	topology_max_mnest = max_mnest;
175 }
176 
177 void __do_early_pgm_check(struct pt_regs *regs)
178 {
179 	if (!fixup_exception(regs))
180 		disabled_wait();
181 }
182 
183 static noinline __init void setup_lowcore_early(void)
184 {
185 	psw_t psw;
186 
187 	psw.addr = (unsigned long)early_pgm_check_handler;
188 	psw.mask = PSW_KERNEL_BITS;
189 	S390_lowcore.program_new_psw = psw;
190 	S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
191 }
192 
193 static noinline __init void setup_facility_list(void)
194 {
195 	memcpy(alt_stfle_fac_list, stfle_fac_list, sizeof(alt_stfle_fac_list));
196 	if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
197 		__clear_facility(82, alt_stfle_fac_list);
198 }
199 
200 static __init void detect_diag9c(void)
201 {
202 	unsigned int cpu_address;
203 	int rc;
204 
205 	cpu_address = stap();
206 	diag_stat_inc(DIAG_STAT_X09C);
207 	asm volatile(
208 		"	diag	%2,0,0x9c\n"
209 		"0:	la	%0,0\n"
210 		"1:\n"
211 		EX_TABLE(0b,1b)
212 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
213 	if (!rc)
214 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
215 }
216 
217 static __init void detect_machine_facilities(void)
218 {
219 	if (test_facility(8)) {
220 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
221 		system_ctl_set_bit(0, CR0_EDAT_BIT);
222 	}
223 	if (test_facility(78))
224 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
225 	if (test_facility(3))
226 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
227 	if (test_facility(50) && test_facility(73)) {
228 		S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
229 		system_ctl_set_bit(0, CR0_TRANSACTIONAL_EXECUTION_BIT);
230 	}
231 	if (test_facility(51))
232 		S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
233 	if (test_facility(129))
234 		system_ctl_set_bit(0, CR0_VECTOR_BIT);
235 	if (test_facility(130))
236 		S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
237 	if (test_facility(133))
238 		S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
239 	if (test_facility(139) && (tod_clock_base.tod >> 63)) {
240 		/* Enabled signed clock comparator comparisons */
241 		S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
242 		clock_comparator_max = -1ULL >> 1;
243 		system_ctl_set_bit(0, CR0_CLOCK_COMPARATOR_SIGN_BIT);
244 	}
245 	if (IS_ENABLED(CONFIG_PCI) && test_facility(153)) {
246 		S390_lowcore.machine_flags |= MACHINE_FLAG_PCI_MIO;
247 		/* the control bit is set during PCI initialization */
248 	}
249 	if (test_facility(194))
250 		S390_lowcore.machine_flags |= MACHINE_FLAG_RDP;
251 }
252 
253 static inline void save_vector_registers(void)
254 {
255 #ifdef CONFIG_CRASH_DUMP
256 	if (test_facility(129))
257 		save_vx_regs(boot_cpu_vector_save_area);
258 #endif
259 }
260 
261 static inline void setup_low_address_protection(void)
262 {
263 	system_ctl_set_bit(0, CR0_LOW_ADDRESS_PROTECTION_BIT);
264 }
265 
266 static inline void setup_access_registers(void)
267 {
268 	unsigned int acrs[NUM_ACRS] = { 0 };
269 
270 	restore_access_regs(acrs);
271 }
272 
273 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
274 static void __init setup_boot_command_line(void)
275 {
276 	/* copy arch command line */
277 	strscpy(boot_command_line, early_command_line, COMMAND_LINE_SIZE);
278 }
279 
280 static void __init sort_amode31_extable(void)
281 {
282 	sort_extable(__start_amode31_ex_table, __stop_amode31_ex_table);
283 }
284 
285 void __init startup_init(void)
286 {
287 	kasan_early_init();
288 	reset_tod_clock();
289 	time_early_init();
290 	init_kernel_storage_key();
291 	lockdep_off();
292 	sort_amode31_extable();
293 	setup_lowcore_early();
294 	setup_facility_list();
295 	detect_machine_type();
296 	setup_arch_string();
297 	setup_boot_command_line();
298 	detect_diag9c();
299 	detect_machine_facilities();
300 	save_vector_registers();
301 	setup_topology();
302 	sclp_early_detect();
303 	setup_low_address_protection();
304 	setup_access_registers();
305 	lockdep_on();
306 }
307