xref: /linux/arch/s390/kernel/early.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
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/sched/debug.h>
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/asm-extable.h>
22 #include <linux/memblock.h>
23 #include <asm/access-regs.h>
24 #include <asm/diag.h>
25 #include <asm/ebcdic.h>
26 #include <asm/fpu.h>
27 #include <asm/ipl.h>
28 #include <asm/lowcore.h>
29 #include <asm/processor.h>
30 #include <asm/sections.h>
31 #include <asm/setup.h>
32 #include <asm/sysinfo.h>
33 #include <asm/cpcmd.h>
34 #include <asm/sclp.h>
35 #include <asm/facility.h>
36 #include <asm/boot_data.h>
37 #include "entry.h"
38 
39 #define decompressor_handled_param(param)			\
40 static int __init ignore_decompressor_param_##param(char *s)	\
41 {								\
42 	return 0;						\
43 }								\
44 early_param(#param, ignore_decompressor_param_##param)
45 
46 decompressor_handled_param(mem);
47 decompressor_handled_param(vmalloc);
48 decompressor_handled_param(dfltcc);
49 decompressor_handled_param(facilities);
50 decompressor_handled_param(nokaslr);
51 decompressor_handled_param(cmma);
52 decompressor_handled_param(relocate_lowcore);
53 #if IS_ENABLED(CONFIG_KVM)
54 decompressor_handled_param(prot_virt);
55 #endif
56 
57 static void __init kasan_early_init(void)
58 {
59 #ifdef CONFIG_KASAN
60 	init_task.kasan_depth = 0;
61 	sclp_early_printk("KernelAddressSanitizer initialized\n");
62 #endif
63 }
64 
65 static void __init reset_tod_clock(void)
66 {
67 	union tod_clock clk;
68 
69 	if (store_tod_clock_ext_cc(&clk) == 0)
70 		return;
71 	/* TOD clock not running. Set the clock to Unix Epoch. */
72 	if (set_tod_clock(TOD_UNIX_EPOCH) || store_tod_clock_ext_cc(&clk))
73 		disabled_wait();
74 
75 	memset(&tod_clock_base, 0, sizeof(tod_clock_base));
76 	tod_clock_base.tod = TOD_UNIX_EPOCH;
77 	get_lowcore()->last_update_clock = TOD_UNIX_EPOCH;
78 }
79 
80 /*
81  * Initialize storage key for kernel pages
82  */
83 static noinline __init void init_kernel_storage_key(void)
84 {
85 #if PAGE_DEFAULT_KEY
86 	unsigned long end_pfn, init_pfn;
87 
88 	end_pfn = PFN_UP(__pa(_end));
89 
90 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
91 		page_set_storage_key(init_pfn << PAGE_SHIFT,
92 				     PAGE_DEFAULT_KEY, 0);
93 #endif
94 }
95 
96 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
97 
98 static noinline __init void detect_machine_type(void)
99 {
100 	struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
101 
102 	/* Check current-configuration-level */
103 	if (stsi(NULL, 0, 0, 0) <= 2) {
104 		get_lowcore()->machine_flags |= MACHINE_FLAG_LPAR;
105 		return;
106 	}
107 	/* Get virtual-machine cpu information. */
108 	if (stsi(vmms, 3, 2, 2) || !vmms->count)
109 		return;
110 
111 	/* Detect known hypervisors */
112 	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
113 		get_lowcore()->machine_flags |= MACHINE_FLAG_KVM;
114 	else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
115 		get_lowcore()->machine_flags |= MACHINE_FLAG_VM;
116 }
117 
118 /* Remove leading, trailing and double whitespace. */
119 static inline void strim_all(char *str)
120 {
121 	char *s;
122 
123 	s = strim(str);
124 	if (s != str)
125 		memmove(str, s, strlen(s));
126 	while (*str) {
127 		if (!isspace(*str++))
128 			continue;
129 		if (isspace(*str)) {
130 			s = skip_spaces(str);
131 			memmove(str, s, strlen(s) + 1);
132 		}
133 	}
134 }
135 
136 static noinline __init void setup_arch_string(void)
137 {
138 	struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
139 	struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
140 	char mstr[80], hvstr[17];
141 
142 	if (stsi(mach, 1, 1, 1))
143 		return;
144 	EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
145 	EBCASC(mach->type, sizeof(mach->type));
146 	EBCASC(mach->model, sizeof(mach->model));
147 	EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
148 	sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
149 		mach->manufacturer, mach->type,
150 		mach->model, mach->model_capacity);
151 	strim_all(mstr);
152 	if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
153 		EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
154 		sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
155 		strim_all(hvstr);
156 	} else {
157 		sprintf(hvstr, "%s",
158 			MACHINE_IS_LPAR ? "LPAR" :
159 			MACHINE_IS_VM ? "z/VM" :
160 			MACHINE_IS_KVM ? "KVM" : "unknown");
161 	}
162 	dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
163 }
164 
165 static __init void setup_topology(void)
166 {
167 	int max_mnest;
168 
169 	if (!test_facility(11))
170 		return;
171 	get_lowcore()->machine_flags |= MACHINE_FLAG_TOPOLOGY;
172 	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
173 		if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
174 			break;
175 	}
176 	topology_max_mnest = max_mnest;
177 }
178 
179 void __init __do_early_pgm_check(struct pt_regs *regs)
180 {
181 	struct lowcore *lc = get_lowcore();
182 	unsigned long ip;
183 
184 	regs->int_code = lc->pgm_int_code;
185 	regs->int_parm_long = lc->trans_exc_code;
186 	ip = __rewind_psw(regs->psw, regs->int_code >> 16);
187 
188 	/* Monitor Event? Might be a warning */
189 	if ((regs->int_code & PGM_INT_CODE_MASK) == 0x40) {
190 		if (report_bug(ip, regs) == BUG_TRAP_TYPE_WARN)
191 			return;
192 	}
193 	if (fixup_exception(regs))
194 		return;
195 	/*
196 	 * Unhandled exception - system cannot continue but try to get some
197 	 * helpful messages to the console. Use early_printk() to print
198 	 * some basic information in case it is too early for printk().
199 	 */
200 	register_early_console();
201 	early_printk("PANIC: early exception %04x PSW: %016lx %016lx\n",
202 		     regs->int_code & 0xffff, regs->psw.mask, regs->psw.addr);
203 	show_regs(regs);
204 	disabled_wait();
205 }
206 
207 static noinline __init void setup_lowcore_early(void)
208 {
209 	struct lowcore *lc = get_lowcore();
210 	psw_t psw;
211 
212 	psw.addr = (unsigned long)early_pgm_check_handler;
213 	psw.mask = PSW_KERNEL_BITS;
214 	lc->program_new_psw = psw;
215 	lc->preempt_count = INIT_PREEMPT_COUNT;
216 	lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
217 	lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
218 }
219 
220 static __init void detect_diag9c(void)
221 {
222 	unsigned int cpu_address;
223 	int rc;
224 
225 	cpu_address = stap();
226 	diag_stat_inc(DIAG_STAT_X09C);
227 	asm volatile(
228 		"	diag	%2,0,0x9c\n"
229 		"0:	la	%0,0\n"
230 		"1:\n"
231 		EX_TABLE(0b,1b)
232 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
233 	if (!rc)
234 		get_lowcore()->machine_flags |= MACHINE_FLAG_DIAG9C;
235 }
236 
237 static __init void detect_machine_facilities(void)
238 {
239 	if (test_facility(8)) {
240 		get_lowcore()->machine_flags |= MACHINE_FLAG_EDAT1;
241 		system_ctl_set_bit(0, CR0_EDAT_BIT);
242 	}
243 	if (test_facility(78))
244 		get_lowcore()->machine_flags |= MACHINE_FLAG_EDAT2;
245 	if (test_facility(3))
246 		get_lowcore()->machine_flags |= MACHINE_FLAG_IDTE;
247 	if (test_facility(50) && test_facility(73)) {
248 		get_lowcore()->machine_flags |= MACHINE_FLAG_TE;
249 		system_ctl_set_bit(0, CR0_TRANSACTIONAL_EXECUTION_BIT);
250 	}
251 	if (test_facility(51))
252 		get_lowcore()->machine_flags |= MACHINE_FLAG_TLB_LC;
253 	if (test_facility(129))
254 		system_ctl_set_bit(0, CR0_VECTOR_BIT);
255 	if (test_facility(130))
256 		get_lowcore()->machine_flags |= MACHINE_FLAG_NX;
257 	if (test_facility(133))
258 		get_lowcore()->machine_flags |= MACHINE_FLAG_GS;
259 	if (test_facility(139) && (tod_clock_base.tod >> 63)) {
260 		/* Enabled signed clock comparator comparisons */
261 		get_lowcore()->machine_flags |= MACHINE_FLAG_SCC;
262 		clock_comparator_max = -1ULL >> 1;
263 		system_ctl_set_bit(0, CR0_CLOCK_COMPARATOR_SIGN_BIT);
264 	}
265 	if (IS_ENABLED(CONFIG_PCI) && test_facility(153)) {
266 		get_lowcore()->machine_flags |= MACHINE_FLAG_PCI_MIO;
267 		/* the control bit is set during PCI initialization */
268 	}
269 	if (test_facility(194))
270 		get_lowcore()->machine_flags |= MACHINE_FLAG_RDP;
271 	if (test_facility(85))
272 		get_lowcore()->machine_flags |= MACHINE_FLAG_SEQ_INSN;
273 }
274 
275 static inline void save_vector_registers(void)
276 {
277 #ifdef CONFIG_CRASH_DUMP
278 	if (test_facility(129))
279 		save_vx_regs(boot_cpu_vector_save_area);
280 #endif
281 }
282 
283 static inline void setup_low_address_protection(void)
284 {
285 	system_ctl_set_bit(0, CR0_LOW_ADDRESS_PROTECTION_BIT);
286 }
287 
288 static inline void setup_access_registers(void)
289 {
290 	unsigned int acrs[NUM_ACRS] = { 0 };
291 
292 	restore_access_regs(acrs);
293 }
294 
295 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
296 static void __init setup_boot_command_line(void)
297 {
298 	/* copy arch command line */
299 	strscpy(boot_command_line, early_command_line, COMMAND_LINE_SIZE);
300 }
301 
302 static void __init sort_amode31_extable(void)
303 {
304 	sort_extable(__start_amode31_ex_table, __stop_amode31_ex_table);
305 }
306 
307 void __init startup_init(void)
308 {
309 	kasan_early_init();
310 	reset_tod_clock();
311 	time_early_init();
312 	init_kernel_storage_key();
313 	lockdep_off();
314 	sort_amode31_extable();
315 	setup_lowcore_early();
316 	detect_machine_type();
317 	setup_arch_string();
318 	setup_boot_command_line();
319 	detect_diag9c();
320 	detect_machine_facilities();
321 	save_vector_registers();
322 	setup_topology();
323 	sclp_early_detect();
324 	setup_low_address_protection();
325 	setup_access_registers();
326 	lockdep_on();
327 }
328