xref: /linux/arch/s390/kernel/early.c (revision 8804d970fab45726b3c7cd7f240b31122aa94219)
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/cpufeature.h>
12 #include <linux/compiler.h>
13 #include <linux/init.h>
14 #include <linux/errno.h>
15 #include <linux/string.h>
16 #include <linux/ctype.h>
17 #include <linux/lockdep.h>
18 #include <linux/extable.h>
19 #include <linux/pfn.h>
20 #include <linux/uaccess.h>
21 #include <linux/kernel.h>
22 #include <asm/asm-extable.h>
23 #include <linux/memblock.h>
24 #include <linux/kasan.h>
25 #include <asm/access-regs.h>
26 #include <asm/asm-offsets.h>
27 #include <asm/machine.h>
28 #include <asm/diag.h>
29 #include <asm/ebcdic.h>
30 #include <asm/fpu.h>
31 #include <asm/ipl.h>
32 #include <asm/lowcore.h>
33 #include <asm/processor.h>
34 #include <asm/sections.h>
35 #include <asm/setup.h>
36 #include <asm/sysinfo.h>
37 #include <asm/cpcmd.h>
38 #include <asm/sclp.h>
39 #include <asm/facility.h>
40 #include <asm/boot_data.h>
41 #include "entry.h"
42 
43 #define __decompressor_handled_param(func, param)		\
44 static int __init ignore_decompressor_param_##func(char *s)	\
45 {								\
46 	return 0;						\
47 }								\
48 early_param(#param, ignore_decompressor_param_##func)
49 
50 #define decompressor_handled_param(param) __decompressor_handled_param(param, param)
51 
52 decompressor_handled_param(mem);
53 decompressor_handled_param(vmalloc);
54 decompressor_handled_param(dfltcc);
55 decompressor_handled_param(facilities);
56 decompressor_handled_param(nokaslr);
57 decompressor_handled_param(cmma);
58 decompressor_handled_param(relocate_lowcore);
59 decompressor_handled_param(bootdebug);
60 __decompressor_handled_param(debug_alternative, debug-alternative);
61 #if IS_ENABLED(CONFIG_KVM)
62 decompressor_handled_param(prot_virt);
63 #endif
64 
kasan_early_init(void)65 static void __init kasan_early_init(void)
66 {
67 #ifdef CONFIG_KASAN
68 	init_task.kasan_depth = 0;
69 	kasan_init_generic();
70 #endif
71 }
72 
73 /*
74  * Initialize storage key for kernel pages
75  */
init_kernel_storage_key(void)76 static noinline __init void init_kernel_storage_key(void)
77 {
78 #if PAGE_DEFAULT_KEY
79 	unsigned long end_pfn, init_pfn;
80 
81 	end_pfn = PFN_UP(__pa(_end));
82 
83 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
84 		page_set_storage_key(init_pfn << PAGE_SHIFT,
85 				     PAGE_DEFAULT_KEY, 0);
86 #endif
87 }
88 
89 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
90 
91 /* Remove leading, trailing and double whitespace. */
strim_all(char * str)92 static inline void strim_all(char *str)
93 {
94 	char *s;
95 
96 	s = strim(str);
97 	if (s != str)
98 		memmove(str, s, strlen(s));
99 	while (*str) {
100 		if (!isspace(*str++))
101 			continue;
102 		if (isspace(*str)) {
103 			s = skip_spaces(str);
104 			memmove(str, s, strlen(s) + 1);
105 		}
106 	}
107 }
108 
109 char arch_hw_string[128];
110 
setup_arch_string(void)111 static noinline __init void setup_arch_string(void)
112 {
113 	struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
114 	struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
115 	char mstr[80], hvstr[17];
116 
117 	if (stsi(mach, 1, 1, 1))
118 		return;
119 	EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
120 	EBCASC(mach->type, sizeof(mach->type));
121 	EBCASC(mach->model, sizeof(mach->model));
122 	EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
123 	sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
124 		mach->manufacturer, mach->type,
125 		mach->model, mach->model_capacity);
126 	strim_all(mstr);
127 	if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
128 		EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
129 		sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
130 		strim_all(hvstr);
131 	} else {
132 		sprintf(hvstr, "%s",
133 			machine_is_lpar() ? "LPAR" :
134 			machine_is_vm() ? "z/VM" :
135 			machine_is_kvm() ? "KVM" : "unknown");
136 	}
137 	sprintf(arch_hw_string, "HW: %s (%s)", mstr, hvstr);
138 	dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
139 }
140 
setup_topology(void)141 static __init void setup_topology(void)
142 {
143 	int max_mnest;
144 
145 	if (!cpu_has_topology())
146 		return;
147 	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
148 		if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
149 			break;
150 	}
151 	topology_max_mnest = max_mnest;
152 }
153 
__do_early_pgm_check(struct pt_regs * regs)154 void __init __do_early_pgm_check(struct pt_regs *regs)
155 {
156 	struct lowcore *lc = get_lowcore();
157 	unsigned long ip;
158 
159 	regs->int_code = lc->pgm_int_code;
160 	regs->int_parm_long = lc->trans_exc_code;
161 	regs->last_break = lc->pgm_last_break;
162 	ip = __rewind_psw(regs->psw, regs->int_code >> 16);
163 
164 	/* Monitor Event? Might be a warning */
165 	if ((regs->int_code & PGM_INT_CODE_MASK) == 0x40) {
166 		if (report_bug(ip, regs) == BUG_TRAP_TYPE_WARN)
167 			return;
168 	}
169 	if (fixup_exception(regs))
170 		return;
171 	/*
172 	 * Unhandled exception - system cannot continue but try to get some
173 	 * helpful messages to the console. Use early_printk() to print
174 	 * some basic information in case it is too early for printk().
175 	 */
176 	register_early_console();
177 	early_printk("PANIC: early exception %04x PSW: %016lx %016lx\n",
178 		     regs->int_code & 0xffff, regs->psw.mask, regs->psw.addr);
179 	show_regs(regs);
180 	disabled_wait();
181 }
182 
setup_lowcore_early(void)183 static noinline __init void setup_lowcore_early(void)
184 {
185 	struct lowcore *lc = get_lowcore();
186 	psw_t psw;
187 
188 	psw.addr = (unsigned long)early_pgm_check_handler;
189 	psw.mask = PSW_KERNEL_BITS;
190 	lc->program_new_psw = psw;
191 	lc->preempt_count = INIT_PREEMPT_COUNT;
192 	lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
193 	lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
194 }
195 
save_vector_registers(void)196 static inline void save_vector_registers(void)
197 {
198 #ifdef CONFIG_CRASH_DUMP
199 	if (cpu_has_vx())
200 		save_vx_regs(boot_cpu_vector_save_area);
201 #endif
202 }
203 
setup_low_address_protection(void)204 static inline void setup_low_address_protection(void)
205 {
206 	system_ctl_set_bit(0, CR0_LOW_ADDRESS_PROTECTION_BIT);
207 }
208 
setup_access_registers(void)209 static inline void setup_access_registers(void)
210 {
211 	unsigned int acrs[NUM_ACRS] = { 0 };
212 
213 	restore_access_regs(acrs);
214 }
215 
216 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
setup_boot_command_line(void)217 static void __init setup_boot_command_line(void)
218 {
219 	/* copy arch command line */
220 	strscpy(boot_command_line, early_command_line, COMMAND_LINE_SIZE);
221 }
222 
sort_amode31_extable(void)223 static void __init sort_amode31_extable(void)
224 {
225 	sort_extable(__start_amode31_ex_table, __stop_amode31_ex_table);
226 }
227 
startup_init(void)228 void __init startup_init(void)
229 {
230 	kasan_early_init();
231 	time_early_init();
232 	init_kernel_storage_key();
233 	lockdep_off();
234 	sort_amode31_extable();
235 	setup_lowcore_early();
236 	setup_arch_string();
237 	setup_boot_command_line();
238 	save_vector_registers();
239 	setup_topology();
240 	sclp_early_detect();
241 	setup_low_address_protection();
242 	setup_access_registers();
243 	lockdep_on();
244 }
245