xref: /linux/arch/s390/kernel/early.c (revision 955abe0a1b41de5ba61fe4cd614ebc123084d499)
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 decompressor_handled_param(relocate_lowcore);
52 #if IS_ENABLED(CONFIG_KVM)
53 decompressor_handled_param(prot_virt);
54 #endif
55 
56 static void __init kasan_early_init(void)
57 {
58 #ifdef CONFIG_KASAN
59 	init_task.kasan_depth = 0;
60 	sclp_early_printk("KernelAddressSanitizer initialized\n");
61 #endif
62 }
63 
64 static void __init reset_tod_clock(void)
65 {
66 	union tod_clock clk;
67 
68 	if (store_tod_clock_ext_cc(&clk) == 0)
69 		return;
70 	/* TOD clock not running. Set the clock to Unix Epoch. */
71 	if (set_tod_clock(TOD_UNIX_EPOCH) || store_tod_clock_ext_cc(&clk))
72 		disabled_wait();
73 
74 	memset(&tod_clock_base, 0, sizeof(tod_clock_base));
75 	tod_clock_base.tod = TOD_UNIX_EPOCH;
76 	get_lowcore()->last_update_clock = TOD_UNIX_EPOCH;
77 }
78 
79 /*
80  * Initialize storage key for kernel pages
81  */
82 static noinline __init void init_kernel_storage_key(void)
83 {
84 #if PAGE_DEFAULT_KEY
85 	unsigned long end_pfn, init_pfn;
86 
87 	end_pfn = PFN_UP(__pa(_end));
88 
89 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
90 		page_set_storage_key(init_pfn << PAGE_SHIFT,
91 				     PAGE_DEFAULT_KEY, 0);
92 #endif
93 }
94 
95 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
96 
97 static noinline __init void detect_machine_type(void)
98 {
99 	struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
100 
101 	/* Check current-configuration-level */
102 	if (stsi(NULL, 0, 0, 0) <= 2) {
103 		get_lowcore()->machine_flags |= MACHINE_FLAG_LPAR;
104 		return;
105 	}
106 	/* Get virtual-machine cpu information. */
107 	if (stsi(vmms, 3, 2, 2) || !vmms->count)
108 		return;
109 
110 	/* Detect known hypervisors */
111 	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
112 		get_lowcore()->machine_flags |= MACHINE_FLAG_KVM;
113 	else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
114 		get_lowcore()->machine_flags |= MACHINE_FLAG_VM;
115 }
116 
117 /* Remove leading, trailing and double whitespace. */
118 static inline void strim_all(char *str)
119 {
120 	char *s;
121 
122 	s = strim(str);
123 	if (s != str)
124 		memmove(str, s, strlen(s));
125 	while (*str) {
126 		if (!isspace(*str++))
127 			continue;
128 		if (isspace(*str)) {
129 			s = skip_spaces(str);
130 			memmove(str, s, strlen(s) + 1);
131 		}
132 	}
133 }
134 
135 static noinline __init void setup_arch_string(void)
136 {
137 	struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
138 	struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
139 	char mstr[80], hvstr[17];
140 
141 	if (stsi(mach, 1, 1, 1))
142 		return;
143 	EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
144 	EBCASC(mach->type, sizeof(mach->type));
145 	EBCASC(mach->model, sizeof(mach->model));
146 	EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
147 	sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
148 		mach->manufacturer, mach->type,
149 		mach->model, mach->model_capacity);
150 	strim_all(mstr);
151 	if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
152 		EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
153 		sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
154 		strim_all(hvstr);
155 	} else {
156 		sprintf(hvstr, "%s",
157 			MACHINE_IS_LPAR ? "LPAR" :
158 			MACHINE_IS_VM ? "z/VM" :
159 			MACHINE_IS_KVM ? "KVM" : "unknown");
160 	}
161 	dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
162 }
163 
164 static __init void setup_topology(void)
165 {
166 	int max_mnest;
167 
168 	if (!test_facility(11))
169 		return;
170 	get_lowcore()->machine_flags |= MACHINE_FLAG_TOPOLOGY;
171 	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
172 		if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
173 			break;
174 	}
175 	topology_max_mnest = max_mnest;
176 }
177 
178 void __do_early_pgm_check(struct pt_regs *regs)
179 {
180 	if (!fixup_exception(regs))
181 		disabled_wait();
182 }
183 
184 static noinline __init void setup_lowcore_early(void)
185 {
186 	psw_t psw;
187 
188 	psw.addr = (unsigned long)early_pgm_check_handler;
189 	psw.mask = PSW_KERNEL_BITS;
190 	get_lowcore()->program_new_psw = psw;
191 	get_lowcore()->preempt_count = INIT_PREEMPT_COUNT;
192 }
193 
194 static __init void detect_diag9c(void)
195 {
196 	unsigned int cpu_address;
197 	int rc;
198 
199 	cpu_address = stap();
200 	diag_stat_inc(DIAG_STAT_X09C);
201 	asm volatile(
202 		"	diag	%2,0,0x9c\n"
203 		"0:	la	%0,0\n"
204 		"1:\n"
205 		EX_TABLE(0b,1b)
206 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
207 	if (!rc)
208 		get_lowcore()->machine_flags |= MACHINE_FLAG_DIAG9C;
209 }
210 
211 static __init void detect_machine_facilities(void)
212 {
213 	if (test_facility(8)) {
214 		get_lowcore()->machine_flags |= MACHINE_FLAG_EDAT1;
215 		system_ctl_set_bit(0, CR0_EDAT_BIT);
216 	}
217 	if (test_facility(78))
218 		get_lowcore()->machine_flags |= MACHINE_FLAG_EDAT2;
219 	if (test_facility(3))
220 		get_lowcore()->machine_flags |= MACHINE_FLAG_IDTE;
221 	if (test_facility(50) && test_facility(73)) {
222 		get_lowcore()->machine_flags |= MACHINE_FLAG_TE;
223 		system_ctl_set_bit(0, CR0_TRANSACTIONAL_EXECUTION_BIT);
224 	}
225 	if (test_facility(51))
226 		get_lowcore()->machine_flags |= MACHINE_FLAG_TLB_LC;
227 	if (test_facility(129))
228 		system_ctl_set_bit(0, CR0_VECTOR_BIT);
229 	if (test_facility(130))
230 		get_lowcore()->machine_flags |= MACHINE_FLAG_NX;
231 	if (test_facility(133))
232 		get_lowcore()->machine_flags |= MACHINE_FLAG_GS;
233 	if (test_facility(139) && (tod_clock_base.tod >> 63)) {
234 		/* Enabled signed clock comparator comparisons */
235 		get_lowcore()->machine_flags |= MACHINE_FLAG_SCC;
236 		clock_comparator_max = -1ULL >> 1;
237 		system_ctl_set_bit(0, CR0_CLOCK_COMPARATOR_SIGN_BIT);
238 	}
239 	if (IS_ENABLED(CONFIG_PCI) && test_facility(153)) {
240 		get_lowcore()->machine_flags |= MACHINE_FLAG_PCI_MIO;
241 		/* the control bit is set during PCI initialization */
242 	}
243 	if (test_facility(194))
244 		get_lowcore()->machine_flags |= MACHINE_FLAG_RDP;
245 }
246 
247 static inline void save_vector_registers(void)
248 {
249 #ifdef CONFIG_CRASH_DUMP
250 	if (test_facility(129))
251 		save_vx_regs(boot_cpu_vector_save_area);
252 #endif
253 }
254 
255 static inline void setup_low_address_protection(void)
256 {
257 	system_ctl_set_bit(0, CR0_LOW_ADDRESS_PROTECTION_BIT);
258 }
259 
260 static inline void setup_access_registers(void)
261 {
262 	unsigned int acrs[NUM_ACRS] = { 0 };
263 
264 	restore_access_regs(acrs);
265 }
266 
267 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
268 static void __init setup_boot_command_line(void)
269 {
270 	/* copy arch command line */
271 	strscpy(boot_command_line, early_command_line, COMMAND_LINE_SIZE);
272 }
273 
274 static void __init sort_amode31_extable(void)
275 {
276 	sort_extable(__start_amode31_ex_table, __stop_amode31_ex_table);
277 }
278 
279 void __init startup_init(void)
280 {
281 	kasan_early_init();
282 	reset_tod_clock();
283 	time_early_init();
284 	init_kernel_storage_key();
285 	lockdep_off();
286 	sort_amode31_extable();
287 	setup_lowcore_early();
288 	detect_machine_type();
289 	setup_arch_string();
290 	setup_boot_command_line();
291 	detect_diag9c();
292 	detect_machine_facilities();
293 	save_vector_registers();
294 	setup_topology();
295 	sclp_early_detect();
296 	setup_low_address_protection();
297 	setup_access_registers();
298 	lockdep_on();
299 }
300