xref: /openbmc/linux/arch/s390/kernel/early.c (revision f4356947) 
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/diag.h>
23 #include <asm/ebcdic.h>
24 #include <asm/ipl.h>
25 #include <asm/lowcore.h>
26 #include <asm/processor.h>
27 #include <asm/sections.h>
28 #include <asm/setup.h>
29 #include <asm/sysinfo.h>
30 #include <asm/cpcmd.h>
31 #include <asm/sclp.h>
32 #include <asm/facility.h>
33 #include <asm/boot_data.h>
34 #include <asm/switch_to.h>
35 #include "entry.h"
36 
37 #define decompressor_handled_param(param)			\
38 static int __init ignore_decompressor_param_##param(char *s)	\
39 {								\
40 	return 0;						\
41 }								\
42 early_param(#param, ignore_decompressor_param_##param)
43 
44 decompressor_handled_param(mem);
45 decompressor_handled_param(vmalloc);
46 decompressor_handled_param(dfltcc);
47 decompressor_handled_param(noexec);
48 decompressor_handled_param(facilities);
49 decompressor_handled_param(nokaslr);
50 #if IS_ENABLED(CONFIG_KVM)
51 decompressor_handled_param(prot_virt);
52 #endif
53 
54 static void __init kasan_early_init(void)
55 {
56 #ifdef CONFIG_KASAN
57 	init_task.kasan_depth = 0;
58 	sclp_early_printk("KernelAddressSanitizer initialized\n");
59 #endif
60 }
61 
62 static void __init reset_tod_clock(void)
63 {
64 	union tod_clock clk;
65 
66 	if (store_tod_clock_ext_cc(&clk) == 0)
67 		return;
68 	/* TOD clock not running. Set the clock to Unix Epoch. */
69 	if (set_tod_clock(TOD_UNIX_EPOCH) || store_tod_clock_ext_cc(&clk))
70 		disabled_wait();
71 
72 	memset(&tod_clock_base, 0, sizeof(tod_clock_base));
73 	tod_clock_base.tod = TOD_UNIX_EPOCH;
74 	S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
75 }
76 
77 /*
78  * Initialize storage key for kernel pages
79  */
80 static noinline __init void init_kernel_storage_key(void)
81 {
82 #if PAGE_DEFAULT_KEY
83 	unsigned long end_pfn, init_pfn;
84 
85 	end_pfn = PFN_UP(__pa(_end));
86 
87 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
88 		page_set_storage_key(init_pfn << PAGE_SHIFT,
89 				     PAGE_DEFAULT_KEY, 0);
90 #endif
91 }
92 
93 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
94 
95 static noinline __init void detect_machine_type(void)
96 {
97 	struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
98 
99 	/* Check current-configuration-level */
100 	if (stsi(NULL, 0, 0, 0) <= 2) {
101 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
102 		return;
103 	}
104 	/* Get virtual-machine cpu information. */
105 	if (stsi(vmms, 3, 2, 2) || !vmms->count)
106 		return;
107 
108 	/* Detect known hypervisors */
109 	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
110 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
111 	else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
112 		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
113 }
114 
115 /* Remove leading, trailing and double whitespace. */
116 static inline void strim_all(char *str)
117 {
118 	char *s;
119 
120 	s = strim(str);
121 	if (s != str)
122 		memmove(str, s, strlen(s));
123 	while (*str) {
124 		if (!isspace(*str++))
125 			continue;
126 		if (isspace(*str)) {
127 			s = skip_spaces(str);
128 			memmove(str, s, strlen(s) + 1);
129 		}
130 	}
131 }
132 
133 static noinline __init void setup_arch_string(void)
134 {
135 	struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
136 	struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
137 	char mstr[80], hvstr[17];
138 
139 	if (stsi(mach, 1, 1, 1))
140 		return;
141 	EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
142 	EBCASC(mach->type, sizeof(mach->type));
143 	EBCASC(mach->model, sizeof(mach->model));
144 	EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
145 	sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
146 		mach->manufacturer, mach->type,
147 		mach->model, mach->model_capacity);
148 	strim_all(mstr);
149 	if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
150 		EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
151 		sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
152 		strim_all(hvstr);
153 	} else {
154 		sprintf(hvstr, "%s",
155 			MACHINE_IS_LPAR ? "LPAR" :
156 			MACHINE_IS_VM ? "z/VM" :
157 			MACHINE_IS_KVM ? "KVM" : "unknown");
158 	}
159 	dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
160 }
161 
162 static __init void setup_topology(void)
163 {
164 	int max_mnest;
165 
166 	if (!test_facility(11))
167 		return;
168 	S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
169 	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
170 		if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
171 			break;
172 	}
173 	topology_max_mnest = max_mnest;
174 }
175 
176 void __do_early_pgm_check(struct pt_regs *regs)
177 {
178 	if (!fixup_exception(regs))
179 		disabled_wait();
180 }
181 
182 static noinline __init void setup_lowcore_early(void)
183 {
184 	psw_t psw;
185 
186 	psw.addr = (unsigned long)early_pgm_check_handler;
187 	psw.mask = PSW_KERNEL_BITS;
188 	S390_lowcore.program_new_psw = psw;
189 	S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
190 }
191 
192 static noinline __init void setup_facility_list(void)
193 {
194 	memcpy(alt_stfle_fac_list, stfle_fac_list, sizeof(alt_stfle_fac_list));
195 	if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
196 		__clear_facility(82, alt_stfle_fac_list);
197 }
198 
199 static __init void detect_diag9c(void)
200 {
201 	unsigned int cpu_address;
202 	int rc;
203 
204 	cpu_address = stap();
205 	diag_stat_inc(DIAG_STAT_X09C);
206 	asm volatile(
207 		"	diag	%2,0,0x9c\n"
208 		"0:	la	%0,0\n"
209 		"1:\n"
210 		EX_TABLE(0b,1b)
211 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
212 	if (!rc)
213 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
214 }
215 
216 static __init void detect_machine_facilities(void)
217 {
218 	if (test_facility(8)) {
219 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
220 		__ctl_set_bit(0, 23);
221 	}
222 	if (test_facility(78))
223 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
224 	if (test_facility(3))
225 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
226 	if (test_facility(50) && test_facility(73)) {
227 		S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
228 		__ctl_set_bit(0, 55);
229 	}
230 	if (test_facility(51))
231 		S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
232 	if (test_facility(129)) {
233 		S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
234 		__ctl_set_bit(0, 17);
235 	}
236 	if (test_facility(130) && !noexec_disabled) {
237 		S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
238 		__ctl_set_bit(0, 20);
239 	}
240 	if (test_facility(133))
241 		S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
242 	if (test_facility(139) && (tod_clock_base.tod >> 63)) {
243 		/* Enabled signed clock comparator comparisons */
244 		S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
245 		clock_comparator_max = -1ULL >> 1;
246 		__ctl_set_bit(0, 53);
247 	}
248 	if (IS_ENABLED(CONFIG_PCI) && test_facility(153)) {
249 		S390_lowcore.machine_flags |= MACHINE_FLAG_PCI_MIO;
250 		/* the control bit is set during PCI initialization */
251 	}
252 	if (test_facility(194))
253 		S390_lowcore.machine_flags |= MACHINE_FLAG_RDP;
254 }
255 
256 static inline void save_vector_registers(void)
257 {
258 #ifdef CONFIG_CRASH_DUMP
259 	if (test_facility(129))
260 		save_vx_regs(boot_cpu_vector_save_area);
261 #endif
262 }
263 
264 static inline void setup_control_registers(void)
265 {
266 	unsigned long reg;
267 
268 	__ctl_store(reg, 0, 0);
269 	reg |= CR0_LOW_ADDRESS_PROTECTION;
270 	reg |= CR0_EMERGENCY_SIGNAL_SUBMASK;
271 	reg |= CR0_EXTERNAL_CALL_SUBMASK;
272 	__ctl_load(reg, 0, 0);
273 }
274 
275 static inline void setup_access_registers(void)
276 {
277 	unsigned int acrs[NUM_ACRS] = { 0 };
278 
279 	restore_access_regs(acrs);
280 }
281 
282 static int __init disable_vector_extension(char *str)
283 {
284 	S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
285 	__ctl_clear_bit(0, 17);
286 	return 0;
287 }
288 early_param("novx", disable_vector_extension);
289 
290 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
291 static void __init setup_boot_command_line(void)
292 {
293 	/* copy arch command line */
294 	strscpy(boot_command_line, early_command_line, COMMAND_LINE_SIZE);
295 }
296 
297 static void __init sort_amode31_extable(void)
298 {
299 	sort_extable(__start_amode31_ex_table, __stop_amode31_ex_table);
300 }
301 
302 void __init startup_init(void)
303 {
304 	kasan_early_init();
305 	reset_tod_clock();
306 	time_early_init();
307 	init_kernel_storage_key();
308 	lockdep_off();
309 	sort_amode31_extable();
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_machine_facilities();
317 	save_vector_registers();
318 	setup_topology();
319 	sclp_early_detect();
320 	setup_control_registers();
321 	setup_access_registers();
322 	lockdep_on();
323 }
324