xref: /openbmc/linux/arch/s390/kernel/early.c (revision a325f174) 
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(facilities);
48 decompressor_handled_param(nokaslr);
49 #if IS_ENABLED(CONFIG_KVM)
50 decompressor_handled_param(prot_virt);
51 #endif
52 
53 static void __init kasan_early_init(void)
54 {
55 #ifdef CONFIG_KASAN
56 	init_task.kasan_depth = 0;
57 	sclp_early_printk("KernelAddressSanitizer initialized\n");
58 #endif
59 }
60 
61 static void __init reset_tod_clock(void)
62 {
63 	union tod_clock clk;
64 
65 	if (store_tod_clock_ext_cc(&clk) == 0)
66 		return;
67 	/* TOD clock not running. Set the clock to Unix Epoch. */
68 	if (set_tod_clock(TOD_UNIX_EPOCH) || store_tod_clock_ext_cc(&clk))
69 		disabled_wait();
70 
71 	memset(&tod_clock_base, 0, sizeof(tod_clock_base));
72 	tod_clock_base.tod = TOD_UNIX_EPOCH;
73 	S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
74 }
75 
76 /*
77  * Initialize storage key for kernel pages
78  */
79 static noinline __init void init_kernel_storage_key(void)
80 {
81 #if PAGE_DEFAULT_KEY
82 	unsigned long end_pfn, init_pfn;
83 
84 	end_pfn = PFN_UP(__pa(_end));
85 
86 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
87 		page_set_storage_key(init_pfn << PAGE_SHIFT,
88 				     PAGE_DEFAULT_KEY, 0);
89 #endif
90 }
91 
92 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
93 
94 static noinline __init void detect_machine_type(void)
95 {
96 	struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
97 
98 	/* Check current-configuration-level */
99 	if (stsi(NULL, 0, 0, 0) <= 2) {
100 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
101 		return;
102 	}
103 	/* Get virtual-machine cpu information. */
104 	if (stsi(vmms, 3, 2, 2) || !vmms->count)
105 		return;
106 
107 	/* Detect known hypervisors */
108 	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
109 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
110 	else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
111 		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
112 }
113 
114 /* Remove leading, trailing and double whitespace. */
115 static inline void strim_all(char *str)
116 {
117 	char *s;
118 
119 	s = strim(str);
120 	if (s != str)
121 		memmove(str, s, strlen(s));
122 	while (*str) {
123 		if (!isspace(*str++))
124 			continue;
125 		if (isspace(*str)) {
126 			s = skip_spaces(str);
127 			memmove(str, s, strlen(s) + 1);
128 		}
129 	}
130 }
131 
132 static noinline __init void setup_arch_string(void)
133 {
134 	struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
135 	struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
136 	char mstr[80], hvstr[17];
137 
138 	if (stsi(mach, 1, 1, 1))
139 		return;
140 	EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
141 	EBCASC(mach->type, sizeof(mach->type));
142 	EBCASC(mach->model, sizeof(mach->model));
143 	EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
144 	sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
145 		mach->manufacturer, mach->type,
146 		mach->model, mach->model_capacity);
147 	strim_all(mstr);
148 	if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
149 		EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
150 		sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
151 		strim_all(hvstr);
152 	} else {
153 		sprintf(hvstr, "%s",
154 			MACHINE_IS_LPAR ? "LPAR" :
155 			MACHINE_IS_VM ? "z/VM" :
156 			MACHINE_IS_KVM ? "KVM" : "unknown");
157 	}
158 	dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
159 }
160 
161 static __init void setup_topology(void)
162 {
163 	int max_mnest;
164 
165 	if (!test_facility(11))
166 		return;
167 	S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
168 	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
169 		if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
170 			break;
171 	}
172 	topology_max_mnest = max_mnest;
173 }
174 
175 void __do_early_pgm_check(struct pt_regs *regs)
176 {
177 	if (!fixup_exception(regs))
178 		disabled_wait();
179 }
180 
181 static noinline __init void setup_lowcore_early(void)
182 {
183 	psw_t psw;
184 
185 	psw.addr = (unsigned long)early_pgm_check_handler;
186 	psw.mask = PSW_KERNEL_BITS;
187 	S390_lowcore.program_new_psw = psw;
188 	S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
189 }
190 
191 static noinline __init void setup_facility_list(void)
192 {
193 	memcpy(alt_stfle_fac_list, stfle_fac_list, sizeof(alt_stfle_fac_list));
194 	if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
195 		__clear_facility(82, alt_stfle_fac_list);
196 }
197 
198 static __init void detect_diag9c(void)
199 {
200 	unsigned int cpu_address;
201 	int rc;
202 
203 	cpu_address = stap();
204 	diag_stat_inc(DIAG_STAT_X09C);
205 	asm volatile(
206 		"	diag	%2,0,0x9c\n"
207 		"0:	la	%0,0\n"
208 		"1:\n"
209 		EX_TABLE(0b,1b)
210 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
211 	if (!rc)
212 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
213 }
214 
215 static __init void detect_machine_facilities(void)
216 {
217 	if (test_facility(8)) {
218 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
219 		__ctl_set_bit(0, 23);
220 	}
221 	if (test_facility(78))
222 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
223 	if (test_facility(3))
224 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
225 	if (test_facility(50) && test_facility(73)) {
226 		S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
227 		__ctl_set_bit(0, 55);
228 	}
229 	if (test_facility(51))
230 		S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
231 	if (test_facility(129)) {
232 		S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
233 		__ctl_set_bit(0, 17);
234 	}
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 		__ctl_set_bit(0, 53);
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_control_registers(void)
262 {
263 	unsigned long reg;
264 
265 	__ctl_store(reg, 0, 0);
266 	reg |= CR0_LOW_ADDRESS_PROTECTION;
267 	reg |= CR0_EMERGENCY_SIGNAL_SUBMASK;
268 	reg |= CR0_EXTERNAL_CALL_SUBMASK;
269 	__ctl_load(reg, 0, 0);
270 }
271 
272 static inline void setup_access_registers(void)
273 {
274 	unsigned int acrs[NUM_ACRS] = { 0 };
275 
276 	restore_access_regs(acrs);
277 }
278 
279 static int __init disable_vector_extension(char *str)
280 {
281 	S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
282 	__ctl_clear_bit(0, 17);
283 	return 0;
284 }
285 early_param("novx", disable_vector_extension);
286 
287 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
288 static void __init setup_boot_command_line(void)
289 {
290 	/* copy arch command line */
291 	strscpy(boot_command_line, early_command_line, COMMAND_LINE_SIZE);
292 }
293 
294 static void __init sort_amode31_extable(void)
295 {
296 	sort_extable(__start_amode31_ex_table, __stop_amode31_ex_table);
297 }
298 
299 void __init startup_init(void)
300 {
301 	kasan_early_init();
302 	reset_tod_clock();
303 	time_early_init();
304 	init_kernel_storage_key();
305 	lockdep_off();
306 	sort_amode31_extable();
307 	setup_lowcore_early();
308 	setup_facility_list();
309 	detect_machine_type();
310 	setup_arch_string();
311 	setup_boot_command_line();
312 	detect_diag9c();
313 	detect_machine_facilities();
314 	save_vector_registers();
315 	setup_topology();
316 	sclp_early_detect();
317 	setup_control_registers();
318 	setup_access_registers();
319 	lockdep_on();
320 }
321