xref: /linux/arch/s390/kernel/early.c (revision d8e473182ab9e85708067be81d20424045d939fa)
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 int __bootdata(is_full_image);
38 
39 static void __init reset_tod_clock(void)
40 {
41 	union tod_clock clk;
42 
43 	if (store_tod_clock_ext_cc(&clk) == 0)
44 		return;
45 	/* TOD clock not running. Set the clock to Unix Epoch. */
46 	if (set_tod_clock(TOD_UNIX_EPOCH) || store_tod_clock_ext_cc(&clk))
47 		disabled_wait();
48 
49 	memset(&tod_clock_base, 0, sizeof(tod_clock_base));
50 	tod_clock_base.tod = TOD_UNIX_EPOCH;
51 	S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
52 }
53 
54 /*
55  * Initialize storage key for kernel pages
56  */
57 static noinline __init void init_kernel_storage_key(void)
58 {
59 #if PAGE_DEFAULT_KEY
60 	unsigned long end_pfn, init_pfn;
61 
62 	end_pfn = PFN_UP(__pa(_end));
63 
64 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
65 		page_set_storage_key(init_pfn << PAGE_SHIFT,
66 				     PAGE_DEFAULT_KEY, 0);
67 #endif
68 }
69 
70 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
71 
72 static noinline __init void detect_machine_type(void)
73 {
74 	struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
75 
76 	/* Check current-configuration-level */
77 	if (stsi(NULL, 0, 0, 0) <= 2) {
78 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
79 		return;
80 	}
81 	/* Get virtual-machine cpu information. */
82 	if (stsi(vmms, 3, 2, 2) || !vmms->count)
83 		return;
84 
85 	/* Detect known hypervisors */
86 	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
87 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
88 	else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
89 		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
90 }
91 
92 /* Remove leading, trailing and double whitespace. */
93 static inline void strim_all(char *str)
94 {
95 	char *s;
96 
97 	s = strim(str);
98 	if (s != str)
99 		memmove(str, s, strlen(s));
100 	while (*str) {
101 		if (!isspace(*str++))
102 			continue;
103 		if (isspace(*str)) {
104 			s = skip_spaces(str);
105 			memmove(str, s, strlen(s) + 1);
106 		}
107 	}
108 }
109 
110 static noinline __init void setup_arch_string(void)
111 {
112 	struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
113 	struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
114 	char mstr[80], hvstr[17];
115 
116 	if (stsi(mach, 1, 1, 1))
117 		return;
118 	EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
119 	EBCASC(mach->type, sizeof(mach->type));
120 	EBCASC(mach->model, sizeof(mach->model));
121 	EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
122 	sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
123 		mach->manufacturer, mach->type,
124 		mach->model, mach->model_capacity);
125 	strim_all(mstr);
126 	if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
127 		EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
128 		sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
129 		strim_all(hvstr);
130 	} else {
131 		sprintf(hvstr, "%s",
132 			MACHINE_IS_LPAR ? "LPAR" :
133 			MACHINE_IS_VM ? "z/VM" :
134 			MACHINE_IS_KVM ? "KVM" : "unknown");
135 	}
136 	dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
137 }
138 
139 static __init void setup_topology(void)
140 {
141 	int max_mnest;
142 
143 	if (!test_facility(11))
144 		return;
145 	S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
146 	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
147 		if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
148 			break;
149 	}
150 	topology_max_mnest = max_mnest;
151 }
152 
153 void __do_early_pgm_check(struct pt_regs *regs)
154 {
155 	if (!fixup_exception(regs))
156 		disabled_wait();
157 }
158 
159 static noinline __init void setup_lowcore_early(void)
160 {
161 	psw_t psw;
162 
163 	psw.addr = (unsigned long)early_pgm_check_handler;
164 	psw.mask = PSW_KERNEL_BITS;
165 	S390_lowcore.program_new_psw = psw;
166 	S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
167 }
168 
169 static noinline __init void setup_facility_list(void)
170 {
171 	memcpy(alt_stfle_fac_list, stfle_fac_list, sizeof(alt_stfle_fac_list));
172 	if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
173 		__clear_facility(82, alt_stfle_fac_list);
174 }
175 
176 static __init void detect_diag9c(void)
177 {
178 	unsigned int cpu_address;
179 	int rc;
180 
181 	cpu_address = stap();
182 	diag_stat_inc(DIAG_STAT_X09C);
183 	asm volatile(
184 		"	diag	%2,0,0x9c\n"
185 		"0:	la	%0,0\n"
186 		"1:\n"
187 		EX_TABLE(0b,1b)
188 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
189 	if (!rc)
190 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
191 }
192 
193 static __init void detect_machine_facilities(void)
194 {
195 	if (test_facility(8)) {
196 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
197 		__ctl_set_bit(0, 23);
198 	}
199 	if (test_facility(78))
200 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
201 	if (test_facility(3))
202 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
203 	if (test_facility(50) && test_facility(73)) {
204 		S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
205 		__ctl_set_bit(0, 55);
206 	}
207 	if (test_facility(51))
208 		S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
209 	if (test_facility(129)) {
210 		S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
211 		__ctl_set_bit(0, 17);
212 	}
213 	if (test_facility(130) && !noexec_disabled) {
214 		S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
215 		__ctl_set_bit(0, 20);
216 	}
217 	if (test_facility(133))
218 		S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
219 	if (test_facility(139) && (tod_clock_base.tod >> 63)) {
220 		/* Enabled signed clock comparator comparisons */
221 		S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
222 		clock_comparator_max = -1ULL >> 1;
223 		__ctl_set_bit(0, 53);
224 	}
225 	if (IS_ENABLED(CONFIG_PCI) && test_facility(153)) {
226 		S390_lowcore.machine_flags |= MACHINE_FLAG_PCI_MIO;
227 		/* the control bit is set during PCI initialization */
228 	}
229 	if (test_facility(194))
230 		S390_lowcore.machine_flags |= MACHINE_FLAG_RDP;
231 }
232 
233 static inline void save_vector_registers(void)
234 {
235 #ifdef CONFIG_CRASH_DUMP
236 	if (test_facility(129))
237 		save_vx_regs(boot_cpu_vector_save_area);
238 #endif
239 }
240 
241 static inline void setup_control_registers(void)
242 {
243 	unsigned long reg;
244 
245 	__ctl_store(reg, 0, 0);
246 	reg |= CR0_LOW_ADDRESS_PROTECTION;
247 	reg |= CR0_EMERGENCY_SIGNAL_SUBMASK;
248 	reg |= CR0_EXTERNAL_CALL_SUBMASK;
249 	__ctl_load(reg, 0, 0);
250 }
251 
252 static inline void setup_access_registers(void)
253 {
254 	unsigned int acrs[NUM_ACRS] = { 0 };
255 
256 	restore_access_regs(acrs);
257 }
258 
259 static int __init disable_vector_extension(char *str)
260 {
261 	S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
262 	__ctl_clear_bit(0, 17);
263 	return 0;
264 }
265 early_param("novx", disable_vector_extension);
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 check_image_bootable(void)
275 {
276 	if (is_full_image)
277 		return;
278 
279 	sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n");
280 	sclp_early_printk("This image does not contain all parts necessary for starting up. Use\n");
281 	sclp_early_printk("bzImage or arch/s390/boot/compressed/vmlinux instead.\n");
282 	disabled_wait();
283 }
284 
285 static void __init sort_amode31_extable(void)
286 {
287 	sort_extable(__start_amode31_ex_table, __stop_amode31_ex_table);
288 }
289 
290 void __init startup_init(void)
291 {
292 	reset_tod_clock();
293 	check_image_bootable();
294 	time_early_init();
295 	init_kernel_storage_key();
296 	lockdep_off();
297 	sort_amode31_extable();
298 	setup_lowcore_early();
299 	setup_facility_list();
300 	detect_machine_type();
301 	setup_arch_string();
302 	setup_boot_command_line();
303 	detect_diag9c();
304 	detect_machine_facilities();
305 	save_vector_registers();
306 	setup_topology();
307 	sclp_early_detect();
308 	setup_control_registers();
309 	setup_access_registers();
310 	lockdep_on();
311 }
312