xref: /linux/arch/s390/kernel/early.c (revision 1a2ac6d7ecdcde74a4e16f31de64124160fc7237)
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 #define decompressor_handled_param(param)			\
40 static int __init ignore_decompressor_param_##param(char *s)	\
41 {								\
42 	return 0;						\
43 }								\
44 early_param(#param, ignore_decompressor_param_##param)
45 
46 decompressor_handled_param(mem);
47 decompressor_handled_param(vmalloc);
48 decompressor_handled_param(dfltcc);
49 decompressor_handled_param(noexec);
50 decompressor_handled_param(facilities);
51 decompressor_handled_param(nokaslr);
52 #if IS_ENABLED(CONFIG_KVM)
53 decompressor_handled_param(prot_virt);
54 #endif
55 
56 static void __init reset_tod_clock(void)
57 {
58 	union tod_clock clk;
59 
60 	if (store_tod_clock_ext_cc(&clk) == 0)
61 		return;
62 	/* TOD clock not running. Set the clock to Unix Epoch. */
63 	if (set_tod_clock(TOD_UNIX_EPOCH) || store_tod_clock_ext_cc(&clk))
64 		disabled_wait();
65 
66 	memset(&tod_clock_base, 0, sizeof(tod_clock_base));
67 	tod_clock_base.tod = TOD_UNIX_EPOCH;
68 	S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
69 }
70 
71 /*
72  * Initialize storage key for kernel pages
73  */
74 static noinline __init void init_kernel_storage_key(void)
75 {
76 #if PAGE_DEFAULT_KEY
77 	unsigned long end_pfn, init_pfn;
78 
79 	end_pfn = PFN_UP(__pa(_end));
80 
81 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
82 		page_set_storage_key(init_pfn << PAGE_SHIFT,
83 				     PAGE_DEFAULT_KEY, 0);
84 #endif
85 }
86 
87 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
88 
89 static noinline __init void detect_machine_type(void)
90 {
91 	struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
92 
93 	/* Check current-configuration-level */
94 	if (stsi(NULL, 0, 0, 0) <= 2) {
95 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
96 		return;
97 	}
98 	/* Get virtual-machine cpu information. */
99 	if (stsi(vmms, 3, 2, 2) || !vmms->count)
100 		return;
101 
102 	/* Detect known hypervisors */
103 	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
104 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
105 	else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
106 		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
107 }
108 
109 /* Remove leading, trailing and double whitespace. */
110 static inline void strim_all(char *str)
111 {
112 	char *s;
113 
114 	s = strim(str);
115 	if (s != str)
116 		memmove(str, s, strlen(s));
117 	while (*str) {
118 		if (!isspace(*str++))
119 			continue;
120 		if (isspace(*str)) {
121 			s = skip_spaces(str);
122 			memmove(str, s, strlen(s) + 1);
123 		}
124 	}
125 }
126 
127 static noinline __init void setup_arch_string(void)
128 {
129 	struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
130 	struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
131 	char mstr[80], hvstr[17];
132 
133 	if (stsi(mach, 1, 1, 1))
134 		return;
135 	EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
136 	EBCASC(mach->type, sizeof(mach->type));
137 	EBCASC(mach->model, sizeof(mach->model));
138 	EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
139 	sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
140 		mach->manufacturer, mach->type,
141 		mach->model, mach->model_capacity);
142 	strim_all(mstr);
143 	if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
144 		EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
145 		sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
146 		strim_all(hvstr);
147 	} else {
148 		sprintf(hvstr, "%s",
149 			MACHINE_IS_LPAR ? "LPAR" :
150 			MACHINE_IS_VM ? "z/VM" :
151 			MACHINE_IS_KVM ? "KVM" : "unknown");
152 	}
153 	dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
154 }
155 
156 static __init void setup_topology(void)
157 {
158 	int max_mnest;
159 
160 	if (!test_facility(11))
161 		return;
162 	S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
163 	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
164 		if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
165 			break;
166 	}
167 	topology_max_mnest = max_mnest;
168 }
169 
170 void __do_early_pgm_check(struct pt_regs *regs)
171 {
172 	if (!fixup_exception(regs))
173 		disabled_wait();
174 }
175 
176 static noinline __init void setup_lowcore_early(void)
177 {
178 	psw_t psw;
179 
180 	psw.addr = (unsigned long)early_pgm_check_handler;
181 	psw.mask = PSW_KERNEL_BITS;
182 	S390_lowcore.program_new_psw = psw;
183 	S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
184 }
185 
186 static noinline __init void setup_facility_list(void)
187 {
188 	memcpy(alt_stfle_fac_list, stfle_fac_list, sizeof(alt_stfle_fac_list));
189 	if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
190 		__clear_facility(82, alt_stfle_fac_list);
191 }
192 
193 static __init void detect_diag9c(void)
194 {
195 	unsigned int cpu_address;
196 	int rc;
197 
198 	cpu_address = stap();
199 	diag_stat_inc(DIAG_STAT_X09C);
200 	asm volatile(
201 		"	diag	%2,0,0x9c\n"
202 		"0:	la	%0,0\n"
203 		"1:\n"
204 		EX_TABLE(0b,1b)
205 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
206 	if (!rc)
207 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
208 }
209 
210 static __init void detect_machine_facilities(void)
211 {
212 	if (test_facility(8)) {
213 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
214 		__ctl_set_bit(0, 23);
215 	}
216 	if (test_facility(78))
217 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
218 	if (test_facility(3))
219 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
220 	if (test_facility(50) && test_facility(73)) {
221 		S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
222 		__ctl_set_bit(0, 55);
223 	}
224 	if (test_facility(51))
225 		S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
226 	if (test_facility(129)) {
227 		S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
228 		__ctl_set_bit(0, 17);
229 	}
230 	if (test_facility(130) && !noexec_disabled) {
231 		S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
232 		__ctl_set_bit(0, 20);
233 	}
234 	if (test_facility(133))
235 		S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
236 	if (test_facility(139) && (tod_clock_base.tod >> 63)) {
237 		/* Enabled signed clock comparator comparisons */
238 		S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
239 		clock_comparator_max = -1ULL >> 1;
240 		__ctl_set_bit(0, 53);
241 	}
242 	if (IS_ENABLED(CONFIG_PCI) && test_facility(153)) {
243 		S390_lowcore.machine_flags |= MACHINE_FLAG_PCI_MIO;
244 		/* the control bit is set during PCI initialization */
245 	}
246 	if (test_facility(194))
247 		S390_lowcore.machine_flags |= MACHINE_FLAG_RDP;
248 }
249 
250 static inline void save_vector_registers(void)
251 {
252 #ifdef CONFIG_CRASH_DUMP
253 	if (test_facility(129))
254 		save_vx_regs(boot_cpu_vector_save_area);
255 #endif
256 }
257 
258 static inline void setup_control_registers(void)
259 {
260 	unsigned long reg;
261 
262 	__ctl_store(reg, 0, 0);
263 	reg |= CR0_LOW_ADDRESS_PROTECTION;
264 	reg |= CR0_EMERGENCY_SIGNAL_SUBMASK;
265 	reg |= CR0_EXTERNAL_CALL_SUBMASK;
266 	__ctl_load(reg, 0, 0);
267 }
268 
269 static inline void setup_access_registers(void)
270 {
271 	unsigned int acrs[NUM_ACRS] = { 0 };
272 
273 	restore_access_regs(acrs);
274 }
275 
276 static int __init disable_vector_extension(char *str)
277 {
278 	S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
279 	__ctl_clear_bit(0, 17);
280 	return 0;
281 }
282 early_param("novx", disable_vector_extension);
283 
284 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
285 static void __init setup_boot_command_line(void)
286 {
287 	/* copy arch command line */
288 	strscpy(boot_command_line, early_command_line, COMMAND_LINE_SIZE);
289 }
290 
291 static void __init check_image_bootable(void)
292 {
293 	if (is_full_image)
294 		return;
295 
296 	sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n");
297 	sclp_early_printk("This image does not contain all parts necessary for starting up. Use\n");
298 	sclp_early_printk("bzImage or arch/s390/boot/compressed/vmlinux instead.\n");
299 	disabled_wait();
300 }
301 
302 static void __init sort_amode31_extable(void)
303 {
304 	sort_extable(__start_amode31_ex_table, __stop_amode31_ex_table);
305 }
306 
307 void __init startup_init(void)
308 {
309 	reset_tod_clock();
310 	check_image_bootable();
311 	time_early_init();
312 	init_kernel_storage_key();
313 	lockdep_off();
314 	sort_amode31_extable();
315 	setup_lowcore_early();
316 	setup_facility_list();
317 	detect_machine_type();
318 	setup_arch_string();
319 	setup_boot_command_line();
320 	detect_diag9c();
321 	detect_machine_facilities();
322 	save_vector_registers();
323 	setup_topology();
324 	sclp_early_detect();
325 	setup_control_registers();
326 	setup_access_registers();
327 	lockdep_on();
328 }
329