xref: /openbmc/linux/arch/s390/kernel/early.c (revision 1504b6f9)
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 <asm/diag.h>
22 #include <asm/ebcdic.h>
23 #include <asm/ipl.h>
24 #include <asm/lowcore.h>
25 #include <asm/processor.h>
26 #include <asm/sections.h>
27 #include <asm/setup.h>
28 #include <asm/sysinfo.h>
29 #include <asm/cpcmd.h>
30 #include <asm/sclp.h>
31 #include <asm/facility.h>
32 #include <asm/boot_data.h>
33 #include <asm/switch_to.h>
34 #include "entry.h"
35 
36 int __bootdata(is_full_image);
37 
38 static void __init reset_tod_clock(void)
39 {
40 	union tod_clock clk;
41 
42 	if (store_tod_clock_ext_cc(&clk) == 0)
43 		return;
44 	/* TOD clock not running. Set the clock to Unix Epoch. */
45 	if (set_tod_clock(TOD_UNIX_EPOCH) || store_tod_clock_ext_cc(&clk))
46 		disabled_wait();
47 
48 	memset(&tod_clock_base, 0, sizeof(tod_clock_base));
49 	tod_clock_base.tod = TOD_UNIX_EPOCH;
50 	S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
51 }
52 
53 /*
54  * Initialize storage key for kernel pages
55  */
56 static noinline __init void init_kernel_storage_key(void)
57 {
58 #if PAGE_DEFAULT_KEY
59 	unsigned long end_pfn, init_pfn;
60 
61 	end_pfn = PFN_UP(__pa(_end));
62 
63 	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
64 		page_set_storage_key(init_pfn << PAGE_SHIFT,
65 				     PAGE_DEFAULT_KEY, 0);
66 #endif
67 }
68 
69 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
70 
71 static noinline __init void detect_machine_type(void)
72 {
73 	struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
74 
75 	/* Check current-configuration-level */
76 	if (stsi(NULL, 0, 0, 0) <= 2) {
77 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
78 		return;
79 	}
80 	/* Get virtual-machine cpu information. */
81 	if (stsi(vmms, 3, 2, 2) || !vmms->count)
82 		return;
83 
84 	/* Detect known hypervisors */
85 	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
86 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
87 	else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
88 		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
89 }
90 
91 /* Remove leading, trailing and double whitespace. */
92 static inline void strim_all(char *str)
93 {
94 	char *s;
95 
96 	s = strim(str);
97 	if (s != str)
98 		memmove(str, s, strlen(s));
99 	while (*str) {
100 		if (!isspace(*str++))
101 			continue;
102 		if (isspace(*str)) {
103 			s = skip_spaces(str);
104 			memmove(str, s, strlen(s) + 1);
105 		}
106 	}
107 }
108 
109 static noinline __init void setup_arch_string(void)
110 {
111 	struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
112 	struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
113 	char mstr[80], hvstr[17];
114 
115 	if (stsi(mach, 1, 1, 1))
116 		return;
117 	EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
118 	EBCASC(mach->type, sizeof(mach->type));
119 	EBCASC(mach->model, sizeof(mach->model));
120 	EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
121 	sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
122 		mach->manufacturer, mach->type,
123 		mach->model, mach->model_capacity);
124 	strim_all(mstr);
125 	if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
126 		EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
127 		sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
128 		strim_all(hvstr);
129 	} else {
130 		sprintf(hvstr, "%s",
131 			MACHINE_IS_LPAR ? "LPAR" :
132 			MACHINE_IS_VM ? "z/VM" :
133 			MACHINE_IS_KVM ? "KVM" : "unknown");
134 	}
135 	dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
136 }
137 
138 static __init void setup_topology(void)
139 {
140 	int max_mnest;
141 
142 	if (!test_facility(11))
143 		return;
144 	S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
145 	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
146 		if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
147 			break;
148 	}
149 	topology_max_mnest = max_mnest;
150 }
151 
152 void __do_early_pgm_check(struct pt_regs *regs)
153 {
154 	if (!fixup_exception(regs))
155 		disabled_wait();
156 }
157 
158 static noinline __init void setup_lowcore_early(void)
159 {
160 	psw_t psw;
161 
162 	psw.addr = (unsigned long)early_pgm_check_handler;
163 	psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
164 	if (IS_ENABLED(CONFIG_KASAN))
165 		psw.mask |= PSW_MASK_DAT;
166 	S390_lowcore.program_new_psw = psw;
167 	S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
168 }
169 
170 static noinline __init void setup_facility_list(void)
171 {
172 	memcpy(alt_stfle_fac_list, stfle_fac_list, sizeof(alt_stfle_fac_list));
173 	if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
174 		__clear_facility(82, alt_stfle_fac_list);
175 }
176 
177 static __init void detect_diag9c(void)
178 {
179 	unsigned int cpu_address;
180 	int rc;
181 
182 	cpu_address = stap();
183 	diag_stat_inc(DIAG_STAT_X09C);
184 	asm volatile(
185 		"	diag	%2,0,0x9c\n"
186 		"0:	la	%0,0\n"
187 		"1:\n"
188 		EX_TABLE(0b,1b)
189 		: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
190 	if (!rc)
191 		S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
192 }
193 
194 static __init void detect_machine_facilities(void)
195 {
196 	if (test_facility(8)) {
197 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
198 		__ctl_set_bit(0, 23);
199 	}
200 	if (test_facility(78))
201 		S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
202 	if (test_facility(3))
203 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
204 	if (test_facility(50) && test_facility(73)) {
205 		S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
206 		__ctl_set_bit(0, 55);
207 	}
208 	if (test_facility(51))
209 		S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
210 	if (test_facility(129)) {
211 		S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
212 		__ctl_set_bit(0, 17);
213 	}
214 	if (test_facility(130) && !noexec_disabled) {
215 		S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
216 		__ctl_set_bit(0, 20);
217 	}
218 	if (test_facility(133))
219 		S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
220 	if (test_facility(139) && (tod_clock_base.tod >> 63)) {
221 		/* Enabled signed clock comparator comparisons */
222 		S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
223 		clock_comparator_max = -1ULL >> 1;
224 		__ctl_set_bit(0, 53);
225 	}
226 	if (IS_ENABLED(CONFIG_PCI) && test_facility(153)) {
227 		S390_lowcore.machine_flags |= MACHINE_FLAG_PCI_MIO;
228 		/* the control bit is set during PCI initialization */
229 	}
230 }
231 
232 static inline void save_vector_registers(void)
233 {
234 #ifdef CONFIG_CRASH_DUMP
235 	if (test_facility(129))
236 		save_vx_regs(boot_cpu_vector_save_area);
237 #endif
238 }
239 
240 static inline void setup_control_registers(void)
241 {
242 	unsigned long reg;
243 
244 	__ctl_store(reg, 0, 0);
245 	reg |= CR0_LOW_ADDRESS_PROTECTION;
246 	reg |= CR0_EMERGENCY_SIGNAL_SUBMASK;
247 	reg |= CR0_EXTERNAL_CALL_SUBMASK;
248 	__ctl_load(reg, 0, 0);
249 }
250 
251 static inline void setup_access_registers(void)
252 {
253 	unsigned int acrs[NUM_ACRS] = { 0 };
254 
255 	restore_access_regs(acrs);
256 }
257 
258 static int __init disable_vector_extension(char *str)
259 {
260 	S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
261 	__ctl_clear_bit(0, 17);
262 	return 0;
263 }
264 early_param("novx", disable_vector_extension);
265 
266 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
267 static void __init setup_boot_command_line(void)
268 {
269 	/* copy arch command line */
270 	strscpy(boot_command_line, early_command_line, COMMAND_LINE_SIZE);
271 }
272 
273 static void __init check_image_bootable(void)
274 {
275 	if (is_full_image)
276 		return;
277 
278 	sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n");
279 	sclp_early_printk("This image does not contain all parts necessary for starting up. Use\n");
280 	sclp_early_printk("bzImage or arch/s390/boot/compressed/vmlinux instead.\n");
281 	disabled_wait();
282 }
283 
284 static void __init sort_amode31_extable(void)
285 {
286 	sort_extable(__start_amode31_ex_table, __stop_amode31_ex_table);
287 }
288 
289 void __init startup_init(void)
290 {
291 	sclp_early_adjust_va();
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