1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright IBM Corp. 2007, 2009
4 * Author(s): Hongjie Yang <hongjie@us.ibm.com>,
5 * Heiko Carstens <heiko.carstens@de.ibm.com>
6 */
7
8 #define KMSG_COMPONENT "setup"
9 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
10
11 #include <linux/compiler.h>
12 #include <linux/init.h>
13 #include <linux/errno.h>
14 #include <linux/string.h>
15 #include <linux/ctype.h>
16 #include <linux/lockdep.h>
17 #include <linux/extable.h>
18 #include <linux/pfn.h>
19 #include <linux/uaccess.h>
20 #include <linux/kernel.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
reset_tod_clock(void)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 */
init_kernel_storage_key(void)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
detect_machine_type(void)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. */
strim_all(char * str)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
setup_arch_string(void)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
setup_topology(void)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
early_pgm_check_handler(void)152 static void early_pgm_check_handler(void)
153 {
154 const struct exception_table_entry *fixup;
155 unsigned long cr0, cr0_new;
156 unsigned long addr;
157
158 addr = S390_lowcore.program_old_psw.addr;
159 fixup = s390_search_extables(addr);
160 if (!fixup)
161 disabled_wait();
162 /* Disable low address protection before storing into lowcore. */
163 __ctl_store(cr0, 0, 0);
164 cr0_new = cr0 & ~(1UL << 28);
165 __ctl_load(cr0_new, 0, 0);
166 S390_lowcore.program_old_psw.addr = extable_fixup(fixup);
167 __ctl_load(cr0, 0, 0);
168 }
169
setup_lowcore_early(void)170 static noinline __init void setup_lowcore_early(void)
171 {
172 psw_t psw;
173
174 psw.addr = (unsigned long)s390_base_pgm_handler;
175 psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
176 if (IS_ENABLED(CONFIG_KASAN))
177 psw.mask |= PSW_MASK_DAT;
178 S390_lowcore.program_new_psw = psw;
179 s390_base_pgm_handler_fn = early_pgm_check_handler;
180 S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
181 }
182
setup_facility_list(void)183 static noinline __init void setup_facility_list(void)
184 {
185 memcpy(alt_stfle_fac_list, stfle_fac_list, sizeof(alt_stfle_fac_list));
186 if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
187 __clear_facility(82, alt_stfle_fac_list);
188 }
189
detect_diag9c(void)190 static __init void detect_diag9c(void)
191 {
192 unsigned int cpu_address;
193 int rc;
194
195 cpu_address = stap();
196 diag_stat_inc(DIAG_STAT_X09C);
197 asm volatile(
198 " diag %2,0,0x9c\n"
199 "0: la %0,0\n"
200 "1:\n"
201 EX_TABLE(0b,1b)
202 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
203 if (!rc)
204 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
205 }
206
detect_machine_facilities(void)207 static __init void detect_machine_facilities(void)
208 {
209 if (test_facility(8)) {
210 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
211 __ctl_set_bit(0, 23);
212 }
213 if (test_facility(78))
214 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
215 if (test_facility(3))
216 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
217 if (test_facility(50) && test_facility(73)) {
218 S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
219 __ctl_set_bit(0, 55);
220 }
221 if (test_facility(51))
222 S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
223 if (test_facility(129)) {
224 S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
225 __ctl_set_bit(0, 17);
226 }
227 if (test_facility(130) && !noexec_disabled) {
228 S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
229 __ctl_set_bit(0, 20);
230 }
231 if (test_facility(133))
232 S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
233 if (test_facility(139) && (tod_clock_base.tod >> 63)) {
234 /* Enabled signed clock comparator comparisons */
235 S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
236 clock_comparator_max = -1ULL >> 1;
237 __ctl_set_bit(0, 53);
238 }
239 if (IS_ENABLED(CONFIG_PCI) && test_facility(153)) {
240 S390_lowcore.machine_flags |= MACHINE_FLAG_PCI_MIO;
241 /* the control bit is set during PCI initialization */
242 }
243 }
244
save_vector_registers(void)245 static inline void save_vector_registers(void)
246 {
247 #ifdef CONFIG_CRASH_DUMP
248 if (test_facility(129))
249 save_vx_regs(boot_cpu_vector_save_area);
250 #endif
251 }
252
setup_control_registers(void)253 static inline void setup_control_registers(void)
254 {
255 unsigned long reg;
256
257 __ctl_store(reg, 0, 0);
258 reg |= CR0_LOW_ADDRESS_PROTECTION;
259 reg |= CR0_EMERGENCY_SIGNAL_SUBMASK;
260 reg |= CR0_EXTERNAL_CALL_SUBMASK;
261 __ctl_load(reg, 0, 0);
262 }
263
setup_access_registers(void)264 static inline void setup_access_registers(void)
265 {
266 unsigned int acrs[NUM_ACRS] = { 0 };
267
268 restore_access_regs(acrs);
269 }
270
disable_vector_extension(char * str)271 static int __init disable_vector_extension(char *str)
272 {
273 S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
274 __ctl_clear_bit(0, 17);
275 return 0;
276 }
277 early_param("novx", disable_vector_extension);
278
279 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
setup_boot_command_line(void)280 static void __init setup_boot_command_line(void)
281 {
282 /* copy arch command line */
283 strlcpy(boot_command_line, early_command_line, ARCH_COMMAND_LINE_SIZE);
284 }
285
check_image_bootable(void)286 static void __init check_image_bootable(void)
287 {
288 if (is_full_image)
289 return;
290
291 sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n");
292 sclp_early_printk("This image does not contain all parts necessary for starting up. Use\n");
293 sclp_early_printk("bzImage or arch/s390/boot/compressed/vmlinux instead.\n");
294 disabled_wait();
295 }
296
startup_init(void)297 void __init startup_init(void)
298 {
299 reset_tod_clock();
300 check_image_bootable();
301 time_early_init();
302 init_kernel_storage_key();
303 lockdep_off();
304 setup_lowcore_early();
305 setup_facility_list();
306 detect_machine_type();
307 setup_arch_string();
308 setup_boot_command_line();
309 detect_diag9c();
310 detect_machine_facilities();
311 save_vector_registers();
312 setup_topology();
313 sclp_early_detect();
314 setup_control_registers();
315 setup_access_registers();
316 lockdep_on();
317 }
318