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modules: catch concurrent module loads, treat them as idempotent
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1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *    Copyright IBM Corp. 2007, 2009
4  *    Author(s): Hongjie Yang <[email protected]>,
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(noexec);
48 decompressor_handled_param(facilities);
49 decompressor_handled_param(nokaslr);
50 #if IS_ENABLED(CONFIG_KVM)
51 decompressor_handled_param(prot_virt);
52 #endif
53
54 static void __init kasan_early_init(void)
55 {
56 #ifdef CONFIG_KASAN
57         init_task.kasan_depth = 0;
58         sclp_early_printk("KernelAddressSanitizer initialized\n");
59 #endif
60 }
61
62 static void __init reset_tod_clock(void)
63 {
64         union tod_clock clk;
65
66         if (store_tod_clock_ext_cc(&clk) == 0)
67                 return;
68         /* TOD clock not running. Set the clock to Unix Epoch. */
69         if (set_tod_clock(TOD_UNIX_EPOCH) || store_tod_clock_ext_cc(&clk))
70                 disabled_wait();
71
72         memset(&tod_clock_base, 0, sizeof(tod_clock_base));
73         tod_clock_base.tod = TOD_UNIX_EPOCH;
74         S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
75 }
76
77 /*
78  * Initialize storage key for kernel pages
79  */
80 static noinline __init void init_kernel_storage_key(void)
81 {
82 #if PAGE_DEFAULT_KEY
83         unsigned long end_pfn, init_pfn;
84
85         end_pfn = PFN_UP(__pa(_end));
86
87         for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
88                 page_set_storage_key(init_pfn << PAGE_SHIFT,
89                                      PAGE_DEFAULT_KEY, 0);
90 #endif
91 }
92
93 static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
94
95 static noinline __init void detect_machine_type(void)
96 {
97         struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
98
99         /* Check current-configuration-level */
100         if (stsi(NULL, 0, 0, 0) <= 2) {
101                 S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
102                 return;
103         }
104         /* Get virtual-machine cpu information. */
105         if (stsi(vmms, 3, 2, 2) || !vmms->count)
106                 return;
107
108         /* Detect known hypervisors */
109         if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
110                 S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
111         else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
112                 S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
113 }
114
115 /* Remove leading, trailing and double whitespace. */
116 static inline void strim_all(char *str)
117 {
118         char *s;
119
120         s = strim(str);
121         if (s != str)
122                 memmove(str, s, strlen(s));
123         while (*str) {
124                 if (!isspace(*str++))
125                         continue;
126                 if (isspace(*str)) {
127                         s = skip_spaces(str);
128                         memmove(str, s, strlen(s) + 1);
129                 }
130         }
131 }
132
133 static noinline __init void setup_arch_string(void)
134 {
135         struct sysinfo_1_1_1 *mach = (struct sysinfo_1_1_1 *)&sysinfo_page;
136         struct sysinfo_3_2_2 *vm = (struct sysinfo_3_2_2 *)&sysinfo_page;
137         char mstr[80], hvstr[17];
138
139         if (stsi(mach, 1, 1, 1))
140                 return;
141         EBCASC(mach->manufacturer, sizeof(mach->manufacturer));
142         EBCASC(mach->type, sizeof(mach->type));
143         EBCASC(mach->model, sizeof(mach->model));
144         EBCASC(mach->model_capacity, sizeof(mach->model_capacity));
145         sprintf(mstr, "%-16.16s %-4.4s %-16.16s %-16.16s",
146                 mach->manufacturer, mach->type,
147                 mach->model, mach->model_capacity);
148         strim_all(mstr);
149         if (stsi(vm, 3, 2, 2) == 0 && vm->count) {
150                 EBCASC(vm->vm[0].cpi, sizeof(vm->vm[0].cpi));
151                 sprintf(hvstr, "%-16.16s", vm->vm[0].cpi);
152                 strim_all(hvstr);
153         } else {
154                 sprintf(hvstr, "%s",
155                         MACHINE_IS_LPAR ? "LPAR" :
156                         MACHINE_IS_VM ? "z/VM" :
157                         MACHINE_IS_KVM ? "KVM" : "unknown");
158         }
159         dump_stack_set_arch_desc("%s (%s)", mstr, hvstr);
160 }
161
162 static __init void setup_topology(void)
163 {
164         int max_mnest;
165
166         if (!test_facility(11))
167                 return;
168         S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
169         for (max_mnest = 6; max_mnest > 1; max_mnest--) {
170                 if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
171                         break;
172         }
173         topology_max_mnest = max_mnest;
174 }
175
176 void __do_early_pgm_check(struct pt_regs *regs)
177 {
178         if (!fixup_exception(regs))
179                 disabled_wait();
180 }
181
182 static noinline __init void setup_lowcore_early(void)
183 {
184         psw_t psw;
185
186         psw.addr = (unsigned long)early_pgm_check_handler;
187         psw.mask = PSW_KERNEL_BITS;
188         S390_lowcore.program_new_psw = psw;
189         S390_lowcore.preempt_count = INIT_PREEMPT_COUNT;
190 }
191
192 static noinline __init void setup_facility_list(void)
193 {
194         memcpy(alt_stfle_fac_list, stfle_fac_list, sizeof(alt_stfle_fac_list));
195         if (!IS_ENABLED(CONFIG_KERNEL_NOBP))
196                 __clear_facility(82, alt_stfle_fac_list);
197 }
198
199 static __init void detect_diag9c(void)
200 {
201         unsigned int cpu_address;
202         int rc;
203
204         cpu_address = stap();
205         diag_stat_inc(DIAG_STAT_X09C);
206         asm volatile(
207                 "       diag    %2,0,0x9c\n"
208                 "0:     la      %0,0\n"
209                 "1:\n"
210                 EX_TABLE(0b,1b)
211                 : "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
212         if (!rc)
213                 S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
214 }
215
216 static __init void detect_machine_facilities(void)
217 {
218         if (test_facility(8)) {
219                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
220                 __ctl_set_bit(0, 23);
221         }
222         if (test_facility(78))
223                 S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
224         if (test_facility(3))
225                 S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
226         if (test_facility(50) && test_facility(73)) {
227                 S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
228                 __ctl_set_bit(0, 55);
229         }
230         if (test_facility(51))
231                 S390_lowcore.machine_flags |= MACHINE_FLAG_TLB_LC;
232         if (test_facility(129)) {
233                 S390_lowcore.machine_flags |= MACHINE_FLAG_VX;
234                 __ctl_set_bit(0, 17);
235         }
236         if (test_facility(130) && !noexec_disabled) {
237                 S390_lowcore.machine_flags |= MACHINE_FLAG_NX;
238                 __ctl_set_bit(0, 20);
239         }
240         if (test_facility(133))
241                 S390_lowcore.machine_flags |= MACHINE_FLAG_GS;
242         if (test_facility(139) && (tod_clock_base.tod >> 63)) {
243                 /* Enabled signed clock comparator comparisons */
244                 S390_lowcore.machine_flags |= MACHINE_FLAG_SCC;
245                 clock_comparator_max = -1ULL >> 1;
246                 __ctl_set_bit(0, 53);
247         }
248         if (IS_ENABLED(CONFIG_PCI) && test_facility(153)) {
249                 S390_lowcore.machine_flags |= MACHINE_FLAG_PCI_MIO;
250                 /* the control bit is set during PCI initialization */
251         }
252         if (test_facility(194))
253                 S390_lowcore.machine_flags |= MACHINE_FLAG_RDP;
254 }
255
256 static inline void save_vector_registers(void)
257 {
258 #ifdef CONFIG_CRASH_DUMP
259         if (test_facility(129))
260                 save_vx_regs(boot_cpu_vector_save_area);
261 #endif
262 }
263
264 static inline void setup_control_registers(void)
265 {
266         unsigned long reg;
267
268         __ctl_store(reg, 0, 0);
269         reg |= CR0_LOW_ADDRESS_PROTECTION;
270         reg |= CR0_EMERGENCY_SIGNAL_SUBMASK;
271         reg |= CR0_EXTERNAL_CALL_SUBMASK;
272         __ctl_load(reg, 0, 0);
273 }
274
275 static inline void setup_access_registers(void)
276 {
277         unsigned int acrs[NUM_ACRS] = { 0 };
278
279         restore_access_regs(acrs);
280 }
281
282 static int __init disable_vector_extension(char *str)
283 {
284         S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
285         __ctl_clear_bit(0, 17);
286         return 0;
287 }
288 early_param("novx", disable_vector_extension);
289
290 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
291 static void __init setup_boot_command_line(void)
292 {
293         /* copy arch command line */
294         strscpy(boot_command_line, early_command_line, COMMAND_LINE_SIZE);
295 }
296
297 static void __init sort_amode31_extable(void)
298 {
299         sort_extable(__start_amode31_ex_table, __stop_amode31_ex_table);
300 }
301
302 void __init startup_init(void)
303 {
304         kasan_early_init();
305         reset_tod_clock();
306         time_early_init();
307         init_kernel_storage_key();
308         lockdep_off();
309         sort_amode31_extable();
310         setup_lowcore_early();
311         setup_facility_list();
312         detect_machine_type();
313         setup_arch_string();
314         setup_boot_command_line();
315         detect_diag9c();
316         detect_machine_facilities();
317         save_vector_registers();
318         setup_topology();
319         sclp_early_detect();
320         setup_control_registers();
321         setup_access_registers();
322         lockdep_on();
323 }
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