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1 /*
2  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3  * Licensed under the GPL
4  */
5 
6 #include <linux/delay.h>
7 #include <linux/init.h>
8 #include <linux/mm.h>
9 #include <linux/module.h>
10 #include <linux/seq_file.h>
11 #include <linux/string.h>
12 #include <linux/utsname.h>
13 #include <linux/sched.h>
14 #include <asm/pgtable.h>
15 #include <asm/processor.h>
16 #include <asm/setup.h>
17 #include <as-layout.h>
18 #include <arch.h>
19 #include <init.h>
20 #include <kern.h>
21 #include <kern_util.h>
22 #include <mem_user.h>
23 #include <os.h>
24 
25 #define DEFAULT_COMMAND_LINE "root=98:0"
26 
27 /* Changed in add_arg and setup_arch, which run before SMP is started */
28 static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 };
29 
add_arg(char * arg)30 static void __init add_arg(char *arg)
31 {
32 	if (strlen(command_line) + strlen(arg) + 1 > COMMAND_LINE_SIZE) {
33 		printf("add_arg: Too many command line arguments!\n");
34 		exit(1);
35 	}
36 	if (strlen(command_line) > 0)
37 		strcat(command_line, " ");
38 	strcat(command_line, arg);
39 }
40 
41 /*
42  * These fields are initialized at boot time and not changed.
43  * XXX This structure is used only in the non-SMP case.  Maybe this
44  * should be moved to smp.c.
45  */
46 struct cpuinfo_um boot_cpu_data = {
47 	.loops_per_jiffy	= 0,
48 	.ipi_pipe		= { -1, -1 }
49 };
50 
51 union thread_union cpu0_irqstack
52 	__attribute__((__section__(".data..init_irqstack"))) =
53 		{ INIT_THREAD_INFO(init_task) };
54 
thread_saved_pc(struct task_struct * task)55 unsigned long thread_saved_pc(struct task_struct *task)
56 {
57 	/* FIXME: Need to look up userspace_pid by cpu */
58 	return os_process_pc(userspace_pid[0]);
59 }
60 
61 /* Changed in setup_arch, which is called in early boot */
62 static char host_info[(__NEW_UTS_LEN + 1) * 5];
63 
show_cpuinfo(struct seq_file * m,void * v)64 static int show_cpuinfo(struct seq_file *m, void *v)
65 {
66 	int index = 0;
67 
68 #ifdef CONFIG_SMP
69 	index = (struct cpuinfo_um *) v - cpu_data;
70 	if (!cpu_online(index))
71 		return 0;
72 #endif
73 
74 	seq_printf(m, "processor\t: %d\n", index);
75 	seq_printf(m, "vendor_id\t: User Mode Linux\n");
76 	seq_printf(m, "model name\t: UML\n");
77 	seq_printf(m, "mode\t\t: skas\n");
78 	seq_printf(m, "host\t\t: %s\n", host_info);
79 	seq_printf(m, "bogomips\t: %lu.%02lu\n\n",
80 		   loops_per_jiffy/(500000/HZ),
81 		   (loops_per_jiffy/(5000/HZ)) % 100);
82 
83 	return 0;
84 }
85 
c_start(struct seq_file * m,loff_t * pos)86 static void *c_start(struct seq_file *m, loff_t *pos)
87 {
88 	return *pos < NR_CPUS ? cpu_data + *pos : NULL;
89 }
90 
c_next(struct seq_file * m,void * v,loff_t * pos)91 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
92 {
93 	++*pos;
94 	return c_start(m, pos);
95 }
96 
c_stop(struct seq_file * m,void * v)97 static void c_stop(struct seq_file *m, void *v)
98 {
99 }
100 
101 const struct seq_operations cpuinfo_op = {
102 	.start	= c_start,
103 	.next	= c_next,
104 	.stop	= c_stop,
105 	.show	= show_cpuinfo,
106 };
107 
108 /* Set in linux_main */
109 unsigned long uml_physmem;
110 EXPORT_SYMBOL(uml_physmem);
111 
112 unsigned long uml_reserved; /* Also modified in mem_init */
113 unsigned long start_vm;
114 unsigned long end_vm;
115 
116 /* Set in uml_ncpus_setup */
117 int ncpus = 1;
118 
119 /* Set in early boot */
120 static int have_root __initdata = 0;
121 
122 /* Set in uml_mem_setup and modified in linux_main */
123 long long physmem_size = 32 * 1024 * 1024;
124 
125 static const char *usage_string =
126 "User Mode Linux v%s\n"
127 "	available at http://user-mode-linux.sourceforge.net/\n\n";
128 
uml_version_setup(char * line,int * add)129 static int __init uml_version_setup(char *line, int *add)
130 {
131 	printf("%s\n", init_utsname()->release);
132 	exit(0);
133 
134 	return 0;
135 }
136 
137 __uml_setup("--version", uml_version_setup,
138 "--version\n"
139 "    Prints the version number of the kernel.\n\n"
140 );
141 
uml_root_setup(char * line,int * add)142 static int __init uml_root_setup(char *line, int *add)
143 {
144 	have_root = 1;
145 	return 0;
146 }
147 
148 __uml_setup("root=", uml_root_setup,
149 "root=<file containing the root fs>\n"
150 "    This is actually used by the generic kernel in exactly the same\n"
151 "    way as in any other kernel. If you configure a number of block\n"
152 "    devices and want to boot off something other than ubd0, you \n"
153 "    would use something like:\n"
154 "        root=/dev/ubd5\n\n"
155 );
156 
no_skas_debug_setup(char * line,int * add)157 static int __init no_skas_debug_setup(char *line, int *add)
158 {
159 	printf("'debug' is not necessary to gdb UML in skas mode - run \n");
160 	printf("'gdb linux'\n");
161 
162 	return 0;
163 }
164 
165 __uml_setup("debug", no_skas_debug_setup,
166 "debug\n"
167 "    this flag is not needed to run gdb on UML in skas mode\n\n"
168 );
169 
170 #ifdef CONFIG_SMP
uml_ncpus_setup(char * line,int * add)171 static int __init uml_ncpus_setup(char *line, int *add)
172 {
173 	if (!sscanf(line, "%d", &ncpus)) {
174 		printf("Couldn't parse [%s]\n", line);
175 		return -1;
176 	}
177 
178 	return 0;
179 }
180 
181 __uml_setup("ncpus=", uml_ncpus_setup,
182 "ncpus=<# of desired CPUs>\n"
183 "    This tells an SMP kernel how many virtual processors to start.\n\n"
184 );
185 #endif
186 
Usage(char * line,int * add)187 static int __init Usage(char *line, int *add)
188 {
189 	const char **p;
190 
191 	printf(usage_string, init_utsname()->release);
192 	p = &__uml_help_start;
193 	while (p < &__uml_help_end) {
194 		printf("%s", *p);
195 		p++;
196 	}
197 	exit(0);
198 	return 0;
199 }
200 
201 __uml_setup("--help", Usage,
202 "--help\n"
203 "    Prints this message.\n\n"
204 );
205 
uml_checksetup(char * line,int * add)206 static void __init uml_checksetup(char *line, int *add)
207 {
208 	struct uml_param *p;
209 
210 	p = &__uml_setup_start;
211 	while (p < &__uml_setup_end) {
212 		size_t n;
213 
214 		n = strlen(p->str);
215 		if (!strncmp(line, p->str, n) && p->setup_func(line + n, add))
216 			return;
217 		p++;
218 	}
219 }
220 
uml_postsetup(void)221 static void __init uml_postsetup(void)
222 {
223 	initcall_t *p;
224 
225 	p = &__uml_postsetup_start;
226 	while (p < &__uml_postsetup_end) {
227 		(*p)();
228 		p++;
229 	}
230 	return;
231 }
232 
panic_exit(struct notifier_block * self,unsigned long unused1,void * unused2)233 static int panic_exit(struct notifier_block *self, unsigned long unused1,
234 		      void *unused2)
235 {
236 	bust_spinlocks(1);
237 	show_regs(&(current->thread.regs));
238 	bust_spinlocks(0);
239 	uml_exitcode = 1;
240 	os_dump_core();
241 	return 0;
242 }
243 
244 static struct notifier_block panic_exit_notifier = {
245 	.notifier_call 		= panic_exit,
246 	.next 			= NULL,
247 	.priority 		= 0
248 };
249 
250 /* Set during early boot */
251 unsigned long task_size;
252 EXPORT_SYMBOL(task_size);
253 
254 unsigned long host_task_size;
255 
256 unsigned long brk_start;
257 unsigned long end_iomem;
258 EXPORT_SYMBOL(end_iomem);
259 
260 #define MIN_VMALLOC (32 * 1024 * 1024)
261 
262 extern char __binary_start;
263 
linux_main(int argc,char ** argv)264 int __init linux_main(int argc, char **argv)
265 {
266 	unsigned long avail, diff;
267 	unsigned long virtmem_size, max_physmem;
268 	unsigned long stack;
269 	unsigned int i;
270 	int add;
271 	char * mode;
272 
273 	for (i = 1; i < argc; i++) {
274 		if ((i == 1) && (argv[i][0] == ' '))
275 			continue;
276 		add = 1;
277 		uml_checksetup(argv[i], &add);
278 		if (add)
279 			add_arg(argv[i]);
280 	}
281 	if (have_root == 0)
282 		add_arg(DEFAULT_COMMAND_LINE);
283 
284 	host_task_size = os_get_top_address();
285 	/*
286 	 * TASK_SIZE needs to be PGDIR_SIZE aligned or else exit_mmap craps
287 	 * out
288 	 */
289 	task_size = host_task_size & PGDIR_MASK;
290 
291 	/* OS sanity checks that need to happen before the kernel runs */
292 	os_early_checks();
293 
294 	can_do_skas();
295 
296 	if (proc_mm && ptrace_faultinfo)
297 		mode = "SKAS3";
298 	else
299 		mode = "SKAS0";
300 
301 	printf("UML running in %s mode\n", mode);
302 
303 	brk_start = (unsigned long) sbrk(0);
304 
305 	/*
306 	 * Increase physical memory size for exec-shield users
307 	 * so they actually get what they asked for. This should
308 	 * add zero for non-exec shield users
309 	 */
310 
311 	diff = UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
312 	if (diff > 1024 * 1024) {
313 		printf("Adding %ld bytes to physical memory to account for "
314 		       "exec-shield gap\n", diff);
315 		physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
316 	}
317 
318 	uml_physmem = (unsigned long) &__binary_start & PAGE_MASK;
319 
320 	/* Reserve up to 4M after the current brk */
321 	uml_reserved = ROUND_4M(brk_start) + (1 << 22);
322 
323 	setup_machinename(init_utsname()->machine);
324 
325 	highmem = 0;
326 	iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
327 	max_physmem = TASK_SIZE - uml_physmem - iomem_size - MIN_VMALLOC;
328 
329 	/*
330 	 * Zones have to begin on a 1 << MAX_ORDER page boundary,
331 	 * so this makes sure that's true for highmem
332 	 */
333 	max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER)) - 1);
334 	if (physmem_size + iomem_size > max_physmem) {
335 		highmem = physmem_size + iomem_size - max_physmem;
336 		physmem_size -= highmem;
337 #ifndef CONFIG_HIGHMEM
338 		highmem = 0;
339 		printf("CONFIG_HIGHMEM not enabled - physical memory shrunk "
340 		       "to %Lu bytes\n", physmem_size);
341 #endif
342 	}
343 
344 	high_physmem = uml_physmem + physmem_size;
345 	end_iomem = high_physmem + iomem_size;
346 	high_memory = (void *) end_iomem;
347 
348 	start_vm = VMALLOC_START;
349 
350 	setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
351 	if (init_maps(physmem_size, iomem_size, highmem)) {
352 		printf("Failed to allocate mem_map for %Lu bytes of physical "
353 		       "memory and %Lu bytes of highmem\n", physmem_size,
354 		       highmem);
355 		exit(1);
356 	}
357 
358 	virtmem_size = physmem_size;
359 	stack = (unsigned long) argv;
360 	stack &= ~(1024 * 1024 - 1);
361 	avail = stack - start_vm;
362 	if (physmem_size > avail)
363 		virtmem_size = avail;
364 	end_vm = start_vm + virtmem_size;
365 
366 	if (virtmem_size < physmem_size)
367 		printf("Kernel virtual memory size shrunk to %lu bytes\n",
368 		       virtmem_size);
369 
370 	atomic_notifier_chain_register(&panic_notifier_list,
371 				       &panic_exit_notifier);
372 
373 	uml_postsetup();
374 
375 	stack_protections((unsigned long) &init_thread_info);
376 	os_flush_stdout();
377 
378 	return start_uml();
379 }
380 
setup_arch(char ** cmdline_p)381 void __init setup_arch(char **cmdline_p)
382 {
383 	paging_init();
384 	strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
385 	*cmdline_p = command_line;
386 	setup_hostinfo(host_info, sizeof host_info);
387 }
388 
check_bugs(void)389 void __init check_bugs(void)
390 {
391 	arch_check_bugs();
392 	os_check_bugs();
393 }
394 
apply_alternatives(struct alt_instr * start,struct alt_instr * end)395 void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
396 {
397 }
398 
399 #ifdef CONFIG_SMP
alternatives_smp_module_add(struct module * mod,char * name,void * locks,void * locks_end,void * text,void * text_end)400 void alternatives_smp_module_add(struct module *mod, char *name,
401 				 void *locks, void *locks_end,
402 				 void *text,  void *text_end)
403 {
404 }
405 
alternatives_smp_module_del(struct module * mod)406 void alternatives_smp_module_del(struct module *mod)
407 {
408 }
409 #endif
410