Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
setup.c
Go to the documentation of this file.
1 /*
2  * Based on arch/arm/kernel/setup.c
3  *
4  * Copyright (C) 1995-2001 Russell King
5  * Copyright (C) 2012 ARM Ltd.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program. If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include <linux/export.h>
21 #include <linux/kernel.h>
22 #include <linux/stddef.h>
23 #include <linux/ioport.h>
24 #include <linux/delay.h>
25 #include <linux/utsname.h>
26 #include <linux/initrd.h>
27 #include <linux/console.h>
28 #include <linux/bootmem.h>
29 #include <linux/seq_file.h>
30 #include <linux/screen_info.h>
31 #include <linux/init.h>
32 #include <linux/kexec.h>
33 #include <linux/crash_dump.h>
34 #include <linux/root_dev.h>
35 #include <linux/cpu.h>
36 #include <linux/interrupt.h>
37 #include <linux/smp.h>
38 #include <linux/fs.h>
39 #include <linux/proc_fs.h>
40 #include <linux/memblock.h>
41 #include <linux/of_fdt.h>
42 
43 #include <asm/cputype.h>
44 #include <asm/elf.h>
45 #include <asm/cputable.h>
46 #include <asm/sections.h>
47 #include <asm/setup.h>
48 #include <asm/cacheflush.h>
49 #include <asm/tlbflush.h>
50 #include <asm/traps.h>
51 #include <asm/memblock.h>
52 
53 unsigned int processor_id;
55 
56 unsigned int elf_hwcap __read_mostly;
58 
59 static const char *cpu_name;
60 static const char *machine_name;
61 phys_addr_t __fdt_pointer __initdata;
62 
63 /*
64  * Standard memory resources
65  */
66 static struct resource mem_res[] = {
67  {
68  .name = "Kernel code",
69  .start = 0,
70  .end = 0,
71  .flags = IORESOURCE_MEM
72  },
73  {
74  .name = "Kernel data",
75  .start = 0,
76  .end = 0,
77  .flags = IORESOURCE_MEM
78  }
79 };
80 
81 #define kernel_code mem_res[0]
82 #define kernel_data mem_res[1]
83 
84 void __init early_print(const char *str, ...)
85 {
86  char buf[256];
87  va_list ap;
88 
89  va_start(ap, str);
90  vsnprintf(buf, sizeof(buf), str, ap);
91  va_end(ap);
92 
93  printk("%s", buf);
94 }
95 
96 static void __init setup_processor(void)
97 {
98  struct cpu_info *cpu_info;
99 
100  /*
101  * locate processor in the list of supported processor
102  * types. The linker builds this table for us from the
103  * entries in arch/arm/mm/proc.S
104  */
105  cpu_info = lookup_processor_type(read_cpuid_id());
106  if (!cpu_info) {
107  printk("CPU configuration botched (ID %08x), unable to continue.\n",
108  read_cpuid_id());
109  while (1);
110  }
111 
112  cpu_name = cpu_info->cpu_name;
113 
114  printk("CPU: %s [%08x] revision %d\n",
115  cpu_name, read_cpuid_id(), read_cpuid_id() & 15);
116 
117  sprintf(init_utsname()->machine, "aarch64");
118  elf_hwcap = 0;
119 }
120 
121 static void __init setup_machine_fdt(phys_addr_t dt_phys)
122 {
123  struct boot_param_header *devtree;
124  unsigned long dt_root;
125 
126  /* Check we have a non-NULL DT pointer */
127  if (!dt_phys) {
128  early_print("\n"
129  "Error: NULL or invalid device tree blob\n"
130  "The dtb must be 8-byte aligned and passed in the first 512MB of memory\n"
131  "\nPlease check your bootloader.\n");
132 
133  while (true)
134  cpu_relax();
135 
136  }
137 
138  devtree = phys_to_virt(dt_phys);
139 
140  /* Check device tree validity */
141  if (be32_to_cpu(devtree->magic) != OF_DT_HEADER) {
142  early_print("\n"
143  "Error: invalid device tree blob at physical address 0x%p (virtual address 0x%p)\n"
144  "Expected 0x%x, found 0x%x\n"
145  "\nPlease check your bootloader.\n",
146  dt_phys, devtree, OF_DT_HEADER,
147  be32_to_cpu(devtree->magic));
148 
149  while (true)
150  cpu_relax();
151  }
152 
153  initial_boot_params = devtree;
154  dt_root = of_get_flat_dt_root();
155 
156  machine_name = of_get_flat_dt_prop(dt_root, "model", NULL);
157  if (!machine_name)
158  machine_name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
159  if (!machine_name)
160  machine_name = "<unknown>";
161  pr_info("Machine: %s\n", machine_name);
162 
163  /* Retrieve various information from the /chosen node */
164  of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
165  /* Initialize {size,address}-cells info */
166  of_scan_flat_dt(early_init_dt_scan_root, NULL);
167  /* Setup memory, calling early_init_dt_add_memory_arch */
168  of_scan_flat_dt(early_init_dt_scan_memory, NULL);
169 }
170 
172 {
173  base &= PAGE_MASK;
174  size &= PAGE_MASK;
175  if (base + size < PHYS_OFFSET) {
176  pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
177  base, base + size);
178  return;
179  }
180  if (base < PHYS_OFFSET) {
181  pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
182  base, PHYS_OFFSET);
183  size -= PHYS_OFFSET - base;
184  base = PHYS_OFFSET;
185  }
186  memblock_add(base, size);
187 }
188 
190 {
191  return __va(memblock_alloc(size, align));
192 }
193 
194 /*
195  * Limit the memory size that was specified via FDT.
196  */
197 static int __init early_mem(char *p)
198 {
200 
201  if (!p)
202  return 1;
203 
204  limit = memparse(p, &p) & PAGE_MASK;
205  pr_notice("Memory limited to %lldMB\n", limit >> 20);
206 
208 
209  return 0;
210 }
211 early_param("mem", early_mem);
212 
213 static void __init request_standard_resources(void)
214 {
215  struct memblock_region *region;
216  struct resource *res;
217 
218  kernel_code.start = virt_to_phys(_text);
219  kernel_code.end = virt_to_phys(_etext - 1);
220  kernel_data.start = virt_to_phys(_sdata);
221  kernel_data.end = virt_to_phys(_end - 1);
222 
223  for_each_memblock(memory, region) {
224  res = alloc_bootmem_low(sizeof(*res));
225  res->name = "System RAM";
226  res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
227  res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
229 
231 
232  if (kernel_code.start >= res->start &&
233  kernel_code.end <= res->end)
235  if (kernel_data.start >= res->start &&
236  kernel_data.end <= res->end)
238  }
239 }
240 
241 void __init setup_arch(char **cmdline_p)
242 {
243  setup_processor();
244 
245  setup_machine_fdt(__fdt_pointer);
246 
247  init_mm.start_code = (unsigned long) _text;
248  init_mm.end_code = (unsigned long) _etext;
249  init_mm.end_data = (unsigned long) _edata;
250  init_mm.brk = (unsigned long) _end;
251 
252  *cmdline_p = boot_command_line;
253 
255 
257 
258  paging_init();
259  request_standard_resources();
260 
261  unflatten_device_tree();
262 
263 #ifdef CONFIG_SMP
264  smp_init_cpus();
265 #endif
266 
267 #ifdef CONFIG_VT
268 #if defined(CONFIG_VGA_CONSOLE)
269  conswitchp = &vga_con;
270 #elif defined(CONFIG_DUMMY_CONSOLE)
272 #endif
273 #endif
274 }
275 
276 static DEFINE_PER_CPU(struct cpu, cpu_data);
277 
278 static int __init topology_init(void)
279 {
280  int i;
281 
283  struct cpu *cpu = &per_cpu(cpu_data, i);
284  cpu->hotpluggable = 1;
285  register_cpu(cpu, i);
286  }
287 
288  return 0;
289 }
290 subsys_initcall(topology_init);
291 
292 static const char *hwcap_str[] = {
293  "fp",
294  "asimd",
295  NULL
296 };
297 
298 static int c_show(struct seq_file *m, void *v)
299 {
300  int i;
301 
302  seq_printf(m, "Processor\t: %s rev %d (%s)\n",
303  cpu_name, read_cpuid_id() & 15, ELF_PLATFORM);
304 
306  /*
307  * glibc reads /proc/cpuinfo to determine the number of
308  * online processors, looking for lines beginning with
309  * "processor". Give glibc what it expects.
310  */
311 #ifdef CONFIG_SMP
312  seq_printf(m, "processor\t: %d\n", i);
313 #endif
314  seq_printf(m, "BogoMIPS\t: %lu.%02lu\n\n",
315  loops_per_jiffy / (500000UL/HZ),
316  loops_per_jiffy / (5000UL/HZ) % 100);
317  }
318 
319  /* dump out the processor features */
320  seq_puts(m, "Features\t: ");
321 
322  for (i = 0; hwcap_str[i]; i++)
323  if (elf_hwcap & (1 << i))
324  seq_printf(m, "%s ", hwcap_str[i]);
325 
326  seq_printf(m, "\nCPU implementer\t: 0x%02x\n", read_cpuid_id() >> 24);
327  seq_printf(m, "CPU architecture: AArch64\n");
328  seq_printf(m, "CPU variant\t: 0x%x\n", (read_cpuid_id() >> 20) & 15);
329  seq_printf(m, "CPU part\t: 0x%03x\n", (read_cpuid_id() >> 4) & 0xfff);
330  seq_printf(m, "CPU revision\t: %d\n", read_cpuid_id() & 15);
331 
332  seq_puts(m, "\n");
333 
334  seq_printf(m, "Hardware\t: %s\n", machine_name);
335 
336  return 0;
337 }
338 
339 static void *c_start(struct seq_file *m, loff_t *pos)
340 {
341  return *pos < 1 ? (void *)1 : NULL;
342 }
343 
344 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
345 {
346  ++*pos;
347  return NULL;
348 }
349 
350 static void c_stop(struct seq_file *m, void *v)
351 {
352 }
353 
354 const struct seq_operations cpuinfo_op = {
355  .start = c_start,
356  .next = c_next,
357  .stop = c_stop,
358  .show = c_show
359 };