xref: /openbmc/linux/arch/arm64/kernel/setup.c (revision 089a49b6)
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/clk-provider.h>
36 #include <linux/cpu.h>
37 #include <linux/interrupt.h>
38 #include <linux/smp.h>
39 #include <linux/fs.h>
40 #include <linux/proc_fs.h>
41 #include <linux/memblock.h>
42 #include <linux/of_fdt.h>
43 #include <linux/of_platform.h>
44 
45 #include <asm/cputype.h>
46 #include <asm/elf.h>
47 #include <asm/cputable.h>
48 #include <asm/sections.h>
49 #include <asm/setup.h>
50 #include <asm/smp_plat.h>
51 #include <asm/cacheflush.h>
52 #include <asm/tlbflush.h>
53 #include <asm/traps.h>
54 #include <asm/memblock.h>
55 #include <asm/psci.h>
56 
57 unsigned int processor_id;
58 EXPORT_SYMBOL(processor_id);
59 
60 unsigned long elf_hwcap __read_mostly;
61 EXPORT_SYMBOL_GPL(elf_hwcap);
62 
63 static const char *cpu_name;
64 static const char *machine_name;
65 phys_addr_t __fdt_pointer __initdata;
66 
67 /*
68  * Standard memory resources
69  */
70 static struct resource mem_res[] = {
71 	{
72 		.name = "Kernel code",
73 		.start = 0,
74 		.end = 0,
75 		.flags = IORESOURCE_MEM
76 	},
77 	{
78 		.name = "Kernel data",
79 		.start = 0,
80 		.end = 0,
81 		.flags = IORESOURCE_MEM
82 	}
83 };
84 
85 #define kernel_code mem_res[0]
86 #define kernel_data mem_res[1]
87 
88 void __init early_print(const char *str, ...)
89 {
90 	char buf[256];
91 	va_list ap;
92 
93 	va_start(ap, str);
94 	vsnprintf(buf, sizeof(buf), str, ap);
95 	va_end(ap);
96 
97 	printk("%s", buf);
98 }
99 
100 static void __init setup_processor(void)
101 {
102 	struct cpu_info *cpu_info;
103 
104 	/*
105 	 * locate processor in the list of supported processor
106 	 * types.  The linker builds this table for us from the
107 	 * entries in arch/arm/mm/proc.S
108 	 */
109 	cpu_info = lookup_processor_type(read_cpuid_id());
110 	if (!cpu_info) {
111 		printk("CPU configuration botched (ID %08x), unable to continue.\n",
112 		       read_cpuid_id());
113 		while (1);
114 	}
115 
116 	cpu_name = cpu_info->cpu_name;
117 
118 	printk("CPU: %s [%08x] revision %d\n",
119 	       cpu_name, read_cpuid_id(), read_cpuid_id() & 15);
120 
121 	sprintf(init_utsname()->machine, "aarch64");
122 	elf_hwcap = 0;
123 }
124 
125 static void __init setup_machine_fdt(phys_addr_t dt_phys)
126 {
127 	if (!dt_phys || !early_init_dt_scan(phys_to_virt(dt_phys))) {
128 		early_print("\n"
129 			"Error: invalid device tree blob at physical address 0x%p (virtual address 0x%p)\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 			dt_phys, phys_to_virt(dt_phys));
133 
134 		while (true)
135 			cpu_relax();
136 	}
137 
138 	machine_name = of_flat_dt_get_machine_name();
139 }
140 
141 /*
142  * Limit the memory size that was specified via FDT.
143  */
144 static int __init early_mem(char *p)
145 {
146 	phys_addr_t limit;
147 
148 	if (!p)
149 		return 1;
150 
151 	limit = memparse(p, &p) & PAGE_MASK;
152 	pr_notice("Memory limited to %lldMB\n", limit >> 20);
153 
154 	memblock_enforce_memory_limit(limit);
155 
156 	return 0;
157 }
158 early_param("mem", early_mem);
159 
160 static void __init request_standard_resources(void)
161 {
162 	struct memblock_region *region;
163 	struct resource *res;
164 
165 	kernel_code.start   = virt_to_phys(_text);
166 	kernel_code.end     = virt_to_phys(_etext - 1);
167 	kernel_data.start   = virt_to_phys(_sdata);
168 	kernel_data.end     = virt_to_phys(_end - 1);
169 
170 	for_each_memblock(memory, region) {
171 		res = alloc_bootmem_low(sizeof(*res));
172 		res->name  = "System RAM";
173 		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
174 		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
175 		res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
176 
177 		request_resource(&iomem_resource, res);
178 
179 		if (kernel_code.start >= res->start &&
180 		    kernel_code.end <= res->end)
181 			request_resource(res, &kernel_code);
182 		if (kernel_data.start >= res->start &&
183 		    kernel_data.end <= res->end)
184 			request_resource(res, &kernel_data);
185 	}
186 }
187 
188 u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
189 
190 void __init setup_arch(char **cmdline_p)
191 {
192 	setup_processor();
193 
194 	setup_machine_fdt(__fdt_pointer);
195 
196 	init_mm.start_code = (unsigned long) _text;
197 	init_mm.end_code   = (unsigned long) _etext;
198 	init_mm.end_data   = (unsigned long) _edata;
199 	init_mm.brk	   = (unsigned long) _end;
200 
201 	*cmdline_p = boot_command_line;
202 
203 	parse_early_param();
204 
205 	arm64_memblock_init();
206 
207 	paging_init();
208 	request_standard_resources();
209 
210 	unflatten_device_tree();
211 
212 	psci_init();
213 
214 	cpu_logical_map(0) = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;
215 #ifdef CONFIG_SMP
216 	smp_init_cpus();
217 #endif
218 
219 #ifdef CONFIG_VT
220 #if defined(CONFIG_VGA_CONSOLE)
221 	conswitchp = &vga_con;
222 #elif defined(CONFIG_DUMMY_CONSOLE)
223 	conswitchp = &dummy_con;
224 #endif
225 #endif
226 }
227 
228 static int __init arm64_device_init(void)
229 {
230 	of_clk_init(NULL);
231 	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
232 	return 0;
233 }
234 arch_initcall(arm64_device_init);
235 
236 static DEFINE_PER_CPU(struct cpu, cpu_data);
237 
238 static int __init topology_init(void)
239 {
240 	int i;
241 
242 	for_each_possible_cpu(i) {
243 		struct cpu *cpu = &per_cpu(cpu_data, i);
244 		cpu->hotpluggable = 1;
245 		register_cpu(cpu, i);
246 	}
247 
248 	return 0;
249 }
250 subsys_initcall(topology_init);
251 
252 static const char *hwcap_str[] = {
253 	"fp",
254 	"asimd",
255 	NULL
256 };
257 
258 static int c_show(struct seq_file *m, void *v)
259 {
260 	int i;
261 
262 	seq_printf(m, "Processor\t: %s rev %d (%s)\n",
263 		   cpu_name, read_cpuid_id() & 15, ELF_PLATFORM);
264 
265 	for_each_online_cpu(i) {
266 		/*
267 		 * glibc reads /proc/cpuinfo to determine the number of
268 		 * online processors, looking for lines beginning with
269 		 * "processor".  Give glibc what it expects.
270 		 */
271 #ifdef CONFIG_SMP
272 		seq_printf(m, "processor\t: %d\n", i);
273 #endif
274 	}
275 
276 	/* dump out the processor features */
277 	seq_puts(m, "Features\t: ");
278 
279 	for (i = 0; hwcap_str[i]; i++)
280 		if (elf_hwcap & (1 << i))
281 			seq_printf(m, "%s ", hwcap_str[i]);
282 
283 	seq_printf(m, "\nCPU implementer\t: 0x%02x\n", read_cpuid_id() >> 24);
284 	seq_printf(m, "CPU architecture: AArch64\n");
285 	seq_printf(m, "CPU variant\t: 0x%x\n", (read_cpuid_id() >> 20) & 15);
286 	seq_printf(m, "CPU part\t: 0x%03x\n", (read_cpuid_id() >> 4) & 0xfff);
287 	seq_printf(m, "CPU revision\t: %d\n", read_cpuid_id() & 15);
288 
289 	seq_puts(m, "\n");
290 
291 	seq_printf(m, "Hardware\t: %s\n", machine_name);
292 
293 	return 0;
294 }
295 
296 static void *c_start(struct seq_file *m, loff_t *pos)
297 {
298 	return *pos < 1 ? (void *)1 : NULL;
299 }
300 
301 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
302 {
303 	++*pos;
304 	return NULL;
305 }
306 
307 static void c_stop(struct seq_file *m, void *v)
308 {
309 }
310 
311 const struct seq_operations cpuinfo_op = {
312 	.start	= c_start,
313 	.next	= c_next,
314 	.stop	= c_stop,
315 	.show	= c_show
316 };
317