xref: /linux/arch/mips/kernel/setup.c (revision 24c776355f4097316a763005434ffff716aa21a8)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1995 Linus Torvalds
7  * Copyright (C) 1995 Waldorf Electronics
8  * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 01, 02, 03  Ralf Baechle
9  * Copyright (C) 1996 Stoned Elipot
10  * Copyright (C) 1999 Silicon Graphics, Inc.
11  * Copyright (C) 2000, 2001, 2002, 2007	 Maciej W. Rozycki
12  */
13 #include <linux/init.h>
14 #include <linux/cpu.h>
15 #include <linux/delay.h>
16 #include <linux/hex.h>
17 #include <linux/ioport.h>
18 #include <linux/export.h>
19 #include <linux/memblock.h>
20 #include <linux/initrd.h>
21 #include <linux/root_dev.h>
22 #include <linux/highmem.h>
23 #include <linux/console.h>
24 #include <linux/pfn.h>
25 #include <linux/debugfs.h>
26 #include <linux/kexec.h>
27 #include <linux/sizes.h>
28 #include <linux/device.h>
29 #include <linux/dma-map-ops.h>
30 #include <linux/decompress/generic.h>
31 #include <linux/of_fdt.h>
32 #include <linux/dmi.h>
33 #include <linux/crash_dump.h>
34 
35 #include <asm/addrspace.h>
36 #include <asm/bootinfo.h>
37 #include <asm/bugs.h>
38 #include <asm/cache.h>
39 #include <asm/cdmm.h>
40 #include <asm/cpu.h>
41 #include <asm/debug.h>
42 #include <asm/mmzone.h>
43 #include <asm/sections.h>
44 #include <asm/setup.h>
45 #include <asm/smp-ops.h>
46 #include <asm/mips-cps.h>
47 #include <asm/prom.h>
48 #include <asm/fw/fw.h>
49 
50 #ifdef CONFIG_MIPS_ELF_APPENDED_DTB
51 char __section(".appended_dtb") __appended_dtb[0x100000];
52 #endif /* CONFIG_MIPS_ELF_APPENDED_DTB */
53 
54 struct cpuinfo_mips cpu_data[NR_CPUS] __read_mostly;
55 
56 EXPORT_SYMBOL(cpu_data);
57 
58 /*
59  * Setup information
60  *
61  * These are initialized so they are in the .data section
62  */
63 unsigned long mips_machtype __read_mostly = MACH_UNKNOWN;
64 
65 EXPORT_SYMBOL(mips_machtype);
66 
67 static char __initdata command_line[COMMAND_LINE_SIZE];
68 char __initdata arcs_cmdline[COMMAND_LINE_SIZE];
69 
70 #ifdef CONFIG_CMDLINE_BOOL
71 static const char builtin_cmdline[] __initconst = CONFIG_CMDLINE;
72 #else
73 static const char builtin_cmdline[] __initconst = "";
74 #endif
75 
76 /*
77  * mips_io_port_base is the begin of the address space to which x86 style
78  * I/O ports are mapped.
79  */
80 unsigned long mips_io_port_base = -1;
81 EXPORT_SYMBOL(mips_io_port_base);
82 
83 static struct resource code_resource = { .name = "Kernel code", };
84 static struct resource data_resource = { .name = "Kernel data", };
85 static struct resource bss_resource = { .name = "Kernel bss", };
86 
87 unsigned long __kaslr_offset __ro_after_init;
88 EXPORT_SYMBOL(__kaslr_offset);
89 
90 static void *detect_magic __initdata = detect_memory_region;
91 
92 #ifdef CONFIG_MIPS_AUTO_PFN_OFFSET
93 unsigned long ARCH_PFN_OFFSET;
94 EXPORT_SYMBOL(ARCH_PFN_OFFSET);
95 #endif
96 
97 void __init detect_memory_region(phys_addr_t start, phys_addr_t sz_min, phys_addr_t sz_max)
98 {
99 	void *dm = &detect_magic;
100 	phys_addr_t size;
101 
102 	for (size = sz_min; size < sz_max; size <<= 1) {
103 		if (!memcmp(dm, dm + size, sizeof(detect_magic)))
104 			break;
105 	}
106 
107 	pr_debug("Memory: %lluMB of RAM detected at 0x%llx (min: %lluMB, max: %lluMB)\n",
108 		((unsigned long long) size) / SZ_1M,
109 		(unsigned long long) start,
110 		((unsigned long long) sz_min) / SZ_1M,
111 		((unsigned long long) sz_max) / SZ_1M);
112 
113 	memblock_add(start, size);
114 }
115 
116 /*
117  * Manage initrd
118  */
119 #ifdef CONFIG_BLK_DEV_INITRD
120 
121 static int __init rd_start_early(char *p)
122 {
123 	unsigned long start = memparse(p, &p);
124 
125 #ifdef CONFIG_64BIT
126 	/* Guess if the sign extension was forgotten by bootloader */
127 	if (start < XKPHYS)
128 		start = (int)start;
129 #endif
130 	initrd_start = start;
131 	initrd_end += start;
132 	return 0;
133 }
134 early_param("rd_start", rd_start_early);
135 
136 static int __init rd_size_early(char *p)
137 {
138 	initrd_end += memparse(p, &p);
139 	return 0;
140 }
141 early_param("rd_size", rd_size_early);
142 
143 /* it returns the next free pfn after initrd */
144 static unsigned long __init init_initrd(void)
145 {
146 	unsigned long end;
147 
148 	/*
149 	 * Board specific code or command line parser should have
150 	 * already set up initrd_start and initrd_end. In these cases
151 	 * perform sanity checks and use them if all looks good.
152 	 */
153 	if (!initrd_start || initrd_end <= initrd_start)
154 		goto disable;
155 
156 	if (initrd_start & ~PAGE_MASK) {
157 		pr_err("initrd start must be page aligned\n");
158 		goto disable;
159 	}
160 
161 	/*
162 	 * Sanitize initrd addresses. For example firmware
163 	 * can't guess if they need to pass them through
164 	 * 64-bits values if the kernel has been built in pure
165 	 * 32-bit. We need also to switch from KSEG0 to XKPHYS
166 	 * addresses now, so the code can now safely use __pa().
167 	 */
168 	end = __pa(initrd_end);
169 	initrd_end = (unsigned long)__va(end);
170 	initrd_start = (unsigned long)__va(__pa(initrd_start));
171 
172 	if (initrd_start < PAGE_OFFSET) {
173 		pr_err("initrd start < PAGE_OFFSET\n");
174 		goto disable;
175 	}
176 
177 	ROOT_DEV = Root_RAM0;
178 	return PFN_UP(end);
179 disable:
180 	initrd_start = 0;
181 	initrd_end = 0;
182 	return 0;
183 }
184 
185 /* In some conditions (e.g. big endian bootloader with a little endian
186    kernel), the initrd might appear byte swapped.  Try to detect this and
187    byte swap it if needed.  */
188 static void __init maybe_bswap_initrd(void)
189 {
190 #if defined(CONFIG_CPU_CAVIUM_OCTEON)
191 	u64 buf;
192 
193 	/* Check for CPIO signature */
194 	if (!memcmp((void *)initrd_start, "070701", 6))
195 		return;
196 
197 	/* Check for compressed initrd */
198 	if (decompress_method((unsigned char *)initrd_start, 8, NULL))
199 		return;
200 
201 	/* Try again with a byte swapped header */
202 	buf = swab64p((u64 *)initrd_start);
203 	if (!memcmp(&buf, "070701", 6) ||
204 	    decompress_method((unsigned char *)(&buf), 8, NULL)) {
205 		unsigned long i;
206 
207 		pr_info("Byteswapped initrd detected\n");
208 		for (i = initrd_start; i < ALIGN(initrd_end, 8); i += 8)
209 			swab64s((u64 *)i);
210 	}
211 #endif
212 }
213 
214 static void __init finalize_initrd(void)
215 {
216 	unsigned long size = initrd_end - initrd_start;
217 
218 	if (size == 0) {
219 		printk(KERN_INFO "Initrd not found or empty");
220 		goto disable;
221 	}
222 	if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
223 		printk(KERN_ERR "Initrd extends beyond end of memory");
224 		goto disable;
225 	}
226 
227 	maybe_bswap_initrd();
228 
229 	memblock_reserve(__pa(initrd_start), size);
230 	initrd_below_start_ok = 1;
231 
232 	pr_info("Initial ramdisk at: 0x%lx (%lu bytes)\n",
233 		initrd_start, size);
234 	return;
235 disable:
236 	printk(KERN_CONT " - disabling initrd\n");
237 	initrd_start = 0;
238 	initrd_end = 0;
239 }
240 
241 #else  /* !CONFIG_BLK_DEV_INITRD */
242 
243 static unsigned long __init init_initrd(void)
244 {
245 	return 0;
246 }
247 
248 #define finalize_initrd()	do {} while (0)
249 
250 #endif
251 
252 /*
253  * Initialize the bootmem allocator. It also setup initrd related data
254  * if needed.
255  */
256 #if defined(CONFIG_SGI_IP27) || (defined(CONFIG_CPU_LOONGSON64) && defined(CONFIG_NUMA))
257 
258 static void __init bootmem_init(void)
259 {
260 	init_initrd();
261 	finalize_initrd();
262 }
263 
264 #else  /* !CONFIG_SGI_IP27 */
265 
266 static void __init bootmem_init(void)
267 {
268 	phys_addr_t ramstart, ramend;
269 	unsigned long start, end;
270 	int i;
271 
272 	ramstart = memblock_start_of_DRAM();
273 	ramend = memblock_end_of_DRAM();
274 
275 	/*
276 	 * Sanity check any INITRD first. We don't take it into account
277 	 * for bootmem setup initially, rely on the end-of-kernel-code
278 	 * as our memory range starting point. Once bootmem is inited we
279 	 * will reserve the area used for the initrd.
280 	 */
281 	init_initrd();
282 
283 	/* Reserve memory occupied by kernel. */
284 	memblock_reserve(__pa_symbol(&_text),
285 			__pa_symbol(&_end) - __pa_symbol(&_text));
286 
287 	/* max_low_pfn is not a number of pages but the end pfn of low mem */
288 
289 #ifdef CONFIG_MIPS_AUTO_PFN_OFFSET
290 	ARCH_PFN_OFFSET = PFN_UP(ramstart);
291 #else
292 	/*
293 	 * Reserve any memory between the start of RAM and PHYS_OFFSET
294 	 */
295 	if (ramstart > PHYS_OFFSET)
296 		memblock_reserve(PHYS_OFFSET, ramstart - PHYS_OFFSET);
297 
298 	if (PFN_UP(ramstart) > ARCH_PFN_OFFSET) {
299 		pr_info("Wasting %lu bytes for tracking %lu unused pages\n",
300 			(unsigned long)((PFN_UP(ramstart) - ARCH_PFN_OFFSET) * sizeof(struct page)),
301 			(unsigned long)(PFN_UP(ramstart) - ARCH_PFN_OFFSET));
302 	}
303 #endif
304 
305 	min_low_pfn = ARCH_PFN_OFFSET;
306 	max_pfn = PFN_DOWN(ramend);
307 	for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, NULL) {
308 		/*
309 		 * Skip highmem here so we get an accurate max_low_pfn if low
310 		 * memory stops short of high memory.
311 		 * If the region overlaps HIGHMEM_START, end is clipped so
312 		 * max_pfn excludes the highmem portion.
313 		 */
314 		if (start >= PFN_DOWN(HIGHMEM_START))
315 			continue;
316 		if (end > PFN_DOWN(HIGHMEM_START))
317 			end = PFN_DOWN(HIGHMEM_START);
318 		if (end > max_low_pfn)
319 			max_low_pfn = end;
320 	}
321 
322 	if (min_low_pfn >= max_low_pfn)
323 		panic("Incorrect memory mapping !!!");
324 
325 	if (max_pfn > PFN_DOWN(HIGHMEM_START)) {
326 		max_low_pfn = PFN_DOWN(HIGHMEM_START);
327 #ifdef CONFIG_HIGHMEM
328 		highstart_pfn = max_low_pfn;
329 		highend_pfn = max_pfn;
330 #else
331 		max_pfn = max_low_pfn;
332 #endif
333 	}
334 
335 	/*
336 	 * Reserve initrd memory if needed.
337 	 */
338 	finalize_initrd();
339 }
340 
341 #endif	/* CONFIG_SGI_IP27 */
342 
343 static int usermem __initdata;
344 
345 static int __init early_parse_mem(char *p)
346 {
347 	phys_addr_t start, size;
348 
349 	if (!p) {
350 		pr_err("mem parameter is empty, do nothing\n");
351 		return -EINVAL;
352 	}
353 
354 	/*
355 	 * If a user specifies memory size, we
356 	 * blow away any automatically generated
357 	 * size.
358 	 */
359 	if (usermem == 0) {
360 		usermem = 1;
361 		memblock_remove(memblock_start_of_DRAM(),
362 			memblock_end_of_DRAM() - memblock_start_of_DRAM());
363 	}
364 	start = 0;
365 	size = memparse(p, &p);
366 	if (*p == '@')
367 		start = memparse(p + 1, &p);
368 
369 	if (IS_ENABLED(CONFIG_NUMA))
370 		memblock_add_node(start, size, pa_to_nid(start), MEMBLOCK_NONE);
371 	else
372 		memblock_add(start, size);
373 
374 	return 0;
375 }
376 early_param("mem", early_parse_mem);
377 
378 static int __init early_parse_memmap(char *p)
379 {
380 	char *oldp;
381 	u64 start_at, mem_size;
382 
383 	if (!p)
384 		return -EINVAL;
385 
386 	if (!strncmp(p, "exactmap", 8)) {
387 		pr_err("\"memmap=exactmap\" invalid on MIPS\n");
388 		return 0;
389 	}
390 
391 	oldp = p;
392 	mem_size = memparse(p, &p);
393 	if (p == oldp)
394 		return -EINVAL;
395 
396 	if (*p == '@') {
397 		start_at = memparse(p+1, &p);
398 		memblock_add(start_at, mem_size);
399 	} else if (*p == '#') {
400 		pr_err("\"memmap=nn#ss\" (force ACPI data) invalid on MIPS\n");
401 		return -EINVAL;
402 	} else if (*p == '$') {
403 		start_at = memparse(p+1, &p);
404 		memblock_add(start_at, mem_size);
405 		memblock_reserve(start_at, mem_size);
406 	} else {
407 		pr_err("\"memmap\" invalid format!\n");
408 		return -EINVAL;
409 	}
410 
411 	if (*p == '\0') {
412 		usermem = 1;
413 		return 0;
414 	} else
415 		return -EINVAL;
416 }
417 early_param("memmap", early_parse_memmap);
418 
419 static void __init mips_reserve_vmcore(void)
420 {
421 #ifdef CONFIG_PROC_VMCORE
422 	phys_addr_t start, end;
423 	u64 i;
424 
425 	if (!elfcorehdr_size) {
426 		for_each_mem_range(i, &start, &end) {
427 			if (elfcorehdr_addr >= start && elfcorehdr_addr < end) {
428 				/*
429 				 * Reserve from the elf core header to the end of
430 				 * the memory segment, that should all be kdump
431 				 * reserved memory.
432 				 */
433 				elfcorehdr_size = end - elfcorehdr_addr;
434 				break;
435 			}
436 		}
437 	}
438 
439 	pr_info("Reserving %ldKB of memory at %ldKB for kdump\n",
440 		(unsigned long)elfcorehdr_size >> 10, (unsigned long)elfcorehdr_addr >> 10);
441 
442 	memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
443 #endif
444 }
445 
446 /* 64M alignment for crash kernel regions */
447 #define CRASH_ALIGN	SZ_64M
448 #define CRASH_ADDR_MAX	SZ_512M
449 
450 static void __init mips_parse_crashkernel(void)
451 {
452 	unsigned long long total_mem;
453 	unsigned long long crash_size, crash_base;
454 	int ret;
455 
456 	if (!IS_ENABLED(CONFIG_CRASH_RESERVE))
457 		return;
458 
459 	total_mem = memblock_phys_mem_size();
460 	ret = parse_crashkernel(boot_command_line, total_mem,
461 				&crash_size, &crash_base,
462 				NULL, NULL, NULL);
463 	if (ret != 0 || crash_size <= 0)
464 		return;
465 
466 	if (crash_base <= 0) {
467 		crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN,
468 						       CRASH_ALIGN,
469 						       CRASH_ADDR_MAX);
470 		if (!crash_base) {
471 			pr_warn("crashkernel reservation failed - No suitable area found.\n");
472 			return;
473 		}
474 	} else {
475 		unsigned long long start;
476 
477 		start = memblock_phys_alloc_range(crash_size, 1,
478 						  crash_base,
479 						  crash_base + crash_size);
480 		if (start != crash_base) {
481 			pr_warn("Invalid memory region reserved for crash kernel\n");
482 			return;
483 		}
484 	}
485 
486 	crashk_res.start = crash_base;
487 	crashk_res.end	 = crash_base + crash_size - 1;
488 }
489 
490 static void __init request_crashkernel(struct resource *res)
491 {
492 	int ret;
493 
494 	if (!IS_ENABLED(CONFIG_CRASH_RESERVE))
495 		return;
496 
497 	if (crashk_res.start == crashk_res.end)
498 		return;
499 
500 	ret = request_resource(res, &crashk_res);
501 	if (!ret)
502 		pr_info("Reserving %ldMB of memory at %ldMB for crashkernel\n",
503 			(unsigned long)(resource_size(&crashk_res) >> 20),
504 			(unsigned long)(crashk_res.start  >> 20));
505 }
506 
507 static void __init check_kernel_sections_mem(void)
508 {
509 	phys_addr_t start = __pa_symbol(&_text);
510 	phys_addr_t size = __pa_symbol(&_end) - start;
511 
512 	if (!memblock_is_region_memory(start, size)) {
513 		pr_info("Kernel sections are not in the memory maps\n");
514 		memblock_add(start, size);
515 	}
516 }
517 
518 static void __init bootcmdline_append(const char *s, size_t max)
519 {
520 	if (!s[0] || !max)
521 		return;
522 
523 	if (boot_command_line[0])
524 		strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
525 
526 	strlcat(boot_command_line, s, max);
527 }
528 
529 #ifdef CONFIG_OF_EARLY_FLATTREE
530 
531 static int __init bootcmdline_scan_chosen(unsigned long node, const char *uname,
532 					  int depth, void *data)
533 {
534 	bool *dt_bootargs = data;
535 	const char *p;
536 	int l;
537 
538 	if (depth != 1 || !data ||
539 	    (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
540 		return 0;
541 
542 	p = of_get_flat_dt_prop(node, "bootargs", &l);
543 	if (p != NULL && l > 0) {
544 		bootcmdline_append(p, min(l, COMMAND_LINE_SIZE));
545 		*dt_bootargs = true;
546 	}
547 
548 	return 1;
549 }
550 
551 #endif /* CONFIG_OF_EARLY_FLATTREE */
552 
553 static void __init bootcmdline_init(void)
554 {
555 	bool dt_bootargs = false;
556 
557 	/*
558 	 * If CMDLINE_OVERRIDE is enabled then initializing the command line is
559 	 * trivial - we simply use the built-in command line unconditionally &
560 	 * unmodified.
561 	 */
562 	if (IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
563 		strscpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
564 		return;
565 	}
566 
567 	/*
568 	 * If the user specified a built-in command line &
569 	 * MIPS_CMDLINE_BUILTIN_EXTEND, then the built-in command line is
570 	 * prepended to arguments from the bootloader or DT so we'll copy them
571 	 * to the start of boot_command_line here. Otherwise, empty
572 	 * boot_command_line to undo anything early_init_dt_scan_chosen() did.
573 	 */
574 	if (IS_ENABLED(CONFIG_MIPS_CMDLINE_BUILTIN_EXTEND))
575 		strscpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
576 	else
577 		boot_command_line[0] = 0;
578 
579 #ifdef CONFIG_OF_EARLY_FLATTREE
580 	/*
581 	 * If we're configured to take boot arguments from DT, look for those
582 	 * now.
583 	 */
584 	if (IS_ENABLED(CONFIG_MIPS_CMDLINE_FROM_DTB) ||
585 	    IS_ENABLED(CONFIG_MIPS_CMDLINE_DTB_EXTEND))
586 		of_scan_flat_dt(bootcmdline_scan_chosen, &dt_bootargs);
587 #endif
588 
589 	/*
590 	 * If we didn't get any arguments from DT (regardless of whether that's
591 	 * because we weren't configured to look for them, or because we looked
592 	 * & found none) then we'll take arguments from the bootloader.
593 	 * plat_mem_setup() should have filled arcs_cmdline with arguments from
594 	 * the bootloader.
595 	 */
596 	if (IS_ENABLED(CONFIG_MIPS_CMDLINE_DTB_EXTEND) || !dt_bootargs)
597 		bootcmdline_append(arcs_cmdline, COMMAND_LINE_SIZE);
598 
599 	/*
600 	 * If the user specified a built-in command line & we didn't already
601 	 * prepend it, we append it to boot_command_line here.
602 	 */
603 	if (IS_ENABLED(CONFIG_CMDLINE_BOOL) &&
604 	    !IS_ENABLED(CONFIG_MIPS_CMDLINE_BUILTIN_EXTEND))
605 		bootcmdline_append(builtin_cmdline, COMMAND_LINE_SIZE);
606 }
607 
608 /*
609  * arch_mem_init - initialize memory management subsystem
610  *
611  *  o plat_mem_setup() detects the memory configuration and will record detected
612  *    memory areas using memblock_add.
613  *
614  * At this stage the memory configuration of the system is known to the
615  * kernel but generic memory management system is still entirely uninitialized.
616  *
617  *  o bootmem_init()
618  *  o sparse_init()
619  *  o paging_init()
620  *  o dma_contiguous_reserve()
621  *
622  * At this stage the bootmem allocator is ready to use.
623  *
624  * NOTE: historically plat_mem_setup did the entire platform initialization.
625  *	 This was rather impractical because it meant plat_mem_setup had to
626  * get away without any kind of memory allocator.  To keep old code from
627  * breaking plat_setup was just renamed to plat_mem_setup and a second platform
628  * initialization hook for anything else was introduced.
629  */
630 static void __init arch_mem_init(char **cmdline_p)
631 {
632 	/* call board setup routine */
633 	plat_mem_setup();
634 	memblock_set_bottom_up(true);
635 
636 	bootcmdline_init();
637 	strscpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
638 	*cmdline_p = command_line;
639 
640 	parse_early_param();
641 
642 	if (usermem)
643 		pr_info("User-defined physical RAM map overwrite\n");
644 
645 	check_kernel_sections_mem();
646 
647 	early_init_fdt_reserve_self();
648 	early_init_fdt_scan_reserved_mem();
649 
650 #ifndef CONFIG_NUMA
651 	memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
652 #endif
653 	bootmem_init();
654 
655 	/*
656 	 * Prevent memblock from allocating high memory.
657 	 * This cannot be done before max_low_pfn is detected, so up
658 	 * to this point is possible to only reserve physical memory
659 	 * with memblock_reserve; memblock_alloc* can be used
660 	 * only after this point
661 	 */
662 	memblock_set_current_limit(PFN_PHYS(max_low_pfn));
663 
664 	mips_reserve_vmcore();
665 
666 	mips_parse_crashkernel();
667 	device_tree_init();
668 
669 	/*
670 	 * In order to reduce the possibility of kernel panic when failed to
671 	 * get IO TLB memory under CONFIG_SWIOTLB, it is better to allocate
672 	 * low memory as small as possible before plat_swiotlb_setup(), so
673 	 * make sparse_init() using top-down allocation.
674 	 */
675 	memblock_set_bottom_up(false);
676 	sparse_init();
677 	memblock_set_bottom_up(true);
678 
679 	plat_swiotlb_setup();
680 
681 	dma_contiguous_reserve(PFN_PHYS(max_low_pfn));
682 
683 	/* Reserve for hibernation. */
684 	memblock_reserve(__pa_symbol(&__nosave_begin),
685 		__pa_symbol(&__nosave_end) - __pa_symbol(&__nosave_begin));
686 
687 	early_memtest(PFN_PHYS(ARCH_PFN_OFFSET), PFN_PHYS(max_low_pfn));
688 }
689 
690 static void __init resource_init(void)
691 {
692 	phys_addr_t start, end;
693 	u64 i;
694 
695 	if (UNCAC_BASE != IO_BASE)
696 		return;
697 
698 	code_resource.start = __pa_symbol(&_text);
699 	code_resource.end = __pa_symbol(&_etext) - 1;
700 	data_resource.start = __pa_symbol(&_etext);
701 	data_resource.end = __pa_symbol(&_edata) - 1;
702 	bss_resource.start = __pa_symbol(&__bss_start);
703 	bss_resource.end = __pa_symbol(&__bss_stop) - 1;
704 
705 	for_each_mem_range(i, &start, &end) {
706 		struct resource *res;
707 
708 		res = memblock_alloc_or_panic(sizeof(struct resource), SMP_CACHE_BYTES);
709 
710 		res->start = start;
711 		/*
712 		 * In memblock, end points to the first byte after the
713 		 * range while in resourses, end points to the last byte in
714 		 * the range.
715 		 */
716 		res->end = end - 1;
717 		res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
718 		res->name = "System RAM";
719 
720 		request_resource(&iomem_resource, res);
721 
722 		/*
723 		 *  We don't know which RAM region contains kernel data,
724 		 *  so we try it repeatedly and let the resource manager
725 		 *  test it.
726 		 */
727 		request_resource(res, &code_resource);
728 		request_resource(res, &data_resource);
729 		request_resource(res, &bss_resource);
730 		request_crashkernel(res);
731 	}
732 }
733 
734 #ifdef CONFIG_SMP
735 static void __init prefill_possible_map(void)
736 {
737 	int i, possible = num_possible_cpus();
738 
739 	if (possible > nr_cpu_ids)
740 		possible = nr_cpu_ids;
741 
742 	for (i = 0; i < possible; i++)
743 		set_cpu_possible(i, true);
744 	for (; i < NR_CPUS; i++)
745 		set_cpu_possible(i, false);
746 
747 	set_nr_cpu_ids(possible);
748 }
749 #else
750 static inline void prefill_possible_map(void) {}
751 #endif
752 
753 static void __init setup_rng_seed(void)
754 {
755 	char *rng_seed_hex = fw_getenv("rngseed");
756 	u8 rng_seed[512];
757 	size_t len;
758 
759 	if (!rng_seed_hex)
760 		return;
761 
762 	len = min(sizeof(rng_seed), strlen(rng_seed_hex) / 2);
763 	if (hex2bin(rng_seed, rng_seed_hex, len))
764 		return;
765 
766 	add_bootloader_randomness(rng_seed, len);
767 	memzero_explicit(rng_seed, len);
768 	memzero_explicit(rng_seed_hex, len * 2);
769 }
770 
771 void __init setup_arch(char **cmdline_p)
772 {
773 	cpu_probe();
774 	mips_cm_probe();
775 	prom_init();
776 
777 	setup_early_fdc_console();
778 #ifdef CONFIG_EARLY_PRINTK
779 	setup_early_printk();
780 #endif
781 	cpu_report();
782 	if (IS_ENABLED(CONFIG_CPU_R4X00_BUGS64))
783 		check_bugs64_early();
784 
785 	arch_mem_init(cmdline_p);
786 	dmi_setup();
787 
788 	resource_init();
789 	plat_smp_setup();
790 	prefill_possible_map();
791 
792 	cpu_cache_init();
793 	paging_init();
794 
795 	memblock_dump_all();
796 
797 	setup_rng_seed();
798 }
799 
800 unsigned long kernelsp[NR_CPUS];
801 unsigned long fw_arg0, fw_arg1, fw_arg2, fw_arg3;
802 
803 #ifdef CONFIG_DEBUG_FS
804 struct dentry *mips_debugfs_dir;
805 static int __init debugfs_mips(void)
806 {
807 	mips_debugfs_dir = debugfs_create_dir("mips", NULL);
808 	return 0;
809 }
810 arch_initcall(debugfs_mips);
811 #endif
812 
813 #ifdef CONFIG_DMA_NONCOHERENT
814 static int __init setcoherentio(char *str)
815 {
816 	dma_default_coherent = true;
817 	pr_info("Hardware DMA cache coherency (command line)\n");
818 	return 0;
819 }
820 early_param("coherentio", setcoherentio);
821 
822 static int __init setnocoherentio(char *str)
823 {
824 	dma_default_coherent = false;
825 	pr_info("Software DMA cache coherency (command line)\n");
826 	return 0;
827 }
828 early_param("nocoherentio", setnocoherentio);
829 #endif
830 
831 void __init arch_cpu_finalize_init(void)
832 {
833 	unsigned int cpu = smp_processor_id();
834 
835 	cpu_data[cpu].udelay_val = loops_per_jiffy;
836 	check_bugs32();
837 
838 	if (IS_ENABLED(CONFIG_CPU_R4X00_BUGS64))
839 		check_bugs64();
840 }
841