xref: /openbmc/linux/arch/mips/kernel/setup.c (revision 2a954832)
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/ioport.h>
15 #include <linux/export.h>
16 #include <linux/screen_info.h>
17 #include <linux/memblock.h>
18 #include <linux/initrd.h>
19 #include <linux/root_dev.h>
20 #include <linux/highmem.h>
21 #include <linux/console.h>
22 #include <linux/pfn.h>
23 #include <linux/debugfs.h>
24 #include <linux/kexec.h>
25 #include <linux/sizes.h>
26 #include <linux/device.h>
27 #include <linux/dma-map-ops.h>
28 #include <linux/decompress/generic.h>
29 #include <linux/of_fdt.h>
30 #include <linux/dmi.h>
31 #include <linux/crash_dump.h>
32 
33 #include <asm/addrspace.h>
34 #include <asm/bootinfo.h>
35 #include <asm/bugs.h>
36 #include <asm/cache.h>
37 #include <asm/cdmm.h>
38 #include <asm/cpu.h>
39 #include <asm/debug.h>
40 #include <asm/mmzone.h>
41 #include <asm/sections.h>
42 #include <asm/setup.h>
43 #include <asm/smp-ops.h>
44 #include <asm/prom.h>
45 #include <asm/fw/fw.h>
46 
47 #ifdef CONFIG_MIPS_ELF_APPENDED_DTB
48 char __section(".appended_dtb") __appended_dtb[0x100000];
49 #endif /* CONFIG_MIPS_ELF_APPENDED_DTB */
50 
51 struct cpuinfo_mips cpu_data[NR_CPUS] __read_mostly;
52 
53 EXPORT_SYMBOL(cpu_data);
54 
55 #ifdef CONFIG_VT
56 struct screen_info screen_info;
57 #endif
58 
59 /*
60  * Setup information
61  *
62  * These are initialized so they are in the .data section
63  */
64 unsigned long mips_machtype __read_mostly = MACH_UNKNOWN;
65 
66 EXPORT_SYMBOL(mips_machtype);
67 
68 static char __initdata command_line[COMMAND_LINE_SIZE];
69 char __initdata arcs_cmdline[COMMAND_LINE_SIZE];
70 
71 #ifdef CONFIG_CMDLINE_BOOL
72 static const char builtin_cmdline[] __initconst = CONFIG_CMDLINE;
73 #else
74 static const char builtin_cmdline[] __initconst = "";
75 #endif
76 
77 /*
78  * mips_io_port_base is the begin of the address space to which x86 style
79  * I/O ports are mapped.
80  */
81 unsigned long mips_io_port_base = -1;
82 EXPORT_SYMBOL(mips_io_port_base);
83 
84 static struct resource code_resource = { .name = "Kernel code", };
85 static struct resource data_resource = { .name = "Kernel data", };
86 static struct resource bss_resource = { .name = "Kernel bss", };
87 
88 unsigned long __kaslr_offset __ro_after_init;
89 EXPORT_SYMBOL(__kaslr_offset);
90 
91 static void *detect_magic __initdata = detect_memory_region;
92 
93 #ifdef CONFIG_MIPS_AUTO_PFN_OFFSET
94 unsigned long ARCH_PFN_OFFSET;
95 EXPORT_SYMBOL(ARCH_PFN_OFFSET);
96 #endif
97 
98 void __init detect_memory_region(phys_addr_t start, phys_addr_t sz_min, phys_addr_t sz_max)
99 {
100 	void *dm = &detect_magic;
101 	phys_addr_t size;
102 
103 	for (size = sz_min; size < sz_max; size <<= 1) {
104 		if (!memcmp(dm, dm + size, sizeof(detect_magic)))
105 			break;
106 	}
107 
108 	pr_debug("Memory: %lluMB of RAM detected at 0x%llx (min: %lluMB, max: %lluMB)\n",
109 		((unsigned long long) size) / SZ_1M,
110 		(unsigned long long) start,
111 		((unsigned long long) sz_min) / SZ_1M,
112 		((unsigned long long) sz_max) / SZ_1M);
113 
114 	memblock_add(start, size);
115 }
116 
117 /*
118  * Manage initrd
119  */
120 #ifdef CONFIG_BLK_DEV_INITRD
121 
122 static int __init rd_start_early(char *p)
123 {
124 	unsigned long start = memparse(p, &p);
125 
126 #ifdef CONFIG_64BIT
127 	/* Guess if the sign extension was forgotten by bootloader */
128 	if (start < XKPHYS)
129 		start = (int)start;
130 #endif
131 	initrd_start = start;
132 	initrd_end += start;
133 	return 0;
134 }
135 early_param("rd_start", rd_start_early);
136 
137 static int __init rd_size_early(char *p)
138 {
139 	initrd_end += memparse(p, &p);
140 	return 0;
141 }
142 early_param("rd_size", rd_size_early);
143 
144 /* it returns the next free pfn after initrd */
145 static unsigned long __init init_initrd(void)
146 {
147 	unsigned long end;
148 
149 	/*
150 	 * Board specific code or command line parser should have
151 	 * already set up initrd_start and initrd_end. In these cases
152 	 * perfom sanity checks and use them if all looks good.
153 	 */
154 	if (!initrd_start || initrd_end <= initrd_start)
155 		goto disable;
156 
157 	if (initrd_start & ~PAGE_MASK) {
158 		pr_err("initrd start must be page aligned\n");
159 		goto disable;
160 	}
161 	if (initrd_start < PAGE_OFFSET) {
162 		pr_err("initrd start < PAGE_OFFSET\n");
163 		goto disable;
164 	}
165 
166 	/*
167 	 * Sanitize initrd addresses. For example firmware
168 	 * can't guess if they need to pass them through
169 	 * 64-bits values if the kernel has been built in pure
170 	 * 32-bit. We need also to switch from KSEG0 to XKPHYS
171 	 * addresses now, so the code can now safely use __pa().
172 	 */
173 	end = __pa(initrd_end);
174 	initrd_end = (unsigned long)__va(end);
175 	initrd_start = (unsigned long)__va(__pa(initrd_start));
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 #ifdef CONFIG_HIGHMEM
327 		highstart_pfn = PFN_DOWN(HIGHMEM_START);
328 		highend_pfn = max_pfn;
329 #else
330 		max_low_pfn = PFN_DOWN(HIGHMEM_START);
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 #ifdef CONFIG_KEXEC
447 
448 /* 64M alignment for crash kernel regions */
449 #define CRASH_ALIGN	SZ_64M
450 #define CRASH_ADDR_MAX	SZ_512M
451 
452 static void __init mips_parse_crashkernel(void)
453 {
454 	unsigned long long total_mem;
455 	unsigned long long crash_size, crash_base;
456 	int ret;
457 
458 	total_mem = memblock_phys_mem_size();
459 	ret = parse_crashkernel(boot_command_line, total_mem,
460 				&crash_size, &crash_base);
461 	if (ret != 0 || crash_size <= 0)
462 		return;
463 
464 	if (crash_base <= 0) {
465 		crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN,
466 						       CRASH_ALIGN,
467 						       CRASH_ADDR_MAX);
468 		if (!crash_base) {
469 			pr_warn("crashkernel reservation failed - No suitable area found.\n");
470 			return;
471 		}
472 	} else {
473 		unsigned long long start;
474 
475 		start = memblock_phys_alloc_range(crash_size, 1,
476 						  crash_base,
477 						  crash_base + crash_size);
478 		if (start != crash_base) {
479 			pr_warn("Invalid memory region reserved for crash kernel\n");
480 			return;
481 		}
482 	}
483 
484 	crashk_res.start = crash_base;
485 	crashk_res.end	 = crash_base + crash_size - 1;
486 }
487 
488 static void __init request_crashkernel(struct resource *res)
489 {
490 	int ret;
491 
492 	if (crashk_res.start == crashk_res.end)
493 		return;
494 
495 	ret = request_resource(res, &crashk_res);
496 	if (!ret)
497 		pr_info("Reserving %ldMB of memory at %ldMB for crashkernel\n",
498 			(unsigned long)(resource_size(&crashk_res) >> 20),
499 			(unsigned long)(crashk_res.start  >> 20));
500 }
501 #else /* !defined(CONFIG_KEXEC)		*/
502 static void __init mips_parse_crashkernel(void)
503 {
504 }
505 
506 static void __init request_crashkernel(struct resource *res)
507 {
508 }
509 #endif /* !defined(CONFIG_KEXEC)  */
510 
511 static void __init check_kernel_sections_mem(void)
512 {
513 	phys_addr_t start = __pa_symbol(&_text);
514 	phys_addr_t size = __pa_symbol(&_end) - start;
515 
516 	if (!memblock_is_region_memory(start, size)) {
517 		pr_info("Kernel sections are not in the memory maps\n");
518 		memblock_add(start, size);
519 	}
520 }
521 
522 static void __init bootcmdline_append(const char *s, size_t max)
523 {
524 	if (!s[0] || !max)
525 		return;
526 
527 	if (boot_command_line[0])
528 		strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
529 
530 	strlcat(boot_command_line, s, max);
531 }
532 
533 #ifdef CONFIG_OF_EARLY_FLATTREE
534 
535 static int __init bootcmdline_scan_chosen(unsigned long node, const char *uname,
536 					  int depth, void *data)
537 {
538 	bool *dt_bootargs = data;
539 	const char *p;
540 	int l;
541 
542 	if (depth != 1 || !data ||
543 	    (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
544 		return 0;
545 
546 	p = of_get_flat_dt_prop(node, "bootargs", &l);
547 	if (p != NULL && l > 0) {
548 		bootcmdline_append(p, min(l, COMMAND_LINE_SIZE));
549 		*dt_bootargs = true;
550 	}
551 
552 	return 1;
553 }
554 
555 #endif /* CONFIG_OF_EARLY_FLATTREE */
556 
557 static void __init bootcmdline_init(void)
558 {
559 	bool dt_bootargs = false;
560 
561 	/*
562 	 * If CMDLINE_OVERRIDE is enabled then initializing the command line is
563 	 * trivial - we simply use the built-in command line unconditionally &
564 	 * unmodified.
565 	 */
566 	if (IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
567 		strscpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
568 		return;
569 	}
570 
571 	/*
572 	 * If the user specified a built-in command line &
573 	 * MIPS_CMDLINE_BUILTIN_EXTEND, then the built-in command line is
574 	 * prepended to arguments from the bootloader or DT so we'll copy them
575 	 * to the start of boot_command_line here. Otherwise, empty
576 	 * boot_command_line to undo anything early_init_dt_scan_chosen() did.
577 	 */
578 	if (IS_ENABLED(CONFIG_MIPS_CMDLINE_BUILTIN_EXTEND))
579 		strscpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
580 	else
581 		boot_command_line[0] = 0;
582 
583 #ifdef CONFIG_OF_EARLY_FLATTREE
584 	/*
585 	 * If we're configured to take boot arguments from DT, look for those
586 	 * now.
587 	 */
588 	if (IS_ENABLED(CONFIG_MIPS_CMDLINE_FROM_DTB) ||
589 	    IS_ENABLED(CONFIG_MIPS_CMDLINE_DTB_EXTEND))
590 		of_scan_flat_dt(bootcmdline_scan_chosen, &dt_bootargs);
591 #endif
592 
593 	/*
594 	 * If we didn't get any arguments from DT (regardless of whether that's
595 	 * because we weren't configured to look for them, or because we looked
596 	 * & found none) then we'll take arguments from the bootloader.
597 	 * plat_mem_setup() should have filled arcs_cmdline with arguments from
598 	 * the bootloader.
599 	 */
600 	if (IS_ENABLED(CONFIG_MIPS_CMDLINE_DTB_EXTEND) || !dt_bootargs)
601 		bootcmdline_append(arcs_cmdline, COMMAND_LINE_SIZE);
602 
603 	/*
604 	 * If the user specified a built-in command line & we didn't already
605 	 * prepend it, we append it to boot_command_line here.
606 	 */
607 	if (IS_ENABLED(CONFIG_CMDLINE_BOOL) &&
608 	    !IS_ENABLED(CONFIG_MIPS_CMDLINE_BUILTIN_EXTEND))
609 		bootcmdline_append(builtin_cmdline, COMMAND_LINE_SIZE);
610 }
611 
612 /*
613  * arch_mem_init - initialize memory management subsystem
614  *
615  *  o plat_mem_setup() detects the memory configuration and will record detected
616  *    memory areas using memblock_add.
617  *
618  * At this stage the memory configuration of the system is known to the
619  * kernel but generic memory management system is still entirely uninitialized.
620  *
621  *  o bootmem_init()
622  *  o sparse_init()
623  *  o paging_init()
624  *  o dma_contiguous_reserve()
625  *
626  * At this stage the bootmem allocator is ready to use.
627  *
628  * NOTE: historically plat_mem_setup did the entire platform initialization.
629  *	 This was rather impractical because it meant plat_mem_setup had to
630  * get away without any kind of memory allocator.  To keep old code from
631  * breaking plat_setup was just renamed to plat_mem_setup and a second platform
632  * initialization hook for anything else was introduced.
633  */
634 static void __init arch_mem_init(char **cmdline_p)
635 {
636 	/* call board setup routine */
637 	plat_mem_setup();
638 	memblock_set_bottom_up(true);
639 
640 	bootcmdline_init();
641 	strscpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
642 	*cmdline_p = command_line;
643 
644 	parse_early_param();
645 
646 	if (usermem)
647 		pr_info("User-defined physical RAM map overwrite\n");
648 
649 	check_kernel_sections_mem();
650 
651 	early_init_fdt_reserve_self();
652 	early_init_fdt_scan_reserved_mem();
653 
654 #ifndef CONFIG_NUMA
655 	memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
656 #endif
657 	bootmem_init();
658 
659 	/*
660 	 * Prevent memblock from allocating high memory.
661 	 * This cannot be done before max_low_pfn is detected, so up
662 	 * to this point is possible to only reserve physical memory
663 	 * with memblock_reserve; memblock_alloc* can be used
664 	 * only after this point
665 	 */
666 	memblock_set_current_limit(PFN_PHYS(max_low_pfn));
667 
668 	mips_reserve_vmcore();
669 
670 	mips_parse_crashkernel();
671 	device_tree_init();
672 
673 	/*
674 	 * In order to reduce the possibility of kernel panic when failed to
675 	 * get IO TLB memory under CONFIG_SWIOTLB, it is better to allocate
676 	 * low memory as small as possible before plat_swiotlb_setup(), so
677 	 * make sparse_init() using top-down allocation.
678 	 */
679 	memblock_set_bottom_up(false);
680 	sparse_init();
681 	memblock_set_bottom_up(true);
682 
683 	plat_swiotlb_setup();
684 
685 	dma_contiguous_reserve(PFN_PHYS(max_low_pfn));
686 
687 	/* Reserve for hibernation. */
688 	memblock_reserve(__pa_symbol(&__nosave_begin),
689 		__pa_symbol(&__nosave_end) - __pa_symbol(&__nosave_begin));
690 
691 	early_memtest(PFN_PHYS(ARCH_PFN_OFFSET), PFN_PHYS(max_low_pfn));
692 }
693 
694 static void __init resource_init(void)
695 {
696 	phys_addr_t start, end;
697 	u64 i;
698 
699 	if (UNCAC_BASE != IO_BASE)
700 		return;
701 
702 	code_resource.start = __pa_symbol(&_text);
703 	code_resource.end = __pa_symbol(&_etext) - 1;
704 	data_resource.start = __pa_symbol(&_etext);
705 	data_resource.end = __pa_symbol(&_edata) - 1;
706 	bss_resource.start = __pa_symbol(&__bss_start);
707 	bss_resource.end = __pa_symbol(&__bss_stop) - 1;
708 
709 	for_each_mem_range(i, &start, &end) {
710 		struct resource *res;
711 
712 		res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);
713 		if (!res)
714 			panic("%s: Failed to allocate %zu bytes\n", __func__,
715 			      sizeof(struct resource));
716 
717 		res->start = start;
718 		/*
719 		 * In memblock, end points to the first byte after the
720 		 * range while in resourses, end points to the last byte in
721 		 * the range.
722 		 */
723 		res->end = end - 1;
724 		res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
725 		res->name = "System RAM";
726 
727 		request_resource(&iomem_resource, res);
728 
729 		/*
730 		 *  We don't know which RAM region contains kernel data,
731 		 *  so we try it repeatedly and let the resource manager
732 		 *  test it.
733 		 */
734 		request_resource(res, &code_resource);
735 		request_resource(res, &data_resource);
736 		request_resource(res, &bss_resource);
737 		request_crashkernel(res);
738 	}
739 }
740 
741 #ifdef CONFIG_SMP
742 static void __init prefill_possible_map(void)
743 {
744 	int i, possible = num_possible_cpus();
745 
746 	if (possible > nr_cpu_ids)
747 		possible = nr_cpu_ids;
748 
749 	for (i = 0; i < possible; i++)
750 		set_cpu_possible(i, true);
751 	for (; i < NR_CPUS; i++)
752 		set_cpu_possible(i, false);
753 
754 	set_nr_cpu_ids(possible);
755 }
756 #else
757 static inline void prefill_possible_map(void) {}
758 #endif
759 
760 static void __init setup_rng_seed(void)
761 {
762 	char *rng_seed_hex = fw_getenv("rngseed");
763 	u8 rng_seed[512];
764 	size_t len;
765 
766 	if (!rng_seed_hex)
767 		return;
768 
769 	len = min(sizeof(rng_seed), strlen(rng_seed_hex) / 2);
770 	if (hex2bin(rng_seed, rng_seed_hex, len))
771 		return;
772 
773 	add_bootloader_randomness(rng_seed, len);
774 	memzero_explicit(rng_seed, len);
775 	memzero_explicit(rng_seed_hex, len * 2);
776 }
777 
778 void __init setup_arch(char **cmdline_p)
779 {
780 	cpu_probe();
781 	mips_cm_probe();
782 	prom_init();
783 
784 	setup_early_fdc_console();
785 #ifdef CONFIG_EARLY_PRINTK
786 	setup_early_printk();
787 #endif
788 	cpu_report();
789 	if (IS_ENABLED(CONFIG_CPU_R4X00_BUGS64))
790 		check_bugs64_early();
791 
792 #if defined(CONFIG_VT)
793 #if defined(CONFIG_VGA_CONSOLE)
794 	conswitchp = &vga_con;
795 #endif
796 #endif
797 
798 	arch_mem_init(cmdline_p);
799 	dmi_setup();
800 
801 	resource_init();
802 	plat_smp_setup();
803 	prefill_possible_map();
804 
805 	cpu_cache_init();
806 	paging_init();
807 
808 	memblock_dump_all();
809 
810 	setup_rng_seed();
811 }
812 
813 unsigned long kernelsp[NR_CPUS];
814 unsigned long fw_arg0, fw_arg1, fw_arg2, fw_arg3;
815 
816 #ifdef CONFIG_DEBUG_FS
817 struct dentry *mips_debugfs_dir;
818 static int __init debugfs_mips(void)
819 {
820 	mips_debugfs_dir = debugfs_create_dir("mips", NULL);
821 	return 0;
822 }
823 arch_initcall(debugfs_mips);
824 #endif
825 
826 #ifdef CONFIG_DMA_NONCOHERENT
827 static int __init setcoherentio(char *str)
828 {
829 	dma_default_coherent = true;
830 	pr_info("Hardware DMA cache coherency (command line)\n");
831 	return 0;
832 }
833 early_param("coherentio", setcoherentio);
834 
835 static int __init setnocoherentio(char *str)
836 {
837 	dma_default_coherent = false;
838 	pr_info("Software DMA cache coherency (command line)\n");
839 	return 0;
840 }
841 early_param("nocoherentio", setnocoherentio);
842 #endif
843