xref: /openbmc/linux/arch/mips/kernel/setup.c (revision 0e17c50f)
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-contiguous.h>
28 #include <linux/decompress/generic.h>
29 #include <linux/of_fdt.h>
30 #include <linux/of_reserved_mem.h>
31 
32 #include <asm/addrspace.h>
33 #include <asm/bootinfo.h>
34 #include <asm/bugs.h>
35 #include <asm/cache.h>
36 #include <asm/cdmm.h>
37 #include <asm/cpu.h>
38 #include <asm/debug.h>
39 #include <asm/dma-coherence.h>
40 #include <asm/sections.h>
41 #include <asm/setup.h>
42 #include <asm/smp-ops.h>
43 #include <asm/prom.h>
44 
45 #ifdef CONFIG_MIPS_ELF_APPENDED_DTB
46 const char __section(.appended_dtb) __appended_dtb[0x100000];
47 #endif /* CONFIG_MIPS_ELF_APPENDED_DTB */
48 
49 struct cpuinfo_mips cpu_data[NR_CPUS] __read_mostly;
50 
51 EXPORT_SYMBOL(cpu_data);
52 
53 #ifdef CONFIG_VT
54 struct screen_info screen_info;
55 #endif
56 
57 /*
58  * Setup information
59  *
60  * These are initialized so they are in the .data section
61  */
62 unsigned long mips_machtype __read_mostly = MACH_UNKNOWN;
63 
64 EXPORT_SYMBOL(mips_machtype);
65 
66 static char __initdata command_line[COMMAND_LINE_SIZE];
67 char __initdata arcs_cmdline[COMMAND_LINE_SIZE];
68 
69 #ifdef CONFIG_CMDLINE_BOOL
70 static const char builtin_cmdline[] __initconst = CONFIG_CMDLINE;
71 #else
72 static const char builtin_cmdline[] __initconst = "";
73 #endif
74 
75 /*
76  * mips_io_port_base is the begin of the address space to which x86 style
77  * I/O ports are mapped.
78  */
79 unsigned long mips_io_port_base = -1;
80 EXPORT_SYMBOL(mips_io_port_base);
81 
82 static struct resource code_resource = { .name = "Kernel code", };
83 static struct resource data_resource = { .name = "Kernel data", };
84 static struct resource bss_resource = { .name = "Kernel bss", };
85 
86 static void *detect_magic __initdata = detect_memory_region;
87 
88 #ifdef CONFIG_MIPS_AUTO_PFN_OFFSET
89 unsigned long ARCH_PFN_OFFSET;
90 EXPORT_SYMBOL(ARCH_PFN_OFFSET);
91 #endif
92 
93 void __init add_memory_region(phys_addr_t start, phys_addr_t size, long type)
94 {
95 	/*
96 	 * Note: This function only exists for historical reason,
97 	 * new code should use memblock_add or memblock_add_node instead.
98 	 */
99 
100 	/*
101 	 * If the region reaches the top of the physical address space, adjust
102 	 * the size slightly so that (start + size) doesn't overflow
103 	 */
104 	if (start + size - 1 == PHYS_ADDR_MAX)
105 		--size;
106 
107 	/* Sanity check */
108 	if (start + size < start) {
109 		pr_warn("Trying to add an invalid memory region, skipped\n");
110 		return;
111 	}
112 
113 	if (start < PHYS_OFFSET)
114 		return;
115 
116 	memblock_add(start, size);
117 	/* Reserve any memory except the ordinary RAM ranges. */
118 	switch (type) {
119 	case BOOT_MEM_RAM:
120 		break;
121 
122 	case BOOT_MEM_NOMAP: /* Discard the range from the system. */
123 		memblock_remove(start, size);
124 		break;
125 
126 	default: /* Reserve the rest of the memory types at boot time */
127 		memblock_reserve(start, size);
128 		break;
129 	}
130 }
131 
132 void __init detect_memory_region(phys_addr_t start, phys_addr_t sz_min, phys_addr_t sz_max)
133 {
134 	void *dm = &detect_magic;
135 	phys_addr_t size;
136 
137 	for (size = sz_min; size < sz_max; size <<= 1) {
138 		if (!memcmp(dm, dm + size, sizeof(detect_magic)))
139 			break;
140 	}
141 
142 	pr_debug("Memory: %lluMB of RAM detected at 0x%llx (min: %lluMB, max: %lluMB)\n",
143 		((unsigned long long) size) / SZ_1M,
144 		(unsigned long long) start,
145 		((unsigned long long) sz_min) / SZ_1M,
146 		((unsigned long long) sz_max) / SZ_1M);
147 
148 	add_memory_region(start, size, BOOT_MEM_RAM);
149 }
150 
151 /*
152  * Manage initrd
153  */
154 #ifdef CONFIG_BLK_DEV_INITRD
155 
156 static int __init rd_start_early(char *p)
157 {
158 	unsigned long start = memparse(p, &p);
159 
160 #ifdef CONFIG_64BIT
161 	/* Guess if the sign extension was forgotten by bootloader */
162 	if (start < XKPHYS)
163 		start = (int)start;
164 #endif
165 	initrd_start = start;
166 	initrd_end += start;
167 	return 0;
168 }
169 early_param("rd_start", rd_start_early);
170 
171 static int __init rd_size_early(char *p)
172 {
173 	initrd_end += memparse(p, &p);
174 	return 0;
175 }
176 early_param("rd_size", rd_size_early);
177 
178 /* it returns the next free pfn after initrd */
179 static unsigned long __init init_initrd(void)
180 {
181 	unsigned long end;
182 
183 	/*
184 	 * Board specific code or command line parser should have
185 	 * already set up initrd_start and initrd_end. In these cases
186 	 * perfom sanity checks and use them if all looks good.
187 	 */
188 	if (!initrd_start || initrd_end <= initrd_start)
189 		goto disable;
190 
191 	if (initrd_start & ~PAGE_MASK) {
192 		pr_err("initrd start must be page aligned\n");
193 		goto disable;
194 	}
195 	if (initrd_start < PAGE_OFFSET) {
196 		pr_err("initrd start < PAGE_OFFSET\n");
197 		goto disable;
198 	}
199 
200 	/*
201 	 * Sanitize initrd addresses. For example firmware
202 	 * can't guess if they need to pass them through
203 	 * 64-bits values if the kernel has been built in pure
204 	 * 32-bit. We need also to switch from KSEG0 to XKPHYS
205 	 * addresses now, so the code can now safely use __pa().
206 	 */
207 	end = __pa(initrd_end);
208 	initrd_end = (unsigned long)__va(end);
209 	initrd_start = (unsigned long)__va(__pa(initrd_start));
210 
211 	ROOT_DEV = Root_RAM0;
212 	return PFN_UP(end);
213 disable:
214 	initrd_start = 0;
215 	initrd_end = 0;
216 	return 0;
217 }
218 
219 /* In some conditions (e.g. big endian bootloader with a little endian
220    kernel), the initrd might appear byte swapped.  Try to detect this and
221    byte swap it if needed.  */
222 static void __init maybe_bswap_initrd(void)
223 {
224 #if defined(CONFIG_CPU_CAVIUM_OCTEON)
225 	u64 buf;
226 
227 	/* Check for CPIO signature */
228 	if (!memcmp((void *)initrd_start, "070701", 6))
229 		return;
230 
231 	/* Check for compressed initrd */
232 	if (decompress_method((unsigned char *)initrd_start, 8, NULL))
233 		return;
234 
235 	/* Try again with a byte swapped header */
236 	buf = swab64p((u64 *)initrd_start);
237 	if (!memcmp(&buf, "070701", 6) ||
238 	    decompress_method((unsigned char *)(&buf), 8, NULL)) {
239 		unsigned long i;
240 
241 		pr_info("Byteswapped initrd detected\n");
242 		for (i = initrd_start; i < ALIGN(initrd_end, 8); i += 8)
243 			swab64s((u64 *)i);
244 	}
245 #endif
246 }
247 
248 static void __init finalize_initrd(void)
249 {
250 	unsigned long size = initrd_end - initrd_start;
251 
252 	if (size == 0) {
253 		printk(KERN_INFO "Initrd not found or empty");
254 		goto disable;
255 	}
256 	if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
257 		printk(KERN_ERR "Initrd extends beyond end of memory");
258 		goto disable;
259 	}
260 
261 	maybe_bswap_initrd();
262 
263 	memblock_reserve(__pa(initrd_start), size);
264 	initrd_below_start_ok = 1;
265 
266 	pr_info("Initial ramdisk at: 0x%lx (%lu bytes)\n",
267 		initrd_start, size);
268 	return;
269 disable:
270 	printk(KERN_CONT " - disabling initrd\n");
271 	initrd_start = 0;
272 	initrd_end = 0;
273 }
274 
275 #else  /* !CONFIG_BLK_DEV_INITRD */
276 
277 static unsigned long __init init_initrd(void)
278 {
279 	return 0;
280 }
281 
282 #define finalize_initrd()	do {} while (0)
283 
284 #endif
285 
286 /*
287  * Initialize the bootmem allocator. It also setup initrd related data
288  * if needed.
289  */
290 #if defined(CONFIG_SGI_IP27) || (defined(CONFIG_CPU_LOONGSON64) && defined(CONFIG_NUMA))
291 
292 static void __init bootmem_init(void)
293 {
294 	init_initrd();
295 	finalize_initrd();
296 }
297 
298 #else  /* !CONFIG_SGI_IP27 */
299 
300 static void __init bootmem_init(void)
301 {
302 	struct memblock_region *mem;
303 	phys_addr_t ramstart, ramend;
304 
305 	ramstart = memblock_start_of_DRAM();
306 	ramend = memblock_end_of_DRAM();
307 
308 	/*
309 	 * Sanity check any INITRD first. We don't take it into account
310 	 * for bootmem setup initially, rely on the end-of-kernel-code
311 	 * as our memory range starting point. Once bootmem is inited we
312 	 * will reserve the area used for the initrd.
313 	 */
314 	init_initrd();
315 
316 	/* Reserve memory occupied by kernel. */
317 	memblock_reserve(__pa_symbol(&_text),
318 			__pa_symbol(&_end) - __pa_symbol(&_text));
319 
320 	/* max_low_pfn is not a number of pages but the end pfn of low mem */
321 
322 #ifdef CONFIG_MIPS_AUTO_PFN_OFFSET
323 	ARCH_PFN_OFFSET = PFN_UP(ramstart);
324 #else
325 	/*
326 	 * Reserve any memory between the start of RAM and PHYS_OFFSET
327 	 */
328 	if (ramstart > PHYS_OFFSET)
329 		memblock_reserve(PHYS_OFFSET, ramstart - PHYS_OFFSET);
330 
331 	if (PFN_UP(ramstart) > ARCH_PFN_OFFSET) {
332 		pr_info("Wasting %lu bytes for tracking %lu unused pages\n",
333 			(unsigned long)((PFN_UP(ramstart) - ARCH_PFN_OFFSET) * sizeof(struct page)),
334 			(unsigned long)(PFN_UP(ramstart) - ARCH_PFN_OFFSET));
335 	}
336 #endif
337 
338 	min_low_pfn = ARCH_PFN_OFFSET;
339 	max_pfn = PFN_DOWN(ramend);
340 	for_each_memblock(memory, mem) {
341 		unsigned long start = memblock_region_memory_base_pfn(mem);
342 		unsigned long end = memblock_region_memory_end_pfn(mem);
343 
344 		/*
345 		 * Skip highmem here so we get an accurate max_low_pfn if low
346 		 * memory stops short of high memory.
347 		 * If the region overlaps HIGHMEM_START, end is clipped so
348 		 * max_pfn excludes the highmem portion.
349 		 */
350 		if (memblock_is_nomap(mem))
351 			continue;
352 		if (start >= PFN_DOWN(HIGHMEM_START))
353 			continue;
354 		if (end > PFN_DOWN(HIGHMEM_START))
355 			end = PFN_DOWN(HIGHMEM_START);
356 		if (end > max_low_pfn)
357 			max_low_pfn = end;
358 	}
359 
360 	if (min_low_pfn >= max_low_pfn)
361 		panic("Incorrect memory mapping !!!");
362 
363 	if (max_pfn > PFN_DOWN(HIGHMEM_START)) {
364 #ifdef CONFIG_HIGHMEM
365 		highstart_pfn = PFN_DOWN(HIGHMEM_START);
366 		highend_pfn = max_pfn;
367 #else
368 		max_low_pfn = PFN_DOWN(HIGHMEM_START);
369 		max_pfn = max_low_pfn;
370 #endif
371 	}
372 
373 
374 	/*
375 	 * In any case the added to the memblock memory regions
376 	 * (highmem/lowmem, available/reserved, etc) are considered
377 	 * as present, so inform sparsemem about them.
378 	 */
379 	memblocks_present();
380 
381 	/*
382 	 * Reserve initrd memory if needed.
383 	 */
384 	finalize_initrd();
385 }
386 
387 #endif	/* CONFIG_SGI_IP27 */
388 
389 static int usermem __initdata;
390 
391 static int __init early_parse_mem(char *p)
392 {
393 	phys_addr_t start, size;
394 
395 	/*
396 	 * If a user specifies memory size, we
397 	 * blow away any automatically generated
398 	 * size.
399 	 */
400 	if (usermem == 0) {
401 		usermem = 1;
402 		memblock_remove(memblock_start_of_DRAM(),
403 			memblock_end_of_DRAM() - memblock_start_of_DRAM());
404 	}
405 	start = 0;
406 	size = memparse(p, &p);
407 	if (*p == '@')
408 		start = memparse(p + 1, &p);
409 
410 	add_memory_region(start, size, BOOT_MEM_RAM);
411 
412 	return 0;
413 }
414 early_param("mem", early_parse_mem);
415 
416 static int __init early_parse_memmap(char *p)
417 {
418 	char *oldp;
419 	u64 start_at, mem_size;
420 
421 	if (!p)
422 		return -EINVAL;
423 
424 	if (!strncmp(p, "exactmap", 8)) {
425 		pr_err("\"memmap=exactmap\" invalid on MIPS\n");
426 		return 0;
427 	}
428 
429 	oldp = p;
430 	mem_size = memparse(p, &p);
431 	if (p == oldp)
432 		return -EINVAL;
433 
434 	if (*p == '@') {
435 		start_at = memparse(p+1, &p);
436 		add_memory_region(start_at, mem_size, BOOT_MEM_RAM);
437 	} else if (*p == '#') {
438 		pr_err("\"memmap=nn#ss\" (force ACPI data) invalid on MIPS\n");
439 		return -EINVAL;
440 	} else if (*p == '$') {
441 		start_at = memparse(p+1, &p);
442 		add_memory_region(start_at, mem_size, BOOT_MEM_RESERVED);
443 	} else {
444 		pr_err("\"memmap\" invalid format!\n");
445 		return -EINVAL;
446 	}
447 
448 	if (*p == '\0') {
449 		usermem = 1;
450 		return 0;
451 	} else
452 		return -EINVAL;
453 }
454 early_param("memmap", early_parse_memmap);
455 
456 #ifdef CONFIG_PROC_VMCORE
457 unsigned long setup_elfcorehdr, setup_elfcorehdr_size;
458 static int __init early_parse_elfcorehdr(char *p)
459 {
460 	struct memblock_region *mem;
461 
462 	setup_elfcorehdr = memparse(p, &p);
463 
464 	 for_each_memblock(memory, mem) {
465 		unsigned long start = mem->base;
466 		unsigned long end = start + mem->size;
467 		if (setup_elfcorehdr >= start && setup_elfcorehdr < end) {
468 			/*
469 			 * Reserve from the elf core header to the end of
470 			 * the memory segment, that should all be kdump
471 			 * reserved memory.
472 			 */
473 			setup_elfcorehdr_size = end - setup_elfcorehdr;
474 			break;
475 		}
476 	}
477 	/*
478 	 * If we don't find it in the memory map, then we shouldn't
479 	 * have to worry about it, as the new kernel won't use it.
480 	 */
481 	return 0;
482 }
483 early_param("elfcorehdr", early_parse_elfcorehdr);
484 #endif
485 
486 #ifdef CONFIG_KEXEC
487 static void __init mips_parse_crashkernel(void)
488 {
489 	unsigned long long total_mem;
490 	unsigned long long crash_size, crash_base;
491 	int ret;
492 
493 	total_mem = memblock_phys_mem_size();
494 	ret = parse_crashkernel(boot_command_line, total_mem,
495 				&crash_size, &crash_base);
496 	if (ret != 0 || crash_size <= 0)
497 		return;
498 
499 	if (!memblock_find_in_range(crash_base, crash_base + crash_size, crash_size, 0)) {
500 		pr_warn("Invalid memory region reserved for crash kernel\n");
501 		return;
502 	}
503 
504 	crashk_res.start = crash_base;
505 	crashk_res.end	 = crash_base + crash_size - 1;
506 }
507 
508 static void __init request_crashkernel(struct resource *res)
509 {
510 	int ret;
511 
512 	if (crashk_res.start == crashk_res.end)
513 		return;
514 
515 	ret = request_resource(res, &crashk_res);
516 	if (!ret)
517 		pr_info("Reserving %ldMB of memory at %ldMB for crashkernel\n",
518 			(unsigned long)(resource_size(&crashk_res) >> 20),
519 			(unsigned long)(crashk_res.start  >> 20));
520 }
521 #else /* !defined(CONFIG_KEXEC)		*/
522 static void __init mips_parse_crashkernel(void)
523 {
524 }
525 
526 static void __init request_crashkernel(struct resource *res)
527 {
528 }
529 #endif /* !defined(CONFIG_KEXEC)  */
530 
531 static void __init check_kernel_sections_mem(void)
532 {
533 	phys_addr_t start = PFN_PHYS(PFN_DOWN(__pa_symbol(&_text)));
534 	phys_addr_t size = PFN_PHYS(PFN_UP(__pa_symbol(&_end))) - start;
535 
536 	if (!memblock_is_region_memory(start, size)) {
537 		pr_info("Kernel sections are not in the memory maps\n");
538 		memblock_add(start, size);
539 	}
540 }
541 
542 static void __init bootcmdline_append(const char *s, size_t max)
543 {
544 	if (!s[0] || !max)
545 		return;
546 
547 	if (boot_command_line[0])
548 		strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
549 
550 	strlcat(boot_command_line, s, max);
551 }
552 
553 #ifdef CONFIG_OF_EARLY_FLATTREE
554 
555 static int __init bootcmdline_scan_chosen(unsigned long node, const char *uname,
556 					  int depth, void *data)
557 {
558 	bool *dt_bootargs = data;
559 	const char *p;
560 	int l;
561 
562 	if (depth != 1 || !data ||
563 	    (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
564 		return 0;
565 
566 	p = of_get_flat_dt_prop(node, "bootargs", &l);
567 	if (p != NULL && l > 0) {
568 		bootcmdline_append(p, min(l, COMMAND_LINE_SIZE));
569 		*dt_bootargs = true;
570 	}
571 
572 	return 1;
573 }
574 
575 #endif /* CONFIG_OF_EARLY_FLATTREE */
576 
577 static void __init bootcmdline_init(char **cmdline_p)
578 {
579 	bool dt_bootargs = false;
580 
581 	/*
582 	 * If CMDLINE_OVERRIDE is enabled then initializing the command line is
583 	 * trivial - we simply use the built-in command line unconditionally &
584 	 * unmodified.
585 	 */
586 	if (IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
587 		strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
588 		return;
589 	}
590 
591 	/*
592 	 * If the user specified a built-in command line &
593 	 * MIPS_CMDLINE_BUILTIN_EXTEND, then the built-in command line is
594 	 * prepended to arguments from the bootloader or DT so we'll copy them
595 	 * to the start of boot_command_line here. Otherwise, empty
596 	 * boot_command_line to undo anything early_init_dt_scan_chosen() did.
597 	 */
598 	if (IS_ENABLED(CONFIG_MIPS_CMDLINE_BUILTIN_EXTEND))
599 		strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
600 	else
601 		boot_command_line[0] = 0;
602 
603 #ifdef CONFIG_OF_EARLY_FLATTREE
604 	/*
605 	 * If we're configured to take boot arguments from DT, look for those
606 	 * now.
607 	 */
608 	if (IS_ENABLED(CONFIG_MIPS_CMDLINE_FROM_DTB))
609 		of_scan_flat_dt(bootcmdline_scan_chosen, &dt_bootargs);
610 #endif
611 
612 	/*
613 	 * If we didn't get any arguments from DT (regardless of whether that's
614 	 * because we weren't configured to look for them, or because we looked
615 	 * & found none) then we'll take arguments from the bootloader.
616 	 * plat_mem_setup() should have filled arcs_cmdline with arguments from
617 	 * the bootloader.
618 	 */
619 	if (IS_ENABLED(CONFIG_MIPS_CMDLINE_DTB_EXTEND) || !dt_bootargs)
620 		bootcmdline_append(arcs_cmdline, COMMAND_LINE_SIZE);
621 
622 	/*
623 	 * If the user specified a built-in command line & we didn't already
624 	 * prepend it, we append it to boot_command_line here.
625 	 */
626 	if (IS_ENABLED(CONFIG_CMDLINE_BOOL) &&
627 	    !IS_ENABLED(CONFIG_MIPS_CMDLINE_BUILTIN_EXTEND))
628 		bootcmdline_append(builtin_cmdline, COMMAND_LINE_SIZE);
629 }
630 
631 /*
632  * arch_mem_init - initialize memory management subsystem
633  *
634  *  o plat_mem_setup() detects the memory configuration and will record detected
635  *    memory areas using add_memory_region.
636  *
637  * At this stage the memory configuration of the system is known to the
638  * kernel but generic memory management system is still entirely uninitialized.
639  *
640  *  o bootmem_init()
641  *  o sparse_init()
642  *  o paging_init()
643  *  o dma_contiguous_reserve()
644  *
645  * At this stage the bootmem allocator is ready to use.
646  *
647  * NOTE: historically plat_mem_setup did the entire platform initialization.
648  *	 This was rather impractical because it meant plat_mem_setup had to
649  * get away without any kind of memory allocator.  To keep old code from
650  * breaking plat_setup was just renamed to plat_mem_setup and a second platform
651  * initialization hook for anything else was introduced.
652  */
653 static void __init arch_mem_init(char **cmdline_p)
654 {
655 	extern void plat_mem_setup(void);
656 
657 	/* call board setup routine */
658 	plat_mem_setup();
659 	memblock_set_bottom_up(true);
660 
661 	bootcmdline_init(cmdline_p);
662 	strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
663 	*cmdline_p = command_line;
664 
665 	parse_early_param();
666 
667 	if (usermem)
668 		pr_info("User-defined physical RAM map overwrite\n");
669 
670 	check_kernel_sections_mem();
671 
672 	early_init_fdt_reserve_self();
673 	early_init_fdt_scan_reserved_mem();
674 
675 #ifndef CONFIG_NUMA
676 	memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
677 #endif
678 	bootmem_init();
679 
680 	/*
681 	 * Prevent memblock from allocating high memory.
682 	 * This cannot be done before max_low_pfn is detected, so up
683 	 * to this point is possible to only reserve physical memory
684 	 * with memblock_reserve; memblock_alloc* can be used
685 	 * only after this point
686 	 */
687 	memblock_set_current_limit(PFN_PHYS(max_low_pfn));
688 
689 #ifdef CONFIG_PROC_VMCORE
690 	if (setup_elfcorehdr && setup_elfcorehdr_size) {
691 		printk(KERN_INFO "kdump reserved memory at %lx-%lx\n",
692 		       setup_elfcorehdr, setup_elfcorehdr_size);
693 		memblock_reserve(setup_elfcorehdr, setup_elfcorehdr_size);
694 	}
695 #endif
696 
697 	mips_parse_crashkernel();
698 #ifdef CONFIG_KEXEC
699 	if (crashk_res.start != crashk_res.end)
700 		memblock_reserve(crashk_res.start, resource_size(&crashk_res));
701 #endif
702 	device_tree_init();
703 	sparse_init();
704 	plat_swiotlb_setup();
705 
706 	dma_contiguous_reserve(PFN_PHYS(max_low_pfn));
707 
708 	/* Reserve for hibernation. */
709 	memblock_reserve(__pa_symbol(&__nosave_begin),
710 		__pa_symbol(&__nosave_end) - __pa_symbol(&__nosave_begin));
711 
712 	fdt_init_reserved_mem();
713 
714 	memblock_dump_all();
715 
716 	early_memtest(PFN_PHYS(ARCH_PFN_OFFSET), PFN_PHYS(max_low_pfn));
717 }
718 
719 static void __init resource_init(void)
720 {
721 	struct memblock_region *region;
722 
723 	if (UNCAC_BASE != IO_BASE)
724 		return;
725 
726 	code_resource.start = __pa_symbol(&_text);
727 	code_resource.end = __pa_symbol(&_etext) - 1;
728 	data_resource.start = __pa_symbol(&_etext);
729 	data_resource.end = __pa_symbol(&_edata) - 1;
730 	bss_resource.start = __pa_symbol(&__bss_start);
731 	bss_resource.end = __pa_symbol(&__bss_stop) - 1;
732 
733 	for_each_memblock(memory, region) {
734 		phys_addr_t start = PFN_PHYS(memblock_region_memory_base_pfn(region));
735 		phys_addr_t end = PFN_PHYS(memblock_region_memory_end_pfn(region)) - 1;
736 		struct resource *res;
737 
738 		res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);
739 		if (!res)
740 			panic("%s: Failed to allocate %zu bytes\n", __func__,
741 			      sizeof(struct resource));
742 
743 		res->start = start;
744 		res->end = end;
745 		res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
746 		res->name = "System RAM";
747 
748 		request_resource(&iomem_resource, res);
749 
750 		/*
751 		 *  We don't know which RAM region contains kernel data,
752 		 *  so we try it repeatedly and let the resource manager
753 		 *  test it.
754 		 */
755 		request_resource(res, &code_resource);
756 		request_resource(res, &data_resource);
757 		request_resource(res, &bss_resource);
758 		request_crashkernel(res);
759 	}
760 }
761 
762 #ifdef CONFIG_SMP
763 static void __init prefill_possible_map(void)
764 {
765 	int i, possible = num_possible_cpus();
766 
767 	if (possible > nr_cpu_ids)
768 		possible = nr_cpu_ids;
769 
770 	for (i = 0; i < possible; i++)
771 		set_cpu_possible(i, true);
772 	for (; i < NR_CPUS; i++)
773 		set_cpu_possible(i, false);
774 
775 	nr_cpu_ids = possible;
776 }
777 #else
778 static inline void prefill_possible_map(void) {}
779 #endif
780 
781 void __init setup_arch(char **cmdline_p)
782 {
783 	cpu_probe();
784 	mips_cm_probe();
785 	prom_init();
786 
787 	setup_early_fdc_console();
788 #ifdef CONFIG_EARLY_PRINTK
789 	setup_early_printk();
790 #endif
791 	cpu_report();
792 	check_bugs_early();
793 
794 #if defined(CONFIG_VT)
795 #if defined(CONFIG_VGA_CONSOLE)
796 	conswitchp = &vga_con;
797 #endif
798 #endif
799 
800 	arch_mem_init(cmdline_p);
801 
802 	resource_init();
803 	plat_smp_setup();
804 	prefill_possible_map();
805 
806 	cpu_cache_init();
807 	paging_init();
808 }
809 
810 unsigned long kernelsp[NR_CPUS];
811 unsigned long fw_arg0, fw_arg1, fw_arg2, fw_arg3;
812 
813 #ifdef CONFIG_USE_OF
814 unsigned long fw_passed_dtb;
815 #endif
816 
817 #ifdef CONFIG_DEBUG_FS
818 struct dentry *mips_debugfs_dir;
819 static int __init debugfs_mips(void)
820 {
821 	mips_debugfs_dir = debugfs_create_dir("mips", NULL);
822 	return 0;
823 }
824 arch_initcall(debugfs_mips);
825 #endif
826 
827 #ifdef CONFIG_DMA_MAYBE_COHERENT
828 /* User defined DMA coherency from command line. */
829 enum coherent_io_user_state coherentio = IO_COHERENCE_DEFAULT;
830 EXPORT_SYMBOL_GPL(coherentio);
831 int hw_coherentio = 0;	/* Actual hardware supported DMA coherency setting. */
832 
833 static int __init setcoherentio(char *str)
834 {
835 	coherentio = IO_COHERENCE_ENABLED;
836 	pr_info("Hardware DMA cache coherency (command line)\n");
837 	return 0;
838 }
839 early_param("coherentio", setcoherentio);
840 
841 static int __init setnocoherentio(char *str)
842 {
843 	coherentio = IO_COHERENCE_DISABLED;
844 	pr_info("Software DMA cache coherency (command line)\n");
845 	return 0;
846 }
847 early_param("nocoherentio", setnocoherentio);
848 #endif
849