xref: /openbmc/linux/arch/mips/kernel/setup.c (revision 82df5b73)
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 #include <linux/dmi.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/dma-coherence.h>
41 #include <asm/sections.h>
42 #include <asm/setup.h>
43 #include <asm/smp-ops.h>
44 #include <asm/prom.h>
45 
46 #ifdef CONFIG_MIPS_ELF_APPENDED_DTB
47 const char __section(.appended_dtb) __appended_dtb[0x100000];
48 #endif /* CONFIG_MIPS_ELF_APPENDED_DTB */
49 
50 struct cpuinfo_mips cpu_data[NR_CPUS] __read_mostly;
51 
52 EXPORT_SYMBOL(cpu_data);
53 
54 #ifdef CONFIG_VT
55 struct screen_info screen_info;
56 #endif
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 static void *detect_magic __initdata = detect_memory_region;
88 
89 #ifdef CONFIG_MIPS_AUTO_PFN_OFFSET
90 unsigned long ARCH_PFN_OFFSET;
91 EXPORT_SYMBOL(ARCH_PFN_OFFSET);
92 #endif
93 
94 void __init add_memory_region(phys_addr_t start, phys_addr_t size, long type)
95 {
96 	/*
97 	 * Note: This function only exists for historical reason,
98 	 * new code should use memblock_add or memblock_add_node instead.
99 	 */
100 
101 	/*
102 	 * If the region reaches the top of the physical address space, adjust
103 	 * the size slightly so that (start + size) doesn't overflow
104 	 */
105 	if (start + size - 1 == PHYS_ADDR_MAX)
106 		--size;
107 
108 	/* Sanity check */
109 	if (start + size < start) {
110 		pr_warn("Trying to add an invalid memory region, skipped\n");
111 		return;
112 	}
113 
114 	if (start < PHYS_OFFSET)
115 		return;
116 
117 	memblock_add(start, size);
118 	/* Reserve any memory except the ordinary RAM ranges. */
119 	switch (type) {
120 	case BOOT_MEM_RAM:
121 		break;
122 
123 	case BOOT_MEM_NOMAP: /* Discard the range from the system. */
124 		memblock_remove(start, size);
125 		break;
126 
127 	default: /* Reserve the rest of the memory types at boot time */
128 		memblock_reserve(start, size);
129 		break;
130 	}
131 }
132 
133 void __init detect_memory_region(phys_addr_t start, phys_addr_t sz_min, phys_addr_t sz_max)
134 {
135 	void *dm = &detect_magic;
136 	phys_addr_t size;
137 
138 	for (size = sz_min; size < sz_max; size <<= 1) {
139 		if (!memcmp(dm, dm + size, sizeof(detect_magic)))
140 			break;
141 	}
142 
143 	pr_debug("Memory: %lluMB of RAM detected at 0x%llx (min: %lluMB, max: %lluMB)\n",
144 		((unsigned long long) size) / SZ_1M,
145 		(unsigned long long) start,
146 		((unsigned long long) sz_min) / SZ_1M,
147 		((unsigned long long) sz_max) / SZ_1M);
148 
149 	add_memory_region(start, size, BOOT_MEM_RAM);
150 }
151 
152 /*
153  * Manage initrd
154  */
155 #ifdef CONFIG_BLK_DEV_INITRD
156 
157 static int __init rd_start_early(char *p)
158 {
159 	unsigned long start = memparse(p, &p);
160 
161 #ifdef CONFIG_64BIT
162 	/* Guess if the sign extension was forgotten by bootloader */
163 	if (start < XKPHYS)
164 		start = (int)start;
165 #endif
166 	initrd_start = start;
167 	initrd_end += start;
168 	return 0;
169 }
170 early_param("rd_start", rd_start_early);
171 
172 static int __init rd_size_early(char *p)
173 {
174 	initrd_end += memparse(p, &p);
175 	return 0;
176 }
177 early_param("rd_size", rd_size_early);
178 
179 /* it returns the next free pfn after initrd */
180 static unsigned long __init init_initrd(void)
181 {
182 	unsigned long end;
183 
184 	/*
185 	 * Board specific code or command line parser should have
186 	 * already set up initrd_start and initrd_end. In these cases
187 	 * perfom sanity checks and use them if all looks good.
188 	 */
189 	if (!initrd_start || initrd_end <= initrd_start)
190 		goto disable;
191 
192 	if (initrd_start & ~PAGE_MASK) {
193 		pr_err("initrd start must be page aligned\n");
194 		goto disable;
195 	}
196 	if (initrd_start < PAGE_OFFSET) {
197 		pr_err("initrd start < PAGE_OFFSET\n");
198 		goto disable;
199 	}
200 
201 	/*
202 	 * Sanitize initrd addresses. For example firmware
203 	 * can't guess if they need to pass them through
204 	 * 64-bits values if the kernel has been built in pure
205 	 * 32-bit. We need also to switch from KSEG0 to XKPHYS
206 	 * addresses now, so the code can now safely use __pa().
207 	 */
208 	end = __pa(initrd_end);
209 	initrd_end = (unsigned long)__va(end);
210 	initrd_start = (unsigned long)__va(__pa(initrd_start));
211 
212 	ROOT_DEV = Root_RAM0;
213 	return PFN_UP(end);
214 disable:
215 	initrd_start = 0;
216 	initrd_end = 0;
217 	return 0;
218 }
219 
220 /* In some conditions (e.g. big endian bootloader with a little endian
221    kernel), the initrd might appear byte swapped.  Try to detect this and
222    byte swap it if needed.  */
223 static void __init maybe_bswap_initrd(void)
224 {
225 #if defined(CONFIG_CPU_CAVIUM_OCTEON)
226 	u64 buf;
227 
228 	/* Check for CPIO signature */
229 	if (!memcmp((void *)initrd_start, "070701", 6))
230 		return;
231 
232 	/* Check for compressed initrd */
233 	if (decompress_method((unsigned char *)initrd_start, 8, NULL))
234 		return;
235 
236 	/* Try again with a byte swapped header */
237 	buf = swab64p((u64 *)initrd_start);
238 	if (!memcmp(&buf, "070701", 6) ||
239 	    decompress_method((unsigned char *)(&buf), 8, NULL)) {
240 		unsigned long i;
241 
242 		pr_info("Byteswapped initrd detected\n");
243 		for (i = initrd_start; i < ALIGN(initrd_end, 8); i += 8)
244 			swab64s((u64 *)i);
245 	}
246 #endif
247 }
248 
249 static void __init finalize_initrd(void)
250 {
251 	unsigned long size = initrd_end - initrd_start;
252 
253 	if (size == 0) {
254 		printk(KERN_INFO "Initrd not found or empty");
255 		goto disable;
256 	}
257 	if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
258 		printk(KERN_ERR "Initrd extends beyond end of memory");
259 		goto disable;
260 	}
261 
262 	maybe_bswap_initrd();
263 
264 	memblock_reserve(__pa(initrd_start), size);
265 	initrd_below_start_ok = 1;
266 
267 	pr_info("Initial ramdisk at: 0x%lx (%lu bytes)\n",
268 		initrd_start, size);
269 	return;
270 disable:
271 	printk(KERN_CONT " - disabling initrd\n");
272 	initrd_start = 0;
273 	initrd_end = 0;
274 }
275 
276 #else  /* !CONFIG_BLK_DEV_INITRD */
277 
278 static unsigned long __init init_initrd(void)
279 {
280 	return 0;
281 }
282 
283 #define finalize_initrd()	do {} while (0)
284 
285 #endif
286 
287 /*
288  * Initialize the bootmem allocator. It also setup initrd related data
289  * if needed.
290  */
291 #if defined(CONFIG_SGI_IP27) || (defined(CONFIG_CPU_LOONGSON64) && defined(CONFIG_NUMA))
292 
293 static void __init bootmem_init(void)
294 {
295 	init_initrd();
296 	finalize_initrd();
297 }
298 
299 #else  /* !CONFIG_SGI_IP27 */
300 
301 static void __init bootmem_init(void)
302 {
303 	struct memblock_region *mem;
304 	phys_addr_t ramstart, ramend;
305 
306 	ramstart = memblock_start_of_DRAM();
307 	ramend = memblock_end_of_DRAM();
308 
309 	/*
310 	 * Sanity check any INITRD first. We don't take it into account
311 	 * for bootmem setup initially, rely on the end-of-kernel-code
312 	 * as our memory range starting point. Once bootmem is inited we
313 	 * will reserve the area used for the initrd.
314 	 */
315 	init_initrd();
316 
317 	/* Reserve memory occupied by kernel. */
318 	memblock_reserve(__pa_symbol(&_text),
319 			__pa_symbol(&_end) - __pa_symbol(&_text));
320 
321 	/* max_low_pfn is not a number of pages but the end pfn of low mem */
322 
323 #ifdef CONFIG_MIPS_AUTO_PFN_OFFSET
324 	ARCH_PFN_OFFSET = PFN_UP(ramstart);
325 #else
326 	/*
327 	 * Reserve any memory between the start of RAM and PHYS_OFFSET
328 	 */
329 	if (ramstart > PHYS_OFFSET)
330 		memblock_reserve(PHYS_OFFSET, ramstart - PHYS_OFFSET);
331 
332 	if (PFN_UP(ramstart) > ARCH_PFN_OFFSET) {
333 		pr_info("Wasting %lu bytes for tracking %lu unused pages\n",
334 			(unsigned long)((PFN_UP(ramstart) - ARCH_PFN_OFFSET) * sizeof(struct page)),
335 			(unsigned long)(PFN_UP(ramstart) - ARCH_PFN_OFFSET));
336 	}
337 #endif
338 
339 	min_low_pfn = ARCH_PFN_OFFSET;
340 	max_pfn = PFN_DOWN(ramend);
341 	for_each_memblock(memory, mem) {
342 		unsigned long start = memblock_region_memory_base_pfn(mem);
343 		unsigned long end = memblock_region_memory_end_pfn(mem);
344 
345 		/*
346 		 * Skip highmem here so we get an accurate max_low_pfn if low
347 		 * memory stops short of high memory.
348 		 * If the region overlaps HIGHMEM_START, end is clipped so
349 		 * max_pfn excludes the highmem portion.
350 		 */
351 		if (memblock_is_nomap(mem))
352 			continue;
353 		if (start >= PFN_DOWN(HIGHMEM_START))
354 			continue;
355 		if (end > PFN_DOWN(HIGHMEM_START))
356 			end = PFN_DOWN(HIGHMEM_START);
357 		if (end > max_low_pfn)
358 			max_low_pfn = end;
359 	}
360 
361 	if (min_low_pfn >= max_low_pfn)
362 		panic("Incorrect memory mapping !!!");
363 
364 	if (max_pfn > PFN_DOWN(HIGHMEM_START)) {
365 #ifdef CONFIG_HIGHMEM
366 		highstart_pfn = PFN_DOWN(HIGHMEM_START);
367 		highend_pfn = max_pfn;
368 #else
369 		max_low_pfn = PFN_DOWN(HIGHMEM_START);
370 		max_pfn = max_low_pfn;
371 #endif
372 	}
373 
374 
375 	/*
376 	 * In any case the added to the memblock memory regions
377 	 * (highmem/lowmem, available/reserved, etc) are considered
378 	 * as present, so inform sparsemem about them.
379 	 */
380 	memblocks_present();
381 
382 	/*
383 	 * Reserve initrd memory if needed.
384 	 */
385 	finalize_initrd();
386 }
387 
388 #endif	/* CONFIG_SGI_IP27 */
389 
390 static int usermem __initdata;
391 
392 static int __init early_parse_mem(char *p)
393 {
394 	phys_addr_t start, size;
395 
396 	/*
397 	 * If a user specifies memory size, we
398 	 * blow away any automatically generated
399 	 * size.
400 	 */
401 	if (usermem == 0) {
402 		usermem = 1;
403 		memblock_remove(memblock_start_of_DRAM(),
404 			memblock_end_of_DRAM() - memblock_start_of_DRAM());
405 	}
406 	start = 0;
407 	size = memparse(p, &p);
408 	if (*p == '@')
409 		start = memparse(p + 1, &p);
410 
411 	add_memory_region(start, size, BOOT_MEM_RAM);
412 
413 	return 0;
414 }
415 early_param("mem", early_parse_mem);
416 
417 static int __init early_parse_memmap(char *p)
418 {
419 	char *oldp;
420 	u64 start_at, mem_size;
421 
422 	if (!p)
423 		return -EINVAL;
424 
425 	if (!strncmp(p, "exactmap", 8)) {
426 		pr_err("\"memmap=exactmap\" invalid on MIPS\n");
427 		return 0;
428 	}
429 
430 	oldp = p;
431 	mem_size = memparse(p, &p);
432 	if (p == oldp)
433 		return -EINVAL;
434 
435 	if (*p == '@') {
436 		start_at = memparse(p+1, &p);
437 		add_memory_region(start_at, mem_size, BOOT_MEM_RAM);
438 	} else if (*p == '#') {
439 		pr_err("\"memmap=nn#ss\" (force ACPI data) invalid on MIPS\n");
440 		return -EINVAL;
441 	} else if (*p == '$') {
442 		start_at = memparse(p+1, &p);
443 		add_memory_region(start_at, mem_size, BOOT_MEM_RESERVED);
444 	} else {
445 		pr_err("\"memmap\" invalid format!\n");
446 		return -EINVAL;
447 	}
448 
449 	if (*p == '\0') {
450 		usermem = 1;
451 		return 0;
452 	} else
453 		return -EINVAL;
454 }
455 early_param("memmap", early_parse_memmap);
456 
457 #ifdef CONFIG_PROC_VMCORE
458 unsigned long setup_elfcorehdr, setup_elfcorehdr_size;
459 static int __init early_parse_elfcorehdr(char *p)
460 {
461 	struct memblock_region *mem;
462 
463 	setup_elfcorehdr = memparse(p, &p);
464 
465 	 for_each_memblock(memory, mem) {
466 		unsigned long start = mem->base;
467 		unsigned long end = start + mem->size;
468 		if (setup_elfcorehdr >= start && setup_elfcorehdr < end) {
469 			/*
470 			 * Reserve from the elf core header to the end of
471 			 * the memory segment, that should all be kdump
472 			 * reserved memory.
473 			 */
474 			setup_elfcorehdr_size = end - setup_elfcorehdr;
475 			break;
476 		}
477 	}
478 	/*
479 	 * If we don't find it in the memory map, then we shouldn't
480 	 * have to worry about it, as the new kernel won't use it.
481 	 */
482 	return 0;
483 }
484 early_param("elfcorehdr", early_parse_elfcorehdr);
485 #endif
486 
487 #ifdef CONFIG_KEXEC
488 static void __init mips_parse_crashkernel(void)
489 {
490 	unsigned long long total_mem;
491 	unsigned long long crash_size, crash_base;
492 	int ret;
493 
494 	total_mem = memblock_phys_mem_size();
495 	ret = parse_crashkernel(boot_command_line, total_mem,
496 				&crash_size, &crash_base);
497 	if (ret != 0 || crash_size <= 0)
498 		return;
499 
500 	if (!memblock_find_in_range(crash_base, crash_base + crash_size, crash_size, 0)) {
501 		pr_warn("Invalid memory region reserved for crash kernel\n");
502 		return;
503 	}
504 
505 	crashk_res.start = crash_base;
506 	crashk_res.end	 = crash_base + crash_size - 1;
507 }
508 
509 static void __init request_crashkernel(struct resource *res)
510 {
511 	int ret;
512 
513 	if (crashk_res.start == crashk_res.end)
514 		return;
515 
516 	ret = request_resource(res, &crashk_res);
517 	if (!ret)
518 		pr_info("Reserving %ldMB of memory at %ldMB for crashkernel\n",
519 			(unsigned long)(resource_size(&crashk_res) >> 20),
520 			(unsigned long)(crashk_res.start  >> 20));
521 }
522 #else /* !defined(CONFIG_KEXEC)		*/
523 static void __init mips_parse_crashkernel(void)
524 {
525 }
526 
527 static void __init request_crashkernel(struct resource *res)
528 {
529 }
530 #endif /* !defined(CONFIG_KEXEC)  */
531 
532 static void __init check_kernel_sections_mem(void)
533 {
534 	phys_addr_t start = PFN_PHYS(PFN_DOWN(__pa_symbol(&_text)));
535 	phys_addr_t size = PFN_PHYS(PFN_UP(__pa_symbol(&_end))) - start;
536 
537 	if (!memblock_is_region_memory(start, size)) {
538 		pr_info("Kernel sections are not in the memory maps\n");
539 		memblock_add(start, size);
540 	}
541 }
542 
543 static void __init bootcmdline_append(const char *s, size_t max)
544 {
545 	if (!s[0] || !max)
546 		return;
547 
548 	if (boot_command_line[0])
549 		strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
550 
551 	strlcat(boot_command_line, s, max);
552 }
553 
554 #ifdef CONFIG_OF_EARLY_FLATTREE
555 
556 static int __init bootcmdline_scan_chosen(unsigned long node, const char *uname,
557 					  int depth, void *data)
558 {
559 	bool *dt_bootargs = data;
560 	const char *p;
561 	int l;
562 
563 	if (depth != 1 || !data ||
564 	    (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
565 		return 0;
566 
567 	p = of_get_flat_dt_prop(node, "bootargs", &l);
568 	if (p != NULL && l > 0) {
569 		bootcmdline_append(p, min(l, COMMAND_LINE_SIZE));
570 		*dt_bootargs = true;
571 	}
572 
573 	return 1;
574 }
575 
576 #endif /* CONFIG_OF_EARLY_FLATTREE */
577 
578 static void __init bootcmdline_init(void)
579 {
580 	bool dt_bootargs = false;
581 
582 	/*
583 	 * If CMDLINE_OVERRIDE is enabled then initializing the command line is
584 	 * trivial - we simply use the built-in command line unconditionally &
585 	 * unmodified.
586 	 */
587 	if (IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
588 		strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
589 		return;
590 	}
591 
592 	/*
593 	 * If the user specified a built-in command line &
594 	 * MIPS_CMDLINE_BUILTIN_EXTEND, then the built-in command line is
595 	 * prepended to arguments from the bootloader or DT so we'll copy them
596 	 * to the start of boot_command_line here. Otherwise, empty
597 	 * boot_command_line to undo anything early_init_dt_scan_chosen() did.
598 	 */
599 	if (IS_ENABLED(CONFIG_MIPS_CMDLINE_BUILTIN_EXTEND))
600 		strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
601 	else
602 		boot_command_line[0] = 0;
603 
604 #ifdef CONFIG_OF_EARLY_FLATTREE
605 	/*
606 	 * If we're configured to take boot arguments from DT, look for those
607 	 * now.
608 	 */
609 	if (IS_ENABLED(CONFIG_MIPS_CMDLINE_FROM_DTB) ||
610 	    IS_ENABLED(CONFIG_MIPS_CMDLINE_DTB_EXTEND))
611 		of_scan_flat_dt(bootcmdline_scan_chosen, &dt_bootargs);
612 #endif
613 
614 	/*
615 	 * If we didn't get any arguments from DT (regardless of whether that's
616 	 * because we weren't configured to look for them, or because we looked
617 	 * & found none) then we'll take arguments from the bootloader.
618 	 * plat_mem_setup() should have filled arcs_cmdline with arguments from
619 	 * the bootloader.
620 	 */
621 	if (IS_ENABLED(CONFIG_MIPS_CMDLINE_DTB_EXTEND) || !dt_bootargs)
622 		bootcmdline_append(arcs_cmdline, COMMAND_LINE_SIZE);
623 
624 	/*
625 	 * If the user specified a built-in command line & we didn't already
626 	 * prepend it, we append it to boot_command_line here.
627 	 */
628 	if (IS_ENABLED(CONFIG_CMDLINE_BOOL) &&
629 	    !IS_ENABLED(CONFIG_MIPS_CMDLINE_BUILTIN_EXTEND))
630 		bootcmdline_append(builtin_cmdline, COMMAND_LINE_SIZE);
631 }
632 
633 /*
634  * arch_mem_init - initialize memory management subsystem
635  *
636  *  o plat_mem_setup() detects the memory configuration and will record detected
637  *    memory areas using add_memory_region.
638  *
639  * At this stage the memory configuration of the system is known to the
640  * kernel but generic memory management system is still entirely uninitialized.
641  *
642  *  o bootmem_init()
643  *  o sparse_init()
644  *  o paging_init()
645  *  o dma_contiguous_reserve()
646  *
647  * At this stage the bootmem allocator is ready to use.
648  *
649  * NOTE: historically plat_mem_setup did the entire platform initialization.
650  *	 This was rather impractical because it meant plat_mem_setup had to
651  * get away without any kind of memory allocator.  To keep old code from
652  * breaking plat_setup was just renamed to plat_mem_setup and a second platform
653  * initialization hook for anything else was introduced.
654  */
655 static void __init arch_mem_init(char **cmdline_p)
656 {
657 	/* call board setup routine */
658 	plat_mem_setup();
659 	memblock_set_bottom_up(true);
660 
661 	bootcmdline_init();
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 
704 	/*
705 	 * In order to reduce the possibility of kernel panic when failed to
706 	 * get IO TLB memory under CONFIG_SWIOTLB, it is better to allocate
707 	 * low memory as small as possible before plat_swiotlb_setup(), so
708 	 * make sparse_init() using top-down allocation.
709 	 */
710 	memblock_set_bottom_up(false);
711 	sparse_init();
712 	memblock_set_bottom_up(true);
713 
714 	plat_swiotlb_setup();
715 
716 	dma_contiguous_reserve(PFN_PHYS(max_low_pfn));
717 
718 	/* Reserve for hibernation. */
719 	memblock_reserve(__pa_symbol(&__nosave_begin),
720 		__pa_symbol(&__nosave_end) - __pa_symbol(&__nosave_begin));
721 
722 	fdt_init_reserved_mem();
723 
724 	memblock_dump_all();
725 
726 	early_memtest(PFN_PHYS(ARCH_PFN_OFFSET), PFN_PHYS(max_low_pfn));
727 }
728 
729 static void __init resource_init(void)
730 {
731 	struct memblock_region *region;
732 
733 	if (UNCAC_BASE != IO_BASE)
734 		return;
735 
736 	code_resource.start = __pa_symbol(&_text);
737 	code_resource.end = __pa_symbol(&_etext) - 1;
738 	data_resource.start = __pa_symbol(&_etext);
739 	data_resource.end = __pa_symbol(&_edata) - 1;
740 	bss_resource.start = __pa_symbol(&__bss_start);
741 	bss_resource.end = __pa_symbol(&__bss_stop) - 1;
742 
743 	for_each_memblock(memory, region) {
744 		phys_addr_t start = PFN_PHYS(memblock_region_memory_base_pfn(region));
745 		phys_addr_t end = PFN_PHYS(memblock_region_memory_end_pfn(region)) - 1;
746 		struct resource *res;
747 
748 		res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);
749 		if (!res)
750 			panic("%s: Failed to allocate %zu bytes\n", __func__,
751 			      sizeof(struct resource));
752 
753 		res->start = start;
754 		res->end = end;
755 		res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
756 		res->name = "System RAM";
757 
758 		request_resource(&iomem_resource, res);
759 
760 		/*
761 		 *  We don't know which RAM region contains kernel data,
762 		 *  so we try it repeatedly and let the resource manager
763 		 *  test it.
764 		 */
765 		request_resource(res, &code_resource);
766 		request_resource(res, &data_resource);
767 		request_resource(res, &bss_resource);
768 		request_crashkernel(res);
769 	}
770 }
771 
772 #ifdef CONFIG_SMP
773 static void __init prefill_possible_map(void)
774 {
775 	int i, possible = num_possible_cpus();
776 
777 	if (possible > nr_cpu_ids)
778 		possible = nr_cpu_ids;
779 
780 	for (i = 0; i < possible; i++)
781 		set_cpu_possible(i, true);
782 	for (; i < NR_CPUS; i++)
783 		set_cpu_possible(i, false);
784 
785 	nr_cpu_ids = possible;
786 }
787 #else
788 static inline void prefill_possible_map(void) {}
789 #endif
790 
791 void __init setup_arch(char **cmdline_p)
792 {
793 	cpu_probe();
794 	mips_cm_probe();
795 	prom_init();
796 
797 	setup_early_fdc_console();
798 #ifdef CONFIG_EARLY_PRINTK
799 	setup_early_printk();
800 #endif
801 	cpu_report();
802 	check_bugs_early();
803 
804 #if defined(CONFIG_VT)
805 #if defined(CONFIG_VGA_CONSOLE)
806 	conswitchp = &vga_con;
807 #endif
808 #endif
809 
810 	arch_mem_init(cmdline_p);
811 	dmi_setup();
812 
813 	resource_init();
814 	plat_smp_setup();
815 	prefill_possible_map();
816 
817 	cpu_cache_init();
818 	paging_init();
819 }
820 
821 unsigned long kernelsp[NR_CPUS];
822 unsigned long fw_arg0, fw_arg1, fw_arg2, fw_arg3;
823 
824 #ifdef CONFIG_USE_OF
825 unsigned long fw_passed_dtb;
826 #endif
827 
828 #ifdef CONFIG_DEBUG_FS
829 struct dentry *mips_debugfs_dir;
830 static int __init debugfs_mips(void)
831 {
832 	mips_debugfs_dir = debugfs_create_dir("mips", NULL);
833 	return 0;
834 }
835 arch_initcall(debugfs_mips);
836 #endif
837 
838 #ifdef CONFIG_DMA_MAYBE_COHERENT
839 /* User defined DMA coherency from command line. */
840 enum coherent_io_user_state coherentio = IO_COHERENCE_DEFAULT;
841 EXPORT_SYMBOL_GPL(coherentio);
842 int hw_coherentio;	/* Actual hardware supported DMA coherency setting. */
843 
844 static int __init setcoherentio(char *str)
845 {
846 	coherentio = IO_COHERENCE_ENABLED;
847 	pr_info("Hardware DMA cache coherency (command line)\n");
848 	return 0;
849 }
850 early_param("coherentio", setcoherentio);
851 
852 static int __init setnocoherentio(char *str)
853 {
854 	coherentio = IO_COHERENCE_DISABLED;
855 	pr_info("Software DMA cache coherency (command line)\n");
856 	return 0;
857 }
858 early_param("nocoherentio", setnocoherentio);
859 #endif
860