xref: /openbmc/linux/arch/arm/kernel/setup.c (revision afb46f79)
1 /*
2  *  linux/arch/arm/kernel/setup.c
3  *
4  *  Copyright (C) 1995-2001 Russell King
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 #include <linux/export.h>
11 #include <linux/kernel.h>
12 #include <linux/stddef.h>
13 #include <linux/ioport.h>
14 #include <linux/delay.h>
15 #include <linux/utsname.h>
16 #include <linux/initrd.h>
17 #include <linux/console.h>
18 #include <linux/bootmem.h>
19 #include <linux/seq_file.h>
20 #include <linux/screen_info.h>
21 #include <linux/of_platform.h>
22 #include <linux/init.h>
23 #include <linux/kexec.h>
24 #include <linux/of_fdt.h>
25 #include <linux/cpu.h>
26 #include <linux/interrupt.h>
27 #include <linux/smp.h>
28 #include <linux/proc_fs.h>
29 #include <linux/memblock.h>
30 #include <linux/bug.h>
31 #include <linux/compiler.h>
32 #include <linux/sort.h>
33 
34 #include <asm/unified.h>
35 #include <asm/cp15.h>
36 #include <asm/cpu.h>
37 #include <asm/cputype.h>
38 #include <asm/elf.h>
39 #include <asm/procinfo.h>
40 #include <asm/psci.h>
41 #include <asm/sections.h>
42 #include <asm/setup.h>
43 #include <asm/smp_plat.h>
44 #include <asm/mach-types.h>
45 #include <asm/cacheflush.h>
46 #include <asm/cachetype.h>
47 #include <asm/tlbflush.h>
48 
49 #include <asm/prom.h>
50 #include <asm/mach/arch.h>
51 #include <asm/mach/irq.h>
52 #include <asm/mach/time.h>
53 #include <asm/system_info.h>
54 #include <asm/system_misc.h>
55 #include <asm/traps.h>
56 #include <asm/unwind.h>
57 #include <asm/memblock.h>
58 #include <asm/virt.h>
59 
60 #include "atags.h"
61 
62 
63 #if defined(CONFIG_FPE_NWFPE) || defined(CONFIG_FPE_FASTFPE)
64 char fpe_type[8];
65 
66 static int __init fpe_setup(char *line)
67 {
68 	memcpy(fpe_type, line, 8);
69 	return 1;
70 }
71 
72 __setup("fpe=", fpe_setup);
73 #endif
74 
75 extern void paging_init(const struct machine_desc *desc);
76 extern void early_paging_init(const struct machine_desc *,
77 			      struct proc_info_list *);
78 extern void sanity_check_meminfo(void);
79 extern enum reboot_mode reboot_mode;
80 extern void setup_dma_zone(const struct machine_desc *desc);
81 
82 unsigned int processor_id;
83 EXPORT_SYMBOL(processor_id);
84 unsigned int __machine_arch_type __read_mostly;
85 EXPORT_SYMBOL(__machine_arch_type);
86 unsigned int cacheid __read_mostly;
87 EXPORT_SYMBOL(cacheid);
88 
89 unsigned int __atags_pointer __initdata;
90 
91 unsigned int system_rev;
92 EXPORT_SYMBOL(system_rev);
93 
94 unsigned int system_serial_low;
95 EXPORT_SYMBOL(system_serial_low);
96 
97 unsigned int system_serial_high;
98 EXPORT_SYMBOL(system_serial_high);
99 
100 unsigned int elf_hwcap __read_mostly;
101 EXPORT_SYMBOL(elf_hwcap);
102 
103 unsigned int elf_hwcap2 __read_mostly;
104 EXPORT_SYMBOL(elf_hwcap2);
105 
106 
107 #ifdef MULTI_CPU
108 struct processor processor __read_mostly;
109 #endif
110 #ifdef MULTI_TLB
111 struct cpu_tlb_fns cpu_tlb __read_mostly;
112 #endif
113 #ifdef MULTI_USER
114 struct cpu_user_fns cpu_user __read_mostly;
115 #endif
116 #ifdef MULTI_CACHE
117 struct cpu_cache_fns cpu_cache __read_mostly;
118 #endif
119 #ifdef CONFIG_OUTER_CACHE
120 struct outer_cache_fns outer_cache __read_mostly;
121 EXPORT_SYMBOL(outer_cache);
122 #endif
123 
124 /*
125  * Cached cpu_architecture() result for use by assembler code.
126  * C code should use the cpu_architecture() function instead of accessing this
127  * variable directly.
128  */
129 int __cpu_architecture __read_mostly = CPU_ARCH_UNKNOWN;
130 
131 struct stack {
132 	u32 irq[3];
133 	u32 abt[3];
134 	u32 und[3];
135 } ____cacheline_aligned;
136 
137 #ifndef CONFIG_CPU_V7M
138 static struct stack stacks[NR_CPUS];
139 #endif
140 
141 char elf_platform[ELF_PLATFORM_SIZE];
142 EXPORT_SYMBOL(elf_platform);
143 
144 static const char *cpu_name;
145 static const char *machine_name;
146 static char __initdata cmd_line[COMMAND_LINE_SIZE];
147 const struct machine_desc *machine_desc __initdata;
148 
149 static union { char c[4]; unsigned long l; } endian_test __initdata = { { 'l', '?', '?', 'b' } };
150 #define ENDIANNESS ((char)endian_test.l)
151 
152 DEFINE_PER_CPU(struct cpuinfo_arm, cpu_data);
153 
154 /*
155  * Standard memory resources
156  */
157 static struct resource mem_res[] = {
158 	{
159 		.name = "Video RAM",
160 		.start = 0,
161 		.end = 0,
162 		.flags = IORESOURCE_MEM
163 	},
164 	{
165 		.name = "Kernel code",
166 		.start = 0,
167 		.end = 0,
168 		.flags = IORESOURCE_MEM
169 	},
170 	{
171 		.name = "Kernel data",
172 		.start = 0,
173 		.end = 0,
174 		.flags = IORESOURCE_MEM
175 	}
176 };
177 
178 #define video_ram   mem_res[0]
179 #define kernel_code mem_res[1]
180 #define kernel_data mem_res[2]
181 
182 static struct resource io_res[] = {
183 	{
184 		.name = "reserved",
185 		.start = 0x3bc,
186 		.end = 0x3be,
187 		.flags = IORESOURCE_IO | IORESOURCE_BUSY
188 	},
189 	{
190 		.name = "reserved",
191 		.start = 0x378,
192 		.end = 0x37f,
193 		.flags = IORESOURCE_IO | IORESOURCE_BUSY
194 	},
195 	{
196 		.name = "reserved",
197 		.start = 0x278,
198 		.end = 0x27f,
199 		.flags = IORESOURCE_IO | IORESOURCE_BUSY
200 	}
201 };
202 
203 #define lp0 io_res[0]
204 #define lp1 io_res[1]
205 #define lp2 io_res[2]
206 
207 static const char *proc_arch[] = {
208 	"undefined/unknown",
209 	"3",
210 	"4",
211 	"4T",
212 	"5",
213 	"5T",
214 	"5TE",
215 	"5TEJ",
216 	"6TEJ",
217 	"7",
218 	"7M",
219 	"?(12)",
220 	"?(13)",
221 	"?(14)",
222 	"?(15)",
223 	"?(16)",
224 	"?(17)",
225 };
226 
227 #ifdef CONFIG_CPU_V7M
228 static int __get_cpu_architecture(void)
229 {
230 	return CPU_ARCH_ARMv7M;
231 }
232 #else
233 static int __get_cpu_architecture(void)
234 {
235 	int cpu_arch;
236 
237 	if ((read_cpuid_id() & 0x0008f000) == 0) {
238 		cpu_arch = CPU_ARCH_UNKNOWN;
239 	} else if ((read_cpuid_id() & 0x0008f000) == 0x00007000) {
240 		cpu_arch = (read_cpuid_id() & (1 << 23)) ? CPU_ARCH_ARMv4T : CPU_ARCH_ARMv3;
241 	} else if ((read_cpuid_id() & 0x00080000) == 0x00000000) {
242 		cpu_arch = (read_cpuid_id() >> 16) & 7;
243 		if (cpu_arch)
244 			cpu_arch += CPU_ARCH_ARMv3;
245 	} else if ((read_cpuid_id() & 0x000f0000) == 0x000f0000) {
246 		unsigned int mmfr0;
247 
248 		/* Revised CPUID format. Read the Memory Model Feature
249 		 * Register 0 and check for VMSAv7 or PMSAv7 */
250 		asm("mrc	p15, 0, %0, c0, c1, 4"
251 		    : "=r" (mmfr0));
252 		if ((mmfr0 & 0x0000000f) >= 0x00000003 ||
253 		    (mmfr0 & 0x000000f0) >= 0x00000030)
254 			cpu_arch = CPU_ARCH_ARMv7;
255 		else if ((mmfr0 & 0x0000000f) == 0x00000002 ||
256 			 (mmfr0 & 0x000000f0) == 0x00000020)
257 			cpu_arch = CPU_ARCH_ARMv6;
258 		else
259 			cpu_arch = CPU_ARCH_UNKNOWN;
260 	} else
261 		cpu_arch = CPU_ARCH_UNKNOWN;
262 
263 	return cpu_arch;
264 }
265 #endif
266 
267 int __pure cpu_architecture(void)
268 {
269 	BUG_ON(__cpu_architecture == CPU_ARCH_UNKNOWN);
270 
271 	return __cpu_architecture;
272 }
273 
274 static int cpu_has_aliasing_icache(unsigned int arch)
275 {
276 	int aliasing_icache;
277 	unsigned int id_reg, num_sets, line_size;
278 
279 	/* PIPT caches never alias. */
280 	if (icache_is_pipt())
281 		return 0;
282 
283 	/* arch specifies the register format */
284 	switch (arch) {
285 	case CPU_ARCH_ARMv7:
286 		asm("mcr	p15, 2, %0, c0, c0, 0 @ set CSSELR"
287 		    : /* No output operands */
288 		    : "r" (1));
289 		isb();
290 		asm("mrc	p15, 1, %0, c0, c0, 0 @ read CCSIDR"
291 		    : "=r" (id_reg));
292 		line_size = 4 << ((id_reg & 0x7) + 2);
293 		num_sets = ((id_reg >> 13) & 0x7fff) + 1;
294 		aliasing_icache = (line_size * num_sets) > PAGE_SIZE;
295 		break;
296 	case CPU_ARCH_ARMv6:
297 		aliasing_icache = read_cpuid_cachetype() & (1 << 11);
298 		break;
299 	default:
300 		/* I-cache aliases will be handled by D-cache aliasing code */
301 		aliasing_icache = 0;
302 	}
303 
304 	return aliasing_icache;
305 }
306 
307 static void __init cacheid_init(void)
308 {
309 	unsigned int arch = cpu_architecture();
310 
311 	if (arch == CPU_ARCH_ARMv7M) {
312 		cacheid = 0;
313 	} else if (arch >= CPU_ARCH_ARMv6) {
314 		unsigned int cachetype = read_cpuid_cachetype();
315 		if ((cachetype & (7 << 29)) == 4 << 29) {
316 			/* ARMv7 register format */
317 			arch = CPU_ARCH_ARMv7;
318 			cacheid = CACHEID_VIPT_NONALIASING;
319 			switch (cachetype & (3 << 14)) {
320 			case (1 << 14):
321 				cacheid |= CACHEID_ASID_TAGGED;
322 				break;
323 			case (3 << 14):
324 				cacheid |= CACHEID_PIPT;
325 				break;
326 			}
327 		} else {
328 			arch = CPU_ARCH_ARMv6;
329 			if (cachetype & (1 << 23))
330 				cacheid = CACHEID_VIPT_ALIASING;
331 			else
332 				cacheid = CACHEID_VIPT_NONALIASING;
333 		}
334 		if (cpu_has_aliasing_icache(arch))
335 			cacheid |= CACHEID_VIPT_I_ALIASING;
336 	} else {
337 		cacheid = CACHEID_VIVT;
338 	}
339 
340 	pr_info("CPU: %s data cache, %s instruction cache\n",
341 		cache_is_vivt() ? "VIVT" :
342 		cache_is_vipt_aliasing() ? "VIPT aliasing" :
343 		cache_is_vipt_nonaliasing() ? "PIPT / VIPT nonaliasing" : "unknown",
344 		cache_is_vivt() ? "VIVT" :
345 		icache_is_vivt_asid_tagged() ? "VIVT ASID tagged" :
346 		icache_is_vipt_aliasing() ? "VIPT aliasing" :
347 		icache_is_pipt() ? "PIPT" :
348 		cache_is_vipt_nonaliasing() ? "VIPT nonaliasing" : "unknown");
349 }
350 
351 /*
352  * These functions re-use the assembly code in head.S, which
353  * already provide the required functionality.
354  */
355 extern struct proc_info_list *lookup_processor_type(unsigned int);
356 
357 void __init early_print(const char *str, ...)
358 {
359 	extern void printascii(const char *);
360 	char buf[256];
361 	va_list ap;
362 
363 	va_start(ap, str);
364 	vsnprintf(buf, sizeof(buf), str, ap);
365 	va_end(ap);
366 
367 #ifdef CONFIG_DEBUG_LL
368 	printascii(buf);
369 #endif
370 	printk("%s", buf);
371 }
372 
373 static void __init cpuid_init_hwcaps(void)
374 {
375 	unsigned int divide_instrs, vmsa;
376 
377 	if (cpu_architecture() < CPU_ARCH_ARMv7)
378 		return;
379 
380 	divide_instrs = (read_cpuid_ext(CPUID_EXT_ISAR0) & 0x0f000000) >> 24;
381 
382 	switch (divide_instrs) {
383 	case 2:
384 		elf_hwcap |= HWCAP_IDIVA;
385 	case 1:
386 		elf_hwcap |= HWCAP_IDIVT;
387 	}
388 
389 	/* LPAE implies atomic ldrd/strd instructions */
390 	vmsa = (read_cpuid_ext(CPUID_EXT_MMFR0) & 0xf) >> 0;
391 	if (vmsa >= 5)
392 		elf_hwcap |= HWCAP_LPAE;
393 }
394 
395 static void __init feat_v6_fixup(void)
396 {
397 	int id = read_cpuid_id();
398 
399 	if ((id & 0xff0f0000) != 0x41070000)
400 		return;
401 
402 	/*
403 	 * HWCAP_TLS is available only on 1136 r1p0 and later,
404 	 * see also kuser_get_tls_init.
405 	 */
406 	if ((((id >> 4) & 0xfff) == 0xb36) && (((id >> 20) & 3) == 0))
407 		elf_hwcap &= ~HWCAP_TLS;
408 }
409 
410 /*
411  * cpu_init - initialise one CPU.
412  *
413  * cpu_init sets up the per-CPU stacks.
414  */
415 void notrace cpu_init(void)
416 {
417 #ifndef CONFIG_CPU_V7M
418 	unsigned int cpu = smp_processor_id();
419 	struct stack *stk = &stacks[cpu];
420 
421 	if (cpu >= NR_CPUS) {
422 		pr_crit("CPU%u: bad primary CPU number\n", cpu);
423 		BUG();
424 	}
425 
426 	/*
427 	 * This only works on resume and secondary cores. For booting on the
428 	 * boot cpu, smp_prepare_boot_cpu is called after percpu area setup.
429 	 */
430 	set_my_cpu_offset(per_cpu_offset(cpu));
431 
432 	cpu_proc_init();
433 
434 	/*
435 	 * Define the placement constraint for the inline asm directive below.
436 	 * In Thumb-2, msr with an immediate value is not allowed.
437 	 */
438 #ifdef CONFIG_THUMB2_KERNEL
439 #define PLC	"r"
440 #else
441 #define PLC	"I"
442 #endif
443 
444 	/*
445 	 * setup stacks for re-entrant exception handlers
446 	 */
447 	__asm__ (
448 	"msr	cpsr_c, %1\n\t"
449 	"add	r14, %0, %2\n\t"
450 	"mov	sp, r14\n\t"
451 	"msr	cpsr_c, %3\n\t"
452 	"add	r14, %0, %4\n\t"
453 	"mov	sp, r14\n\t"
454 	"msr	cpsr_c, %5\n\t"
455 	"add	r14, %0, %6\n\t"
456 	"mov	sp, r14\n\t"
457 	"msr	cpsr_c, %7"
458 	    :
459 	    : "r" (stk),
460 	      PLC (PSR_F_BIT | PSR_I_BIT | IRQ_MODE),
461 	      "I" (offsetof(struct stack, irq[0])),
462 	      PLC (PSR_F_BIT | PSR_I_BIT | ABT_MODE),
463 	      "I" (offsetof(struct stack, abt[0])),
464 	      PLC (PSR_F_BIT | PSR_I_BIT | UND_MODE),
465 	      "I" (offsetof(struct stack, und[0])),
466 	      PLC (PSR_F_BIT | PSR_I_BIT | SVC_MODE)
467 	    : "r14");
468 #endif
469 }
470 
471 u32 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = MPIDR_INVALID };
472 
473 void __init smp_setup_processor_id(void)
474 {
475 	int i;
476 	u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;
477 	u32 cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
478 
479 	cpu_logical_map(0) = cpu;
480 	for (i = 1; i < nr_cpu_ids; ++i)
481 		cpu_logical_map(i) = i == cpu ? 0 : i;
482 
483 	/*
484 	 * clear __my_cpu_offset on boot CPU to avoid hang caused by
485 	 * using percpu variable early, for example, lockdep will
486 	 * access percpu variable inside lock_release
487 	 */
488 	set_my_cpu_offset(0);
489 
490 	pr_info("Booting Linux on physical CPU 0x%x\n", mpidr);
491 }
492 
493 struct mpidr_hash mpidr_hash;
494 #ifdef CONFIG_SMP
495 /**
496  * smp_build_mpidr_hash - Pre-compute shifts required at each affinity
497  *			  level in order to build a linear index from an
498  *			  MPIDR value. Resulting algorithm is a collision
499  *			  free hash carried out through shifting and ORing
500  */
501 static void __init smp_build_mpidr_hash(void)
502 {
503 	u32 i, affinity;
504 	u32 fs[3], bits[3], ls, mask = 0;
505 	/*
506 	 * Pre-scan the list of MPIDRS and filter out bits that do
507 	 * not contribute to affinity levels, ie they never toggle.
508 	 */
509 	for_each_possible_cpu(i)
510 		mask |= (cpu_logical_map(i) ^ cpu_logical_map(0));
511 	pr_debug("mask of set bits 0x%x\n", mask);
512 	/*
513 	 * Find and stash the last and first bit set at all affinity levels to
514 	 * check how many bits are required to represent them.
515 	 */
516 	for (i = 0; i < 3; i++) {
517 		affinity = MPIDR_AFFINITY_LEVEL(mask, i);
518 		/*
519 		 * Find the MSB bit and LSB bits position
520 		 * to determine how many bits are required
521 		 * to express the affinity level.
522 		 */
523 		ls = fls(affinity);
524 		fs[i] = affinity ? ffs(affinity) - 1 : 0;
525 		bits[i] = ls - fs[i];
526 	}
527 	/*
528 	 * An index can be created from the MPIDR by isolating the
529 	 * significant bits at each affinity level and by shifting
530 	 * them in order to compress the 24 bits values space to a
531 	 * compressed set of values. This is equivalent to hashing
532 	 * the MPIDR through shifting and ORing. It is a collision free
533 	 * hash though not minimal since some levels might contain a number
534 	 * of CPUs that is not an exact power of 2 and their bit
535 	 * representation might contain holes, eg MPIDR[7:0] = {0x2, 0x80}.
536 	 */
537 	mpidr_hash.shift_aff[0] = fs[0];
538 	mpidr_hash.shift_aff[1] = MPIDR_LEVEL_BITS + fs[1] - bits[0];
539 	mpidr_hash.shift_aff[2] = 2*MPIDR_LEVEL_BITS + fs[2] -
540 						(bits[1] + bits[0]);
541 	mpidr_hash.mask = mask;
542 	mpidr_hash.bits = bits[2] + bits[1] + bits[0];
543 	pr_debug("MPIDR hash: aff0[%u] aff1[%u] aff2[%u] mask[0x%x] bits[%u]\n",
544 				mpidr_hash.shift_aff[0],
545 				mpidr_hash.shift_aff[1],
546 				mpidr_hash.shift_aff[2],
547 				mpidr_hash.mask,
548 				mpidr_hash.bits);
549 	/*
550 	 * 4x is an arbitrary value used to warn on a hash table much bigger
551 	 * than expected on most systems.
552 	 */
553 	if (mpidr_hash_size() > 4 * num_possible_cpus())
554 		pr_warn("Large number of MPIDR hash buckets detected\n");
555 	sync_cache_w(&mpidr_hash);
556 }
557 #endif
558 
559 static void __init setup_processor(void)
560 {
561 	struct proc_info_list *list;
562 
563 	/*
564 	 * locate processor in the list of supported processor
565 	 * types.  The linker builds this table for us from the
566 	 * entries in arch/arm/mm/proc-*.S
567 	 */
568 	list = lookup_processor_type(read_cpuid_id());
569 	if (!list) {
570 		pr_err("CPU configuration botched (ID %08x), unable to continue.\n",
571 		       read_cpuid_id());
572 		while (1);
573 	}
574 
575 	cpu_name = list->cpu_name;
576 	__cpu_architecture = __get_cpu_architecture();
577 
578 #ifdef MULTI_CPU
579 	processor = *list->proc;
580 #endif
581 #ifdef MULTI_TLB
582 	cpu_tlb = *list->tlb;
583 #endif
584 #ifdef MULTI_USER
585 	cpu_user = *list->user;
586 #endif
587 #ifdef MULTI_CACHE
588 	cpu_cache = *list->cache;
589 #endif
590 
591 	pr_info("CPU: %s [%08x] revision %d (ARMv%s), cr=%08lx\n",
592 		cpu_name, read_cpuid_id(), read_cpuid_id() & 15,
593 		proc_arch[cpu_architecture()], cr_alignment);
594 
595 	snprintf(init_utsname()->machine, __NEW_UTS_LEN + 1, "%s%c",
596 		 list->arch_name, ENDIANNESS);
597 	snprintf(elf_platform, ELF_PLATFORM_SIZE, "%s%c",
598 		 list->elf_name, ENDIANNESS);
599 	elf_hwcap = list->elf_hwcap;
600 
601 	cpuid_init_hwcaps();
602 
603 #ifndef CONFIG_ARM_THUMB
604 	elf_hwcap &= ~(HWCAP_THUMB | HWCAP_IDIVT);
605 #endif
606 
607 	erratum_a15_798181_init();
608 
609 	feat_v6_fixup();
610 
611 	cacheid_init();
612 	cpu_init();
613 }
614 
615 void __init dump_machine_table(void)
616 {
617 	const struct machine_desc *p;
618 
619 	early_print("Available machine support:\n\nID (hex)\tNAME\n");
620 	for_each_machine_desc(p)
621 		early_print("%08x\t%s\n", p->nr, p->name);
622 
623 	early_print("\nPlease check your kernel config and/or bootloader.\n");
624 
625 	while (true)
626 		/* can't use cpu_relax() here as it may require MMU setup */;
627 }
628 
629 int __init arm_add_memory(u64 start, u64 size)
630 {
631 	struct membank *bank = &meminfo.bank[meminfo.nr_banks];
632 	u64 aligned_start;
633 
634 	if (meminfo.nr_banks >= NR_BANKS) {
635 		pr_crit("NR_BANKS too low, ignoring memory at 0x%08llx\n",
636 			(long long)start);
637 		return -EINVAL;
638 	}
639 
640 	/*
641 	 * Ensure that start/size are aligned to a page boundary.
642 	 * Size is appropriately rounded down, start is rounded up.
643 	 */
644 	size -= start & ~PAGE_MASK;
645 	aligned_start = PAGE_ALIGN(start);
646 
647 #ifndef CONFIG_ARCH_PHYS_ADDR_T_64BIT
648 	if (aligned_start > ULONG_MAX) {
649 		pr_crit("Ignoring memory at 0x%08llx outside 32-bit physical address space\n",
650 			(long long)start);
651 		return -EINVAL;
652 	}
653 
654 	if (aligned_start + size > ULONG_MAX) {
655 		pr_crit("Truncating memory at 0x%08llx to fit in 32-bit physical address space\n",
656 			(long long)start);
657 		/*
658 		 * To ensure bank->start + bank->size is representable in
659 		 * 32 bits, we use ULONG_MAX as the upper limit rather than 4GB.
660 		 * This means we lose a page after masking.
661 		 */
662 		size = ULONG_MAX - aligned_start;
663 	}
664 #endif
665 
666 	if (aligned_start < PHYS_OFFSET) {
667 		if (aligned_start + size <= PHYS_OFFSET) {
668 			pr_info("Ignoring memory below PHYS_OFFSET: 0x%08llx-0x%08llx\n",
669 				aligned_start, aligned_start + size);
670 			return -EINVAL;
671 		}
672 
673 		pr_info("Ignoring memory below PHYS_OFFSET: 0x%08llx-0x%08llx\n",
674 			aligned_start, (u64)PHYS_OFFSET);
675 
676 		size -= PHYS_OFFSET - aligned_start;
677 		aligned_start = PHYS_OFFSET;
678 	}
679 
680 	bank->start = aligned_start;
681 	bank->size = size & ~(phys_addr_t)(PAGE_SIZE - 1);
682 
683 	/*
684 	 * Check whether this memory region has non-zero size or
685 	 * invalid node number.
686 	 */
687 	if (bank->size == 0)
688 		return -EINVAL;
689 
690 	meminfo.nr_banks++;
691 	return 0;
692 }
693 
694 /*
695  * Pick out the memory size.  We look for mem=size@start,
696  * where start and size are "size[KkMm]"
697  */
698 static int __init early_mem(char *p)
699 {
700 	static int usermem __initdata = 0;
701 	u64 size;
702 	u64 start;
703 	char *endp;
704 
705 	/*
706 	 * If the user specifies memory size, we
707 	 * blow away any automatically generated
708 	 * size.
709 	 */
710 	if (usermem == 0) {
711 		usermem = 1;
712 		meminfo.nr_banks = 0;
713 	}
714 
715 	start = PHYS_OFFSET;
716 	size  = memparse(p, &endp);
717 	if (*endp == '@')
718 		start = memparse(endp + 1, NULL);
719 
720 	arm_add_memory(start, size);
721 
722 	return 0;
723 }
724 early_param("mem", early_mem);
725 
726 static void __init request_standard_resources(const struct machine_desc *mdesc)
727 {
728 	struct memblock_region *region;
729 	struct resource *res;
730 
731 	kernel_code.start   = virt_to_phys(_text);
732 	kernel_code.end     = virt_to_phys(_etext - 1);
733 	kernel_data.start   = virt_to_phys(_sdata);
734 	kernel_data.end     = virt_to_phys(_end - 1);
735 
736 	for_each_memblock(memory, region) {
737 		res = memblock_virt_alloc(sizeof(*res), 0);
738 		res->name  = "System RAM";
739 		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
740 		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
741 		res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
742 
743 		request_resource(&iomem_resource, res);
744 
745 		if (kernel_code.start >= res->start &&
746 		    kernel_code.end <= res->end)
747 			request_resource(res, &kernel_code);
748 		if (kernel_data.start >= res->start &&
749 		    kernel_data.end <= res->end)
750 			request_resource(res, &kernel_data);
751 	}
752 
753 	if (mdesc->video_start) {
754 		video_ram.start = mdesc->video_start;
755 		video_ram.end   = mdesc->video_end;
756 		request_resource(&iomem_resource, &video_ram);
757 	}
758 
759 	/*
760 	 * Some machines don't have the possibility of ever
761 	 * possessing lp0, lp1 or lp2
762 	 */
763 	if (mdesc->reserve_lp0)
764 		request_resource(&ioport_resource, &lp0);
765 	if (mdesc->reserve_lp1)
766 		request_resource(&ioport_resource, &lp1);
767 	if (mdesc->reserve_lp2)
768 		request_resource(&ioport_resource, &lp2);
769 }
770 
771 #if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE)
772 struct screen_info screen_info = {
773  .orig_video_lines	= 30,
774  .orig_video_cols	= 80,
775  .orig_video_mode	= 0,
776  .orig_video_ega_bx	= 0,
777  .orig_video_isVGA	= 1,
778  .orig_video_points	= 8
779 };
780 #endif
781 
782 static int __init customize_machine(void)
783 {
784 	/*
785 	 * customizes platform devices, or adds new ones
786 	 * On DT based machines, we fall back to populating the
787 	 * machine from the device tree, if no callback is provided,
788 	 * otherwise we would always need an init_machine callback.
789 	 */
790 	if (machine_desc->init_machine)
791 		machine_desc->init_machine();
792 #ifdef CONFIG_OF
793 	else
794 		of_platform_populate(NULL, of_default_bus_match_table,
795 					NULL, NULL);
796 #endif
797 	return 0;
798 }
799 arch_initcall(customize_machine);
800 
801 static int __init init_machine_late(void)
802 {
803 	if (machine_desc->init_late)
804 		machine_desc->init_late();
805 	return 0;
806 }
807 late_initcall(init_machine_late);
808 
809 #ifdef CONFIG_KEXEC
810 static inline unsigned long long get_total_mem(void)
811 {
812 	unsigned long total;
813 
814 	total = max_low_pfn - min_low_pfn;
815 	return total << PAGE_SHIFT;
816 }
817 
818 /**
819  * reserve_crashkernel() - reserves memory are for crash kernel
820  *
821  * This function reserves memory area given in "crashkernel=" kernel command
822  * line parameter. The memory reserved is used by a dump capture kernel when
823  * primary kernel is crashing.
824  */
825 static void __init reserve_crashkernel(void)
826 {
827 	unsigned long long crash_size, crash_base;
828 	unsigned long long total_mem;
829 	int ret;
830 
831 	total_mem = get_total_mem();
832 	ret = parse_crashkernel(boot_command_line, total_mem,
833 				&crash_size, &crash_base);
834 	if (ret)
835 		return;
836 
837 	ret = memblock_reserve(crash_base, crash_size);
838 	if (ret < 0) {
839 		pr_warn("crashkernel reservation failed - memory is in use (0x%lx)\n",
840 			(unsigned long)crash_base);
841 		return;
842 	}
843 
844 	pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n",
845 		(unsigned long)(crash_size >> 20),
846 		(unsigned long)(crash_base >> 20),
847 		(unsigned long)(total_mem >> 20));
848 
849 	crashk_res.start = crash_base;
850 	crashk_res.end = crash_base + crash_size - 1;
851 	insert_resource(&iomem_resource, &crashk_res);
852 }
853 #else
854 static inline void reserve_crashkernel(void) {}
855 #endif /* CONFIG_KEXEC */
856 
857 static int __init meminfo_cmp(const void *_a, const void *_b)
858 {
859 	const struct membank *a = _a, *b = _b;
860 	long cmp = bank_pfn_start(a) - bank_pfn_start(b);
861 	return cmp < 0 ? -1 : cmp > 0 ? 1 : 0;
862 }
863 
864 void __init hyp_mode_check(void)
865 {
866 #ifdef CONFIG_ARM_VIRT_EXT
867 	sync_boot_mode();
868 
869 	if (is_hyp_mode_available()) {
870 		pr_info("CPU: All CPU(s) started in HYP mode.\n");
871 		pr_info("CPU: Virtualization extensions available.\n");
872 	} else if (is_hyp_mode_mismatched()) {
873 		pr_warn("CPU: WARNING: CPU(s) started in wrong/inconsistent modes (primary CPU mode 0x%x)\n",
874 			__boot_cpu_mode & MODE_MASK);
875 		pr_warn("CPU: This may indicate a broken bootloader or firmware.\n");
876 	} else
877 		pr_info("CPU: All CPU(s) started in SVC mode.\n");
878 #endif
879 }
880 
881 void __init setup_arch(char **cmdline_p)
882 {
883 	const struct machine_desc *mdesc;
884 
885 	setup_processor();
886 	mdesc = setup_machine_fdt(__atags_pointer);
887 	if (!mdesc)
888 		mdesc = setup_machine_tags(__atags_pointer, __machine_arch_type);
889 	machine_desc = mdesc;
890 	machine_name = mdesc->name;
891 
892 	if (mdesc->reboot_mode != REBOOT_HARD)
893 		reboot_mode = mdesc->reboot_mode;
894 
895 	init_mm.start_code = (unsigned long) _text;
896 	init_mm.end_code   = (unsigned long) _etext;
897 	init_mm.end_data   = (unsigned long) _edata;
898 	init_mm.brk	   = (unsigned long) _end;
899 
900 	/* populate cmd_line too for later use, preserving boot_command_line */
901 	strlcpy(cmd_line, boot_command_line, COMMAND_LINE_SIZE);
902 	*cmdline_p = cmd_line;
903 
904 	parse_early_param();
905 
906 	sort(&meminfo.bank, meminfo.nr_banks, sizeof(meminfo.bank[0]), meminfo_cmp, NULL);
907 
908 	early_paging_init(mdesc, lookup_processor_type(read_cpuid_id()));
909 	setup_dma_zone(mdesc);
910 	sanity_check_meminfo();
911 	arm_memblock_init(&meminfo, mdesc);
912 
913 	paging_init(mdesc);
914 	request_standard_resources(mdesc);
915 
916 	if (mdesc->restart)
917 		arm_pm_restart = mdesc->restart;
918 
919 	unflatten_device_tree();
920 
921 	arm_dt_init_cpu_maps();
922 	psci_init();
923 #ifdef CONFIG_SMP
924 	if (is_smp()) {
925 		if (!mdesc->smp_init || !mdesc->smp_init()) {
926 			if (psci_smp_available())
927 				smp_set_ops(&psci_smp_ops);
928 			else if (mdesc->smp)
929 				smp_set_ops(mdesc->smp);
930 		}
931 		smp_init_cpus();
932 		smp_build_mpidr_hash();
933 	}
934 #endif
935 
936 	if (!is_smp())
937 		hyp_mode_check();
938 
939 	reserve_crashkernel();
940 
941 #ifdef CONFIG_MULTI_IRQ_HANDLER
942 	handle_arch_irq = mdesc->handle_irq;
943 #endif
944 
945 #ifdef CONFIG_VT
946 #if defined(CONFIG_VGA_CONSOLE)
947 	conswitchp = &vga_con;
948 #elif defined(CONFIG_DUMMY_CONSOLE)
949 	conswitchp = &dummy_con;
950 #endif
951 #endif
952 
953 	if (mdesc->init_early)
954 		mdesc->init_early();
955 }
956 
957 
958 static int __init topology_init(void)
959 {
960 	int cpu;
961 
962 	for_each_possible_cpu(cpu) {
963 		struct cpuinfo_arm *cpuinfo = &per_cpu(cpu_data, cpu);
964 		cpuinfo->cpu.hotpluggable = 1;
965 		register_cpu(&cpuinfo->cpu, cpu);
966 	}
967 
968 	return 0;
969 }
970 subsys_initcall(topology_init);
971 
972 #ifdef CONFIG_HAVE_PROC_CPU
973 static int __init proc_cpu_init(void)
974 {
975 	struct proc_dir_entry *res;
976 
977 	res = proc_mkdir("cpu", NULL);
978 	if (!res)
979 		return -ENOMEM;
980 	return 0;
981 }
982 fs_initcall(proc_cpu_init);
983 #endif
984 
985 static const char *hwcap_str[] = {
986 	"swp",
987 	"half",
988 	"thumb",
989 	"26bit",
990 	"fastmult",
991 	"fpa",
992 	"vfp",
993 	"edsp",
994 	"java",
995 	"iwmmxt",
996 	"crunch",
997 	"thumbee",
998 	"neon",
999 	"vfpv3",
1000 	"vfpv3d16",
1001 	"tls",
1002 	"vfpv4",
1003 	"idiva",
1004 	"idivt",
1005 	"vfpd32",
1006 	"lpae",
1007 	"evtstrm",
1008 	NULL
1009 };
1010 
1011 static const char *hwcap2_str[] = {
1012 	"aes",
1013 	"pmull",
1014 	"sha1",
1015 	"sha2",
1016 	"crc32",
1017 	NULL
1018 };
1019 
1020 static int c_show(struct seq_file *m, void *v)
1021 {
1022 	int i, j;
1023 	u32 cpuid;
1024 
1025 	for_each_online_cpu(i) {
1026 		/*
1027 		 * glibc reads /proc/cpuinfo to determine the number of
1028 		 * online processors, looking for lines beginning with
1029 		 * "processor".  Give glibc what it expects.
1030 		 */
1031 		seq_printf(m, "processor\t: %d\n", i);
1032 		cpuid = is_smp() ? per_cpu(cpu_data, i).cpuid : read_cpuid_id();
1033 		seq_printf(m, "model name\t: %s rev %d (%s)\n",
1034 			   cpu_name, cpuid & 15, elf_platform);
1035 
1036 		/* dump out the processor features */
1037 		seq_puts(m, "Features\t: ");
1038 
1039 		for (j = 0; hwcap_str[j]; j++)
1040 			if (elf_hwcap & (1 << j))
1041 				seq_printf(m, "%s ", hwcap_str[j]);
1042 
1043 		for (j = 0; hwcap2_str[j]; j++)
1044 			if (elf_hwcap2 & (1 << j))
1045 				seq_printf(m, "%s ", hwcap2_str[j]);
1046 
1047 		seq_printf(m, "\nCPU implementer\t: 0x%02x\n", cpuid >> 24);
1048 		seq_printf(m, "CPU architecture: %s\n",
1049 			   proc_arch[cpu_architecture()]);
1050 
1051 		if ((cpuid & 0x0008f000) == 0x00000000) {
1052 			/* pre-ARM7 */
1053 			seq_printf(m, "CPU part\t: %07x\n", cpuid >> 4);
1054 		} else {
1055 			if ((cpuid & 0x0008f000) == 0x00007000) {
1056 				/* ARM7 */
1057 				seq_printf(m, "CPU variant\t: 0x%02x\n",
1058 					   (cpuid >> 16) & 127);
1059 			} else {
1060 				/* post-ARM7 */
1061 				seq_printf(m, "CPU variant\t: 0x%x\n",
1062 					   (cpuid >> 20) & 15);
1063 			}
1064 			seq_printf(m, "CPU part\t: 0x%03x\n",
1065 				   (cpuid >> 4) & 0xfff);
1066 		}
1067 		seq_printf(m, "CPU revision\t: %d\n\n", cpuid & 15);
1068 	}
1069 
1070 	seq_printf(m, "Hardware\t: %s\n", machine_name);
1071 	seq_printf(m, "Revision\t: %04x\n", system_rev);
1072 	seq_printf(m, "Serial\t\t: %08x%08x\n",
1073 		   system_serial_high, system_serial_low);
1074 
1075 	return 0;
1076 }
1077 
1078 static void *c_start(struct seq_file *m, loff_t *pos)
1079 {
1080 	return *pos < 1 ? (void *)1 : NULL;
1081 }
1082 
1083 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
1084 {
1085 	++*pos;
1086 	return NULL;
1087 }
1088 
1089 static void c_stop(struct seq_file *m, void *v)
1090 {
1091 }
1092 
1093 const struct seq_operations cpuinfo_op = {
1094 	.start	= c_start,
1095 	.next	= c_next,
1096 	.stop	= c_stop,
1097 	.show	= c_show
1098 };
1099