xref: /openbmc/linux/arch/arc/kernel/setup.c (revision 7ce2e76a) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4  */
5 
6 #include <linux/seq_file.h>
7 #include <linux/fs.h>
8 #include <linux/delay.h>
9 #include <linux/root_dev.h>
10 #include <linux/clk.h>
11 #include <linux/clk-provider.h>
12 #include <linux/clocksource.h>
13 #include <linux/console.h>
14 #include <linux/module.h>
15 #include <linux/cpu.h>
16 #include <linux/of_fdt.h>
17 #include <linux/of.h>
18 #include <linux/cache.h>
19 #include <uapi/linux/mount.h>
20 #include <asm/sections.h>
21 #include <asm/arcregs.h>
22 #include <asm/tlb.h>
23 #include <asm/setup.h>
24 #include <asm/page.h>
25 #include <asm/irq.h>
26 #include <asm/unwind.h>
27 #include <asm/mach_desc.h>
28 #include <asm/smp.h>
29 
30 #define FIX_PTR(x)  __asm__ __volatile__(";" : "+r"(x))
31 
32 unsigned int intr_to_DE_cnt;
33 
34 /* Part of U-boot ABI: see head.S */
35 int __initdata uboot_tag;
36 int __initdata uboot_magic;
37 char __initdata *uboot_arg;
38 
39 const struct machine_desc *machine_desc;
40 
41 struct task_struct *_current_task[NR_CPUS];	/* For stack switching */
42 
43 struct cpuinfo_arc cpuinfo_arc700[NR_CPUS];
44 
45 static const struct id_to_str arc_legacy_rel[] = {
46 	/* ID.ARCVER,	Release */
47 #ifdef CONFIG_ISA_ARCOMPACT
48 	{ 0x34, 	"R4.10"},
49 	{ 0x35, 	"R4.11"},
50 #else
51 	{ 0x51, 	"R2.0" },
52 	{ 0x52, 	"R2.1" },
53 	{ 0x53,		"R3.0" },
54 #endif
55 	{ 0x00,		NULL   }
56 };
57 
58 static const struct id_to_str arc_cpu_rel[] = {
59 	/* UARCH.MAJOR,	Release */
60 	{  0,		"R3.10a"},
61 	{  1,		"R3.50a"},
62 	{  0xFF,	NULL   }
63 };
64 
65 static void read_decode_ccm_bcr(struct cpuinfo_arc *cpu)
66 {
67 	if (is_isa_arcompact()) {
68 		struct bcr_iccm_arcompact iccm;
69 		struct bcr_dccm_arcompact dccm;
70 
71 		READ_BCR(ARC_REG_ICCM_BUILD, iccm);
72 		if (iccm.ver) {
73 			cpu->iccm.sz = 4096 << iccm.sz;	/* 8K to 512K */
74 			cpu->iccm.base_addr = iccm.base << 16;
75 		}
76 
77 		READ_BCR(ARC_REG_DCCM_BUILD, dccm);
78 		if (dccm.ver) {
79 			unsigned long base;
80 			cpu->dccm.sz = 2048 << dccm.sz;	/* 2K to 256K */
81 
82 			base = read_aux_reg(ARC_REG_DCCM_BASE_BUILD);
83 			cpu->dccm.base_addr = base & ~0xF;
84 		}
85 	} else {
86 		struct bcr_iccm_arcv2 iccm;
87 		struct bcr_dccm_arcv2 dccm;
88 		unsigned long region;
89 
90 		READ_BCR(ARC_REG_ICCM_BUILD, iccm);
91 		if (iccm.ver) {
92 			cpu->iccm.sz = 256 << iccm.sz00;	/* 512B to 16M */
93 			if (iccm.sz00 == 0xF && iccm.sz01 > 0)
94 				cpu->iccm.sz <<= iccm.sz01;
95 
96 			region = read_aux_reg(ARC_REG_AUX_ICCM);
97 			cpu->iccm.base_addr = region & 0xF0000000;
98 		}
99 
100 		READ_BCR(ARC_REG_DCCM_BUILD, dccm);
101 		if (dccm.ver) {
102 			cpu->dccm.sz = 256 << dccm.sz0;
103 			if (dccm.sz0 == 0xF && dccm.sz1 > 0)
104 				cpu->dccm.sz <<= dccm.sz1;
105 
106 			region = read_aux_reg(ARC_REG_AUX_DCCM);
107 			cpu->dccm.base_addr = region & 0xF0000000;
108 		}
109 	}
110 }
111 
112 static void decode_arc_core(struct cpuinfo_arc *cpu)
113 {
114 	struct bcr_uarch_build_arcv2 uarch;
115 	const struct id_to_str *tbl;
116 
117 	/*
118 	 * Up until (including) the first core4 release (0x54) things were
119 	 * simple: AUX IDENTITY.ARCVER was sufficient to identify arc family
120 	 * and release: 0x50 to 0x53 was HS38, 0x54 was HS48 (dual issue)
121 	 */
122 
123 	if (cpu->core.family < 0x54) { /* includes arc700 */
124 
125 		for (tbl = &arc_legacy_rel[0]; tbl->id != 0; tbl++) {
126 			if (cpu->core.family == tbl->id) {
127 				cpu->release = tbl->str;
128 				break;
129 			}
130 		}
131 
132 		if (is_isa_arcompact())
133 			cpu->name = "ARC700";
134 		else if (tbl->str)
135 			cpu->name = "HS38";
136 		else
137 			cpu->name = cpu->release = "Unknown";
138 
139 		return;
140 	}
141 
142 	/*
143 	 * However the subsequent HS release (same 0x54) allow HS38 or HS48
144 	 * configurations and encode this info in a different BCR.
145 	 * The BCR was introduced in 0x54 so can't be read unconditionally.
146 	 */
147 
148 	READ_BCR(ARC_REG_MICRO_ARCH_BCR, uarch);
149 
150 	if (uarch.prod == 4) {
151 		cpu->name = "HS48";
152 		cpu->extn.dual = 1;
153 
154 	} else {
155 		cpu->name = "HS38";
156 	}
157 
158 	for (tbl = &arc_cpu_rel[0]; tbl->id != 0xFF; tbl++) {
159 		if (uarch.maj == tbl->id) {
160 			cpu->release = tbl->str;
161 			break;
162 		}
163 	}
164 }
165 
166 static void read_arc_build_cfg_regs(void)
167 {
168 	struct bcr_timer timer;
169 	struct bcr_generic bcr;
170 	struct cpuinfo_arc *cpu = &cpuinfo_arc700[smp_processor_id()];
171 	struct bcr_isa_arcv2 isa;
172 	struct bcr_actionpoint ap;
173 
174 	FIX_PTR(cpu);
175 
176 	READ_BCR(AUX_IDENTITY, cpu->core);
177 	decode_arc_core(cpu);
178 
179 	READ_BCR(ARC_REG_TIMERS_BCR, timer);
180 	cpu->extn.timer0 = timer.t0;
181 	cpu->extn.timer1 = timer.t1;
182 	cpu->extn.rtc = timer.rtc;
183 
184 	cpu->vec_base = read_aux_reg(AUX_INTR_VEC_BASE);
185 
186 	READ_BCR(ARC_REG_MUL_BCR, cpu->extn_mpy);
187 
188 	/* Read CCM BCRs for boot reporting even if not enabled in Kconfig */
189 	read_decode_ccm_bcr(cpu);
190 
191 	read_decode_mmu_bcr();
192 	read_decode_cache_bcr();
193 
194 	if (is_isa_arcompact()) {
195 		struct bcr_fp_arcompact sp, dp;
196 		struct bcr_bpu_arcompact bpu;
197 
198 		READ_BCR(ARC_REG_FP_BCR, sp);
199 		READ_BCR(ARC_REG_DPFP_BCR, dp);
200 		cpu->extn.fpu_sp = sp.ver ? 1 : 0;
201 		cpu->extn.fpu_dp = dp.ver ? 1 : 0;
202 
203 		READ_BCR(ARC_REG_BPU_BCR, bpu);
204 		cpu->bpu.ver = bpu.ver;
205 		cpu->bpu.full = bpu.fam ? 1 : 0;
206 		if (bpu.ent) {
207 			cpu->bpu.num_cache = 256 << (bpu.ent - 1);
208 			cpu->bpu.num_pred = 256 << (bpu.ent - 1);
209 		}
210 	} else {
211 		struct bcr_fp_arcv2 spdp;
212 		struct bcr_bpu_arcv2 bpu;
213 
214 		READ_BCR(ARC_REG_FP_V2_BCR, spdp);
215 		cpu->extn.fpu_sp = spdp.sp ? 1 : 0;
216 		cpu->extn.fpu_dp = spdp.dp ? 1 : 0;
217 
218 		READ_BCR(ARC_REG_BPU_BCR, bpu);
219 		cpu->bpu.ver = bpu.ver;
220 		cpu->bpu.full = bpu.ft;
221 		cpu->bpu.num_cache = 256 << bpu.bce;
222 		cpu->bpu.num_pred = 2048 << bpu.pte;
223 		cpu->bpu.ret_stk = 4 << bpu.rse;
224 
225 		/* if dual issue hardware, is it enabled ? */
226 		if (cpu->extn.dual) {
227 			unsigned int exec_ctrl;
228 
229 			READ_BCR(AUX_EXEC_CTRL, exec_ctrl);
230 			cpu->extn.dual_enb = !(exec_ctrl & 1);
231 		}
232 	}
233 
234 	READ_BCR(ARC_REG_AP_BCR, ap);
235 	if (ap.ver) {
236 		cpu->extn.ap_num = 2 << ap.num;
237 		cpu->extn.ap_full = !ap.min;
238 	}
239 
240 	READ_BCR(ARC_REG_SMART_BCR, bcr);
241 	cpu->extn.smart = bcr.ver ? 1 : 0;
242 
243 	READ_BCR(ARC_REG_RTT_BCR, bcr);
244 	cpu->extn.rtt = bcr.ver ? 1 : 0;
245 
246 	READ_BCR(ARC_REG_ISA_CFG_BCR, isa);
247 
248 	/* some hacks for lack of feature BCR info in old ARC700 cores */
249 	if (is_isa_arcompact()) {
250 		if (!isa.ver)	/* ISA BCR absent, use Kconfig info */
251 			cpu->isa.atomic = IS_ENABLED(CONFIG_ARC_HAS_LLSC);
252 		else {
253 			/* ARC700_BUILD only has 2 bits of isa info */
254 			struct bcr_generic bcr = *(struct bcr_generic *)&isa;
255 			cpu->isa.atomic = bcr.info & 1;
256 		}
257 
258 		cpu->isa.be = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
259 
260 		 /* there's no direct way to distinguish 750 vs. 770 */
261 		if (unlikely(cpu->core.family < 0x34 || cpu->mmu.ver < 3))
262 			cpu->name = "ARC750";
263 	} else {
264 		cpu->isa = isa;
265 	}
266 }
267 
268 static char *arc_cpu_mumbojumbo(int cpu_id, char *buf, int len)
269 {
270 	struct cpuinfo_arc *cpu = &cpuinfo_arc700[cpu_id];
271 	struct bcr_identity *core = &cpu->core;
272 	char mpy_opt[16];
273 	int n = 0;
274 
275 	FIX_PTR(cpu);
276 
277 	n += scnprintf(buf + n, len - n,
278 		       "\nIDENTITY\t: ARCVER [%#02x] ARCNUM [%#02x] CHIPID [%#4x]\n",
279 		       core->family, core->cpu_id, core->chip_id);
280 
281 	n += scnprintf(buf + n, len - n, "processor [%d]\t: %s %s (%s ISA) %s%s%s\n",
282 		       cpu_id, cpu->name, cpu->release,
283 		       is_isa_arcompact() ? "ARCompact" : "ARCv2",
284 		       IS_AVAIL1(cpu->isa.be, "[Big-Endian]"),
285 		       IS_AVAIL3(cpu->extn.dual, cpu->extn.dual_enb, " Dual-Issue "));
286 
287 	n += scnprintf(buf + n, len - n, "Timers\t\t: %s%s%s%s%s%s\nISA Extn\t: ",
288 		       IS_AVAIL1(cpu->extn.timer0, "Timer0 "),
289 		       IS_AVAIL1(cpu->extn.timer1, "Timer1 "),
290 		       IS_AVAIL2(cpu->extn.rtc, "RTC [UP 64-bit] ", CONFIG_ARC_TIMERS_64BIT),
291 		       IS_AVAIL2(cpu->extn.gfrc, "GFRC [SMP 64-bit] ", CONFIG_ARC_TIMERS_64BIT));
292 
293 	if (cpu->extn_mpy.ver) {
294 		if (is_isa_arcompact()) {
295 			scnprintf(mpy_opt, 16, "mpy");
296 		} else {
297 
298 			int opt = 2;	/* stock MPY/MPYH */
299 
300 			if (cpu->extn_mpy.dsp)	/* OPT 7-9 */
301 				opt = cpu->extn_mpy.dsp + 6;
302 
303 			scnprintf(mpy_opt, 16, "mpy[opt %d] ", opt);
304 		}
305 	}
306 
307 	n += scnprintf(buf + n, len - n, "%s%s%s%s%s%s%s%s\n",
308 		       IS_AVAIL2(cpu->isa.atomic, "atomic ", CONFIG_ARC_HAS_LLSC),
309 		       IS_AVAIL2(cpu->isa.ldd, "ll64 ", CONFIG_ARC_HAS_LL64),
310 		       IS_AVAIL2(cpu->isa.unalign, "unalign ", CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS),
311 		       IS_AVAIL1(cpu->extn_mpy.ver, mpy_opt),
312 		       IS_AVAIL1(cpu->isa.div_rem, "div_rem "));
313 
314 	if (cpu->bpu.ver) {
315 		n += scnprintf(buf + n, len - n,
316 			      "BPU\t\t: %s%s match, cache:%d, Predict Table:%d Return stk: %d",
317 			      IS_AVAIL1(cpu->bpu.full, "full"),
318 			      IS_AVAIL1(!cpu->bpu.full, "partial"),
319 			      cpu->bpu.num_cache, cpu->bpu.num_pred, cpu->bpu.ret_stk);
320 
321 		if (is_isa_arcv2()) {
322 			struct bcr_lpb lpb;
323 
324 			READ_BCR(ARC_REG_LPB_BUILD, lpb);
325 			if (lpb.ver) {
326 				unsigned int ctl;
327 				ctl = read_aux_reg(ARC_REG_LPB_CTRL);
328 
329 				n += scnprintf(buf + n, len - n, " Loop Buffer:%d %s",
330 					       lpb.entries,
331 					       IS_DISABLED_RUN(!ctl));
332 			}
333 		}
334 		n += scnprintf(buf + n, len - n, "\n");
335 	}
336 
337 	return buf;
338 }
339 
340 static char *arc_extn_mumbojumbo(int cpu_id, char *buf, int len)
341 {
342 	int n = 0;
343 	struct cpuinfo_arc *cpu = &cpuinfo_arc700[cpu_id];
344 
345 	FIX_PTR(cpu);
346 
347 	n += scnprintf(buf + n, len - n, "Vector Table\t: %#x\n", cpu->vec_base);
348 
349 	if (cpu->extn.fpu_sp || cpu->extn.fpu_dp)
350 		n += scnprintf(buf + n, len - n, "FPU\t\t: %s%s\n",
351 			       IS_AVAIL1(cpu->extn.fpu_sp, "SP "),
352 			       IS_AVAIL1(cpu->extn.fpu_dp, "DP "));
353 
354 	if (cpu->extn.ap_num | cpu->extn.smart | cpu->extn.rtt) {
355 		n += scnprintf(buf + n, len - n, "DEBUG\t\t: %s%s",
356 			       IS_AVAIL1(cpu->extn.smart, "smaRT "),
357 			       IS_AVAIL1(cpu->extn.rtt, "RTT "));
358 		if (cpu->extn.ap_num) {
359 			n += scnprintf(buf + n, len - n, "ActionPoint %d/%s",
360 				       cpu->extn.ap_num,
361 				       cpu->extn.ap_full ? "full":"min");
362 		}
363 		n += scnprintf(buf + n, len - n, "\n");
364 	}
365 
366 	if (cpu->dccm.sz || cpu->iccm.sz)
367 		n += scnprintf(buf + n, len - n, "Extn [CCM]\t: DCCM @ %x, %d KB / ICCM: @ %x, %d KB\n",
368 			       cpu->dccm.base_addr, TO_KB(cpu->dccm.sz),
369 			       cpu->iccm.base_addr, TO_KB(cpu->iccm.sz));
370 
371 	if (is_isa_arcv2()) {
372 
373 		/* Error Protection: ECC/Parity */
374 		struct bcr_erp erp;
375 		READ_BCR(ARC_REG_ERP_BUILD, erp);
376 
377 		if (erp.ver) {
378 			struct  ctl_erp ctl;
379 			READ_BCR(ARC_REG_ERP_CTRL, ctl);
380 
381 			/* inverted bits: 0 means enabled */
382 			n += scnprintf(buf + n, len - n, "Extn [ECC]\t: %s%s%s%s%s%s\n",
383 				IS_AVAIL3(erp.ic,  !ctl.dpi, "IC "),
384 				IS_AVAIL3(erp.dc,  !ctl.dpd, "DC "),
385 				IS_AVAIL3(erp.mmu, !ctl.mpd, "MMU "));
386 		}
387 	}
388 
389 	return buf;
390 }
391 
392 static void arc_chk_core_config(void)
393 {
394 	struct cpuinfo_arc *cpu = &cpuinfo_arc700[smp_processor_id()];
395 	int saved = 0, present = 0;
396 	char *opt_nm = NULL;
397 
398 	if (!cpu->extn.timer0)
399 		panic("Timer0 is not present!\n");
400 
401 	if (!cpu->extn.timer1)
402 		panic("Timer1 is not present!\n");
403 
404 #ifdef CONFIG_ARC_HAS_DCCM
405 	/*
406 	 * DCCM can be arbit placed in hardware.
407 	 * Make sure it's placement/sz matches what Linux is built with
408 	 */
409 	if ((unsigned int)__arc_dccm_base != cpu->dccm.base_addr)
410 		panic("Linux built with incorrect DCCM Base address\n");
411 
412 	if (CONFIG_ARC_DCCM_SZ != cpu->dccm.sz)
413 		panic("Linux built with incorrect DCCM Size\n");
414 #endif
415 
416 #ifdef CONFIG_ARC_HAS_ICCM
417 	if (CONFIG_ARC_ICCM_SZ != cpu->iccm.sz)
418 		panic("Linux built with incorrect ICCM Size\n");
419 #endif
420 
421 	/*
422 	 * FP hardware/software config sanity
423 	 * -If hardware present, kernel needs to save/restore FPU state
424 	 * -If not, it will crash trying to save/restore the non-existant regs
425 	 */
426 
427 	if (is_isa_arcompact()) {
428 		opt_nm = "CONFIG_ARC_FPU_SAVE_RESTORE";
429 		saved = IS_ENABLED(CONFIG_ARC_FPU_SAVE_RESTORE);
430 
431 		/* only DPDP checked since SP has no arch visible regs */
432 		present = cpu->extn.fpu_dp;
433 	} else {
434 		opt_nm = "CONFIG_ARC_HAS_ACCL_REGS";
435 		saved = IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS);
436 
437 		/* Accumulator Low:High pair (r58:59) present if DSP MPY or FPU */
438 		present = cpu->extn_mpy.dsp | cpu->extn.fpu_sp | cpu->extn.fpu_dp;
439 	}
440 
441 	if (present && !saved)
442 		pr_warn("Enable %s for working apps\n", opt_nm);
443 	else if (!present && saved)
444 		panic("Disable %s, hardware NOT present\n", opt_nm);
445 }
446 
447 /*
448  * Initialize and setup the processor core
449  * This is called by all the CPUs thus should not do special case stuff
450  *    such as only for boot CPU etc
451  */
452 
453 void setup_processor(void)
454 {
455 	char str[512];
456 	int cpu_id = smp_processor_id();
457 
458 	read_arc_build_cfg_regs();
459 	arc_init_IRQ();
460 
461 	pr_info("%s", arc_cpu_mumbojumbo(cpu_id, str, sizeof(str)));
462 
463 	arc_mmu_init();
464 	arc_cache_init();
465 
466 	pr_info("%s", arc_extn_mumbojumbo(cpu_id, str, sizeof(str)));
467 	pr_info("%s", arc_platform_smp_cpuinfo());
468 
469 	arc_chk_core_config();
470 }
471 
472 static inline bool uboot_arg_invalid(unsigned long addr)
473 {
474 	/*
475 	 * Check that it is a untranslated address (although MMU is not enabled
476 	 * yet, it being a high address ensures this is not by fluke)
477 	 */
478 	if (addr < PAGE_OFFSET)
479 		return true;
480 
481 	/* Check that address doesn't clobber resident kernel image */
482 	return addr >= (unsigned long)_stext && addr <= (unsigned long)_end;
483 }
484 
485 #define IGNORE_ARGS		"Ignore U-boot args: "
486 
487 /* uboot_tag values for U-boot - kernel ABI revision 0; see head.S */
488 #define UBOOT_TAG_NONE		0
489 #define UBOOT_TAG_CMDLINE	1
490 #define UBOOT_TAG_DTB		2
491 /* We always pass 0 as magic from U-boot */
492 #define UBOOT_MAGIC_VALUE	0
493 
494 void __init handle_uboot_args(void)
495 {
496 	bool use_embedded_dtb = true;
497 	bool append_cmdline = false;
498 
499 	/* check that we know this tag */
500 	if (uboot_tag != UBOOT_TAG_NONE &&
501 	    uboot_tag != UBOOT_TAG_CMDLINE &&
502 	    uboot_tag != UBOOT_TAG_DTB) {
503 		pr_warn(IGNORE_ARGS "invalid uboot tag: '%08x'\n", uboot_tag);
504 		goto ignore_uboot_args;
505 	}
506 
507 	if (uboot_magic != UBOOT_MAGIC_VALUE) {
508 		pr_warn(IGNORE_ARGS "non zero uboot magic\n");
509 		goto ignore_uboot_args;
510 	}
511 
512 	if (uboot_tag != UBOOT_TAG_NONE &&
513             uboot_arg_invalid((unsigned long)uboot_arg)) {
514 		pr_warn(IGNORE_ARGS "invalid uboot arg: '%px'\n", uboot_arg);
515 		goto ignore_uboot_args;
516 	}
517 
518 	/* see if U-boot passed an external Device Tree blob */
519 	if (uboot_tag == UBOOT_TAG_DTB) {
520 		machine_desc = setup_machine_fdt((void *)uboot_arg);
521 
522 		/* external Device Tree blob is invalid - use embedded one */
523 		use_embedded_dtb = !machine_desc;
524 	}
525 
526 	if (uboot_tag == UBOOT_TAG_CMDLINE)
527 		append_cmdline = true;
528 
529 ignore_uboot_args:
530 
531 	if (use_embedded_dtb) {
532 		machine_desc = setup_machine_fdt(__dtb_start);
533 		if (!machine_desc)
534 			panic("Embedded DT invalid\n");
535 	}
536 
537 	/*
538 	 * NOTE: @boot_command_line is populated by setup_machine_fdt() so this
539 	 * append processing can only happen after.
540 	 */
541 	if (append_cmdline) {
542 		/* Ensure a whitespace between the 2 cmdlines */
543 		strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
544 		strlcat(boot_command_line, uboot_arg, COMMAND_LINE_SIZE);
545 	}
546 }
547 
548 void __init setup_arch(char **cmdline_p)
549 {
550 	handle_uboot_args();
551 
552 	/* Save unparsed command line copy for /proc/cmdline */
553 	*cmdline_p = boot_command_line;
554 
555 	/* To force early parsing of things like mem=xxx */
556 	parse_early_param();
557 
558 	/* Platform/board specific: e.g. early console registration */
559 	if (machine_desc->init_early)
560 		machine_desc->init_early();
561 
562 	smp_init_cpus();
563 
564 	setup_processor();
565 	setup_arch_memory();
566 
567 	/* copy flat DT out of .init and then unflatten it */
568 	unflatten_and_copy_device_tree();
569 
570 	/* Can be issue if someone passes cmd line arg "ro"
571 	 * But that is unlikely so keeping it as it is
572 	 */
573 	root_mountflags &= ~MS_RDONLY;
574 
575 #if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
576 	conswitchp = &dummy_con;
577 #endif
578 
579 	arc_unwind_init();
580 }
581 
582 /*
583  * Called from start_kernel() - boot CPU only
584  */
585 void __init time_init(void)
586 {
587 	of_clk_init(NULL);
588 	timer_probe();
589 }
590 
591 static int __init customize_machine(void)
592 {
593 	if (machine_desc->init_machine)
594 		machine_desc->init_machine();
595 
596 	return 0;
597 }
598 arch_initcall(customize_machine);
599 
600 static int __init init_late_machine(void)
601 {
602 	if (machine_desc->init_late)
603 		machine_desc->init_late();
604 
605 	return 0;
606 }
607 late_initcall(init_late_machine);
608 /*
609  *  Get CPU information for use by the procfs.
610  */
611 
612 #define cpu_to_ptr(c)	((void *)(0xFFFF0000 | (unsigned int)(c)))
613 #define ptr_to_cpu(p)	(~0xFFFF0000UL & (unsigned int)(p))
614 
615 static int show_cpuinfo(struct seq_file *m, void *v)
616 {
617 	char *str;
618 	int cpu_id = ptr_to_cpu(v);
619 	struct device *cpu_dev = get_cpu_device(cpu_id);
620 	struct clk *cpu_clk;
621 	unsigned long freq = 0;
622 
623 	if (!cpu_online(cpu_id)) {
624 		seq_printf(m, "processor [%d]\t: Offline\n", cpu_id);
625 		goto done;
626 	}
627 
628 	str = (char *)__get_free_page(GFP_KERNEL);
629 	if (!str)
630 		goto done;
631 
632 	seq_printf(m, arc_cpu_mumbojumbo(cpu_id, str, PAGE_SIZE));
633 
634 	cpu_clk = clk_get(cpu_dev, NULL);
635 	if (IS_ERR(cpu_clk)) {
636 		seq_printf(m, "CPU speed \t: Cannot get clock for processor [%d]\n",
637 			   cpu_id);
638 	} else {
639 		freq = clk_get_rate(cpu_clk);
640 	}
641 	if (freq)
642 		seq_printf(m, "CPU speed\t: %lu.%02lu Mhz\n",
643 			   freq / 1000000, (freq / 10000) % 100);
644 
645 	seq_printf(m, "Bogo MIPS\t: %lu.%02lu\n",
646 		   loops_per_jiffy / (500000 / HZ),
647 		   (loops_per_jiffy / (5000 / HZ)) % 100);
648 
649 	seq_printf(m, arc_mmu_mumbojumbo(cpu_id, str, PAGE_SIZE));
650 	seq_printf(m, arc_cache_mumbojumbo(cpu_id, str, PAGE_SIZE));
651 	seq_printf(m, arc_extn_mumbojumbo(cpu_id, str, PAGE_SIZE));
652 	seq_printf(m, arc_platform_smp_cpuinfo());
653 
654 	free_page((unsigned long)str);
655 done:
656 	seq_printf(m, "\n");
657 
658 	return 0;
659 }
660 
661 static void *c_start(struct seq_file *m, loff_t *pos)
662 {
663 	/*
664 	 * Callback returns cpu-id to iterator for show routine, NULL to stop.
665 	 * However since NULL is also a valid cpu-id (0), we use a round-about
666 	 * way to pass it w/o having to kmalloc/free a 2 byte string.
667 	 * Encode cpu-id as 0xFFcccc, which is decoded by show routine.
668 	 */
669 	return *pos < nr_cpu_ids ? cpu_to_ptr(*pos) : NULL;
670 }
671 
672 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
673 {
674 	++*pos;
675 	return c_start(m, pos);
676 }
677 
678 static void c_stop(struct seq_file *m, void *v)
679 {
680 }
681 
682 const struct seq_operations cpuinfo_op = {
683 	.start	= c_start,
684 	.next	= c_next,
685 	.stop	= c_stop,
686 	.show	= show_cpuinfo
687 };
688 
689 static DEFINE_PER_CPU(struct cpu, cpu_topology);
690 
691 static int __init topology_init(void)
692 {
693 	int cpu;
694 
695 	for_each_present_cpu(cpu)
696 	    register_cpu(&per_cpu(cpu_topology, cpu), cpu);
697 
698 	return 0;
699 }
700 
701 subsys_initcall(topology_init);
702