xref: /openbmc/u-boot/arch/x86/cpu/cpu.c (revision fea7f3aa)
1 /*
2  * (C) Copyright 2008-2011
3  * Graeme Russ, <graeme.russ@gmail.com>
4  *
5  * (C) Copyright 2002
6  * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
7  *
8  * (C) Copyright 2002
9  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
10  * Marius Groeger <mgroeger@sysgo.de>
11  *
12  * (C) Copyright 2002
13  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
14  * Alex Zuepke <azu@sysgo.de>
15  *
16  * Part of this file is adapted from coreboot
17  * src/arch/x86/lib/cpu.c
18  *
19  * SPDX-License-Identifier:	GPL-2.0+
20  */
21 
22 #include <common.h>
23 #include <command.h>
24 #include <dm.h>
25 #include <errno.h>
26 #include <malloc.h>
27 #include <asm/control_regs.h>
28 #include <asm/cpu.h>
29 #include <asm/lapic.h>
30 #include <asm/mp.h>
31 #include <asm/msr.h>
32 #include <asm/mtrr.h>
33 #include <asm/post.h>
34 #include <asm/processor.h>
35 #include <asm/processor-flags.h>
36 #include <asm/interrupt.h>
37 #include <asm/tables.h>
38 #include <linux/compiler.h>
39 
40 DECLARE_GLOBAL_DATA_PTR;
41 
42 /*
43  * Constructor for a conventional segment GDT (or LDT) entry
44  * This is a macro so it can be used in initialisers
45  */
46 #define GDT_ENTRY(flags, base, limit)			\
47 	((((base)  & 0xff000000ULL) << (56-24)) |	\
48 	 (((flags) & 0x0000f0ffULL) << 40) |		\
49 	 (((limit) & 0x000f0000ULL) << (48-16)) |	\
50 	 (((base)  & 0x00ffffffULL) << 16) |		\
51 	 (((limit) & 0x0000ffffULL)))
52 
53 struct gdt_ptr {
54 	u16 len;
55 	u32 ptr;
56 } __packed;
57 
58 struct cpu_device_id {
59 	unsigned vendor;
60 	unsigned device;
61 };
62 
63 struct cpuinfo_x86 {
64 	uint8_t x86;            /* CPU family */
65 	uint8_t x86_vendor;     /* CPU vendor */
66 	uint8_t x86_model;
67 	uint8_t x86_mask;
68 };
69 
70 /*
71  * List of cpu vendor strings along with their normalized
72  * id values.
73  */
74 static struct {
75 	int vendor;
76 	const char *name;
77 } x86_vendors[] = {
78 	{ X86_VENDOR_INTEL,     "GenuineIntel", },
79 	{ X86_VENDOR_CYRIX,     "CyrixInstead", },
80 	{ X86_VENDOR_AMD,       "AuthenticAMD", },
81 	{ X86_VENDOR_UMC,       "UMC UMC UMC ", },
82 	{ X86_VENDOR_NEXGEN,    "NexGenDriven", },
83 	{ X86_VENDOR_CENTAUR,   "CentaurHauls", },
84 	{ X86_VENDOR_RISE,      "RiseRiseRise", },
85 	{ X86_VENDOR_TRANSMETA, "GenuineTMx86", },
86 	{ X86_VENDOR_TRANSMETA, "TransmetaCPU", },
87 	{ X86_VENDOR_NSC,       "Geode by NSC", },
88 	{ X86_VENDOR_SIS,       "SiS SiS SiS ", },
89 };
90 
91 static const char *const x86_vendor_name[] = {
92 	[X86_VENDOR_INTEL]     = "Intel",
93 	[X86_VENDOR_CYRIX]     = "Cyrix",
94 	[X86_VENDOR_AMD]       = "AMD",
95 	[X86_VENDOR_UMC]       = "UMC",
96 	[X86_VENDOR_NEXGEN]    = "NexGen",
97 	[X86_VENDOR_CENTAUR]   = "Centaur",
98 	[X86_VENDOR_RISE]      = "Rise",
99 	[X86_VENDOR_TRANSMETA] = "Transmeta",
100 	[X86_VENDOR_NSC]       = "NSC",
101 	[X86_VENDOR_SIS]       = "SiS",
102 };
103 
104 static void load_ds(u32 segment)
105 {
106 	asm volatile("movl %0, %%ds" : : "r" (segment * X86_GDT_ENTRY_SIZE));
107 }
108 
109 static void load_es(u32 segment)
110 {
111 	asm volatile("movl %0, %%es" : : "r" (segment * X86_GDT_ENTRY_SIZE));
112 }
113 
114 static void load_fs(u32 segment)
115 {
116 	asm volatile("movl %0, %%fs" : : "r" (segment * X86_GDT_ENTRY_SIZE));
117 }
118 
119 static void load_gs(u32 segment)
120 {
121 	asm volatile("movl %0, %%gs" : : "r" (segment * X86_GDT_ENTRY_SIZE));
122 }
123 
124 static void load_ss(u32 segment)
125 {
126 	asm volatile("movl %0, %%ss" : : "r" (segment * X86_GDT_ENTRY_SIZE));
127 }
128 
129 static void load_gdt(const u64 *boot_gdt, u16 num_entries)
130 {
131 	struct gdt_ptr gdt;
132 
133 	gdt.len = (num_entries * X86_GDT_ENTRY_SIZE) - 1;
134 	gdt.ptr = (u32)boot_gdt;
135 
136 	asm volatile("lgdtl %0\n" : : "m" (gdt));
137 }
138 
139 void arch_setup_gd(gd_t *new_gd)
140 {
141 	u64 *gdt_addr;
142 
143 	gdt_addr = new_gd->arch.gdt;
144 
145 	/*
146 	 * CS: code, read/execute, 4 GB, base 0
147 	 *
148 	 * Some OS (like VxWorks) requires GDT entry 1 to be the 32-bit CS
149 	 */
150 	gdt_addr[X86_GDT_ENTRY_UNUSED] = GDT_ENTRY(0xc09b, 0, 0xfffff);
151 	gdt_addr[X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff);
152 
153 	/* DS: data, read/write, 4 GB, base 0 */
154 	gdt_addr[X86_GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff);
155 
156 	/* FS: data, read/write, 4 GB, base (Global Data Pointer) */
157 	new_gd->arch.gd_addr = new_gd;
158 	gdt_addr[X86_GDT_ENTRY_32BIT_FS] = GDT_ENTRY(0xc093,
159 		     (ulong)&new_gd->arch.gd_addr, 0xfffff);
160 
161 	/* 16-bit CS: code, read/execute, 64 kB, base 0 */
162 	gdt_addr[X86_GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x009b, 0, 0x0ffff);
163 
164 	/* 16-bit DS: data, read/write, 64 kB, base 0 */
165 	gdt_addr[X86_GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x0093, 0, 0x0ffff);
166 
167 	gdt_addr[X86_GDT_ENTRY_16BIT_FLAT_CS] = GDT_ENTRY(0x809b, 0, 0xfffff);
168 	gdt_addr[X86_GDT_ENTRY_16BIT_FLAT_DS] = GDT_ENTRY(0x8093, 0, 0xfffff);
169 
170 	load_gdt(gdt_addr, X86_GDT_NUM_ENTRIES);
171 	load_ds(X86_GDT_ENTRY_32BIT_DS);
172 	load_es(X86_GDT_ENTRY_32BIT_DS);
173 	load_gs(X86_GDT_ENTRY_32BIT_DS);
174 	load_ss(X86_GDT_ENTRY_32BIT_DS);
175 	load_fs(X86_GDT_ENTRY_32BIT_FS);
176 }
177 
178 #ifdef CONFIG_HAVE_FSP
179 /*
180  * Setup FSP execution environment GDT
181  *
182  * Per Intel FSP external architecture specification, before calling any FSP
183  * APIs, we need make sure the system is in flat 32-bit mode and both the code
184  * and data selectors should have full 4GB access range. Here we reuse the one
185  * we used in arch/x86/cpu/start16.S, and reload the segement registers.
186  */
187 void setup_fsp_gdt(void)
188 {
189 	load_gdt((const u64 *)(gdt_rom + CONFIG_RESET_SEG_START), 4);
190 	load_ds(X86_GDT_ENTRY_32BIT_DS);
191 	load_ss(X86_GDT_ENTRY_32BIT_DS);
192 	load_es(X86_GDT_ENTRY_32BIT_DS);
193 	load_fs(X86_GDT_ENTRY_32BIT_DS);
194 	load_gs(X86_GDT_ENTRY_32BIT_DS);
195 }
196 #endif
197 
198 int __weak x86_cleanup_before_linux(void)
199 {
200 #ifdef CONFIG_BOOTSTAGE_STASH
201 	bootstage_stash((void *)CONFIG_BOOTSTAGE_STASH_ADDR,
202 			CONFIG_BOOTSTAGE_STASH_SIZE);
203 #endif
204 
205 	return 0;
206 }
207 
208 /*
209  * Cyrix CPUs without cpuid or with cpuid not yet enabled can be detected
210  * by the fact that they preserve the flags across the division of 5/2.
211  * PII and PPro exhibit this behavior too, but they have cpuid available.
212  */
213 
214 /*
215  * Perform the Cyrix 5/2 test. A Cyrix won't change
216  * the flags, while other 486 chips will.
217  */
218 static inline int test_cyrix_52div(void)
219 {
220 	unsigned int test;
221 
222 	__asm__ __volatile__(
223 	     "sahf\n\t"		/* clear flags (%eax = 0x0005) */
224 	     "div %b2\n\t"	/* divide 5 by 2 */
225 	     "lahf"		/* store flags into %ah */
226 	     : "=a" (test)
227 	     : "0" (5), "q" (2)
228 	     : "cc");
229 
230 	/* AH is 0x02 on Cyrix after the divide.. */
231 	return (unsigned char) (test >> 8) == 0x02;
232 }
233 
234 /*
235  *	Detect a NexGen CPU running without BIOS hypercode new enough
236  *	to have CPUID. (Thanks to Herbert Oppmann)
237  */
238 
239 static int deep_magic_nexgen_probe(void)
240 {
241 	int ret;
242 
243 	__asm__ __volatile__ (
244 		"	movw	$0x5555, %%ax\n"
245 		"	xorw	%%dx,%%dx\n"
246 		"	movw	$2, %%cx\n"
247 		"	divw	%%cx\n"
248 		"	movl	$0, %%eax\n"
249 		"	jnz	1f\n"
250 		"	movl	$1, %%eax\n"
251 		"1:\n"
252 		: "=a" (ret) : : "cx", "dx");
253 	return  ret;
254 }
255 
256 static bool has_cpuid(void)
257 {
258 	return flag_is_changeable_p(X86_EFLAGS_ID);
259 }
260 
261 static bool has_mtrr(void)
262 {
263 	return cpuid_edx(0x00000001) & (1 << 12) ? true : false;
264 }
265 
266 static int build_vendor_name(char *vendor_name)
267 {
268 	struct cpuid_result result;
269 	result = cpuid(0x00000000);
270 	unsigned int *name_as_ints = (unsigned int *)vendor_name;
271 
272 	name_as_ints[0] = result.ebx;
273 	name_as_ints[1] = result.edx;
274 	name_as_ints[2] = result.ecx;
275 
276 	return result.eax;
277 }
278 
279 static void identify_cpu(struct cpu_device_id *cpu)
280 {
281 	char vendor_name[16];
282 	int i;
283 
284 	vendor_name[0] = '\0'; /* Unset */
285 	cpu->device = 0; /* fix gcc 4.4.4 warning */
286 
287 	/* Find the id and vendor_name */
288 	if (!has_cpuid()) {
289 		/* Its a 486 if we can modify the AC flag */
290 		if (flag_is_changeable_p(X86_EFLAGS_AC))
291 			cpu->device = 0x00000400; /* 486 */
292 		else
293 			cpu->device = 0x00000300; /* 386 */
294 		if ((cpu->device == 0x00000400) && test_cyrix_52div()) {
295 			memcpy(vendor_name, "CyrixInstead", 13);
296 			/* If we ever care we can enable cpuid here */
297 		}
298 		/* Detect NexGen with old hypercode */
299 		else if (deep_magic_nexgen_probe())
300 			memcpy(vendor_name, "NexGenDriven", 13);
301 	}
302 	if (has_cpuid()) {
303 		int  cpuid_level;
304 
305 		cpuid_level = build_vendor_name(vendor_name);
306 		vendor_name[12] = '\0';
307 
308 		/* Intel-defined flags: level 0x00000001 */
309 		if (cpuid_level >= 0x00000001) {
310 			cpu->device = cpuid_eax(0x00000001);
311 		} else {
312 			/* Have CPUID level 0 only unheard of */
313 			cpu->device = 0x00000400;
314 		}
315 	}
316 	cpu->vendor = X86_VENDOR_UNKNOWN;
317 	for (i = 0; i < ARRAY_SIZE(x86_vendors); i++) {
318 		if (memcmp(vendor_name, x86_vendors[i].name, 12) == 0) {
319 			cpu->vendor = x86_vendors[i].vendor;
320 			break;
321 		}
322 	}
323 }
324 
325 static inline void get_fms(struct cpuinfo_x86 *c, uint32_t tfms)
326 {
327 	c->x86 = (tfms >> 8) & 0xf;
328 	c->x86_model = (tfms >> 4) & 0xf;
329 	c->x86_mask = tfms & 0xf;
330 	if (c->x86 == 0xf)
331 		c->x86 += (tfms >> 20) & 0xff;
332 	if (c->x86 >= 0x6)
333 		c->x86_model += ((tfms >> 16) & 0xF) << 4;
334 }
335 
336 int x86_cpu_init_f(void)
337 {
338 	const u32 em_rst = ~X86_CR0_EM;
339 	const u32 mp_ne_set = X86_CR0_MP | X86_CR0_NE;
340 
341 	if (ll_boot_init()) {
342 		/* initialize FPU, reset EM, set MP and NE */
343 		asm ("fninit\n" \
344 		"movl %%cr0, %%eax\n" \
345 		"andl %0, %%eax\n" \
346 		"orl  %1, %%eax\n" \
347 		"movl %%eax, %%cr0\n" \
348 		: : "i" (em_rst), "i" (mp_ne_set) : "eax");
349 	}
350 
351 	/* identify CPU via cpuid and store the decoded info into gd->arch */
352 	if (has_cpuid()) {
353 		struct cpu_device_id cpu;
354 		struct cpuinfo_x86 c;
355 
356 		identify_cpu(&cpu);
357 		get_fms(&c, cpu.device);
358 		gd->arch.x86 = c.x86;
359 		gd->arch.x86_vendor = cpu.vendor;
360 		gd->arch.x86_model = c.x86_model;
361 		gd->arch.x86_mask = c.x86_mask;
362 		gd->arch.x86_device = cpu.device;
363 
364 		gd->arch.has_mtrr = has_mtrr();
365 	}
366 	/* Don't allow PCI region 3 to use memory in the 2-4GB memory hole */
367 	gd->pci_ram_top = 0x80000000U;
368 
369 	/* Configure fixed range MTRRs for some legacy regions */
370 	if (gd->arch.has_mtrr) {
371 		u64 mtrr_cap;
372 
373 		mtrr_cap = native_read_msr(MTRR_CAP_MSR);
374 		if (mtrr_cap & MTRR_CAP_FIX) {
375 			/* Mark the VGA RAM area as uncacheable */
376 			native_write_msr(MTRR_FIX_16K_A0000_MSR,
377 					 MTRR_FIX_TYPE(MTRR_TYPE_UNCACHEABLE),
378 					 MTRR_FIX_TYPE(MTRR_TYPE_UNCACHEABLE));
379 
380 			/*
381 			 * Mark the PCI ROM area as cacheable to improve ROM
382 			 * execution performance.
383 			 */
384 			native_write_msr(MTRR_FIX_4K_C0000_MSR,
385 					 MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
386 					 MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
387 			native_write_msr(MTRR_FIX_4K_C8000_MSR,
388 					 MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
389 					 MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
390 			native_write_msr(MTRR_FIX_4K_D0000_MSR,
391 					 MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
392 					 MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
393 			native_write_msr(MTRR_FIX_4K_D8000_MSR,
394 					 MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
395 					 MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
396 
397 			/* Enable the fixed range MTRRs */
398 			msr_setbits_64(MTRR_DEF_TYPE_MSR, MTRR_DEF_TYPE_FIX_EN);
399 		}
400 	}
401 
402 	return 0;
403 }
404 
405 void x86_enable_caches(void)
406 {
407 	unsigned long cr0;
408 
409 	cr0 = read_cr0();
410 	cr0 &= ~(X86_CR0_NW | X86_CR0_CD);
411 	write_cr0(cr0);
412 	wbinvd();
413 }
414 void enable_caches(void) __attribute__((weak, alias("x86_enable_caches")));
415 
416 void x86_disable_caches(void)
417 {
418 	unsigned long cr0;
419 
420 	cr0 = read_cr0();
421 	cr0 |= X86_CR0_NW | X86_CR0_CD;
422 	wbinvd();
423 	write_cr0(cr0);
424 	wbinvd();
425 }
426 void disable_caches(void) __attribute__((weak, alias("x86_disable_caches")));
427 
428 int x86_init_cache(void)
429 {
430 	enable_caches();
431 
432 	return 0;
433 }
434 int init_cache(void) __attribute__((weak, alias("x86_init_cache")));
435 
436 int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
437 {
438 	printf("resetting ...\n");
439 
440 	/* wait 50 ms */
441 	udelay(50000);
442 	disable_interrupts();
443 	reset_cpu(0);
444 
445 	/*NOTREACHED*/
446 	return 0;
447 }
448 
449 void  flush_cache(unsigned long dummy1, unsigned long dummy2)
450 {
451 	asm("wbinvd\n");
452 }
453 
454 __weak void reset_cpu(ulong addr)
455 {
456 	/* Do a hard reset through the chipset's reset control register */
457 	outb(SYS_RST | RST_CPU, PORT_RESET);
458 	for (;;)
459 		cpu_hlt();
460 }
461 
462 void x86_full_reset(void)
463 {
464 	outb(FULL_RST | SYS_RST | RST_CPU, PORT_RESET);
465 }
466 
467 int dcache_status(void)
468 {
469 	return !(read_cr0() & X86_CR0_CD);
470 }
471 
472 /* Define these functions to allow ehch-hcd to function */
473 void flush_dcache_range(unsigned long start, unsigned long stop)
474 {
475 }
476 
477 void invalidate_dcache_range(unsigned long start, unsigned long stop)
478 {
479 }
480 
481 void dcache_enable(void)
482 {
483 	enable_caches();
484 }
485 
486 void dcache_disable(void)
487 {
488 	disable_caches();
489 }
490 
491 void icache_enable(void)
492 {
493 }
494 
495 void icache_disable(void)
496 {
497 }
498 
499 int icache_status(void)
500 {
501 	return 1;
502 }
503 
504 void cpu_enable_paging_pae(ulong cr3)
505 {
506 	__asm__ __volatile__(
507 		/* Load the page table address */
508 		"movl	%0, %%cr3\n"
509 		/* Enable pae */
510 		"movl	%%cr4, %%eax\n"
511 		"orl	$0x00000020, %%eax\n"
512 		"movl	%%eax, %%cr4\n"
513 		/* Enable paging */
514 		"movl	%%cr0, %%eax\n"
515 		"orl	$0x80000000, %%eax\n"
516 		"movl	%%eax, %%cr0\n"
517 		:
518 		: "r" (cr3)
519 		: "eax");
520 }
521 
522 void cpu_disable_paging_pae(void)
523 {
524 	/* Turn off paging */
525 	__asm__ __volatile__ (
526 		/* Disable paging */
527 		"movl	%%cr0, %%eax\n"
528 		"andl	$0x7fffffff, %%eax\n"
529 		"movl	%%eax, %%cr0\n"
530 		/* Disable pae */
531 		"movl	%%cr4, %%eax\n"
532 		"andl	$0xffffffdf, %%eax\n"
533 		"movl	%%eax, %%cr4\n"
534 		:
535 		:
536 		: "eax");
537 }
538 
539 static bool can_detect_long_mode(void)
540 {
541 	return cpuid_eax(0x80000000) > 0x80000000UL;
542 }
543 
544 static bool has_long_mode(void)
545 {
546 	return cpuid_edx(0x80000001) & (1 << 29) ? true : false;
547 }
548 
549 int cpu_has_64bit(void)
550 {
551 	return has_cpuid() && can_detect_long_mode() &&
552 		has_long_mode();
553 }
554 
555 const char *cpu_vendor_name(int vendor)
556 {
557 	const char *name;
558 	name = "<invalid cpu vendor>";
559 	if ((vendor < (ARRAY_SIZE(x86_vendor_name))) &&
560 	    (x86_vendor_name[vendor] != 0))
561 		name = x86_vendor_name[vendor];
562 
563 	return name;
564 }
565 
566 char *cpu_get_name(char *name)
567 {
568 	unsigned int *name_as_ints = (unsigned int *)name;
569 	struct cpuid_result regs;
570 	char *ptr;
571 	int i;
572 
573 	/* This bit adds up to 48 bytes */
574 	for (i = 0; i < 3; i++) {
575 		regs = cpuid(0x80000002 + i);
576 		name_as_ints[i * 4 + 0] = regs.eax;
577 		name_as_ints[i * 4 + 1] = regs.ebx;
578 		name_as_ints[i * 4 + 2] = regs.ecx;
579 		name_as_ints[i * 4 + 3] = regs.edx;
580 	}
581 	name[CPU_MAX_NAME_LEN - 1] = '\0';
582 
583 	/* Skip leading spaces. */
584 	ptr = name;
585 	while (*ptr == ' ')
586 		ptr++;
587 
588 	return ptr;
589 }
590 
591 int default_print_cpuinfo(void)
592 {
593 	printf("CPU: %s, vendor %s, device %xh\n",
594 	       cpu_has_64bit() ? "x86_64" : "x86",
595 	       cpu_vendor_name(gd->arch.x86_vendor), gd->arch.x86_device);
596 
597 	return 0;
598 }
599 
600 #define PAGETABLE_SIZE		(6 * 4096)
601 
602 /**
603  * build_pagetable() - build a flat 4GiB page table structure for 64-bti mode
604  *
605  * @pgtable: Pointer to a 24iKB block of memory
606  */
607 static void build_pagetable(uint32_t *pgtable)
608 {
609 	uint i;
610 
611 	memset(pgtable, '\0', PAGETABLE_SIZE);
612 
613 	/* Level 4 needs a single entry */
614 	pgtable[0] = (uint32_t)&pgtable[1024] + 7;
615 
616 	/* Level 3 has one 64-bit entry for each GiB of memory */
617 	for (i = 0; i < 4; i++) {
618 		pgtable[1024 + i * 2] = (uint32_t)&pgtable[2048] +
619 							0x1000 * i + 7;
620 	}
621 
622 	/* Level 2 has 2048 64-bit entries, each repesenting 2MiB */
623 	for (i = 0; i < 2048; i++)
624 		pgtable[2048 + i * 2] = 0x183 + (i << 21UL);
625 }
626 
627 int cpu_jump_to_64bit(ulong setup_base, ulong target)
628 {
629 	uint32_t *pgtable;
630 
631 	pgtable = memalign(4096, PAGETABLE_SIZE);
632 	if (!pgtable)
633 		return -ENOMEM;
634 
635 	build_pagetable(pgtable);
636 	cpu_call64((ulong)pgtable, setup_base, target);
637 	free(pgtable);
638 
639 	return -EFAULT;
640 }
641 
642 void show_boot_progress(int val)
643 {
644 #if MIN_PORT80_KCLOCKS_DELAY
645 	/*
646 	 * Scale the time counter reading to avoid using 64 bit arithmetics.
647 	 * Can't use get_timer() here becuase it could be not yet
648 	 * initialized or even implemented.
649 	 */
650 	if (!gd->arch.tsc_prev) {
651 		gd->arch.tsc_base_kclocks = rdtsc() / 1000;
652 		gd->arch.tsc_prev = 0;
653 	} else {
654 		uint32_t now;
655 
656 		do {
657 			now = rdtsc() / 1000 - gd->arch.tsc_base_kclocks;
658 		} while (now < (gd->arch.tsc_prev + MIN_PORT80_KCLOCKS_DELAY));
659 		gd->arch.tsc_prev = now;
660 	}
661 #endif
662 	outb(val, POST_PORT);
663 }
664 
665 #ifndef CONFIG_SYS_COREBOOT
666 int last_stage_init(void)
667 {
668 	write_tables();
669 
670 	return 0;
671 }
672 #endif
673 
674 #ifdef CONFIG_SMP
675 static int enable_smis(struct udevice *cpu, void *unused)
676 {
677 	return 0;
678 }
679 
680 static struct mp_flight_record mp_steps[] = {
681 	MP_FR_BLOCK_APS(mp_init_cpu, NULL, mp_init_cpu, NULL),
682 	/* Wait for APs to finish initialization before proceeding */
683 	MP_FR_BLOCK_APS(NULL, NULL, enable_smis, NULL),
684 };
685 
686 static int x86_mp_init(void)
687 {
688 	struct mp_params mp_params;
689 
690 	mp_params.parallel_microcode_load = 0,
691 	mp_params.flight_plan = &mp_steps[0];
692 	mp_params.num_records = ARRAY_SIZE(mp_steps);
693 	mp_params.microcode_pointer = 0;
694 
695 	if (mp_init(&mp_params)) {
696 		printf("Warning: MP init failure\n");
697 		return -EIO;
698 	}
699 
700 	return 0;
701 }
702 #endif
703 
704 __weak int x86_init_cpus(void)
705 {
706 #ifdef CONFIG_SMP
707 	debug("Init additional CPUs\n");
708 	x86_mp_init();
709 #else
710 	struct udevice *dev;
711 
712 	/*
713 	 * This causes the cpu-x86 driver to be probed.
714 	 * We don't check return value here as we want to allow boards
715 	 * which have not been converted to use cpu uclass driver to boot.
716 	 */
717 	uclass_first_device(UCLASS_CPU, &dev);
718 #endif
719 
720 	return 0;
721 }
722 
723 int cpu_init_r(void)
724 {
725 	if (ll_boot_init())
726 		return x86_init_cpus();
727 
728 	return 0;
729 }
730