xref: /openbmc/u-boot/arch/x86/cpu/cpu.c (revision 002610f6)
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 <cpu.h>
25 #include <dm.h>
26 #include <errno.h>
27 #include <malloc.h>
28 #include <asm/control_regs.h>
29 #include <asm/cpu.h>
30 #include <asm/post.h>
31 #include <asm/processor.h>
32 #include <asm/processor-flags.h>
33 #include <asm/interrupt.h>
34 #include <asm/tables.h>
35 #include <linux/compiler.h>
36 
37 DECLARE_GLOBAL_DATA_PTR;
38 
39 /*
40  * Constructor for a conventional segment GDT (or LDT) entry
41  * This is a macro so it can be used in initialisers
42  */
43 #define GDT_ENTRY(flags, base, limit)			\
44 	((((base)  & 0xff000000ULL) << (56-24)) |	\
45 	 (((flags) & 0x0000f0ffULL) << 40) |		\
46 	 (((limit) & 0x000f0000ULL) << (48-16)) |	\
47 	 (((base)  & 0x00ffffffULL) << 16) |		\
48 	 (((limit) & 0x0000ffffULL)))
49 
50 struct gdt_ptr {
51 	u16 len;
52 	u32 ptr;
53 } __packed;
54 
55 struct cpu_device_id {
56 	unsigned vendor;
57 	unsigned device;
58 };
59 
60 struct cpuinfo_x86 {
61 	uint8_t x86;            /* CPU family */
62 	uint8_t x86_vendor;     /* CPU vendor */
63 	uint8_t x86_model;
64 	uint8_t x86_mask;
65 };
66 
67 /*
68  * List of cpu vendor strings along with their normalized
69  * id values.
70  */
71 static struct {
72 	int vendor;
73 	const char *name;
74 } x86_vendors[] = {
75 	{ X86_VENDOR_INTEL,     "GenuineIntel", },
76 	{ X86_VENDOR_CYRIX,     "CyrixInstead", },
77 	{ X86_VENDOR_AMD,       "AuthenticAMD", },
78 	{ X86_VENDOR_UMC,       "UMC UMC UMC ", },
79 	{ X86_VENDOR_NEXGEN,    "NexGenDriven", },
80 	{ X86_VENDOR_CENTAUR,   "CentaurHauls", },
81 	{ X86_VENDOR_RISE,      "RiseRiseRise", },
82 	{ X86_VENDOR_TRANSMETA, "GenuineTMx86", },
83 	{ X86_VENDOR_TRANSMETA, "TransmetaCPU", },
84 	{ X86_VENDOR_NSC,       "Geode by NSC", },
85 	{ X86_VENDOR_SIS,       "SiS SiS SiS ", },
86 };
87 
88 static const char *const x86_vendor_name[] = {
89 	[X86_VENDOR_INTEL]     = "Intel",
90 	[X86_VENDOR_CYRIX]     = "Cyrix",
91 	[X86_VENDOR_AMD]       = "AMD",
92 	[X86_VENDOR_UMC]       = "UMC",
93 	[X86_VENDOR_NEXGEN]    = "NexGen",
94 	[X86_VENDOR_CENTAUR]   = "Centaur",
95 	[X86_VENDOR_RISE]      = "Rise",
96 	[X86_VENDOR_TRANSMETA] = "Transmeta",
97 	[X86_VENDOR_NSC]       = "NSC",
98 	[X86_VENDOR_SIS]       = "SiS",
99 };
100 
101 static void load_ds(u32 segment)
102 {
103 	asm volatile("movl %0, %%ds" : : "r" (segment * X86_GDT_ENTRY_SIZE));
104 }
105 
106 static void load_es(u32 segment)
107 {
108 	asm volatile("movl %0, %%es" : : "r" (segment * X86_GDT_ENTRY_SIZE));
109 }
110 
111 static void load_fs(u32 segment)
112 {
113 	asm volatile("movl %0, %%fs" : : "r" (segment * X86_GDT_ENTRY_SIZE));
114 }
115 
116 static void load_gs(u32 segment)
117 {
118 	asm volatile("movl %0, %%gs" : : "r" (segment * X86_GDT_ENTRY_SIZE));
119 }
120 
121 static void load_ss(u32 segment)
122 {
123 	asm volatile("movl %0, %%ss" : : "r" (segment * X86_GDT_ENTRY_SIZE));
124 }
125 
126 static void load_gdt(const u64 *boot_gdt, u16 num_entries)
127 {
128 	struct gdt_ptr gdt;
129 
130 	gdt.len = (num_entries * X86_GDT_ENTRY_SIZE) - 1;
131 	gdt.ptr = (u32)boot_gdt;
132 
133 	asm volatile("lgdtl %0\n" : : "m" (gdt));
134 }
135 
136 void setup_gdt(gd_t *id, u64 *gdt_addr)
137 {
138 	id->arch.gdt = gdt_addr;
139 	/* CS: code, read/execute, 4 GB, base 0 */
140 	gdt_addr[X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff);
141 
142 	/* DS: data, read/write, 4 GB, base 0 */
143 	gdt_addr[X86_GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff);
144 
145 	/* FS: data, read/write, 4 GB, base (Global Data Pointer) */
146 	id->arch.gd_addr = id;
147 	gdt_addr[X86_GDT_ENTRY_32BIT_FS] = GDT_ENTRY(0xc093,
148 		     (ulong)&id->arch.gd_addr, 0xfffff);
149 
150 	/* 16-bit CS: code, read/execute, 64 kB, base 0 */
151 	gdt_addr[X86_GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x009b, 0, 0x0ffff);
152 
153 	/* 16-bit DS: data, read/write, 64 kB, base 0 */
154 	gdt_addr[X86_GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x0093, 0, 0x0ffff);
155 
156 	gdt_addr[X86_GDT_ENTRY_16BIT_FLAT_CS] = GDT_ENTRY(0x809b, 0, 0xfffff);
157 	gdt_addr[X86_GDT_ENTRY_16BIT_FLAT_DS] = GDT_ENTRY(0x8093, 0, 0xfffff);
158 
159 	load_gdt(gdt_addr, X86_GDT_NUM_ENTRIES);
160 	load_ds(X86_GDT_ENTRY_32BIT_DS);
161 	load_es(X86_GDT_ENTRY_32BIT_DS);
162 	load_gs(X86_GDT_ENTRY_32BIT_DS);
163 	load_ss(X86_GDT_ENTRY_32BIT_DS);
164 	load_fs(X86_GDT_ENTRY_32BIT_FS);
165 }
166 
167 #ifdef CONFIG_HAVE_FSP
168 /*
169  * Setup FSP execution environment GDT
170  *
171  * Per Intel FSP external architecture specification, before calling any FSP
172  * APIs, we need make sure the system is in flat 32-bit mode and both the code
173  * and data selectors should have full 4GB access range. Here we reuse the one
174  * we used in arch/x86/cpu/start16.S, and reload the segement registers.
175  */
176 void setup_fsp_gdt(void)
177 {
178 	load_gdt((const u64 *)(gdt_rom + CONFIG_RESET_SEG_START), 4);
179 	load_ds(X86_GDT_ENTRY_32BIT_DS);
180 	load_ss(X86_GDT_ENTRY_32BIT_DS);
181 	load_es(X86_GDT_ENTRY_32BIT_DS);
182 	load_fs(X86_GDT_ENTRY_32BIT_DS);
183 	load_gs(X86_GDT_ENTRY_32BIT_DS);
184 }
185 #endif
186 
187 int __weak x86_cleanup_before_linux(void)
188 {
189 #ifdef CONFIG_BOOTSTAGE_STASH
190 	bootstage_stash((void *)CONFIG_BOOTSTAGE_STASH_ADDR,
191 			CONFIG_BOOTSTAGE_STASH_SIZE);
192 #endif
193 
194 	return 0;
195 }
196 
197 /*
198  * Cyrix CPUs without cpuid or with cpuid not yet enabled can be detected
199  * by the fact that they preserve the flags across the division of 5/2.
200  * PII and PPro exhibit this behavior too, but they have cpuid available.
201  */
202 
203 /*
204  * Perform the Cyrix 5/2 test. A Cyrix won't change
205  * the flags, while other 486 chips will.
206  */
207 static inline int test_cyrix_52div(void)
208 {
209 	unsigned int test;
210 
211 	__asm__ __volatile__(
212 	     "sahf\n\t"		/* clear flags (%eax = 0x0005) */
213 	     "div %b2\n\t"	/* divide 5 by 2 */
214 	     "lahf"		/* store flags into %ah */
215 	     : "=a" (test)
216 	     : "0" (5), "q" (2)
217 	     : "cc");
218 
219 	/* AH is 0x02 on Cyrix after the divide.. */
220 	return (unsigned char) (test >> 8) == 0x02;
221 }
222 
223 /*
224  *	Detect a NexGen CPU running without BIOS hypercode new enough
225  *	to have CPUID. (Thanks to Herbert Oppmann)
226  */
227 
228 static int deep_magic_nexgen_probe(void)
229 {
230 	int ret;
231 
232 	__asm__ __volatile__ (
233 		"	movw	$0x5555, %%ax\n"
234 		"	xorw	%%dx,%%dx\n"
235 		"	movw	$2, %%cx\n"
236 		"	divw	%%cx\n"
237 		"	movl	$0, %%eax\n"
238 		"	jnz	1f\n"
239 		"	movl	$1, %%eax\n"
240 		"1:\n"
241 		: "=a" (ret) : : "cx", "dx");
242 	return  ret;
243 }
244 
245 static bool has_cpuid(void)
246 {
247 	return flag_is_changeable_p(X86_EFLAGS_ID);
248 }
249 
250 static bool has_mtrr(void)
251 {
252 	return cpuid_edx(0x00000001) & (1 << 12) ? true : false;
253 }
254 
255 static int build_vendor_name(char *vendor_name)
256 {
257 	struct cpuid_result result;
258 	result = cpuid(0x00000000);
259 	unsigned int *name_as_ints = (unsigned int *)vendor_name;
260 
261 	name_as_ints[0] = result.ebx;
262 	name_as_ints[1] = result.edx;
263 	name_as_ints[2] = result.ecx;
264 
265 	return result.eax;
266 }
267 
268 static void identify_cpu(struct cpu_device_id *cpu)
269 {
270 	char vendor_name[16];
271 	int i;
272 
273 	vendor_name[0] = '\0'; /* Unset */
274 	cpu->device = 0; /* fix gcc 4.4.4 warning */
275 
276 	/* Find the id and vendor_name */
277 	if (!has_cpuid()) {
278 		/* Its a 486 if we can modify the AC flag */
279 		if (flag_is_changeable_p(X86_EFLAGS_AC))
280 			cpu->device = 0x00000400; /* 486 */
281 		else
282 			cpu->device = 0x00000300; /* 386 */
283 		if ((cpu->device == 0x00000400) && test_cyrix_52div()) {
284 			memcpy(vendor_name, "CyrixInstead", 13);
285 			/* If we ever care we can enable cpuid here */
286 		}
287 		/* Detect NexGen with old hypercode */
288 		else if (deep_magic_nexgen_probe())
289 			memcpy(vendor_name, "NexGenDriven", 13);
290 	}
291 	if (has_cpuid()) {
292 		int  cpuid_level;
293 
294 		cpuid_level = build_vendor_name(vendor_name);
295 		vendor_name[12] = '\0';
296 
297 		/* Intel-defined flags: level 0x00000001 */
298 		if (cpuid_level >= 0x00000001) {
299 			cpu->device = cpuid_eax(0x00000001);
300 		} else {
301 			/* Have CPUID level 0 only unheard of */
302 			cpu->device = 0x00000400;
303 		}
304 	}
305 	cpu->vendor = X86_VENDOR_UNKNOWN;
306 	for (i = 0; i < ARRAY_SIZE(x86_vendors); i++) {
307 		if (memcmp(vendor_name, x86_vendors[i].name, 12) == 0) {
308 			cpu->vendor = x86_vendors[i].vendor;
309 			break;
310 		}
311 	}
312 }
313 
314 static inline void get_fms(struct cpuinfo_x86 *c, uint32_t tfms)
315 {
316 	c->x86 = (tfms >> 8) & 0xf;
317 	c->x86_model = (tfms >> 4) & 0xf;
318 	c->x86_mask = tfms & 0xf;
319 	if (c->x86 == 0xf)
320 		c->x86 += (tfms >> 20) & 0xff;
321 	if (c->x86 >= 0x6)
322 		c->x86_model += ((tfms >> 16) & 0xF) << 4;
323 }
324 
325 int x86_cpu_init_f(void)
326 {
327 	const u32 em_rst = ~X86_CR0_EM;
328 	const u32 mp_ne_set = X86_CR0_MP | X86_CR0_NE;
329 
330 	/* initialize FPU, reset EM, set MP and NE */
331 	asm ("fninit\n" \
332 	     "movl %%cr0, %%eax\n" \
333 	     "andl %0, %%eax\n" \
334 	     "orl  %1, %%eax\n" \
335 	     "movl %%eax, %%cr0\n" \
336 	     : : "i" (em_rst), "i" (mp_ne_set) : "eax");
337 
338 	/* identify CPU via cpuid and store the decoded info into gd->arch */
339 	if (has_cpuid()) {
340 		struct cpu_device_id cpu;
341 		struct cpuinfo_x86 c;
342 
343 		identify_cpu(&cpu);
344 		get_fms(&c, cpu.device);
345 		gd->arch.x86 = c.x86;
346 		gd->arch.x86_vendor = cpu.vendor;
347 		gd->arch.x86_model = c.x86_model;
348 		gd->arch.x86_mask = c.x86_mask;
349 		gd->arch.x86_device = cpu.device;
350 
351 		gd->arch.has_mtrr = has_mtrr();
352 	}
353 
354 	return 0;
355 }
356 
357 void x86_enable_caches(void)
358 {
359 	unsigned long cr0;
360 
361 	cr0 = read_cr0();
362 	cr0 &= ~(X86_CR0_NW | X86_CR0_CD);
363 	write_cr0(cr0);
364 	wbinvd();
365 }
366 void enable_caches(void) __attribute__((weak, alias("x86_enable_caches")));
367 
368 void x86_disable_caches(void)
369 {
370 	unsigned long cr0;
371 
372 	cr0 = read_cr0();
373 	cr0 |= X86_CR0_NW | X86_CR0_CD;
374 	wbinvd();
375 	write_cr0(cr0);
376 	wbinvd();
377 }
378 void disable_caches(void) __attribute__((weak, alias("x86_disable_caches")));
379 
380 int x86_init_cache(void)
381 {
382 	enable_caches();
383 
384 	return 0;
385 }
386 int init_cache(void) __attribute__((weak, alias("x86_init_cache")));
387 
388 int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
389 {
390 	printf("resetting ...\n");
391 
392 	/* wait 50 ms */
393 	udelay(50000);
394 	disable_interrupts();
395 	reset_cpu(0);
396 
397 	/*NOTREACHED*/
398 	return 0;
399 }
400 
401 void  flush_cache(unsigned long dummy1, unsigned long dummy2)
402 {
403 	asm("wbinvd\n");
404 }
405 
406 __weak void reset_cpu(ulong addr)
407 {
408 	/* Do a hard reset through the chipset's reset control register */
409 	outb(SYS_RST | RST_CPU, PORT_RESET);
410 	for (;;)
411 		cpu_hlt();
412 }
413 
414 void x86_full_reset(void)
415 {
416 	outb(FULL_RST | SYS_RST | RST_CPU, PORT_RESET);
417 }
418 
419 int dcache_status(void)
420 {
421 	return !(read_cr0() & 0x40000000);
422 }
423 
424 /* Define these functions to allow ehch-hcd to function */
425 void flush_dcache_range(unsigned long start, unsigned long stop)
426 {
427 }
428 
429 void invalidate_dcache_range(unsigned long start, unsigned long stop)
430 {
431 }
432 
433 void dcache_enable(void)
434 {
435 	enable_caches();
436 }
437 
438 void dcache_disable(void)
439 {
440 	disable_caches();
441 }
442 
443 void icache_enable(void)
444 {
445 }
446 
447 void icache_disable(void)
448 {
449 }
450 
451 int icache_status(void)
452 {
453 	return 1;
454 }
455 
456 void cpu_enable_paging_pae(ulong cr3)
457 {
458 	__asm__ __volatile__(
459 		/* Load the page table address */
460 		"movl	%0, %%cr3\n"
461 		/* Enable pae */
462 		"movl	%%cr4, %%eax\n"
463 		"orl	$0x00000020, %%eax\n"
464 		"movl	%%eax, %%cr4\n"
465 		/* Enable paging */
466 		"movl	%%cr0, %%eax\n"
467 		"orl	$0x80000000, %%eax\n"
468 		"movl	%%eax, %%cr0\n"
469 		:
470 		: "r" (cr3)
471 		: "eax");
472 }
473 
474 void cpu_disable_paging_pae(void)
475 {
476 	/* Turn off paging */
477 	__asm__ __volatile__ (
478 		/* Disable paging */
479 		"movl	%%cr0, %%eax\n"
480 		"andl	$0x7fffffff, %%eax\n"
481 		"movl	%%eax, %%cr0\n"
482 		/* Disable pae */
483 		"movl	%%cr4, %%eax\n"
484 		"andl	$0xffffffdf, %%eax\n"
485 		"movl	%%eax, %%cr4\n"
486 		:
487 		:
488 		: "eax");
489 }
490 
491 static bool can_detect_long_mode(void)
492 {
493 	return cpuid_eax(0x80000000) > 0x80000000UL;
494 }
495 
496 static bool has_long_mode(void)
497 {
498 	return cpuid_edx(0x80000001) & (1 << 29) ? true : false;
499 }
500 
501 int cpu_has_64bit(void)
502 {
503 	return has_cpuid() && can_detect_long_mode() &&
504 		has_long_mode();
505 }
506 
507 const char *cpu_vendor_name(int vendor)
508 {
509 	const char *name;
510 	name = "<invalid cpu vendor>";
511 	if ((vendor < (ARRAY_SIZE(x86_vendor_name))) &&
512 	    (x86_vendor_name[vendor] != 0))
513 		name = x86_vendor_name[vendor];
514 
515 	return name;
516 }
517 
518 char *cpu_get_name(char *name)
519 {
520 	unsigned int *name_as_ints = (unsigned int *)name;
521 	struct cpuid_result regs;
522 	char *ptr;
523 	int i;
524 
525 	/* This bit adds up to 48 bytes */
526 	for (i = 0; i < 3; i++) {
527 		regs = cpuid(0x80000002 + i);
528 		name_as_ints[i * 4 + 0] = regs.eax;
529 		name_as_ints[i * 4 + 1] = regs.ebx;
530 		name_as_ints[i * 4 + 2] = regs.ecx;
531 		name_as_ints[i * 4 + 3] = regs.edx;
532 	}
533 	name[CPU_MAX_NAME_LEN - 1] = '\0';
534 
535 	/* Skip leading spaces. */
536 	ptr = name;
537 	while (*ptr == ' ')
538 		ptr++;
539 
540 	return ptr;
541 }
542 
543 int x86_cpu_get_desc(struct udevice *dev, char *buf, int size)
544 {
545 	if (size < CPU_MAX_NAME_LEN)
546 		return -ENOSPC;
547 
548 	cpu_get_name(buf);
549 
550 	return 0;
551 }
552 
553 int default_print_cpuinfo(void)
554 {
555 	printf("CPU: %s, vendor %s, device %xh\n",
556 	       cpu_has_64bit() ? "x86_64" : "x86",
557 	       cpu_vendor_name(gd->arch.x86_vendor), gd->arch.x86_device);
558 
559 	return 0;
560 }
561 
562 #define PAGETABLE_SIZE		(6 * 4096)
563 
564 /**
565  * build_pagetable() - build a flat 4GiB page table structure for 64-bti mode
566  *
567  * @pgtable: Pointer to a 24iKB block of memory
568  */
569 static void build_pagetable(uint32_t *pgtable)
570 {
571 	uint i;
572 
573 	memset(pgtable, '\0', PAGETABLE_SIZE);
574 
575 	/* Level 4 needs a single entry */
576 	pgtable[0] = (uint32_t)&pgtable[1024] + 7;
577 
578 	/* Level 3 has one 64-bit entry for each GiB of memory */
579 	for (i = 0; i < 4; i++) {
580 		pgtable[1024 + i * 2] = (uint32_t)&pgtable[2048] +
581 							0x1000 * i + 7;
582 	}
583 
584 	/* Level 2 has 2048 64-bit entries, each repesenting 2MiB */
585 	for (i = 0; i < 2048; i++)
586 		pgtable[2048 + i * 2] = 0x183 + (i << 21UL);
587 }
588 
589 int cpu_jump_to_64bit(ulong setup_base, ulong target)
590 {
591 	uint32_t *pgtable;
592 
593 	pgtable = memalign(4096, PAGETABLE_SIZE);
594 	if (!pgtable)
595 		return -ENOMEM;
596 
597 	build_pagetable(pgtable);
598 	cpu_call64((ulong)pgtable, setup_base, target);
599 	free(pgtable);
600 
601 	return -EFAULT;
602 }
603 
604 void show_boot_progress(int val)
605 {
606 #if MIN_PORT80_KCLOCKS_DELAY
607 	/*
608 	 * Scale the time counter reading to avoid using 64 bit arithmetics.
609 	 * Can't use get_timer() here becuase it could be not yet
610 	 * initialized or even implemented.
611 	 */
612 	if (!gd->arch.tsc_prev) {
613 		gd->arch.tsc_base_kclocks = rdtsc() / 1000;
614 		gd->arch.tsc_prev = 0;
615 	} else {
616 		uint32_t now;
617 
618 		do {
619 			now = rdtsc() / 1000 - gd->arch.tsc_base_kclocks;
620 		} while (now < (gd->arch.tsc_prev + MIN_PORT80_KCLOCKS_DELAY));
621 		gd->arch.tsc_prev = now;
622 	}
623 #endif
624 	outb(val, POST_PORT);
625 }
626 
627 #ifndef CONFIG_SYS_COREBOOT
628 int last_stage_init(void)
629 {
630 	write_tables();
631 
632 	return 0;
633 }
634 #endif
635 
636 __weak int x86_init_cpus(void)
637 {
638 	return 0;
639 }
640 
641 int cpu_init_r(void)
642 {
643 	return x86_init_cpus();
644 }
645 
646 static const struct cpu_ops cpu_x86_ops = {
647 	.get_desc	= x86_cpu_get_desc,
648 };
649 
650 static const struct udevice_id cpu_x86_ids[] = {
651 	{ .compatible = "cpu-x86" },
652 	{ }
653 };
654 
655 U_BOOT_DRIVER(cpu_x86_drv) = {
656 	.name		= "cpu_x86",
657 	.id		= UCLASS_CPU,
658 	.of_match	= cpu_x86_ids,
659 	.ops		= &cpu_x86_ops,
660 };
661