xref: /openbmc/u-boot/arch/x86/cpu/cpu.c (revision be3f06bc)
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 <errno.h>
25 #include <malloc.h>
26 #include <asm/control_regs.h>
27 #include <asm/cpu.h>
28 #include <asm/post.h>
29 #include <asm/processor.h>
30 #include <asm/processor-flags.h>
31 #include <asm/interrupt.h>
32 #include <asm/tables.h>
33 #include <linux/compiler.h>
34 
35 DECLARE_GLOBAL_DATA_PTR;
36 
37 /*
38  * Constructor for a conventional segment GDT (or LDT) entry
39  * This is a macro so it can be used in initialisers
40  */
41 #define GDT_ENTRY(flags, base, limit)			\
42 	((((base)  & 0xff000000ULL) << (56-24)) |	\
43 	 (((flags) & 0x0000f0ffULL) << 40) |		\
44 	 (((limit) & 0x000f0000ULL) << (48-16)) |	\
45 	 (((base)  & 0x00ffffffULL) << 16) |		\
46 	 (((limit) & 0x0000ffffULL)))
47 
48 struct gdt_ptr {
49 	u16 len;
50 	u32 ptr;
51 } __packed;
52 
53 struct cpu_device_id {
54 	unsigned vendor;
55 	unsigned device;
56 };
57 
58 struct cpuinfo_x86 {
59 	uint8_t x86;            /* CPU family */
60 	uint8_t x86_vendor;     /* CPU vendor */
61 	uint8_t x86_model;
62 	uint8_t x86_mask;
63 };
64 
65 /*
66  * List of cpu vendor strings along with their normalized
67  * id values.
68  */
69 static struct {
70 	int vendor;
71 	const char *name;
72 } x86_vendors[] = {
73 	{ X86_VENDOR_INTEL,     "GenuineIntel", },
74 	{ X86_VENDOR_CYRIX,     "CyrixInstead", },
75 	{ X86_VENDOR_AMD,       "AuthenticAMD", },
76 	{ X86_VENDOR_UMC,       "UMC UMC UMC ", },
77 	{ X86_VENDOR_NEXGEN,    "NexGenDriven", },
78 	{ X86_VENDOR_CENTAUR,   "CentaurHauls", },
79 	{ X86_VENDOR_RISE,      "RiseRiseRise", },
80 	{ X86_VENDOR_TRANSMETA, "GenuineTMx86", },
81 	{ X86_VENDOR_TRANSMETA, "TransmetaCPU", },
82 	{ X86_VENDOR_NSC,       "Geode by NSC", },
83 	{ X86_VENDOR_SIS,       "SiS SiS SiS ", },
84 };
85 
86 static const char *const x86_vendor_name[] = {
87 	[X86_VENDOR_INTEL]     = "Intel",
88 	[X86_VENDOR_CYRIX]     = "Cyrix",
89 	[X86_VENDOR_AMD]       = "AMD",
90 	[X86_VENDOR_UMC]       = "UMC",
91 	[X86_VENDOR_NEXGEN]    = "NexGen",
92 	[X86_VENDOR_CENTAUR]   = "Centaur",
93 	[X86_VENDOR_RISE]      = "Rise",
94 	[X86_VENDOR_TRANSMETA] = "Transmeta",
95 	[X86_VENDOR_NSC]       = "NSC",
96 	[X86_VENDOR_SIS]       = "SiS",
97 };
98 
99 static void load_ds(u32 segment)
100 {
101 	asm volatile("movl %0, %%ds" : : "r" (segment * X86_GDT_ENTRY_SIZE));
102 }
103 
104 static void load_es(u32 segment)
105 {
106 	asm volatile("movl %0, %%es" : : "r" (segment * X86_GDT_ENTRY_SIZE));
107 }
108 
109 static void load_fs(u32 segment)
110 {
111 	asm volatile("movl %0, %%fs" : : "r" (segment * X86_GDT_ENTRY_SIZE));
112 }
113 
114 static void load_gs(u32 segment)
115 {
116 	asm volatile("movl %0, %%gs" : : "r" (segment * X86_GDT_ENTRY_SIZE));
117 }
118 
119 static void load_ss(u32 segment)
120 {
121 	asm volatile("movl %0, %%ss" : : "r" (segment * X86_GDT_ENTRY_SIZE));
122 }
123 
124 static void load_gdt(const u64 *boot_gdt, u16 num_entries)
125 {
126 	struct gdt_ptr gdt;
127 
128 	gdt.len = (num_entries * X86_GDT_ENTRY_SIZE) - 1;
129 	gdt.ptr = (u32)boot_gdt;
130 
131 	asm volatile("lgdtl %0\n" : : "m" (gdt));
132 }
133 
134 void setup_gdt(gd_t *id, u64 *gdt_addr)
135 {
136 	id->arch.gdt = gdt_addr;
137 	/* CS: code, read/execute, 4 GB, base 0 */
138 	gdt_addr[X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff);
139 
140 	/* DS: data, read/write, 4 GB, base 0 */
141 	gdt_addr[X86_GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff);
142 
143 	/* FS: data, read/write, 4 GB, base (Global Data Pointer) */
144 	id->arch.gd_addr = id;
145 	gdt_addr[X86_GDT_ENTRY_32BIT_FS] = GDT_ENTRY(0xc093,
146 		     (ulong)&id->arch.gd_addr, 0xfffff);
147 
148 	/* 16-bit CS: code, read/execute, 64 kB, base 0 */
149 	gdt_addr[X86_GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x009b, 0, 0x0ffff);
150 
151 	/* 16-bit DS: data, read/write, 64 kB, base 0 */
152 	gdt_addr[X86_GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x0093, 0, 0x0ffff);
153 
154 	gdt_addr[X86_GDT_ENTRY_16BIT_FLAT_CS] = GDT_ENTRY(0x809b, 0, 0xfffff);
155 	gdt_addr[X86_GDT_ENTRY_16BIT_FLAT_DS] = GDT_ENTRY(0x8093, 0, 0xfffff);
156 
157 	load_gdt(gdt_addr, X86_GDT_NUM_ENTRIES);
158 	load_ds(X86_GDT_ENTRY_32BIT_DS);
159 	load_es(X86_GDT_ENTRY_32BIT_DS);
160 	load_gs(X86_GDT_ENTRY_32BIT_DS);
161 	load_ss(X86_GDT_ENTRY_32BIT_DS);
162 	load_fs(X86_GDT_ENTRY_32BIT_FS);
163 }
164 
165 #ifdef CONFIG_HAVE_FSP
166 /*
167  * Setup FSP execution environment GDT
168  *
169  * Per Intel FSP external architecture specification, before calling any FSP
170  * APIs, we need make sure the system is in flat 32-bit mode and both the code
171  * and data selectors should have full 4GB access range. Here we reuse the one
172  * we used in arch/x86/cpu/start16.S, and reload the segement registers.
173  */
174 void setup_fsp_gdt(void)
175 {
176 	load_gdt((const u64 *)(gdt_rom + CONFIG_RESET_SEG_START), 4);
177 	load_ds(X86_GDT_ENTRY_32BIT_DS);
178 	load_ss(X86_GDT_ENTRY_32BIT_DS);
179 	load_es(X86_GDT_ENTRY_32BIT_DS);
180 	load_fs(X86_GDT_ENTRY_32BIT_DS);
181 	load_gs(X86_GDT_ENTRY_32BIT_DS);
182 }
183 #endif
184 
185 int __weak x86_cleanup_before_linux(void)
186 {
187 #ifdef CONFIG_BOOTSTAGE_STASH
188 	bootstage_stash((void *)CONFIG_BOOTSTAGE_STASH_ADDR,
189 			CONFIG_BOOTSTAGE_STASH_SIZE);
190 #endif
191 
192 	return 0;
193 }
194 
195 /*
196  * Cyrix CPUs without cpuid or with cpuid not yet enabled can be detected
197  * by the fact that they preserve the flags across the division of 5/2.
198  * PII and PPro exhibit this behavior too, but they have cpuid available.
199  */
200 
201 /*
202  * Perform the Cyrix 5/2 test. A Cyrix won't change
203  * the flags, while other 486 chips will.
204  */
205 static inline int test_cyrix_52div(void)
206 {
207 	unsigned int test;
208 
209 	__asm__ __volatile__(
210 	     "sahf\n\t"		/* clear flags (%eax = 0x0005) */
211 	     "div %b2\n\t"	/* divide 5 by 2 */
212 	     "lahf"		/* store flags into %ah */
213 	     : "=a" (test)
214 	     : "0" (5), "q" (2)
215 	     : "cc");
216 
217 	/* AH is 0x02 on Cyrix after the divide.. */
218 	return (unsigned char) (test >> 8) == 0x02;
219 }
220 
221 /*
222  *	Detect a NexGen CPU running without BIOS hypercode new enough
223  *	to have CPUID. (Thanks to Herbert Oppmann)
224  */
225 
226 static int deep_magic_nexgen_probe(void)
227 {
228 	int ret;
229 
230 	__asm__ __volatile__ (
231 		"	movw	$0x5555, %%ax\n"
232 		"	xorw	%%dx,%%dx\n"
233 		"	movw	$2, %%cx\n"
234 		"	divw	%%cx\n"
235 		"	movl	$0, %%eax\n"
236 		"	jnz	1f\n"
237 		"	movl	$1, %%eax\n"
238 		"1:\n"
239 		: "=a" (ret) : : "cx", "dx");
240 	return  ret;
241 }
242 
243 static bool has_cpuid(void)
244 {
245 	return flag_is_changeable_p(X86_EFLAGS_ID);
246 }
247 
248 static bool has_mtrr(void)
249 {
250 	return cpuid_edx(0x00000001) & (1 << 12) ? true : false;
251 }
252 
253 static int build_vendor_name(char *vendor_name)
254 {
255 	struct cpuid_result result;
256 	result = cpuid(0x00000000);
257 	unsigned int *name_as_ints = (unsigned int *)vendor_name;
258 
259 	name_as_ints[0] = result.ebx;
260 	name_as_ints[1] = result.edx;
261 	name_as_ints[2] = result.ecx;
262 
263 	return result.eax;
264 }
265 
266 static void identify_cpu(struct cpu_device_id *cpu)
267 {
268 	char vendor_name[16];
269 	int i;
270 
271 	vendor_name[0] = '\0'; /* Unset */
272 	cpu->device = 0; /* fix gcc 4.4.4 warning */
273 
274 	/* Find the id and vendor_name */
275 	if (!has_cpuid()) {
276 		/* Its a 486 if we can modify the AC flag */
277 		if (flag_is_changeable_p(X86_EFLAGS_AC))
278 			cpu->device = 0x00000400; /* 486 */
279 		else
280 			cpu->device = 0x00000300; /* 386 */
281 		if ((cpu->device == 0x00000400) && test_cyrix_52div()) {
282 			memcpy(vendor_name, "CyrixInstead", 13);
283 			/* If we ever care we can enable cpuid here */
284 		}
285 		/* Detect NexGen with old hypercode */
286 		else if (deep_magic_nexgen_probe())
287 			memcpy(vendor_name, "NexGenDriven", 13);
288 	}
289 	if (has_cpuid()) {
290 		int  cpuid_level;
291 
292 		cpuid_level = build_vendor_name(vendor_name);
293 		vendor_name[12] = '\0';
294 
295 		/* Intel-defined flags: level 0x00000001 */
296 		if (cpuid_level >= 0x00000001) {
297 			cpu->device = cpuid_eax(0x00000001);
298 		} else {
299 			/* Have CPUID level 0 only unheard of */
300 			cpu->device = 0x00000400;
301 		}
302 	}
303 	cpu->vendor = X86_VENDOR_UNKNOWN;
304 	for (i = 0; i < ARRAY_SIZE(x86_vendors); i++) {
305 		if (memcmp(vendor_name, x86_vendors[i].name, 12) == 0) {
306 			cpu->vendor = x86_vendors[i].vendor;
307 			break;
308 		}
309 	}
310 }
311 
312 static inline void get_fms(struct cpuinfo_x86 *c, uint32_t tfms)
313 {
314 	c->x86 = (tfms >> 8) & 0xf;
315 	c->x86_model = (tfms >> 4) & 0xf;
316 	c->x86_mask = tfms & 0xf;
317 	if (c->x86 == 0xf)
318 		c->x86 += (tfms >> 20) & 0xff;
319 	if (c->x86 >= 0x6)
320 		c->x86_model += ((tfms >> 16) & 0xF) << 4;
321 }
322 
323 int x86_cpu_init_f(void)
324 {
325 	const u32 em_rst = ~X86_CR0_EM;
326 	const u32 mp_ne_set = X86_CR0_MP | X86_CR0_NE;
327 
328 	/* initialize FPU, reset EM, set MP and NE */
329 	asm ("fninit\n" \
330 	     "movl %%cr0, %%eax\n" \
331 	     "andl %0, %%eax\n" \
332 	     "orl  %1, %%eax\n" \
333 	     "movl %%eax, %%cr0\n" \
334 	     : : "i" (em_rst), "i" (mp_ne_set) : "eax");
335 
336 	/* identify CPU via cpuid and store the decoded info into gd->arch */
337 	if (has_cpuid()) {
338 		struct cpu_device_id cpu;
339 		struct cpuinfo_x86 c;
340 
341 		identify_cpu(&cpu);
342 		get_fms(&c, cpu.device);
343 		gd->arch.x86 = c.x86;
344 		gd->arch.x86_vendor = cpu.vendor;
345 		gd->arch.x86_model = c.x86_model;
346 		gd->arch.x86_mask = c.x86_mask;
347 		gd->arch.x86_device = cpu.device;
348 
349 		gd->arch.has_mtrr = has_mtrr();
350 	}
351 
352 	return 0;
353 }
354 
355 void x86_enable_caches(void)
356 {
357 	unsigned long cr0;
358 
359 	cr0 = read_cr0();
360 	cr0 &= ~(X86_CR0_NW | X86_CR0_CD);
361 	write_cr0(cr0);
362 	wbinvd();
363 }
364 void enable_caches(void) __attribute__((weak, alias("x86_enable_caches")));
365 
366 void x86_disable_caches(void)
367 {
368 	unsigned long cr0;
369 
370 	cr0 = read_cr0();
371 	cr0 |= X86_CR0_NW | X86_CR0_CD;
372 	wbinvd();
373 	write_cr0(cr0);
374 	wbinvd();
375 }
376 void disable_caches(void) __attribute__((weak, alias("x86_disable_caches")));
377 
378 int x86_init_cache(void)
379 {
380 	enable_caches();
381 
382 	return 0;
383 }
384 int init_cache(void) __attribute__((weak, alias("x86_init_cache")));
385 
386 int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
387 {
388 	printf("resetting ...\n");
389 
390 	/* wait 50 ms */
391 	udelay(50000);
392 	disable_interrupts();
393 	reset_cpu(0);
394 
395 	/*NOTREACHED*/
396 	return 0;
397 }
398 
399 void  flush_cache(unsigned long dummy1, unsigned long dummy2)
400 {
401 	asm("wbinvd\n");
402 }
403 
404 __weak void reset_cpu(ulong addr)
405 {
406 	/* Do a hard reset through the chipset's reset control register */
407 	outb(SYS_RST | RST_CPU, PORT_RESET);
408 	for (;;)
409 		cpu_hlt();
410 }
411 
412 void x86_full_reset(void)
413 {
414 	outb(FULL_RST | SYS_RST | RST_CPU, PORT_RESET);
415 }
416 
417 int dcache_status(void)
418 {
419 	return !(read_cr0() & 0x40000000);
420 }
421 
422 /* Define these functions to allow ehch-hcd to function */
423 void flush_dcache_range(unsigned long start, unsigned long stop)
424 {
425 }
426 
427 void invalidate_dcache_range(unsigned long start, unsigned long stop)
428 {
429 }
430 
431 void dcache_enable(void)
432 {
433 	enable_caches();
434 }
435 
436 void dcache_disable(void)
437 {
438 	disable_caches();
439 }
440 
441 void icache_enable(void)
442 {
443 }
444 
445 void icache_disable(void)
446 {
447 }
448 
449 int icache_status(void)
450 {
451 	return 1;
452 }
453 
454 void cpu_enable_paging_pae(ulong cr3)
455 {
456 	__asm__ __volatile__(
457 		/* Load the page table address */
458 		"movl	%0, %%cr3\n"
459 		/* Enable pae */
460 		"movl	%%cr4, %%eax\n"
461 		"orl	$0x00000020, %%eax\n"
462 		"movl	%%eax, %%cr4\n"
463 		/* Enable paging */
464 		"movl	%%cr0, %%eax\n"
465 		"orl	$0x80000000, %%eax\n"
466 		"movl	%%eax, %%cr0\n"
467 		:
468 		: "r" (cr3)
469 		: "eax");
470 }
471 
472 void cpu_disable_paging_pae(void)
473 {
474 	/* Turn off paging */
475 	__asm__ __volatile__ (
476 		/* Disable paging */
477 		"movl	%%cr0, %%eax\n"
478 		"andl	$0x7fffffff, %%eax\n"
479 		"movl	%%eax, %%cr0\n"
480 		/* Disable pae */
481 		"movl	%%cr4, %%eax\n"
482 		"andl	$0xffffffdf, %%eax\n"
483 		"movl	%%eax, %%cr4\n"
484 		:
485 		:
486 		: "eax");
487 }
488 
489 static bool can_detect_long_mode(void)
490 {
491 	return cpuid_eax(0x80000000) > 0x80000000UL;
492 }
493 
494 static bool has_long_mode(void)
495 {
496 	return cpuid_edx(0x80000001) & (1 << 29) ? true : false;
497 }
498 
499 int cpu_has_64bit(void)
500 {
501 	return has_cpuid() && can_detect_long_mode() &&
502 		has_long_mode();
503 }
504 
505 const char *cpu_vendor_name(int vendor)
506 {
507 	const char *name;
508 	name = "<invalid cpu vendor>";
509 	if ((vendor < (ARRAY_SIZE(x86_vendor_name))) &&
510 	    (x86_vendor_name[vendor] != 0))
511 		name = x86_vendor_name[vendor];
512 
513 	return name;
514 }
515 
516 char *cpu_get_name(char *name)
517 {
518 	unsigned int *name_as_ints = (unsigned int *)name;
519 	struct cpuid_result regs;
520 	char *ptr;
521 	int i;
522 
523 	/* This bit adds up to 48 bytes */
524 	for (i = 0; i < 3; i++) {
525 		regs = cpuid(0x80000002 + i);
526 		name_as_ints[i * 4 + 0] = regs.eax;
527 		name_as_ints[i * 4 + 1] = regs.ebx;
528 		name_as_ints[i * 4 + 2] = regs.ecx;
529 		name_as_ints[i * 4 + 3] = regs.edx;
530 	}
531 	name[CPU_MAX_NAME_LEN - 1] = '\0';
532 
533 	/* Skip leading spaces. */
534 	ptr = name;
535 	while (*ptr == ' ')
536 		ptr++;
537 
538 	return ptr;
539 }
540 
541 int default_print_cpuinfo(void)
542 {
543 	printf("CPU: %s, vendor %s, device %xh\n",
544 	       cpu_has_64bit() ? "x86_64" : "x86",
545 	       cpu_vendor_name(gd->arch.x86_vendor), gd->arch.x86_device);
546 
547 	return 0;
548 }
549 
550 #define PAGETABLE_SIZE		(6 * 4096)
551 
552 /**
553  * build_pagetable() - build a flat 4GiB page table structure for 64-bti mode
554  *
555  * @pgtable: Pointer to a 24iKB block of memory
556  */
557 static void build_pagetable(uint32_t *pgtable)
558 {
559 	uint i;
560 
561 	memset(pgtable, '\0', PAGETABLE_SIZE);
562 
563 	/* Level 4 needs a single entry */
564 	pgtable[0] = (uint32_t)&pgtable[1024] + 7;
565 
566 	/* Level 3 has one 64-bit entry for each GiB of memory */
567 	for (i = 0; i < 4; i++) {
568 		pgtable[1024 + i * 2] = (uint32_t)&pgtable[2048] +
569 							0x1000 * i + 7;
570 	}
571 
572 	/* Level 2 has 2048 64-bit entries, each repesenting 2MiB */
573 	for (i = 0; i < 2048; i++)
574 		pgtable[2048 + i * 2] = 0x183 + (i << 21UL);
575 }
576 
577 int cpu_jump_to_64bit(ulong setup_base, ulong target)
578 {
579 	uint32_t *pgtable;
580 
581 	pgtable = memalign(4096, PAGETABLE_SIZE);
582 	if (!pgtable)
583 		return -ENOMEM;
584 
585 	build_pagetable(pgtable);
586 	cpu_call64((ulong)pgtable, setup_base, target);
587 	free(pgtable);
588 
589 	return -EFAULT;
590 }
591 
592 void show_boot_progress(int val)
593 {
594 #if MIN_PORT80_KCLOCKS_DELAY
595 	/*
596 	 * Scale the time counter reading to avoid using 64 bit arithmetics.
597 	 * Can't use get_timer() here becuase it could be not yet
598 	 * initialized or even implemented.
599 	 */
600 	if (!gd->arch.tsc_prev) {
601 		gd->arch.tsc_base_kclocks = rdtsc() / 1000;
602 		gd->arch.tsc_prev = 0;
603 	} else {
604 		uint32_t now;
605 
606 		do {
607 			now = rdtsc() / 1000 - gd->arch.tsc_base_kclocks;
608 		} while (now < (gd->arch.tsc_prev + MIN_PORT80_KCLOCKS_DELAY));
609 		gd->arch.tsc_prev = now;
610 	}
611 #endif
612 	outb(val, POST_PORT);
613 }
614 
615 #ifndef CONFIG_SYS_COREBOOT
616 int last_stage_init(void)
617 {
618 	write_tables();
619 
620 	return 0;
621 }
622 #endif
623 
624 __weak int x86_init_cpus(void)
625 {
626 	return 0;
627 }
628 
629 int cpu_init_r(void)
630 {
631 	return x86_init_cpus();
632 }
633