2 * (C) Copyright 2008-2011
3 * Graeme Russ, <graeme.russ@gmail.com>
6 * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
9 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
10 * Marius Groeger <mgroeger@sysgo.de>
13 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
14 * Alex Zuepke <azu@sysgo.de>
16 * Part of this file is adapted from coreboot
17 * src/arch/x86/lib/cpu.c
19 * SPDX-License-Identifier: GPL-2.0+
26 #include <asm/control_regs.h>
29 #include <asm/processor.h>
30 #include <asm/processor-flags.h>
31 #include <asm/interrupt.h>
32 #include <linux/compiler.h>
34 DECLARE_GLOBAL_DATA_PTR;
37 * Constructor for a conventional segment GDT (or LDT) entry
38 * This is a macro so it can be used in initialisers
40 #define GDT_ENTRY(flags, base, limit) \
41 ((((base) & 0xff000000ULL) << (56-24)) | \
42 (((flags) & 0x0000f0ffULL) << 40) | \
43 (((limit) & 0x000f0000ULL) << (48-16)) | \
44 (((base) & 0x00ffffffULL) << 16) | \
45 (((limit) & 0x0000ffffULL)))
52 struct cpu_device_id {
58 uint8_t x86; /* CPU family */
59 uint8_t x86_vendor; /* CPU vendor */
65 * List of cpu vendor strings along with their normalized
72 { X86_VENDOR_INTEL, "GenuineIntel", },
73 { X86_VENDOR_CYRIX, "CyrixInstead", },
74 { X86_VENDOR_AMD, "AuthenticAMD", },
75 { X86_VENDOR_UMC, "UMC UMC UMC ", },
76 { X86_VENDOR_NEXGEN, "NexGenDriven", },
77 { X86_VENDOR_CENTAUR, "CentaurHauls", },
78 { X86_VENDOR_RISE, "RiseRiseRise", },
79 { X86_VENDOR_TRANSMETA, "GenuineTMx86", },
80 { X86_VENDOR_TRANSMETA, "TransmetaCPU", },
81 { X86_VENDOR_NSC, "Geode by NSC", },
82 { X86_VENDOR_SIS, "SiS SiS SiS ", },
85 static const char *const x86_vendor_name[] = {
86 [X86_VENDOR_INTEL] = "Intel",
87 [X86_VENDOR_CYRIX] = "Cyrix",
88 [X86_VENDOR_AMD] = "AMD",
89 [X86_VENDOR_UMC] = "UMC",
90 [X86_VENDOR_NEXGEN] = "NexGen",
91 [X86_VENDOR_CENTAUR] = "Centaur",
92 [X86_VENDOR_RISE] = "Rise",
93 [X86_VENDOR_TRANSMETA] = "Transmeta",
94 [X86_VENDOR_NSC] = "NSC",
95 [X86_VENDOR_SIS] = "SiS",
98 static void load_ds(u32 segment)
100 asm volatile("movl %0, %%ds" : : "r" (segment * X86_GDT_ENTRY_SIZE));
103 static void load_es(u32 segment)
105 asm volatile("movl %0, %%es" : : "r" (segment * X86_GDT_ENTRY_SIZE));
108 static void load_fs(u32 segment)
110 asm volatile("movl %0, %%fs" : : "r" (segment * X86_GDT_ENTRY_SIZE));
113 static void load_gs(u32 segment)
115 asm volatile("movl %0, %%gs" : : "r" (segment * X86_GDT_ENTRY_SIZE));
118 static void load_ss(u32 segment)
120 asm volatile("movl %0, %%ss" : : "r" (segment * X86_GDT_ENTRY_SIZE));
123 static void load_gdt(const u64 *boot_gdt, u16 num_entries)
127 gdt.len = (num_entries * X86_GDT_ENTRY_SIZE) - 1;
128 gdt.ptr = (u32)boot_gdt;
130 asm volatile("lgdtl %0\n" : : "m" (gdt));
133 void setup_gdt(gd_t *id, u64 *gdt_addr)
135 /* CS: code, read/execute, 4 GB, base 0 */
136 gdt_addr[X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff);
138 /* DS: data, read/write, 4 GB, base 0 */
139 gdt_addr[X86_GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff);
141 /* FS: data, read/write, 4 GB, base (Global Data Pointer) */
142 id->arch.gd_addr = id;
143 gdt_addr[X86_GDT_ENTRY_32BIT_FS] = GDT_ENTRY(0xc093,
144 (ulong)&id->arch.gd_addr, 0xfffff);
146 /* 16-bit CS: code, read/execute, 64 kB, base 0 */
147 gdt_addr[X86_GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x009b, 0, 0x0ffff);
149 /* 16-bit DS: data, read/write, 64 kB, base 0 */
150 gdt_addr[X86_GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x0093, 0, 0x0ffff);
152 gdt_addr[X86_GDT_ENTRY_16BIT_FLAT_CS] = GDT_ENTRY(0x809b, 0, 0xfffff);
153 gdt_addr[X86_GDT_ENTRY_16BIT_FLAT_DS] = GDT_ENTRY(0x8093, 0, 0xfffff);
155 load_gdt(gdt_addr, X86_GDT_NUM_ENTRIES);
156 load_ds(X86_GDT_ENTRY_32BIT_DS);
157 load_es(X86_GDT_ENTRY_32BIT_DS);
158 load_gs(X86_GDT_ENTRY_32BIT_DS);
159 load_ss(X86_GDT_ENTRY_32BIT_DS);
160 load_fs(X86_GDT_ENTRY_32BIT_FS);
163 int __weak x86_cleanup_before_linux(void)
165 #ifdef CONFIG_BOOTSTAGE_STASH
166 bootstage_stash((void *)CONFIG_BOOTSTAGE_STASH,
167 CONFIG_BOOTSTAGE_STASH_SIZE);
174 * Cyrix CPUs without cpuid or with cpuid not yet enabled can be detected
175 * by the fact that they preserve the flags across the division of 5/2.
176 * PII and PPro exhibit this behavior too, but they have cpuid available.
180 * Perform the Cyrix 5/2 test. A Cyrix won't change
181 * the flags, while other 486 chips will.
183 static inline int test_cyrix_52div(void)
187 __asm__ __volatile__(
188 "sahf\n\t" /* clear flags (%eax = 0x0005) */
189 "div %b2\n\t" /* divide 5 by 2 */
190 "lahf" /* store flags into %ah */
195 /* AH is 0x02 on Cyrix after the divide.. */
196 return (unsigned char) (test >> 8) == 0x02;
200 * Detect a NexGen CPU running without BIOS hypercode new enough
201 * to have CPUID. (Thanks to Herbert Oppmann)
204 static int deep_magic_nexgen_probe(void)
208 __asm__ __volatile__ (
209 " movw $0x5555, %%ax\n"
217 : "=a" (ret) : : "cx", "dx");
221 static bool has_cpuid(void)
223 return flag_is_changeable_p(X86_EFLAGS_ID);
226 static int build_vendor_name(char *vendor_name)
228 struct cpuid_result result;
229 result = cpuid(0x00000000);
230 unsigned int *name_as_ints = (unsigned int *)vendor_name;
232 name_as_ints[0] = result.ebx;
233 name_as_ints[1] = result.edx;
234 name_as_ints[2] = result.ecx;
239 static void identify_cpu(struct cpu_device_id *cpu)
241 char vendor_name[16];
244 vendor_name[0] = '\0'; /* Unset */
245 cpu->device = 0; /* fix gcc 4.4.4 warning */
247 /* Find the id and vendor_name */
249 /* Its a 486 if we can modify the AC flag */
250 if (flag_is_changeable_p(X86_EFLAGS_AC))
251 cpu->device = 0x00000400; /* 486 */
253 cpu->device = 0x00000300; /* 386 */
254 if ((cpu->device == 0x00000400) && test_cyrix_52div()) {
255 memcpy(vendor_name, "CyrixInstead", 13);
256 /* If we ever care we can enable cpuid here */
258 /* Detect NexGen with old hypercode */
259 else if (deep_magic_nexgen_probe())
260 memcpy(vendor_name, "NexGenDriven", 13);
265 cpuid_level = build_vendor_name(vendor_name);
266 vendor_name[12] = '\0';
268 /* Intel-defined flags: level 0x00000001 */
269 if (cpuid_level >= 0x00000001) {
270 cpu->device = cpuid_eax(0x00000001);
272 /* Have CPUID level 0 only unheard of */
273 cpu->device = 0x00000400;
276 cpu->vendor = X86_VENDOR_UNKNOWN;
277 for (i = 0; i < ARRAY_SIZE(x86_vendors); i++) {
278 if (memcmp(vendor_name, x86_vendors[i].name, 12) == 0) {
279 cpu->vendor = x86_vendors[i].vendor;
285 static inline void get_fms(struct cpuinfo_x86 *c, uint32_t tfms)
287 c->x86 = (tfms >> 8) & 0xf;
288 c->x86_model = (tfms >> 4) & 0xf;
289 c->x86_mask = tfms & 0xf;
291 c->x86 += (tfms >> 20) & 0xff;
293 c->x86_model += ((tfms >> 16) & 0xF) << 4;
296 int x86_cpu_init_f(void)
298 const u32 em_rst = ~X86_CR0_EM;
299 const u32 mp_ne_set = X86_CR0_MP | X86_CR0_NE;
301 /* initialize FPU, reset EM, set MP and NE */
303 "movl %%cr0, %%eax\n" \
306 "movl %%eax, %%cr0\n" \
307 : : "i" (em_rst), "i" (mp_ne_set) : "eax");
309 /* identify CPU via cpuid and store the decoded info into gd->arch */
311 struct cpu_device_id cpu;
312 struct cpuinfo_x86 c;
315 get_fms(&c, cpu.device);
316 gd->arch.x86 = c.x86;
317 gd->arch.x86_vendor = cpu.vendor;
318 gd->arch.x86_model = c.x86_model;
319 gd->arch.x86_mask = c.x86_mask;
320 gd->arch.x86_device = cpu.device;
326 void x86_enable_caches(void)
331 cr0 &= ~(X86_CR0_NW | X86_CR0_CD);
335 void enable_caches(void) __attribute__((weak, alias("x86_enable_caches")));
337 void x86_disable_caches(void)
342 cr0 |= X86_CR0_NW | X86_CR0_CD;
347 void disable_caches(void) __attribute__((weak, alias("x86_disable_caches")));
349 int x86_init_cache(void)
355 int init_cache(void) __attribute__((weak, alias("x86_init_cache")));
357 int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
359 printf("resetting ...\n");
363 disable_interrupts();
370 void flush_cache(unsigned long dummy1, unsigned long dummy2)
375 void __attribute__ ((regparm(0))) generate_gpf(void);
377 /* segment 0x70 is an arbitrary segment which does not exist */
378 asm(".globl generate_gpf\n"
379 ".hidden generate_gpf\n"
380 ".type generate_gpf, @function\n"
382 "ljmp $0x70, $0x47114711\n");
384 __weak void reset_cpu(ulong addr)
386 printf("Resetting using x86 Triple Fault\n");
387 set_vector(13, generate_gpf); /* general protection fault handler */
388 set_vector(8, generate_gpf); /* double fault handler */
389 generate_gpf(); /* start the show */
392 int dcache_status(void)
394 return !(read_cr0() & 0x40000000);
397 /* Define these functions to allow ehch-hcd to function */
398 void flush_dcache_range(unsigned long start, unsigned long stop)
402 void invalidate_dcache_range(unsigned long start, unsigned long stop)
406 void dcache_enable(void)
411 void dcache_disable(void)
416 void icache_enable(void)
420 void icache_disable(void)
424 int icache_status(void)
429 void cpu_enable_paging_pae(ulong cr3)
431 __asm__ __volatile__(
432 /* Load the page table address */
435 "movl %%cr4, %%eax\n"
436 "orl $0x00000020, %%eax\n"
437 "movl %%eax, %%cr4\n"
439 "movl %%cr0, %%eax\n"
440 "orl $0x80000000, %%eax\n"
441 "movl %%eax, %%cr0\n"
447 void cpu_disable_paging_pae(void)
449 /* Turn off paging */
450 __asm__ __volatile__ (
452 "movl %%cr0, %%eax\n"
453 "andl $0x7fffffff, %%eax\n"
454 "movl %%eax, %%cr0\n"
456 "movl %%cr4, %%eax\n"
457 "andl $0xffffffdf, %%eax\n"
458 "movl %%eax, %%cr4\n"
464 static bool can_detect_long_mode(void)
466 return cpuid_eax(0x80000000) > 0x80000000UL;
469 static bool has_long_mode(void)
471 return cpuid_edx(0x80000001) & (1 << 29) ? true : false;
474 int cpu_has_64bit(void)
476 return has_cpuid() && can_detect_long_mode() &&
480 const char *cpu_vendor_name(int vendor)
483 name = "<invalid cpu vendor>";
484 if ((vendor < (ARRAY_SIZE(x86_vendor_name))) &&
485 (x86_vendor_name[vendor] != 0))
486 name = x86_vendor_name[vendor];
491 char *cpu_get_name(char *name)
493 unsigned int *name_as_ints = (unsigned int *)name;
494 struct cpuid_result regs;
498 /* This bit adds up to 48 bytes */
499 for (i = 0; i < 3; i++) {
500 regs = cpuid(0x80000002 + i);
501 name_as_ints[i * 4 + 0] = regs.eax;
502 name_as_ints[i * 4 + 1] = regs.ebx;
503 name_as_ints[i * 4 + 2] = regs.ecx;
504 name_as_ints[i * 4 + 3] = regs.edx;
506 name[CPU_MAX_NAME_LEN - 1] = '\0';
508 /* Skip leading spaces. */
516 int default_print_cpuinfo(void)
518 printf("CPU: %s, vendor %s, device %xh\n",
519 cpu_has_64bit() ? "x86_64" : "x86",
520 cpu_vendor_name(gd->arch.x86_vendor), gd->arch.x86_device);
525 #define PAGETABLE_SIZE (6 * 4096)
528 * build_pagetable() - build a flat 4GiB page table structure for 64-bti mode
530 * @pgtable: Pointer to a 24iKB block of memory
532 static void build_pagetable(uint32_t *pgtable)
536 memset(pgtable, '\0', PAGETABLE_SIZE);
538 /* Level 4 needs a single entry */
539 pgtable[0] = (uint32_t)&pgtable[1024] + 7;
541 /* Level 3 has one 64-bit entry for each GiB of memory */
542 for (i = 0; i < 4; i++) {
543 pgtable[1024 + i * 2] = (uint32_t)&pgtable[2048] +
547 /* Level 2 has 2048 64-bit entries, each repesenting 2MiB */
548 for (i = 0; i < 2048; i++)
549 pgtable[2048 + i * 2] = 0x183 + (i << 21UL);
552 int cpu_jump_to_64bit(ulong setup_base, ulong target)
556 pgtable = memalign(4096, PAGETABLE_SIZE);
560 build_pagetable(pgtable);
561 cpu_call64((ulong)pgtable, setup_base, target);
567 void show_boot_progress(int val)
569 #if MIN_PORT80_KCLOCKS_DELAY
571 * Scale the time counter reading to avoid using 64 bit arithmetics.
572 * Can't use get_timer() here becuase it could be not yet
573 * initialized or even implemented.
575 if (!gd->arch.tsc_prev) {
576 gd->arch.tsc_base_kclocks = rdtsc() / 1000;
577 gd->arch.tsc_prev = 0;
582 now = rdtsc() / 1000 - gd->arch.tsc_base_kclocks;
583 } while (now < (gd->arch.tsc_prev + MIN_PORT80_KCLOCKS_DELAY));
584 gd->arch.tsc_prev = now;
587 outb(val, POST_PORT);