u-boot/arch/x86/cpu/i386/cpu.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2008-2011
* Graeme Russ, <graeme.russ@gmail.com>
*
* (C) Copyright 2002
* Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <mgroeger@sysgo.de>
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Alex Zuepke <azu@sysgo.de>
*
* Part of this file is adapted from coreboot
* src/arch/x86/lib/cpu.c
*/
#include <common.h>
#include <cpu_func.h>
#include <init.h>
#include <malloc.h>
#include <spl.h>
#include <asm/control_regs.h>
#include <asm/coreboot_tables.h>
#include <asm/cpu.h>
#include <asm/mp.h>
#include <asm/msr.h>
#include <asm/mtrr.h>
#include <asm/processor-flags.h>
DECLARE_GLOBAL_DATA_PTR;
/*
* Constructor for a conventional segment GDT (or LDT) entry
* This is a macro so it can be used in initialisers
*/
#define GDT_ENTRY(flags, base, limit) \
((((base) & 0xff000000ULL) << (56-24)) | \
(((flags) & 0x0000f0ffULL) << 40) | \
(((limit) & 0x000f0000ULL) << (48-16)) | \
(((base) & 0x00ffffffULL) << 16) | \
(((limit) & 0x0000ffffULL)))
struct gdt_ptr {
u16 len;
u32 ptr;
} __packed;
struct cpu_device_id {
unsigned vendor;
unsigned device;
};
struct cpuinfo_x86 {
uint8_t x86; /* CPU family */
uint8_t x86_vendor; /* CPU vendor */
uint8_t x86_model;
uint8_t x86_mask;
};
/* gcc 7.3 does not wwant to drop x86_vendors, so use #ifdef */
#ifndef CONFIG_TPL_BUILD
/*
* List of cpu vendor strings along with their normalized
* id values.
*/
static const struct {
int vendor;
const char *name;
} x86_vendors[] = {
{ X86_VENDOR_INTEL, "GenuineIntel", },
{ X86_VENDOR_CYRIX, "CyrixInstead", },
{ X86_VENDOR_AMD, "AuthenticAMD", },
{ X86_VENDOR_UMC, "UMC UMC UMC ", },
{ X86_VENDOR_NEXGEN, "NexGenDriven", },
{ X86_VENDOR_CENTAUR, "CentaurHauls", },
{ X86_VENDOR_RISE, "RiseRiseRise", },
{ X86_VENDOR_TRANSMETA, "GenuineTMx86", },
{ X86_VENDOR_TRANSMETA, "TransmetaCPU", },
{ X86_VENDOR_NSC, "Geode by NSC", },
{ X86_VENDOR_SIS, "SiS SiS SiS ", },
};
#endif
static void load_ds(u32 segment)
{
asm volatile("movl %0, %%ds" : : "r" (segment * X86_GDT_ENTRY_SIZE));
}
static void load_es(u32 segment)
{
asm volatile("movl %0, %%es" : : "r" (segment * X86_GDT_ENTRY_SIZE));
}
static void load_fs(u32 segment)
{
asm volatile("movl %0, %%fs" : : "r" (segment * X86_GDT_ENTRY_SIZE));
}
static void load_gs(u32 segment)
{
asm volatile("movl %0, %%gs" : : "r" (segment * X86_GDT_ENTRY_SIZE));
}
static void load_ss(u32 segment)
{
asm volatile("movl %0, %%ss" : : "r" (segment * X86_GDT_ENTRY_SIZE));
}
static void load_gdt(const u64 *boot_gdt, u16 num_entries)
{
struct gdt_ptr gdt;
gdt.len = (num_entries * X86_GDT_ENTRY_SIZE) - 1;
gdt.ptr = (ulong)boot_gdt;
asm volatile("lgdtl %0\n" : : "m" (gdt));
}
void arch_setup_gd(gd_t *new_gd)
{
u64 *gdt_addr;
gdt_addr = new_gd->arch.gdt;
/*
* CS: code, read/execute, 4 GB, base 0
*
* Some OS (like VxWorks) requires GDT entry 1 to be the 32-bit CS
*/
gdt_addr[X86_GDT_ENTRY_UNUSED] = GDT_ENTRY(0xc09b, 0, 0xfffff);
gdt_addr[X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff);
/* DS: data, read/write, 4 GB, base 0 */
gdt_addr[X86_GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff);
/*
* FS: data, read/write, sizeof (Global Data Pointer),
* base (Global Data Pointer)
*/
new_gd->arch.gd_addr = new_gd;
gdt_addr[X86_GDT_ENTRY_32BIT_FS] = GDT_ENTRY(0x8093,
(ulong)&new_gd->arch.gd_addr,
sizeof(new_gd->arch.gd_addr) - 1);
/* 16-bit CS: code, read/execute, 64 kB, base 0 */
gdt_addr[X86_GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x009b, 0, 0x0ffff);
/* 16-bit DS: data, read/write, 64 kB, base 0 */
gdt_addr[X86_GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x0093, 0, 0x0ffff);
gdt_addr[X86_GDT_ENTRY_16BIT_FLAT_CS] = GDT_ENTRY(0x809b, 0, 0xfffff);
gdt_addr[X86_GDT_ENTRY_16BIT_FLAT_DS] = GDT_ENTRY(0x8093, 0, 0xfffff);
load_gdt(gdt_addr, X86_GDT_NUM_ENTRIES);
load_ds(X86_GDT_ENTRY_32BIT_DS);
load_es(X86_GDT_ENTRY_32BIT_DS);
load_gs(X86_GDT_ENTRY_32BIT_DS);
load_ss(X86_GDT_ENTRY_32BIT_DS);
load_fs(X86_GDT_ENTRY_32BIT_FS);
}
#ifdef CONFIG_HAVE_FSP
/*
* Setup FSP execution environment GDT
*
* Per Intel FSP external architecture specification, before calling any FSP
* APIs, we need make sure the system is in flat 32-bit mode and both the code
* and data selectors should have full 4GB access range. Here we reuse the one
* we used in arch/x86/cpu/start16.S, and reload the segement registers.
*/
void setup_fsp_gdt(void)
{
load_gdt((const u64 *)(gdt_rom + CONFIG_RESET_SEG_START), 4);
load_ds(X86_GDT_ENTRY_32BIT_DS);
load_ss(X86_GDT_ENTRY_32BIT_DS);
load_es(X86_GDT_ENTRY_32BIT_DS);
load_fs(X86_GDT_ENTRY_32BIT_DS);
load_gs(X86_GDT_ENTRY_32BIT_DS);
}
#endif
/*
* Cyrix CPUs without cpuid or with cpuid not yet enabled can be detected
* by the fact that they preserve the flags across the division of 5/2.
* PII and PPro exhibit this behavior too, but they have cpuid available.
*/
/*
* Perform the Cyrix 5/2 test. A Cyrix won't change
* the flags, while other 486 chips will.
*/
static inline int test_cyrix_52div(void)
{
unsigned int test;
__asm__ __volatile__(
"sahf\n\t" /* clear flags (%eax = 0x0005) */
"div %b2\n\t" /* divide 5 by 2 */
"lahf" /* store flags into %ah */
: "=a" (test)
: "0" (5), "q" (2)
: "cc");
/* AH is 0x02 on Cyrix after the divide.. */
return (unsigned char) (test >> 8) == 0x02;
}
#ifndef CONFIG_TPL_BUILD
/*
* Detect a NexGen CPU running without BIOS hypercode new enough
* to have CPUID. (Thanks to Herbert Oppmann)
*/
static int deep_magic_nexgen_probe(void)
{
int ret;
__asm__ __volatile__ (
" movw $0x5555, %%ax\n"
" xorw %%dx,%%dx\n"
" movw $2, %%cx\n"
" divw %%cx\n"
" movl $0, %%eax\n"
" jnz 1f\n"
" movl $1, %%eax\n"
"1:\n"
: "=a" (ret) : : "cx", "dx");
return ret;
}
#endif
static bool has_cpuid(void)
{
return flag_is_changeable_p(X86_EFLAGS_ID);
}
static bool has_mtrr(void)
{
return cpuid_edx(0x00000001) & (1 << 12) ? true : false;
}
#ifndef CONFIG_TPL_BUILD
static int build_vendor_name(char *vendor_name)
{
struct cpuid_result result;
result = cpuid(0x00000000);
unsigned int *name_as_ints = (unsigned int *)vendor_name;
name_as_ints[0] = result.ebx;
name_as_ints[1] = result.edx;
name_as_ints[2] = result.ecx;
return result.eax;
}
#endif
static void identify_cpu(struct cpu_device_id *cpu)
{
cpu->device = 0; /* fix gcc 4.4.4 warning */
/*
* Do a quick and dirty check to save space - Intel and AMD only and
* just the vendor. This is enough for most TPL code.
*/
if (spl_phase() == PHASE_TPL) {
struct cpuid_result result;
result = cpuid(0x00000000);
switch (result.ecx >> 24) {
case 'l': /* GenuineIntel */
cpu->vendor = X86_VENDOR_INTEL;
break;
case 'D': /* AuthenticAMD */
cpu->vendor = X86_VENDOR_AMD;
break;
default:
cpu->vendor = X86_VENDOR_ANY;
break;
}
return;
}
/* gcc 7.3 does not want to drop x86_vendors, so use #ifdef */
#ifndef CONFIG_TPL_BUILD
char vendor_name[16];
int i;
vendor_name[0] = '\0'; /* Unset */
/* Find the id and vendor_name */
if (!has_cpuid()) {
/* Its a 486 if we can modify the AC flag */
if (flag_is_changeable_p(X86_EFLAGS_AC))
cpu->device = 0x00000400; /* 486 */
else
cpu->device = 0x00000300; /* 386 */
if ((cpu->device == 0x00000400) && test_cyrix_52div()) {
memcpy(vendor_name, "CyrixInstead", 13);
/* If we ever care we can enable cpuid here */
}
/* Detect NexGen with old hypercode */
else if (deep_magic_nexgen_probe())
memcpy(vendor_name, "NexGenDriven", 13);
} else {
int cpuid_level;
cpuid_level = build_vendor_name(vendor_name);
vendor_name[12] = '\0';
/* Intel-defined flags: level 0x00000001 */
if (cpuid_level >= 0x00000001) {
cpu->device = cpuid_eax(0x00000001);
} else {
/* Have CPUID level 0 only unheard of */
cpu->device = 0x00000400;
}
}
cpu->vendor = X86_VENDOR_UNKNOWN;
for (i = 0; i < ARRAY_SIZE(x86_vendors); i++) {
if (memcmp(vendor_name, x86_vendors[i].name, 12) == 0) {
cpu->vendor = x86_vendors[i].vendor;
break;
}
}
#endif
}
static inline void get_fms(struct cpuinfo_x86 *c, uint32_t tfms)
{
c->x86 = (tfms >> 8) & 0xf;
c->x86_model = (tfms >> 4) & 0xf;
c->x86_mask = tfms & 0xf;
if (c->x86 == 0xf)
c->x86 += (tfms >> 20) & 0xff;
if (c->x86 >= 0x6)
c->x86_model += ((tfms >> 16) & 0xF) << 4;
}
u32 cpu_get_family_model(void)
{
return gd->arch.x86_device & 0x0fff0ff0;
}
u32 cpu_get_stepping(void)
{
return gd->arch.x86_mask;
}
/* initialise FPU, reset EM, set MP and NE */
static void setup_cpu_features(void)
{
const u32 em_rst = ~X86_CR0_EM;
const u32 mp_ne_set = X86_CR0_MP | X86_CR0_NE;
asm ("fninit\n" \
"movl %%cr0, %%eax\n" \
"andl %0, %%eax\n" \
"orl %1, %%eax\n" \
"movl %%eax, %%cr0\n" \
: : "i" (em_rst), "i" (mp_ne_set) : "eax");
}
static void setup_identity(void)
{
/* identify CPU via cpuid and store the decoded info into gd->arch */
if (has_cpuid()) {
struct cpu_device_id cpu;
struct cpuinfo_x86 c;
identify_cpu(&cpu);
get_fms(&c, cpu.device);
gd->arch.x86 = c.x86;
gd->arch.x86_vendor = cpu.vendor;
gd->arch.x86_model = c.x86_model;
gd->arch.x86_mask = c.x86_mask;
gd->arch.x86_device = cpu.device;
gd->arch.has_mtrr = has_mtrr();
}
}
/* Don't allow PCI region 3 to use memory in the 2-4GB memory hole */
static void setup_pci_ram_top(void)
{
gd->pci_ram_top = 0x80000000U;
}
static void setup_mtrr(void)
{
u64 mtrr_cap;
/* Configure fixed range MTRRs for some legacy regions */
if (!gd->arch.has_mtrr)
return;
mtrr_cap = native_read_msr(MTRR_CAP_MSR);
if (mtrr_cap & MTRR_CAP_FIX) {
/* Mark the VGA RAM area as uncacheable */
native_write_msr(MTRR_FIX_16K_A0000_MSR,
MTRR_FIX_TYPE(MTRR_TYPE_UNCACHEABLE),
MTRR_FIX_TYPE(MTRR_TYPE_UNCACHEABLE));
/*
* Mark the PCI ROM area as cacheable to improve ROM
* execution performance.
*/
native_write_msr(MTRR_FIX_4K_C0000_MSR,
MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
native_write_msr(MTRR_FIX_4K_C8000_MSR,
MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
native_write_msr(MTRR_FIX_4K_D0000_MSR,
MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
native_write_msr(MTRR_FIX_4K_D8000_MSR,
MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
/* Enable the fixed range MTRRs */
msr_setbits_64(MTRR_DEF_TYPE_MSR, MTRR_DEF_TYPE_FIX_EN);
}
}
int x86_cpu_init_tpl(void)
{
setup_cpu_features();
setup_identity();
return 0;
}
int x86_cpu_init_f(void)
{
if (ll_boot_init())
setup_cpu_features();
setup_identity();
setup_mtrr();
setup_pci_ram_top();
/* Set up the i8254 timer if required */
if (IS_ENABLED(CONFIG_I8254_TIMER))
i8254_init();
return 0;
}
int x86_cpu_reinit_f(void)
{
setup_identity();
setup_pci_ram_top();
if (locate_coreboot_table() >= 0)
gd->flags |= GD_FLG_SKIP_LL_INIT;
return 0;
}
void x86_enable_caches(void)
{
unsigned long cr0;
cr0 = read_cr0();
cr0 &= ~(X86_CR0_NW | X86_CR0_CD);
write_cr0(cr0);
wbinvd();
}
void enable_caches(void) __attribute__((weak, alias("x86_enable_caches")));
void x86_disable_caches(void)
{
unsigned long cr0;
cr0 = read_cr0();
cr0 |= X86_CR0_NW | X86_CR0_CD;
wbinvd();
write_cr0(cr0);
wbinvd();
}
void disable_caches(void) __attribute__((weak, alias("x86_disable_caches")));
int dcache_status(void)
{
return !(read_cr0() & X86_CR0_CD);
}
void cpu_enable_paging_pae(ulong cr3)
{
__asm__ __volatile__(
/* Load the page table address */
"movl %0, %%cr3\n"
/* Enable pae */
"movl %%cr4, %%eax\n"
"orl $0x00000020, %%eax\n"
"movl %%eax, %%cr4\n"
/* Enable paging */
"movl %%cr0, %%eax\n"
"orl $0x80000000, %%eax\n"
"movl %%eax, %%cr0\n"
:
: "r" (cr3)
: "eax");
}
void cpu_disable_paging_pae(void)
{
/* Turn off paging */
__asm__ __volatile__ (
/* Disable paging */
"movl %%cr0, %%eax\n"
"andl $0x7fffffff, %%eax\n"
"movl %%eax, %%cr0\n"
/* Disable pae */
"movl %%cr4, %%eax\n"
"andl $0xffffffdf, %%eax\n"
"movl %%eax, %%cr4\n"
:
:
: "eax");
}
static bool can_detect_long_mode(void)
{
return cpuid_eax(0x80000000) > 0x80000000UL;
}
static bool has_long_mode(void)
{
return cpuid_edx(0x80000001) & (1 << 29) ? true : false;
}
int cpu_has_64bit(void)
{
return has_cpuid() && can_detect_long_mode() &&
has_long_mode();
}
#define PAGETABLE_BASE 0x80000
#define PAGETABLE_SIZE (6 * 4096)
/**
* build_pagetable() - build a flat 4GiB page table structure for 64-bti mode
*
* @pgtable: Pointer to a 24iKB block of memory
*/
static void build_pagetable(uint32_t *pgtable)
{
uint i;
memset(pgtable, '\0', PAGETABLE_SIZE);
/* Level 4 needs a single entry */
pgtable[0] = (ulong)&pgtable[1024] + 7;
/* Level 3 has one 64-bit entry for each GiB of memory */
for (i = 0; i < 4; i++)
pgtable[1024 + i * 2] = (ulong)&pgtable[2048] + 0x1000 * i + 7;
/* Level 2 has 2048 64-bit entries, each repesenting 2MiB */
for (i = 0; i < 2048; i++)
pgtable[2048 + i * 2] = 0x183 + (i << 21UL);
}
int cpu_jump_to_64bit(ulong setup_base, ulong target)
{
uint32_t *pgtable;
pgtable = memalign(4096, PAGETABLE_SIZE);
if (!pgtable)
return -ENOMEM;
build_pagetable(pgtable);
cpu_call64((ulong)pgtable, setup_base, target);
free(pgtable);
return -EFAULT;
}
/*
* Jump from SPL to U-Boot
*
* This function is work-in-progress with many issues to resolve.
*
* It works by setting up several regions:
* ptr - a place to put the code that jumps into 64-bit mode
* gdt - a place to put the global descriptor table
* pgtable - a place to put the page tables
*
* The cpu_call64() code is copied from ROM and then manually patched so that
* it has the correct GDT address in RAM. U-Boot is copied from ROM into
* its pre-relocation address. Then we jump to the cpu_call64() code in RAM,
* which changes to 64-bit mode and starts U-Boot.
*/
int cpu_jump_to_64bit_uboot(ulong target)
{
typedef void (*func_t)(ulong pgtable, ulong setup_base, ulong target);
uint32_t *pgtable;
func_t func;
char *ptr;
pgtable = (uint32_t *)PAGETABLE_BASE;
build_pagetable(pgtable);
extern long call64_stub_size;
ptr = malloc(call64_stub_size);
if (!ptr) {
printf("Failed to allocate the cpu_call64 stub\n");
return -ENOMEM;
}
memcpy(ptr, cpu_call64, call64_stub_size);
func = (func_t)ptr;
/* Jump to U-Boot */
func((ulong)pgtable, 0, (ulong)target);
return -EFAULT;
}
#ifdef CONFIG_SMP
static int enable_smis(struct udevice *cpu, void *unused)
{
return 0;
}
static struct mp_flight_record mp_steps[] = {
MP_FR_BLOCK_APS(mp_init_cpu, NULL, mp_init_cpu, NULL),
/* Wait for APs to finish initialization before proceeding */
MP_FR_BLOCK_APS(NULL, NULL, enable_smis, NULL),
};
int x86_mp_init(void)
{
struct mp_params mp_params;
mp_params.parallel_microcode_load = 0,
mp_params.flight_plan = &mp_steps[0];
mp_params.num_records = ARRAY_SIZE(mp_steps);
mp_params.microcode_pointer = 0;
if (mp_init(&mp_params)) {
printf("Warning: MP init failure\n");
return -EIO;
}
return 0;
}
#endif