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/*
* (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>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <command.h>
#include <asm/control_regs.h>
#include <asm/processor.h>
#include <asm/processor-flags.h>
#include <asm/interrupt.h>
#include <linux/compiler.h>
/*
* 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;
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 * 8) - 1;
gdt.ptr = (u32)boot_gdt;
asm volatile("lgdtl %0\n" : : "m" (gdt));
}
void setup_gdt(gd_t *id, u64 *gdt_addr)
{
/* CS: code, read/execute, 4 GB, base 0 */
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, 4 GB, base (Global Data Pointer) */
id->arch.gd_addr = id;
gdt_addr[X86_GDT_ENTRY_32BIT_FS] = GDT_ENTRY(0xc093,
(ulong)&id->arch.gd_addr, 0xfffff);
/* 16-bit CS: code, read/execute, 64 kB, base 0 */
gdt_addr[X86_GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x109b, 0, 0x0ffff);
/* 16-bit DS: data, read/write, 64 kB, base 0 */
gdt_addr[X86_GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x1093, 0, 0x0ffff);
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);
}
int __weak x86_cleanup_before_linux(void)
{
#ifdef CONFIG_BOOTSTAGE_STASH
bootstage_stash((void *)CONFIG_BOOTSTAGE_STASH,
CONFIG_BOOTSTAGE_STASH_SIZE);
#endif
return 0;
}
int x86_cpu_init_f(void)
{
const u32 em_rst = ~X86_CR0_EM;
const u32 mp_ne_set = X86_CR0_MP | X86_CR0_NE;
/* initialize FPU, reset EM, set MP and 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");
return 0;
}
int cpu_init_f(void) __attribute__((weak, alias("x86_cpu_init_f")));
int x86_cpu_init_r(void)
{
/* Initialize core interrupt and exception functionality of CPU */
cpu_init_interrupts();
return 0;
}
int cpu_init_r(void) __attribute__((weak, alias("x86_cpu_init_r")));
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 x86_init_cache(void)
{
enable_caches();
return 0;
}
int init_cache(void) __attribute__((weak, alias("x86_init_cache")));
int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
printf("resetting ...\n");
/* wait 50 ms */
udelay(50000);
disable_interrupts();
reset_cpu(0);
/*NOTREACHED*/
return 0;
}
void flush_cache(unsigned long dummy1, unsigned long dummy2)
{
asm("wbinvd\n");
}
void __attribute__ ((regparm(0))) generate_gpf(void);
/* segment 0x70 is an arbitrary segment which does not exist */
asm(".globl generate_gpf\n"
".hidden generate_gpf\n"
".type generate_gpf, @function\n"
"generate_gpf:\n"
"ljmp $0x70, $0x47114711\n");
void __reset_cpu(ulong addr)
{
printf("Resetting using x86 Triple Fault\n");
set_vector(13, generate_gpf); /* general protection fault handler */
set_vector(8, generate_gpf); /* double fault handler */
generate_gpf(); /* start the show */
}
void reset_cpu(ulong addr) __attribute__((weak, alias("__reset_cpu")));
int dcache_status(void)
{
return !(read_cr0() & 0x40000000);
}
/* Define these functions to allow ehch-hcd to function */
void flush_dcache_range(unsigned long start, unsigned long stop)
{
}
void invalidate_dcache_range(unsigned long start, unsigned long stop)
{
}
void dcache_enable(void)
{
enable_caches();
}
void dcache_disable(void)
{
disable_caches();
}
void icache_enable(void)
{
}
void icache_disable(void)
{
}
int icache_status(void)
{
return 1;
}
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