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 * SPDX-License-Identifier: GPL-2.0+
21 #include <asm/control_regs.h>
22 #include <asm/processor.h>
23 #include <asm/processor-flags.h>
24 #include <asm/interrupt.h>
25 #include <linux/compiler.h>
28 * Constructor for a conventional segment GDT (or LDT) entry
29 * This is a macro so it can be used in initialisers
31 #define GDT_ENTRY(flags, base, limit) \
32 ((((base) & 0xff000000ULL) << (56-24)) | \
33 (((flags) & 0x0000f0ffULL) << 40) | \
34 (((limit) & 0x000f0000ULL) << (48-16)) | \
35 (((base) & 0x00ffffffULL) << 16) | \
36 (((limit) & 0x0000ffffULL)))
43 static void load_ds(u32 segment)
45 asm volatile("movl %0, %%ds" : : "r" (segment * X86_GDT_ENTRY_SIZE));
48 static void load_es(u32 segment)
50 asm volatile("movl %0, %%es" : : "r" (segment * X86_GDT_ENTRY_SIZE));
53 static void load_fs(u32 segment)
55 asm volatile("movl %0, %%fs" : : "r" (segment * X86_GDT_ENTRY_SIZE));
58 static void load_gs(u32 segment)
60 asm volatile("movl %0, %%gs" : : "r" (segment * X86_GDT_ENTRY_SIZE));
63 static void load_ss(u32 segment)
65 asm volatile("movl %0, %%ss" : : "r" (segment * X86_GDT_ENTRY_SIZE));
68 static void load_gdt(const u64 *boot_gdt, u16 num_entries)
72 gdt.len = (num_entries * 8) - 1;
73 gdt.ptr = (u32)boot_gdt;
75 asm volatile("lgdtl %0\n" : : "m" (gdt));
78 void setup_gdt(gd_t *id, u64 *gdt_addr)
80 /* CS: code, read/execute, 4 GB, base 0 */
81 gdt_addr[X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff);
83 /* DS: data, read/write, 4 GB, base 0 */
84 gdt_addr[X86_GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff);
86 /* FS: data, read/write, 4 GB, base (Global Data Pointer) */
87 id->arch.gd_addr = id;
88 gdt_addr[X86_GDT_ENTRY_32BIT_FS] = GDT_ENTRY(0xc093,
89 (ulong)&id->arch.gd_addr, 0xfffff);
91 /* 16-bit CS: code, read/execute, 64 kB, base 0 */
92 gdt_addr[X86_GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x109b, 0, 0x0ffff);
94 /* 16-bit DS: data, read/write, 64 kB, base 0 */
95 gdt_addr[X86_GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x1093, 0, 0x0ffff);
97 load_gdt(gdt_addr, X86_GDT_NUM_ENTRIES);
98 load_ds(X86_GDT_ENTRY_32BIT_DS);
99 load_es(X86_GDT_ENTRY_32BIT_DS);
100 load_gs(X86_GDT_ENTRY_32BIT_DS);
101 load_ss(X86_GDT_ENTRY_32BIT_DS);
102 load_fs(X86_GDT_ENTRY_32BIT_FS);
105 int __weak x86_cleanup_before_linux(void)
107 #ifdef CONFIG_BOOTSTAGE_STASH
108 bootstage_stash((void *)CONFIG_BOOTSTAGE_STASH,
109 CONFIG_BOOTSTAGE_STASH_SIZE);
115 int x86_cpu_init_f(void)
117 const u32 em_rst = ~X86_CR0_EM;
118 const u32 mp_ne_set = X86_CR0_MP | X86_CR0_NE;
120 /* initialize FPU, reset EM, set MP and NE */
122 "movl %%cr0, %%eax\n" \
125 "movl %%eax, %%cr0\n" \
126 : : "i" (em_rst), "i" (mp_ne_set) : "eax");
130 int cpu_init_f(void) __attribute__((weak, alias("x86_cpu_init_f")));
132 int x86_cpu_init_r(void)
134 /* Initialize core interrupt and exception functionality of CPU */
135 cpu_init_interrupts();
138 int cpu_init_r(void) __attribute__((weak, alias("x86_cpu_init_r")));
140 void x86_enable_caches(void)
145 cr0 &= ~(X86_CR0_NW | X86_CR0_CD);
149 void enable_caches(void) __attribute__((weak, alias("x86_enable_caches")));
151 void x86_disable_caches(void)
156 cr0 |= X86_CR0_NW | X86_CR0_CD;
161 void disable_caches(void) __attribute__((weak, alias("x86_disable_caches")));
163 int x86_init_cache(void)
169 int init_cache(void) __attribute__((weak, alias("x86_init_cache")));
171 int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
173 printf("resetting ...\n");
177 disable_interrupts();
184 void flush_cache(unsigned long dummy1, unsigned long dummy2)
189 void __attribute__ ((regparm(0))) generate_gpf(void);
191 /* segment 0x70 is an arbitrary segment which does not exist */
192 asm(".globl generate_gpf\n"
193 ".hidden generate_gpf\n"
194 ".type generate_gpf, @function\n"
196 "ljmp $0x70, $0x47114711\n");
198 void __reset_cpu(ulong addr)
200 printf("Resetting using x86 Triple Fault\n");
201 set_vector(13, generate_gpf); /* general protection fault handler */
202 set_vector(8, generate_gpf); /* double fault handler */
203 generate_gpf(); /* start the show */
205 void reset_cpu(ulong addr) __attribute__((weak, alias("__reset_cpu")));
207 int dcache_status(void)
209 return !(read_cr0() & 0x40000000);
212 /* Define these functions to allow ehch-hcd to function */
213 void flush_dcache_range(unsigned long start, unsigned long stop)
217 void invalidate_dcache_range(unsigned long start, unsigned long stop)
221 void dcache_enable(void)
226 void dcache_disable(void)
231 void icache_enable(void)
235 void icache_disable(void)
239 int icache_status(void)