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 * See file CREDITS for list of people who contributed to this 17 * project. 18 * 19 * This program is free software; you can redistribute it and/or 20 * modify it under the terms of the GNU General Public License as 21 * published by the Free Software Foundation; either version 2 of 22 * the License, or (at your option) any later version. 23 * 24 * This program is distributed in the hope that it will be useful, 25 * but WITHOUT ANY WARRANTY; without even the implied warranty of 26 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 27 * GNU General Public License for more details. 28 * 29 * You should have received a copy of the GNU General Public License 30 * along with this program; if not, write to the Free Software 31 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 32 * MA 02111-1307 USA 33 */ 34 35 #include <common.h> 36 #include <command.h> 37 #include <asm/control_regs.h> 38 #include <asm/processor.h> 39 #include <asm/processor-flags.h> 40 #include <asm/interrupt.h> 41 #include <linux/compiler.h> 42 43 /* 44 * Constructor for a conventional segment GDT (or LDT) entry 45 * This is a macro so it can be used in initialisers 46 */ 47 #define GDT_ENTRY(flags, base, limit) \ 48 ((((base) & 0xff000000ULL) << (56-24)) | \ 49 (((flags) & 0x0000f0ffULL) << 40) | \ 50 (((limit) & 0x000f0000ULL) << (48-16)) | \ 51 (((base) & 0x00ffffffULL) << 16) | \ 52 (((limit) & 0x0000ffffULL))) 53 54 struct gdt_ptr { 55 u16 len; 56 u32 ptr; 57 } __packed; 58 59 static void load_ds(u32 segment) 60 { 61 asm volatile("movl %0, %%ds" : : "r" (segment * X86_GDT_ENTRY_SIZE)); 62 } 63 64 static void load_es(u32 segment) 65 { 66 asm volatile("movl %0, %%es" : : "r" (segment * X86_GDT_ENTRY_SIZE)); 67 } 68 69 static void load_fs(u32 segment) 70 { 71 asm volatile("movl %0, %%fs" : : "r" (segment * X86_GDT_ENTRY_SIZE)); 72 } 73 74 static void load_gs(u32 segment) 75 { 76 asm volatile("movl %0, %%gs" : : "r" (segment * X86_GDT_ENTRY_SIZE)); 77 } 78 79 static void load_ss(u32 segment) 80 { 81 asm volatile("movl %0, %%ss" : : "r" (segment * X86_GDT_ENTRY_SIZE)); 82 } 83 84 static void load_gdt(const u64 *boot_gdt, u16 num_entries) 85 { 86 struct gdt_ptr gdt; 87 88 gdt.len = (num_entries * 8) - 1; 89 gdt.ptr = (u32)boot_gdt; 90 91 asm volatile("lgdtl %0\n" : : "m" (gdt)); 92 } 93 94 void setup_gdt(gd_t *id, u64 *gdt_addr) 95 { 96 /* CS: code, read/execute, 4 GB, base 0 */ 97 gdt_addr[X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff); 98 99 /* DS: data, read/write, 4 GB, base 0 */ 100 gdt_addr[X86_GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff); 101 102 /* FS: data, read/write, 4 GB, base (Global Data Pointer) */ 103 gdt_addr[X86_GDT_ENTRY_32BIT_FS] = GDT_ENTRY(0xc093, (ulong)id, 0xfffff); 104 105 /* 16-bit CS: code, read/execute, 64 kB, base 0 */ 106 gdt_addr[X86_GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x109b, 0, 0x0ffff); 107 108 /* 16-bit DS: data, read/write, 64 kB, base 0 */ 109 gdt_addr[X86_GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x1093, 0, 0x0ffff); 110 111 load_gdt(gdt_addr, X86_GDT_NUM_ENTRIES); 112 load_ds(X86_GDT_ENTRY_32BIT_DS); 113 load_es(X86_GDT_ENTRY_32BIT_DS); 114 load_gs(X86_GDT_ENTRY_32BIT_DS); 115 load_ss(X86_GDT_ENTRY_32BIT_DS); 116 load_fs(X86_GDT_ENTRY_32BIT_FS); 117 } 118 119 int __weak x86_cleanup_before_linux(void) 120 { 121 return 0; 122 } 123 124 int x86_cpu_init_f(void) 125 { 126 const u32 em_rst = ~X86_CR0_EM; 127 const u32 mp_ne_set = X86_CR0_MP | X86_CR0_NE; 128 129 /* initialize FPU, reset EM, set MP and NE */ 130 asm ("fninit\n" \ 131 "movl %%cr0, %%eax\n" \ 132 "andl %0, %%eax\n" \ 133 "orl %1, %%eax\n" \ 134 "movl %%eax, %%cr0\n" \ 135 : : "i" (em_rst), "i" (mp_ne_set) : "eax"); 136 137 return 0; 138 } 139 int cpu_init_f(void) __attribute__((weak, alias("x86_cpu_init_f"))); 140 141 int x86_cpu_init_r(void) 142 { 143 /* Initialize core interrupt and exception functionality of CPU */ 144 cpu_init_interrupts(); 145 return 0; 146 } 147 int cpu_init_r(void) __attribute__((weak, alias("x86_cpu_init_r"))); 148 149 void x86_enable_caches(void) 150 { 151 unsigned long cr0; 152 153 cr0 = read_cr0(); 154 cr0 &= ~(X86_CR0_NW | X86_CR0_CD); 155 write_cr0(cr0); 156 wbinvd(); 157 } 158 void enable_caches(void) __attribute__((weak, alias("x86_enable_caches"))); 159 160 void x86_disable_caches(void) 161 { 162 unsigned long cr0; 163 164 cr0 = read_cr0(); 165 cr0 |= X86_CR0_NW | X86_CR0_CD; 166 wbinvd(); 167 write_cr0(cr0); 168 wbinvd(); 169 } 170 void disable_caches(void) __attribute__((weak, alias("x86_disable_caches"))); 171 172 int x86_init_cache(void) 173 { 174 enable_caches(); 175 176 return 0; 177 } 178 int init_cache(void) __attribute__((weak, alias("x86_init_cache"))); 179 180 int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) 181 { 182 printf("resetting ...\n"); 183 184 /* wait 50 ms */ 185 udelay(50000); 186 disable_interrupts(); 187 reset_cpu(0); 188 189 /*NOTREACHED*/ 190 return 0; 191 } 192 193 void flush_cache(unsigned long dummy1, unsigned long dummy2) 194 { 195 asm("wbinvd\n"); 196 } 197 198 void __attribute__ ((regparm(0))) generate_gpf(void); 199 200 /* segment 0x70 is an arbitrary segment which does not exist */ 201 asm(".globl generate_gpf\n" 202 ".hidden generate_gpf\n" 203 ".type generate_gpf, @function\n" 204 "generate_gpf:\n" 205 "ljmp $0x70, $0x47114711\n"); 206 207 void __reset_cpu(ulong addr) 208 { 209 printf("Resetting using x86 Triple Fault\n"); 210 set_vector(13, generate_gpf); /* general protection fault handler */ 211 set_vector(8, generate_gpf); /* double fault handler */ 212 generate_gpf(); /* start the show */ 213 } 214 void reset_cpu(ulong addr) __attribute__((weak, alias("__reset_cpu"))); 215 216 int dcache_status(void) 217 { 218 return !(read_cr0() & 0x40000000); 219 } 220 221 /* Define these functions to allow ehch-hcd to function */ 222 void flush_dcache_range(unsigned long start, unsigned long stop) 223 { 224 } 225 226 void invalidate_dcache_range(unsigned long start, unsigned long stop) 227 { 228 } 229