1/* 2 * IA32 helper functions 3 * 4 * Copyright (C) 1999 Arun Sharma <arun.sharma@intel.com> 5 * Copyright (C) 2000 Asit K. Mallick <asit.k.mallick@intel.com> 6 * Copyright (C) 2001-2002 Hewlett-Packard Co 7 * David Mosberger-Tang <davidm@hpl.hp.com> 8 * 9 * 06/16/00 A. Mallick added csd/ssd/tssd for ia32 thread context 10 * 02/19/01 D. Mosberger dropped tssd; it's not needed 11 * 09/14/01 D. Mosberger fixed memory management for gdt/tss page 12 * 09/29/01 D. Mosberger added ia32_load_segment_descriptors() 13 */ 14 15#include <linux/kernel.h> 16#include <linux/init.h> 17#include <linux/mm.h> 18#include <linux/personality.h> 19#include <linux/sched.h> 20 21#include <asm/intrinsics.h> 22#include <asm/page.h> 23#include <asm/pgtable.h> 24#include <asm/system.h> 25#include <asm/processor.h> 26#include <asm/uaccess.h> 27 28#include "ia32priv.h" 29 30extern void die_if_kernel (char *str, struct pt_regs *regs, long err); 31 32struct exec_domain ia32_exec_domain; 33struct page *ia32_shared_page[NR_CPUS]; 34unsigned long *ia32_boot_gdt; 35unsigned long *cpu_gdt_table[NR_CPUS]; 36struct page *ia32_gate_page; 37 38static unsigned long 39load_desc (u16 selector) 40{ 41 unsigned long *table, limit, index; 42 43 if (!selector) 44 return 0; 45 if (selector & IA32_SEGSEL_TI) { 46 table = (unsigned long *) IA32_LDT_OFFSET; 47 limit = IA32_LDT_ENTRIES; 48 } else { 49 table = cpu_gdt_table[smp_processor_id()]; 50 limit = IA32_PAGE_SIZE / sizeof(ia32_boot_gdt[0]); 51 } 52 index = selector >> IA32_SEGSEL_INDEX_SHIFT; 53 if (index >= limit) 54 return 0; 55 return IA32_SEG_UNSCRAMBLE(table[index]); 56} 57 58void 59ia32_load_segment_descriptors (struct task_struct *task) 60{ 61 struct pt_regs *regs = task_pt_regs(task); 62 63 /* Setup the segment descriptors */ 64 regs->r24 = load_desc(regs->r16 >> 16); /* ESD */ 65 regs->r27 = load_desc(regs->r16 >> 0); /* DSD */ 66 regs->r28 = load_desc(regs->r16 >> 32); /* FSD */ 67 regs->r29 = load_desc(regs->r16 >> 48); /* GSD */ 68 regs->ar_csd = load_desc(regs->r17 >> 0); /* CSD */ 69 regs->ar_ssd = load_desc(regs->r17 >> 16); /* SSD */ 70} 71 72int 73ia32_clone_tls (struct task_struct *child, struct pt_regs *childregs) 74{ 75 struct desc_struct *desc; 76 struct ia32_user_desc info; 77 int idx; 78 79 if (copy_from_user(&info, (void __user *)(childregs->r14 & 0xffffffff), sizeof(info))) 80 return -EFAULT; 81 if (LDT_empty(&info)) 82 return -EINVAL; 83 84 idx = info.entry_number; 85 if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX) 86 return -EINVAL; 87 88 desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN; 89 desc->a = LDT_entry_a(&info); 90 desc->b = LDT_entry_b(&info); 91 92 load_TLS(&child->thread, smp_processor_id()); 93 ia32_load_segment_descriptors(child); 94 load_TLS(¤t->thread, smp_processor_id()); 95 96 return 0; 97} 98 99void 100ia32_save_state (struct task_struct *t) 101{ 102 t->thread.eflag = ia64_getreg(_IA64_REG_AR_EFLAG); 103 t->thread.fsr = ia64_getreg(_IA64_REG_AR_FSR); 104 t->thread.fcr = ia64_getreg(_IA64_REG_AR_FCR); 105 t->thread.fir = ia64_getreg(_IA64_REG_AR_FIR); 106 t->thread.fdr = ia64_getreg(_IA64_REG_AR_FDR); 107 ia64_set_kr(IA64_KR_IO_BASE, t->thread.old_iob); 108 ia64_set_kr(IA64_KR_TSSD, t->thread.old_k1); 109} 110 111void 112ia32_load_state (struct task_struct *t) 113{ 114 unsigned long eflag, fsr, fcr, fir, fdr, tssd; 115 struct pt_regs *regs = task_pt_regs(t); 116 117 eflag = t->thread.eflag; 118 fsr = t->thread.fsr; 119 fcr = t->thread.fcr; 120 fir = t->thread.fir; 121 fdr = t->thread.fdr; 122 tssd = load_desc(_TSS); /* TSSD */ 123 124 ia64_setreg(_IA64_REG_AR_EFLAG, eflag); 125 ia64_setreg(_IA64_REG_AR_FSR, fsr); 126 ia64_setreg(_IA64_REG_AR_FCR, fcr); 127 ia64_setreg(_IA64_REG_AR_FIR, fir); 128 ia64_setreg(_IA64_REG_AR_FDR, fdr); 129 current->thread.old_iob = ia64_get_kr(IA64_KR_IO_BASE); 130 current->thread.old_k1 = ia64_get_kr(IA64_KR_TSSD); 131 ia64_set_kr(IA64_KR_IO_BASE, IA32_IOBASE); 132 ia64_set_kr(IA64_KR_TSSD, tssd); 133 134 regs->r17 = (_TSS << 48) | (_LDT << 32) | (__u32) regs->r17; 135 regs->r30 = load_desc(_LDT); /* LDTD */ 136 load_TLS(&t->thread, smp_processor_id()); 137} 138 139/* 140 * Setup IA32 GDT and TSS 141 */ 142void 143ia32_gdt_init (void) 144{ 145 int cpu = smp_processor_id(); 146 147 ia32_shared_page[cpu] = alloc_page(GFP_KERNEL); 148 if (!ia32_shared_page[cpu]) 149 panic("failed to allocate ia32_shared_page[%d]\n", cpu); 150 151 cpu_gdt_table[cpu] = page_address(ia32_shared_page[cpu]); 152 153 /* Copy from the boot cpu's GDT */ 154 memcpy(cpu_gdt_table[cpu], ia32_boot_gdt, PAGE_SIZE); 155} 156 157 158/* 159 * Setup IA32 GDT and TSS 160 */ 161static void 162ia32_boot_gdt_init (void) 163{ 164 unsigned long ldt_size; 165 166 ia32_shared_page[0] = alloc_page(GFP_KERNEL); 167 if (!ia32_shared_page[0]) 168 panic("failed to allocate ia32_shared_page[0]\n"); 169 170 ia32_boot_gdt = page_address(ia32_shared_page[0]); 171 cpu_gdt_table[0] = ia32_boot_gdt; 172 173 /* CS descriptor in IA-32 (scrambled) format */ 174 ia32_boot_gdt[__USER_CS >> 3] 175 = IA32_SEG_DESCRIPTOR(0, (IA32_GATE_END-1) >> IA32_PAGE_SHIFT, 176 0xb, 1, 3, 1, 1, 1, 1); 177 178 /* DS descriptor in IA-32 (scrambled) format */ 179 ia32_boot_gdt[__USER_DS >> 3] 180 = IA32_SEG_DESCRIPTOR(0, (IA32_GATE_END-1) >> IA32_PAGE_SHIFT, 181 0x3, 1, 3, 1, 1, 1, 1); 182 183 ldt_size = PAGE_ALIGN(IA32_LDT_ENTRIES*IA32_LDT_ENTRY_SIZE); 184 ia32_boot_gdt[TSS_ENTRY] = IA32_SEG_DESCRIPTOR(IA32_TSS_OFFSET, 235, 185 0xb, 0, 3, 1, 1, 1, 0); 186 ia32_boot_gdt[LDT_ENTRY] = IA32_SEG_DESCRIPTOR(IA32_LDT_OFFSET, ldt_size - 1, 187 0x2, 0, 3, 1, 1, 1, 0); 188} 189 190static void 191ia32_gate_page_init(void) 192{ 193 unsigned long *sr; 194 195 ia32_gate_page = alloc_page(GFP_KERNEL); 196 sr = page_address(ia32_gate_page); 197 /* This is popl %eax ; movl $,%eax ; int $0x80 */ 198 *sr++ = 0xb858 | (__IA32_NR_sigreturn << 16) | (0x80cdUL << 48); 199 200 /* This is movl $,%eax ; int $0x80 */ 201 *sr = 0xb8 | (__IA32_NR_rt_sigreturn << 8) | (0x80cdUL << 40); 202} 203 204void 205ia32_mem_init(void) 206{ 207 ia32_boot_gdt_init(); 208 ia32_gate_page_init(); 209} 210 211/* 212 * Handle bad IA32 interrupt via syscall 213 */ 214void 215ia32_bad_interrupt (unsigned long int_num, struct pt_regs *regs) 216{ 217 siginfo_t siginfo; 218 219 die_if_kernel("Bad IA-32 interrupt", regs, int_num); 220 221 siginfo.si_signo = SIGTRAP; 222 siginfo.si_errno = int_num; 223 siginfo.si_flags = 0; 224 siginfo.si_isr = 0; 225 siginfo.si_addr = NULL; 226 siginfo.si_imm = 0; 227 siginfo.si_code = TRAP_BRKPT; 228 force_sig_info(SIGTRAP, &siginfo, current); 229} 230 231void 232ia32_cpu_init (void) 233{ 234 /* initialize global ia32 state - CR0 and CR4 */ 235 ia64_setreg(_IA64_REG_AR_CFLAG, (((ulong) IA32_CR4 << 32) | IA32_CR0)); 236} 237 238static int __init 239ia32_init (void) 240{ 241 ia32_exec_domain.name = "Linux/x86"; 242 ia32_exec_domain.handler = NULL; 243 ia32_exec_domain.pers_low = PER_LINUX32; 244 ia32_exec_domain.pers_high = PER_LINUX32; 245 ia32_exec_domain.signal_map = default_exec_domain.signal_map; 246 ia32_exec_domain.signal_invmap = default_exec_domain.signal_invmap; 247 register_exec_domain(&ia32_exec_domain); 248 249#if PAGE_SHIFT > IA32_PAGE_SHIFT 250 { 251 extern struct kmem_cache *partial_page_cachep; 252 253 partial_page_cachep = kmem_cache_create("partial_page_cache", 254 sizeof(struct partial_page), 255 0, SLAB_PANIC, NULL, NULL); 256 } 257#endif 258 return 0; 259} 260 261__initcall(ia32_init); 262