1 /*---------------------------------------------------------------------------+ 2 | fpu_system.h | 3 | | 4 | Copyright (C) 1992,1994,1997 | 5 | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, | 6 | Australia. E-mail billm@suburbia.net | 7 | | 8 +---------------------------------------------------------------------------*/ 9 10 #ifndef _FPU_SYSTEM_H 11 #define _FPU_SYSTEM_H 12 13 /* system dependent definitions */ 14 15 #include <linux/sched.h> 16 #include <linux/kernel.h> 17 #include <linux/mm.h> 18 19 #include <asm/desc.h> 20 #include <asm/mmu_context.h> 21 22 static inline struct desc_struct FPU_get_ldt_descriptor(unsigned seg) 23 { 24 static struct desc_struct zero_desc; 25 struct desc_struct ret = zero_desc; 26 27 #ifdef CONFIG_MODIFY_LDT_SYSCALL 28 seg >>= 3; 29 mutex_lock(¤t->mm->context.lock); 30 if (current->mm->context.ldt && seg < current->mm->context.ldt->nr_entries) 31 ret = current->mm->context.ldt->entries[seg]; 32 mutex_unlock(¤t->mm->context.lock); 33 #endif 34 return ret; 35 } 36 37 #define SEG_TYPE_WRITABLE (1U << 1) 38 #define SEG_TYPE_EXPANDS_DOWN (1U << 2) 39 #define SEG_TYPE_EXECUTE (1U << 3) 40 #define SEG_TYPE_EXPAND_MASK (SEG_TYPE_EXPANDS_DOWN | SEG_TYPE_EXECUTE) 41 #define SEG_TYPE_EXECUTE_MASK (SEG_TYPE_WRITABLE | SEG_TYPE_EXECUTE) 42 43 static inline unsigned long seg_get_base(struct desc_struct *d) 44 { 45 unsigned long base = (unsigned long)d->base2 << 24; 46 47 return base | ((unsigned long)d->base1 << 16) | d->base0; 48 } 49 50 static inline unsigned long seg_get_limit(struct desc_struct *d) 51 { 52 return ((unsigned long)d->limit1 << 16) | d->limit0; 53 } 54 55 static inline unsigned long seg_get_granularity(struct desc_struct *d) 56 { 57 return d->g ? 4096 : 1; 58 } 59 60 static inline bool seg_expands_down(struct desc_struct *d) 61 { 62 return (d->type & SEG_TYPE_EXPAND_MASK) == SEG_TYPE_EXPANDS_DOWN; 63 } 64 65 static inline bool seg_execute_only(struct desc_struct *d) 66 { 67 return (d->type & SEG_TYPE_EXECUTE_MASK) == SEG_TYPE_EXECUTE; 68 } 69 70 static inline bool seg_writable(struct desc_struct *d) 71 { 72 return (d->type & SEG_TYPE_EXECUTE_MASK) == SEG_TYPE_WRITABLE; 73 } 74 75 #define I387 (¤t->thread.fpu.state) 76 #define FPU_info (I387->soft.info) 77 78 #define FPU_CS (*(unsigned short *) &(FPU_info->regs->cs)) 79 #define FPU_SS (*(unsigned short *) &(FPU_info->regs->ss)) 80 #define FPU_DS (*(unsigned short *) &(FPU_info->regs->ds)) 81 #define FPU_EAX (FPU_info->regs->ax) 82 #define FPU_EFLAGS (FPU_info->regs->flags) 83 #define FPU_EIP (FPU_info->regs->ip) 84 #define FPU_ORIG_EIP (FPU_info->___orig_eip) 85 86 #define FPU_lookahead (I387->soft.lookahead) 87 88 /* nz if ip_offset and cs_selector are not to be set for the current 89 instruction. */ 90 #define no_ip_update (*(u_char *)&(I387->soft.no_update)) 91 #define FPU_rm (*(u_char *)&(I387->soft.rm)) 92 93 /* Number of bytes of data which can be legally accessed by the current 94 instruction. This only needs to hold a number <= 108, so a byte will do. */ 95 #define access_limit (*(u_char *)&(I387->soft.alimit)) 96 97 #define partial_status (I387->soft.swd) 98 #define control_word (I387->soft.cwd) 99 #define fpu_tag_word (I387->soft.twd) 100 #define registers (I387->soft.st_space) 101 #define top (I387->soft.ftop) 102 103 #define instruction_address (*(struct address *)&I387->soft.fip) 104 #define operand_address (*(struct address *)&I387->soft.foo) 105 106 #define FPU_access_ok(x,y,z) if ( !access_ok(x,y,z) ) \ 107 math_abort(FPU_info,SIGSEGV) 108 #define FPU_abort math_abort(FPU_info, SIGSEGV) 109 110 #undef FPU_IGNORE_CODE_SEGV 111 #ifdef FPU_IGNORE_CODE_SEGV 112 /* access_ok() is very expensive, and causes the emulator to run 113 about 20% slower if applied to the code. Anyway, errors due to bad 114 code addresses should be much rarer than errors due to bad data 115 addresses. */ 116 #define FPU_code_access_ok(z) 117 #else 118 /* A simpler test than access_ok() can probably be done for 119 FPU_code_access_ok() because the only possible error is to step 120 past the upper boundary of a legal code area. */ 121 #define FPU_code_access_ok(z) FPU_access_ok(VERIFY_READ,(void __user *)FPU_EIP,z) 122 #endif 123 124 #define FPU_get_user(x,y) get_user((x),(y)) 125 #define FPU_put_user(x,y) put_user((x),(y)) 126 127 #endif 128