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/* This sets the pointer FPU_info to point to the argument part 20 of the stack frame of math_emulate() */ 21#define SETUP_DATA_AREA(arg) FPU_info = (struct info *) &arg 22 23/* s is always from a cpu register, and the cpu does bounds checking 24 * during register load --> no further bounds checks needed */ 25#define LDT_DESCRIPTOR(s) (((struct desc_struct *)current->mm->context.ldt)[(s) >> 3]) 26#define SEG_D_SIZE(x) ((x).b & (3 << 21)) 27#define SEG_G_BIT(x) ((x).b & (1 << 23)) 28#define SEG_GRANULARITY(x) (((x).b & (1 << 23)) ? 4096 : 1) 29#define SEG_286_MODE(x) ((x).b & ( 0xff000000 | 0xf0000 | (1 << 23))) 30#define SEG_BASE_ADDR(s) (((s).b & 0xff000000) \ 31 | (((s).b & 0xff) << 16) | ((s).a >> 16)) 32#define SEG_LIMIT(s) (((s).b & 0xff0000) | ((s).a & 0xffff)) 33#define SEG_EXECUTE_ONLY(s) (((s).b & ((1 << 11) | (1 << 9))) == (1 << 11)) 34#define SEG_WRITE_PERM(s) (((s).b & ((1 << 11) | (1 << 9))) == (1 << 9)) 35#define SEG_EXPAND_DOWN(s) (((s).b & ((1 << 11) | (1 << 10))) \ 36 == (1 << 10)) 37 38#define I387 (current->thread.i387) 39#define FPU_info (I387.soft.info) 40 41#define FPU_CS (*(unsigned short *) &(FPU_info->___cs)) 42#define FPU_SS (*(unsigned short *) &(FPU_info->___ss)) 43#define FPU_DS (*(unsigned short *) &(FPU_info->___ds)) 44#define FPU_EAX (FPU_info->___eax) 45#define FPU_EFLAGS (FPU_info->___eflags) 46#define FPU_EIP (FPU_info->___eip) 47#define FPU_ORIG_EIP (FPU_info->___orig_eip) 48 49#define FPU_lookahead (I387.soft.lookahead) 50 51/* nz if ip_offset and cs_selector are not to be set for the current 52 instruction. */ 53#define no_ip_update (*(u_char *)&(I387.soft.no_update)) 54#define FPU_rm (*(u_char *)&(I387.soft.rm)) 55 56/* Number of bytes of data which can be legally accessed by the current 57 instruction. This only needs to hold a number <= 108, so a byte will do. */ 58#define access_limit (*(u_char *)&(I387.soft.alimit)) 59 60#define partial_status (I387.soft.swd) 61#define control_word (I387.soft.cwd) 62#define fpu_tag_word (I387.soft.twd) 63#define registers (I387.soft.st_space) 64#define top (I387.soft.ftop) 65 66#define instruction_address (*(struct address *)&I387.soft.fip) 67#define operand_address (*(struct address *)&I387.soft.foo) 68 69#define FPU_access_ok(x,y,z) if ( !access_ok(x,y,z) ) \ 70 math_abort(FPU_info,SIGSEGV) 71#define FPU_abort math_abort(FPU_info, SIGSEGV) 72 73#undef FPU_IGNORE_CODE_SEGV 74#ifdef FPU_IGNORE_CODE_SEGV 75/* access_ok() is very expensive, and causes the emulator to run 76 about 20% slower if applied to the code. Anyway, errors due to bad 77 code addresses should be much rarer than errors due to bad data 78 addresses. */ 79#define FPU_code_access_ok(z) 80#else 81/* A simpler test than access_ok() can probably be done for 82 FPU_code_access_ok() because the only possible error is to step 83 past the upper boundary of a legal code area. */ 84#define FPU_code_access_ok(z) FPU_access_ok(VERIFY_READ,(void __user *)FPU_EIP,z) 85#endif 86 87#define FPU_get_user(x,y) get_user((x),(y)) 88#define FPU_put_user(x,y) put_user((x),(y)) 89 90#endif 91