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