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->size) 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_D_SIZE(x) ((x).b & (3 << 21)) 38 #define SEG_G_BIT(x) ((x).b & (1 << 23)) 39 #define SEG_GRANULARITY(x) (((x).b & (1 << 23)) ? 4096 : 1) 40 #define SEG_286_MODE(x) ((x).b & ( 0xff000000 | 0xf0000 | (1 << 23))) 41 #define SEG_BASE_ADDR(s) (((s).b & 0xff000000) \ 42 | (((s).b & 0xff) << 16) | ((s).a >> 16)) 43 #define SEG_LIMIT(s) (((s).b & 0xff0000) | ((s).a & 0xffff)) 44 #define SEG_EXECUTE_ONLY(s) (((s).b & ((1 << 11) | (1 << 9))) == (1 << 11)) 45 #define SEG_WRITE_PERM(s) (((s).b & ((1 << 11) | (1 << 9))) == (1 << 9)) 46 #define SEG_EXPAND_DOWN(s) (((s).b & ((1 << 11) | (1 << 10))) \ 47 == (1 << 10)) 48 49 #define I387 (¤t->thread.fpu.state) 50 #define FPU_info (I387->soft.info) 51 52 #define FPU_CS (*(unsigned short *) &(FPU_info->regs->cs)) 53 #define FPU_SS (*(unsigned short *) &(FPU_info->regs->ss)) 54 #define FPU_DS (*(unsigned short *) &(FPU_info->regs->ds)) 55 #define FPU_EAX (FPU_info->regs->ax) 56 #define FPU_EFLAGS (FPU_info->regs->flags) 57 #define FPU_EIP (FPU_info->regs->ip) 58 #define FPU_ORIG_EIP (FPU_info->___orig_eip) 59 60 #define FPU_lookahead (I387->soft.lookahead) 61 62 /* nz if ip_offset and cs_selector are not to be set for the current 63 instruction. */ 64 #define no_ip_update (*(u_char *)&(I387->soft.no_update)) 65 #define FPU_rm (*(u_char *)&(I387->soft.rm)) 66 67 /* Number of bytes of data which can be legally accessed by the current 68 instruction. This only needs to hold a number <= 108, so a byte will do. */ 69 #define access_limit (*(u_char *)&(I387->soft.alimit)) 70 71 #define partial_status (I387->soft.swd) 72 #define control_word (I387->soft.cwd) 73 #define fpu_tag_word (I387->soft.twd) 74 #define registers (I387->soft.st_space) 75 #define top (I387->soft.ftop) 76 77 #define instruction_address (*(struct address *)&I387->soft.fip) 78 #define operand_address (*(struct address *)&I387->soft.foo) 79 80 #define FPU_access_ok(x,y,z) if ( !access_ok(x,y,z) ) \ 81 math_abort(FPU_info,SIGSEGV) 82 #define FPU_abort math_abort(FPU_info, SIGSEGV) 83 84 #undef FPU_IGNORE_CODE_SEGV 85 #ifdef FPU_IGNORE_CODE_SEGV 86 /* access_ok() is very expensive, and causes the emulator to run 87 about 20% slower if applied to the code. Anyway, errors due to bad 88 code addresses should be much rarer than errors due to bad data 89 addresses. */ 90 #define FPU_code_access_ok(z) 91 #else 92 /* A simpler test than access_ok() can probably be done for 93 FPU_code_access_ok() because the only possible error is to step 94 past the upper boundary of a legal code area. */ 95 #define FPU_code_access_ok(z) FPU_access_ok(VERIFY_READ,(void __user *)FPU_EIP,z) 96 #endif 97 98 #define FPU_get_user(x,y) get_user((x),(y)) 99 #define FPU_put_user(x,y) put_user((x),(y)) 100 101 #endif 102