1 /*---------------------------------------------------------------------------+
4 | Copyright (C) 1992,1994,1997 |
5 | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
6 | Australia. E-mail billm@suburbia.net |
8 +---------------------------------------------------------------------------*/
13 /* system dependent definitions */
15 #include <linux/sched.h>
16 #include <linux/kernel.h>
18 #include <asm/atomic_kmap.h>
20 /* This sets the pointer FPU_info to point to the argument part
21 of the stack frame of math_emulate() */
22 #define SETUP_DATA_AREA(arg) FPU_info = (struct info *) &arg
24 /* s is always from a cpu register, and the cpu does bounds checking
25 * during register load --> no further bounds checks needed */
26 #define LDT_DESCRIPTOR(s) (((struct desc_struct *)__kmap_atomic_vaddr(KM_LDT_PAGE0))[(s) >> 3])
27 #define SEG_D_SIZE(x) ((x).b & (3 << 21))
28 #define SEG_G_BIT(x) ((x).b & (1 << 23))
29 #define SEG_GRANULARITY(x) (((x).b & (1 << 23)) ? 4096 : 1)
30 #define SEG_286_MODE(x) ((x).b & ( 0xff000000 | 0xf0000 | (1 << 23)))
31 #define SEG_BASE_ADDR(s) (((s).b & 0xff000000) \
32 | (((s).b & 0xff) << 16) | ((s).a >> 16))
33 #define SEG_LIMIT(s) (((s).b & 0xff0000) | ((s).a & 0xffff))
34 #define SEG_EXECUTE_ONLY(s) (((s).b & ((1 << 11) | (1 << 9))) == (1 << 11))
35 #define SEG_WRITE_PERM(s) (((s).b & ((1 << 11) | (1 << 9))) == (1 << 9))
36 #define SEG_EXPAND_DOWN(s) (((s).b & ((1 << 11) | (1 << 10))) \
39 #define I387 (current->thread.i387)
40 #define FPU_info (I387.soft.info)
42 #define FPU_CS (*(unsigned short *) &(FPU_info->___cs))
43 #define FPU_SS (*(unsigned short *) &(FPU_info->___ss))
44 #define FPU_DS (*(unsigned short *) &(FPU_info->___ds))
45 #define FPU_EAX (FPU_info->___eax)
46 #define FPU_EFLAGS (FPU_info->___eflags)
47 #define FPU_EIP (FPU_info->___eip)
48 #define FPU_ORIG_EIP (FPU_info->___orig_eip)
50 #define FPU_lookahead (I387.soft.lookahead)
52 /* nz if ip_offset and cs_selector are not to be set for the current
54 #define no_ip_update (*(u_char *)&(I387.soft.no_update))
55 #define FPU_rm (*(u_char *)&(I387.soft.rm))
57 /* Number of bytes of data which can be legally accessed by the current
58 instruction. This only needs to hold a number <= 108, so a byte will do. */
59 #define access_limit (*(u_char *)&(I387.soft.alimit))
61 #define partial_status (I387.soft.swd)
62 #define control_word (I387.soft.cwd)
63 #define fpu_tag_word (I387.soft.twd)
64 #define registers (I387.soft.st_space)
65 #define top (I387.soft.ftop)
67 #define instruction_address (*(struct address *)&I387.soft.fip)
68 #define operand_address (*(struct address *)&I387.soft.foo)
70 #define FPU_verify_area(x,y,z) if ( verify_area(x,y,z) ) \
71 math_abort(FPU_info,SIGSEGV)
73 #undef FPU_IGNORE_CODE_SEGV
74 #ifdef FPU_IGNORE_CODE_SEGV
75 /* verify_area() 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
79 #define FPU_code_verify_area(z)
81 /* A simpler test than verify_area() can probably be done for
82 FPU_code_verify_area() because the only possible error is to step
83 past the upper boundary of a legal code area. */
84 #define FPU_code_verify_area(z) FPU_verify_area(VERIFY_READ,(void *)FPU_EIP,z)
87 #define FPU_get_user(x,y) get_user((x),(y))
88 #define FPU_put_user(x,y) put_user((x),(y))