| // Code to access multiple segments within gcc. |
| // |
| // Copyright (C) 2008,2009 Kevin O'Connor <kevin@koconnor.net> |
| // |
| // This file may be distributed under the terms of the GNU LGPLv3 license. |
| #ifndef __FARPTR_H |
| #define __FARPTR_H |
| |
| #include "x86.h" // insb |
| |
| // Dummy definitions used to make sure gcc understands dependencies |
| // between SET_SEG and GET/READ/WRITE_SEG macros. |
| extern u16 __segment_ES, __segment_CS, __segment_DS, __segment_SS; |
| extern u16 __segment_FS, __segment_GS; |
| |
| // Low level macros for reading/writing memory via a segment selector. |
| #define READ8_SEG(prefix, SEG, value, var) \ |
| __asm__(prefix "movb %%" #SEG ":%1, %b0" : "=Qi"(value) \ |
| : "m"(var), "m"(__segment_ ## SEG)) |
| #define READ16_SEG(prefix, SEG, value, var) \ |
| __asm__(prefix "movw %%" #SEG ":%1, %w0" : "=ri"(value) \ |
| : "m"(var), "m"(__segment_ ## SEG)) |
| #define READ32_SEG(prefix, SEG, value, var) \ |
| __asm__(prefix "movl %%" #SEG ":%1, %0" : "=ri"(value) \ |
| : "m"(var), "m"(__segment_ ## SEG)) |
| #define READ64_SEG(prefix, SEG, value, var) do { \ |
| union u64_u32_u __value; \ |
| union u64_u32_u *__r64_ptr = (union u64_u32_u *)&(var); \ |
| READ32_SEG(prefix, SEG, __value.lo, __r64_ptr->lo); \ |
| READ32_SEG(prefix, SEG, __value.hi, __r64_ptr->hi); \ |
| *(u64*)&(value) = __value.val; \ |
| } while (0) |
| #define WRITE8_SEG(prefix, SEG, var, value) \ |
| __asm__(prefix "movb %b1, %%" #SEG ":%0" : "=m"(var) \ |
| : "Q"(value), "m"(__segment_ ## SEG)) |
| #define WRITE16_SEG(prefix, SEG, var, value) \ |
| __asm__(prefix "movw %w1, %%" #SEG ":%0" : "=m"(var) \ |
| : "r"(value), "m"(__segment_ ## SEG)) |
| #define WRITE32_SEG(prefix, SEG, var, value) \ |
| __asm__(prefix "movl %1, %%" #SEG ":%0" : "=m"(var) \ |
| : "r"(value), "m"(__segment_ ## SEG)) |
| #define WRITE64_SEG(prefix, SEG, var, value) do { \ |
| union u64_u32_u __value; \ |
| union u64_u32_u *__w64_ptr = (union u64_u32_u *)&(var); \ |
| typeof(var) __value_tmp = (value); \ |
| __value.val = *(u64*)&__value_tmp; \ |
| WRITE32_SEG(prefix, SEG, __w64_ptr->lo, __value.lo); \ |
| WRITE32_SEG(prefix, SEG, __w64_ptr->hi, __value.hi); \ |
| } while (0) |
| |
| // Macros for automatically choosing the appropriate memory size |
| // access method. |
| extern void __force_link_error__unknown_type(void); |
| |
| #define __GET_VAR(prefix, seg, var) ({ \ |
| typeof(var) __val; \ |
| if (sizeof(__val) == 1) \ |
| READ8_SEG(prefix, seg, __val, var); \ |
| else if (sizeof(__val) == 2) \ |
| READ16_SEG(prefix, seg, __val, var); \ |
| else if (sizeof(__val) == 4) \ |
| READ32_SEG(prefix, seg, __val, var); \ |
| else if (sizeof(__val) == 8) \ |
| READ64_SEG(prefix, seg, __val, var); \ |
| else \ |
| __force_link_error__unknown_type(); \ |
| __val; }) |
| |
| #define __SET_VAR(prefix, seg, var, val) do { \ |
| if (sizeof(var) == 1) \ |
| WRITE8_SEG(prefix, seg, var, (val)); \ |
| else if (sizeof(var) == 2) \ |
| WRITE16_SEG(prefix, seg, var, (val)); \ |
| else if (sizeof(var) == 4) \ |
| WRITE32_SEG(prefix, seg, var, (val)); \ |
| else if (sizeof(var) == 8) \ |
| WRITE64_SEG(prefix, seg, var, (val)); \ |
| else \ |
| __force_link_error__unknown_type(); \ |
| } while (0) |
| |
| #define DECL_SEGFUNCS(SEG) \ |
| static inline void __set_seg_##SEG(u16 seg) { \ |
| __asm__("movw %w1, %%" #SEG : "=m"(__segment_##SEG) \ |
| : "rm"(seg)); \ |
| } \ |
| static inline u16 __get_seg_##SEG(void) { \ |
| u16 res; \ |
| __asm__("movw %%" #SEG ", %w0" : "=rm"(res) \ |
| : "m"(__segment_##SEG)); \ |
| return res; \ |
| } |
| DECL_SEGFUNCS(CS) |
| DECL_SEGFUNCS(DS) |
| DECL_SEGFUNCS(ES) |
| DECL_SEGFUNCS(FS) |
| DECL_SEGFUNCS(GS) |
| DECL_SEGFUNCS(SS) |
| |
| // Low level macros for getting/setting a segment register. |
| #define __SET_SEG(SEG, value) \ |
| __set_seg_##SEG(value) |
| #define __GET_SEG(SEG) \ |
| __get_seg_##SEG() |
| |
| // Macros for accessing a variable in another segment. (They |
| // automatically update the %es segment and then make the appropriate |
| // access.) |
| #define __GET_FARVAR(seg, var) ({ \ |
| SET_SEG(ES, (seg)); \ |
| GET_VAR(ES, (var)); }) |
| #define __SET_FARVAR(seg, var, val) do { \ |
| typeof(var) __sfv_val = (val); \ |
| SET_SEG(ES, (seg)); \ |
| SET_VAR(ES, (var), __sfv_val); \ |
| } while (0) |
| |
| // Macros for accesssing a 32bit flat mode pointer from 16bit real |
| // mode. (They automatically update the %es segment, break the |
| // pointer into segment/offset, and then make the access.) |
| #define __GET_FLATPTR(ptr) ({ \ |
| typeof(&(ptr)) __ptr = &(ptr); \ |
| GET_FARVAR(FLATPTR_TO_SEG(__ptr) \ |
| , *(typeof(__ptr))FLATPTR_TO_OFFSET(__ptr)); }) |
| #define __SET_FLATPTR(ptr, val) do { \ |
| typeof (&(ptr)) __ptr = &(ptr); \ |
| SET_FARVAR(FLATPTR_TO_SEG(__ptr) \ |
| , *(typeof(__ptr))FLATPTR_TO_OFFSET(__ptr) \ |
| , (val)); \ |
| } while (0) |
| |
| // Macros for converting to/from 32bit flat mode pointers to their |
| // equivalent 16bit segment/offset values. |
| #define FLATPTR_TO_SEG(p) (((u32)(p)) >> 4) |
| #define FLATPTR_TO_OFFSET(p) (((u32)(p)) & 0xf) |
| #define MAKE_FLATPTR(seg,off) ((void*)(((u32)(seg)<<4)+(u32)(off))) |
| |
| |
| #if MODESEGMENT == 1 |
| |
| // Definitions when using segmented mode. |
| #define GET_FARVAR(seg, var) __GET_FARVAR((seg), (var)) |
| #define SET_FARVAR(seg, var, val) __SET_FARVAR((seg), (var), (val)) |
| #define GET_VAR(seg, var) __GET_VAR("", seg, (var)) |
| #define SET_VAR(seg, var, val) __SET_VAR("", seg, (var), (val)) |
| #define SET_SEG(SEG, value) __SET_SEG(SEG, (value)) |
| #define GET_SEG(SEG) __GET_SEG(SEG) |
| #define GET_FLATPTR(ptr) __GET_FLATPTR(ptr) |
| #define SET_FLATPTR(ptr, val) __SET_FLATPTR((ptr), (val)) |
| |
| static inline void insb_fl(u16 port, void *ptr_fl, u16 count) { |
| SET_SEG(ES, FLATPTR_TO_SEG(ptr_fl)); |
| insb(port, (u8*)FLATPTR_TO_OFFSET(ptr_fl), count); |
| } |
| static inline void insw_fl(u16 port, void *ptr_fl, u16 count) { |
| SET_SEG(ES, FLATPTR_TO_SEG(ptr_fl)); |
| insw(port, (u16*)FLATPTR_TO_OFFSET(ptr_fl), count); |
| } |
| static inline void insl_fl(u16 port, void *ptr_fl, u16 count) { |
| SET_SEG(ES, FLATPTR_TO_SEG(ptr_fl)); |
| insl(port, (u32*)FLATPTR_TO_OFFSET(ptr_fl), count); |
| } |
| static inline void outsb_fl(u16 port, void *ptr_fl, u16 count) { |
| SET_SEG(ES, FLATPTR_TO_SEG(ptr_fl)); |
| outsb(port, (u8*)FLATPTR_TO_OFFSET(ptr_fl), count); |
| } |
| static inline void outsw_fl(u16 port, void *ptr_fl, u16 count) { |
| SET_SEG(ES, FLATPTR_TO_SEG(ptr_fl)); |
| outsw(port, (u16*)FLATPTR_TO_OFFSET(ptr_fl), count); |
| } |
| static inline void outsl_fl(u16 port, void *ptr_fl, u16 count) { |
| SET_SEG(ES, FLATPTR_TO_SEG(ptr_fl)); |
| outsl(port, (u32*)FLATPTR_TO_OFFSET(ptr_fl), count); |
| } |
| |
| #else |
| |
| // In 32-bit flat mode there is no need to mess with the segments. |
| #define GET_FARVAR(seg, var) \ |
| (*((typeof(&(var)))MAKE_FLATPTR((seg), &(var)))) |
| #define SET_FARVAR(seg, var, val) \ |
| do { GET_FARVAR((seg), (var)) = (val); } while (0) |
| #define GET_VAR(seg, var) (var) |
| #define SET_VAR(seg, var, val) do { (var) = (val); } while (0) |
| #define SET_SEG(SEG, value) ((void)(value)) |
| #define GET_SEG(SEG) 0 |
| #define GET_FLATPTR(ptr) (ptr) |
| #define SET_FLATPTR(ptr, val) do { (ptr) = (val); } while (0) |
| |
| #define insb_fl(port, ptr_fl, count) insb(port, ptr_fl, count) |
| #define insw_fl(port, ptr_fl, count) insw(port, ptr_fl, count) |
| #define insl_fl(port, ptr_fl, count) insl(port, ptr_fl, count) |
| #define outsb_fl(port, ptr_fl, count) outsb(port, ptr_fl, count) |
| #define outsw_fl(port, ptr_fl, count) outsw(port, ptr_fl, count) |
| #define outsl_fl(port, ptr_fl, count) outsl(port, ptr_fl, count) |
| |
| #endif |
| |
| #define SEGOFF(s,o) ({struct segoff_s __so; __so.offset=(o); __so.seg=(s); __so;}) |
| |
| static inline struct segoff_s FLATPTR_TO_SEGOFF(void *p) { |
| return SEGOFF(FLATPTR_TO_SEG(p), FLATPTR_TO_OFFSET(p)); |
| } |
| static inline void *SEGOFF_TO_FLATPTR(struct segoff_s so) { |
| return MAKE_FLATPTR(so.seg, so.offset); |
| } |
| |
| #endif // farptr.h |
