// Code to access multiple segments within gcc. // // Copyright (C) 2008,2009 Kevin O'Connor // // 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