src/arch/i386/include/librm.h

   1 #ifndef LIBRM_H
   2 #define LIBRM_H
   3
   4 FILE_LICENCE ( GPL2_OR_LATER );
   5
   6 /* Segment selectors as used in our protected-mode GDTs.
   7  *
   8  * Don't change these unless you really know what you're doing.
   9  */
  10
  11 #define VIRTUAL_CS 0x08
  12 #define VIRTUAL_DS 0x10
  13 #define PHYSICAL_CS 0x18
  14 #define PHYSICAL_DS 0x20
  15 #define REAL_CS 0x28
  16 #define REAL_DS 0x30
  17 #if 0
  18 #define LONG_CS 0x38
  19 #define LONG_DS 0x40
  20 #endif
  21
  22 #ifndef ASSEMBLY
  23
  24 #ifdef UACCESS_LIBRM
  25 #define UACCESS_PREFIX_librm
  26 #else
  27 #define UACCESS_PREFIX_librm __librm_
  28 #endif
  29
  30 /* Variables in librm.S */
  31 extern unsigned long virt_offset;
  32
  33 /**
  34  * Convert physical address to user pointer
  35  *
  36  * @v phys_addr         Physical address
  37  * @ret userptr         User pointer
  38  */
  39 static inline __always_inline userptr_t
  40 UACCESS_INLINE ( librm, phys_to_user ) ( unsigned long phys_addr ) {
  41         return ( phys_addr - virt_offset );
  42 }
  43
  44 /**
  45  * Convert user buffer to physical address
  46  *
  47  * @v userptr           User pointer
  48  * @v offset            Offset from user pointer
  49  * @ret phys_addr       Physical address
  50  */
  51 static inline __always_inline unsigned long
  52 UACCESS_INLINE ( librm, user_to_phys ) ( userptr_t userptr, off_t offset ) {
  53         return ( userptr + offset + virt_offset );
  54 }
  55
  56 static inline __always_inline userptr_t
  57 UACCESS_INLINE ( librm, virt_to_user ) ( volatile const void *addr ) {
  58         return trivial_virt_to_user ( addr );
  59 }
  60
  61 static inline __always_inline void *
  62 UACCESS_INLINE ( librm, user_to_virt ) ( userptr_t userptr, off_t offset ) {
  63         return trivial_user_to_virt ( userptr, offset );
  64 }
  65
  66 static inline __always_inline userptr_t
  67 UACCESS_INLINE ( librm, userptr_add ) ( userptr_t userptr, off_t offset ) {
  68         return trivial_userptr_add ( userptr, offset );
  69 }
  70
  71 static inline __always_inline void
  72 UACCESS_INLINE ( librm, memcpy_user ) ( userptr_t dest, off_t dest_off,
  73                                         userptr_t src, off_t src_off,
  74                                         size_t len ) {
  75         trivial_memcpy_user ( dest, dest_off, src, src_off, len );
  76 }
  77
  78 static inline __always_inline void
  79 UACCESS_INLINE ( librm, memmove_user ) ( userptr_t dest, off_t dest_off,
  80                                          userptr_t src, off_t src_off,
  81                                          size_t len ) {
  82         trivial_memmove_user ( dest, dest_off, src, src_off, len );
  83 }
  84
  85 static inline __always_inline void
  86 UACCESS_INLINE ( librm, memset_user ) ( userptr_t buffer, off_t offset,
  87                                         int c, size_t len ) {
  88         trivial_memset_user ( buffer, offset, c, len );
  89 }
  90
  91 static inline __always_inline size_t
  92 UACCESS_INLINE ( librm, strlen_user ) ( userptr_t buffer, off_t offset ) {
  93         return trivial_strlen_user ( buffer, offset );
  94 }
  95
  96 static inline __always_inline off_t
  97 UACCESS_INLINE ( librm, memchr_user ) ( userptr_t buffer, off_t offset,
  98                                         int c, size_t len ) {
  99         return trivial_memchr_user ( buffer, offset, c, len );
 100 }
 101
 102
 103 /******************************************************************************
 104  *
 105  * Access to variables in .data16 and .text16
 106  *
 107  */
 108
 109 extern char *data16;
 110 extern char *text16;
 111
 112 #define __data16( variable )                                            \
 113         __attribute__ (( section ( ".data16" ) ))                       \
 114         _data16_ ## variable __asm__ ( #variable )
 115
 116 #define __data16_array( variable, array )                               \
 117         __attribute__ (( section ( ".data16" ) ))                       \
 118         _data16_ ## variable array __asm__ ( #variable )
 119
 120 #define __bss16( variable )                                             \
 121         __attribute__ (( section ( ".bss16" ) ))                        \
 122         _data16_ ## variable __asm__ ( #variable )
 123
 124 #define __bss16_array( variable, array )                                \
 125         __attribute__ (( section ( ".bss16" ) ))                        \
 126         _data16_ ## variable array __asm__ ( #variable )
 127
 128 #define __text16( variable )                                            \
 129         __attribute__ (( section ( ".text16.data" ) ))                  \
 130         _text16_ ## variable __asm__ ( #variable )
 131
 132 #define __text16_array( variable, array )                               \
 133         __attribute__ (( section ( ".text16.data" ) ))                  \
 134         _text16_ ## variable array __asm__ ( #variable )
 135
 136 #define __use_data16( variable )                                        \
 137         ( * ( ( typeof ( _data16_ ## variable ) * )                     \
 138               & ( data16 [ ( size_t ) & ( _data16_ ## variable ) ] ) ) )
 139
 140 #define __use_text16( variable )                                        \
 141         ( * ( ( typeof ( _text16_ ## variable ) * )                     \
 142               & ( text16 [ ( size_t ) & ( _text16_ ## variable ) ] ) ) )
 143
 144 #define __from_data16( pointer )                                        \
 145         ( ( unsigned int )                                              \
 146           ( ( ( void * ) (pointer) ) - ( ( void * ) data16 ) ) )
 147
 148 #define __from_text16( pointer )                                        \
 149         ( ( unsigned int )                                              \
 150           ( ( ( void * ) (pointer) ) - ( ( void * ) text16 ) ) )
 151
 152 /* Variables in librm.S, present in the normal data segment */
 153 extern uint16_t rm_sp;
 154 extern uint16_t rm_ss;
 155 extern uint16_t __data16 ( rm_cs );
 156 #define rm_cs __use_data16 ( rm_cs )
 157 extern uint16_t __text16 ( rm_ds );
 158 #define rm_ds __use_text16 ( rm_ds )
 159
 160 /**
 161  * Convert segment:offset address to user buffer
 162  *
 163  * @v segment           Real-mode segment
 164  * @v offset            Real-mode offset
 165  * @ret buffer          User buffer
 166  */
 167 static inline __always_inline userptr_t
 168 real_to_user ( unsigned int segment, unsigned int offset ) {
 169         return ( phys_to_user ( ( segment << 4 ) + offset ) );
 170 }
 171
 172 extern uint16_t copy_user_to_rm_stack ( userptr_t data, size_t size );
 173 extern void remove_user_from_rm_stack ( userptr_t data, size_t size );
 174
 175 /* TEXT16_CODE: declare a fragment of code that resides in .text16 */
 176 #define TEXT16_CODE( asm_code_str )                     \
 177         ".section \".text16\", \"ax\", @progbits\n\t"   \
 178         ".code16\n\t"                                   \
 179         asm_code_str "\n\t"                             \
 180         ".code32\n\t"                                   \
 181         ".previous\n\t"
 182
 183 /* REAL_CODE: declare a fragment of code that executes in real mode */
 184 #define REAL_CODE( asm_code_str )                       \
 185         "pushl $1f\n\t"                                 \
 186         "call real_call\n\t"                            \
 187         "addl $4, %%esp\n\t"                            \
 188         TEXT16_CODE ( "\n1:\n\t"                        \
 189                       asm_code_str                      \
 190                       "\n\t"                            \
 191                       "ret\n\t" )
 192
 193 /* PHYS_CODE: declare a fragment of code that executes in flat physical mode */
 194 #define PHYS_CODE( asm_code_str )                       \
 195         "call _virt_to_phys\n\t"                        \
 196         asm_code_str                                    \
 197         "call _phys_to_virt\n\t"
 198
 199 #endif /* ASSEMBLY */
 200
 201 #endif /* LIBRM_H */