Kernel/arch/arm7/mm_virt.c

   1 /*
   2  * Acess2
   3  *
   4  * ARM7 Virtual Memory Manager
   5  * - arch/arm7/mm_virt.c
   6  */
   7 #include <acess.h>
   8 #include <mm_virt.h>
   9
  10 #define AP_KRW_ONLY     0x1
  11 #define AP_KRO_ONLY     0x5
  12 #define AP_RW_BOTH      0x3
  13 #define AP_RO_BOTH      0x6
  14
  15 // === TYPES ===
  16 typedef struct
  17 {
  18         tPAddr  PhysAddr;
  19         Uint8   Size;
  20         Uint8   Domain;
  21         BOOL    bExecutable;
  22         BOOL    bGlobal;
  23         BOOL    bShared;
  24          int    AP;
  25 } tMM_PageInfo;
  26
  27 // === PROTOTYPES ===
  28  int    MM_int_SetPageInfo(tVAddr VAddr, tMM_PageInfo *pi);
  29  int    MM_int_GetPageInfo(tVAddr VAddr, tMM_PageInfo *pi);
  30
  31 // === GLOBALS ===
  32
  33 // === CODE ===
  34 int MM_InitialiseVirtual(void)
  35 {
  36         return 0;
  37 }
  38
  39 int MM_int_SetPageInfo(tVAddr VAddr, tMM_PageInfo *pi)
  40 {
  41         Uint32  *table0, *table1;
  42         Uint32  *desc;
  43
  44         if(VAddr & 0x80000000 ) {
  45                 table0 = (void*)MM_TABLE0KERN;  // Level 0
  46                 table1 = (void*)MM_TABLE1KERN;  // Level 1
  47         }
  48         else {
  49                 table0 = (void*)MM_TABLE0USER;
  50                 table1 = (void*)MM_TABLE1USER;
  51         }
  52         VAddr &= 0x7FFFFFFF;
  53
  54         desc = &table0[ VAddr >> 20 ];
  55
  56         switch(pi->Size)
  57         {
  58         case 12:        // Small Page
  59         case 16:        // Large Page
  60                 if( (*desc & 3) == 0 ) {
  61                         if( pi->PhysAddr == 0 ) return 0;
  62                         // Allocate
  63                         *desc = MM_AllocPhys();
  64                         *desc |= pi->Domain << 5;
  65                         *desc |= 1;
  66                 }
  67                 desc = &table1[ VAddr >> 12 ];
  68                 if( pi->Size == 12 )
  69                 {
  70                         // Small page
  71                         // - Error if overwriting a large page
  72                         if( (*desc & 3) == 1 )  return 1;
  73                         if( pi->PhysAddr == 0 ) {
  74                                 *desc = 0;
  75                                 return 0;
  76                         }
  77
  78                         *desc = (pi->PhysAddr & 0xFFFFF000) | 2;
  79                         if(!pi->bExecutable)    *desc |= 1;     // XN
  80                         if(!pi->bGlobal)        *desc |= 1 << 11;       // NG
  81                         if( pi->bShared)        *desc |= 1 << 10;       // S
  82                         *desc |= (pi->AP & 3) << 4;     // AP
  83                         *desc |= ((pi->AP >> 2) & 1) << 9;      // APX
  84                 }
  85                 else
  86                 {
  87                         // Large page
  88                         // TODO:
  89                 }
  90                 break;
  91         case 20:        // Section or unmapped
  92                 Log_Warning("MM", "TODO: Implement sections");
  93                 break;
  94         case 24:        // Supersection
  95                 // Error if not aligned
  96                 if( VAddr & 0xFFFFFF ) {
  97                         return 1;
  98                 }
  99                 if( (*desc & 3) == 0 || ((*desc & 3) == 2 && (*desc & (1 << 18)))  )
 100                 {
 101                         if( pi->PhysAddr == 0 ) {
 102                                 *desc = 0;
 103                                 // TODO: Apply to all entries
 104                                 return 0;
 105                         }
 106                         // Apply
 107                         *desc = pi->PhysAddr & 0xFF000000;
 108 //                      *desc |= ((pi->PhysAddr >> 32) & 0xF) << 20;
 109 //                      *desc |= ((pi->PhysAddr >> 36) & 0x7) << 5;
 110                         *desc |= 2 | (1 << 18);
 111                         // TODO: Apply to all entries
 112                         return 0;
 113                 }
 114                 return 1;
 115         }
 116
 117         return 1;
 118 }
 119
 120 int MM_int_GetPageInfo(tVAddr VAddr, tMM_PageInfo *pi)
 121 {
 122         Uint32  *table0, *table1;
 123         Uint32  desc;
 124
 125         if(VAddr & 0x80000000 ) {
 126                 table0 = (void*)MM_TABLE0KERN;  // Level 0
 127                 table1 = (void*)MM_TABLE1KERN;  // Level 1
 128         }
 129         else {
 130                 table0 = (void*)MM_TABLE0USER;
 131                 table1 = (void*)MM_TABLE1USER;
 132         }
 133         VAddr &= 0x7FFFFFFF;
 134
 135         desc = table0[ VAddr >> 20 ];
 136
 137         pi->bExecutable = 1;
 138         pi->bGlobal = 0;
 139         pi->bShared = 0;
 140
 141         switch( (desc & 3) )
 142         {
 143         // 0: Unmapped
 144         case 0:
 145                 pi->PhysAddr = 0;
 146                 pi->Size = 20;
 147                 pi->Domain = 0;
 148                 return 1;
 149
 150         // 1: Coarse page table
 151         case 1:
 152                 // Domain from top level table
 153                 pi->Domain = (desc >> 5) & 7;
 154                 // Get next level
 155                 desc = table1[ VAddr >> 12 ];
 156                 switch( desc & 3 )
 157                 {
 158                 // 0: Unmapped
 159                 case 0:
 160                         pi->Size = 12;
 161                         return 1;
 162                 // 1: Large Page (64KiB)
 163                 case 1:
 164                         pi->Size = 16;
 165                         pi->PhysAddr = desc & 0xFFFF0000;
 166                         return 0;
 167                 // 2/3: Small page
 168                 case 2:
 169                 case 3:
 170                         pi->Size = 12;
 171                         pi->PhysAddr = desc & 0xFFFFF000;
 172                         pi->bExecutable = desc & 1;
 173                         pi->bGlobal = !(desc >> 11);
 174                         pi->bShared = (desc >> 10) & 1;
 175                         return 1;
 176                 }
 177                 return 1;
 178
 179         // 2: Section (or Supersection)
 180         case 2:
 181                 if( desc & (1 << 18) ) {
 182                         // Supersection
 183                         pi->PhysAddr = desc & 0xFF000000;
 184                         pi->PhysAddr |= (Uint64)((desc >> 20) & 0xF) << 32;
 185                         pi->PhysAddr |= (Uint64)((desc >> 5) & 0x7) << 36;
 186                         pi->Size = 24;
 187                         pi->Domain = 0; // Superpages default to zero
 188                         return 0;
 189                 }
 190
 191                 // Section
 192                 pi->PhysAddr = desc & 0xFFF80000;
 193                 pi->Size = 20;
 194                 pi->Domain = (desc >> 5) & 7;
 195                 return 0;
 196
 197         // 3: Reserved (invalid)
 198         case 3:
 199                 pi->PhysAddr = 0;
 200                 pi->Size = 20;
 201                 pi->Domain = 0;
 202                 return 2;
 203         }
 204         return 2;
 205 }
 206
 207 // --- Exports ---
 208 tPAddr MM_GetPhysAddr(tVAddr VAddr)
 209 {
 210         tMM_PageInfo    pi;
 211         if( MM_int_GetPageInfo(VAddr, &pi) )
 212                 return 0;
 213         return pi.PhysAddr;
 214 }
 215
 216 Uint MM_GetFlags(tVAddr VAddr)
 217 {
 218         tMM_PageInfo    pi;
 219          int    ret;
 220
 221         if( MM_int_GetPageInfo(VAddr, &pi) )
 222                 return 0;
 223
 224         ret = 0;
 225
 226         switch(pi.AP)
 227         {
 228         case AP_KRW_ONLY:
 229                 ret |= MM_PFLAG_KERNEL;
 230                 break;
 231         case AP_KRO_ONLY:
 232                 ret |= MM_PFLAG_KERNEL|MM_PFLAG_RO;
 233                 break;
 234         case AP_RW_BOTH:
 235                 break;
 236         case AP_RO_BOTH:
 237                 ret |= MM_PFLAG_RO;
 238                 break;
 239         }
 240
 241         if( pi.bExecutable )    ret |= MM_PFLAG_EXEC;
 242         return ret;
 243 }
 244
 245 void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
 246 {
 247         tMM_PageInfo    pi;
 248         if( MM_int_GetPageInfo(VAddr, &pi) )
 249                 return;
 250
 251
 252
 253 }
 254
 255 int MM_Map(tVAddr VAddr, tPAddr PAddr)
 256 {
 257         tMM_PageInfo    pi = {0};
 258         pi.PhysAddr = PAddr;
 259         pi.Size = 12;
 260         pi.AP = AP_KRW_ONLY;    // Kernel Read/Write
 261         pi.bExecutable = 1;
 262         if( MM_int_SetPageInfo(VAddr, &pi) ) {
 263                 MM_DerefPhys(pi.PhysAddr);
 264                 return 0;
 265         }
 266         return pi.PhysAddr;
 267 }
 268
 269 tPAddr MM_Allocate(tVAddr VAddr)
 270 {
 271         tMM_PageInfo    pi = {0};
 272
 273         pi.PhysAddr = MM_AllocPhys();
 274         if( pi.PhysAddr == 0 )  return 0;
 275         pi.Size = 12;
 276         pi.AP = AP_KRW_ONLY;    // Kernel Read/Write
 277         pi.bExecutable = 1;
 278         if( MM_int_SetPageInfo(VAddr, &pi) ) {
 279                 MM_DerefPhys(pi.PhysAddr);
 280                 return 0;
 281         }
 282         return pi.PhysAddr;
 283 }
 284
 285 void MM_Deallocate(tVAddr VAddr)
 286 {
 287         tMM_PageInfo    pi;
 288
 289         if( MM_int_GetPageInfo(VAddr, &pi) )    return ;
 290
 291         if( pi.PhysAddr == 0 )  return;
 292         MM_DerefPhys(pi.PhysAddr);
 293
 294         pi.PhysAddr = 0;
 295         pi.AP = 0;
 296         pi.bExecutable = 0;
 297         MM_int_SetPageInfo(VAddr, &pi);
 298 }