4 * Virtual Memory Manager
16 #define PADDR_MASK 0x7FFFFFFF##FFFFF000
17 #define PAGE_MASK (((Uint)1 << 36)-1)
18 #define TABLE_MASK (((Uint)1 << 27)-1)
19 #define PDP_MASK (((Uint)1 << 18)-1)
20 #define PML4_MASK (((Uint)1 << 9)-1)
22 #define PF_PRESENT 0x1
26 #define PF_PAGED 0x400
27 #define PF_NX 0x80000000##00000000
30 #define PAGETABLE(idx) (*((tPAddr*)MM_FRACTAL_BASE+((idx)&PAGE_MASK)))
31 #define PAGEDIR(idx) PAGETABLE((MM_FRACTAL_BASE>>12)+((idx)&TABLE_MASK))
32 #define PAGEDIRPTR(idx) PAGEDIR((MM_FRACTAL_BASE>>21)+((idx)&PDP_MASK))
33 #define PAGEMAPLVL4(idx) PAGEDIRPTR((MM_FRACTAL_BASE>>30)+((idx)&PML4_MASK))
36 void MM_InitVirt(void);
37 void MM_FinishVirtualInit(void);
38 void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs);
39 void MM_DumpTables(tVAddr Start, tVAddr End);
40 int MM_Map(tVAddr VAddr, tPAddr PAddr);
45 void MM_InitVirt(void)
49 void MM_FinishVirtualInit(void)
54 * \brief Called on a page fault
56 void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
58 // TODO: Copy on Write
60 if( gaPageDir [Addr>>22] & PF_PRESENT
61 && gaPageTable[Addr>>12] & PF_PRESENT
62 && gaPageTable[Addr>>12] & PF_COW )
65 if(MM_GetRefCount( gaPageTable[Addr>>12] & ~0xFFF ) == 1)
67 gaPageTable[Addr>>12] &= ~PF_COW;
68 gaPageTable[Addr>>12] |= PF_PRESENT|PF_WRITE;
72 //Log("MM_PageFault: COW - MM_DuplicatePage(0x%x)", Addr);
73 paddr = MM_DuplicatePage( Addr );
74 MM_DerefPhys( gaPageTable[Addr>>12] & ~0xFFF );
75 gaPageTable[Addr>>12] &= PF_USER;
76 gaPageTable[Addr>>12] |= paddr|PF_PRESENT|PF_WRITE;
79 INVLPG( Addr & ~0xFFF );
84 // If it was a user, tell the thread handler
86 Warning("%s %s %s memory%s",
87 (ErrorCode&4?"User":"Kernel"),
88 (ErrorCode&2?"write to":"read from"),
89 (ErrorCode&1?"bad/locked":"non-present"),
90 (ErrorCode&16?" (Instruction Fetch)":"")
92 Warning("User Pagefault: Instruction at %04x:%08x accessed %p",
93 Regs->CS, Regs->RIP, Addr);
94 __asm__ __volatile__ ("sti"); // Restart IRQs
95 // Threads_SegFault(Addr);
101 // -- Check Error Code --
103 Warning("Reserved Bits Trashed!");
106 Warning("%s %s %s memory%s",
107 (ErrorCode&4?"User":"Kernel"),
108 (ErrorCode&2?"write to":"read from"),
109 (ErrorCode&1?"bad/locked":"non-present"),
110 (ErrorCode&16?" (Instruction Fetch)":"")
114 Log("Code at %p accessed %p", Regs->RIP, Addr);
115 // Print Stack Backtrace
116 // Error_Backtrace(Regs->RIP, Regs->RBP);
118 MM_DumpTables(0, -1);
122 * \brief Dumps the layout of the page tables
124 void MM_DumpTables(tVAddr Start, tVAddr End)
126 tVAddr rangeStart = 0;
130 const tPAddr MASK = ~0xF98; // Physical address and access bits
132 Start >>= 12; End >>= 12;
134 Log("Table Entries:");
135 for(page = Start, curPos = Start<<12;
136 page < (End & (((tVAddr)1 << 48)-1));
137 curPos += 0x1000, page++)
141 !(PAGEMAPLVL4(page>>27) & PF_PRESENT)
142 || !(PAGEDIRPTR(page>>18) & PF_PRESENT)
143 || !(PAGEDIR(page>>9) & PF_PRESENT)
144 || !(PAGETABLE(page) & PF_PRESENT)
145 || (PAGETABLE(page) & MASK) != expected)
148 Log(" 0x%08x-0x%08x => 0x%08x-0x%08x (%s%s%s%s)",
149 rangeStart, curPos - 1,
150 PAGETABLE(rangeStart>>12) & ~0xFFF,
151 (expected & ~0xFFF) - 1,
152 (expected & PF_PAGED ? "p" : "-"),
153 (expected & PF_COW ? "C" : "-"),
154 (expected & PF_USER ? "U" : "-"),
155 (expected & PF_WRITE ? "W" : "-")
159 if( !(PAGEMAPLVL4(page>>27) & PF_PRESENT) ) continue;
160 if( !(PAGEDIRPTR(page>>18) & PF_PRESENT) ) continue;
161 if( !(PAGEDIR(page>>9) & PF_PRESENT) ) continue;
162 if( !(PAGETABLE(page) & PF_PRESENT) ) continue;
164 expected = (PAGETABLE(page) & MASK);
167 if(expected) expected += 0x1000;
171 Log("0x%08x-0x%08x => 0x%08x-0x%08x (%s%s%s%s)",
172 rangeStart, curPos - 1,
173 PAGETABLE(rangeStart>>12) & ~0xFFF,
174 (expected & ~0xFFF) - 1,
175 (expected & PF_PAGED ? "p" : "-"),
176 (expected & PF_COW ? "C" : "-"),
177 (expected & PF_USER ? "U" : "-"),
178 (expected & PF_WRITE ? "W" : "-")
185 * \brief Map a physical page to a virtual one
187 int MM_Map(tVAddr VAddr, tPAddr PAddr)
191 Log("MM_Map: (VAddr=0x%x, PAddr=0x%x)", VAddr, PAddr);
194 //Log(" MM_Map: &PAGEMAPLVL4(%x) = %x", VAddr >> 39, &PAGEMAPLVL4(VAddr >> 39));
195 //Log(" MM_Map: &PAGEDIRPTR(%x) = %x", VAddr >> 30, &PAGEDIRPTR(VAddr >> 30));
196 //Log(" MM_Map: &PAGEDIR(%x) = %x", VAddr >> 21, &PAGEDIR(VAddr >> 21));
197 //Log(" MM_Map: &PAGETABLE(%x) = %x", VAddr >> 12, &PAGETABLE(VAddr >> 12));
198 //Log(" MM_Map: &PAGETABLE(0) = %x", &PAGETABLE(0));
199 if( !(PAGEMAPLVL4(VAddr >> 39) & 1) )
201 tmp = MM_AllocPhys();
203 PAGEMAPLVL4(VAddr >> 39) = tmp | 3;
204 memset( &PAGEDIRPTR( (VAddr>>39)<<9 ), 0, 4096 );
208 if( !(PAGEDIRPTR(VAddr >> 30) & 1) )
210 tmp = MM_AllocPhys();
212 PAGEDIRPTR(VAddr >> 30) = tmp | 3;
213 memset( &PAGEDIR( (VAddr>>30)<<9 ), 0, 4096 );
217 if( !(PAGEDIR(VAddr >> 21) & 1) )
219 tmp = MM_AllocPhys();
221 PAGEDIR(VAddr >> 21) = tmp | 3;
222 memset( &PAGETABLE( (VAddr>>21)<<9 ), 0, 4096 );
225 // Check if this virtual address is already mapped
226 if( PAGETABLE(VAddr >> PTAB_SHIFT) & 1 )
229 PAGETABLE(VAddr >> PTAB_SHIFT) = PAddr | 3;
231 Log("MM_Map: RETURN 1");
237 * \brief Removed a mapped page
239 void MM_Unmap(tVAddr VAddr)
242 if( !(PAGEMAPLVL4(VAddr >> 39) & 1) ) return ;
244 if( !(PAGEDIRPTR(VAddr >> 30) & 1) ) return ;
246 if( !(PAGEDIR(VAddr >> 21) & 1) ) return ;
248 PAGETABLE(VAddr >> PTAB_SHIFT) = 0;
252 * \brief Allocate a block of memory at the specified virtual address
254 tPAddr MM_Allocate(tVAddr VAddr)
258 Log("MM_Allocate: (VAddr=%x)", VAddr);
259 Log("MM_Allocate: MM_AllocPhys()");
260 ret = MM_AllocPhys();
261 Log("MM_Allocate: ret = %x", ret);
264 if( !MM_Map(VAddr, ret) )
266 Warning("MM_Allocate: Unable to map", ret);
274 void MM_Deallocate(tVAddr VAddr)
278 phys = MM_GetPhysAddr(VAddr);
287 * \brief Get the physical address of a virtual location
289 tPAddr MM_GetPhysAddr(tVAddr Addr)
291 Log("MM_GetPhysAddr: (Addr=0x%x)", Addr);
292 if( !(PAGEMAPLVL4(Addr >> 39) & 1) )
294 Log(" MM_GetPhysAddr: PDP Valid");
295 if( !(PAGEDIRPTR(Addr >> 30) & 1) )
297 Log(" MM_GetPhysAddr: PD Valid");
298 if( !(PAGEDIR(Addr >> 21) & 1) )
300 Log(" MM_GetPhysAddr: PT Valid");
301 if( !(PAGETABLE(Addr >> PTAB_SHIFT) & 1) )
303 Log(" MM_GetPhysAddr: Page Valid");
305 return (PAGETABLE(Addr >> PTAB_SHIFT) & ~0xFFF) | (Addr & 0xFFF);
309 * \brief Sets the flags on a page
311 void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
316 if( !(PAGEMAPLVL4(VAddr >> 39) & 1) )
318 if( !(PAGEDIRPTR(VAddr >> 30) & 1) )
320 if( !(PAGEDIR(VAddr >> 21) & 1) )
322 if( !(PAGETABLE(VAddr >> 12) & 1) )
326 ent = &PAGETABLE(VAddr >> 12);
329 if( Mask & MM_PFLAG_RO )
331 if( Flags & MM_PFLAG_RO ) {
340 if( Mask & MM_PFLAG_KERNEL )
342 if( Flags & MM_PFLAG_KERNEL ) {
351 if( Mask & MM_PFLAG_COW )
353 if( Flags & MM_PFLAG_COW ) {
364 if( Mask & MM_PFLAG_EXEC )
366 if( Flags & MM_PFLAG_EXEC ) {
376 * \brief Get the flags applied to a page
378 Uint MM_GetFlags(tVAddr VAddr)
384 if( !(PAGEMAPLVL4(VAddr >> 39) & 1) )
386 if( !(PAGEDIRPTR(VAddr >> 30) & 1) )
388 if( !(PAGEDIR(VAddr >> 21) & 1) )
390 if( !(PAGETABLE(VAddr >> 12) & 1) )
394 ent = &PAGETABLE(VAddr >> 12);
397 if( !(*ent & PF_WRITE) ) ret |= MM_PFLAG_RO;
399 if( !(*ent & PF_USER) ) ret |= MM_PFLAG_KERNEL;
401 if( *ent & PF_COW ) ret |= MM_PFLAG_COW;
403 if( !(*ent & PF_NX) ) ret |= MM_PFLAG_EXEC;
408 // --- Hardware Mappings ---
410 * \brief Map a range of hardware pages
412 tVAddr MM_MapHWPages(tPAddr PAddr, Uint Number)
414 Log_KernelPanic("MM", "TODO: Implement MM_MapHWPages");
419 * \brief Free a range of hardware pages
421 void MM_UnmapHWPages(tVAddr VAddr, Uint Number)
423 Log_KernelPanic("MM", "TODO: Implement MM_UnmapHWPages");
426 // --- Tempory Mappings ---
427 tVAddr MM_MapTemp(tPAddr PAddr)
429 Log_KernelPanic("MM", "TODO: Implement MM_MapTemp");
433 void MM_FreeTemp(tVAddr VAddr)
435 Log_KernelPanic("MM", "TODO: Implement MM_FreeTemp");
440 // --- Address Space Clone --
441 tPAddr MM_Clone(void)
445 // #1 Create a copy of the PML4
446 ret = MM_AllocPhys();
449 // #2 Alter the fractal pointer
450 // #3 Set Copy-On-Write to all user pages
455 void MM_ClearUser(void)
458 // #1 Traverse the structure < 2^47, Deref'ing all pages
459 // #2 Free tables/dirs/pdps once they have been cleared
461 for( addr = 0; addr < 0x800000000000; )
463 if( PAGEMAPLVL4(addr >> PML4_SHIFT) & 1 )
465 if( PAGEDIRPTR(addr >> PDP_SHIFT) & 1 )
467 if( PAGEDIR(addr >> PDIR_SHIFT) & 1 )
470 if( PAGETABLE(addr >> PTAB_SHIFT) & 1 ) {
471 MM_DerefPhys( PAGETABLE(addr >> PTAB_SHIFT) & PADDR_MASK );
472 PAGETABLE(addr >> PTAB_SHIFT) = 0;
474 addr += 1 << PTAB_SHIFT;
475 // Dereference the PDIR Entry
476 if( (addr + (1 << PTAB_SHIFT)) >> PDIR_SHIFT != (addr >> PDIR_SHIFT) ) {
477 MM_DerefPhys( PAGEMAPLVL4(addr >> PDIR_SHIFT) & PADDR_MASK );
478 PAGEDIR(addr >> PDIR_SHIFT) = 0;
482 addr += 1 << PDIR_SHIFT;
485 // Dereference the PDP Entry
486 if( (addr + (1 << PDIR_SHIFT)) >> PDP_SHIFT != (addr >> PDP_SHIFT) ) {
487 MM_DerefPhys( PAGEMAPLVL4(addr >> PDP_SHIFT) & PADDR_MASK );
488 PAGEDIRPTR(addr >> PDP_SHIFT) = 0;
492 addr += 1 << PDP_SHIFT;
495 // Dereference the PML4 Entry
496 if( (addr + (1 << PDP_SHIFT)) >> PML4_SHIFT != (addr >> PML4_SHIFT) ) {
497 MM_DerefPhys( PAGEMAPLVL4(addr >> PML4_SHIFT) & PADDR_MASK );
498 PAGEMAPLVL4(addr >> PML4_SHIFT) = 0;
502 addr += (tVAddr)1 << PML4_SHIFT;
508 tVAddr MM_NewWorkerStack(void)
513 tVAddr MM_NewKStack(void)