/*
- AcessOS Microkernel Version
- mm_phys.c
-*/
-#include <common.h>
+ * Acess2
+ * - Physical memory manager
+ */
+#define DEBUG 0
+#include <acess.h>
#include <mboot.h>
#include <mm_virt.h>
+#define USE_STACK 1
+
#define REFERENCE_BASE 0xE0400000
// === IMPORTS ===
extern void gKernelEnd;
// === PROTOTYPES ===
-Uint32 MM_AllocPhys();
-void MM_RefPhys(Uint32 Addr);
-void MM_DerefPhys(Uint32 Addr);
+tPAddr MM_AllocPhys();
+tPAddr MM_AllocPhysRange(int Pages, int MaxBits);
+void MM_RefPhys(tPAddr Addr);
+void MM_DerefPhys(tPAddr Addr);
// === GLOBALS ===
- int giPhysAlloc = 0;
-Uint giPageCount = 0;
+Uint64 giPhysAlloc = 0; // Number of allocated pages
+Uint64 giPageCount = 0; // Total number of pages
+Uint64 giLastPossibleFree = 0; // Last possible free page (before all pages are used)
+
Uint32 gaSuperBitmap[1024]; // Blocks of 1024 Pages
Uint32 gaPageBitmap[1024*1024/32]; // Individual pages
Uint32 *gaPageReferences;
{
Uint kernelPages, num;
Uint i;
+ Uint64 maxAddr = 0;
tMBoot_Module *mods;
+ tMBoot_MMapEnt *ent;
- // Initialise globals
- giPageCount = (MBoot->HighMem >> 2) + 256; // HighMem is a kByte value
- Log("giPageCount = %i", giPageCount);
+ // --- Find largest address
+ MBoot->MMapAddr |= KERNEL_BASE;
+ ent = (void *)( MBoot->MMapAddr );
+ while( (Uint)ent < MBoot->MMapAddr + MBoot->MMapLength )
+ {
+ // Adjust for size
+ ent->Size += 4;
+
+ // If entry is RAM and is above `maxAddr`, change `maxAddr`
+ if(ent->Type == 1 && ent->Base + ent->Length > maxAddr)
+ maxAddr = ent->Base + ent->Length;
+ // Go to next entry
+ ent = (tMBoot_MMapEnt *)( (Uint)ent + ent->Size );
+ }
+
+ if(maxAddr == 0) {
+ giPageCount = (MBoot->HighMem >> 2) + 256; // HighMem is a kByte value
+ }
+ else {
+ giPageCount = maxAddr >> 12;
+ }
+ giLastPossibleFree = giPageCount - 1;
+
+ memsetd(gaPageBitmap, 0xFFFFFFFF, giPageCount/32);
+
+ // Set up allocateable space
+ ent = (void *)( MBoot->MMapAddr );
+ while( (Uint)ent < MBoot->MMapAddr + MBoot->MMapLength )
+ {
+ memsetd( &gaPageBitmap[ent->Base/(4096*32)], 0, ent->Length/(4096*32) );
+ ent = (tMBoot_MMapEnt *)( (Uint)ent + ent->Size );
+ }
// Get used page count
- kernelPages = (Uint)&gKernelEnd - KERNEL_BASE;
+ kernelPages = (Uint)&gKernelEnd - KERNEL_BASE - 0x100000;
kernelPages += 0xFFF; // Page Align
kernelPages >>= 12;
// Fill page bitmap
num = kernelPages/32;
- memsetd(gaPageBitmap, -1, num);
- gaPageBitmap[ num ] = (1 << (kernelPages & 31)) - 1;
+ memsetd( &gaPageBitmap[0x100000/(4096*32)], -1, num );
+ gaPageBitmap[ 0x100000/(4096*32) + num ] = (1 << (kernelPages & 31)) - 1;
// Fill Superpage bitmap
num = kernelPages/(32*32);
- memsetd(gaSuperBitmap, -1, num);
- gaSuperBitmap[ num ] = (1 << ((kernelPages / 32) & 31)) - 1;
+ memsetd( &gaSuperBitmap[0x100000/(4096*32*32)], -1, num );
+ gaSuperBitmap[ 0x100000/(4096*32*32) + num ] = (1 << ((kernelPages / 32) & 31)) - 1;
// Mark Multiboot's pages as taken
// - Structure
}
// Allocate References
- Log("Reference Pages %i", (giPageCount*4+0xFFF)>>12);
+ //LOG("Reference Pages %i", (giPageCount*4+0xFFF)>>12);
for(num = 0; num < (giPageCount*4+0xFFF)>>12; num++)
{
MM_Allocate( REFERENCE_BASE + (num<<12) );
}
+ //LOG("Filling");
// Fill references
gaPageReferences = (void*)REFERENCE_BASE;
memsetd(gaPageReferences, 1, kernelPages);
/**
* \fn tPAddr MM_AllocPhys()
- * \brief Allocates a physical page
+ * \brief Allocates a physical page from the general pool
*/
tPAddr MM_AllocPhys()
{
- int num = giPageCount / 32 / 32;
- int a, b, c;
- Uint32 ret;
+ // int a, b, c;
+ int indx;
+ tPAddr ret;
+
+ ENTER("");
LOCK( &giPhysAlloc );
// Find free page
- for(a=0;gaSuperBitmap[a]==-1&&a<num;a++);
- if(a == num) {
+ // Scan downwards
+ #if 1
+ LOG("giLastPossibleFree = %i", giLastPossibleFree);
+ for( indx = giLastPossibleFree; indx >= 0; )
+ {
+ if( gaSuperBitmap[indx>>10] == -1 ) {
+ indx -= 1024;
+ continue;
+ }
+ if( gaPageBitmap[indx>>5] == -1 ) {
+ indx -= 32;
+ continue;
+ }
+
+ if( gaPageBitmap[indx>>5] & (1 << (indx&31)) ) {
+ indx --;
+ continue;
+ }
+ break;
+ }
+ LOG("indx = %i", indx);
+ #else
+ c = giLastPossibleFree % 32;
+ b = (giLastPossibleFree / 32) % 32;
+ a = giLastPossibleFree / 1024;
+
+ LOG("a=%i,b=%i,c=%i", a, b, c);
+ for( ; gaSuperBitmap[a] == -1 && a >= 0; a-- );
+ if(a < 0) {
RELEASE( &giPhysAlloc );
Warning("MM_AllocPhys - OUT OF MEMORY (Called by %p)", __builtin_return_address(0));
+ LEAVE('i', 0);
return 0;
}
- for(b=0;gaSuperBitmap[a]&(1<<b);b++);
- for(c=0;gaPageBitmap[a*32+b]&(1<<c);c++);
- //for(c=0;gaPageReferences[a*32*32+b*32+c]>0;c++);
+ for( ; gaSuperBitmap[a] & (1<<b); b-- );
+ for( ; gaPageBitmap[a*32+b] & (1<<c); c-- );
+ LOG("a=%i,b=%i,c=%i", a, b, c);
+ indx = (a << 10) | (b << 5) | c;
+ #endif
// Mark page used
if(gaPageReferences)
- gaPageReferences[a*32*32+b*32+c] = 1;
- gaPageBitmap[ a*32+b ] |= 1 << c;
+ gaPageReferences[ indx ] = 1;
+ gaPageBitmap[ indx>>5 ] |= 1 << (indx&31);
+
// Get address
- ret = (a << 22) + (b << 17) + (c << 12);
+ ret = indx << 12;
+ giLastPossibleFree = indx;
// Mark used block
- if(gaPageBitmap[ a*32+b ] == -1) gaSuperBitmap[a] |= 1 << b;
+ if(gaPageBitmap[ indx>>5 ] == -1)
+ gaSuperBitmap[indx>>10] |= 1 << ((indx>>5)&31);
// Release Spinlock
RELEASE( &giPhysAlloc );
- //LOG("ret = %x", ret);
+
+ LEAVE('X', ret);
+ //Log("MM_AllocPhys: RETURN 0x%x", ret);
+ return ret;
+}
+
+/**
+ * \fn tPAddr MM_AllocPhysRange(int Pages, int MaxBits)
+ * \brief Allocate a range of physical pages
+ * \param Pages Number of pages to allocate
+ * \param MaxBits Maximum number of address bits to use
+ */
+tPAddr MM_AllocPhysRange(int Pages, int MaxBits)
+{
+ int a, b;
+ int i, idx, sidx;
+ tPAddr ret;
+
+ // Sanity Checks
+ if(MaxBits < 0) return 0;
+ if(MaxBits > PHYS_BITS) MaxBits = PHYS_BITS;
+
+ // Lock
+ LOCK( &giPhysAlloc );
+
+ // Set up search state
+ if( giLastPossibleFree > ((tPAddr)1 << (MaxBits-12)) ) {
+ sidx = (tPAddr)1 << (MaxBits-12);
+ }
+ else {
+ sidx = giLastPossibleFree;
+ }
+ idx = sidx / 32;
+ sidx %= 32;
+ b = idx % 32;
+ a = idx / 32;
+
+ // Find free page
+ for( ; gaSuperBitmap[a] == -1 && a --; );
+ if(a < 0) {
+ RELEASE( &giPhysAlloc );
+ Warning("MM_AllocPhysRange - OUT OF MEMORY (Called by %p)", __builtin_return_address(0));
+ return 0;
+ }
+ for( ; gaSuperBitmap[a] & (1 << b); b-- );
+ idx = a * 32 + b;
+ for( ; gaPageBitmap[idx] & (1 << sidx); sidx-- );
+
+ // Check if the gap is large enough
+ while( idx >= 0 )
+ {
+ // Find a free page
+ for( ; ; )
+ {
+ // Bulk Skip
+ if( gaPageBitmap[idx] == -1 ) {
+ idx --;
+ sidx = 31;
+ continue;
+ }
+
+ if( gaPageBitmap[idx] & (1 << sidx) ) {
+ sidx --;
+ if(sidx < 0) { sidx = 31; idx --; }
+ if(idx < 0) break;
+ continue;
+ }
+ break;
+ }
+ if( idx < 0 ) break;
+
+ // Check if it is a free range
+ for( i = 0; i < Pages; i++ )
+ {
+ // Used page? break
+ if( gaPageBitmap[idx] & (1 << sidx) )
+ break;
+
+ sidx --;
+ if(sidx < 0) { sidx = 31; idx --; }
+ if(idx < 0) break;
+ }
+
+ if( i == Pages )
+ break;
+ }
+
+ // Check if an address was found
+ if( idx < 0 ) {
+ RELEASE( &giPhysAlloc );
+ Warning("MM_AllocPhysRange - OUT OF MEMORY (Called by %p)", __builtin_return_address(0));
+ }
+
+ // Mark pages used
+ for( i = 0; i < Pages; i++ )
+ {
+ if(gaPageReferences)
+ gaPageReferences[idx*32+sidx] = 1;
+ gaPageBitmap[ idx ] |= 1 << sidx;
+ sidx ++;
+ if(sidx == 32) { sidx = 0; idx ++; }
+ }
+
+ // Get address
+ ret = (idx << 17) | (sidx << 12);
+
+ // Mark used block
+ if(gaPageBitmap[ idx ] == -1) gaSuperBitmap[idx/32] |= 1 << (idx%32);
+
+ // Release Spinlock
+ RELEASE( &giPhysAlloc );
+
return ret;
}
// Mark as free in bitmaps
if( gaPageReferences[ Addr ] == 0 )
{
+ //LOG("Freed 0x%x by %p\n", Addr<<12, __builtin_return_address(0));
gaPageBitmap[ Addr / 32 ] &= ~(1 << (Addr&31));
if(gaPageReferences[ Addr ] == 0)
gaSuperBitmap[ Addr >> 10 ] &= ~(1 << ((Addr >> 5)&31));