*
* Physical Memory Manager
*/
+#define DEBUG 0
#include <acess.h>
#include <mboot.h>
#include <mm_virt.h>
};
// === IMPORTS ===
+extern void gKernelBase;
extern void gKernelEnd;
+// === PROTOTYPES ===
+void MM_InitPhys_Multiboot(tMBoot_Info *MBoot);
+tPAddr MM_AllocPhysRange(int Num, int Bits);
+tPAddr MM_AllocPhys(void);
+void MM_RefPhys(tPAddr PAddr);
+void MM_DerefPhys(tPAddr PAddr);
+ int MM_int_GetRangeID( tPAddr Addr );
+
// === GLOBALS ===
tSpinlock glPhysicalPages;
-Uint64 *gaSuperBitmap; // 1 bit = 64 Pages
-Uint64 *gaMainBitmap; // 1 bit = 1 Page
+Uint64 *gaSuperBitmap; // 1 bit = 64 Pages, 16 MiB Per Word
+Uint64 *gaMainBitmap; // 1 bit = 1 Page, 256 KiB per Word
Uint64 *gaMultiBitmap; // Each bit means that the page is being used multiple times
Uint32 *gaiPageReferences = (void*)MM_PAGE_COUNTS; // Reference Counts
tPAddr giFirstFreePage; // First possibly free page
Uint64 giPhysRangeFirst[NUM_MM_PHYS_RANGES]; // First free page in each range
Uint64 giPhysRangeLast[NUM_MM_PHYS_RANGES]; // Last free page in each range
Uint64 giMaxPhysPage = 0; // Maximum Physical page
+// Only used in init, allows the init code to provide pages for use by
+// the allocator before the bitmaps exist.
+// 3 entries because the are three calls to MM_AllocPhys in MM_Map
+#define NUM_STATIC_ALLOC 3
+tPAddr gaiStaticAllocPages[NUM_STATIC_ALLOC] = {0};
// === CODE ===
+/**
+ * \brief Initialise the physical memory map using a Multiboot 1 map
+ */
void MM_InitPhys_Multiboot(tMBoot_Info *MBoot)
{
tMBoot_MMapEnt *mmapStart;
tMBoot_MMapEnt *ent;
Uint64 maxAddr = 0;
- int numPages;
- int superPages;
+ int numPages, superPages;
+ int i;
+ Uint64 base, size;
+ tVAddr vaddr;
+ tPAddr paddr, firstFreePage;
- Log("MM_InitPhys_Multiboot: (MBoot=%p)", MBoot);
+ ENTER("pMBoot=%p", MBoot);
// Scan the physical memory map
// Looking for the top of physical memory
mmapStart = (void *)( KERNEL_BASE | MBoot->MMapAddr );
- Log(" MM_InitPhys_Multiboot: mmapStart = %p", mmapStart);
+ LOG("mmapStart = %p", mmapStart);
ent = mmapStart;
while( (Uint)ent < (Uint)mmapStart + MBoot->MMapLength )
{
// Adjust for the size of the entry
ent->Size += 4;
- Log(" MM_InitPhys_Multiboot: ent={Type:%i,Base:0x%x,Length:%x",
+ LOG("ent={Type:%i,Base:0x%x,Length:%x",
ent->Type, ent->Base, ent->Length);
// If entry is RAM and is above `maxAddr`, change `maxAddr`
// Goodie, goodie gumdrops
giMaxPhysPage = maxAddr >> 12;
}
- Log(" MM_InitPhys_Multiboot: giMaxPhysPage = 0x%x", giMaxPhysPage);
+ LOG("giMaxPhysPage = 0x%x", giMaxPhysPage);
// Find a contigous section of memory to hold it in
// - Starting from the end of the kernel
superPages = ((giMaxPhysPage+64*8-1)/(64*8) + 0xFFF) >> 12;
numPages = (giMaxPhysPage + 7) / 8;
numPages = (numPages + 0xFFF) >> 12;
- Log(" MM_InitPhys_Multiboot: numPages = %i", numPages);
+ LOG("numPages = %i, superPages = %i", numPages, superPages);
if(maxAddr == 0)
{
- int todo = numPages;
+ int todo = numPages*2 + superPages;
// Ok, naieve allocation, just put it after the kernel
// - Allocated Bitmap
- tVAddr vaddr = MM_PAGE_BITMAP;
- tPAddr paddr = (tPAddr)&gKernelEnd - KERNEL_BASE;
- while(todo --)
+ vaddr = MM_PAGE_BITMAP;
+ paddr = (tPAddr)&gKernelEnd - KERNEL_BASE;
+ while(todo )
{
+ // Allocate statics
+ for( i = 0; i < NUM_STATIC_ALLOC; i++) {
+ if(gaiStaticAllocPages[i] != 0) continue;
+ gaiStaticAllocPages[i] = paddr;
+ paddr += 0x1000;
+ }
+
MM_Map(vaddr, paddr);
vaddr += 0x1000;
paddr += 0x1000;
- }
- // - Multi-Alloc Bitmap
- vaddr = MM_PAGE_DBLBMP;
- todo = numPages;
- while(todo --) {
- MM_Map(vaddr, paddr);
- vaddr += 0x1000;
- paddr += 0x1000;
- }
- // - Super Bitmap
- vaddr = MM_PAGE_SUPBMP;
- todo = superPages;
- while(todo --) {
- MM_Map(vaddr, paddr);
- vaddr += 0x1000;
- paddr += 0x1000;
+
+ todo --;
+
+ if( todo == numPages + superPages )
+ vaddr = MM_PAGE_DBLBMP;
+ if( todo == superPages )
+ vaddr = MM_PAGE_SUPBMP;
}
}
// Scan for a nice range
else
{
int todo = numPages*2 + superPages;
- tPAddr paddr = 0;
- tVAddr vaddr = MM_PAGE_BITMAP;
+ paddr = 0;
+ vaddr = MM_PAGE_BITMAP;
// Scan!
for(
ent = mmapStart;
)
{
int avail;
- int i, max;
// RAM only please
if( ent->Type != 1 )
continue;
// Let's not put it below the kernel, shall we?
- if( ent->Base + ent->Size < (tPAddr)&gKernelEnd )
+ if( ent->Base + ent->Size < (tPAddr)&gKernelBase )
continue;
+ LOG("%x <= %x && %x > %x",
+ ent->Base, (tPAddr)&gKernelBase,
+ ent->Base + ent->Size, (tPAddr)&gKernelEnd - KERNEL_BASE
+ );
// Check if the kernel is in this range
- if( ent->Base < (tPAddr)&gKernelEnd - KERNEL_BASE && ent->Base + ent->Size > (tPAddr)&gKernelEnd )
+ if( ent->Base <= (tPAddr)&gKernelBase
+ && ent->Base + ent->Length > (tPAddr)&gKernelEnd - KERNEL_BASE )
{
- avail = (ent->Size-((tPAddr)&gKernelEnd-KERNEL_BASE-ent->Base)) >> 12;
+ avail = ent->Length >> 12;
+ avail -= ((tPAddr)&gKernelEnd - KERNEL_BASE - ent->Base) >> 12;
paddr = (tPAddr)&gKernelEnd - KERNEL_BASE;
}
// No? then we can use all of the block
else
{
- avail = ent->Size >> 12;
+ avail = ent->Length >> 12;
paddr = ent->Base;
}
+ Log(" MM_InitPhys_Multiboot: paddr=0x%x, avail=%i", paddr, avail);
+
// Map
- max = todo < avail ? todo : avail;
- for( i = 0; i < max; i ++ )
+ while( todo && avail --)
{
+ // Static Allocations
+ for( i = 0; i < NUM_STATIC_ALLOC && avail; i++) {
+ if(gaiStaticAllocPages[i] != 0) continue;
+ gaiStaticAllocPages[i] = paddr;
+ paddr += 0x1000;
+ avail --;
+ }
+ if(!avail) break;
+
+ // Map
MM_Map(vaddr, paddr);
todo --;
vaddr += 0x1000;
paddr += 0x1000;
+
+ // Alter the destination address when needed
+ if(todo == superPages+numPages)
+ vaddr = MM_PAGE_DBLBMP;
+ if(todo == superPages)
+ vaddr = MM_PAGE_SUPBMP;
}
- // Alter the destination address when needed
- if(todo == superPages+numPages)
- vaddr = MM_PAGE_DBLBMP;
- if(todo == superPages)
- vaddr = MM_PAGE_SUPBMP;
// Fast quit if there's nothing left to allocate
if( !todo ) break;
}
}
+ // Save the current value of paddr to simplify the allocation later
+ firstFreePage = paddr;
+ LOG("Clearing multi bitmap");
// Fill the bitmaps
+ memset(gaMultiBitmap, 0, numPages<<12);
// - initialise to one, then clear the avaliable areas
- memset(gaSuperBitmap, -1, superPages<<12);
memset(gaMainBitmap, -1, numPages<<12);
- memset(gaMultiBitmap, 0, numPages<<12);
+ LOG("Setting main bitmap");
// - Clear all Type=1 areas
+ LOG("Clearing valid regions");
for(
ent = mmapStart;
(Uint)ent < (Uint)mmapStart + MBoot->MMapLength;
ent = (tMBoot_MMapEnt *)( (Uint)ent + ent->Size )
)
{
- Uint64 base, size;
// Check if the type is RAM
if(ent->Type != 1) continue;
size -= (base & 63);
base += 64 - (base & 63);
}
- memset( &gaSuperBitmap[base / 64], 0, size/8 );
- if( size & 7 ) {
- Uint64 val = -1 << (size & 7);
- val <<= (size/8)&7;
- gaSuperBitmap[base / 64] &= ~val;
- }
}
// Reference the used pages
- // - Kernel
- // - Reference Counts and Bitmap
+ base = (tPAddr)&gKernelBase >> 12;
+ size = firstFreePage >> 12;
+ memset( &gaMainBitmap[base / 64], -1, size/8 );
+ if( size & 7 ) {
+ Uint64 val = -1 << (size & 7);
+ val <<= (size/8)&7;
+ gaMainBitmap[base / 64] |= val;
+ }
+
+ // Free the unused static allocs
+ for( i = 0; i < NUM_STATIC_ALLOC; i++) {
+ if(gaiStaticAllocPages[i] != 0)
+ continue;
+ gaMainBitmap[ gaiStaticAllocPages[i] >> (12+6) ]
+ &= ~(1 << ((gaiStaticAllocPages[i]>>12)&63));
+ }
+
+ // Fill the super bitmap
+ LOG("Filling super bitmap");
+ memset(gaSuperBitmap, 0, superPages<<12);
+ for( base = 0; base < (size+63)/64; base ++)
+ {
+ if( gaMainBitmap[ base ] == -1 )
+ gaSuperBitmap[ base/64 ] |= 1 << (base&63);
+ }
+
+ // Set free page counts
+ for( base = 1; base < giMaxPhysPage; base ++ )
+ {
+ int rangeID;
+ // Skip allocated
+ if( gaMainBitmap[ base >> 6 ] & (1 << (base&63)) ) continue;
+
+ // Get range ID
+ rangeID = MM_int_GetRangeID( base << 12 );
+
+ // Increment free page count
+ giPhysRangeFree[ rangeID ] ++;
+
+ // Check for first free page in range
+ if(giPhysRangeFirst[ rangeID ] == 0)
+ giPhysRangeFirst[ rangeID ] = base;
+ // Set last (when the last free page is reached, this won't be
+ // updated anymore, hence will be correct)
+ giPhysRangeLast[ rangeID ] = base;
+ }
+
+ LEAVE('-');
}
/**
*/
tPAddr MM_AllocPhysRange(int Num, int Bits)
{
- tPAddr addr;
+ tPAddr addr, ret;
int rangeID;
int nFree = 0, i;
- Log("MM_AllocPhysRange: (Num=%i,Bits=%i)", Num, Bits);
+ ENTER("iNum iBits", Num, Bits);
- if( Bits <= 0 ) // Speedup for the common case
+ if( Bits <= 0 || Bits >= 64 ) // Speedup for the common case
rangeID = MM_PHYS_MAX;
- else if( Bits > 32 )
- rangeID = MM_PHYS_MAX;
- else if( Bits > 24 )
- rangeID = MM_PHYS_32BIT;
- else if( Bits > 20 )
- rangeID = MM_PHYS_24BIT;
- else if( Bits > 16 )
- rangeID = MM_PHYS_20BIT;
else
- rangeID = MM_PHYS_16BIT;
+ rangeID = MM_int_GetRangeID( (1 << Bits) -1 );
- Log(" MM_AllocPhysRange: rangeID = %i", rangeID);
+ LOG("rangeID = %i", rangeID);
LOCK(&glPhysicalPages);
- Log(" MM_AllocPhysRange: i has lock");
// Check if the range actually has any free pages
while(giPhysRangeFree[rangeID] == 0 && rangeID)
rangeID --;
- Log(" MM_AllocPhysRange: rangeID = %i", rangeID);
+ LOG("rangeID = %i", rangeID);
// What the? Oh, man. No free pages
if(giPhysRangeFree[rangeID] == 0) {
"Out of memory (unable to fulfil request for %i pages), zero remaining",
Num
);
+ LEAVE('i', 0);
return 0;
}
// Check if there is enough in the range
if(giPhysRangeFree[rangeID] >= Num)
{
+ LOG("{%i,0x%x -> 0x%x}",
+ giPhysRangeFree[rangeID],
+ giPhysRangeFirst[rangeID], giPhysRangeLast[rangeID]
+ );
// Do a cheap scan, scanning upwards from the first free page in
// the range
- nFree = 1;
+ nFree = 0;
addr = giPhysRangeFirst[ rangeID ];
- while( addr < giPhysRangeLast[ rangeID ] )
+ while( addr <= giPhysRangeLast[ rangeID ] )
{
+ //Log(" MM_AllocPhysRange: addr = 0x%x", addr);
// Check the super bitmap
if( gaSuperBitmap[addr >> (6+6)] == -1 ) {
+ LOG("nFree = %i = 0 (super) (0x%x)", nFree, addr);
nFree = 0;
addr += 1 << (6+6);
addr &= (1 << (6+6)) - 1;
}
// Check page block (64 pages)
if( gaSuperBitmap[addr >> (6+6)] & (1 << (addr>>6)&63)) {
+ LOG("nFree = %i = 0 (main) (0x%x)", nFree, addr);
nFree = 0;
addr += 1 << (12+6);
addr &= (1 << (12+6)) - 1;
}
// Check individual page
if( gaMainBitmap[addr >> 6] & (1 << (addr & 63)) ) {
+ LOG("nFree = %i = 0 (page) (0x%x)", nFree, addr);
nFree = 0;
addr ++;
continue;
}
nFree ++;
addr ++;
+ LOG("nFree(%i) == %i (0x%x)", nFree, Num, addr);
if(nFree == Num)
break;
}
+ LOG("nFree = %i", nFree);
// If we don't find a contiguous block, nFree will not be equal
// to Num, so we set it to zero and do the expensive lookup.
if(nFree != Num) nFree = 0;
RELEASE(&glPhysicalPages);
// TODO: Page out
// ATM. Just Warning
+ Warning(" MM_AllocPhysRange: Out of memory (unable to fulfil request for %i pages)", Num);
Log_Warning("Arch",
"Out of memory (unable to fulfil request for %i pages)",
Num
);
+ LEAVE('i', 0);
return 0;
}
- Log(" MM_AllocPhysRange: nFree = %i, addr = 0x%08x", nFree, addr);
+ LOG("nFree = %i, addr = 0x%08x", nFree, addr);
// Mark pages as allocated
addr -= Num;
- for( i = 0; i < Num; i++ )
+ for( i = 0; i < Num; i++, addr++ )
{
- gaiPageReferences[addr >> 6] |= 1 << (addr & 63);
-
- if(addr >> 32) rangeID = MM_PHYS_MAX;
- else if(addr >> 24) rangeID = MM_PHYS_32BIT;
- else if(addr >> 20) rangeID = MM_PHYS_24BIT;
- else if(addr >> 16) rangeID = MM_PHYS_20BIT;
- else if(addr >> 0) rangeID = MM_PHYS_16BIT;
+ gaMainBitmap[addr >> 6] |= 1 << (addr & 63);
+ rangeID = MM_int_GetRangeID(addr);
giPhysRangeFree[ rangeID ] --;
}
- // Fill super bitmap
+ ret = addr; // Save the return address
+
+ // Update super bitmap
Num += addr & (64-1);
addr &= ~(64-1);
Num = (Num + (64-1)) & ~(64-1);
}
RELEASE(&glPhysicalPages);
- return addr << 12;
+ LEAVE('x', ret << 12);
+ return ret << 12;
}
/**
*/
tPAddr MM_AllocPhys(void)
{
+ int i;
+
+ // Hack to allow allocation during setup
+ for(i = 0; i < NUM_STATIC_ALLOC; i++) {
+ if( gaiStaticAllocPages[i] ) {
+ tPAddr ret = gaiStaticAllocPages[i];
+ gaiStaticAllocPages[i] = 0;
+ Log("MM_AllocPhys: Return %x, static alloc %i", ret, i);
+ return ret;
+ }
+ }
+
return MM_AllocPhysRange(1, -1);
}
else
gaMainBitmap[ page >> 6 ] &= ~(1 << (page&63));
+ // TODO: Update free counts
+ if( !(gaMainBitmap[ page >> 6 ] & (1 << (page&63))) )
+ {
+ int rangeID;
+ rangeID = MM_int_GetRangeID( PAddr );
+ giPhysRangeFree[ rangeID ] ++;
+ }
+
if(gaMainBitmap[ page >> 6 ] == 0) {
gaSuperBitmap[page >> 12] &= ~(1 << ((page >> 6) & 63));
}
}
+
+/**
+ * \brief Takes a physical address and returns the ID of its range
+ * \param Addr Physical address of page
+ * \return Range ID from eMMPhys_Ranges
+ */
+int MM_int_GetRangeID( tPAddr Addr )
+{
+ if(Addr >> 32)
+ return MM_PHYS_MAX;
+ else if(Addr >> 24)
+ return MM_PHYS_32BIT;
+ else if(Addr >> 20)
+ return MM_PHYS_24BIT;
+ else if(Addr >> 16)
+ return MM_PHYS_20BIT;
+ else
+ return MM_PHYS_16BIT;
+}