Files
bsb2/kernel/memory/pageframealloc.cc

153 lines
4.6 KiB
C++

#include "../memory/pageframealloc.h"
#include "../boot/multiboot/data.h"
#include "page.h"
#include "pageframe.h"
#include "../debug/output.h"
#include "../memory/config.h"
#include "../arch/lapic.h"
#include "../arch/apic.h"
//uint8_t PageFrameAllocator::bitmap[4294967296 / 4096 / 8];
PageFrame PageFrameAllocator::PageFrames[4294967296 / 4096];
Queue<PageFrame> user_memory_q;
Queue<PageFrame> kernel_memory_q;
void mark_pageframes(uintptr_t start, uintptr_t end, bool available){
// DBG << "start: " << hex << start << " end: " << end;
start = Page::floor(start);
end = Page::ceil(end);
if(start > 4294967296)
start = 4294967296;
if(end > 4294967296)
end = 4294967296;
if(start < 0x4000000 && end > 0x4000000){
mark_pageframes(start, 0x4000000, available);
mark_pageframes(0x4000000, end, available);
}
//DBG << " page start: " << hex << start << " end: " << end << endl;
Queue<PageFrame>* q = start<0x4000000?&kernel_memory_q:&user_memory_q;
for(uint64_t i = start; i < end; i += 4096){
uint64_t pg = i/4096;
PageFrameAllocator::PageFrames[pg].available = available;
if(available)
q->enqueue(PageFrameAllocator::PageFrames[pg]);
else
q->remove(&PageFrameAllocator::PageFrames[pg]);
}
}
void PageFrameAllocator::init(){
Multiboot::Memory* memory_map_start = Multiboot::getMemoryMap();
Multiboot::Memory* memory_map_entry = memory_map_start;
//mark as available
while(memory_map_entry != 0){
uintptr_t start = (uintptr_t)memory_map_entry->getStartAddress();
uintptr_t end = (uintptr_t)memory_map_entry->getEndAddress();
bool available = memory_map_entry->isAvailable();
if(available){
if(start < (uintptr_t)&___KERNEL_END___)
start = Page::ceil((uintptr_t)&___KERNEL_END___ +1);
mark_pageframes(start, end, available);
}
memory_map_entry = memory_map_entry->getNext();
}
//mark as unavailable
memory_map_entry = memory_map_start;
while(memory_map_entry != 0){
uintptr_t start = (uintptr_t)memory_map_entry->getStartAddress();
uintptr_t end = (uintptr_t)memory_map_entry->getEndAddress();
bool available = memory_map_entry->isAvailable();
if(!available){
mark_pageframes(start, end, available);
}
memory_map_entry = memory_map_entry->getNext();
}
Multiboot::Module* mod = Multiboot::getModule(0);
mark_pageframes((uintptr_t)mod, (uintptr_t)mod+1, false);
mark_pageframes((uintptr_t)mod->getStartAddress(), (uintptr_t)mod->getEndAddress(), false);
//mark other known regions as unavailable
mark_pageframes((uintptr_t)&___KERNEL_START___, (uintptr_t)&___KERNEL_END___, false);
mark_pageframes(0x00F00000, 0x00FFFFFF, false);
mark_pageframes(0xfee00000, 0xfee003f0, false);
mark_pageframes(APIC::getIOAPICAddress(), APIC::getIOAPICAddress()+0x10, false);
}
void PageFrameAllocator::stats(){
Multiboot::Memory* memory_map_entry = Multiboot::getMemoryMap();
while(memory_map_entry != 0){
void* start = memory_map_entry->getStartAddress();
void* end = memory_map_entry->getEndAddress();
bool available = memory_map_entry->isAvailable();
DBG << "Memory: " << hex << start << " to " << end << " is available: " << available << "." << endl;
memory_map_entry = memory_map_entry->getNext();
}
uint64_t pages_available = 0;
for(uint64_t i=0; i<(sizeof(PageFrames)/sizeof(PageFrames[0]));i++){
if(PageFrames[i].available)
//if(bitmap[i/8] & (1<<i%8))
pages_available++;
}
for(uint64_t i=0; i < 0x8000000/4096/8; i+=4){
if(i%(64*4) == 0){
DBG << endl << hex << i * 8 * 4096 << " " << flush;
int x,y;
dout.getPos(x,y);
for(uint8_t j=x; j<10; j++){
DBG<<" ";
}
}
if(PageFrames[i].available)
DBG << '#';
else
DBG << '.';
}
DBG << "\npages available: " << dec << pages_available << endl;
}
void* PageFrameAllocator::alloc(bool kernel){
Queue<PageFrame>* q = kernel?&kernel_memory_q:&user_memory_q;
PageFrame* free_pageframe = q->dequeue();
if(!free_pageframe)
return 0;
free_pageframe->available = false;
uintptr_t addr = ((free_pageframe - &PageFrames[0]))<<12;
mark_pageframes(addr, addr+1, false);
return (void*)(addr);
}
void PageFrameAllocator::free(PageFrame* frame){
frame->available = true;
//TODO ref counter etc...
}
void PageFrameAllocator::free(uintptr_t addr){
free(&PageFrames[addr>>12]);
}