+++ /dev/null
-/*
- * Physical memory allocation
- * Copyright (c) 2001,2003,2004 David H. Hovemeyer <daveho@cs.umd.edu>
- * Copyright (c) 2003, Jeffrey K. Hollingsworth <hollings@cs.umd.edu>
- * $Revision: 1.1 $
- *
- * This is free software. You are permitted to use,
- * redistribute, and modify it as specified in the file "COPYING".
- */
-
-#include <geekos/defs.h>
-#include <geekos/ktypes.h>
-#include <geekos/kassert.h>
-#include <geekos/bootinfo.h>
-#include <geekos/gdt.h>
-#include <geekos/screen.h>
-#include <geekos/int.h>
-#include <geekos/malloc.h>
-#include <geekos/string.h>
-#include <geekos/mem.h>
-
-#include <geekos/vmm_sizes.h>
-#include <geekos/serial.h>
-
-/* ----------------------------------------------------------------------
- * Global data
- * ---------------------------------------------------------------------- */
-
-/*
- * List of Page structures representing each page of physical memory.
- */
-struct Page* g_pageList;
-
-/*
- * Number of pages currently available on the freelist.
- */
-uint_t g_freePageCount = 0;
-
-/* ----------------------------------------------------------------------
- * Private data and functions
- * ---------------------------------------------------------------------- */
-
-/*
- * Defined in paging.c
- */
-extern int debugFaults;
-#define Debug(args...) if (debugFaults) Print(args)
-
-/*
- * List of pages available for allocation.
- */
-static struct Page_List s_freeList;
-
-/*
- * Total number of physical pages.
- */
-int unsigned s_numPages;
-
-/*
- * Add a range of pages to the inventory of physical memory.
- */
-static void Add_Page_Range(ulong_t start, ulong_t end, int flags)
-{
- ulong_t addr;
-
- //Print("Start: %u, End: %u\n", (unsigned int)start, (unsigned int)end);
-
- KASSERT(Is_Page_Multiple(start));
- KASSERT(Is_Page_Multiple(end));
- KASSERT(start < end);
-
- //Print("Adding %lu pages\n", (end - start) / PAGE_SIZE);
-
- for (addr = start; addr < end; addr += PAGE_SIZE) {
- // Print("Adding Page at %u\n", (unsigned int)addr);
- struct Page *page = Get_Page(addr);
-
- page->flags = flags;
-
- if (flags == PAGE_AVAIL) {
- /* Add the page to the freelist */
- Add_To_Back_Of_Page_List(&s_freeList, page);
-
- /* Update free page count */
- ++g_freePageCount;
- } else {
- Set_Next_In_Page_List(page, 0);
- Set_Prev_In_Page_List(page, 0);
- }
-
- }
- // Print("%d pages now in freelist\n", g_freePageCount);
-
-}
-
-/* ----------------------------------------------------------------------
- * Public functions
- * ---------------------------------------------------------------------- */
-
-/*
- * The linker defines this symbol to indicate the end of
- * the executable image.
- */
-extern char end;
-
-/*
- * Initialize memory management data structures.
- * Enables the use of Alloc_Page() and Free_Page() functions.
- */
-void Init_Mem(struct Boot_Info* bootInfo)
-{
- ulong_t numPages = bootInfo->memSizeKB >> 2;
- // ulong_t endOfMem = numPages * PAGE_SIZE;
- unsigned numPageListBytes = sizeof(struct Page) * numPages;
- ulong_t pageListAddr;
- ulong_t pageListEnd;
- ulong_t kernEnd;
-
- KASSERT(bootInfo->memSizeKB > 0);
-
- if (bootInfo->memSizeKB != TOP_OF_MEM/1024) {
- PrintBoth("Kernel compiled for %d KB machine, but machine claims %d KB\n",TOP_OF_MEM/1024,bootInfo->memSizeKB);
- if (bootInfo->memSizeKB < TOP_OF_MEM/1024) {
- PrintBoth("Kernel compiled for more memory than machine has. Panicking\n");
- KASSERT(0);
- }
- }
-
- if (0) {
- // if there is not enough memory between START_OF_VM+VM_SIZE and TOP_OF_MEM
- // to store the kernel and kernel structures, we need to panick
- PrintBoth("Kernel is not compiled with sufficient memory above the VM to support the memory\n");
- KASSERT(0);
- }
-
-
- bootInfo->memSizeKB = TOP_OF_MEM / 1024;
-
- /*
- * Before we do anything, switch from setup.asm's temporary GDT
- * to the kernel's permanent GDT.
- */
- Init_GDT();
-
- /*
- * We'll put the list of Page objects right after the end
- * of the kernel, and mark it as "kernel". This will bootstrap
- * us sufficiently that we can start allocating pages and
- * keeping track of them.
- */
-
- // JRL: This is stupid...
- // with large mem sizes the page list overruns into the ISA
- // hole. By blind luck this causes an unrelated assertion failure, otherwise
- // I might never have caught it...
- // We fix it by moving the page list after the kernel heap...
- // For now we'll make our own stupid assumption that the mem size
- // is large enough to accomodate the list in high mem.
-
- PrintBoth("Total Memory Size: %u MBytes\n", bootInfo->memSizeKB/1024);
- PrintBoth("VM Start: %x\n",START_OF_VM);
- PrintBoth("VM End: %x\n",START_OF_VM+VM_SIZE-1);
-
-
- PrintBoth("Page struct size: %u bytes\n", sizeof(struct Page));
- PrintBoth("Page List Size: %u bytes\n", numPageListBytes);
-
-
- //pageListAddr = Round_Up_To_Page((ulong_t) &end);
- //pageListAddr = Round_Up_To_Page(HIGHMEM_START + KERNEL_HEAP_SIZE);
-
- // Note that this is now moved to be just above the kernel heap
- // see defs.h for layout
- pageListAddr=Round_Up_To_Page(KERNEL_PAGELIST);
-
- pageListEnd = Round_Up_To_Page(pageListAddr + numPageListBytes);
-
- g_pageList = (struct Page*) pageListAddr;
- // kernEnd = Round_Up_To_Page(pageListAddr + numPageListBytes);
- //
- // PAD - Note: I am changing this so that everything through the end of
- // the VM boot package (bioses/vmxassist) is off limits
- //kernEnd = Round_Up_To_Page((ulong_t) &end);
- kernEnd = Round_Up_To_Page(VM_BOOT_PACKAGE_END);
- s_numPages = numPages;
-
- PrintBoth("Pagelist addr: %p\n", g_pageList);
- PrintBoth("index: %p\n", &g_pageList[3]);
- PrintBoth("direct offset: %p\n", g_pageList + (sizeof(struct Page) * 2));
- PrintBoth("Kernel Size=%lx\n", (kernEnd - KERNEL_START_ADDR));
- PrintBoth("Kernel Start=%x\n", KERNEL_START_ADDR);
- PrintBoth("Kernel End=%lx\n", kernEnd);
- PrintBoth("VM Boot Package Start=%x\n", VM_BOOT_PACKAGE_START);
- PrintBoth("VM Boot Package End=%x\n", VM_BOOT_PACKAGE_END);
-
- /*
- * The initial kernel thread and its stack are placed
- * just beyond the ISA hole.
- */
- // This is no longer true
- // KASSERT(ISA_HOLE_END == KERN_THREAD_OBJ);
- // instead,
- //KASSERT(KERN_THREAD_OBJ==(START_OF_VM+VM_SIZE));
- //KASSERT(KERN_STACK == KERN_THREAD_OBJ + PAGE_SIZE);
-
- /*
- * Memory looks like this:
- * 0 - start: available (might want to preserve BIOS data area)
- * start - end: kernel
- * end - ISA_HOLE_START: available
- * ISA_HOLE_START - ISA_HOLE_END: used by hardware (and ROM BIOS?)
- * ISA_HOLE_END - HIGHMEM_START: used by initial kernel thread
- * HIGHMEM_START - end of memory: available
- * (the kernel heap is located at HIGHMEM_START; any unused memory
- * beyond that is added to the freelist)
- */
-
- // The VM region... 0 .. VM size is out of bounds
- KASSERT(START_OF_VM==0);
- Add_Page_Range(START_OF_VM, START_OF_VM+VM_SIZE, PAGE_VM);
- // The kernel is still in low memory at this point, in the VM region
- // Thus we will mark it as kernel use
- // Add_Page_Range(KERNEL_START_ADDR, kernEnd, PAGE_KERN);
-
-
- //Add_Page_Range(kernEnd, ISA_HOLE_START, PAGE_AVAIL);
- // ISA hole remains closed (no actual memory)
- // Add_Page_Range(ISA_HOLE_START, ISA_HOLE_END, PAGE_HW);
-
- //Add_Page_Range(ISA_HOLE_END, HIGHMEM_START, PAGE_ALLOCATED);
- // Add_Page_Range(HIGHMEM_START, HIGHMEM_START + KERNEL_HEAP_SIZE, PAGE_HEAP);
- //Add_Page_Range(HIGHMEM_START + KERNEL_HEAP_SIZE, endOfMem, PAGE_AVAIL);
- /* JRL: move page list after kernel heap */
-
- //Now, above the VM region...
-
- // Kernel thread object
- Add_Page_Range(KERNEL_THREAD_OBJECT,KERNEL_THREAD_OBJECT+KERNEL_THREAD_OBJECT_SIZE,PAGE_ALLOCATED);
- // Kernel stack
- Add_Page_Range(KERNEL_STACK,KERNEL_STACK+KERNEL_STACK_SIZE,PAGE_ALLOCATED);
- // Kernel heap
- Add_Page_Range(KERNEL_HEAP,KERNEL_HEAP+KERNEL_HEAP_SIZE,PAGE_HEAP);
- // Kernel page list
- Add_Page_Range(pageListAddr, pageListEnd, PAGE_KERN);
- // Free space
- Add_Page_Range(pageListEnd,Round_Down_To_Page(FINAL_KERNEL_START), PAGE_AVAIL);
- // The kernel
- Add_Page_Range(Round_Down_To_Page(FINAL_KERNEL_START),Round_Up_To_Page(FINAL_VMBOOTEND+1),PAGE_KERN);
- // The vmbootpackage
- // IDT (this should be one page)
- Add_Page_Range(IDT_LOCATION,TSS_LOCATION,PAGE_KERN);
- // TSS (this should be one page)
- Add_Page_Range(TSS_LOCATION,GDT_LOCATION, PAGE_KERN);
- // GDT (this should be one page)
- Add_Page_Range(GDT_LOCATION,TOP_OF_MEM, PAGE_KERN);
-
- /* Initialize the kernel heap */
- Init_Heap(KERNEL_HEAP, KERNEL_HEAP_SIZE);
-
- PrintBoth("%uKB memory detected, %u pages in freelist, %d bytes in kernel heap\n",
- bootInfo->memSizeKB, g_freePageCount, KERNEL_HEAP_SIZE);
-
- PrintBoth("Memory Layout:\n");
- PrintBoth("%x to %x - VM\n",START_OF_VM,START_OF_VM+VM_SIZE-1);
- PrintBoth("%x to %x - INITIAL THREAD\n",KERNEL_THREAD_OBJECT,KERNEL_THREAD_OBJECT+KERNEL_THREAD_OBJECT_SIZE-1);
- PrintBoth("%x to %x - KERNEL STACK\n",KERNEL_STACK,KERNEL_STACK+KERNEL_STACK_SIZE-1);
- PrintBoth("%x to %x - KERNEL HEAP\n",KERNEL_HEAP,KERNEL_HEAP+KERNEL_HEAP_SIZE-1);
- PrintBoth("%lx to %lx - PAGE LIST\n",pageListAddr,pageListEnd-1);
- PrintBoth("%lx to %x - FREE\n",pageListEnd,FINAL_KERNEL_START-1);
- PrintBoth("%x to %x - KERNEL CODE\n",FINAL_KERNEL_START,FINAL_KERNEL_END);
- PrintBoth("%x to %x - BIOS\n",FINAL_BIOS_START,FINAL_BIOS_END);
- PrintBoth("%x to %x - VGABIOS\n",FINAL_VGA_BIOS_START,FINAL_VGA_BIOS_END);
- PrintBoth("%x to %x - VMXASSIST\n",FINAL_VMXASSIST_START,FINAL_VMXASSIST_END);
- PrintBoth("%x to %x - BIOS (2nd copy)\n",FINAL_BIOS2_START,FINAL_BIOS2_END);
- PrintBoth("%x to %x - IDT\n",IDT_LOCATION,TSS_LOCATION-1);
- PrintBoth("%x to %x - TSS\n",TSS_LOCATION,GDT_LOCATION-1);
- PrintBoth("%x to %x - GDT\n",GDT_LOCATION,TOP_OF_MEM-1);
-
-}
-
-/*
- * Initialize the .bss section of the kernel executable image.
- */
-void Init_BSS(void)
-{
- extern char BSS_START, BSS_END;
-
- /* Fill .bss with zeroes */
- memset(&BSS_START, '\0', &BSS_END - &BSS_START);
- PrintBoth("BSS Inited, BSS_START=%x, BSS_END=%x\n",BSS_START,BSS_END);
-}
-
-/*
- * Allocate a page of physical memory.
- */
-void* Alloc_Page(void)
-{
- struct Page* page;
- void *result = 0;
-
- bool iflag = Begin_Int_Atomic();
-
- /* See if we have a free page */
- if (!Is_Page_List_Empty(&s_freeList)) {
- /* Remove the first page on the freelist. */
- page = Get_Front_Of_Page_List(&s_freeList);
- KASSERT((page->flags & PAGE_ALLOCATED) == 0);
- Remove_From_Front_Of_Page_List(&s_freeList);
-
- /* Mark page as having been allocated. */
- page->flags |= PAGE_ALLOCATED;
- g_freePageCount--;
- result = (void*) Get_Page_Address(page);
- }
-
- End_Int_Atomic(iflag);
-
- return result;
-}
-
-/*
- * Free a page of physical memory.
- */
-void Free_Page(void* pageAddr)
-{
- ulong_t addr = (ulong_t) pageAddr;
- struct Page* page;
- bool iflag;
-
- iflag = Begin_Int_Atomic();
-
- KASSERT(Is_Page_Multiple(addr));
-
- /* Get the Page object for this page */
- page = Get_Page(addr);
- KASSERT((page->flags & PAGE_ALLOCATED) != 0);
-
- /* Clear the allocation bit */
- page->flags &= ~(PAGE_ALLOCATED);
-
- /* Put the page back on the freelist */
- Add_To_Back_Of_Page_List(&s_freeList, page);
- g_freePageCount++;
-
- End_Int_Atomic(iflag);
-}