Import backup from 2004-07-17

kernel/mm/vmm.c

@@ -5,6 +5,7 @@
 // Modified: 07/13/04
 
 #include "hos_defines.h"
+#include "kernel.h"
 #include "mm/vmm.h"
 #include "asmfuncs.h"
 #include "mm/mm.h"
@@ -24,7 +25,13 @@ void	vmm_init()
 	int i;
 	for (i = 0; i < mb_info_block.mods_count; i++)	//page in the kernel modules
 		vmm_map_range((void*)mb_modules[i].mod_start, (void*)mb_modules[i].mod_end- 1, mb_modules[i].mod_start - VIRT_OFFSET);
-
+	vmm_heb_init(initialHEB);
+	vmm_addToQueue(VMM_HE_UNUSED, initialHEB[0]);
+	HeapEntry_t *wilderness = vmm_stripUnusedEntry();
+	wilderness->base = HEAP_START;
+	wilderness->length = HEAP_LENGTH;
+	wilderneww->next = 0;
+	vmm_addToQueue(VMM_HE_HOLE, wilderness);
 }
 
 
@@ -40,32 +47,33 @@ u32_t	vmm_map(void *virt)
 
 
 // This function maps a virtual address to a physical address using the page directory / page table
-void	vmm_map1(unsigned int virt, unsigned int physical)
+int	vmm_map1(unsigned int virt, unsigned int physical)
 {
 	unsigned int pde = virt >> 22;
 	unsigned int pte = (virt & 0x003FF000) >> 12;
 	unsigned int *pageTables = (unsigned int *)0xFFFFF000;	//this is the location of the page directory
-	if (!(pageTables[pde] & 0x01))		//the page directory entry does not exist, we must allocate a page for it
+	if (!(pageTables[pde] & 0x01))		//the page directory entry is not present, we must allocate a page table
 	{
-		u32_t newpagetable = mm_palloc();
+		u32_t newpagetable;
+		if (!(newpagetable = mm_palloc())
+			return 1;		//out of physical memory
 		pageTables[pde] = newpagetable | 0x03;
 		invlpg_(virt);		//in case it was cached, so we can fill page table safely
-		unsigned int *newpteptr = (unsigned int *)(0xFFC00000 | (pde << 12));	//points to first unsigned int of newly allocated page table
-		int a;
-		for (a = 0; a < 1024; a++)
-			*newpteptr++ = 0;
+		memsetd((void*)(0xFFC00000 | (pde << 12)), 0, 1024);	//zero out new page table
 	}
 	*(unsigned int *)(0xFFC00000 | (pde << 12) | (pte << 2)) = (physical & 0xFFFFF000) | 0x03;
 	invlpg_(virt);
+	return 0;
 }
 
 
 // This function maps a variable number of pages in a row
-void	vmm_mapn(unsigned int virt, unsigned int physical, unsigned int n)
+int	vmm_mapn(unsigned int virt, unsigned int physical, unsigned int n)
 {
 	while (n > 0)
 	{
-		vmm_map1(virt, physical);
+		if (vmm_map1(virt, physical))
+			return 1;	// error mapping page
 		virt += 4096;
 		physical += 4096;
 		n--;
@@ -96,10 +104,11 @@ void	vmm_unmapn(unsigned int virt, unsigned int n)
 int	vmm_map_range(void *virt_start, void *virt_end, u32_t phys_start)
 {
 	if (virt_end < virt_start)
-		return 1;	//invalid region
+		return 1;	// invalid region
 	while (virt_start < virt_end)
 	{
-		vmm_map1((u32_t)virt_start, phys_start);
+		if (vmm_map1((u32_t)virt_start, phys_start))
+			return 2;	// out of memory
 		virt_start += 4096;
 		phys_start += 4096;
 	}
@@ -107,6 +116,20 @@ int	vmm_map_range(void *virt_start, void *virt_end, u32_t phys_start)
 }
 
 
+void *kmalloc(u32_t size)
+{
+	k_enter_critical();
+	k_leave_critical();
+}
+
+
+void *vmm_palloc()
+{
+	k_enter_critical();
+	k_leave_critical();
+}
+
+
 // This function allocates and zeros memory for the given number of objects,
 //  given the size of each object
 /*
@@ -158,7 +181,6 @@ int vmm_countHeapEntries(HeapEntry_t *he)
 }
 
 
-
 // This function follows a chain of HeapEntry objects and returns a pointer to the last one
 HeapEntry_t *vmm_followChain(HeapEntry_t *he)
 {
@@ -169,18 +191,24 @@ HeapEntry_t *vmm_followChain(HeapEntry_t *he)
 
 
 // This function breaks an unused chunk from its queue and returns a pointer to it
-HeapEntry_t *vmm_getUnusedChunk()
+HeapEntry_t *vmm_getUnusedEntry()
 {
 	if (heapEntryQueues[VMM_HE_UNUSED].count < 5)
 	{
-		heapEntryQueues[VMM_HE_UNUSED].count += 256;//not good idea
-		HeapEntryBlock_t *newHEB = vmm_palloc();   //INFINITE LOOP?
-		vmm_mcb_init(newHEB);
+		HeapEntry_t *wilderness = vmm_followChain(
+		HeapEntryBlock_t *newHEB;
+		vmm_heb_init(newHEB);
 		vmm_addToQueue(VMM_HE_UNUSED, newHEB);
-		heapEntryQueues[VMM_HE_UNUSED].count -= 256;
 	}
+	return vmm_stripUnusedEntry();
+}
+
+
+// Return pointer to an unused HeapEntry object, ASSUMES THERE IS ONE PRESENT IN QUEUE
+HeapEntry_t *vmm_stripUnusedEntry()
+{
 	HeapEntry_t *he = heapEntryQueues[VMM_HE_UNUSED].start;
-	heapEntryQueues[VMM_HE_UNUSED].start = he->link;
+	heapEntryQueues[VMM_HE_UNUSED].start = he->next;
 	heapEntryQueues[VMM_HE_UNUSED].count--;
 	return he;
 }

kernel/mm/vmm.h

@@ -27,7 +27,6 @@ typedef struct {
 	u32_t	padding;
 } __attribute__((packed)) HeapEntry_t;
 
-
 typedef struct {
 	HeapEntry_t	entry[256];	//256 HeapEntry objects = 4kb (1 page)
 } __attribute__((packed)) HeapEntryBlock_t;
@@ -37,10 +36,11 @@ typedef struct {
 	HeapEntry_t *start;
 } HeapEntryQueue_t;
 
+
 void	vmm_init();
 u32_t	vmm_map(void *virt);
-void	vmm_map1(unsigned int virt, unsigned int physical);
-void	vmm_mapn(unsigned int virt, unsigned int physical, unsigned int n);
+int	vmm_map1(unsigned int virt, unsigned int physical);
+int	vmm_mapn(unsigned int virt, unsigned int physical, unsigned int n);
 void	vmm_unmap1(unsigned int virt);
 void	vmm_unmapn(unsigned int virt, unsigned int n);
 int	vmm_map_range(void *virt_start, void *virt_end, u32_t phys_start);