Some work in progress of the MTRR support. Shouldn't do any harm yet :-)

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@15525 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/arch/vm.h

@@ -24,7 +24,7 @@ void arch_vm_aspace_swap(vm_address_space *aspace);
 bool arch_vm_supports_protection(uint32 protection);
 void arch_vm_init_area(vm_area *area);
 
-status_t arch_vm_set_memory_type(vm_area *area, uint32 type);
+status_t arch_vm_set_memory_type(vm_area *area, addr_t physicalBase, uint32 type);
 void arch_vm_unset_memory_type(vm_area *area);
 
 #ifdef __cplusplus

headers/private/kernel/arch/x86/arch_cpu.h

@@ -14,14 +14,23 @@
 
 
 // MSR registers (possibly Intel specific)
-#define IA32_MSR_APIC_BASE	0x1b
+#define IA32_MSR_APIC_BASE				0x1b
+
+#define IA32_MSR_MTRR_CAPABILITIES		0xfe
+#define IA32_MSR_MTRR_DEFAULT_TYPE		0x2ff
+#define IA32_MSR_MTRR_PHYSICAL_BASE_0	0x200
+#define IA32_MSR_MTRR_PHYSICAL_MASK_0	0x201
 
 
 typedef struct x86_cpu_module_info {
 	module_info	info;
 	uint32		(*count_mtrrs)(void);
-	status_t	(*set_mtrr)(uint32 index, addr_t base, addr_t length, uint32 type);
-	status_t	(*unset_mtrr)(uint32 index);
+	status_t	(*enable_mtrrs)(void);
+	void		(*disable_mtrrs)(void);
+
+	void		(*set_mtrr)(uint32 index, addr_t base, addr_t length, uint32 type);
+	status_t	(*get_mtrr)(uint32 index, addr_t *_base, addr_t *_length,
+					uint32 *_type);
 } x86_cpu_module_info;
 
 
@@ -91,8 +100,10 @@ uint64 x86_read_msr(uint32 registerNumber);
 void x86_write_msr(uint32 registerNumber, uint64 value);
 void x86_set_task_gate(int32 n, int32 segment);
 uint32 x86_count_mtrrs(void);
+status_t x86_enable_mtrrs(void);
+status_t x86_disable_mtrrs(void);
 status_t x86_set_mtrr(uint32 index, addr_t base, addr_t length, uint32 type);
-status_t x86_unset_mtrr(uint32 index);
+status_t x86_get_mtrr(uint32 index, addr_t *_base, addr_t *_length, uint32 *_type);
 struct tss *x86_get_main_tss(void);
 
 #define read_ebp(value) \

headers/private/kernel/debug.h

@@ -30,6 +30,7 @@ extern "C" {
 
 extern status_t debug_init(struct kernel_args *args);
 extern status_t	debug_init_post_vm(struct kernel_args *args);
+extern status_t	debug_init_post_modules(struct kernel_args *args);
 extern void debug_early_boot_message(const char *string);
 extern void debug_puts(const char *s);
 extern bool debug_debugger_running(void);

headers/private/kernel/frame_buffer_console.h

@@ -28,6 +28,7 @@ extern "C" {
 
 bool frame_buffer_console_available(void);
 status_t frame_buffer_console_init(struct kernel_args *args);
+status_t frame_buffer_console_init_post_modules(struct kernel_args *args);
 
 status_t _user_frame_buffer_update(addr_t baseAddress, int32 width, int32 height,
 			int32 depth, int32 bytesPerRow);

headers/private/kernel/vm.h

@@ -67,6 +67,8 @@ area_id vm_clone_area(aspace_id aid, const char *name, void **address,
 status_t vm_delete_area(aspace_id aid, area_id id);
 status_t vm_create_vnode_cache(void *vnode, vm_cache_ref **_cacheRef);
 
+status_t vm_set_area_memory_type(area_id id, addr_t physicalBase, uint32 type);
+
 status_t vm_get_page_mapping(aspace_id aid, addr_t vaddr, addr_t *paddr);
 status_t vm_get_physical_page(addr_t paddr, addr_t *vaddr, int flags);
 status_t vm_put_physical_page(addr_t vaddr);

src/add-ons/kernel/cpu/x86/Jamfile

@@ -5,6 +5,6 @@ UsePrivateHeaders kernel ;
 KernelAddon generic_x86 : kernel cpu :
 	generic_x86.cpp
 	intel.cpp
-	amd.cpp
-	via.cpp
+#	amd.cpp
+#	via.cpp
 	;

src/add-ons/kernel/cpu/x86/generic_x86.cpp

@@ -12,9 +12,9 @@
 #include "via.h"
 
 
-module_info *gModules[] = {
+module_info *modules[] = {
 	(module_info *)&gIntelModule,
-	(module_info *)&gAMDModule,
-	(module_info *)&gVIAModule,
+//	(module_info *)&gAMDModule,
+//	(module_info *)&gVIAModule,
 	NULL
 };

src/add-ons/kernel/cpu/x86/intel.cpp

@@ -9,24 +9,95 @@
 
 #include "intel.h"
 
+#include <KernelExport.h>
+#include <OS.h>
+#include <arch_cpu.h>
+
+
+#define IA32_MTRR_FEATURE				(1UL << 12)
+#define IA32_MTRR_ENABLE				(1UL << 11)
+#define IA32_MTRR_ENABLE_FIXED			(1UL << 10)
+#define IA32_MTRR_VALID_RANGE			(1UL << 11)
+
+struct mtrr_capabilities {
+	mtrr_capabilities(uint64 value) { *(uint64 *)this = value; }
+
+	uint64	variable_ranges : 8;
+	uint64	supports_fixed : 1;
+	uint64	_reserved0 : 1;
+	uint64	supports_write_combined : 1;
+	uint64	_reserved1 : 53;
+};
+
 
 static uint32
 intel_count_mtrrs(void)
 {
-	return 0;
+	cpuid_info cpuInfo;
+	if (get_cpuid(&cpuInfo, 1, 0) != B_OK
+		|| (cpuInfo.eax_1.features & IA32_MTRR_FEATURE) == 0)
+		return 0;
+
+	mtrr_capabilities capabilities(x86_read_msr(IA32_MSR_MTRR_CAPABILITIES));
+	return capabilities.variable_ranges;
 }
 
 
 static status_t
-intel_set_mtrr(uint32 index, addr_t base, addr_t length, uint32 type)
+intel_enable_mtrrs(void)
 {
+	cpuid_info cpuInfo;
+	if (get_cpuid(&cpuInfo, 1, 0) != B_OK
+		|| (cpuInfo.eax_1.features & IA32_MTRR_FEATURE) == 0)
+		return B_NOT_SUPPORTED;
+
+	x86_write_msr(IA32_MSR_MTRR_DEFAULT_TYPE,
+		x86_read_msr(IA32_MSR_MTRR_DEFAULT_TYPE) | IA32_MTRR_ENABLE);
+
 	return B_OK;
 }
 
 
-static status_t
-intel_unset_mtrr(uint32 index)
+static void
+intel_disable_mtrrs(void)
 {
+	x86_write_msr(IA32_MSR_MTRR_DEFAULT_TYPE,
+		x86_read_msr(IA32_MSR_MTRR_DEFAULT_TYPE) & ~IA32_MTRR_ENABLE);
+}
+
+
+static void
+intel_set_mtrr(uint32 index, addr_t base, addr_t length, uint32 type)
+{
+	if (base != 0 && length != 0) {
+		// enable MTRR
+
+		x86_write_msr(IA32_MSR_MTRR_PHYSICAL_BASE_0 + index,
+			(base & ~(B_PAGE_SIZE - 1)) | type);
+		x86_write_msr(IA32_MSR_MTRR_PHYSICAL_MASK_0 + index,
+			(length & ~(B_PAGE_SIZE - 1)) | IA32_MTRR_VALID_RANGE);
+	} else {
+		// disable MTRR
+
+		x86_write_msr(IA32_MSR_MTRR_PHYSICAL_MASK_0 + index, 0);
+		x86_write_msr(IA32_MSR_MTRR_PHYSICAL_BASE_0 + index, 0);
+	}
+}
+
+
+static status_t
+intel_get_mtrr(uint32 index, addr_t *_base, addr_t *_length, uint32 *_type)
+{
+	uint64 base = x86_read_msr(IA32_MSR_MTRR_PHYSICAL_BASE_0 + index);
+	uint64 mask = x86_read_msr(IA32_MSR_MTRR_PHYSICAL_MASK_0 + index);
+
+	if ((mask & IA32_MTRR_VALID_RANGE) == 0)
+		return B_ERROR;
+
+	*_base = base & ~(B_PAGE_SIZE - 1);
+	*_length = mask & ~(B_PAGE_SIZE - 1);
+	*_type = base & 0xff;
+
 	return B_OK;
 }
 
@@ -38,10 +109,28 @@ intel_init(void)
 	if (get_system_info(&info) != B_OK)
 		return B_ERROR;
 
-	if ((info.cpu_type & B_CPU_x86_VENDOR_MASK) != B_CPU_INTEL_x86)
+	if ((info.cpu_type & B_CPU_x86_VENDOR_MASK) != B_CPU_INTEL_x86
+		|| (info.cpu_type & B_CPU_x86_VENDOR_MASK) != B_CPU_AMD_x86)
 		return B_ERROR;
 
-	return B_OK;
+	if (x86_read_msr(IA32_MSR_MTRR_DEFAULT_TYPE) & IA32_MTRR_ENABLE)
+		dprintf("MTRR enabled\n");
+	else
+		dprintf("MTRR disabled\n");
+
+	for (uint32 i = 0; i < intel_count_mtrrs(); i++) {
+		addr_t base;
+		addr_t length;
+		uint32 type;
+		if (intel_get_mtrr(i, &base, &length, &type) == B_OK)
+			dprintf("  %ld: %p, %p, %ld\n", i, (void *)base, (void *)length, type);
+		else
+			dprintf("  %ld: empty\n", i);
+	}
+
+// don't open it just now	
+	return B_ERROR;
+//	return B_OK;
 }
 
 
@@ -74,6 +163,9 @@ x86_cpu_module_info gIntelModule = {
 	},
 
 	intel_count_mtrrs,
+	intel_enable_mtrrs,
+	intel_disable_mtrrs,
+
 	intel_set_mtrr,
-	intel_unset_mtrr,
+	intel_get_mtrr,
 };

src/system/kernel/arch/ppc/arch_vm.cpp

@@ -126,7 +126,7 @@ arch_vm_unset_memory_type(vm_area *area)
 
 
 status_t
-arch_vm_set_memory_type(vm_area *area, uint32 type)
+arch_vm_set_memory_type(vm_area *area, addr_t physicalBase, uint32 type)
 {
 	if (type == 0)
 		return B_OK;

src/system/kernel/arch/x86/arch_cpu.c

@@ -103,22 +103,44 @@ x86_count_mtrrs(void)
 
 
 status_t
-x86_set_mtrr(uint32 index, addr_t base, addr_t length, uint32 type)
+x86_enable_mtrrs(void)
 {
 	if (load_cpu_module() == NULL)
-		return B_UNSUPPORTED;
+		return B_NOT_SUPPORTED;
 
-	return sCpuModule->set_mtrr(index, base, length, type);
+	return sCpuModule->enable_mtrrs();
 }
 
 
 status_t
-x86_unset_mtrr(uint32 index)
+x86_disable_mtrrs(void)
 {
 	if (load_cpu_module() == NULL)
-		return B_UNSUPPORTED;
+		return B_NOT_SUPPORTED;
 
-	return sCpuModule->unset_mtrr(index);
+	sCpuModule->disable_mtrrs();
+	return B_OK;
+}
+
+
+status_t
+x86_set_mtrr(uint32 index, addr_t base, addr_t length, uint32 type)
+{
+	if (load_cpu_module() == NULL)
+		return B_NOT_SUPPORTED;
+
+	sCpuModule->set_mtrr(index, base, length, type);
+	return B_OK;
+}
+
+
+status_t
+x86_get_mtrr(uint32 index, addr_t *_base, addr_t *_length, uint32 *_type)
+{
+	if (load_cpu_module() == NULL)
+		return B_NOT_SUPPORTED;
+
+	return sCpuModule->get_mtrr(index, _base, _length, _type);
 }
 
 

src/system/kernel/arch/x86/arch_vm.c

@@ -30,26 +30,27 @@
 #endif
 
 
-static uint32 *sMTRRBitmap;
+struct set_mtrr_parameter {
+	int32	index;
+	addr_t	base;
+	addr_t	length;
+	uint8	type;
+};
+
+
+static uint32 sMTRRBitmap;
 static int32 sMTRRCount;
 static spinlock sMTRRLock;
 
 
 static status_t
-init_mtrr_bitmap(void)
+init_mtrr(void)
 {
-	if (sMTRRBitmap != NULL)
-		return B_OK;
-
 	sMTRRCount = x86_count_mtrrs();
 	if (sMTRRCount == 0)
-		return B_UNSUPPORTED;
+		return B_NOT_SUPPORTED;
 
-	sMTRRBitmap = malloc(sMTRRCount / 8);
-	if (sMTRRBitmap == NULL)
-		return B_NO_MEMORY;
-
-	memset(sMTRRBitmap, 0, sMTRRCount / 8);
+	sMTRRBitmap = 0;
 	return B_OK;
 }
 
@@ -57,28 +58,22 @@ init_mtrr_bitmap(void)
 static int32
 allocate_mtrr(void)
 {
-	int32 count = sMTRRCount / 32;
-	int32 i, j;
+	int32 index;
 
 	cpu_status state = disable_interrupts();
 	acquire_spinlock(&sMTRRLock);
 
-	for (i = 0; i < count; i++) {
-		if (sMTRRBitmap[i] == 0xffffffff)
+	// find free bit
+
+	for (index = 0; index < 32; index++) {
+		if (sMTRRBitmap & (1UL << index))
 			continue;
 
-		// find free bit
+		sMTRRBitmap |= 1UL << index;
 
-		for (j = 0; j < 32; j++) {
-			if (sMTRRBitmap[i] & (1UL << j))
-				continue;
-
-			sMTRRBitmap[i] |= 1UL << j;
-
-			release_spinlock(&sMTRRLock);
-			restore_interrupts(state);
-			return i * 32 + j;
-		}
+		release_spinlock(&sMTRRLock);
+		restore_interrupts(state);
+		return index;
 	}
 
 	release_spinlock(&sMTRRLock);
@@ -91,19 +86,38 @@ allocate_mtrr(void)
 static void
 free_mtrr(int32 index)
 {
-	int32 i = index / 32;
-	int32 j = index - i * 32;
-
 	cpu_status state = disable_interrupts();
 	acquire_spinlock(&sMTRRLock);
 
-	sMTRRBitmap[i] &= ~(1UL << j);
+	sMTRRBitmap &= ~(1UL << index);
 
 	release_spinlock(&sMTRRLock);
 	restore_interrupts(state);
 }
 
 
+static void
+unset_mtrr(void *_index, int cpu)
+{
+	int32 index = (int32)_index;
+
+	x86_set_mtrr(index, 0, 0, 0);
+}
+
+
+static void
+set_mtrr(void *_parameter, int cpu)
+{
+	struct set_mtrr_parameter *parameter = (struct set_mtrr_parameter *)_parameter;
+
+	x86_set_mtrr(parameter->index, parameter->base, parameter->length,
+		parameter->type);
+}
+
+
+//	#pragma mark -
+
+
 status_t
 arch_vm_init(kernel_args *args)
 {
@@ -182,58 +196,58 @@ arch_vm_unset_memory_type(vm_area *area)
 	if (area->memory_type.type == 0)
 		return;
 
-	x86_unset_mtrr(area->memory_type.index);
+	call_all_cpus(&unset_mtrr, (void *)(int32)area->memory_type.index);
 	free_mtrr(area->memory_type.index);
 }
 
 
 status_t
-arch_vm_set_memory_type(vm_area *area, uint32 type)
+arch_vm_set_memory_type(vm_area *area, addr_t physicalBase, uint32 type)
 {
-	status_t status;
-	int32 index;
+	struct set_mtrr_parameter parameter;
 
 	if (type == 0)
 		return B_OK;
 
 	switch (type) {
 		case B_MTR_UC:	// uncacheable
-			type = 0;
+			parameter.type = 0;
 			break;
 		case B_MTR_WC:	// write combining
-			type = 1;
+			parameter.type = 1;
 			break;
 		case B_MTR_WT:	// write through
-			type = 4;
+			parameter.type = 4;
 			break;
 		case B_MTR_WP:	// write protected
-			type = 5;
+			parameter.type = 5;
 			break;
 		case B_MTR_WB:	// write back
-			type = 6;
+			parameter.type = 6;
 			break;
 
 		default:
 			return B_BAD_VALUE;
 	}
 
-	if (sMTRRBitmap == NULL) {
-		status = init_mtrr_bitmap();
+	if (sMTRRCount == 0) {
+		status_t status = init_mtrr();
 		if (status < B_OK)
 			return status;
 	}
 
-	index = allocate_mtrr();
-	if (index < 0)
+	parameter.index = allocate_mtrr();
+	if (parameter.index < 0)
 		return B_ERROR;
 
-	status = x86_set_mtrr(index, area->base, area->size, type);
-	if (status != B_OK) {
-		area->memory_type.type = (uint16)type;
-		area->memory_type.index = (uint16)index;
-	} else
-		free_mtrr(index);
+	parameter.base = physicalBase;
+	parameter.length = area->size;
 
-	dprintf("memory type: %u, index: %ld\n", area->memory_type.type, index);
-	return status;
+	call_all_cpus(&set_mtrr, &parameter);
+
+	area->memory_type.type = parameter.type;
+	area->memory_type.index = (uint16)parameter.index;
+
+	dprintf("memory type: %u, index: %ld\n", area->memory_type.type, parameter.index);
+	return B_OK;
 }

src/system/kernel/debug/debug.c

@@ -439,6 +439,13 @@ debug_init_post_vm(kernel_args *args)
 }
 
 
+status_t
+debug_init_post_modules(struct kernel_args *args)
+{
+	return frame_buffer_console_init_post_modules(args);
+}
+
+
 //	#pragma mark - public API
 
 

src/system/kernel/debug/frame_buffer_console.cpp

@@ -7,6 +7,7 @@
 #include <kernel.h>
 #include <lock.h>
 #include <boot_item.h>
+#include <vm.h>
 #include <fs/devfs.h>
 #include <boot/kernel_args.h>
 
@@ -110,7 +111,7 @@ render_glyph(int32 x, int32 y, uint8 glyph, uint8 attr)
 			+ x * CHAR_WIDTH * sConsole.bytes_per_pixel);
 		uint8 *color = get_palette_entry(foreground_color(attr));
 		uint8 *backgroundColor = get_palette_entry(background_color(attr));
-	
+
 		for (y = 0; y < CHAR_HEIGHT; y++) {
 			uint8 bits = FONT[CHAR_HEIGHT * glyph + y];
 			for (x = 0; x < CHAR_WIDTH; x++) {
@@ -122,7 +123,7 @@ render_glyph(int32 x, int32 y, uint8 glyph, uint8 attr)
 				}
 				bits >>= 1;
 			}
-	
+
 			base += sConsole.bytes_per_row;
 		}
 	} else {
@@ -426,6 +427,19 @@ frame_buffer_console_init(kernel_args *args)
 }
 
 
+status_t
+frame_buffer_console_init_post_modules(kernel_args *args)
+{
+	if (sConsole.frame_buffer == NULL)
+		return B_OK;
+
+	// try to set frame buffer memory to write combined
+
+	return vm_set_area_memory_type(sConsole.area,
+		args->frame_buffer.physical_buffer.start, B_MTR_WC);
+}
+
+
 //	#pragma mark -
 
 

src/system/kernel/int.c

@@ -225,6 +225,22 @@ int_io_interrupt_handler(int vector)
 	int status = B_UNHANDLED_INTERRUPT;
 	struct io_handler *io;
 
+#if 0
+{
+	static int low[2];
+	static int high[2];
+	static int counter;
+	int32 cpu = smp_get_current_cpu();
+
+	if (vector > 0xf0 - 32)
+		high[cpu]++;
+	else
+		low[cpu]++;
+	dprintf("got vector %d at CPU %ld\n", vector, cpu);
+	//if ((counter++ % 10) == 0)
+		dprintf("ints: %d/%d (high: %d/%d)\n", low[0], low[1], high[0], high[1]);
+}
+#endif
 	acquire_spinlock(&io_vectors[vector].vector_lock);
 
 	// The list can be empty at this place

src/system/kernel/main.c

@@ -215,27 +215,8 @@ main2(void *unused)
 	TRACE(("Mount boot file system\n"));
 	vfs_mount_boot_file_system(&sKernelArgs);
 
-	//module_test();
-#if 0
-		// XXX remove
-		vfs_test();
-#endif
-#if 0
-		// XXX remove
-		thread_test();
-#endif
-#if 0
-		vm_test();
-#endif
-#if 0
-	panic("debugger_test\n");
-#endif
-#if 0
-	cbuf_test();
-#endif
-#if 0
-	port_test();
-#endif
+	debug_init_post_modules(&sKernelArgs);
+
 	// start the init process
 	{
 		const char *shellArgs[] = {"/bin/sh", "/boot/beos/system/boot/Bootscript", NULL};

src/system/kernel/vm/vm.cpp

@@ -935,20 +935,22 @@ vm_create_anonymous_area(aspace_id aid, const char *name, void **address,
 
 
 area_id
-vm_map_physical_memory(aspace_id aid, const char *name, void **_address,
-	uint32 addressSpec, addr_t size, uint32 protection, addr_t phys_addr)
+vm_map_physical_memory(aspace_id areaID, const char *name, void **_address,
+	uint32 addressSpec, addr_t size, uint32 protection,
+	addr_t physicalAddress)
 {
 	vm_area *area;
 	vm_cache *cache;
-	vm_cache_ref *cache_ref;
+	vm_cache_ref *cacheRef;
 	vm_store *store;
-	addr_t map_offset;
+	addr_t mapOffset;
 	status_t status;
-	vm_address_space *aspace = vm_get_aspace_by_id(aid);
+	vm_address_space *aspace = vm_get_aspace_by_id(areaID);
 
 	TRACE(("vm_map_physical_memory(aspace = %ld, \"%s\", virtual = %p, spec = %ld,"
 		" size = %lu, protection = %ld, phys = %p)\n",
-		aid, name, _address, addressSpec, size, protection, (void *)phys_addr));
+		areaID, name, _address, addressSpec, size, protection,
+		(void *)physicalAddress));
 
 	if (!arch_vm_supports_protection(protection))
 		return B_NOT_SUPPORTED;
@@ -958,33 +960,36 @@ vm_map_physical_memory(aspace_id aid, const char *name, void **_address,
 
 	// if the physical address is somewhat inside a page,
 	// move the actual area down to align on a page boundary
-	map_offset = phys_addr % B_PAGE_SIZE;
-	size += map_offset;
-	phys_addr -= map_offset;
+	mapOffset = physicalAddress % B_PAGE_SIZE;
+	size += mapOffset;
+	physicalAddress -= mapOffset;
 
 	size = PAGE_ALIGN(size);
 
 	// create an device store object
-	store = vm_store_create_device(phys_addr);
+	// TODO: panic???
+	store = vm_store_create_device(physicalAddress);
 	if (store == NULL)
 		panic("vm_map_physical_memory: vm_store_create_device returned NULL");
 	cache = vm_cache_create(store);
 	if (cache == NULL)
 		panic("vm_map_physical_memory: vm_cache_create returned NULL");
-	cache_ref = vm_cache_ref_create(cache);
-	if (cache_ref == NULL)
+	cacheRef = vm_cache_ref_create(cache);
+	if (cacheRef == NULL)
 		panic("vm_map_physical_memory: vm_cache_ref_create returned NULL");
+
 	// tell the page scanner to skip over this area, it's pages are special
 	cache->scan_skip = 1;
 
-	vm_cache_acquire_ref(cache_ref, true);
+	vm_cache_acquire_ref(cacheRef, true);
 	status = map_backing_store(aspace, store, _address, 0, size,
 		addressSpec & ~B_MTR_MASK, 0, protection, REGION_NO_PRIVATE_MAP, &area, name);
-	vm_cache_release_ref(cache_ref);
+	vm_cache_release_ref(cacheRef);
 
 	if (status >= B_OK && (addressSpec & B_MTR_MASK) != 0) {
 		// set requested memory type
-		status = arch_vm_set_memory_type(area, addressSpec & B_MTR_MASK);
+		status = arch_vm_set_memory_type(area, physicalAddress,
+			addressSpec & B_MTR_MASK);
 		if (status < B_OK)
 			vm_put_area(area);
 	}
@@ -1003,7 +1008,7 @@ vm_map_physical_memory(aspace_id aid, const char *name, void **_address,
 
 	// modify the pointer returned to be offset back into the new area
 	// the same way the physical address in was offset
-	*_address = (void *)((addr_t)*_address + map_offset);
+	*_address = (void *)((addr_t)*_address + mapOffset);
 
 	return area->id;
 }
@@ -2750,6 +2755,25 @@ vm_try_reserve_memory(size_t amount)
 }
 
 
+status_t
+vm_set_area_memory_type(area_id id, addr_t physicalBase, uint32 type)
+{
+	vm_area *area = vm_get_area(id);
+	if (area == NULL)
+		return B_BAD_VALUE;
+
+	status_t status = arch_vm_set_memory_type(area, physicalBase, type);
+	if (status < B_OK)
+		goto out;
+
+	arch_cpu_invalidate_TLB_range(area->base, area->size);
+
+out:
+	vm_put_area(area);
+	return status;
+}
+
+
 /**	This function enforces some protection properties:
  *	 - if B_WRITE_AREA is set, B_WRITE_KERNEL_AREA is set as well
  *	 - if only B_READ_AREA has been set, B_KERNEL_READ_AREA is also set