From 8a38d940cc06a2608a0bf491b334687774bd32a0 Mon Sep 17 00:00:00 2001
From: Max Wash <mbswash@gmail.com>
Date: Sun, 15 Mar 2026 22:22:25 +0000
Subject: [PATCH] vm: address-space: add function to translate virtual
 addresses to physical

---
 include/kernel/address-space.h |  9 +++++++-
 vm/address-space.c             | 40 ++++++++++++++++++++++++++++++++--
 2 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/include/kernel/address-space.h b/include/kernel/address-space.h
index d84c0fd..076201e 100644
--- a/include/kernel/address-space.h
+++ b/include/kernel/address-space.h
@@ -5,7 +5,8 @@
 #include <kernel/pmap.h>
 #include <kernel/vm.h>
 
-#define ADDRESS_SPACE_COPY_ALL ((size_t)-1)
+#define ADDRESS_SPACE_COPY_ALL ((size_t) - 1)
+#define ADDRESS_SPACE_F_
 
 struct address_space;
 struct vm_object;
@@ -158,6 +159,12 @@ extern kern_status_t address_space_memmove_v(
 	size_t bytes_to_move,
 	size_t *nr_bytes_moved);
 
+extern kern_status_t address_space_translate(
+	struct address_space *space,
+	virt_addr_t in,
+	phys_addr_t *out,
+	unsigned long *irq_flags);
+
 void address_space_dump(struct address_space *region);
 
 DEFINE_OBJECT_LOCK_FUNCTION(address_space, s_base)
diff --git a/vm/address-space.c b/vm/address-space.c
index f26421f..4dc16fc 100644
--- a/vm/address-space.c
+++ b/vm/address-space.c
@@ -110,9 +110,9 @@ static struct vm_area *get_entry(
 	enum get_entry_flags flags)
 {
 	/* `x` must be to the left of `y` */
-#define LEFT_DIFF(x, y)  ((y) ? ((y)->vma_base - (x)) : ((size_t)-1))
+#define LEFT_DIFF(x, y)  ((y) ? ((y)->vma_base - (x)) : ((size_t) - 1))
 	/* `x` must be to the right of `y` */
-#define RIGHT_DIFF(x, y) ((y) ? ((y)->vma_limit - (x)) : ((size_t)-1))
+#define RIGHT_DIFF(x, y) ((y) ? ((y)->vma_limit - (x)) : ((size_t) - 1))
 
 	struct btree_node *cur = region->s_mappings.b_root;
 	if (!cur) {
@@ -1413,6 +1413,42 @@ extern kern_status_t address_space_memmove_v(
 	return KERN_OK;
 }
 
+kern_status_t address_space_translate(
+	struct address_space *space,
+	virt_addr_t in,
+	phys_addr_t *out,
+	unsigned long *irq_flags)
+{
+	if (in >= VM_KERNEL_BASE) {
+		return vm_virt_to_phys((const void *)in);
+	}
+
+	struct vm_area *area = get_entry(space, in, GET_ENTRY_EXACT);
+	if (!area || !area->vma_object) {
+		return KERN_NO_ENTRY;
+	}
+
+	off_t offset = in - area->vma_base + area->vma_object_offset;
+	struct vm_object *vmo = area->vma_object;
+	vm_object_lock(vmo);
+	address_space_unlock(space);
+	struct vm_page *pg = vm_object_get_page(
+		vmo,
+		offset,
+		VMO_ALLOCATE_MISSING_PAGE | VMO_REQUEST_MISSING_PAGE,
+		irq_flags);
+	if (!pg) {
+		return KERN_NO_ENTRY;
+	}
+
+	phys_addr_t paddr = vm_page_get_paddr(pg);
+	paddr += (in & VM_PAGE_MASK);
+	vm_object_unlock(vmo);
+	address_space_lock(space);
+
+	return paddr;
+}
+
 #ifdef TRACE
 void address_space_dump(struct address_space *region)
 {