From 5654c02f365ee3f1548e316cee0d312559ea4e8f Mon Sep 17 00:00:00 2001
From: Max Wash <mbswash@gmail.com>
Date: Thu, 30 Apr 2026 18:59:46 +0100
Subject: [PATCH] x86_64: pmap: implement pmap_flush and pmap_remove_range

---
 arch/x86_64/pmap.c      | 12 ++++++++++++
 arch/x86_64/pmap_ctrl.S |  9 +++++++++
 2 files changed, 21 insertions(+)

diff --git a/arch/x86_64/pmap.c b/arch/x86_64/pmap.c
index 8eba547..d347336 100644
--- a/arch/x86_64/pmap.c
+++ b/arch/x86_64/pmap.c
@@ -321,6 +321,10 @@ static kern_status_t do_pmap_remove(
 	virt_addr_t pv,
 	enum page_size size)
 {
+	if (pmap == PMAP_INVALID) {
+		return KERN_OK;
+	}
+
 	unsigned int pml4t_index = BAD_INDEX, pdpt_index = BAD_INDEX,
 		     pd_index = BAD_INDEX, pt_index = BAD_INDEX;
 
@@ -622,5 +626,13 @@ kern_status_t pmap_remove(pmap_t pmap, virt_addr_t p)
 
 kern_status_t pmap_remove_range(pmap_t pmap, virt_addr_t p, size_t len)
 {
+	if (pmap == PMAP_INVALID) {
+		return KERN_OK;
+	}
+
+	for (size_t i = p; i < p + len; i += VM_PAGE_SIZE) {
+		pmap_remove(pmap, i);
+	}
+
 	return KERN_OK;
 }
diff --git a/arch/x86_64/pmap_ctrl.S b/arch/x86_64/pmap_ctrl.S
index 77f1b0e..9c3ac54 100644
--- a/arch/x86_64/pmap_ctrl.S
+++ b/arch/x86_64/pmap_ctrl.S
@@ -1,3 +1,11 @@
+	.global pmap_flush
+	.type pmap_flush, @function
+
+pmap_flush:
+	mov %cr3, %rax
+	mov %rax, %cr3
+	ret
+
 
 	.global pmap_switch
 	.type pmap_switch, @function
@@ -6,6 +14,7 @@ pmap_switch:
 	mov %rdi, %cr3
 	ret
 
+
 	.global gigabyte_pages
 	.type gigabyte_pages, @function