From bd354fed8ce698302348dd8d53ee9a590d761db9 Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@mirocom.org>
Date: Sun, 26 Apr 2026 00:21:19 -0400
Subject: [PATCH] sp1/amd64: mmu: Add function to unmap regions

Signed-off-by: Ian Moffett <ian@mirocom.org>
---
 usr/src/sp1/amd64/cpu/cpu_mmu.c | 21 +++++++++++++++++++++
 usr/src/sp1/head/mu/mmu.h       | 13 +++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/usr/src/sp1/amd64/cpu/cpu_mmu.c b/usr/src/sp1/amd64/cpu/cpu_mmu.c
index 79d5e54..6ce54c4 100644
--- a/usr/src/sp1/amd64/cpu/cpu_mmu.c
+++ b/usr/src/sp1/amd64/cpu/cpu_mmu.c
@@ -267,3 +267,24 @@ mu_mmu_map(struct mmu_vfr *vfr, uintptr_t vma, uintptr_t pma,
     md_tlb_flush(vma);
     return STATUS_SUCCESS;
 }
+
+status_t
+mu_mmu_unmap(struct mmu_vfr *vfr, uintptr_t vma, pagesize_t ps)
+{
+    uintptr_t *tbl;
+    size_t index;
+
+    if (vfr == NULL) {
+        return STATUS_INVALID_PARAM;
+    }
+
+    tbl = mmu_extract_level(vfr, vma, PAGELVL_PML1, false);
+    if (tbl == NULL) {
+        return STATUS_NOT_FOUND;
+    }
+
+    index = mmu_extract_index(vma, PAGELVL_PML1);
+    tbl[index] = 0;
+    md_tlb_flush(vma);
+    return STATUS_SUCCESS;
+}
diff --git a/usr/src/sp1/head/mu/mmu.h b/usr/src/sp1/head/mu/mmu.h
index bad2a49..4c07945 100644
--- a/usr/src/sp1/head/mu/mmu.h
+++ b/usr/src/sp1/head/mu/mmu.h
@@ -62,6 +62,19 @@ status_t mu_mmu_map(
     pagesize_t ps
 );
 
+/*
+ * Destroy a virtual memory mapping in the virtual
+ * fuck region
+ *
+ * @vfr: Virtual fuck region to unmap within
+ * @vma: Virtual memory address to unmap
+ * @ps:  Pagesize of address to unmap
+ */
+status_t mu_mmu_unmap(
+    struct mmu_vfr *vfr, uintptr_t vma,
+    pagesize_t ps
+);
+
 /*
  * Fork a VFR and clear out the lower half
  *