From d63c88259f50f60fa7b1443ff7cf1a673e7f08b7 Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@mirocom.org>
Date: Wed, 22 Apr 2026 23:56:01 -0400
Subject: [PATCH] sp1: mm: Add MI virtual memory management

Signed-off-by: Ian Moffett <ian@mirocom.org>
---
 usr/src/sp1/common/mm/vm_map.c | 67 ++++++++++++++++++++++++++++++++++
 usr/src/sp1/head/mm/vm.h       | 25 +++++++++++++
 2 files changed, 92 insertions(+)
 create mode 100644 usr/src/sp1/common/mm/vm_map.c

diff --git a/usr/src/sp1/common/mm/vm_map.c b/usr/src/sp1/common/mm/vm_map.c
new file mode 100644
index 0000000..20485d8
--- /dev/null
+++ b/usr/src/sp1/common/mm/vm_map.c
@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2026, Mirocom Laboratories
+ * All rights reserved.
+ *
+ * The following sources are CONFIDENTIAL and PROPRIETARY
+ * property of Mirocom Laboratories. Unauthorized copying,
+ * use, distribution or modification of this file, in whole
+ * and in part, is strictly prohibited without the prior written
+ * consent from Mirocom Laboratories.
+ */
+
+#include <sys/units.h>
+#include <sys/param.h>
+#include <lib/printf.h>
+#include <mu/mmu.h>
+#include <mu/param.h>
+#include <mm/vm.h>
+
+#define pr_trace(fmt, ...) \
+    printf("vm_map: " fmt, ##__VA_ARGS__)
+
+/* Used to safely convert pagesize constants */
+#define GRAN(ps)        \
+    ((ps) <= PAGESIZE_1G)   \
+        ? pstab[(ps)]       \
+        : pstab[PAGESIZE_4K]
+
+/* Pagesize constant to length table */
+static size_t pstab[] = {
+    [PAGESIZE_4K] = 0x1000,
+    [PAGESIZE_2M] = UNIT_MIB * 2,
+    [PAGESIZE_1G] = UNIT_GIB
+};
+
+status_t
+mm_vm_map(struct mmu_vfr *vfr, struct vm_map *mapping, int prot)
+{
+    size_t len, gran;
+    uintptr_t vma, pma;
+    status_t status;
+
+    if (vfr == NULL || mapping == NULL) {
+        return STATUS_INVALID_PARAM;
+    }
+
+    gran = GRAN(mapping->ps);
+    len = mapping->length;
+
+    vma = ALIGN_DOWN(mapping->vma_base, gran);
+    pma = ALIGN_DOWN(mapping->pma_base, gran);
+    len = ALIGN_UP(len + (len & (gran - 1)), gran);
+
+    for (size_t i = 0; i < len; i += gran) {
+        status = mu_mmu_map(vfr, vma + i, pma + i, prot, mapping->ps);
+
+        /*
+         * TODO: We need to clean up here instead of leaving a big hole
+         *       when this fails.
+         */
+        if (status != STATUS_SUCCESS) {
+            pr_trace("mapping failed, leaked %d bytes\n", len);
+            return status;
+        }
+    }
+
+    return STATUS_SUCCESS;
+}
diff --git a/usr/src/sp1/head/mm/vm.h b/usr/src/sp1/head/mm/vm.h
index 8baaa06..5cba19b 100644
--- a/usr/src/sp1/head/mm/vm.h
+++ b/usr/src/sp1/head/mm/vm.h
@@ -12,8 +12,25 @@
 #ifndef _MM_VM_H_
 #define _MM_VM_H_ 1
 
+#include <sys/types.h>
 #include <sys/param.h>
 #include <os/bpt.h>
+#include <mu/mmu.h>
+
+/*
+ * Represents a virtual memory mapping that can be made
+ *
+ * @ps:       Pagesize
+ * @vma_base: Virtual memory base
+ * @pma_base: Physical memory base
+ * @length:   Number of bytes to map
+ */
+struct vm_map {
+    pagesize_t ps;
+    uintptr_t vma_base;
+    uintptr_t pma_base;
+    size_t length;
+};
 
 /*
  * Macros used to convert physical to virtual addresses
@@ -24,6 +41,14 @@
 #define vma_to_pma(vma) \
     (uintptr_t)PTR_NOFFSET(vma, bpt_kload_base())
 
+/*
+ * Create a virtual memory mapping
+ *
+ * @vfr:     Virtual fuck region to map within
+ * @mapping: Mapping to create
+ */
+status_t mm_vm_map(struct mmu_vfr *vfr, struct vm_map *mapping, int prot);
+
 /*
  * Initialize the virtual memory management
  */