os/amd64: Reduce coupling with VAS structure

This commit moves the VAS structure into a standard MD layer side and
makes it accessible through a standard MI layer header. This indirection
reduces coupling so that the codebase wont break if a name change or
anything is needed.

Signed-off-by: Ian Moffett <ian@osmora.org>

2 files changed, 45 insertions, 9 deletions

diff --git a/src/sys/include/arch/amd64/vas.h b/src/sys/include/arch/amd64/vas.h
new file mode 100644
index 0000000..3afb88e
--- /dev/null
+++ b/src/sys/include/arch/amd64/vas.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2025 Ian Marco Moffett and L5 engineers
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _MACHINE_VAS_H_
+#define _MACHINE_VAS_H_ 1
+
+#include <vm/vm.h>
+
+/*
+ * Represents the current virtual address
+ *
+ * @cr3: The value of CR3 for this VAS
+ */
+struct vm_vas {
+    paddr_t cr3;
+};
+
+#endif  /* !_MACHINE_VAS_H_ */
diff --git a/src/sys/include/vm/mmu.h b/src/sys/include/vm/mmu.h
index 0edd0bc..6749254 100644
--- a/src/sys/include/vm/mmu.h
+++ b/src/sys/include/vm/mmu.h
@@ -38,6 +38,7 @@
 #include <sys/cpuvar.h>
 #include <sys/mman.h>
 #include <sys/param.h>
+#include <machine/vas.h>    /* standard */
 #include <vm/vm.h>
 
 /*
@@ -61,15 +62,6 @@ struct mmu_map {
 };
 
 /*
- * Represents the current virtual address
- *
- * @cr3: The value of CR3 for this VAS
- */
-struct vm_vas {
-    paddr_t cr3;
-};
-
-/*
  * Global early kernel VAS structure used in the
  * creation of new virtual address spaces.
  */