From 61df56a7f350651fa5ca0d4c08409ef4d897edaf Mon Sep 17 00:00:00 2001
From: Adrian Danis <Adrian.Danis@data61.csiro.au>
Date: Fri, 6 Apr 2018 11:45:33 +1000
Subject: [PATCH] riscv: Remove VMNoAccess mapping type

A frame cannot be mapped without any access permissions, as this encoding is used to
represent a page table mapping.
---
 include/arch/riscv/arch/object/structures.h | 9 ++++-----
 src/arch/riscv/kernel/vspace.c              | 9 +++------
 2 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/include/arch/riscv/arch/object/structures.h b/include/arch/riscv/arch/object/structures.h
index a042bd2d9..255ae5997 100644
--- a/include/arch/riscv/arch/object/structures.h
+++ b/include/arch/riscv/arch/object/structures.h
@@ -50,11 +50,10 @@ typedef struct arch_tcb {
 } arch_tcb_t;
 
 enum vm_rights {
-    VMNoAccess = 0,
-    VMKernelOnly = 1,
-    VMReadOnly = 2,
-    VMWriteOnly = 3,
-    VMReadWrite = 4
+    VMKernelOnly = 0,
+    VMReadOnly = 1,
+    VMWriteOnly = 2,
+    VMReadWrite = 3
 };
 typedef uint32_t vm_rights_t;
 
diff --git a/src/arch/riscv/kernel/vspace.c b/src/arch/riscv/kernel/vspace.c
index 637a6a7a2..9257ae6e5 100644
--- a/src/arch/riscv/kernel/vspace.c
+++ b/src/arch/riscv/kernel/vspace.c
@@ -48,7 +48,7 @@ static exception_t performPageGetAddress(void *vbase_ptr);
 static word_t CONST
 RISCVGetWriteFromVMRights(vm_rights_t vm_rights)
 {
-    return (vm_rights != VMNoAccess) && (vm_rights != VMReadOnly);
+    return vm_rights != VMReadOnly;
 }
 
 static word_t RISCVGetUserFromVMRights(vm_rights_t vm_rights)
@@ -59,7 +59,7 @@ static word_t RISCVGetUserFromVMRights(vm_rights_t vm_rights)
 static inline word_t CONST
 RISCVGetReadFromVMRights(vm_rights_t vm_rights)
 {
-    return (vm_rights != VMNoAccess) && (vm_rights != VMWriteOnly);
+    return vm_rights != VMWriteOnly;
 }
 
 /* ==================== BOOT CODE STARTS HERE ==================== */
@@ -664,9 +664,6 @@ checkValidIPCBuffer(vptr_t vptr, cap_t cap)
 vm_rights_t CONST
 maskVMRights(vm_rights_t vm_rights, seL4_CapRights_t cap_rights_mask)
 {
-    if (vm_rights == VMNoAccess) {
-        return VMNoAccess;
-    }
     if (vm_rights == VMReadOnly &&
             seL4_CapRights_get_capAllowRead(cap_rights_mask)) {
         return VMReadOnly;
@@ -688,7 +685,7 @@ maskVMRights(vm_rights_t vm_rights, seL4_CapRights_t cap_rights_mask)
     if (vm_rights == VMKernelOnly) {
         return VMKernelOnly;
     }
-    return VMNoAccess;
+    return VMKernelOnly;
 }
 
 /* The rest of the file implements the RISCV object invocations */