[arch] have each arch define ARCH_HAS_MMU

This lets some code decide whether or not there's any mmu
present to use. Also kernel VM will complain if it isn't set
as an extra safety.

arch/arm/arm/arch.c

@@ -26,7 +26,9 @@
 #include <platform.h>
 #include <target.h>
 #include <kernel/thread.h>
+#if WITH_KERNEL_VM
 #include <kernel/vm.h>
+#endif
 
 #define LOCAL_TRACE 0
 
@@ -68,7 +70,7 @@ void arch_early_init(void) {
     *REG32(scu_base) |= (1<<0); /* enable SCU */
 #endif
 
-#if ARM_WITH_MMU
+#if ARCH_HAS_MMU
     arm_mmu_early_init();
 
     platform_init_mmu_mappings();
@@ -137,7 +139,7 @@ void arch_init(void) {
 
     //spinlock_test();
 
-#if ARM_WITH_MMU
+#if ARCH_HAS_MMU
     /* finish initializing the mmu */
     arm_mmu_init();
 #endif

arch/arm/arm/mmu.c

@@ -5,6 +5,8 @@
  * license that can be found in the LICENSE file or at
  * https://opensource.org/licenses/MIT
  */
+#if ARCH_HAS_MMU
+
 #include <lk/debug.h>
 #include <lk/trace.h>
 #include <stdlib.h>
@@ -23,8 +25,6 @@
 #define LOCAL_TRACE 0
 #define TRACE_CONTEXT_SWITCH 0
 
-#if ARM_WITH_MMU
-
 #define IS_SECTION_ALIGNED(x) IS_ALIGNED(x, SECTION_SIZE)
 #define IS_SUPERSECTION_ALIGNED(x) IS_ALIGNED(x, SUPERSECTION_SIZE)
 
@@ -724,4 +724,4 @@ status_t arch_mmu_destroy_aspace(arch_aspace_t *aspace) {
     return NO_ERROR;
 }
 
-#endif // ARM_WITH_MMU
+#endif // ARCH_HAS_MMU

arch/arm/arm/start.S

@@ -8,7 +8,10 @@
 #include <lk/asm.h>
 #include <arch/arm/cores.h>
 #include <arch/arm/mmu.h>
+
+#if WITH_KERNEL_VM
 #include <kernel/vm.h>
+#endif
 
 .section ".text.boot"
 .globl _start
@@ -106,7 +109,7 @@ arm_reset:
 .Lrelocate_done:
 #endif // !WITH_NO_PHYS_RELOCATION
 
-#if ARM_WITH_MMU
+#if ARCH_HAS_MMU
 .Lsetup_mmu:
 
     /* set up the mmu according to mmu_initial_mappings */
@@ -212,7 +215,7 @@ arm_reset:
 
     /* set up the mmu */
     bl      .Lmmu_setup
-#endif // ARM_WITH_MMU
+#endif // ARCH_HAS_MMU
 
     /* at this point we're running at our final location in virtual memory (if enabled) */
 .Lstack_setup:

arch/arm/rules.mk

@@ -98,7 +98,7 @@ endif
 ifeq ($(ARM_CPU),cortex-a7)
 GLOBAL_DEFINES += \
 	ARM_WITH_CP15=1 \
-	ARM_WITH_MMU=1 \
+	ARCH_HAS_MMU=1 \
 	ARM_ISA_ARMv7=1 \
 	ARM_ISA_ARMv7A=1 \
 	ARM_WITH_VFP=1 \
@@ -112,7 +112,7 @@ endif
 ifeq ($(ARM_CPU),cortex-a15)
 GLOBAL_DEFINES += \
 	ARM_WITH_CP15=1 \
-	ARM_WITH_MMU=1 \
+	ARCH_HAS_MMU=1 \
 	ARM_ISA_ARMv7=1 \
 	ARM_ISA_ARMv7A=1 \
 	ARM_WITH_THUMB=1 \
@@ -129,7 +129,7 @@ endif
 ifeq ($(ARM_CPU),cortex-a8)
 GLOBAL_DEFINES += \
 	ARM_WITH_CP15=1 \
-	ARM_WITH_MMU=1 \
+	ARCH_HAS_MMU=1 \
 	ARM_ISA_ARMv7=1 \
 	ARM_ISA_ARMv7A=1 \
 	ARM_WITH_VFP=1 \
@@ -143,7 +143,7 @@ endif
 ifeq ($(ARM_CPU),cortex-a9)
 GLOBAL_DEFINES += \
 	ARM_WITH_CP15=1 \
-	ARM_WITH_MMU=1 \
+	ARCH_HAS_MMU=1 \
 	ARM_ISA_ARMv7=1 \
 	ARM_ISA_ARMv7A=1 \
 	ARM_WITH_THUMB=1 \
@@ -155,7 +155,7 @@ ifeq ($(ARM_CPU),cortex-a9-neon)
 GLOBAL_DEFINES += \
 	ARM_CPU_CORTEX_A9=1 \
 	ARM_WITH_CP15=1 \
-	ARM_WITH_MMU=1 \
+	ARCH_HAS_MMU=1 \
 	ARM_ISA_ARMv7=1 \
 	ARM_ISA_ARMv7A=1 \
 	ARM_WITH_VFP=1 \
@@ -168,7 +168,7 @@ endif
 ifeq ($(ARM_CPU),arm1136j-s)
 GLOBAL_DEFINES += \
 	ARM_WITH_CP15=1 \
-	ARM_WITH_MMU=1 \
+	ARCH_HAS_MMU=1 \
 	ARM_ISA_ARMv6=1 \
 	ARM_WITH_THUMB=1 \
 	ARM_WITH_CACHE=1 \
@@ -178,7 +178,7 @@ endif
 ifeq ($(ARM_CPU),arm1176jzf-s)
 GLOBAL_DEFINES += \
 	ARM_WITH_CP15=1 \
-	ARM_WITH_MMU=1 \
+	ARCH_HAS_MMU=1 \
 	ARM_ISA_ARMv6=1 \
 	ARM_WITH_VFP=1 \
 	ARM_WITH_THUMB=1 \

arch/arm64/rules.mk

@@ -65,7 +65,8 @@ GLOBAL_DEFINES += \
     KERNEL_ASPACE_BASE=$(KERNEL_ASPACE_BASE) \
     KERNEL_ASPACE_SIZE=$(KERNEL_ASPACE_SIZE) \
     USER_ASPACE_BASE=$(USER_ASPACE_BASE) \
-    USER_ASPACE_SIZE=$(USER_ASPACE_SIZE)
+    USER_ASPACE_SIZE=$(USER_ASPACE_SIZE) \
+    ARCH_HAS_MMU=1
 
 KERNEL_BASE ?= $(KERNEL_ASPACE_BASE)
 KERNEL_LOAD_OFFSET ?= 0

arch/include/arch/mmu.h

@@ -7,6 +7,8 @@
  */
 #pragma once
 
+#if ARCH_HAS_MMU
+
 #include <arch.h>
 #include <sys/types.h>
 #include <lk/compiler.h>
@@ -55,3 +57,5 @@ void arch_disable_mmu(void);
 
 __END_CDECLS
 
+#endif
+

arch/or1k/rules.mk

@@ -41,6 +41,12 @@ GLOBAL_DEFINES += \
     MEMBASE=$(MEMBASE) \
     MEMSIZE=$(MEMSIZE)
 
+# we have an mmu
+WITH_KERNEL_VM=1
+
+GLOBAL_DEFINES += \
+    ARCH_HAS_MMU=1
+
 # potentially generated files that should be cleaned out with clean make rule
 GENERATED += \
 	$(BUILDDIR)/linker.ld

arch/riscv/arch.c

@@ -59,7 +59,6 @@ void arch_early_init(void) {
 
 #if RISCV_S_MODE
     sbi_early_init();
-
 #endif
 #if RISCV_MMU
     riscv_early_mmu_init();

arch/riscv/rules.mk

@@ -89,6 +89,7 @@ endif
 ifeq ($(WITH_KERNEL_VM),1)
 
 GLOBAL_DEFINES += \
+    ARCH_HAS_MMU=1 \
     KERNEL_ASPACE_BASE=$(KERNEL_ASPACE_BASE) \
     KERNEL_ASPACE_SIZE=$(KERNEL_ASPACE_SIZE) \
     USER_ASPACE_BASE=$(USER_ASPACE_BASE) \

arch/x86/rules.mk

@@ -38,7 +38,8 @@ GLOBAL_DEFINES += \
 	KERNEL_LOAD_OFFSET=$(KERNEL_LOAD_OFFSET) \
 	KERNEL_ASPACE_BASE=$(KERNEL_ASPACE_BASE) \
 	KERNEL_ASPACE_SIZE=$(KERNEL_ASPACE_SIZE) \
-	SMP_MAX_CPUS=1
+	SMP_MAX_CPUS=1 \
+	ARCH_HAS_MMU=1
 
 MODULE_SRCS += \
 	$(SUBARCH_DIR)/start.S \

kernel/include/kernel/vm.h

@@ -28,6 +28,10 @@
 #define MMU_INITIAL_MAPPING_FLAG_DEVICE   (0x4)
 #define MMU_INITIAL_MAPPING_FLAG_DYNAMIC  (0x8)  /* entry has to be patched up by platform_reset */
 
+#if !ARCH_HAS_MMU
+#error ARCH needs to declare mmu support
+#endif
+
 #ifndef ASSEMBLY
 
 #include <arch.h>

platform/or1ksim/platform.c

@@ -7,7 +7,6 @@
  */
 #include <lk/reg.h>
 #include <kernel/thread.h>
-#include <kernel/vm.h>
 #include <dev/uart.h>
 #include <dev/timer/or1k_ticktimer.h>
 #include <platform.h>
@@ -17,6 +16,9 @@
 #include <platform/or1ksim.h>
 #include <sys/types.h>
 #include <target/debugconfig.h>
+#if WITH_KERNEL_VM
+#include <kernel/vm.h>
+#endif
 
 struct mmu_initial_mapping mmu_initial_mappings[] = {
     /* 32 MB of RAM space */

platform/or1ksim/rules.mk

@@ -16,9 +16,6 @@ MODULE_SRCS += \
 MEMBASE ?= 0x00000000
 MEMSIZE ?= 0x02000000
 
-# we have an mmu
-WITH_KERNEL_VM=1
-
 KERNEL_BASE = 0xc0000000
 
 include make/module.mk