arm: Miscellaneous build fixes

* Use atomic_get_and_set for return value
* Atomics are no longer volatile
* Add missing arch_cpu_pause stub
* Move arch_cpu_idle to arch_cpu header to match
  other architectures

headers/private/kernel/arch/arm/arch_cpu.h

@@ -75,6 +75,23 @@ extern addr_t arm_get_fp(void);
 extern int mmu_read_c1(void);
 extern int mmu_write_c1(int val);
 
+
+static inline void
+arch_cpu_pause(void)
+{
+	// TODO: ARM Priority pause call
+}
+
+
+static inline void
+arch_cpu_idle(void)
+{
+	uint32 Rd = 0;
+	asm volatile("mcr p15, 0, %[c7format], c7, c0, 4"
+		: : [c7format] "r" (Rd) );
+}
+
+
 #ifdef __cplusplus
 };
 #endif

src/system/kernel/arch/arm/arch_cpu.cpp

@@ -77,14 +77,6 @@ arch_cpu_init_post_modules(kernel_args *args)
 }
 
 
-void
-arch_cpu_idle(void)
-{
-	uint32 Rd = 0;
-	asm volatile("mcr p15, 0, %[c7format], c7, c0, 4" : : [c7format] "r" (Rd) );
-}
-
-
 status_t
 arch_cpu_shutdown(bool reboot)
 {

src/system/kernel/arch/arm/paging/32bit/ARMPagingMethod32Bit.h

@@ -103,7 +103,7 @@ ARMPagingMethod32Bit::Method()
 ARMPagingMethod32Bit::SetPageTableEntry(page_table_entry* entry,
 	page_table_entry newEntry)
 {
-	return atomic_set((int32*)entry, newEntry);
+	return atomic_get_and_set((int32*)entry, newEntry);
 }
 
 

src/system/kernel/arch/arm/paging/ARMPagingStructures.h

@@ -17,7 +17,7 @@
 
 struct ARMPagingStructures : DeferredDeletable {
 	uint32						pgdir_phys;
-	vint32						ref_count;
+	int32						ref_count;
 	vint32						active_on_cpus;
 		// mask indicating on which CPUs the map is currently used