Squash commits for public release

kernel/include/platform/arm64/fpu/fpu.h

@@ -0,0 +1,44 @@
+#ifndef _KERNEL_PLATFORM_ARM64_FPU_FPU_H
+#define _KERNEL_PLATFORM_ARM64_FPU_FPU_H
+
+#include <libkern/kassert.h>
+#include <libkern/types.h>
+#include <platform/arm64/registers.h>
+
+#define FPU_STATE_ALIGNMENT (32)
+
+typedef struct {
+    uint64_t halfv[64];
+} __attribute__((aligned(FPU_STATE_ALIGNMENT))) fpu_state_t;
+
+void fpu_install();
+void fpu_init_state(fpu_state_t* new_fpu_state);
+extern void fpu_save(void*);
+extern void fpu_restore(void*);
+
+static inline void fpu_enable()
+{
+}
+
+static inline void fpu_disable()
+{
+}
+
+static inline int fpu_is_avail()
+{
+    return (((read_cpacr() >> 20) & 0b11) == 0b11);
+}
+
+static inline void fpu_make_avail()
+{
+    write_cpacr(read_cpacr() | ((0b11) << 20));
+}
+
+static inline void fpu_make_unavail()
+{
+    // Simply turn it off to make it unavailble.
+    uint64_t val = read_cpacr() & (~((3ull) << 20));
+    write_cpacr(val | ((0b01) << 20));
+}
+
+#endif //_KERNEL_PLATFORM_ARM64_FPU_FPU_H