Squash commits for public release

kernel/include/platform/riscv64/registers.h

@@ -0,0 +1,40 @@
+#ifndef _KERNEL_PLATFORM_RISCV64_REGISTERS_H
+#define _KERNEL_PLATFORM_RISCV64_REGISTERS_H
+
+#include <libkern/types.h>
+#include <platform/riscv64/system.h>
+
+extern uint64_t read_ip();
+static inline uint64_t read_scause()
+{
+    uint64_t x;
+    asm volatile("csrr %0, scause"
+                 : "=r"(x));
+    return x;
+}
+
+static inline uint64_t read_stval()
+{
+    uint64_t x;
+    asm volatile("csrr %0, stval"
+                 : "=r"(x));
+    return x;
+}
+
+static inline uint64_t read_sip()
+{
+    uint64_t x;
+    asm volatile("csrr %0, sip"
+                 : "=r"(x));
+    return x;
+}
+
+static inline void write_sip(uint64_t val)
+{
+    asm volatile("csrw sip, %0"
+                 :
+                 : "r"(val)
+                 : "memory");
+}
+
+#endif /* _KERNEL_PLATFORM_RISCV64_REGISTERS_H */