lib: Create a separate math helper function file

There may be few common mathematics helper functions which can be used
anywhere in OpenSBI project.

Add a separate math helper function file to add these functions.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

include/sbi/sbi_math.h

@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2020 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Atish Patra <atish.patra@wdc.com>
+ */
+
+#ifndef __SBI_MATH_H__
+#define __SBI_MATH_H__
+
+unsigned long log2roundup(unsigned long x);
+
+#endif

lib/sbi/objects.mk

@@ -24,6 +24,7 @@ libsbi-objs-y += sbi_ecall_vendor.o
 libsbi-objs-y += sbi_emulate_csr.o
 libsbi-objs-y += sbi_fifo.o
 libsbi-objs-y += sbi_hart.o
+libsbi-objs-y += sbi_math.o
 libsbi-objs-y += sbi_hfence.o
 libsbi-objs-y += sbi_hsm.o
 libsbi-objs-y += sbi_illegal_insn.o

lib/sbi/sbi_hart.c

@@ -15,6 +15,7 @@
 #include <sbi/sbi_console.h>
 #include <sbi/sbi_error.h>
 #include <sbi/sbi_hart.h>
+#include <sbi/sbi_math.h>
 #include <sbi/sbi_platform.h>
 
 extern void __sbi_expected_trap(void);
@@ -121,19 +122,6 @@ void sbi_hart_delegation_dump(struct sbi_scratch *scratch)
 #endif
 }
 
-unsigned long log2roundup(unsigned long x)
-{
-	unsigned long ret = 0;
-
-	while (ret < __riscv_xlen) {
-		if (x <= (1UL << ret))
-			break;
-		ret++;
-	}
-
-	return ret;
-}
-
 void sbi_hart_pmp_dump(struct sbi_scratch *scratch)
 {
 	const struct sbi_platform *plat = sbi_platform_ptr(scratch);

lib/sbi/sbi_math.c

@@ -0,0 +1,23 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2020 Western Digital Corporation or its affiliates.
+ *
+ * Common helper functions used across OpenSBI project.
+ *
+ * Authors:
+ *   Atish Patra <atish.patra@wdc.com>
+ */
+
+unsigned long log2roundup(unsigned long x)
+{
+	unsigned long ret = 0;
+
+	while (ret < __riscv_xlen) {
+		if (x <= (1UL << ret))
+			break;
+		ret++;
+	}
+
+	return ret;
+}