cpuid crate refactoring - part 2

- move leaf handlers into separate functions
- test leaf handlers individually
- move all the templates into a folder

Signed-off-by: Serban Iorga <seriorga@amazon.com>

cpuid/src/bit_helper.rs

@@ -89,6 +89,10 @@ impl BitRangeExt<u32> for BitRange {
 /// Trait containing helper methods for bit operations.
 ///
 pub trait BitHelper {
+    /// Reads the value of the bit at position `pos`
+    ///
+    fn read_bit(&self, pos: u32) -> bool;
+
     /// Changes the value of the bit at position `pos` to `val`
     ///
     fn write_bit(&mut self, pos: u32, val: bool) -> &mut Self;
@@ -144,6 +148,12 @@ pub trait BitHelper {
 }
 
 impl BitHelper for u32 {
+    fn read_bit(&self, pos: u32) -> bool {
+        assert!(pos <= MAX_U32_BIT_INDEX, "Invalid pos");
+
+        (*self & (1 << pos)) > 0
+    }
+
     fn write_bit(&mut self, pos: u32, val: bool) -> &mut Self {
         assert!(pos <= MAX_U32_BIT_INDEX, "Invalid pos");
 
@@ -215,6 +225,22 @@ mod tests {
         assert!(val == 0);
     }
 
+    #[test]
+    #[should_panic]
+    fn test_invalid_read_bit() {
+        // Set bit to 1
+        let val: u32 = 0;
+        val.read_bit(32);
+    }
+
+    #[test]
+    fn test_simple_read_bit() {
+        // Set bit to 1
+        let val: u32 = 0b100000;
+        assert!(val.read_bit(5));
+        assert!(!val.read_bit(4));
+    }
+
     #[test]
     fn test_chained_write_bit() {
         let mut val: u32 = 1 << 12;

cpuid/src/brand_string.rs

@@ -4,7 +4,7 @@
 use std::arch::x86_64::__cpuid as host_cpuid;
 use std::slice;
 
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Clone)]
 pub enum Error {
     NotSupported,
     Overflow(String),
@@ -23,6 +23,7 @@ pub enum Reg {
 /// This is achieved by bypassing the `O(n)` indexing, heap allocation, and the unicode checks
 /// done by `std::string::String`.
 ///
+#[derive(Clone)]
 pub struct BrandString {
     /// Flattened buffer, holding an array of 32-bit register values.
     ///

cpuid/src/cpu_leaf.rs

@@ -81,11 +81,11 @@ pub mod leaf_0x4 {
             msb_index: 7,
             lsb_index: 5,
         };
-        pub const MAX_ADDR_IDS_SHARING_CACHE_BITRANGE: BitRange = BitRange {
+        pub const MAX_CPUS_PER_CORE: BitRange = BitRange {
             msb_index: 25,
             lsb_index: 14,
         };
-        pub const MAX_ADDR_IDS_IN_PACKAGE_BITRANGE: BitRange = BitRange {
+        pub const MAX_CORES_PER_PACKAGE: BitRange = BitRange {
             msb_index: 31,
             lsb_index: 26,
         };