Set cpu_rdmsr_range() and get_bits_value() as public functions

libcpuid/exports.def

@@ -30,3 +30,5 @@ cpu_clock_by_ic @26
 cpuid_get_total_cpus @27
 cpu_msr_driver_open_core @28
 cpuid_get_vendor @29
+cpu_rdmsr_range @30
+get_bits_value @31

libcpuid/libcpuid.h

@@ -882,6 +882,36 @@ typedef enum {
 	                            multiplied by 100. */
 } cpu_msrinfo_request_t;
 
+/**
+ * @brief Similar to \ref cpu_rdmsr, but extract a range of bits
+ *
+ * It is similar to use \ref cpu_rdmsr then \ref get_bits_value.
+ *
+ * @param handle - a handle to the MSR reader driver, as created by
+ *                 cpu_msr_driver_open
+ * @param msr_index - the numeric ID of the MSR you want to read
+ * @param highbit - the high bit in range, must be inferior to 64
+ * @param lowbit - the low bit in range, must be equal or superior to 0
+ * @param result - a pointer to a 64-bit integer, where the MSR value is stored
+ *
+ * @returns zero if successful, and some negative number on error.
+ *          The error message can be obtained by calling \ref cpuid_error.
+ *          @see cpu_error_t
+ */
+int cpu_rdmsr_range(struct msr_driver_t* handle, uint32_t msr_index, uint8_t highbit,
+                    uint8_t lowbit, uint64_t* result);
+
+/**
+ * @brief Extract a range of bits from MSR value
+ *
+ * @param val - a 64-bit integer, where the MSR value is stored
+ * @param highbit - the high bit in range, must be inferior to 64
+ * @param lowbit - the low bit in range, must be equal or superior to 0
+ *
+ * @returns bits between highbit and lowbit
+ */
+uint64_t get_bits_value(uint64_t val, int highbit, int lowbit);
+
 /**
  * @brief Reads extended CPU information from Model-Specific Registers.
  * @param handle - a handle to an open MSR driver, @see cpu_msr_driver_open

libcpuid/libcpuid.sym

@@ -27,3 +27,5 @@ cpu_clock_by_ic
 cpuid_get_total_cpus
 cpu_msr_driver_open_core
 cpuid_get_vendor
+cpu_rdmsr_range
+get_bits_value

libcpuid/rdmsr.c

@@ -420,7 +420,20 @@ static int perfmsr_measure(struct msr_driver_t* handle, int msr)
 #define MSR_PSTATE_S 0xC0010063
 #define MSR_PSTATE_0 0xC0010064
 
-static uint64_t get_bits_value(uint64_t val, int highbit, int lowbit)
+int cpu_rdmsr_range(struct msr_driver_t* handle, uint32_t msr_index, uint8_t highbit,
+                    uint8_t lowbit, uint64_t* result)
+{
+	if(highbit > 63 || lowbit > highbit)
+		return set_error(ERR_INVRANGE);
+
+	if(cpu_rdmsr(handle, msr_index, result))
+		return set_error(ERR_HANDLE_R);
+
+	*result = get_bits_value(*result, highbit, lowbit);
+	return 0;
+}
+
+uint64_t get_bits_value(uint64_t val, int highbit, int lowbit)
 {
 	uint64_t data = val;
 	const uint8_t bits = highbit - lowbit + 1;
@@ -434,19 +447,6 @@ static uint64_t get_bits_value(uint64_t val, int highbit, int lowbit)
 	return data;
 }
 
-static int cpu_rdmsr_range(struct msr_driver_t* handle, uint32_t msr_index, uint8_t highbit,
-                    uint8_t lowbit, uint64_t* result)
-{
-	if(highbit > 63 || lowbit > highbit)
-		return set_error(ERR_INVRANGE);
-
-	if(cpu_rdmsr(handle, msr_index, result))
-		return set_error(ERR_HANDLE_R);
-
-	*result = get_bits_value(*result, highbit, lowbit);
-	return 0;
-}
-
 int cpu_msrinfo(struct msr_driver_t* handle, cpu_msrinfo_request_t which)
 {
 	uint64_t r;