arch/x86: Add API to check if cache sets are power-of-two

Introduce a function to determine whether the number of cache sets is
a power of two. This aligns with common cache design practices that
favor power-of-two counts for efficient indexing and addressing.

BUG=b:306677879
BRANCH=firmware-rex-15709.B
TEST=Verified functionality on google/ovis and google/rex (including
a non-power-of-two Ovis configuration).

Change-Id: I819e0d1aeb4c1dbe1cdf3115b2e172588a6e8da5
Signed-off-by: Subrata Banik <subratabanik@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/81268
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/arch/x86/cpu_common.c

@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
+#include <commonlib/helpers.h>
 #include <cpu/cpu.h>
 #include <types.h>
 
@@ -234,3 +235,18 @@ bool fill_cpu_cache_info(uint8_t level, struct cpu_cache_info *info)
 
 	return true;
 }
+
+bool is_cache_sets_power_of_two(void)
+{
+	struct cpu_cache_info info;
+
+	if (!fill_cpu_cache_info(CACHE_L3, &info))
+		return false;
+
+	size_t cache_sets = cpu_get_cache_sets(&info);
+
+	if (IS_POWER_OF_2(cache_sets))
+		return true;
+
+	return false;
+}

src/arch/x86/include/arch/cpu.h

@@ -329,6 +329,15 @@ uint8_t cpu_get_c_substate_support(const int state);
  */
 bool fill_cpu_cache_info(uint8_t level, struct cpu_cache_info *info);
 
+/*
+ * Determines whether the number of cache sets is a power of two.
+ *
+ * Cache designs often favor power-of-two set counts for efficient indexing
+ * and addressing. This function checks if the provided cache configuration
+ * adheres to this practice.
+ */
+bool is_cache_sets_power_of_two(void);
+
 #if CONFIG(RESERVED_PHYSICAL_ADDRESS_BITS_SUPPORT)
 unsigned int get_reserved_phys_addr_bits(void);
 #else