MPAM needs to know the size of a cache associated with a particular CPU.
The DT/ACPI agnostic way of doing this is to ask cacheinfo.

Add a helper to do this.

Signed-off-by: James Morse <james.morse@arm.com>

---
Changes since v1:
 * Converted to kdoc.
 * Simplified helper to use get_cpu_cacheinfo_level().
---
 include/linux/cacheinfo.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/include/linux/cacheinfo.h b/include/linux/cacheinfo.h
index 2dcbb69139e9..e12d6f2c6a57 100644
--- a/include/linux/cacheinfo.h
+++ b/include/linux/cacheinfo.h
@@ -148,6 +148,21 @@ static inline int get_cpu_cacheinfo_id(int cpu, int level)
 	return ci ? ci->id : -1;
 }
 
+/**
+ * get_cpu_cacheinfo_size() - Get the size of the cache.
+ * @cpu:      The cpu that is associated with the cache.
+ * @level:    The level of the cache as seen by @cpu.
+ *
+ * Callers must hold the cpuhp lock.
+ * Returns the cache-size on success, or 0 for an error.
+ */
+static inline unsigned int get_cpu_cacheinfo_size(int cpu, int level)
+{
+	struct cacheinfo *ci = get_cpu_cacheinfo_level(cpu, level);
+
+	return ci ? ci->size : 0;
+}
+
 #if defined(CONFIG_ARM64) || defined(CONFIG_ARM)
 #define use_arch_cache_info()	(true)
 #else
-- 
2.20.1