cacheinfo: Add helper to access any cache index for a given CPU

The cacheinfo for a given CPU at a given index is used at quite a few
places by fetching the base point for index 0 using the helper
per_cpu_cacheinfo(cpu) and offsetting it by the required index.

Instead, add another helper to fetch the required pointer directly and
use it to simplify and improve readability.

Link: https://lore.kernel.org/r/20220704101605.1318280-4-sudeep.holla@arm.com
Tested-by: Ionela Voinescu <ionela.voinescu@arm.com>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

drivers/base/cacheinfo.c

@@ -25,6 +25,8 @@ static DEFINE_PER_CPU(struct cpu_cacheinfo, ci_cpu_cacheinfo);
 #define ci_cacheinfo(cpu)	(&per_cpu(ci_cpu_cacheinfo, cpu))
 #define cache_leaves(cpu)	(ci_cacheinfo(cpu)->num_leaves)
 #define per_cpu_cacheinfo(cpu)	(ci_cacheinfo(cpu)->info_list)
+#define per_cpu_cacheinfo_idx(cpu, idx)		\
+				(per_cpu_cacheinfo(cpu) + (idx))
 
 struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu)
 {
@@ -172,7 +174,7 @@ static int cache_setup_of_node(unsigned int cpu)
 	}
 
 	while (index < cache_leaves(cpu)) {
-		this_leaf = this_cpu_ci->info_list + index;
+		this_leaf = per_cpu_cacheinfo_idx(cpu, index);
 		if (this_leaf->level != 1)
 			np = of_find_next_cache_node(np);
 		else
@@ -231,7 +233,7 @@ static int cache_shared_cpu_map_setup(unsigned int cpu)
 	for (index = 0; index < cache_leaves(cpu); index++) {
 		unsigned int i;
 
-		this_leaf = this_cpu_ci->info_list + index;
+		this_leaf = per_cpu_cacheinfo_idx(cpu, index);
 		/* skip if shared_cpu_map is already populated */
 		if (!cpumask_empty(&this_leaf->shared_cpu_map))
 			continue;
@@ -242,7 +244,7 @@ static int cache_shared_cpu_map_setup(unsigned int cpu)
 
 			if (i == cpu || !sib_cpu_ci->info_list)
 				continue;/* skip if itself or no cacheinfo */
-			sib_leaf = sib_cpu_ci->info_list + index;
+			sib_leaf = per_cpu_cacheinfo_idx(i, index);
 			if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
 				cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
 				cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
@@ -258,12 +260,11 @@ static int cache_shared_cpu_map_setup(unsigned int cpu)
 
 static void cache_shared_cpu_map_remove(unsigned int cpu)
 {
-	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 	struct cacheinfo *this_leaf, *sib_leaf;
 	unsigned int sibling, index;
 
 	for (index = 0; index < cache_leaves(cpu); index++) {
-		this_leaf = this_cpu_ci->info_list + index;
+		this_leaf = per_cpu_cacheinfo_idx(cpu, index);
 		for_each_cpu(sibling, &this_leaf->shared_cpu_map) {
 			struct cpu_cacheinfo *sib_cpu_ci;
 
@@ -274,7 +275,7 @@ static void cache_shared_cpu_map_remove(unsigned int cpu)
 			if (!sib_cpu_ci->info_list)
 				continue;
 
-			sib_leaf = sib_cpu_ci->info_list + index;
+			sib_leaf = per_cpu_cacheinfo_idx(sibling, index);
 			cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
 			cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
 		}
@@ -609,7 +610,6 @@ static int cache_add_dev(unsigned int cpu)
 	int rc;
 	struct device *ci_dev, *parent;
 	struct cacheinfo *this_leaf;
-	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 	const struct attribute_group **cache_groups;
 
 	rc = cpu_cache_sysfs_init(cpu);
@@ -618,7 +618,7 @@ static int cache_add_dev(unsigned int cpu)
 
 	parent = per_cpu_cache_dev(cpu);
 	for (i = 0; i < cache_leaves(cpu); i++) {
-		this_leaf = this_cpu_ci->info_list + i;
+		this_leaf = per_cpu_cacheinfo_idx(cpu, i);
 		if (this_leaf->disable_sysfs)
 			continue;
 		if (this_leaf->type == CACHE_TYPE_NOCACHE)