[PATCH v6 07/12] drivers: base cacheinfo: Add support for ACPI based firmware tables

[Jeremy Linton]

Add a entry to to struct cacheinfo to maintain a reference to the PPTT
node which can be used to match identical caches across cores. Also
stub out cache_setup_acpi() so that individual architectures can
enable ACPI topology parsing.

Signed-off-by: Jeremy Linton <jeremy.linton at arm.com>
---
 drivers/acpi/pptt.c       |  1 +
 drivers/base/cacheinfo.c  | 20 +++++++++++++-------
 include/linux/cacheinfo.h |  9 +++++++++
 3 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c
index 2c4b3ed862a8..4f5ab19c3a08 100644
--- a/drivers/acpi/pptt.c
+++ b/drivers/acpi/pptt.c
@@ -329,6 +329,7 @@ static void update_cache_properties(struct cacheinfo *this_leaf,
 {
 	int valid_flags = 0;
 
+	this_leaf->fw_unique = cpu_node;
 	if (found_cache->flags & ACPI_PPTT_SIZE_PROPERTY_VALID) {
 		this_leaf->size = found_cache->size;
 		valid_flags++;
diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index 217aa90fb036..ee51e33cc37c 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -208,16 +208,16 @@ static int cache_setup_of_node(unsigned int cpu)
 
 	if (index != cache_leaves(cpu)) /* not all OF nodes populated */
 		return -ENOENT;
-
 	return 0;
 }
+
 #else
 static inline int cache_setup_of_node(unsigned int cpu) { return 0; }
 static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
 					   struct cacheinfo *sib_leaf)
 {
 	/*
-	 * For non-DT systems, assume unique level 1 cache, system-wide
+	 * For non-DT/ACPI systems, assume unique level 1 caches, system-wide
 	 * shared caches for all other levels. This will be used only if
 	 * arch specific code has not populated shared_cpu_map
 	 */
@@ -225,6 +225,11 @@ static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
 }
 #endif
 
+int __weak cache_setup_acpi(unsigned int cpu)
+{
+	return -ENOTSUPP;
+}
+
 static int cache_shared_cpu_map_setup(unsigned int cpu)
 {
 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
@@ -235,11 +240,11 @@ static int cache_shared_cpu_map_setup(unsigned int cpu)
 	if (this_cpu_ci->cpu_map_populated)
 		return 0;
 
-	if (of_have_populated_dt())
+	if (!acpi_disabled)
+		ret = cache_setup_acpi(cpu);
+	else if (of_have_populated_dt())
 		ret = cache_setup_of_node(cpu);
-	else if (!acpi_disabled)
-		/* No cache property/hierarchy support yet in ACPI */
-		ret = -ENOTSUPP;
+
 	if (ret)
 		return ret;
 
@@ -290,7 +295,8 @@ static void cache_shared_cpu_map_remove(unsigned int cpu)
 			cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
 			cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
 		}
-		of_node_put(this_leaf->fw_unique);
+		if (of_have_populated_dt())
+			of_node_put(this_leaf->fw_unique);
 	}
 }
 
diff --git a/include/linux/cacheinfo.h b/include/linux/cacheinfo.h
index 6f2e6c87b64c..65b0ae30016e 100644
--- a/include/linux/cacheinfo.h
+++ b/include/linux/cacheinfo.h
@@ -98,6 +98,15 @@ struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu);
 int init_cache_level(unsigned int cpu);
 int populate_cache_leaves(unsigned int cpu);
 void cache_of_set_props(struct cacheinfo *this_leaf, struct device_node *np);
+int cache_setup_acpi(unsigned int cpu);
+int acpi_find_last_cache_level(unsigned int cpu);
+#ifndef CONFIG_ACPI
+int acpi_find_last_cache_level(unsigned int cpu)
+{
+	/*ACPI kernels should be built with PPTT support*/
+	return 0;
+}
+#endif
 
 const struct attribute_group *cache_get_priv_group(struct cacheinfo *this_leaf);
 
-- 
2.13.5