[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.lin...@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