================
This problem appears to have been introduced in 2.6.29 by
the commit in the Fixes line below.
This caused lscpu to error out on e500v2 devices, and probably others
error: cannot open /sys/devices/system/cpu/cpu0/cache/index2/size: No such file or directory
Some embedded powerpc systems use cache-size in DTS for the unified L2 cache
size, not d-cache-size, so we need to allow for both DTS names. Added a
new CACHE_TYPE_UNIFIED_D cache_type_info structure to handle this.
Fixes: 93197a36a9c16a85fb24cf5a8639f7bf9af838a3
Signed-off-by: Dave Olson <olson@cumulusnetworks.com>
---
arch/powerpc/kernel/cacheinfo.c | 44 ++++++++++++++++++++++++++++++---------
1 file changed, 34 insertions(+), 10 deletions(-)
@@ -61,12 +61,22 @@ struct cache_type_info {
};
/* These are used to index the cache_type_info array. */
-#define CACHE_TYPE_UNIFIED 0
-#define CACHE_TYPE_INSTRUCTION 1
-#define CACHE_TYPE_DATA 2
+#define CACHE_TYPE_UNIFIED 0 /* cache-size, cache-block-size, etc. */
+#define CACHE_TYPE_UNIFIED_D 1 /* d-cache-size, d-cache-block-size, etc */
+#define CACHE_TYPE_INSTRUCTION 2
+#define CACHE_TYPE_DATA 3
static const struct cache_type_info cache_type_info[] = {
{
+ /* Embedded systems that use cache-size, cache-block-size,
+ * etc. for the Unified (typically L2) cache. */
+ .name = "Unified",
+ .size_prop = "cache-size",
+ .line_size_props = { "cache-line-size",
+ "cache-block-size", },
+ .nr_sets_prop = "cache-sets",
+ },
+ {
/* PowerPC Processor binding says the [di]-cache-*
* must be equal on unified caches, so just use
* d-cache properties. */
@@ -293,7 +303,8 @@ static struct cache *cache_find_first_sibling(struct cache *cache)
{
struct cache *iter;
- if (cache->type == CACHE_TYPE_UNIFIED)
+ if (cache->type == CACHE_TYPE_UNIFIED ||
+ cache->type == CACHE_TYPE_UNIFIED_D)
return cache;
list_for_each_entry(iter, &cache_list, list)
@@ -324,16 +335,29 @@ static bool cache_node_is_unified(const struct device_node *np)
return of_get_property(np, "cache-unified", NULL);
}
-static struct cache *cache_do_one_devnode_unified(struct device_node *node,
- int level)
+/*
+ * Unified caches can have two different sets of tags. Most embedded
+ * use cache-size, etc. for the unified cache size, but open firmware systems
+ * use d-cache-size, etc. Check on initialization for which type we have, and
+ * return the appropriate structure type. Assume it's embedded if it isn't
+ * open firmware. If it's yet a 3rd type, then there will be missing entries
+ * in /sys/devices/system/cpu/cpu0/cache/index2/, and this code will need
+ * to be extended further.
+ */
+static int cache_is_unified_d(const struct device_node *np)
{
- struct cache *cache;
+ return of_get_property(np,
+ cache_type_info[CACHE_TYPE_UNIFIED_D].size_prop, NULL) ?
+ CACHE_TYPE_UNIFIED_D : CACHE_TYPE_UNIFIED;
+}
+/*
+ */
+static struct cache *cache_do_one_devnode_unified(struct device_node *node, int level)
+{
pr_debug("creating L%d ucache for %s\n", level, node->full_name);
- cache = new_cache(CACHE_TYPE_UNIFIED, level, node);
-
- return cache;
+ return new_cache(cache_is_unified_d(node), level, node);
}
static struct cache *cache_do_one_devnode_split(struct device_node *node,
From: Dave Olson <olson@cumulusnetworks.com> This is version 5 of the patch, incorporating Michael Ellerman's suggested changes from March 26, 2015. v5 removes the __cpuinit that had crept in from my patch based on an older kernel, but is otherwise the same as v4.