The MPAM driver identifies caches by id for use with resctrl. It
needs to know the cache-id when probe-ing, but the value isn't set
in cacheinfo until device_initcall().
Expose the code that generates the cache-id. The parts of the MPAM
driver that run early can use this to set up the resctrl structures
before cacheinfo is ready in device_initcall().
Signed-off-by: James Morse <james.morse@xxxxxxx>
---
Changes since v1:
* Renamed cache_of_get_id() cache_of_calculate_id().
---
drivers/base/cacheinfo.c | 19 +++++++++++++------
include/linux/cacheinfo.h | 1 +
2 files changed, 14 insertions(+), 6 deletions(-)
diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index 613410705a47..f6289d142ba9 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -207,11 +207,10 @@ static bool match_cache_node(struct device_node *cpu,
#define arch_compact_of_hwid(_x) (_x)
#endif
-static void cache_of_set_id(struct cacheinfo *this_leaf,
- struct device_node *cache_node)
+unsigned long cache_of_calculate_id(struct device_node *cache_node)
{
struct device_node *cpu;
- u32 min_id = ~0;
+ unsigned long min_id = ~0UL;
for_each_of_cpu_node(cpu) {
u64 id = of_get_cpu_hwid(cpu, 0);
@@ -219,15 +218,23 @@ static void cache_of_set_id(struct cacheinfo *this_leaf,
id = arch_compact_of_hwid(id);
if (FIELD_GET(GENMASK_ULL(63, 32), id)) {
of_node_put(cpu);
- return;
+ return ~0UL;
}
if (match_cache_node(cpu, cache_node))
min_id = min(min_id, id);
}
- if (min_id != ~0) {
- this_leaf->id = min_id;
+ return min_id;
+}
+
+static void cache_of_set_id(struct cacheinfo *this_leaf,
+ struct device_node *cache_node)
+{
+ unsigned long id = cache_of_calculate_id(cache_node);
+
+ if (id != ~0UL) {
+ this_leaf->id = id;
this_leaf->attributes |= CACHE_ID;
}
}
diff --git a/include/linux/cacheinfo.h b/include/linux/cacheinfo.h
index c8f4f0a0b874..2dcbb69139e9 100644
--- a/include/linux/cacheinfo.h
+++ b/include/linux/cacheinfo.h
@@ -112,6 +112,7 @@ int acpi_get_cache_info(unsigned int cpu,
#endif
const struct attribute_group *cache_get_priv_group(struct cacheinfo *this_leaf);
+unsigned long cache_of_calculate_id(struct device_node *np);
/*
* Get the cacheinfo structure for the cache associated with @cpu at
--
2.20.1
