4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sudeep Holla <sudeep.holla@xxxxxxx>
commit fac51482577d5e05bbb0efa8d602a3c2111098bf upstream.
With CONFIG_OF enabled on x86, we get the following error on boot:
"
Failed to find cpu0 device node
Unable to detect cache hierarchy from DT for CPU 0
"
and the cacheinfo fails to get populated in the corresponding sysfs
entries. This is because cache_setup_of_node looks for of_node for
setting up the shared cpu_map without checking that it's already
populated in the architecture specific callback.
In order to indicate that the shared cpu_map is already populated, this
patch introduces a boolean `cpu_map_populated` in struct cpu_cacheinfo
that can be used by the generic code to skip cache_shared_cpu_map_setup.
This patch also sets that boolean for x86.
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/intel_cacheinfo.c | 2 ++
drivers/base/cacheinfo.c | 3 +++
include/linux/cacheinfo.h | 1 +
3 files changed, 6 insertions(+)
--- a/arch/x86/kernel/cpu/intel_cacheinfo.c
+++ b/arch/x86/kernel/cpu/intel_cacheinfo.c
@@ -934,6 +934,8 @@ static int __populate_cache_leaves(unsig
ci_leaf_init(this_leaf++, &id4_regs);
__cache_cpumap_setup(cpu, idx, &id4_regs);
}
+ this_cpu_ci->cpu_map_populated = true;
+
return 0;
}
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -106,6 +106,9 @@ static int cache_shared_cpu_map_setup(un
unsigned int index;
int ret;
+ if (this_cpu_ci->cpu_map_populated)
+ return 0;
+
ret = cache_setup_of_node(cpu);
if (ret)
return ret;
--- a/include/linux/cacheinfo.h
+++ b/include/linux/cacheinfo.h
@@ -71,6 +71,7 @@ struct cpu_cacheinfo {
struct cacheinfo *info_list;
unsigned int num_levels;
unsigned int num_leaves;
+ bool cpu_map_populated;
};
/*