[added,to,the,4.1,stable,tree] drivers: base: cacheinfo: fix x86 with CONFIG_OF enabled

Message ID 20180301152116.1486-210-alexander.levin@microsoft.com
State New
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  • [added,to,the,4.1,stable,tree] drivers: base: cacheinfo: fix x86 with CONFIG_OF enabled
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Commit Message

Sasha Levin March 1, 2018, 3:24 p.m.
From: Sudeep Holla <sudeep.holla@arm.com>

This patch has been added to the 4.1 stable tree. If you have any
objections, please let us know.




[ Upstream commit fac51482577d5e05bbb0efa8d602a3c2111098bf ]

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@linuxfoundation.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
 arch/x86/kernel/cpu/intel_cacheinfo.c | 2 ++
 drivers/base/cacheinfo.c              | 3 +++
 include/linux/cacheinfo.h             | 1 +
 3 files changed, 6 insertions(+)

diff --git a/arch/x86/kernel/cpu/intel_cacheinfo.c b/arch/x86/kernel/cpu/intel_cacheinfo.c
index edcb0e28c336..13fb13334f2a 100644
--- 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(unsigned int cpu)
 		ci_leaf_init(this_leaf++, &id4_regs);
 		__cache_cpumap_setup(cpu, idx, &id4_regs);
+	this_cpu_ci->cpu_map_populated = true;
 	return 0;
diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index fdba441457ec..3f5fb95b0f4c 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -106,6 +106,9 @@  static int cache_shared_cpu_map_setup(unsigned int cpu)
 	unsigned int index;
 	int ret;
+	if (this_cpu_ci->cpu_map_populated)
+		return 0;
 	ret = cache_setup_of_node(cpu);
 	if (ret)
 		return ret;
diff --git a/include/linux/cacheinfo.h b/include/linux/cacheinfo.h
index 3daf5ed392c9..4b97ae264388 100644
--- 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;