--- /dev/null
+From 5c2712387d4850e0b64121d5fd3e6c4e84ea3266 Mon Sep 17 00:00:00 2001
+From: Yicong Yang <yangyicong@hisilicon.com>
+Date: Tue, 28 Mar 2023 19:49:15 +0800
+Subject: cacheinfo: Fix LLC is not exported through sysfs
+
+From: Yicong Yang <yangyicong@hisilicon.com>
+
+commit 5c2712387d4850e0b64121d5fd3e6c4e84ea3266 upstream.
+
+After entering 6.3-rc1 the LLC cacheinfo is not exported on our ACPI
+based arm64 server. This is because the LLC cacheinfo is partly reset
+when secondary CPUs boot up. On arm64 the primary cpu will allocate
+and setup cacheinfo:
+init_cpu_topology()
+ for_each_possible_cpu()
+ fetch_cache_info() // Allocate cacheinfo and init levels
+detect_cache_attributes()
+ cache_shared_cpu_map_setup()
+ if (!last_level_cache_is_valid()) // not valid, setup LLC
+ cache_setup_properties() // setup LLC
+
+On secondary CPU boot up:
+detect_cache_attributes()
+ populate_cache_leaves()
+ get_cache_type() // Get cache type from clidr_el1,
+ // for LLC type=CACHE_TYPE_NOCACHE
+ cache_shared_cpu_map_setup()
+ if (!last_level_cache_is_valid()) // Valid and won't go to this branch,
+ // leave LLC's type=CACHE_TYPE_NOCACHE
+
+The last_level_cache_is_valid() use cacheinfo->{attributes, fw_token} to
+test it's valid or not, but populate_cache_leaves() will only reset
+LLC's type, so we won't try to re-setup LLC's type and leave it
+CACHE_TYPE_NOCACHE and won't export it through sysfs.
+
+This patch tries to fix this by not re-populating the cache leaves if
+the LLC is valid.
+
+Fixes: 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU")
+Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
+Reviewed-by: Pierre Gondois <pierre.gondois@arm.com>
+Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
+Link: https://lore.kernel.org/r/20230328114915.33340-1-yangyicong@huawei.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/base/cacheinfo.c | 16 +++++++++++-----
+ 1 file changed, 11 insertions(+), 5 deletions(-)
+
+--- a/drivers/base/cacheinfo.c
++++ b/drivers/base/cacheinfo.c
+@@ -490,12 +490,18 @@ int detect_cache_attributes(unsigned int
+
+ populate_leaves:
+ /*
+- * populate_cache_leaves() may completely setup the cache leaves and
+- * shared_cpu_map or it may leave it partially setup.
++ * If LLC is valid the cache leaves were already populated so just go to
++ * update the cpu map.
+ */
+- ret = populate_cache_leaves(cpu);
+- if (ret)
+- goto free_ci;
++ if (!last_level_cache_is_valid(cpu)) {
++ /*
++ * populate_cache_leaves() may completely setup the cache leaves and
++ * shared_cpu_map or it may leave it partially setup.
++ */
++ ret = populate_cache_leaves(cpu);
++ if (ret)
++ goto free_ci;
++ }
+
+ /*
+ * For systems using DT for cache hierarchy, fw_token
--- /dev/null
+From ecaef469920fd6d2c7687f19081946f47684a423 Mon Sep 17 00:00:00 2001
+From: Pierre Gondois <pierre.gondois@arm.com>
+Date: Tue, 24 Jan 2023 16:40:46 +0100
+Subject: cacheinfo: Initialize variables in fetch_cache_info()
+
+From: Pierre Gondois <pierre.gondois@arm.com>
+
+commit ecaef469920fd6d2c7687f19081946f47684a423 upstream.
+
+Set potentially uninitialized variables to 0. This is particularly
+relevant when CONFIG_ACPI_PPTT is not set.
+
+Reported-by: kernel test robot <lkp@intel.com>
+Link: https://lore.kernel.org/all/202301052307.JYt1GWaJ-lkp@intel.com/
+Reported-by: Dan Carpenter <error27@gmail.com>
+Link: https://lore.kernel.org/all/Y86iruJPuwNN7rZw@kili/
+Fixes: 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU")
+Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
+Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
+Link: https://lore.kernel.org/r/20230124154053.355376-2-pierre.gondois@arm.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/base/cacheinfo.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/base/cacheinfo.c
++++ b/drivers/base/cacheinfo.c
+@@ -440,7 +440,7 @@ int allocate_cache_info(int cpu)
+ int fetch_cache_info(unsigned int cpu)
+ {
+ struct cpu_cacheinfo *this_cpu_ci;
+- unsigned int levels, split_levels;
++ unsigned int levels = 0, split_levels = 0;
+ int ret;
+
+ if (acpi_disabled) {
--- /dev/null
+From c26fabe73330d983c7ce822c6b6ec0879b4da61f Mon Sep 17 00:00:00 2001
+From: K Prateek Nayak <kprateek.nayak@amd.com>
+Date: Mon, 8 May 2023 14:11:15 +0530
+Subject: drivers: base: cacheinfo: Update cpu_map_populated during CPU Hotplug
+
+From: K Prateek Nayak <kprateek.nayak@amd.com>
+
+commit c26fabe73330d983c7ce822c6b6ec0879b4da61f upstream.
+
+Until commit 5c2712387d48 ("cacheinfo: Fix LLC is not exported through
+sysfs"), cacheinfo called populate_cache_leaves() for CPU coming online
+which let the arch specific functions handle (at least on x86)
+populating the shared_cpu_map. However, with the changes in the
+aforementioned commit, populate_cache_leaves() is not called when a CPU
+comes online as a result of hotplug since last_level_cache_is_valid()
+returns true as the cacheinfo data is not discarded. The CPU coming
+online is not present in shared_cpu_map, however, it will not be added
+since the cpu_cacheinfo->cpu_map_populated flag is set (it is set in
+populate_cache_leaves() when cacheinfo is first populated for x86)
+
+This can lead to inconsistencies in the shared_cpu_map when an offlined
+CPU comes online again. Example below depicts the inconsistency in the
+shared_cpu_list in cacheinfo when CPU8 is offlined and onlined again on
+a 3rd Generation EPYC processor:
+
+ # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done
+ /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8,136
+ /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8,136
+ /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8,136
+ /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8-15,136-143
+
+ # echo 0 > /sys/devices/system/cpu/cpu8/online
+ # echo 1 > /sys/devices/system/cpu/cpu8/online
+
+ # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done
+ /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8
+ /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8
+ /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8
+ /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8
+
+ # cat /sys/devices/system/cpu/cpu136/cache/index0/shared_cpu_list
+ 136
+
+ # cat /sys/devices/system/cpu/cpu136/cache/index3/shared_cpu_list
+ 9-15,136-143
+
+Clear the flag when the CPU is removed from shared_cpu_map when
+cache_shared_cpu_map_remove() is called during CPU hotplug. This will
+allow cache_shared_cpu_map_setup() to add the CPU coming back online in
+the shared_cpu_map. Set the flag again when the shared_cpu_map is setup.
+Following are results of performing the same test as described above with
+the changes:
+
+ # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done
+ /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8,136
+ /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8,136
+ /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8,136
+ /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8-15,136-143
+
+ # echo 0 > /sys/devices/system/cpu/cpu8/online
+ # echo 1 > /sys/devices/system/cpu/cpu8/online
+
+ # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done
+ /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8,136
+ /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8,136
+ /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8,136
+ /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8-15,136-143
+
+ # cat /sys/devices/system/cpu/cpu136/cache/index0/shared_cpu_list
+ 8,136
+
+ # cat /sys/devices/system/cpu/cpu136/cache/index3/shared_cpu_list
+ 8-15,136-143
+
+Fixes: 5c2712387d48 ("cacheinfo: Fix LLC is not exported through sysfs")
+Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
+Reviewed-by: Yicong Yang <yangyicong@hisilicon.com>
+Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
+Link: https://lore.kernel.org/r/20230508084115.1157-3-kprateek.nayak@amd.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/base/cacheinfo.c | 6 ++++++
+ 1 file changed, 6 insertions(+)
+
+--- a/drivers/base/cacheinfo.c
++++ b/drivers/base/cacheinfo.c
+@@ -365,11 +365,14 @@ static int cache_shared_cpu_map_setup(un
+ coherency_max_size = this_leaf->coherency_line_size;
+ }
+
++ /* shared_cpu_map is now populated for the cpu */
++ this_cpu_ci->cpu_map_populated = true;
+ return 0;
+ }
+
+ static void cache_shared_cpu_map_remove(unsigned int cpu)
+ {
++ struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
+ struct cacheinfo *this_leaf, *sib_leaf;
+ unsigned int sibling, index, sib_index;
+
+@@ -404,6 +407,9 @@ static void cache_shared_cpu_map_remove(
+ if (of_have_populated_dt())
+ of_node_put(this_leaf->fw_token);
+ }
++
++ /* cpu is no longer populated in the shared map */
++ this_cpu_ci->cpu_map_populated = false;
+ }
+
+ static void free_cache_attributes(unsigned int cpu)
projects / thirdparty / kernel / stable-queue.git / commitdiff
