From: Sudeep Holla <sudeep.holla@arm.com>
To: linux-kernel@vger.kernel.org, Greg KH <gregkh@linuxfoundation.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>,
Atish Patra <atishp@atishpatra.org>,
Atish Patra <atishp@rivosinc.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Qing Wang <wangqing@vivo.com>, Rob Herring <robh+dt@kernel.org>,
"Rafael J . Wysocki" <rafael@kernel.org>,
Ionela Voinescu <ionela.voinescu@arm.com>,
Pierre Gondois <pierre.gondois@arm.com>,
linux-arm-kernel@lists.infradead.org,
linux-riscv@lists.infradead.org, Gavin Shan <gshan@redhat.com>
Subject: [PATCH v4 05/20] cacheinfo: Add support to check if last level cache(LLC) is valid or shared
Date: Tue, 21 Jun 2022 20:20:19 +0100 [thread overview]
Message-ID: <20220621192034.3332546-6-sudeep.holla@arm.com> (raw)
In-Reply-To: <20220621192034.3332546-1-sudeep.holla@arm.com>
It is useful to have helper to check if the given two CPUs share last level
cache. We can do that check by comparing fw_token or by comparing the cache
ID. Currently we check just for fw_token as the cache ID is optional.
This helper can be used to build the llc_sibling during arch specific
topology parsing and feeding information to the sched_domains. This also
helps to get rid of llc_id in the CPU topology as it is sort of duplicate
information.
Also add helper to check if the llc information in cacheinfo is valid or not.
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
drivers/base/cacheinfo.c | 26 ++++++++++++++++++++++++++
include/linux/cacheinfo.h | 2 ++
2 files changed, 28 insertions(+)
diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index 2cea9201f31c..fdc1baa342f1 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -47,6 +47,32 @@ static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
return sib_leaf->fw_token == this_leaf->fw_token;
}
+bool last_level_cache_is_valid(unsigned int cpu)
+{
+ struct cacheinfo *llc;
+
+ if (!cache_leaves(cpu))
+ return false;
+
+ llc = per_cpu_cacheinfo_idx(cpu, cache_leaves(cpu) - 1);
+
+ return !!llc->fw_token;
+}
+
+bool last_level_cache_is_shared(unsigned int cpu_x, unsigned int cpu_y)
+{
+ struct cacheinfo *llc_x, *llc_y;
+
+ if (!last_level_cache_is_valid(cpu_x) ||
+ !last_level_cache_is_valid(cpu_y))
+ return false;
+
+ llc_x = per_cpu_cacheinfo_idx(cpu_x, cache_leaves(cpu_x) - 1);
+ llc_y = per_cpu_cacheinfo_idx(cpu_y, cache_leaves(cpu_y) - 1);
+
+ return cache_leaves_are_shared(llc_x, llc_y);
+}
+
#ifdef CONFIG_OF
/* OF properties to query for a given cache type */
struct cache_type_info {
diff --git a/include/linux/cacheinfo.h b/include/linux/cacheinfo.h
index 4ff37cb763ae..7e429bc5c1a4 100644
--- a/include/linux/cacheinfo.h
+++ b/include/linux/cacheinfo.h
@@ -82,6 +82,8 @@ struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu);
int init_cache_level(unsigned int cpu);
int populate_cache_leaves(unsigned int cpu);
int cache_setup_acpi(unsigned int cpu);
+bool last_level_cache_is_valid(unsigned int cpu);
+bool last_level_cache_is_shared(unsigned int cpu_x, unsigned int cpu_y);
#ifndef CONFIG_ACPI_PPTT
/*
* acpi_find_last_cache_level is only called on ACPI enabled
--
2.36.1
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next prev parent reply other threads:[~2022-06-21 19:22 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-21 19:20 [PATCH v4 00/20] arch_topology: Updates to add socket support and fix cluster ids Sudeep Holla
2022-06-21 19:20 ` [PATCH v4 01/20] ACPI: PPTT: Use table offset as fw_token instead of virtual address Sudeep Holla
2022-06-22 11:47 ` Rafael J. Wysocki
2022-06-27 13:41 ` Ionela Voinescu
2022-06-21 19:20 ` [PATCH v4 02/20] cacheinfo: Use of_cpu_device_node_get instead cpu_dev->of_node Sudeep Holla
2022-06-21 19:20 ` [PATCH v4 03/20] cacheinfo: Add helper to access any cache index for a given CPU Sudeep Holla
2022-06-21 19:20 ` [PATCH v4 04/20] cacheinfo: Move cache_leaves_are_shared out of CONFIG_OF Sudeep Holla
2022-06-21 19:20 ` Sudeep Holla [this message]
2022-06-21 19:20 ` [PATCH v4 06/20] cacheinfo: Allow early detection and population of cache attributes Sudeep Holla
2022-06-21 19:20 ` [PATCH v4 07/20] cacheinfo: Use cache identifiers to check if the caches are shared if available Sudeep Holla
2022-06-21 19:20 ` [PATCH v4 08/20] arch_topology: Add support to parse and detect cache attributes Sudeep Holla
2022-06-21 19:20 ` [PATCH v4 09/20] arch_topology: Use the last level cache information from the cacheinfo Sudeep Holla
2022-06-21 19:20 ` [PATCH v4 10/20] arm64: topology: Remove redundant setting of llc_id in CPU topology Sudeep Holla
2022-06-23 15:55 ` Catalin Marinas
2022-06-21 19:20 ` [PATCH v4 11/20] arch_topology: Drop LLC identifier stash from the " Sudeep Holla
2022-06-21 19:20 ` [PATCH v4 12/20] arch_topology: Set thread sibling cpumask only within the cluster Sudeep Holla
2022-06-27 13:42 ` Ionela Voinescu
2022-06-21 19:20 ` [PATCH v4 13/20] arch_topology: Check for non-negative value rather than -1 for IDs validity Sudeep Holla
2022-06-21 19:20 ` [PATCH v4 14/20] arch_topology: Avoid parsing through all the CPUs once a outlier CPU is found Sudeep Holla
2022-06-21 19:20 ` [PATCH v4 15/20] arch_topology: Don't set cluster identifier as physical package identifier Sudeep Holla
2022-06-27 13:43 ` Ionela Voinescu
2022-06-21 19:20 ` [PATCH v4 16/20] arch_topology: Drop unnecessary check for uninitialised package_id Sudeep Holla
2022-06-27 13:12 ` Ionela Voinescu
2022-06-27 16:30 ` Sudeep Holla
2022-06-21 19:20 ` [PATCH v4 17/20] arch_topology: Limit span of cpu_clustergroup_mask() Sudeep Holla
2022-06-21 19:20 ` [PATCH v4 18/20] arch_topology: Set cluster identifier in each core/thread from /cpu-map Sudeep Holla
2022-06-27 13:47 ` Ionela Voinescu
2022-06-21 19:20 ` [PATCH v4 19/20] arch_topology: Add support for parsing sockets in /cpu-map Sudeep Holla
2022-06-27 13:47 ` Ionela Voinescu
2022-06-21 19:20 ` [PATCH v4 20/20] arch_topology: Warn that topology for nested clusters is not supported Sudeep Holla
2022-06-22 15:06 ` Ionela Voinescu
2022-06-22 15:46 ` Sudeep Holla
2022-06-27 13:54 ` [PATCH v4 00/20] arch_topology: Updates to add socket support and fix cluster ids Ionela Voinescu
2022-06-27 16:22 ` Sudeep Holla
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