linux-kernel - [PATCH 1/3] cacheinfo: Add function to get cacheinfo for a given (cpu, cachelevel)

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240531195720.232561-2-tony.luck@intel.com>
Date: Fri, 31 May 2024 12:57:18 -0700
From: Tony Luck <tony.luck@...el.com>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Borislav Petkov <bp@...en8.de>
Cc: Fenghua Yu <fenghua.yu@...el.com>,
	Reinette Chatre <reinette.chatre@...el.com>,
	Maciej Wieczor-Retman <maciej.wieczor-retman@...el.com>,
	Peter Newman <peternewman@...gle.com>,
	James Morse <james.morse@....com>,
	Babu Moger <babu.moger@....com>,
	Drew Fustini <dfustini@...libre.com>,
	Dave Martin <Dave.Martin@....com>,
	linux-kernel@...r.kernel.org,
	patches@...ts.linux.dev,
	Tony Luck <tony.luck@...el.com>
Subject: [PATCH 1/3] cacheinfo: Add function to get cacheinfo for a given (cpu, cachelevel)

Resctrl code open codes a search for information about a given cache
level in a couple of places (and more are on the way).

Provide a new inline function get_cpu_cacheinfo_level() in
<linux/cacheinfo.h> to do the search and return a pointer to
the cacheinfo structure.

Simplify the existing get_cpu_cacheinfo_id() by using this new
function to do the search.

Signed-off-by: Tony Luck <tony.luck@...el.com>
---
 include/linux/cacheinfo.h | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/include/linux/cacheinfo.h b/include/linux/cacheinfo.h
index 2cb15fe4fe12..301b0b24f446 100644
--- a/include/linux/cacheinfo.h
+++ b/include/linux/cacheinfo.h
@@ -113,10 +113,10 @@ int acpi_get_cache_info(unsigned int cpu,
 const struct attribute_group *cache_get_priv_group(struct cacheinfo *this_leaf);
 
 /*
- * Get the id of the cache associated with @cpu at level @level.
+ * Get the cacheinfo structure for cache associated with @cpu at level @level.
  * cpuhp lock must be held.
  */
-static inline int get_cpu_cacheinfo_id(int cpu, int level)
+static inline struct cacheinfo *get_cpu_cacheinfo_level(int cpu, int level)
 {
 	struct cpu_cacheinfo *ci = get_cpu_cacheinfo(cpu);
 	int i;
@@ -124,12 +124,23 @@ static inline int get_cpu_cacheinfo_id(int cpu, int level)
 	for (i = 0; i < ci->num_leaves; i++) {
 		if (ci->info_list[i].level == level) {
 			if (ci->info_list[i].attributes & CACHE_ID)
-				return ci->info_list[i].id;
-			return -1;
+				return &ci->info_list[i];
+			return NULL;
 		}
 	}
 
-	return -1;
+	return NULL;
+}
+
+/*
+ * Get the id of the cache associated with @cpu at level @level.
+ * cpuhp lock must be held.
+ */
+static inline int get_cpu_cacheinfo_id(int cpu, int level)
+{
+	struct cacheinfo *ci = get_cpu_cacheinfo_level(cpu, level);
+
+	return ci ? ci->id : -1;
 }
 
 #ifdef CONFIG_ARM64
-- 
2.45.0