diff mbox series

[v2,1/2] x86, lib: Add WBNOINVD helper functions

Message ID 20250109225533.1841097-2-kevinloughlin@google.com (mailing list archive)
State New
Headers show
Series KVM: SEV: Prefer WBNOINVD over WBINVD for cache maintenance efficiency | expand

Commit Message

Kevin Loughlin Jan. 9, 2025, 10:55 p.m. UTC
In line with WBINVD usage, add WBONINVD helper functions.

Signed-off-by: Kevin Loughlin <kevinloughlin@google.com>
---
 arch/x86/include/asm/smp.h           |  7 +++++++
 arch/x86/include/asm/special_insns.h |  7 ++++++-
 arch/x86/lib/cache-smp.c             | 12 ++++++++++++
 3 files changed, 25 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index ca073f40698f..ecf93a243b83 100644
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -112,6 +112,7 @@  void native_play_dead(void);
 void play_dead_common(void);
 void wbinvd_on_cpu(int cpu);
 int wbinvd_on_all_cpus(void);
+int wbnoinvd_on_all_cpus(void);
 
 void smp_kick_mwait_play_dead(void);
 
@@ -160,6 +161,12 @@  static inline int wbinvd_on_all_cpus(void)
 	return 0;
 }
 
+static inline int wbnoinvd_on_all_cpus(void)
+{
+	wbnoinvd();
+	return 0;
+}
+
 static inline struct cpumask *cpu_llc_shared_mask(int cpu)
 {
 	return (struct cpumask *)cpumask_of(0);
diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h
index fab7c8af27a4..3db7bf86f81f 100644
--- a/arch/x86/include/asm/special_insns.h
+++ b/arch/x86/include/asm/special_insns.h
@@ -117,7 +117,12 @@  static inline void wrpkru(u32 pkru)
 
 static __always_inline void wbinvd(void)
 {
-	asm volatile("wbinvd": : :"memory");
+	asm volatile("wbinvd" : : : "memory");
+}
+
+static __always_inline void wbnoinvd(void)
+{
+	asm volatile("wbnoinvd" : : : "memory");
 }
 
 static inline unsigned long __read_cr4(void)
diff --git a/arch/x86/lib/cache-smp.c b/arch/x86/lib/cache-smp.c
index 7af743bd3b13..7ac5cca53031 100644
--- a/arch/x86/lib/cache-smp.c
+++ b/arch/x86/lib/cache-smp.c
@@ -20,3 +20,15 @@  int wbinvd_on_all_cpus(void)
 	return 0;
 }
 EXPORT_SYMBOL(wbinvd_on_all_cpus);
+
+static void __wbnoinvd(void *dummy)
+{
+	wbnoinvd();
+}
+
+int wbnoinvd_on_all_cpus(void)
+{
+	on_each_cpu(__wbnoinvd, NULL, 1);
+	return 0;
+}
+EXPORT_SYMBOL(wbnoinvd_on_all_cpus);