linux-kernel - [patch V2 10/16] x86/tlb: Move __flush_tlb

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Date:   Tue, 21 Apr 2020 11:20:37 +0200
From:   Thomas Gleixner <tglx@...utronix.de>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     x86@...nel.org, Christoph Hellwig <hch@....de>,
        Kees Cook <keescook@...omium.org>,
        Alexandre Chartre <alexandre.chartre@...cle.com>,
        "Peter Zijlstra (Intel)" <peterz@...radead.org>,
        Thomas Lendacky <Thomas.Lendacky@....com>,
        Juergen Gross <jgross@...e.com>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>
Subject: [patch V2 10/16] x86/tlb: Move __flush_tlb_all() out of line

Reduces the number of required exports to one and makes flush_tlb_global()
static to the TLB code.

flush_tlb_local() cannot be confined to the tlb code as the mtrr handling
requires a PGE-less flush.

Suggested-by: Christoph Hellwig <hch@....de>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
V2: New patch
---
 arch/x86/include/asm/tlbflush.h |   23 +----------------------
 arch/x86/mm/tlb.c               |   29 ++++++++++++++++++++++-------
 2 files changed, 23 insertions(+), 29 deletions(-)

--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -142,8 +142,8 @@ static inline unsigned long build_cr3_no
 
 struct flush_tlb_info;
 
+void __flush_tlb_all(void);
 void flush_tlb_local(void);
-void flush_tlb_global(void);
 void flush_tlb_one_user(unsigned long addr);
 void flush_tlb_one_kernel(unsigned long addr);
 void flush_tlb_others(const struct cpumask *cpumask,
@@ -341,27 +341,6 @@ static inline void cr4_set_bits_and_upda
 
 extern void initialize_tlbstate_and_flush(void);
 
-/*
- * flush everything
- */
-static inline void __flush_tlb_all(void)
-{
-	/*
-	 * This is to catch users with enabled preemption and the PGE feature
-	 * and don't trigger the warning in __native_flush_tlb().
-	 */
-	VM_WARN_ON_ONCE(preemptible());
-
-	if (boot_cpu_has(X86_FEATURE_PGE)) {
-		flush_tlb_global();
-	} else {
-		/*
-		 * !PGE -> !PCID (setup_pcid()), thus every flush is total.
-		 */
-		flush_tlb_local();
-	}
-}
-
 #define TLB_FLUSH_ALL	-1UL
 
 /*
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -1018,12 +1018,6 @@ STATIC_NOPV void native_flush_tlb_global
 	raw_local_irq_restore(flags);
 }
 
-void flush_tlb_global(void)
-{
-	__flush_tlb_global();
-}
-EXPORT_SYMBOL_GPL(flush_tlb_global);
-
 /*
  * Flush the entire current user mapping
  */
@@ -1046,7 +1040,28 @@ void flush_tlb_local(void)
 {
 	__flush_tlb_local();
 }
-EXPORT_SYMBOL_GPL(flush_tlb_local);
+
+/*
+ * Flush everything
+ */
+void __flush_tlb_all(void)
+{
+	/*
+	 * This is to catch users with enabled preemption and the PGE feature
+	 * and don't trigger the warning in __native_flush_tlb().
+	 */
+	VM_WARN_ON_ONCE(preemptible());
+
+	if (boot_cpu_has(X86_FEATURE_PGE)) {
+		__flush_tlb_global();
+	} else {
+		/*
+		 * !PGE -> !PCID (setup_pcid()), thus every flush is total.
+		 */
+		flush_tlb_local();
+	}
+}
+EXPORT_SYMBOL_GPL(__flush_tlb_all);
 
 /*
  * arch_tlbbatch_flush() performs a full TLB flush regardless of the active mm.