linux-kernel - [tip:x86/mm] x86/mm/cpa: Move CLFLUSH test into cpa_flush

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Date:   Thu, 27 Sep 2018 11:54:48 -0700
From:   tip-bot for Peter Zijlstra <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     mingo@...nel.org, peterz@...radead.org, tglx@...utronix.de,
        bin.yang@...el.com, linux-kernel@...r.kernel.org, hpa@...or.com,
        mark.gross@...el.com, dave.hansen@...el.com
Subject: [tip:x86/mm] x86/mm/cpa: Move CLFLUSH test into cpa_flush_array()

Commit-ID:  fce2ce9544e9f098ba828442221ce99c2a5ecb0f
Gitweb:     https://git.kernel.org/tip/fce2ce9544e9f098ba828442221ce99c2a5ecb0f
Author:     Peter Zijlstra <peterz@...radead.org>
AuthorDate: Wed, 19 Sep 2018 10:50:22 +0200
Committer:  Thomas Gleixner <tglx@...utronix.de>
CommitDate: Thu, 27 Sep 2018 20:39:42 +0200

x86/mm/cpa: Move CLFLUSH test into cpa_flush_array()

Rather than guarding cpa_flush_array() users with a CLFLUSH test, put
it inside.

Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Reviewed-by: Dave Hansen <dave.hansen@...el.com>
Cc: Bin Yang <bin.yang@...el.com>
Cc: Mark Gross <mark.gross@...el.com>
Link: https://lkml.kernel.org/r/20180919085948.087848187@infradead.org

---
 arch/x86/mm/pageattr.c | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 3cc4a2ae4dbb..33d89d505f93 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -328,6 +328,11 @@ static void cpa_flush_array(unsigned long baddr, unsigned long *start,
 
 	BUG_ON(irqs_disabled() && !early_boot_irqs_disabled);
 
+	if (!static_cpu_has(X86_FEATURE_CLFLUSH)) {
+		cpa_flush_all(cache);
+		return;
+	}
+
 	flush_tlb_kernel_range(baddr, baddr + PAGE_SIZE * numpages);
 
 	if (!cache)
@@ -1756,19 +1761,19 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages,
 	cache = !!pgprot2cachemode(mask_set);
 
 	/*
-	 * On success we use CLFLUSH, when the CPU supports it to
-	 * avoid the WBINVD. If the CPU does not support it and in the
-	 * error case we fall back to cpa_flush_all (which uses
-	 * WBINVD):
+	 * On error; flush everything to be sure.
 	 */
-	if (!ret && boot_cpu_has(X86_FEATURE_CLFLUSH)) {
-		if (cpa.flags & (CPA_PAGES_ARRAY | CPA_ARRAY)) {
-			cpa_flush_array(baddr, addr, numpages, cache,
-					cpa.flags, pages);
-		} else
-			cpa_flush_range(baddr, numpages, cache);
-	} else
+	if (ret) {
 		cpa_flush_all(cache);
+		goto out;
+	}
+
+	if (cpa.flags & (CPA_PAGES_ARRAY | CPA_ARRAY)) {
+		cpa_flush_array(baddr, addr, numpages, cache,
+				cpa.flags, pages);
+	} else {
+		cpa_flush_range(baddr, numpages, cache);
+	}
 
 out:
 	return ret;