linux-kernel - [PATCH v2 5/9] x86/clear_page: add clear

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Message-Id: <20230830184958.2333078-6-ankur.a.arora@oracle.com>
Date:   Wed, 30 Aug 2023 11:49:54 -0700
From:   Ankur Arora <ankur.a.arora@...cle.com>
To:     linux-kernel@...r.kernel.org, linux-mm@...ck.org, x86@...nel.org
Cc:     akpm@...ux-foundation.org, luto@...nel.org, bp@...en8.de,
        dave.hansen@...ux.intel.com, hpa@...or.com, mingo@...hat.com,
        juri.lelli@...hat.com, vincent.guittot@...aro.org,
        willy@...radead.org, mgorman@...e.de, peterz@...radead.org,
        rostedt@...dmis.org, tglx@...utronix.de, jon.grimm@....com,
        bharata@....com, raghavendra.kt@....com,
        boris.ostrovsky@...cle.com, konrad.wilk@...cle.com,
        Ankur Arora <ankur.a.arora@...cle.com>
Subject: [PATCH v2 5/9] x86/clear_page: add clear_pages()

Expose multi-page clearing via clear_pages().

Signed-off-by: Ankur Arora <ankur.a.arora@...cle.com>
---
 arch/x86/include/asm/page_64.h | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/page_64.h b/arch/x86/include/asm/page_64.h
index 56f9adf0e892..1e71570ea987 100644
--- a/arch/x86/include/asm/page_64.h
+++ b/arch/x86/include/asm/page_64.h
@@ -43,9 +43,9 @@ void clear_pages_orig(void *page, unsigned int length);
 void clear_pages_rep(void *page, unsigned int length);
 void clear_pages_erms(void *page, unsigned int length);
 
-static inline void clear_page(void *page)
+static inline void clear_pages(void *page, unsigned int nsubpages)
 {
-	unsigned int length = PAGE_SIZE;
+	unsigned int length = nsubpages * PAGE_SIZE;
 	/*
 	 * Clean up KMSAN metadata for the pages being cleared. The assembly call
 	 * below clobbers @page, so we perform unpoisoning before it.
@@ -60,6 +60,11 @@ static inline void clear_page(void *page)
 			   : "cc", "memory", "rax", "rcx");
 }
 
+static inline void clear_page(void *page)
+{
+	clear_pages(page, 1);
+}
+
 void copy_page(void *to, void *from);
 
 #ifdef CONFIG_X86_5LEVEL
-- 
2.31.1