linux-kernel - [PATCH 2/2] arm64: kexec: reduce calls to page

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Date:   Sun, 31 Oct 2021 02:32:00 +0800
From:   Rongwei Wang <rongwei.wang@...ux.alibaba.com>
To:     catalin.marinas@....com, will@...nel.org, mark.rutland@....com,
        james.morse@....com, ardb@...nel.org, tabba@...gle.com,
        akpm@...ux-foundation.org, rppt@...nel.org,
        anshuman.khandual@....com
Cc:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH 2/2] arm64: kexec: reduce calls to page_address()

In kexec_page_alloc(), page_address() is called twice.
This patch add a new variable to help to reduce calls
to page_address().

Signed-off-by: Rongwei Wang <rongwei.wang@...ux.alibaba.com>
---
 arch/arm64/kernel/machine_kexec.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
index 1038494135c8..7f2530bcd42e 100644
--- a/arch/arm64/kernel/machine_kexec.c
+++ b/arch/arm64/kernel/machine_kexec.c
@@ -104,13 +104,15 @@ static void *kexec_page_alloc(void *arg)
 {
 	struct kimage *kimage = (struct kimage *)arg;
 	struct page *page = kimage_alloc_control_pages(kimage, 0);
+	void *vaddr = NULL;
 
 	if (!page)
 		return NULL;
 
-	memset(page_address(page), 0, PAGE_SIZE);
+	vaddr = page_address(page);
+	memset(vaddr, 0, PAGE_SIZE);
 
-	return page_address(page);
+	return vaddr;
 }
 
 int machine_kexec_post_load(struct kimage *kimage)
-- 
2.27.0