[PATCH 5/9] x86/clear_pages: add clear_pages()

[Ankur Arora]

Add clear_pages() and define the ancillary clear_user_pages().

Signed-off-by: Ankur Arora <ankur.a.arora@xxxxxxxxxx>
---
 arch/x86/include/asm/page.h    | 6 ++++++
 arch/x86/include/asm/page_32.h | 6 ++++++
 arch/x86/include/asm/page_64.h | 9 +++++++--
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h
index d18e5c332cb9..03e3c69fc427 100644
--- a/arch/x86/include/asm/page.h
+++ b/arch/x86/include/asm/page.h
@@ -28,6 +28,12 @@ static inline void clear_user_page(void *page, unsigned long vaddr,
 	clear_page(page);
 }
 
+static inline void clear_user_pages(void *page, unsigned long vaddr,
+				    struct page *pg, unsigned int nsubpages)
+{
+	clear_pages(page, nsubpages);
+}
+
 static inline void copy_user_page(void *to, void *from, unsigned long vaddr,
 				  struct page *topage)
 {
diff --git a/arch/x86/include/asm/page_32.h b/arch/x86/include/asm/page_32.h
index 580d71aca65a..3523d1150cfc 100644
--- a/arch/x86/include/asm/page_32.h
+++ b/arch/x86/include/asm/page_32.h
@@ -22,6 +22,12 @@ static inline void clear_page(void *page)
 	memset(page, 0, PAGE_SIZE);
 }
 
+static inline void clear_pages(void *page, unsigned int nsubpages)
+{
+	for (int i = 0; i < nsubpages; i++)
+		clear_page(page + i * PAGE_SIZE);
+}
+
 static inline void copy_page(void *to, void *from)
 {
 	memcpy(to, from, PAGE_SIZE);
diff --git a/arch/x86/include/asm/page_64.h b/arch/x86/include/asm/page_64.h
index 7ca3bd2448c1..42f6c45206c1 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 long length = PAGE_SIZE;
+	unsigned int length = nsubpages * PAGE_SIZE;
 	/*
 	 * Clean up KMSAN metadata for the page 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