From 792adb90fa724ce07c0171cbc96b9215af4b1045 Mon Sep 17 00:00:00 2001
From: Vlastimil Babka <vbabka@suse.cz>
Date: Tue, 14 Aug 2018 20:50:47 +0200
Subject: [PATCH] x86/init: fix build with CONFIG_SWAP=n
Git-commit: 792adb90fa724ce07c0171cbc96b9215af4b1045
Patch-mainline: v4.19-rc1
References: bnc#1106121

The introduction of generic_max_swapfile_size and arch-specific versions has
broken linking on x86 with CONFIG_SWAP=n due to undefined reference to
'generic_max_swapfile_size'. Fix it by compiling the x86-specific
max_swapfile_size() only with CONFIG_SWAP=y.

Reported-by: Tomas Pruzina <pruzinat@gmail.com>
Fixes: 377eeaa8e11f ("x86/speculation/l1tf: Limit swap file size to MAX_PA/2")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>

---
 arch/x86/mm/init.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 156ed8154af8..acfab322fbe0 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -914,6 +914,7 @@ void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache)
 	__pte2cachemode_tbl[entry] = cache;
 }
 
+#ifdef CONFIG_SWAP
 unsigned long max_swapfile_size(void)
 {
 	unsigned long pages;
@@ -934,3 +935,4 @@ unsigned long max_swapfile_size(void)
 	}
 	return pages;
 }
+#endif
-- 
1.8.5.6