From: Jacob Keller <jacob.e.keller@intel.com>
Date: Mon, 8 Jul 2019 16:12:33 -0700
Subject: fm10k: cast page_addr to u8 * when incrementing it
Patch-mainline: v5.4-rc1
Git-commit: 27429be75e0d291a74b57f9753537e727b7635b7
References: jsc#SLE-8009

The page_addr variable is a void pointer. Incrementing it before calling
prefetch is technically undefined. Fix this by casting it to a u8*
pointer before incrementing it. This ensures that we increment the
pointer value in byte units, instead of relying on this undefined
behavior.

This was detected by cppcheck, and resolves the following warning
produced by that tool:

[fm10k_main.c:328]: (portability) 'page_addr' is of type 'void *'. When
using void pointers in calculations, the behaviour is undefined.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/intel/fm10k/fm10k_main.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/intel/fm10k/fm10k_main.c
+++ b/drivers/net/ethernet/intel/fm10k/fm10k_main.c
@@ -315,7 +315,7 @@ static struct sk_buff *fm10k_fetch_rx_bu
 		/* prefetch first cache line of first page */
 		prefetch(page_addr);
 #if L1_CACHE_BYTES < 128
-		prefetch(page_addr + L1_CACHE_BYTES);
+		prefetch((void *)((u8 *)page_addr + L1_CACHE_BYTES));
 #endif
 
 		/* allocate a skb to store the frags */