From: Julia Lawall <julia@diku.dk>
Date: Sun, 23 Nov 2008 10:46:58 +0000 (+0100)
Subject: arch/avr32: Eliminate NULL test and memset after alloc_bootmem
X-Git-Tag: v2.6.29-rc1~192^2~1^3
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=e24500193bc39ef197d9f96af5850e7345fed84d;p=linux-2.6-omap-h63xx.git

arch/avr32: Eliminate NULL test and memset after alloc_bootmem

As noted by Akinobu Mita in patch b1fceac2b9e04d278316b2faddf276015fc06e3b,
alloc_bootmem and related functions never return NULL and always return a
zeroed region of memory.  Thus a NULL test or memset after calls to these
functions is unnecessary.

This was fixed using the following semantic patch.
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
expression E;
statement S;
@@

E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\|alloc_bootmem_node\|alloc_bootmem_low_pages_node\|alloc_bootmem_pages_node\)(...)
... when != E
(
- BUG_ON (E == NULL);
|
- if (E == NULL) S
)

@@
expression E,E1;
@@

E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\|alloc_bootmem_node\|alloc_bootmem_low_pages_node\|alloc_bootmem_pages_node\)(...)
... when != E
- memset(E,0,E1);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
---

diff --git a/arch/avr32/mm/init.c b/arch/avr32/mm/init.c
index fa92ff6d95f..e819fa69a90 100644
--- a/arch/avr32/mm/init.c
+++ b/arch/avr32/mm/init.c
@@ -97,7 +97,6 @@ void __init paging_init(void)
 
 	mem_map = NODE_DATA(0)->node_mem_map;
 
-	memset(zero_page, 0, PAGE_SIZE);
 	empty_zero_page = virt_to_page(zero_page);
 	flush_dcache_page(empty_zero_page);
 }