From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jungseok Lee Subject: [PATCH] swiotlb: Correct kernel command line handler Date: Tue, 01 Apr 2014 10:51:58 +0900 Message-ID: <011801cf4d4c$f7ba51f0$e72ef5d0$@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from mailout4.samsung.com ([203.254.224.34]:38714 "EHLO mailout4.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751098AbaDABwA (ORCPT ); Mon, 31 Mar 2014 21:52:00 -0400 Content-language: ko Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: konrad.wilk@oracle.com, linux-kernel@vger.kernel.org Cc: sungjinn.chung@samsung.com, linux-samsung-soc This patch corrects kernel command line handler when io_tlb_nslabs is set to 0. A current implementation allocates default size memory (64MB) when 0 is given to io_tlb_nslabs ("swiotlb=0") by kernel command line. In other words, memory is allocated unintentionally. Signed-off-by: Jungseok Lee Signed-off-by: Sungjinn Chung --- lib/swiotlb.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/lib/swiotlb.c b/lib/swiotlb.c index b604b83..9fe9f71 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -55,6 +55,8 @@ int swiotlb_force; +static int swiotlb_no_use; + /* * Used to do a quick range check in swiotlb_tbl_unmap_single and * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this @@ -102,6 +104,8 @@ setup_io_tlb_npages(char *str) io_tlb_nslabs = simple_strtoul(str, &str, 0); /* avoid tail segment of size < IO_TLB_SEGSIZE */ io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); + if (!io_tlb_nslabs) + swiotlb_no_use = 1; } if (*str == ',') ++str; @@ -212,7 +216,7 @@ swiotlb_init(int verbose) unsigned char *vstart; unsigned long bytes; - if (!io_tlb_nslabs) { + if (!swiotlb_no_use && !io_tlb_nslabs) { io_tlb_nslabs = (default_size >> IO_TLB_SHIFT); io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); } @@ -244,7 +248,7 @@ swiotlb_late_init_with_default_size(size_t default_size) unsigned int order; int rc = 0; - if (!io_tlb_nslabs) { + if (!swiotlb_no_use && !io_tlb_nslabs) { io_tlb_nslabs = (default_size >> IO_TLB_SHIFT); io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); } -- 1.7.10.4