Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758048AbcCaTnK (ORCPT ); Thu, 31 Mar 2016 15:43:10 -0400 Received: from mail-yw0-f181.google.com ([209.85.161.181]:34301 "EHLO mail-yw0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757873AbcCaTnH (ORCPT ); Thu, 31 Mar 2016 15:43:07 -0400 MIME-Version: 1.0 Date: Fri, 1 Apr 2016 01:13:06 +0530 X-Google-Sender-Auth: OOFyFpzhAOWgznnUpMJfuC2ighs Message-ID: Subject: Issue with ioremap From: punnaiah choudary kalluri To: linux-mm@kvack.org, "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1894 Lines: 51 Hi, We are using the pl353 smc controller for interfacing the nand in our zynq SOC. The driver for this controller is currently under mainline review. Recently we are moved to 4.4 kernel and observing issues with the driver. while debug, found that the issue is with the virtual address returned from the ioremap is not aligned to the physical address and causing nand access failures. the nand controller physical address starts at 0xE1000000 and the size is 16MB. the ioremap function in 4.3 kernel returns the virtual address that is aligned to the size but not the case in 4.4 kernel. this controller uses the bits [31:24] as base address and use rest all bits for configuring adders cycles, chip select information. so it expects the virtual address also aligned to 0xFF000000 otherwise the nand commands issued will fail. with >= 4.4 kernel 0xf0200000-0xf1201000 16781312 devm_ioremap+0x3c/0x70 phys=e1000000 ioremap with <= 4.3 kernel 0xf1000000-0xf2001000 16781312 devm_ioremap+0x38/0x68 phys=e1000000 ioremap the below hack fixes the issue. but its not a proper fix and it just pointing me the clue for this issue. so, any pointers and help to over come this issue ? is there a way to do static mapping for the above requirement? diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 8e3c9c5..fda58d6 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1340,9 +1340,13 @@ static struct vm_struct *__get_vm_area_node(unsigned long size, PAGE_SHIFT, IOREMAP_MAX_ORDER); size = PAGE_ALIGN(size); + if (size == 0x1000000) + align = 0x1000000; if (unlikely(!size)) return NULL; + printk(" size %x align %x\n", size, align); + area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node); if (unlikely(!area)) return NULL; Thanks, Punnaiah