Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754477Ab3IXKH3 (ORCPT ); Tue, 24 Sep 2013 06:07:29 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:22773 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753967Ab3IXKH0 (ORCPT ); Tue, 24 Sep 2013 06:07:26 -0400 X-IronPort-AV: E=Sophos;i="4.90,969,1371052800"; d="scan'208";a="8606656" Message-ID: <52416431.1090107@cn.fujitsu.com> Date: Tue, 24 Sep 2013 18:06:41 +0800 From: Zhang Yanfei User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130514 Thunderbird/17.0.6 MIME-Version: 1.0 To: Zhang Yanfei , "Rafael J . Wysocki" , lenb@kernel.org, Thomas Gleixner , mingo@elte.hu, "H. Peter Anvin" , Andrew Morton , Tejun Heo , Toshi Kani , Wanpeng Li , Thomas Renninger , Yinghai Lu , Jiang Liu , Wen Congyang , Lai Jiangshan , isimatu.yasuaki@jp.fujitsu.com, izumi.taku@jp.fujitsu.com, Mel Gorman , Minchan Kim , mina86@mina86.com, gong.chen@linux.intel.com, vasilis.liaskovitis@profitbricks.com, lwoodman@redhat.com, Rik van Riel , jweiner@redhat.com, prarit@redhat.com CC: "x86@kernel.org" , linux-doc@vger.kernel.org, "linux-kernel@vger.kernel.org" , Linux MM , linux-acpi@vger.kernel.org, imtangchen@gmail.com, Zhang Yanfei Subject: [PATCH 3/6] x86/mm: Factor out of top-down direct mapping setup References: <524162DA.30004@cn.fujitsu.com> In-Reply-To: <524162DA.30004@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/09/24 18:05:43, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/09/24 18:05:44, Serialize complete at 2013/09/24 18:05:44 Content-Transfer-Encoding: 7bit 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: 4208 Lines: 128 From: Tang Chen This patch introduces a new function memory_map_top_down to factor out of the top-down direct memory mapping pagetable setup. This is also a preparation for the following patch, which will introduce the bottom-up memory mapping. That said, we will put the two ways of pagetable setup into separate functions, and choose to use which way in init_mem_mapping, which makes the code more clear. Signed-off-by: Tang Chen Signed-off-by: Zhang Yanfei --- arch/x86/mm/init.c | 70 ++++++++++++++++++++++++++++++++------------------- 1 files changed, 44 insertions(+), 26 deletions(-) diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 04664cd..73e79e6 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -401,27 +401,27 @@ static unsigned long __init init_range_memory_mapping( /* (PUD_SHIFT-PMD_SHIFT)/2 */ #define STEP_SIZE_SHIFT 5 -void __init init_mem_mapping(void) + +/** + * memory_map_top_down - Map [map_start, map_end) top down + * @map_start: start address of the target memory range + * @map_end: end address of the target memory range + * + * This function will setup direct mapping for memory range [map_start, map_end) + * in a heuristic way. In the beginning, step_size is small. The more memory we + * map memory in the next loop. + */ +static void __init memory_map_top_down(unsigned long map_start, + unsigned long map_end) { - unsigned long end, real_end, start, last_start; + unsigned long real_end, start, last_start; unsigned long step_size; unsigned long addr; unsigned long mapped_ram_size = 0; unsigned long new_mapped_ram_size; - probe_page_size_mask(); - -#ifdef CONFIG_X86_64 - end = max_pfn << PAGE_SHIFT; -#else - end = max_low_pfn << PAGE_SHIFT; -#endif - - /* the ISA range is always mapped regardless of memory holes */ - init_memory_mapping(0, ISA_END_ADDRESS); - /* xen has big range in reserved near end of ram, skip it at first.*/ - addr = memblock_find_in_range(ISA_END_ADDRESS, end, PMD_SIZE, PMD_SIZE); + addr = memblock_find_in_range(map_start, map_end, PMD_SIZE, PMD_SIZE); real_end = addr + PMD_SIZE; /* step_size need to be small so pgt_buf from BRK could cover it */ @@ -430,19 +430,13 @@ void __init init_mem_mapping(void) min_pfn_mapped = real_end >> PAGE_SHIFT; last_start = start = real_end; - /* - * We start from the top (end of memory) and go to the bottom. - * The memblock_find_in_range() gets us a block of RAM from the - * end of RAM in [min_pfn_mapped, max_pfn_mapped) used as new pages - * for page table. - */ - while (last_start > ISA_END_ADDRESS) { + while (last_start > map_start) { if (last_start > step_size) { start = round_down(last_start - 1, step_size); - if (start < ISA_END_ADDRESS) - start = ISA_END_ADDRESS; + if (start < map_start) + start = map_start; } else - start = ISA_END_ADDRESS; + start = map_start; new_mapped_ram_size = init_range_memory_mapping(start, last_start); last_start = start; @@ -453,8 +447,32 @@ void __init init_mem_mapping(void) mapped_ram_size += new_mapped_ram_size; } - if (real_end < end) - init_range_memory_mapping(real_end, end); + if (real_end < map_end) + init_range_memory_mapping(real_end, map_end); +} + +void __init init_mem_mapping(void) +{ + unsigned long end; + + probe_page_size_mask(); + +#ifdef CONFIG_X86_64 + end = max_pfn << PAGE_SHIFT; +#else + end = max_low_pfn << PAGE_SHIFT; +#endif + + /* the ISA range is always mapped regardless of memory holes */ + init_memory_mapping(0, ISA_END_ADDRESS); + + /* + * We start from the top (end of memory) and go to the bottom. + * The memblock_find_in_range() gets us a block of RAM from the + * end of RAM in [min_pfn_mapped, max_pfn_mapped) used as new pages + * for page table. + */ + memory_map_top_down(ISA_END_ADDRESS, end); #ifdef CONFIG_X86_64 if (max_pfn > max_low_pfn) { -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/