Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752292Ab2EVG7Y (ORCPT ); Tue, 22 May 2012 02:59:24 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:51286 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751586Ab2EVG7X (ORCPT ); Tue, 22 May 2012 02:59:23 -0400 X-IronPort-AV: E=Sophos;i="4.75,637,1330876800"; d="scan'208";a="5009877" Message-ID: <4FBB3A23.50102@cn.fujitsu.com> Date: Tue, 22 May 2012 15:02:59 +0800 From: Wen Congyang User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100413 Fedora/3.0.4-2.fc13 Thunderbird/3.0.4 MIME-Version: 1.0 To: rob@landley.net, tglx@linutronix.de, Ingo Molnar , x86@kernel.org, "linux-kernel@vger.kernel.org" Subject: [PATCH 1/2] x86: add max_addr boot option X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/05/22 14:57:54, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/05/22 14:57:55, Serialize complete at 2012/05/22 14:57:55 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3347 Lines: 106 Currently, the boot option max_addr is only supported on ia64 platform. We also need it on x86 platform. For example: There are two nodes: NODE#0 address range 0x00000000 00000000 - 0x00010000 00000000 NODE#1 address range 0x00010000 00000000 - 0x00020000 00000000 If we only want to use node0, we can specify the max_addr. The boot option "mem=" can do the same thing now. But the boot option "mem=" means the total memory used by the system. If we tell the user that the boot option "mem=" can do this, it will confuse the user. So we need an new boot option "max_addr" on x86 platform. Signed-off-by: Wen Congyang --- Documentation/kernel-parameters.txt | 2 +- arch/x86/kernel/e820.c | 36 +++++++++++++++++++++++++++++++++++ 2 files changed, 37 insertions(+), 1 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index c1601e5..fe80e58 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1409,7 +1409,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. yeeloong laptop. Example: machtype=lemote-yeeloong-2f-7inch - max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater + max_addr=nn[KMG] [KNL,BOOT,ia64,X86] All physical memory greater than or equal to this physical address is ignored. maxcpus= [SMP] Maximum number of processors that an SMP kernel diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index 62d61e9..2a6bec7 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -47,6 +47,7 @@ unsigned long pci_mem_start = 0xaeedbabe; #ifdef CONFIG_PCI EXPORT_SYMBOL(pci_mem_start); #endif +static u64 max_addr = ~0ULL; /* * This function checks if any part of the range is mapped @@ -117,6 +118,20 @@ static void __init __e820_add_region(struct e820map *e820x, u64 start, u64 size, return; } + if (start >= max_addr) { + printk(KERN_INFO "Ingoring memory: %016Lx - %016Lx\n", + (unsigned long long)start, + (unsigned long long)(start + size)); + return; + } + + if (max_addr - start < size) { + printk(KERN_INFO "Ingoring memory: %016Lx - %016Lx\n", + (unsigned long long)max_addr, + (unsigned long long)(start + size)); + size = max_addr - start; + } + e820x->map[x].addr = start; e820x->map[x].size = size; e820x->map[x].type = type; @@ -835,6 +850,22 @@ static int __init parse_memopt(char *p) } early_param("mem", parse_memopt); +static int __init parse_memmax_opt(char *p) +{ + char *oldp; + + if (!p) + return -EINVAL; + + oldp = p; + max_addr = memparse(p, &p); + if (p == oldp) + return -EINVAL; + + return 0; +} +early_param("max_addr", parse_memmax_opt); + static int __init parse_memmap_opt(char *p) { char *oldp; @@ -881,6 +912,11 @@ early_param("memmap", parse_memmap_opt); void __init finish_e820_parsing(void) { + if (max_addr != ~0ULL) { + userdef = 1; + e820_remove_range(max_addr, ULLONG_MAX - max_addr, E820_RAM, 1); + } + if (userdef) { u32 nr = e820.nr_map; -- 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/