From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933778AbXGKTbg (ORCPT ); Wed, 11 Jul 2007 15:31:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1765338AbXGKTUA (ORCPT ); Wed, 11 Jul 2007 15:20:00 -0400 Received: from terminus.zytor.com ([192.83.249.54]:38288 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932636AbXGKTTn (ORCPT ); Wed, 11 Jul 2007 15:19:43 -0400 From: "H. Peter Anvin" To: torvalds@linux-foundation.org, andi@firstfloor.org, linux-kernel@vger.kernel.org Cc: "H. Peter Anvin" Subject: [x86 setup 25/33] Memory probing support for the new x86 setup code Date: Wed, 11 Jul 2007 12:18:50 -0700 Message-Id: <11841815422973-git-send-email-hpa@zytor.com> X-Mailer: git-send-email 1.5.2.2 In-Reply-To: <11841815423652-git-send-email-hpa@zytor.com> References: <1184181538674-git-send-email-hpa@zytor.com> <118418153862-git-send-email-hpa@zytor.com> <11841815382283-git-send-email-hpa@zytor.com> <11841815392122-git-send-email-hpa@zytor.com> <11841815393975-git-send-email-hpa@zytor.com> <11841815393014-git-send-email-hpa@zytor.com> <1184181539416-git-send-email-hpa@zytor.com> <118418153972-git-send-email-hpa@zytor.com> <11841815391923-git-send-email-hpa@zytor.com> <11841815403678-git-send-email-hpa@zytor.com> <11841815403041-git-send-email-hpa@zytor.com> <11841815402349-git-send-email-hpa@zytor.com> <11841815401013-git-send-email-hpa@zytor.com> <1184181540369-git-send-email-hpa@zytor.com> <11841815401476-git-send-email-hpa@zytor.com> <11841815411443-git-send-email-hpa@zytor.com> <1184181541746-git-send-email-hpa@zytor.com> <11841815411436-git-send-email-hpa@zytor.com> <11841815412873-git-send-email-hpa@zytor.com> <11841815412175-git-send-email-hpa@zytor.com> <1184181541492-git-send-email-hpa@zytor.com> <11841815421028-git-send-email-hpa@zytor.com> <118418154292-git-send-email-hpa@zytor.com> <11841815421819-git-send-email-hpa@zytor.com> <11841815423652-git-send-email-hpa@zytor.com> Message-Id: <67bea0be0e4af894483cd7d8e725631d24e9c263.1184181208.git.hpa@zytor.com> In-Reply-To: <7aca4ce0a222438c94300a2ea535270a21db8812.1184181208.git.hpa@zytor.com> References: <7aca4ce0a222438c94300a2ea535270a21db8812.1184181208.git.hpa@zytor.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: H. Peter Anvin Probe memory (INT 15h: E820, E801, 88). Signed-off-by: H. Peter Anvin --- arch/i386/boot/memory.c | 99 +++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 99 insertions(+), 0 deletions(-) create mode 100644 arch/i386/boot/memory.c diff --git a/arch/i386/boot/memory.c b/arch/i386/boot/memory.c new file mode 100644 index 0000000..1a2e62d --- /dev/null +++ b/arch/i386/boot/memory.c @@ -0,0 +1,99 @@ +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * + * This file is part of the Linux kernel, and is made available under + * the terms of the GNU General Public License version 2. + * + * ----------------------------------------------------------------------- */ + +/* + * arch/i386/boot/memory.c + * + * Memory detection code + */ + +#include "boot.h" + +#define SMAP 0x534d4150 /* ASCII "SMAP" */ + +static int detect_memory_e820(void) +{ + u32 next = 0; + u32 size, id; + u8 err; + struct e820entry *desc = boot_params.e820_map; + + do { + size = sizeof(struct e820entry); + id = SMAP; + asm("int $0x15; setc %0" + : "=am" (err), "+b" (next), "+d" (id), "+c" (size), + "=m" (*desc) + : "D" (desc), "a" (0xe820)); + + if (err || id != SMAP) + break; + + boot_params.e820_entries++; + desc++; + } while (next && boot_params.e820_entries < E820MAX); + + return boot_params.e820_entries; +} + +static int detect_memory_e801(void) +{ + u16 ax, bx, cx, dx; + u8 err; + + bx = cx = dx = 0; + ax = 0xe801; + asm("stc; int $0x15; setc %0" + : "=m" (err), "+a" (ax), "+b" (bx), "+c" (cx), "+d" (dx)); + + if (err) + return -1; + + /* Do we really need to do this? */ + if (cx || dx) { + ax = cx; + bx = dx; + } + + if (ax > 15*1024) + return -1; /* Bogus! */ + + /* This ignores memory above 16MB if we have a memory hole + there. If someone actually finds a machine with a memory + hole at 16MB and no support for 0E820h they should probably + generate a fake e820 map. */ + boot_params.alt_mem_k = (ax == 15*1024) ? (dx << 6)+ax : ax; + + return 0; +} + +static int detect_memory_88(void) +{ + u16 ax; + u8 err; + + ax = 0x8800; + asm("stc; int $0x15; setc %0" : "=bcdm" (err), "+a" (ax)); + + boot_params.screen_info.ext_mem_k = ax; + + return -err; +} + +int detect_memory(void) +{ + if (detect_memory_e820() > 0) + return 0; + + if (!detect_memory_e801()) + return 0; + + return detect_memory_88(); +} -- 1.5.2.2