From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750696AbXBWBlm (ORCPT ); Thu, 22 Feb 2007 20:41:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751544AbXBWBlm (ORCPT ); Thu, 22 Feb 2007 20:41:42 -0500 Received: from mga09.intel.com ([134.134.136.24]:2760 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750696AbXBWBll (ORCPT ); Thu, 22 Feb 2007 20:41:41 -0500 X-ExtLoop1: 1 X-IronPort-AV: i="4.14,208,1170662400"; d="scan'208"; a="49742949:sNHT25037667" Date: Thu, 22 Feb 2007 17:06:17 -0800 From: Venkatesh Pallipadi To: linux-kernel , Thomas Gleixner , Ingo Molnar Subject: [PATCH 1/5] RT kernel: force detect HPET from PCI space Message-ID: <20070222170616.A27455@unix-os.sc.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Patchset enables force detection of HPET, when it is not listed by BIOS. and enables use of HPET as a event source. HPET timers configures in stamdard interrupt mode can be used as dependable per CPU timer on laptops that are known to have LAPIC stoppage with ACPI C3 state. Patch is against rt kernel (2.6.20-rt8) and patch enables only x86-64 right now. This patch: Detect HPET by looking at PCI space, even when BIOS does not list HPET device. This is useful to use HPET as dependable per CPU timer with tickless kernels. Signed-off-by: Venkatesh Pallipadi Index: linux-2.6.21-rc-mm/arch/i386/kernel/quirks.c =================================================================== --- linux-2.6.21-rc-mm.orig/arch/i386/kernel/quirks.c +++ linux-2.6.21-rc-mm/arch/i386/kernel/quirks.c @@ -48,3 +48,58 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_IN DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_E7525_MCH, quirk_intel_irqbalance); DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_E7520_MCH, quirk_intel_irqbalance); #endif + +#if defined(CONFIG_HPET_TIMER) +unsigned long force_hpet_address; + +static void __init force_enable_hpet(struct pci_dev *dev) +{ + u32 val, rcba; + void __iomem *base; + + if (hpet_address) + return; + + pci_read_config_dword(dev, 0xF0, &rcba); + rcba &= 0xFFFFC000; + if (rcba == 0) { + printk(KERN_DEBUG "RCBA disabled. Cannot force enable HPET\n"); + return; + } + + /* use bits 31:14, 16 kB aligned */ + base = ioremap_nocache(rcba, 0x4000); + if (base == NULL) { + printk(KERN_DEBUG "ioremap failed. Cannot force enable HPET\n"); + return; + } + + /* read the Function Disable register, dword mode only */ + val = readl(base + 0x3404); + + if (!(val & 0x80)) { + /* HPET disabled in HPTC. Trying to enable */ + writel(val | 0x80, base + 0x3404); + } + + val = readl(base + 0x3404); + + if (!(val & 0x80)) { + printk(KERN_DEBUG "Failed to force enable HPET\n"); + } else { + val = val & 0x3; + force_hpet_address = 0xFED00000 | (val << 12); + printk(KERN_DEBUG "Force enabled HPET. Base address 0x%x\n", + force_hpet_address); + } + + iounmap(base); +} + +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB2_0, force_enable_hpet); +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH6_1, force_enable_hpet); +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_1, force_enable_hpet); +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_31, force_enable_hpet); +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH8_1, force_enable_hpet); +#endif + Index: linux-2.6.21-rc-mm/include/asm-i386/hpet.h =================================================================== --- linux-2.6.21-rc-mm.orig/include/asm-i386/hpet.h +++ linux-2.6.21-rc-mm/include/asm-i386/hpet.h @@ -91,6 +91,7 @@ #define HPET_TICK_RATE (HZ * 100000UL) extern unsigned long hpet_address; /* hpet memory map physical address */ +extern unsigned long force_hpet_address;/* hpet memory detected by quirk */ extern int is_hpet_enabled(void); #ifdef CONFIG_X86_64 Index: linux-2.6.21-rc-mm/include/asm-x86_64/hpet.h =================================================================== --- linux-2.6.21-rc-mm.orig/include/asm-x86_64/hpet.h +++ linux-2.6.21-rc-mm/include/asm-x86_64/hpet.h @@ -63,6 +63,7 @@ extern unsigned int hpet_calibrate_tsc(v extern int hpet_use_timer; extern unsigned long hpet_address; +extern unsigned long force_hpet_address; extern unsigned long hpet_period; extern unsigned long hpet_tick;