From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932190AbVLLUCJ (ORCPT ); Mon, 12 Dec 2005 15:02:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932191AbVLLUCH (ORCPT ); Mon, 12 Dec 2005 15:02:07 -0500 Received: from mail.kroah.org ([69.55.234.183]:43173 "EHLO perch.kroah.org") by vger.kernel.org with ESMTP id S932194AbVLLUCF (ORCPT ); Mon, 12 Dec 2005 15:02:05 -0500 Date: Mon, 12 Dec 2005 12:01:29 -0800 From: Greg Kroah-Hartman To: Linus Torvalds , Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-pci@atrey.karlin.mff.cuni.cz, ak@muc.de Subject: [patch 3/4] x86_64/i386: Correct for broken MCFG tables on K8 systems Message-ID: <20051212200129.GD27657@kroah.com> References: <20051212192030.873030000@press.kroah.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="x86_64-i386-correct-for-broken-mcfg-tables-on-k8-systems.patch" In-Reply-To: <20051212200044.GA27657@kroah.com> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Andi Kleen They report all busses as MMCONFIG capable, but it never works for the internal devices in the CPU's builtin northbridge. This causes problems - some devices are not visible and on x86-64 the IOMMU is not detected, causing boot failures on systems with >3GB of RAM. It also breaks AGP. Workaround just probes all func 0 devices on bus 0 (the internal northbridge is currently always on bus 0) and if they are not accessible using MCFG they are put into a special fallback bitmap. On systems where it isn't we assume the BIOS vendor supplied correct MCFG. Requires the earlier patch for mmconfig type1 fallback Signed-off-by: Andi Kleen Signed-off-by: Greg Kroah-Hartman --- arch/i386/pci/mmconfig.c | 45 ++++++++++++++++++++++++++++++++++++++++++--- arch/x86_64/pci/mmconfig.c | 36 ++++++++++++++++++++++++++++++++++-- 2 files changed, 76 insertions(+), 5 deletions(-) --- greg-2.6.orig/arch/x86_64/pci/mmconfig.c +++ greg-2.6/arch/x86_64/pci/mmconfig.c @@ -8,10 +8,13 @@ #include #include #include +#include #include "pci.h" #define MMCONFIG_APER_SIZE (256*1024*1024) +static DECLARE_BITMAP(fallback_slots, 32); + /* Static virtual mapping of the MMCONFIG aperture */ struct mmcfg_virt { struct acpi_table_mcfg_config *cfg; @@ -40,9 +43,12 @@ static char *get_virt(unsigned int seg, } } -static inline char *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn) +static char *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn) { - char *addr = get_virt(seg, bus); + char *addr; + if (seg == 0 && bus == 0 && test_bit(PCI_SLOT(devfn), &fallback_slots)) + return NULL; + addr = get_virt(seg, bus); if (!addr) return NULL; return addr + ((bus << 20) | (devfn << 12)); @@ -109,6 +115,30 @@ static struct pci_raw_ops pci_mmcfg = { .write = pci_mmcfg_write, }; +/* K8 systems have some devices (typically in the builtin northbridge) + that are only accessible using type1 + Normally this can be expressed in the MCFG by not listing them + and assigning suitable _SEGs, but this isn't implemented in some BIOS. + Instead try to discover all devices on bus 0 that are unreachable using MM + and fallback for them. + We only do this for bus 0/seg 0 */ +static __init void unreachable_devices(void) +{ + int i; + for (i = 0; i < 32; i++) { + u32 val1; + char *addr; + + pci_conf1_read(0, 0, PCI_DEVFN(i,0), 0, 4, &val1); + if (val1 == 0xffffffff) + continue; + addr = pci_dev_base(0, 0, PCI_DEVFN(i, 0)); + if (addr == NULL || readl(addr) != val1) { + set_bit(i, &fallback_slots); + } + } +} + static int __init pci_mmcfg_init(void) { int i; @@ -139,6 +169,8 @@ static int __init pci_mmcfg_init(void) printk(KERN_INFO "PCI: Using MMCONFIG at %x\n", pci_mmcfg_config[i].base_address); } + unreachable_devices(); + raw_pci_ops = &pci_mmcfg; pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF; --- greg-2.6.orig/arch/i386/pci/mmconfig.c +++ greg-2.6/arch/i386/pci/mmconfig.c @@ -19,14 +19,20 @@ /* The base address of the last MMCONFIG device accessed */ static u32 mmcfg_last_accessed_device; +static DECLARE_BITMAP(fallback_slots, 32); + /* * Functions for accessing PCI configuration space with MMCONFIG accesses */ -static u32 get_base_addr(unsigned int seg, int bus) +static u32 get_base_addr(unsigned int seg, int bus, unsigned devfn) { int cfg_num = -1; struct acpi_table_mcfg_config *cfg; + if (seg == 0 && bus == 0 && + test_bit(PCI_SLOT(devfn), fallback_slots)) + return 0; + while (1) { ++cfg_num; if (cfg_num >= pci_mmcfg_config_num) { @@ -60,7 +66,7 @@ static int pci_mmcfg_read(unsigned int s if (!value || (bus > 255) || (devfn > 255) || (reg > 4095)) return -EINVAL; - base = get_base_addr(seg, bus); + base = get_base_addr(seg, bus, devfn); if (!base) return pci_conf1_read(seg,bus,devfn,reg,len,value); @@ -94,7 +100,7 @@ static int pci_mmcfg_write(unsigned int if ((bus > 255) || (devfn > 255) || (reg > 4095)) return -EINVAL; - base = get_base_addr(seg, bus); + base = get_base_addr(seg, bus, devfn); if (!base) return pci_conf1_write(seg,bus,devfn,reg,len,value); @@ -124,6 +130,37 @@ static struct pci_raw_ops pci_mmcfg = { .write = pci_mmcfg_write, }; +/* K8 systems have some devices (typically in the builtin northbridge) + that are only accessible using type1 + Normally this can be expressed in the MCFG by not listing them + and assigning suitable _SEGs, but this isn't implemented in some BIOS. + Instead try to discover all devices on bus 0 that are unreachable using MM + and fallback for them. + We only do this for bus 0/seg 0 */ +static __init void unreachable_devices(void) +{ + int i; + unsigned long flags; + + for (i = 0; i < 32; i++) { + u32 val1; + u32 addr; + + pci_conf1_read(0, 0, PCI_DEVFN(i, 0), 0, 4, &val1); + if (val1 == 0xffffffff) + continue; + + /* Locking probably not needed, but safer */ + spin_lock_irqsave(&pci_config_lock, flags); + addr = get_base_addr(0, 0, PCI_DEVFN(i, 0)); + if (addr != 0) + pci_exp_set_dev_base(addr, 0, PCI_DEVFN(i, 0)); + if (addr == 0 || readl((u32 *)addr) != val1) + set_bit(i, fallback_slots); + spin_unlock_irqrestore(&pci_config_lock, flags); + } +} + static int __init pci_mmcfg_init(void) { if ((pci_probe & PCI_PROBE_MMCONF) == 0) @@ -139,6 +176,8 @@ static int __init pci_mmcfg_init(void) raw_pci_ops = &pci_mmcfg; pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF; + unreachable_devices(); + out: return 0; } --