928cf8c627
When there is no entry for a bus in MCFG fall back to type1. This is especially important on K8 systems where always some devices can't be accessed using mmconfig (in particular the builtin northbridge doesn't support it for its own devices) Cc: <gregkh@suse.de> Cc: <jgarzik@pobox.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
146 lines
3.1 KiB
C
146 lines
3.1 KiB
C
/*
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* Copyright (C) 2004 Matthew Wilcox <matthew@wil.cx>
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* Copyright (C) 2004 Intel Corp.
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*
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* This code is released under the GNU General Public License version 2.
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*/
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/*
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* mmconfig.c - Low-level direct PCI config space access via MMCONFIG
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*/
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#include <linux/pci.h>
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#include <linux/init.h>
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#include <linux/acpi.h>
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#include "pci.h"
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#define mmcfg_virt_addr ((void __iomem *) fix_to_virt(FIX_PCIE_MCFG))
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/* The base address of the last MMCONFIG device accessed */
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static u32 mmcfg_last_accessed_device;
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/*
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* Functions for accessing PCI configuration space with MMCONFIG accesses
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*/
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static u32 get_base_addr(unsigned int seg, int bus)
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{
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int cfg_num = -1;
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struct acpi_table_mcfg_config *cfg;
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while (1) {
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++cfg_num;
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if (cfg_num >= pci_mmcfg_config_num) {
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/* Not found - fallback to type 1 */
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return 0;
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}
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cfg = &pci_mmcfg_config[cfg_num];
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if (cfg->pci_segment_group_number != seg)
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continue;
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if ((cfg->start_bus_number <= bus) &&
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(cfg->end_bus_number >= bus))
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return cfg->base_address;
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}
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}
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static inline void pci_exp_set_dev_base(unsigned int base, int bus, int devfn)
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{
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u32 dev_base = base | (bus << 20) | (devfn << 12);
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if (dev_base != mmcfg_last_accessed_device) {
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mmcfg_last_accessed_device = dev_base;
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set_fixmap_nocache(FIX_PCIE_MCFG, dev_base);
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}
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}
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static int pci_mmcfg_read(unsigned int seg, unsigned int bus,
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unsigned int devfn, int reg, int len, u32 *value)
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{
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unsigned long flags;
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u32 base;
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if (!value || (bus > 255) || (devfn > 255) || (reg > 4095))
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return -EINVAL;
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base = get_base_addr(seg, bus);
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if (!base)
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return pci_conf1_read(seg,bus,devfn,reg,len,value);
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spin_lock_irqsave(&pci_config_lock, flags);
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pci_exp_set_dev_base(base, bus, devfn);
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switch (len) {
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case 1:
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*value = readb(mmcfg_virt_addr + reg);
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break;
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case 2:
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*value = readw(mmcfg_virt_addr + reg);
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break;
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case 4:
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*value = readl(mmcfg_virt_addr + reg);
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break;
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}
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spin_unlock_irqrestore(&pci_config_lock, flags);
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return 0;
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}
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static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
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unsigned int devfn, int reg, int len, u32 value)
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{
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unsigned long flags;
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u32 base;
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if ((bus > 255) || (devfn > 255) || (reg > 4095))
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return -EINVAL;
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base = get_base_addr(seg, bus);
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if (!base)
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return pci_conf1_write(seg,bus,devfn,reg,len,value);
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spin_lock_irqsave(&pci_config_lock, flags);
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pci_exp_set_dev_base(base, bus, devfn);
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switch (len) {
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case 1:
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writeb(value, mmcfg_virt_addr + reg);
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break;
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case 2:
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writew(value, mmcfg_virt_addr + reg);
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break;
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case 4:
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writel(value, mmcfg_virt_addr + reg);
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break;
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}
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spin_unlock_irqrestore(&pci_config_lock, flags);
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return 0;
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}
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static struct pci_raw_ops pci_mmcfg = {
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.read = pci_mmcfg_read,
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.write = pci_mmcfg_write,
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};
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static int __init pci_mmcfg_init(void)
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{
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if ((pci_probe & PCI_PROBE_MMCONF) == 0)
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goto out;
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acpi_table_parse(ACPI_MCFG, acpi_parse_mcfg);
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if ((pci_mmcfg_config_num == 0) ||
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(pci_mmcfg_config == NULL) ||
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(pci_mmcfg_config[0].base_address == 0))
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goto out;
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printk(KERN_INFO "PCI: Using MMCONFIG\n");
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raw_pci_ops = &pci_mmcfg;
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pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
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out:
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return 0;
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}
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arch_initcall(pci_mmcfg_init);
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