149 lines
3.4 KiB
C
149 lines
3.4 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 <asm/e820.h>
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#include "pci.h"
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/* Assume systems with more busses have correct MCFG */
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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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static int mmcfg_last_accessed_cpu;
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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, unsigned devfn)
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{
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struct acpi_mcfg_allocation *cfg;
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int cfg_num;
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if (seg == 0 && bus < PCI_MMCFG_MAX_CHECK_BUS &&
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test_bit(PCI_SLOT(devfn) + 32*bus, pci_mmcfg_fallback_slots))
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return 0;
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for (cfg_num = 0; cfg_num < pci_mmcfg_config_num; cfg_num++) {
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cfg = &pci_mmcfg_config[cfg_num];
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if (cfg->pci_segment == seg &&
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(cfg->start_bus_number <= bus) &&
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(cfg->end_bus_number >= bus))
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return cfg->address;
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}
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/* Fall back to type 0 */
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return 0;
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}
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/*
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* This is always called under pci_config_lock
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*/
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static 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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int cpu = smp_processor_id();
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if (dev_base != mmcfg_last_accessed_device ||
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cpu != mmcfg_last_accessed_cpu) {
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mmcfg_last_accessed_device = dev_base;
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mmcfg_last_accessed_cpu = cpu;
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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 ((bus > 255) || (devfn > 255) || (reg > 4095)) {
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*value = -1;
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return -EINVAL;
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}
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base = get_base_addr(seg, bus, devfn);
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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 = mmio_config_readb(mmcfg_virt_addr + reg);
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break;
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case 2:
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*value = mmio_config_readw(mmcfg_virt_addr + reg);
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break;
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case 4:
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*value = mmio_config_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, devfn);
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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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mmio_config_writeb(mmcfg_virt_addr + reg, value);
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break;
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case 2:
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mmio_config_writew(mmcfg_virt_addr + reg, value);
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break;
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case 4:
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mmio_config_writel(mmcfg_virt_addr + reg, value);
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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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int __init pci_mmcfg_arch_reachable(unsigned int seg, unsigned int bus,
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unsigned int devfn)
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{
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return get_base_addr(seg, bus, devfn) != 0;
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}
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int __init pci_mmcfg_arch_init(void)
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{
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printk(KERN_INFO "PCI: Using MMCONFIG\n");
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raw_pci_ops = &pci_mmcfg;
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return 1;
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}
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