158 lines
3.4 KiB
C
158 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/rcupdate.h>
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#include <asm/e820.h>
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#include <asm/pci_x86.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 pci_mmcfg_region *cfg = pci_mmconfig_lookup(seg, bus);
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if (cfg)
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return cfg->address;
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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 | PCI_MMCFG_BUS_OFFSET(bus) | (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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err: *value = -1;
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return -EINVAL;
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}
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rcu_read_lock();
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base = get_base_addr(seg, bus, devfn);
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if (!base) {
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rcu_read_unlock();
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goto err;
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}
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raw_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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raw_spin_unlock_irqrestore(&pci_config_lock, flags);
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rcu_read_unlock();
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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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rcu_read_lock();
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base = get_base_addr(seg, bus, devfn);
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if (!base) {
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rcu_read_unlock();
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return -EINVAL;
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}
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raw_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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raw_spin_unlock_irqrestore(&pci_config_lock, flags);
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rcu_read_unlock();
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return 0;
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}
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const 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_init(void)
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{
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printk(KERN_INFO "PCI: Using MMCONFIG for extended config space\n");
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raw_pci_ext_ops = &pci_mmcfg;
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return 1;
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}
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void __init pci_mmcfg_arch_free(void)
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{
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}
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int pci_mmcfg_arch_map(struct pci_mmcfg_region *cfg)
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{
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return 0;
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}
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void pci_mmcfg_arch_unmap(struct pci_mmcfg_region *cfg)
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{
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unsigned long flags;
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/* Invalidate the cached mmcfg map entry. */
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raw_spin_lock_irqsave(&pci_config_lock, flags);
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mmcfg_last_accessed_device = 0;
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raw_spin_unlock_irqrestore(&pci_config_lock, flags);
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}
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