170 lines
3.7 KiB
C
170 lines
3.7 KiB
C
/*
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* mmconfig.c - Low-level direct PCI config space access via MMCONFIG
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*
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* This is an 64bit optimized version that always keeps the full mmconfig
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* space mapped. This allows lockless config space operation.
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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 <linux/bitmap.h>
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#include <asm/e820.h>
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#include "pci.h"
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/* Static virtual mapping of the MMCONFIG aperture */
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struct mmcfg_virt {
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struct acpi_mcfg_allocation *cfg;
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char __iomem *virt;
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};
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static struct mmcfg_virt *pci_mmcfg_virt;
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static char __iomem *get_virt(unsigned int seg, unsigned bus)
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{
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struct acpi_mcfg_allocation *cfg;
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int cfg_num;
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for (cfg_num = 0; cfg_num < pci_mmcfg_config_num; cfg_num++) {
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cfg = pci_mmcfg_virt[cfg_num].cfg;
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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 pci_mmcfg_virt[cfg_num].virt;
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}
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/* Fall back to type 0 */
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return NULL;
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}
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static char __iomem *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn)
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{
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char __iomem *addr;
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addr = get_virt(seg, bus);
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if (!addr)
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return NULL;
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return addr + ((bus << 20) | (devfn << 12));
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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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char __iomem *addr;
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/* Why do we have this when nobody checks it. How about a BUG()!? -AK */
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if (unlikely((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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addr = pci_dev_base(seg, bus, devfn);
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if (!addr)
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goto err;
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switch (len) {
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case 1:
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*value = mmio_config_readb(addr + reg);
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break;
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case 2:
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*value = mmio_config_readw(addr + reg);
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break;
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case 4:
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*value = mmio_config_readl(addr + reg);
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break;
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}
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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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char __iomem *addr;
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/* Why do we have this when nobody checks it. How about a BUG()!? -AK */
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if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095)))
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return -EINVAL;
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addr = pci_dev_base(seg, bus, devfn);
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if (!addr)
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return -EINVAL;
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switch (len) {
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case 1:
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mmio_config_writeb(addr + reg, value);
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break;
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case 2:
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mmio_config_writew(addr + reg, value);
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break;
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case 4:
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mmio_config_writel(addr + reg, value);
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break;
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}
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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 void __iomem * __init mcfg_ioremap(struct acpi_mcfg_allocation *cfg)
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{
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void __iomem *addr;
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u32 size;
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size = (cfg->end_bus_number + 1) << 20;
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addr = ioremap_nocache(cfg->address, size);
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if (addr) {
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printk(KERN_INFO "PCI: Using MMCONFIG at %Lx - %Lx\n",
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cfg->address, cfg->address + size - 1);
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}
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return addr;
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}
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int __init pci_mmcfg_arch_init(void)
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{
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int i;
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pci_mmcfg_virt = kzalloc(sizeof(*pci_mmcfg_virt) *
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pci_mmcfg_config_num, GFP_KERNEL);
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if (pci_mmcfg_virt == NULL) {
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printk(KERN_ERR "PCI: Can not allocate memory for mmconfig structures\n");
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return 0;
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}
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for (i = 0; i < pci_mmcfg_config_num; ++i) {
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pci_mmcfg_virt[i].cfg = &pci_mmcfg_config[i];
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pci_mmcfg_virt[i].virt = mcfg_ioremap(&pci_mmcfg_config[i]);
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if (!pci_mmcfg_virt[i].virt) {
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printk(KERN_ERR "PCI: Cannot map mmconfig aperture for "
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"segment %d\n",
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pci_mmcfg_config[i].pci_segment);
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pci_mmcfg_arch_free();
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return 0;
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}
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}
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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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int i;
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if (pci_mmcfg_virt == NULL)
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return;
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for (i = 0; i < pci_mmcfg_config_num; ++i) {
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if (pci_mmcfg_virt[i].virt) {
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iounmap(pci_mmcfg_virt[i].virt);
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pci_mmcfg_virt[i].virt = NULL;
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pci_mmcfg_virt[i].cfg = NULL;
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}
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}
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kfree(pci_mmcfg_virt);
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pci_mmcfg_virt = NULL;
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}
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