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