1 files changed, 157 insertions, 0 deletions

diff --git a/arch/x86/pci/mmconfig_64.c b/arch/x86/pci/mmconfig_64.c
new file mode 100644
index 000000000000..4095e4d66a1d
--- /dev/null
+++ b/arch/x86/pci/mmconfig_64.c
@@ -0,0 +1,157 @@
+/*
+ * 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;
+        if (seg == 0 && bus < PCI_MMCFG_MAX_CHECK_BUS &&
+                test_bit(32*bus + PCI_SLOT(devfn), pci_mmcfg_fallback_slots))
+                return NULL;
+        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))) {
+                *value = -1;
+                return -EINVAL;
+        }
+
+        addr = pci_dev_base(seg, bus, devfn);
+        if (!addr)
+                return pci_conf1_read(seg,bus,devfn,reg,len,value);
+
+        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 pci_conf1_write(seg,bus,devfn,reg,len,value);
+
+        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_reachable(unsigned int seg, unsigned int bus,
+                                    unsigned int devfn)
+{
+        return pci_dev_base(seg, bus, devfn) != NULL;
+}
+
+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_ops = &pci_mmcfg;
+        return 1;
+}