1 files changed, 148 insertions, 0 deletions
diff --git a/arch/x86/pci/mmconfig_32.c b/arch/x86/pci/mmconfig_32.c
new file mode 100644
index 00000000000..1bf5816d34c
--- /dev/null
+++ b/arch/x86/pci/mmconfig_32.c
@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) 2004 Matthew Wilcox <matthew@wil.cx>
+ * Copyright (C) 2004 Intel Corp.
+ *
+ * This code is released under the GNU General Public License version 2.
+ */
+
+/*
+ * mmconfig.c - Low-level direct PCI config space access via MMCONFIG
+ */
+
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/acpi.h>
+#include <asm/e820.h>
+#include "pci.h"
+
+/* Assume systems with more busses have correct MCFG */
+#define mmcfg_virt_addr ((void __iomem *) fix_to_virt(FIX_PCIE_MCFG))
+
+/* The base address of the last MMCONFIG device accessed */
+static u32 mmcfg_last_accessed_device;
+static int mmcfg_last_accessed_cpu;
+
+/*
+ * Functions for accessing PCI configuration space with MMCONFIG accesses
+ */
+static u32 get_base_addr(unsigned int seg, int bus, unsigned devfn)
+{
+	struct acpi_mcfg_allocation *cfg;
+	int cfg_num;
+
+	if (seg == 0 && bus < PCI_MMCFG_MAX_CHECK_BUS &&
+	    test_bit(PCI_SLOT(devfn) + 32*bus, pci_mmcfg_fallback_slots))
+		return 0;
+
+	for (cfg_num = 0; cfg_num < pci_mmcfg_config_num; cfg_num++) {
+		cfg = &pci_mmcfg_config[cfg_num];
+		if (cfg->pci_segment == seg &&
+		    (cfg->start_bus_number <= bus) &&
+		    (cfg->end_bus_number >= bus))
+			return cfg->address;
+	}
+
+	/* Fall back to type 0 */
+	return 0;
+}
+
+/*
+ * This is always called under pci_config_lock
+ */
+static void pci_exp_set_dev_base(unsigned int base, int bus, int devfn)
+{
+	u32 dev_base = base | (bus << 20) | (devfn << 12);
+	int cpu = smp_processor_id();
+	if (dev_base != mmcfg_last_accessed_device ||
+	    cpu != mmcfg_last_accessed_cpu) {
+		mmcfg_last_accessed_device = dev_base;
+		mmcfg_last_accessed_cpu = cpu;
+		set_fixmap_nocache(FIX_PCIE_MCFG, dev_base);
+	}
+}
+
+static int pci_mmcfg_read(unsigned int seg, unsigned int bus,
+			  unsigned int devfn, int reg, int len, u32 *value)
+{
+	unsigned long flags;
+	u32 base;
+
+	if ((bus > 255) || (devfn > 255) || (reg > 4095)) {
+		*value = -1;
+		return -EINVAL;
+	}
+
+	base = get_base_addr(seg, bus, devfn);
+	if (!base)
+		return pci_conf1_read(seg,bus,devfn,reg,len,value);
+
+	spin_lock_irqsave(&pci_config_lock, flags);
+
+	pci_exp_set_dev_base(base, bus, devfn);
+
+	switch (len) {
+	case 1:
+		*value = mmio_config_readb(mmcfg_virt_addr + reg);
+		break;
+	case 2:
+		*value = mmio_config_readw(mmcfg_virt_addr + reg);
+		break;
+	case 4:
+		*value = mmio_config_readl(mmcfg_virt_addr + reg);
+		break;
+	}
+	spin_unlock_irqrestore(&pci_config_lock, flags);
+
+	return 0;
+}
+
+static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
+			   unsigned int devfn, int reg, int len, u32 value)
+{
+	unsigned long flags;
+	u32 base;
+
+	if ((bus > 255) || (devfn > 255) || (reg > 4095))
+		return -EINVAL;
+
+	base = get_base_addr(seg, bus, devfn);
+	if (!base)
+		return pci_conf1_write(seg,bus,devfn,reg,len,value);
+
+	spin_lock_irqsave(&pci_config_lock, flags);
+
+	pci_exp_set_dev_base(base, bus, devfn);
+
+	switch (len) {
+	case 1:
+		mmio_config_writeb(mmcfg_virt_addr + reg, value);
+		break;
+	case 2:
+		mmio_config_writew(mmcfg_virt_addr + reg, value);
+		break;
+	case 4:
+		mmio_config_writel(mmcfg_virt_addr + reg, value);
+		break;
+	}
+	spin_unlock_irqrestore(&pci_config_lock, flags);
+
+	return 0;
+}
+
+static struct pci_raw_ops pci_mmcfg = {
+	.read =		pci_mmcfg_read,
+	.write =	pci_mmcfg_write,
+};
+
+int __init pci_mmcfg_arch_reachable(unsigned int seg, unsigned int bus,
+				    unsigned int devfn)
+{
+	return get_base_addr(seg, bus, devfn) != 0;
+}
+
+int __init pci_mmcfg_arch_init(void)
+{
+	printk(KERN_INFO "PCI: Using MMCONFIG\n");
+	raw_pci_ops = &pci_mmcfg;
+	return 1;
+}