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Diffstat (limited to 'arch/i386/pci/mmconfig.c')
-rw-r--r--arch/i386/pci/mmconfig.c122
1 files changed, 122 insertions, 0 deletions
diff --git a/arch/i386/pci/mmconfig.c b/arch/i386/pci/mmconfig.c
new file mode 100644
index 000000000000..021a50aa51f4
--- /dev/null
+++ b/arch/i386/pci/mmconfig.c
@@ -0,0 +1,122 @@
+/*
+ * 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 "pci.h"
+
+/* The physical address of the MMCONFIG aperture. Set from ACPI tables. */
+u32 pci_mmcfg_base_addr;
+
+#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;
+
+/*
+ * Functions for accessing PCI configuration space with MMCONFIG accesses
+ */
+
+static inline void pci_exp_set_dev_base(int bus, int devfn)
+{
+ u32 dev_base = pci_mmcfg_base_addr | (bus << 20) | (devfn << 12);
+ if (dev_base != mmcfg_last_accessed_device) {
+ mmcfg_last_accessed_device = dev_base;
+ 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;
+
+ if (!value || (bus > 255) || (devfn > 255) || (reg > 4095))
+ return -EINVAL;
+
+ spin_lock_irqsave(&pci_config_lock, flags);
+
+ pci_exp_set_dev_base(bus, devfn);
+
+ switch (len) {
+ case 1:
+ *value = readb(mmcfg_virt_addr + reg);
+ break;
+ case 2:
+ *value = readw(mmcfg_virt_addr + reg);
+ break;
+ case 4:
+ *value = 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;
+
+ if ((bus > 255) || (devfn > 255) || (reg > 4095))
+ return -EINVAL;
+
+ spin_lock_irqsave(&pci_config_lock, flags);
+
+ pci_exp_set_dev_base(bus, devfn);
+
+ switch (len) {
+ case 1:
+ writeb(value, mmcfg_virt_addr + reg);
+ break;
+ case 2:
+ writew(value, mmcfg_virt_addr + reg);
+ break;
+ case 4:
+ writel(value, mmcfg_virt_addr + reg);
+ 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,
+};
+
+static int __init pci_mmcfg_init(void)
+{
+ if ((pci_probe & PCI_PROBE_MMCONF) == 0)
+ goto out;
+ if (!pci_mmcfg_base_addr)
+ goto out;
+
+ /* Kludge for now. Don't use mmconfig on AMD systems because
+ those have some busses where mmconfig doesn't work,
+ and we don't parse ACPI MCFG well enough to handle that.
+ Remove when proper handling is added. */
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
+ goto out;
+
+ printk(KERN_INFO "PCI: Using MMCONFIG\n");
+ raw_pci_ops = &pci_mmcfg;
+ pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
+
+ out:
+ return 0;
+}
+
+arch_initcall(pci_mmcfg_init);