1 files changed, 302 insertions, 0 deletions

diff --git a/arch/x86/pci/direct.c b/arch/x86/pci/direct.c
new file mode 100644
index 000000000000..431c9a51b157
--- /dev/null
+++ b/arch/x86/pci/direct.c
@@ -0,0 +1,302 @@
+/*
+ * direct.c - Low-level direct PCI config space access
+ */
+
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/dmi.h>
+#include "pci.h"
+
+/*
+ * Functions for accessing PCI configuration space with type 1 accesses
+ */
+
+#define PCI_CONF1_ADDRESS(bus, devfn, reg) \
+        (0x80000000 | (bus << 16) | (devfn << 8) | (reg & ~3))
+
+int pci_conf1_read(unsigned int seg, unsigned int bus,
+                          unsigned int devfn, int reg, int len, u32 *value)
+{
+        unsigned long flags;
+
+        if ((bus > 255) || (devfn > 255) || (reg > 255)) {
+                *value = -1;
+                return -EINVAL;
+        }
+
+        spin_lock_irqsave(&pci_config_lock, flags);
+
+        outl(PCI_CONF1_ADDRESS(bus, devfn, reg), 0xCF8);
+
+        switch (len) {
+        case 1:
+                *value = inb(0xCFC + (reg & 3));
+                break;
+        case 2:
+                *value = inw(0xCFC + (reg & 2));
+                break;
+        case 4:
+                *value = inl(0xCFC);
+                break;
+        }
+
+        spin_unlock_irqrestore(&pci_config_lock, flags);
+
+        return 0;
+}
+
+int pci_conf1_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 > 255)) 
+                return -EINVAL;
+
+        spin_lock_irqsave(&pci_config_lock, flags);
+
+        outl(PCI_CONF1_ADDRESS(bus, devfn, reg), 0xCF8);
+
+        switch (len) {
+        case 1:
+                outb((u8)value, 0xCFC + (reg & 3));
+                break;
+        case 2:
+                outw((u16)value, 0xCFC + (reg & 2));
+                break;
+        case 4:
+                outl((u32)value, 0xCFC);
+                break;
+        }
+
+        spin_unlock_irqrestore(&pci_config_lock, flags);
+
+        return 0;
+}
+
+#undef PCI_CONF1_ADDRESS
+
+struct pci_raw_ops pci_direct_conf1 = {
+        .read =         pci_conf1_read,
+        .write =        pci_conf1_write,
+};
+
+
+/*
+ * Functions for accessing PCI configuration space with type 2 accesses
+ */
+
+#define PCI_CONF2_ADDRESS(dev, reg)     (u16)(0xC000 | (dev << 8) | reg)
+
+static int pci_conf2_read(unsigned int seg, unsigned int bus,
+                          unsigned int devfn, int reg, int len, u32 *value)
+{
+        unsigned long flags;
+        int dev, fn;
+
+        if ((bus > 255) || (devfn > 255) || (reg > 255)) {
+                *value = -1;
+                return -EINVAL;
+        }
+
+        dev = PCI_SLOT(devfn);
+        fn = PCI_FUNC(devfn);
+
+        if (dev & 0x10) 
+                return PCIBIOS_DEVICE_NOT_FOUND;
+
+        spin_lock_irqsave(&pci_config_lock, flags);
+
+        outb((u8)(0xF0 | (fn << 1)), 0xCF8);
+        outb((u8)bus, 0xCFA);
+
+        switch (len) {
+        case 1:
+                *value = inb(PCI_CONF2_ADDRESS(dev, reg));
+                break;
+        case 2:
+                *value = inw(PCI_CONF2_ADDRESS(dev, reg));
+                break;
+        case 4:
+                *value = inl(PCI_CONF2_ADDRESS(dev, reg));
+                break;
+        }
+
+        outb(0, 0xCF8);
+
+        spin_unlock_irqrestore(&pci_config_lock, flags);
+
+        return 0;
+}
+
+static int pci_conf2_write(unsigned int seg, unsigned int bus,
+                           unsigned int devfn, int reg, int len, u32 value)
+{
+        unsigned long flags;
+        int dev, fn;
+
+        if ((bus > 255) || (devfn > 255) || (reg > 255)) 
+                return -EINVAL;
+
+        dev = PCI_SLOT(devfn);
+        fn = PCI_FUNC(devfn);
+
+        if (dev & 0x10) 
+                return PCIBIOS_DEVICE_NOT_FOUND;
+
+        spin_lock_irqsave(&pci_config_lock, flags);
+
+        outb((u8)(0xF0 | (fn << 1)), 0xCF8);
+        outb((u8)bus, 0xCFA);
+
+        switch (len) {
+        case 1:
+                outb((u8)value, PCI_CONF2_ADDRESS(dev, reg));
+                break;
+        case 2:
+                outw((u16)value, PCI_CONF2_ADDRESS(dev, reg));
+                break;
+        case 4:
+                outl((u32)value, PCI_CONF2_ADDRESS(dev, reg));
+                break;
+        }
+
+        outb(0, 0xCF8);    
+
+        spin_unlock_irqrestore(&pci_config_lock, flags);
+
+        return 0;
+}
+
+#undef PCI_CONF2_ADDRESS
+
+static struct pci_raw_ops pci_direct_conf2 = {
+        .read =         pci_conf2_read,
+        .write =        pci_conf2_write,
+};
+
+
+/*
+ * Before we decide to use direct hardware access mechanisms, we try to do some
+ * trivial checks to ensure it at least _seems_ to be working -- we just test
+ * whether bus 00 contains a host bridge (this is similar to checking
+ * techniques used in XFree86, but ours should be more reliable since we
+ * attempt to make use of direct access hints provided by the PCI BIOS).
+ *
+ * This should be close to trivial, but it isn't, because there are buggy
+ * chipsets (yes, you guessed it, by Intel and Compaq) that have no class ID.
+ */
+static int __init pci_sanity_check(struct pci_raw_ops *o)
+{
+        u32 x = 0;
+        int devfn;
+
+        if (pci_probe & PCI_NO_CHECKS)
+                return 1;
+        /* Assume Type 1 works for newer systems.
+           This handles machines that don't have anything on PCI Bus 0. */
+        if (dmi_get_year(DMI_BIOS_DATE) >= 2001)
+                return 1;
+
+        for (devfn = 0; devfn < 0x100; devfn++) {
+                if (o->read(0, 0, devfn, PCI_CLASS_DEVICE, 2, &x))
+                        continue;
+                if (x == PCI_CLASS_BRIDGE_HOST || x == PCI_CLASS_DISPLAY_VGA)
+                        return 1;
+
+                if (o->read(0, 0, devfn, PCI_VENDOR_ID, 2, &x))
+                        continue;
+                if (x == PCI_VENDOR_ID_INTEL || x == PCI_VENDOR_ID_COMPAQ)
+                        return 1;
+        }
+
+        DBG(KERN_WARNING "PCI: Sanity check failed\n");
+        return 0;
+}
+
+static int __init pci_check_type1(void)
+{
+        unsigned long flags;
+        unsigned int tmp;
+        int works = 0;
+
+        local_irq_save(flags);
+
+        outb(0x01, 0xCFB);
+        tmp = inl(0xCF8);
+        outl(0x80000000, 0xCF8);
+        if (inl(0xCF8) == 0x80000000 && pci_sanity_check(&pci_direct_conf1)) {
+                works = 1;
+        }
+        outl(tmp, 0xCF8);
+        local_irq_restore(flags);
+
+        return works;
+}
+
+static int __init pci_check_type2(void)
+{
+        unsigned long flags;
+        int works = 0;
+
+        local_irq_save(flags);
+
+        outb(0x00, 0xCFB);
+        outb(0x00, 0xCF8);
+        outb(0x00, 0xCFA);
+        if (inb(0xCF8) == 0x00 && inb(0xCFA) == 0x00 &&
+            pci_sanity_check(&pci_direct_conf2)) {
+                works = 1;
+        }
+
+        local_irq_restore(flags);
+
+        return works;
+}
+
+void __init pci_direct_init(int type)
+{
+        if (type == 0)
+                return;
+        printk(KERN_INFO "PCI: Using configuration type %d\n", type);
+        if (type == 1)
+                raw_pci_ops = &pci_direct_conf1;
+        else
+                raw_pci_ops = &pci_direct_conf2;
+}
+
+int __init pci_direct_probe(void)
+{
+        struct resource *region, *region2;
+
+        if ((pci_probe & PCI_PROBE_CONF1) == 0)
+                goto type2;
+        region = request_region(0xCF8, 8, "PCI conf1");
+        if (!region)
+                goto type2;
+
+        if (pci_check_type1())
+                return 1;
+        release_resource(region);
+
+ type2:
+        if ((pci_probe & PCI_PROBE_CONF2) == 0)
+                return 0;
+        region = request_region(0xCF8, 4, "PCI conf2");
+        if (!region)
+                return 0;
+        region2 = request_region(0xC000, 0x1000, "PCI conf2");
+        if (!region2)
+                goto fail2;
+
+        if (pci_check_type2()) {
+                printk(KERN_INFO "PCI: Using configuration type 2\n");
+                raw_pci_ops = &pci_direct_conf2;
+                return 2;
+        }
+
+        release_resource(region2);
+ fail2:
+        release_resource(region);
+        return 0;
+}