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Diffstat (limited to 'arch/x86/pci/direct.c')
-rw-r--r--arch/x86/pci/direct.c315
1 files changed, 315 insertions, 0 deletions
diff --git a/arch/x86/pci/direct.c b/arch/x86/pci/direct.c
new file mode 100644
index 000000000..15460590b
--- /dev/null
+++ b/arch/x86/pci/direct.c
@@ -0,0 +1,315 @@
+/*
+ * direct.c - Low-level direct PCI config space access
+ */
+
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/dmi.h>
+#include <asm/pci_x86.h>
+
+/*
+ * Functions for accessing PCI base (first 256 bytes) and extended
+ * (4096 bytes per PCI function) configuration space with type 1
+ * accesses.
+ */
+
+#define PCI_CONF1_ADDRESS(bus, devfn, reg) \
+ (0x80000000 | ((reg & 0xF00) << 16) | (bus << 16) \
+ | (devfn << 8) | (reg & 0xFC))
+
+static int pci_conf1_read(unsigned int seg, unsigned int bus,
+ unsigned int devfn, int reg, int len, u32 *value)
+{
+ unsigned long flags;
+
+ if (seg || (bus > 255) || (devfn > 255) || (reg > 4095)) {
+ *value = -1;
+ return -EINVAL;
+ }
+
+ raw_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;
+ }
+
+ raw_spin_unlock_irqrestore(&pci_config_lock, flags);
+
+ return 0;
+}
+
+static int pci_conf1_write(unsigned int seg, unsigned int bus,
+ unsigned int devfn, int reg, int len, u32 value)
+{
+ unsigned long flags;
+
+ if (seg || (bus > 255) || (devfn > 255) || (reg > 4095))
+ return -EINVAL;
+
+ raw_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;
+ }
+
+ raw_spin_unlock_irqrestore(&pci_config_lock, flags);
+
+ return 0;
+}
+
+#undef PCI_CONF1_ADDRESS
+
+const 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;
+
+ WARN_ON(seg);
+ 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;
+
+ raw_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);
+
+ raw_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;
+
+ WARN_ON(seg);
+ 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;
+
+ raw_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);
+
+ raw_spin_unlock_irqrestore(&pci_config_lock, flags);
+
+ return 0;
+}
+
+#undef PCI_CONF2_ADDRESS
+
+static const 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(const struct pci_raw_ops *o)
+{
+ u32 x = 0;
+ int year, 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. */
+ dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL);
+ if (year >= 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 for base access\n",
+ type);
+ if (type == 1) {
+ raw_pci_ops = &pci_direct_conf1;
+ if (raw_pci_ext_ops)
+ return;
+ if (!(pci_probe & PCI_HAS_IO_ECS))
+ return;
+ printk(KERN_INFO "PCI: Using configuration type 1 "
+ "for extended access\n");
+ raw_pci_ext_ops = &pci_direct_conf1;
+ return;
+ }
+ raw_pci_ops = &pci_direct_conf2;
+}
+
+int __init pci_direct_probe(void)
+{
+ if ((pci_probe & PCI_PROBE_CONF1) == 0)
+ goto type2;
+ if (!request_region(0xCF8, 8, "PCI conf1"))
+ goto type2;
+
+ if (pci_check_type1()) {
+ raw_pci_ops = &pci_direct_conf1;
+ port_cf9_safe = true;
+ return 1;
+ }
+ release_region(0xCF8, 8);
+
+ type2:
+ if ((pci_probe & PCI_PROBE_CONF2) == 0)
+ return 0;
+ if (!request_region(0xCF8, 4, "PCI conf2"))
+ return 0;
+ if (!request_region(0xC000, 0x1000, "PCI conf2"))
+ goto fail2;
+
+ if (pci_check_type2()) {
+ raw_pci_ops = &pci_direct_conf2;
+ port_cf9_safe = true;
+ return 2;
+ }
+
+ release_region(0xC000, 0x1000);
+ fail2:
+ release_region(0xCF8, 4);
+ return 0;
+}
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