1 files changed, 111 insertions, 0 deletions
diff --git a/kernel/arch/x86/pci/early.c b/kernel/arch/x86/pci/early.c
new file mode 100644
index 000000000..d1067d539
--- /dev/null
+++ b/kernel/arch/x86/pci/early.c
@@ -0,0 +1,111 @@
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <asm/pci-direct.h>
+#include <asm/io.h>
+#include <asm/pci_x86.h>
+
+/* Direct PCI access. This is used for PCI accesses in early boot before
+   the PCI subsystem works. */
+
+u32 read_pci_config(u8 bus, u8 slot, u8 func, u8 offset)
+{
+	u32 v;
+	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
+	v = inl(0xcfc);
+	return v;
+}
+
+u8 read_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset)
+{
+	u8 v;
+	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
+	v = inb(0xcfc + (offset&3));
+	return v;
+}
+
+u16 read_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset)
+{
+	u16 v;
+	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
+	v = inw(0xcfc + (offset&2));
+	return v;
+}
+
+void write_pci_config(u8 bus, u8 slot, u8 func, u8 offset,
+				    u32 val)
+{
+	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
+	outl(val, 0xcfc);
+}
+
+void write_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset, u8 val)
+{
+	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
+	outb(val, 0xcfc + (offset&3));
+}
+
+void write_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset, u16 val)
+{
+	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
+	outw(val, 0xcfc + (offset&2));
+}
+
+int early_pci_allowed(void)
+{
+	return (pci_probe & (PCI_PROBE_CONF1|PCI_PROBE_NOEARLY)) ==
+			PCI_PROBE_CONF1;
+}
+
+void early_dump_pci_device(u8 bus, u8 slot, u8 func)
+{
+	int i;
+	int j;
+	u32 val;
+
+	printk(KERN_INFO "pci 0000:%02x:%02x.%d config space:",
+	       bus, slot, func);
+
+	for (i = 0; i < 256; i += 4) {
+		if (!(i & 0x0f))
+			printk("\n  %02x:",i);
+
+		val = read_pci_config(bus, slot, func, i);
+		for (j = 0; j < 4; j++) {
+			printk(" %02x", val & 0xff);
+			val >>= 8;
+		}
+	}
+	printk("\n");
+}
+
+void early_dump_pci_devices(void)
+{
+	unsigned bus, slot, func;
+
+	if (!early_pci_allowed())
+		return;
+
+	for (bus = 0; bus < 256; bus++) {
+		for (slot = 0; slot < 32; slot++) {
+			for (func = 0; func < 8; func++) {
+				u32 class;
+				u8 type;
+
+				class = read_pci_config(bus, slot, func,
+							PCI_CLASS_REVISION);
+				if (class == 0xffffffff)
+					continue;
+
+				early_dump_pci_device(bus, slot, func);
+
+				if (func == 0) {
+					type = read_pci_config_byte(bus, slot,
+								    func,
+							       PCI_HEADER_TYPE);
+					if (!(type & 0x80))
+						break;
+				}
+			}
+		}
+	}
+}