1 files changed, 147 insertions, 0 deletions
diff --git a/arch/x86/kernel/amd_nb.c b/arch/x86/kernel/amd_nb.c
new file mode 100644
index 000000000000..8f6463d8ed0d
--- /dev/null
+++ b/arch/x86/kernel/amd_nb.c
@@ -0,0 +1,147 @@
+/*
+ * Shared support code for AMD K8 northbridges and derivates.
+ * Copyright 2006 Andi Kleen, SUSE Labs. Subject to GPLv2.
+ */
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <asm/amd_nb.h>
+
+static u32 *flush_words;
+
+struct pci_device_id k8_nb_ids[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB_MISC) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_10H_NB_MISC) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_NB_MISC) },
+	{}
+};
+EXPORT_SYMBOL(k8_nb_ids);
+
+struct k8_northbridge_info k8_northbridges;
+EXPORT_SYMBOL(k8_northbridges);
+
+static struct pci_dev *next_k8_northbridge(struct pci_dev *dev)
+{
+	do {
+		dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
+		if (!dev)
+			break;
+	} while (!pci_match_id(&k8_nb_ids[0], dev));
+	return dev;
+}
+
+int cache_k8_northbridges(void)
+{
+	int i;
+	struct pci_dev *dev;
+
+	if (k8_northbridges.num)
+		return 0;
+
+	dev = NULL;
+	while ((dev = next_k8_northbridge(dev)) != NULL)
+		k8_northbridges.num++;
+
+	/* some CPU families (e.g. family 0x11) do not support GART */
+	if (boot_cpu_data.x86 == 0xf || boot_cpu_data.x86 == 0x10 ||
+	    boot_cpu_data.x86 == 0x15)
+		k8_northbridges.gart_supported = 1;
+
+	k8_northbridges.nb_misc = kmalloc((k8_northbridges.num + 1) *
+					  sizeof(void *), GFP_KERNEL);
+	if (!k8_northbridges.nb_misc)
+		return -ENOMEM;
+
+	if (!k8_northbridges.num) {
+		k8_northbridges.nb_misc[0] = NULL;
+		return 0;
+	}
+
+	if (k8_northbridges.gart_supported) {
+		flush_words = kmalloc(k8_northbridges.num * sizeof(u32),
+				      GFP_KERNEL);
+		if (!flush_words) {
+			kfree(k8_northbridges.nb_misc);
+			return -ENOMEM;
+		}
+	}
+
+	dev = NULL;
+	i = 0;
+	while ((dev = next_k8_northbridge(dev)) != NULL) {
+		k8_northbridges.nb_misc[i] = dev;
+		if (k8_northbridges.gart_supported)
+			pci_read_config_dword(dev, 0x9c, &flush_words[i++]);
+	}
+	k8_northbridges.nb_misc[i] = NULL;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cache_k8_northbridges);
+
+/* Ignores subdevice/subvendor but as far as I can figure out
+   they're useless anyways */
+int __init early_is_k8_nb(u32 device)
+{
+	struct pci_device_id *id;
+	u32 vendor = device & 0xffff;
+	device >>= 16;
+	for (id = k8_nb_ids; id->vendor; id++)
+		if (vendor == id->vendor && device == id->device)
+			return 1;
+	return 0;
+}
+
+void k8_flush_garts(void)
+{
+	int flushed, i;
+	unsigned long flags;
+	static DEFINE_SPINLOCK(gart_lock);
+
+	if (!k8_northbridges.gart_supported)
+		return;
+
+	/* Avoid races between AGP and IOMMU. In theory it's not needed
+	   but I'm not sure if the hardware won't lose flush requests
+	   when another is pending. This whole thing is so expensive anyways
+	   that it doesn't matter to serialize more. -AK */
+	spin_lock_irqsave(&gart_lock, flags);
+	flushed = 0;
+	for (i = 0; i < k8_northbridges.num; i++) {
+		pci_write_config_dword(k8_northbridges.nb_misc[i], 0x9c,
+				       flush_words[i]|1);
+		flushed++;
+	}
+	for (i = 0; i < k8_northbridges.num; i++) {
+		u32 w;
+		/* Make sure the hardware actually executed the flush*/
+		for (;;) {
+			pci_read_config_dword(k8_northbridges.nb_misc[i],
+					      0x9c, &w);
+			if (!(w & 1))
+				break;
+			cpu_relax();
+		}
+	}
+	spin_unlock_irqrestore(&gart_lock, flags);
+	if (!flushed)
+		printk("nothing to flush?\n");
+}
+EXPORT_SYMBOL_GPL(k8_flush_garts);
+
+static __init int init_k8_nbs(void)
+{
+	int err = 0;
+
+	err = cache_k8_northbridges();
+
+	if (err < 0)
+		printk(KERN_NOTICE "K8 NB: Cannot enumerate AMD northbridges.\n");
+
+	return err;
+}
+
+/* This has to go after the PCI subsystem */
+fs_initcall(init_k8_nbs);