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);