LXR linux/arch/x86/kernel/k8.c

   1/*
   2 * Shared support code for AMD K8 northbridges and derivates.
   3 * Copyright 2006 Andi Kleen, SUSE Labs. Subject to GPLv2.
   4 */
   5#include <linux/gfp.h>
   6#include <linux/types.h>
   7#include <linux/init.h>
   8#include <linux/errno.h>
   9#include <linux/module.h>
  10#include <linux/spinlock.h>
  11#include <asm/k8.h>
  12
  13int num_k8_northbridges;
  14EXPORT_SYMBOL(num_k8_northbridges);
  15
  16static u32 *flush_words;
  17
  18struct pci_device_id k8_nb_ids[] = {
  19        { PCI_DEVICE(PCI_VENDOR_ID_AMD, 0x1103) },
  20        { PCI_DEVICE(PCI_VENDOR_ID_AMD, 0x1203) },
  21        {}
  22};
  23EXPORT_SYMBOL(k8_nb_ids);
  24
  25struct pci_dev **k8_northbridges;
  26EXPORT_SYMBOL(k8_northbridges);
  27
  28static struct pci_dev *next_k8_northbridge(struct pci_dev *dev)
  29{
  30        do {
  31                dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
  32                if (!dev)
  33                        break;
  34        } while (!pci_match_id(&k8_nb_ids[0], dev));
  35        return dev;
  36}
  37
  38int cache_k8_northbridges(void)
  39{
  40        int i;
  41        struct pci_dev *dev;
  42
  43        if (num_k8_northbridges)
  44                return 0;
  45
  46        dev = NULL;
  47        while ((dev = next_k8_northbridge(dev)) != NULL)
  48                num_k8_northbridges++;
  49
  50        k8_northbridges = kmalloc((num_k8_northbridges + 1) * sizeof(void *),
  51                                  GFP_KERNEL);
  52        if (!k8_northbridges)
  53                return -ENOMEM;
  54
  55        if (!num_k8_northbridges) {
  56                k8_northbridges[0] = NULL;
  57                return 0;
  58        }
  59
  60        flush_words = kmalloc(num_k8_northbridges * sizeof(u32), GFP_KERNEL);
  61        if (!flush_words) {
  62                kfree(k8_northbridges);
  63                return -ENOMEM;
  64        }
  65
  66        dev = NULL;
  67        i = 0;
  68        while ((dev = next_k8_northbridge(dev)) != NULL) {
  69                k8_northbridges[i] = dev;
  70                pci_read_config_dword(dev, 0x9c, &flush_words[i++]);
  71        }
  72        k8_northbridges[i] = NULL;
  73        return 0;
  74}
  75EXPORT_SYMBOL_GPL(cache_k8_northbridges);
  76
  77/* Ignores subdevice/subvendor but as far as I can figure out
  78   they're useless anyways */
  79int __init early_is_k8_nb(u32 device)
  80{
  81        struct pci_device_id *id;
  82        u32 vendor = device & 0xffff;
  83        device >>= 16;
  84        for (id = k8_nb_ids; id->vendor; id++)
  85                if (vendor == id->vendor && device == id->device)
  86                        return 1;
  87        return 0;
  88}
  89
  90void k8_flush_garts(void)
  91{
  92        int flushed, i;
  93        unsigned long flags;
  94        static DEFINE_SPINLOCK(gart_lock);
  95
  96        /* Avoid races between AGP and IOMMU. In theory it's not needed
  97           but I'm not sure if the hardware won't lose flush requests
  98           when another is pending. This whole thing is so expensive anyways
  99           that it doesn't matter to serialize more. -AK */
 100        spin_lock_irqsave(&gart_lock, flags);
 101        flushed = 0;
 102        for (i = 0; i < num_k8_northbridges; i++) {
 103                pci_write_config_dword(k8_northbridges[i], 0x9c,
 104                                       flush_words[i]|1);
 105                flushed++;
 106        }
 107        for (i = 0; i < num_k8_northbridges; i++) {
 108                u32 w;
 109                /* Make sure the hardware actually executed the flush*/
 110                for (;;) {
 111                        pci_read_config_dword(k8_northbridges[i],
 112                                              0x9c, &w);
 113                        if (!(w & 1))
 114                                break;
 115                        cpu_relax();
 116                }
 117        }
 118        spin_unlock_irqrestore(&gart_lock, flags);
 119        if (!flushed)
 120                printk("nothing to flush?\n");
 121}
 122EXPORT_SYMBOL_GPL(k8_flush_garts);
 123
 124