arch/x86_64/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
  13 int num_k8_northbridges;
  14 EXPORT_SYMBOL(num_k8_northbridges);
  15
  16 static u32 *flush_words;
  17
  18 struct pci_device_id k8_nb_ids[] = {
  19         { PCI_DEVICE(PCI_VENDOR_ID_AMD, 0x1103) },
  20         { PCI_DEVICE(PCI_VENDOR_ID_AMD, 0x1203) },
  21         {}
  22 };
  23 EXPORT_SYMBOL(k8_nb_ids);
  24
  25 struct pci_dev **k8_northbridges;
  26 EXPORT_SYMBOL(k8_northbridges);
  27
  28 static 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
  38 int cache_k8_northbridges(void)
  39 {
  40         int i;
  41         struct pci_dev *dev;
  42         if (num_k8_northbridges)
  43                 return 0;
  44
  45         num_k8_northbridges = 0;
  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         flush_words = kmalloc(num_k8_northbridges * sizeof(u32), GFP_KERNEL);
  56         if (!flush_words) {
  57                 kfree(k8_northbridges);
  58                 return -ENOMEM;
  59         }
  60
  61         dev = NULL;
  62         i = 0;
  63         while ((dev = next_k8_northbridge(dev)) != NULL) {
  64                 k8_northbridges[i] = dev;
  65                 pci_read_config_dword(dev, 0x9c, &flush_words[i++]);
  66         }
  67         k8_northbridges[i] = NULL;
  68         return 0;
  69 }
  70 EXPORT_SYMBOL_GPL(cache_k8_northbridges);
  71
  72 /* Ignores subdevice/subvendor but as far as I can figure out
  73    they're useless anyways */
  74 int __init early_is_k8_nb(u32 device)
  75 {
  76         struct pci_device_id *id;
  77         u32 vendor = device & 0xffff;
  78         device >>= 16;
  79         for (id = k8_nb_ids; id->vendor; id++)
  80                 if (vendor == id->vendor && device == id->device)
  81                         return 1;
  82         return 0;
  83 }
  84
  85 void k8_flush_garts(void)
  86 {
  87         int flushed, i;
  88         unsigned long flags;
  89         static DEFINE_SPINLOCK(gart_lock);
  90
  91         /* Avoid races between AGP and IOMMU. In theory it's not needed
  92            but I'm not sure if the hardware won't lose flush requests
  93            when another is pending. This whole thing is so expensive anyways
  94            that it doesn't matter to serialize more. -AK */
  95         spin_lock_irqsave(&gart_lock, flags);
  96         flushed = 0;
  97         for (i = 0; i < num_k8_northbridges; i++) {
  98                 pci_write_config_dword(k8_northbridges[i], 0x9c,
  99                                        flush_words[i]|1);
 100                 flushed++;
 101         }
 102         for (i = 0; i < num_k8_northbridges; i++) {
 103                 u32 w;
 104                 /* Make sure the hardware actually executed the flush*/
 105                 for (;;) {
 106                         pci_read_config_dword(k8_northbridges[i],
 107                                               0x9c, &w);
 108                         if (!(w & 1))
 109                                 break;
 110                         cpu_relax();
 111                 }
 112         }
 113         spin_unlock_irqrestore(&gart_lock, flags);
 114         if (!flushed)
 115                 printk("nothing to flush?\n");
 116 }
 117 EXPORT_SYMBOL_GPL(k8_flush_garts);
 118