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
  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, PCI_DEVICE_ID_AMD_K8_NB_MISC) },
  20         { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_10H_NB_MISC) },
  21         { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_11H_NB_MISC) },
  22         {}
  23 };
  24 EXPORT_SYMBOL(k8_nb_ids);
  25
  26 struct pci_dev **k8_northbridges;
  27 EXPORT_SYMBOL(k8_northbridges);
  28
  29 static struct pci_dev *next_k8_northbridge(struct pci_dev *dev)
  30 {
  31         do {
  32                 dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
  33                 if (!dev)
  34                         break;
  35         } while (!pci_match_id(&k8_nb_ids[0], dev));
  36         return dev;
  37 }
  38
  39 int cache_k8_northbridges(void)
  40 {
  41         int i;
  42         struct pci_dev *dev;
  43
  44         if (num_k8_northbridges)
  45                 return 0;
  46
  47         dev = NULL;
  48         while ((dev = next_k8_northbridge(dev)) != NULL)
  49                 num_k8_northbridges++;
  50
  51         k8_northbridges = kmalloc((num_k8_northbridges + 1) * sizeof(void *),
  52                                   GFP_KERNEL);
  53         if (!k8_northbridges)
  54                 return -ENOMEM;
  55
  56         if (!num_k8_northbridges) {
  57                 k8_northbridges[0] = NULL;
  58                 return 0;
  59         }
  60
  61         flush_words = kmalloc(num_k8_northbridges * sizeof(u32), GFP_KERNEL);
  62         if (!flush_words) {
  63                 kfree(k8_northbridges);
  64                 return -ENOMEM;
  65         }
  66
  67         dev = NULL;
  68         i = 0;
  69         while ((dev = next_k8_northbridge(dev)) != NULL) {
  70                 k8_northbridges[i] = dev;
  71                 pci_read_config_dword(dev, 0x9c, &flush_words[i++]);
  72         }
  73         k8_northbridges[i] = NULL;
  74         return 0;
  75 }
  76 EXPORT_SYMBOL_GPL(cache_k8_northbridges);
  77
  78 /* Ignores subdevice/subvendor but as far as I can figure out
  79    they're useless anyways */
  80 int __init early_is_k8_nb(u32 device)
  81 {
  82         struct pci_device_id *id;
  83         u32 vendor = device & 0xffff;
  84         device >>= 16;
  85         for (id = k8_nb_ids; id->vendor; id++)
  86                 if (vendor == id->vendor && device == id->device)
  87                         return 1;
  88         return 0;
  89 }
  90
  91 void k8_flush_garts(void)
  92 {
  93         int flushed, i;
  94         unsigned long flags;
  95         static DEFINE_SPINLOCK(gart_lock);
  96
  97         /* Avoid races between AGP and IOMMU. In theory it's not needed
  98            but I'm not sure if the hardware won't lose flush requests
  99            when another is pending. This whole thing is so expensive anyways
 100            that it doesn't matter to serialize more. -AK */
 101         spin_lock_irqsave(&gart_lock, flags);
 102         flushed = 0;
 103         for (i = 0; i < num_k8_northbridges; i++) {
 104                 pci_write_config_dword(k8_northbridges[i], 0x9c,
 105                                        flush_words[i]|1);
 106                 flushed++;
 107         }
 108         for (i = 0; i < num_k8_northbridges; i++) {
 109                 u32 w;
 110                 /* Make sure the hardware actually executed the flush*/
 111                 for (;;) {
 112                         pci_read_config_dword(k8_northbridges[i],
 113                                               0x9c, &w);
 114                         if (!(w & 1))
 115                                 break;
 116                         cpu_relax();
 117                 }
 118         }
 119         spin_unlock_irqrestore(&gart_lock, flags);
 120         if (!flushed)
 121                 printk("nothing to flush?\n");
 122 }
 123 EXPORT_SYMBOL_GPL(k8_flush_garts);
 124