x86, amd-nb: Cleanup AMD northbridge caching code

Support more than just the "Misc Control" part of the northbridges.
Support more flags by turning "gart_supported" into a single bit flag
that is stored in a flags member. Clean up related code by using a set
of functions (amd_nb_num(), amd_nb_has_feature() and node_to_amd_nb())
instead of accessing the NB data structures directly. Reorder the
initialization code and put the GART flush words caching in a separate
function.

Signed-off-by: Hans Rosenfeld <hans.rosenfeld@amd.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>

1 files changed, 62 insertions, 47 deletions

diff --git a/arch/x86/kernel/amd_nb.c b/arch/x86/kernel/amd_nb.c
index c46df406a2a..63c8b4f2c1a 100644
--- a/arch/x86/kernel/amd_nb.c
+++ b/arch/x86/kernel/amd_nb.c
@@ -12,74 +12,65 @@
 
 static u32 *flush_words;
 
-struct pci_device_id amd_nb_ids[] = {
+struct pci_device_id amd_nb_misc_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(amd_nb_ids);
+EXPORT_SYMBOL(amd_nb_misc_ids);
 
 struct amd_northbridge_info amd_northbridges;
 EXPORT_SYMBOL(amd_northbridges);
 
-static struct pci_dev *next_amd_northbridge(struct pci_dev *dev)
+static struct pci_dev *next_northbridge(struct pci_dev *dev,
+                                        struct pci_device_id *ids)
 {
         do {
                 dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
                 if (!dev)
                         break;
-        } while (!pci_match_id(&amd_nb_ids[0], dev));
+        } while (!pci_match_id(ids, dev));
         return dev;
 }
 
-int cache_amd_northbridges(void)
+int amd_cache_northbridges(void)
 {
-        int i;
-        struct pci_dev *dev;
+        int i = 0;
+        struct amd_northbridge *nb;
+        struct pci_dev *misc;
 
-        if (amd_northbridges.num)
+        if (amd_nb_num())
                 return 0;
 
-        dev = NULL;
-        while ((dev = next_amd_northbridge(dev)) != NULL)
-                amd_northbridges.num++;
+        misc = NULL;
+        while ((misc = next_northbridge(misc, amd_nb_misc_ids)) != NULL)
+                i++;
 
-        /* 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)
-                amd_northbridges.gart_supported = 1;
+        if (i == 0)
+                return 0;
 
-        amd_northbridges.nb_misc = kmalloc((amd_northbridges.num + 1) *
-                                          sizeof(void *), GFP_KERNEL);
-        if (!amd_northbridges.nb_misc)
+        nb = kzalloc(i * sizeof(struct amd_northbridge), GFP_KERNEL);
+        if (!nb)
                 return -ENOMEM;
 
-        if (!amd_northbridges.num) {
-                amd_northbridges.nb_misc[0] = NULL;
-                return 0;
-        }
+        amd_northbridges.nb = nb;
+        amd_northbridges.num = i;
 
-        if (amd_northbridges.gart_supported) {
-                flush_words = kmalloc(amd_northbridges.num * sizeof(u32),
-                                      GFP_KERNEL);
-                if (!flush_words) {
-                        kfree(amd_northbridges.nb_misc);
-                        return -ENOMEM;
-                }
-        }
+        misc = NULL;
+        for (i = 0; i != amd_nb_num(); i++) {
+                node_to_amd_nb(i)->misc = misc =
+                        next_northbridge(misc, amd_nb_misc_ids);
+        }
+
+        /* 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)
+                amd_northbridges.flags |= AMD_NB_GART;
 
-        dev = NULL;
-        i = 0;
-        while ((dev = next_amd_northbridge(dev)) != NULL) {
-                amd_northbridges.nb_misc[i] = dev;
-                if (amd_northbridges.gart_supported)
-                        pci_read_config_dword(dev, 0x9c, &flush_words[i++]);
-        }
-        amd_northbridges.nb_misc[i] = NULL;
         return 0;
 }
-EXPORT_SYMBOL_GPL(cache_amd_northbridges);
+EXPORT_SYMBOL_GPL(amd_cache_northbridges);
 
 /* Ignores subdevice/subvendor but as far as I can figure out
    they're useless anyways */
@@ -88,19 +79,39 @@ int __init early_is_amd_nb(u32 device)
         struct pci_device_id *id;
         u32 vendor = device & 0xffff;
         device >>= 16;
-        for (id = amd_nb_ids; id->vendor; id++)
+        for (id = amd_nb_misc_ids; id->vendor; id++)
                 if (vendor == id->vendor && device == id->device)
                         return 1;
         return 0;
 }
 
+int amd_cache_gart(void)
+{
+       int i;
+
+       if (!amd_nb_has_feature(AMD_NB_GART))
+               return 0;
+
+       flush_words = kmalloc(amd_nb_num() * sizeof(u32), GFP_KERNEL);
+       if (!flush_words) {
+               amd_northbridges.flags &= ~AMD_NB_GART;
+               return -ENOMEM;
+       }
+
+       for (i = 0; i != amd_nb_num(); i++)
+               pci_read_config_dword(node_to_amd_nb(i)->misc, 0x9c,
+                                     &flush_words[i]);
+
+       return 0;
+}
+
 void amd_flush_garts(void)
 {
         int flushed, i;
         unsigned long flags;
         static DEFINE_SPINLOCK(gart_lock);
 
-        if (!amd_northbridges.gart_supported)
+        if (!amd_nb_has_feature(AMD_NB_GART))
                 return;
 
         /* Avoid races between AGP and IOMMU. In theory it's not needed
@@ -109,16 +120,16 @@ void amd_flush_garts(void)
            that it doesn't matter to serialize more. -AK */
         spin_lock_irqsave(&gart_lock, flags);
         flushed = 0;
-        for (i = 0; i < amd_northbridges.num; i++) {
-                pci_write_config_dword(amd_northbridges.nb_misc[i], 0x9c,
-                                       flush_words[i]|1);
+        for (i = 0; i < amd_nb_num(); i++) {
+                pci_write_config_dword(node_to_amd_nb(i)->misc, 0x9c,
+                                       flush_words[i] | 1);
                 flushed++;
         }
-        for (i = 0; i < amd_northbridges.num; i++) {
+        for (i = 0; i < amd_nb_num(); i++) {
                 u32 w;
                 /* Make sure the hardware actually executed the flush*/
                 for (;;) {
-                        pci_read_config_dword(amd_northbridges.nb_misc[i],
+                        pci_read_config_dword(node_to_amd_nb(i)->misc,
                                               0x9c, &w);
                         if (!(w & 1))
                                 break;
@@ -135,11 +146,15 @@ static __init int init_amd_nbs(void)
 {
         int err = 0;
 
-        err = cache_amd_northbridges();
+        err = amd_cache_northbridges();
 
         if (err < 0)
                 printk(KERN_NOTICE "AMD NB: Cannot enumerate AMD northbridges.\n");
 
+        if (amd_cache_gart() < 0)
+                printk(KERN_NOTICE "AMD NB: Cannot initialize GART flush words, "
+                       "GART support disabled.\n");
+
         return err;
 }