x86, amd_nb: Clarify F15h, model 30h GART and L3 support

commit 7d64ac6422092adbbdaa279ab32f9d4c90a84558 upstream.

F15h, models 0x30 and later don't have a GART. Note that. Also check
CPUID leaf 0x80000006 for L3 prescence because there are models which
don't sport an L3 cache.

Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
[ Boris: rewrite commit message, cleanup comments. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 11 insertions, 2 deletions

diff --git a/arch/x86/kernel/amd_nb.c b/arch/x86/kernel/amd_nb.c
index 3048ded1b598..59554dca96ec 100644
--- a/arch/x86/kernel/amd_nb.c
+++ b/arch/x86/kernel/amd_nb.c
@@ -20,6 +20,7 @@ const struct pci_device_id amd_nb_misc_ids[] = {
         { 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_F3) },
         { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M10H_F3) },
+        { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M30H_NB_F3) },
         { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F3) },
         {}
 };
@@ -27,6 +28,7 @@ EXPORT_SYMBOL(amd_nb_misc_ids);
 
 static const struct pci_device_id amd_nb_link_ids[] = {
         { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
+        { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M30H_NB_F4) },
         { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F4) },
         {}
 };
@@ -81,13 +83,20 @@ int amd_cache_northbridges(void)
                         next_northbridge(misc, amd_nb_misc_ids);
                 node_to_amd_nb(i)->link = link =
                         next_northbridge(link, amd_nb_link_ids);
-        }
+        }
 
+        /* GART present only on Fam15h upto model 0fh */
         if (boot_cpu_data.x86 == 0xf || boot_cpu_data.x86 == 0x10 ||
-            boot_cpu_data.x86 == 0x15)
+            (boot_cpu_data.x86 == 0x15 && boot_cpu_data.x86_model < 0x10))
                 amd_northbridges.flags |= AMD_NB_GART;
 
         /*
+         * Check for L3 cache presence.
+         */
+        if (!cpuid_edx(0x80000006))
+                return 0;
+
+        /*
          * Some CPU families support L3 Cache Index Disable. There are some
          * limitations because of E382 and E388 on family 0x10.
          */