1 files changed, 41 insertions, 0 deletions

diff --git a/arch/x86/kernel/amd_nb.c b/arch/x86/kernel/amd_nb.c
index 458da8509b75..6db28f17ff28 100644
--- a/arch/x86/kernel/amd_nb.c
+++ b/arch/x86/kernel/amd_nb.c
@@ -27,6 +27,8 @@ static const struct pci_device_id amd_root_ids[] = {
         {}
 };
 
+#define PCI_DEVICE_ID_AMD_CNB17H_F4     0x1704
+
 const 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) },
@@ -37,6 +39,7 @@ const struct pci_device_id amd_nb_misc_ids[] = {
         { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F3) },
         { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F3) },
         { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_DF_F3) },
+        { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CNB17H_F3) },
         {}
 };
 EXPORT_SYMBOL_GPL(amd_nb_misc_ids);
@@ -48,6 +51,7 @@ static const struct pci_device_id amd_nb_link_ids[] = {
         { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F4) },
         { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F4) },
         { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_DF_F4) },
+        { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CNB17H_F4) },
         {}
 };
 
@@ -402,11 +406,48 @@ void amd_flush_garts(void)
 }
 EXPORT_SYMBOL_GPL(amd_flush_garts);
 
+static void __fix_erratum_688(void *info)
+{
+#define MSR_AMD64_IC_CFG 0xC0011021
+
+        msr_set_bit(MSR_AMD64_IC_CFG, 3);
+        msr_set_bit(MSR_AMD64_IC_CFG, 14);
+}
+
+/* Apply erratum 688 fix so machines without a BIOS fix work. */
+static __init void fix_erratum_688(void)
+{
+        struct pci_dev *F4;
+        u32 val;
+
+        if (boot_cpu_data.x86 != 0x14)
+                return;
+
+        if (!amd_northbridges.num)
+                return;
+
+        F4 = node_to_amd_nb(0)->link;
+        if (!F4)
+                return;
+
+        if (pci_read_config_dword(F4, 0x164, &val))
+                return;
+
+        if (val & BIT(2))
+                return;
+
+        on_each_cpu(__fix_erratum_688, NULL, 0);
+
+        pr_info("x86/cpu/AMD: CPU erratum 688 worked around\n");
+}
+
 static __init int init_amd_nbs(void)
 {
         amd_cache_northbridges();
         amd_cache_gart();
 
+        fix_erratum_688();
+
         return 0;
 }