x86, cpu, amd: Add workaround for family 16h, erratum 793

[pandora-kernel.git] / arch / x86 / kernel / cpu / amd.c

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 0bab2b1..60d4c33 100644 (file)
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -148,7 +148,6 @@ static void __cpuinit init_amd_k6(struct cpuinfo_x86 *c)
 
 static void __cpuinit amd_k7_smp_check(struct cpuinfo_x86 *c)
 {
-#ifdef CONFIG_SMP
        /* calling is from identify_secondary_cpu() ? */
        if (!c->cpu_index)
                return;
@@ -192,7 +191,6 @@ static void __cpuinit amd_k7_smp_check(struct cpuinfo_x86 *c)
 
 valid_k7:
        ;
-#endif
 }
 
 static void __cpuinit init_amd_k7(struct cpuinfo_x86 *c)
@@ -410,6 +408,16 @@ static void __cpuinit early_init_amd_mc(struct cpuinfo_x86 *c)
 
        c->x86_coreid_bits = bits;
 #endif
+
+       /* F16h erratum 793, CVE-2013-6885 */
+       if (c->x86 == 0x16 && c->x86_model <= 0xf) {
+               u64 val;
+
+               if (!rdmsrl_amd_safe(MSR_AMD64_LS_CFG, &val) &&
+                   !(val & BIT(15)))
+                       wrmsrl_amd_safe(MSR_AMD64_LS_CFG, val | BIT(15));
+       }
+
 }
 
 static void __cpuinit bsp_init_amd(struct cpuinfo_x86 *c)
@@ -471,6 +479,13 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
                        set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
        }
 #endif
+
+       /*
+        * This is only needed to tell the kernel whether to use VMCALL
+        * and VMMCALL.  VMMCALL is never executed except under virt, so
+        * we can set it unconditionally.
+        */
+       set_cpu_cap(c, X86_FEATURE_VMMCALL);
 }
 
 static void __cpuinit init_amd(struct cpuinfo_x86 *c)
@@ -571,6 +586,38 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
                }
        }
 
+       /* re-enable TopologyExtensions if switched off by BIOS */
+       if ((c->x86 == 0x15) &&
+           (c->x86_model >= 0x10) && (c->x86_model <= 0x1f) &&
+           !cpu_has(c, X86_FEATURE_TOPOEXT)) {
+               u64 val;
+
+               if (!rdmsrl_amd_safe(0xc0011005, &val)) {
+                       val |= 1ULL << 54;
+                       wrmsrl_amd_safe(0xc0011005, val);
+                       rdmsrl(0xc0011005, val);
+                       if (val & (1ULL << 54)) {
+                               set_cpu_cap(c, X86_FEATURE_TOPOEXT);
+                               printk(KERN_INFO FW_INFO "CPU: Re-enabling "
+                                 "disabled Topology Extensions Support\n");
+                       }
+               }
+       }
+
+       /*
+        * The way access filter has a performance penalty on some workloads.
+        * Disable it on the affected CPUs.
+        */
+       if ((c->x86 == 0x15) &&
+           (c->x86_model >= 0x02) && (c->x86_model < 0x20)) {
+               u64 val;
+
+               if (!rdmsrl_safe(0xc0011021, &val) && !(val & 0x1E)) {
+                       val |= 0x1E;
+                       checking_wrmsrl(0xc0011021, val);
+               }
+       }
+
        cpu_detect_cache_sizes(c);
 
        /* Multi core CPU? */