Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index eeea634..90f75e5 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 #include <linux/export.h>
 #include <linux/bitops.h>
 #include <linux/elf.h>
@@ -7,6 +8,7 @@
 #include <linux/sched.h>
 #include <linux/sched/clock.h>
 #include <linux/random.h>
+#include <linux/topology.h>
 #include <asm/processor.h>
 #include <asm/apic.h>
 #include <asm/cacheinfo.h>
@@ -15,6 +17,7 @@
 #include <asm/smp.h>
 #include <asm/pci-direct.h>
 #include <asm/delay.h>
+#include <asm/debugreg.h>
 
 #ifdef CONFIG_X86_64
 # include <asm/mmconfig.h>
@@ -81,11 +84,14 @@
  *	performance at the same time..
  */
 
+#ifdef CONFIG_X86_32
 extern __visible void vide(void);
-__asm__(".globl vide\n"
+__asm__(".text\n"
+	".globl vide\n"
 	".type vide, @function\n"
 	".align 4\n"
 	"vide: ret\n");
+#endif
 
 static void init_amd_k5(struct cpuinfo_x86 *c)
 {
@@ -799,6 +805,64 @@
 	msr_set_bit(MSR_AMD64_DE_CFG, 31);
 }
 
+static bool rdrand_force;
+
+static int __init rdrand_cmdline(char *str)
+{
+	if (!str)
+		return -EINVAL;
+
+	if (!strcmp(str, "force"))
+		rdrand_force = true;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+early_param("rdrand", rdrand_cmdline);
+
+static void clear_rdrand_cpuid_bit(struct cpuinfo_x86 *c)
+{
+	/*
+	 * Saving of the MSR used to hide the RDRAND support during
+	 * suspend/resume is done by arch/x86/power/cpu.c, which is
+	 * dependent on CONFIG_PM_SLEEP.
+	 */
+	if (!IS_ENABLED(CONFIG_PM_SLEEP))
+		return;
+
+	/*
+	 * The nordrand option can clear X86_FEATURE_RDRAND, so check for
+	 * RDRAND support using the CPUID function directly.
+	 */
+	if (!(cpuid_ecx(1) & BIT(30)) || rdrand_force)
+		return;
+
+	msr_clear_bit(MSR_AMD64_CPUID_FN_1, 62);
+
+	/*
+	 * Verify that the CPUID change has occurred in case the kernel is
+	 * running virtualized and the hypervisor doesn't support the MSR.
+	 */
+	if (cpuid_ecx(1) & BIT(30)) {
+		pr_info_once("BIOS may not properly restore RDRAND after suspend, but hypervisor does not support hiding RDRAND via CPUID.\n");
+		return;
+	}
+
+	clear_cpu_cap(c, X86_FEATURE_RDRAND);
+	pr_info_once("BIOS may not properly restore RDRAND after suspend, hiding RDRAND via CPUID. Use rdrand=force to reenable.\n");
+}
+
+static void init_amd_jg(struct cpuinfo_x86 *c)
+{
+	/*
+	 * Some BIOS implementations do not restore proper RDRAND support
+	 * across suspend and resume. Check on whether to hide the RDRAND
+	 * instruction support via CPUID.
+	 */
+	clear_rdrand_cpuid_bit(c);
+}
+
 static void init_amd_bd(struct cpuinfo_x86 *c)
 {
 	u64 value;
@@ -813,16 +877,28 @@
 			wrmsrl_safe(MSR_F15H_IC_CFG, value);
 		}
 	}
+
+	/*
+	 * Some BIOS implementations do not restore proper RDRAND support
+	 * across suspend and resume. Check on whether to hide the RDRAND
+	 * instruction support via CPUID.
+	 */
+	clear_rdrand_cpuid_bit(c);
 }
 
 static void init_amd_zn(struct cpuinfo_x86 *c)
 {
 	set_cpu_cap(c, X86_FEATURE_ZEN);
+
+#ifdef CONFIG_NUMA
+	node_reclaim_distance = 32;
+#endif
+
 	/*
-	 * Fix erratum 1076: CPB feature bit not being set in CPUID. It affects
-	 * all up to and including B1.
+	 * Fix erratum 1076: CPB feature bit not being set in CPUID.
+	 * Always set it, except when running under a hypervisor.
 	 */
-	if (c->x86_model <= 1 && c->x86_stepping <= 1)
+	if (!cpu_has(c, X86_FEATURE_HYPERVISOR) && !cpu_has(c, X86_FEATURE_CPB))
 		set_cpu_cap(c, X86_FEATURE_CPB);
 }
 
@@ -854,6 +930,7 @@
 	case 0x10: init_amd_gh(c); break;
 	case 0x12: init_amd_ln(c); break;
 	case 0x15: init_amd_bd(c); break;
+	case 0x16: init_amd_jg(c); break;
 	case 0x17: init_amd_zn(c); break;
 	}
 
@@ -873,12 +950,8 @@
 	init_amd_cacheinfo(c);
 
 	if (cpu_has(c, X86_FEATURE_XMM2)) {
-		unsigned long long val;
-		int ret;
-
 		/*
-		 * A serializing LFENCE has less overhead than MFENCE, so
-		 * use it for execution serialization.  On families which
+		 * Use LFENCE for execution serialization.  On families which
 		 * don't have that MSR, LFENCE is already serializing.
 		 * msr_set_bit() uses the safe accessors, too, even if the MSR
 		 * is not present.
@@ -886,19 +959,8 @@
 		msr_set_bit(MSR_F10H_DECFG,
 			    MSR_F10H_DECFG_LFENCE_SERIALIZE_BIT);
 
-		/*
-		 * Verify that the MSR write was successful (could be running
-		 * under a hypervisor) and only then assume that LFENCE is
-		 * serializing.
-		 */
-		ret = rdmsrl_safe(MSR_F10H_DECFG, &val);
-		if (!ret && (val & MSR_F10H_DECFG_LFENCE_SERIALIZE)) {
-			/* A serializing LFENCE stops RDTSC speculation */
-			set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
-		} else {
-			/* MFENCE stops RDTSC speculation */
-			set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC);
-		}
+		/* A serializing LFENCE stops RDTSC speculation */
+		set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
 	}
 
 	/*