Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c
index 6abd835..6ce7e0a 100644
--- a/arch/x86/kernel/fpu/init.c
+++ b/arch/x86/kernel/fpu/init.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * x86 FPU boot time init code:
  */
@@ -203,12 +204,6 @@
 	 */
 
 	if (!boot_cpu_has(X86_FEATURE_FPU)) {
-		/*
-		 * Disable xsave as we do not support it if i387
-		 * emulation is enabled.
-		 */
-		setup_clear_cpu_cap(X86_FEATURE_XSAVE);
-		setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);
 		fpu_kernel_xstate_size = sizeof(struct swregs_state);
 	} else {
 		if (boot_cpu_has(X86_FEATURE_FXSR))
@@ -239,8 +234,6 @@
 
 	WARN_ON_FPU(!on_boot_cpu);
 	on_boot_cpu = 0;
-
-	WARN_ON_FPU(current->thread.fpu.initialized);
 }
 
 /*
@@ -253,17 +246,20 @@
 	char *argptr = arg;
 	int bit;
 
+#ifdef CONFIG_X86_32
 	if (cmdline_find_option_bool(boot_command_line, "no387"))
+#ifdef CONFIG_MATH_EMULATION
 		setup_clear_cpu_cap(X86_FEATURE_FPU);
+#else
+		pr_err("Option 'no387' required CONFIG_MATH_EMULATION enabled.\n");
+#endif
 
-	if (cmdline_find_option_bool(boot_command_line, "nofxsr")) {
+	if (cmdline_find_option_bool(boot_command_line, "nofxsr"))
 		setup_clear_cpu_cap(X86_FEATURE_FXSR);
-		setup_clear_cpu_cap(X86_FEATURE_FXSR_OPT);
-		setup_clear_cpu_cap(X86_FEATURE_XMM);
-	}
+#endif
 
 	if (cmdline_find_option_bool(boot_command_line, "noxsave"))
-		fpu__xstate_clear_all_cpu_caps();
+		setup_clear_cpu_cap(X86_FEATURE_XSAVE);
 
 	if (cmdline_find_option_bool(boot_command_line, "noxsaveopt"))
 		setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);