Merge tag 'x86_misc_for_6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull misc x86 updates from Dave Hansen:
 "As usual for this branch, these are super random: a compile fix for
  some newish LLVM checks and making sure a Kconfig text reference to
  'RSB' matches the normal definition:

   - Rework some CPU setup code to keep LLVM happy on 32-bit

   - Correct RSB terminology in Kconfig text"

* tag 'x86_misc_for_6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Make sure flag_is_changeable_p() is always being used
  x86/bugs: Correct RSB terminology in Kconfig

Author: torvalds

arch/x86/Kconfig

@@ -2564,15 +2564,14 @@ config MITIGATION_CALL_DEPTH_TRACKING
 	default y
 	help
 	  Compile the kernel with call depth tracking to mitigate the Intel
-	  SKL Return-Speculation-Buffer (RSB) underflow issue. The
-	  mitigation is off by default and needs to be enabled on the
-	  kernel command line via the retbleed=stuff option. For
-	  non-affected systems the overhead of this option is marginal as
-	  the call depth tracking is using run-time generated call thunks
-	  in a compiler generated padding area and call patching. This
-	  increases text size by ~5%. For non affected systems this space
-	  is unused. On affected SKL systems this results in a significant
-	  performance gain over the IBRS mitigation.
+	  SKL Return-Stack-Buffer (RSB) underflow issue. The mitigation is off
+	  by default and needs to be enabled on the kernel command line via the
+	  retbleed=stuff option. For non-affected systems the overhead of this
+	  option is marginal as the call depth tracking is using run-time
+	  generated call thunks in a compiler generated padding area and call
+	  patching. This increases text size by ~5%. For non affected systems
+	  this space is unused. On affected SKL systems this results in a
+	  significant performance gain over the IBRS mitigation.
 
 config CALL_THUNKS_DEBUG
 	bool "Enable call thunks and call depth tracking debugging"

arch/x86/include/asm/cpuid.h

@@ -6,6 +6,8 @@
 #ifndef _ASM_X86_CPUID_H
 #define _ASM_X86_CPUID_H
 
+#include <linux/types.h>
+
 #include <asm/string.h>
 
 struct cpuid_regs {
@@ -20,11 +22,11 @@ enum cpuid_regs_idx {
 };
 
 #ifdef CONFIG_X86_32
-extern int have_cpuid_p(void);
+bool have_cpuid_p(void);
 #else
-static inline int have_cpuid_p(void)
+static inline bool have_cpuid_p(void)
 {
-	return 1;
+	return true;
 }
 #endif
 static inline void native_cpuid(unsigned int *eax, unsigned int *ebx,

arch/x86/kernel/cpu/common.c

@@ -276,21 +276,13 @@ static int __init x86_noinvpcid_setup(char *s)
 }
 early_param("noinvpcid", x86_noinvpcid_setup);
 
-#ifdef CONFIG_X86_32
-static int cachesize_override = -1;
-static int disable_x86_serial_nr = 1;
-
-static int __init cachesize_setup(char *str)
-{
-	get_option(&str, &cachesize_override);
-	return 1;
-}
-__setup("cachesize=", cachesize_setup);
-
 /* Standard macro to see if a specific flag is changeable */
-static inline int flag_is_changeable_p(u32 flag)
+static inline bool flag_is_changeable_p(unsigned long flag)
 {
-	u32 f1, f2;
+	unsigned long f1, f2;
+
+	if (!IS_ENABLED(CONFIG_X86_32))
+		return true;
 
 	/*
 	 * Cyrix and IDT cpus allow disabling of CPUID
@@ -313,11 +305,22 @@ static inline int flag_is_changeable_p(u32 flag)
 		      : "=&r" (f1), "=&r" (f2)
 		      : "ir" (flag));
 
-	return ((f1^f2) & flag) != 0;
+	return (f1 ^ f2) & flag;
 }
 
+#ifdef CONFIG_X86_32
+static int cachesize_override = -1;
+static int disable_x86_serial_nr = 1;
+
+static int __init cachesize_setup(char *str)
+{
+	get_option(&str, &cachesize_override);
+	return 1;
+}
+__setup("cachesize=", cachesize_setup);
+
 /* Probe for the CPUID instruction */
-int have_cpuid_p(void)
+bool have_cpuid_p(void)
 {
 	return flag_is_changeable_p(X86_EFLAGS_ID);
 }
@@ -349,10 +352,6 @@ static int __init x86_serial_nr_setup(char *s)
 }
 __setup("serialnumber", x86_serial_nr_setup);
 #else
-static inline int flag_is_changeable_p(u32 flag)
-{
-	return 1;
-}
 static inline void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
 {
 }
@@ -1088,7 +1087,6 @@ void get_cpu_address_sizes(struct cpuinfo_x86 *c)
 
 static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
 {
-#ifdef CONFIG_X86_32
 	int i;
 
 	/*
@@ -1109,7 +1107,6 @@ static void identify_cpu_without_cpuid(struct cpuinfo_x86 *c)
 				break;
 			}
 		}
-#endif
 }
 
 #define NO_SPECULATION		BIT(0)