1 files changed, 7 insertions, 42 deletions

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index fb1d3358a4af..775f10100d7f 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -169,21 +169,21 @@ static int __init x86_mpx_setup(char *s)
 __setup("nompx", x86_mpx_setup);
 
 #ifdef CONFIG_X86_64
-static int __init x86_pcid_setup(char *s)
+static int __init x86_nopcid_setup(char *s)
 {
-	/* require an exact match without trailing characters */
-	if (strlen(s))
-		return 0;
+	/* nopcid doesn't accept parameters */
+	if (s)
+		return -EINVAL;
 
 	/* do not emit a message if the feature is not present */
 	if (!boot_cpu_has(X86_FEATURE_PCID))
-		return 1;
+		return 0;
 
 	setup_clear_cpu_cap(X86_FEATURE_PCID);
 	pr_info("nopcid: PCID feature disabled\n");
-	return 1;
+	return 0;
 }
-__setup("nopcid", x86_pcid_setup);
+early_param("nopcid", x86_nopcid_setup);
 #endif
 
 static int __init x86_noinvpcid_setup(char *s)
@@ -329,38 +329,6 @@ static __always_inline void setup_smap(struct cpuinfo_x86 *c)
 	}
 }
 
-static void setup_pcid(struct cpuinfo_x86 *c)
-{
-	if (cpu_has(c, X86_FEATURE_PCID)) {
-		if (cpu_has(c, X86_FEATURE_PGE)) {
-			/*
-			 * We'd like to use cr4_set_bits_and_update_boot(),
-			 * but we can't.  CR4.PCIDE is special and can only
-			 * be set in long mode, and the early CPU init code
-			 * doesn't know this and would try to restore CR4.PCIDE
-			 * prior to entering long mode.
-			 *
-			 * Instead, we rely on the fact that hotplug, resume,
-			 * etc all fully restore CR4 before they write anything
-			 * that could have nonzero PCID bits to CR3.  CR4.PCIDE
-			 * has no effect on the page tables themselves, so we
-			 * don't need it to be restored early.
-			 */
-			cr4_set_bits(X86_CR4_PCIDE);
-		} else {
-			/*
-			 * flush_tlb_all(), as currently implemented, won't
-			 * work if PCID is on but PGE is not.  Since that
-			 * combination doesn't exist on real hardware, there's
-			 * no reason to try to fully support it, but it's
-			 * polite to avoid corrupting data if we're on
-			 * an improperly configured VM.
-			 */
-			clear_cpu_cap(c, X86_FEATURE_PCID);
-		}
-	}
-}
-
 /*
  * Protection Keys are not available in 32-bit mode.
  */
@@ -1175,9 +1143,6 @@ static void identify_cpu(struct cpuinfo_x86 *c)
 	setup_smep(c);
 	setup_smap(c);
 
-	/* Set up PCID */
-	setup_pcid(c);
-
 	/*
 	 * The vendor-specific functions might have changed features.
 	 * Now we do "generic changes."