x86, mm: Clean up and simplify NX enablement

[firefly-linux-kernel-4.4.55.git] / arch / x86 / mm / setup_nx.c

diff --git a/arch/x86/mm/setup_nx.c b/arch/x86/mm/setup_nx.c
index 513d8ed5d2ec193aced4b43c66f008fee859d885..355818b087b52044dfc3494813260911f9f49958 100644 (file)
--- a/arch/x86/mm/setup_nx.c
+++ b/arch/x86/mm/setup_nx.c
@@ -3,10 +3,8 @@
 #include <linux/init.h>
 
 #include <asm/pgtable.h>
+#include <asm/proto.h>
 
-int nx_enabled;
-
-#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
 static int disable_nx __cpuinitdata;
 
 /*
@@ -22,48 +20,19 @@ static int __init noexec_setup(char *str)
        if (!str)
                return -EINVAL;
        if (!strncmp(str, "on", 2)) {
-               __supported_pte_mask |= _PAGE_NX;
                disable_nx = 0;
        } else if (!strncmp(str, "off", 3)) {
                disable_nx = 1;
-               __supported_pte_mask &= ~_PAGE_NX;
        }
+       x86_configure_nx();
        return 0;
 }
 early_param("noexec", noexec_setup);
-#endif
-
-#ifdef CONFIG_X86_PAE
-void __init set_nx(void)
-{
-       unsigned int v[4], l, h;
-
-       if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) {
-               cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]);
-
-               if ((v[3] & (1 << 20)) && !disable_nx) {
-                       rdmsr(MSR_EFER, l, h);
-                       l |= EFER_NX;
-                       wrmsr(MSR_EFER, l, h);
-                       nx_enabled = 1;
-                       __supported_pte_mask |= _PAGE_NX;
-               }
-       }
-}
-#else
-void set_nx(void)
-{
-}
-#endif
 
-#ifdef CONFIG_X86_64
-void __cpuinit check_efer(void)
+void __cpuinit x86_configure_nx(void)
 {
-       unsigned long efer;
-
-       rdmsrl(MSR_EFER, efer);
-       if (!(efer & EFER_NX) || disable_nx)
+       if (cpu_has_nx && !disable_nx)
+               __supported_pte_mask |= _PAGE_NX;
+       else
                __supported_pte_mask &= ~_PAGE_NX;
 }
-#endif
-