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authorAndi Kleen <ak@suse.de>2008-01-30 13:33:21 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-30 13:33:21 +0100
commit191679fdfa63342752ff6a094a2522ae939b8d0c (patch)
treed1d3af246c10ff5201450c270fe3bb9f1bd2bd6f
parent404ee5b14b68d3cba287c2596588b83790c49f7b (diff)
x86: add noclflush option
To disable CLFLUSH usage, especially in change_page_attr(). Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--Documentation/kernel-parameters.txt2
-rw-r--r--arch/x86/kernel/cpu/common.c7
-rw-r--r--arch/x86/kernel/setup_64.c7
3 files changed, 16 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index b8fadf5f75a3..040e30a33b7c 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1191,6 +1191,8 @@ and is between 256 and 4096 characters. It is defined in the file
register save and restore. The kernel will only save
legacy floating-point registers on task switch.
+ noclflush [BUGS=X86] Don't use the CLFLUSH instruction
+
nohlt [BUGS=ARM]
no-hlt [BUGS=X86-32] Tells the kernel that the hlt
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index dfc9563fc4f0..56b7ea8e6c79 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -542,6 +542,13 @@ void __cpuinit detect_ht(struct cpuinfo_x86 *c)
}
#endif
+static __init int setup_noclflush(char *arg)
+{
+ setup_clear_cpu_cap(X86_FEATURE_CLFLSH);
+ return 1;
+}
+__setup("noclflush", setup_noclflush);
+
void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
{
char *vendor = NULL;
diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index df159520bbd2..cb9b8a90c094 100644
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -1032,6 +1032,13 @@ void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
}
+static __init int setup_noclflush(char *arg)
+{
+ setup_clear_cpu_cap(X86_FEATURE_CLFLSH);
+ return 1;
+}
+__setup("noclflush", setup_noclflush);
+
void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
{
if (c->x86_model_id[0])