[Xen-changelog] [xen-unstable] x86 mtrr: Remove (noop) lock_cpu_hotplug().

[Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1275386167 -3600
# Node ID 96a7c74acd2b388819eb870e3eb4a9c65eead2a4
# Parent  2f765c9825b22c4f6d335d6ab126a69b94222f02
x86 mtrr: Remove (noop) lock_cpu_hotplug().

CPUs coming online sync themselves with current MTRR state at an
appropriate point anyway.

It's not actually possible to have a newly booted CPU immediately have
in-sync MTRR state anyway. It has to be synced up as part of normal
CPU bootstrap procedure. Which is what we do.

Signed-off-by: Keir Fraser <keir.fraser@xxxxxxxxxx>
---
 xen/arch/x86/cpu/mtrr/main.c |    6 ------
 xen/include/xen/smp.h        |    4 ----
 2 files changed, 10 deletions(-)

diff -r 2f765c9825b2 -r 96a7c74acd2b xen/arch/x86/cpu/mtrr/main.c
--- a/xen/arch/x86/cpu/mtrr/main.c      Tue Jun 01 10:40:06 2010 +0100
+++ b/xen/arch/x86/cpu/mtrr/main.c      Tue Jun 01 10:56:07 2010 +0100
@@ -365,8 +365,6 @@ int mtrr_add_page(unsigned long base, un
        error = -EINVAL;
        replace = -1;
 
-       /* No CPU hotplug when we change MTRR entries */
-       lock_cpu_hotplug();
        /*  Search for existing MTRR  */
        mutex_lock(&mtrr_mutex);
        for (i = 0; i < num_var_ranges; ++i) {
@@ -422,7 +420,6 @@ int mtrr_add_page(unsigned long base, un
        error = i;
  out:
        mutex_unlock(&mtrr_mutex);
-       unlock_cpu_hotplug();
        return error;
 }
 
@@ -511,8 +508,6 @@ int mtrr_del_page(int reg, unsigned long
                return -ENXIO;
 
        max = num_var_ranges;
-       /* No CPU hotplug when we change MTRR entries */
-       lock_cpu_hotplug();
        mutex_lock(&mtrr_mutex);
        if (reg < 0) {
                /*  Search for existing MTRR  */
@@ -553,7 +548,6 @@ int mtrr_del_page(int reg, unsigned long
        error = reg;
  out:
        mutex_unlock(&mtrr_mutex);
-       unlock_cpu_hotplug();
        return error;
 }
 /**
diff -r 2f765c9825b2 -r 96a7c74acd2b xen/include/xen/smp.h
--- a/xen/include/xen/smp.h     Tue Jun 01 10:40:06 2010 +0100
+++ b/xen/include/xen/smp.h     Tue Jun 01 10:56:07 2010 +0100
@@ -61,10 +61,6 @@ static inline int on_each_cpu(
 
 #define smp_processor_id() raw_smp_processor_id()
 
-/* No Xen contexts can be preempted by CPU hotplug. */
-#define lock_cpu_hotplug() ((void)0)
-#define unlock_cpu_hotplug() ((void)0)
-
 int alloc_cpu_id(void);
 
 #endif /* __XEN_SMP_H__ */

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