Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git...

[linux-flexiantxendom0-3.2.10.git] / arch / powerpc / mm / mmu_context_hash64.c

diff --git a/arch/powerpc/mm/mmu_context_hash64.c b/arch/powerpc/mm/mmu_context_hash64.c
index f599f91..ca988a3 100644 (file)
--- a/arch/powerpc/mm/mmu_context_hash64.c
+++ b/arch/powerpc/mm/mmu_context_hash64.c
@@ -136,8 +136,8 @@ int use_cop(unsigned long acop, struct mm_struct *mm)
        if (!mm || !acop)
                return -EINVAL;
 
-       /* We need to make sure mm_users doesn't change */
-       down_read(&mm->mmap_sem);
+       /* The page_table_lock ensures mm_users won't change under us */
+       spin_lock(&mm->page_table_lock);
        spin_lock(mm->context.cop_lockp);
 
        if (mm->context.cop_pid == COP_PID_NONE) {
@@ -164,7 +164,7 @@ int use_cop(unsigned long acop, struct mm_struct *mm)
 
 out:
        spin_unlock(mm->context.cop_lockp);
-       up_read(&mm->mmap_sem);
+       spin_unlock(&mm->page_table_lock);
 
        return ret;
 }
@@ -185,8 +185,8 @@ void drop_cop(unsigned long acop, struct mm_struct *mm)
        if (WARN_ON_ONCE(!mm))
                return;
 
-       /* We need to make sure mm_users doesn't change */
-       down_read(&mm->mmap_sem);
+       /* The page_table_lock ensures mm_users won't change under us */
+       spin_lock(&mm->page_table_lock);
        spin_lock(mm->context.cop_lockp);
 
        mm->context.acop &= ~acop;
@@ -213,7 +213,7 @@ void drop_cop(unsigned long acop, struct mm_struct *mm)
        }
 
        spin_unlock(mm->context.cop_lockp);
-       up_read(&mm->mmap_sem);
+       spin_unlock(&mm->page_table_lock);
 }
 EXPORT_SYMBOL_GPL(drop_cop);