[PATCH 1/4] Move pagefault_enable/disable to own include file

From: Andi Kleen
Date: Fri Oct 10 2014 - 19:25:57 EST


From: Andi Kleen <ak@xxxxxxxxxxxxxxx>

Move pagefault_enable/disable from linux/uaccess.h to
an own include file. This avoids an include loop
with asm/uaccess.h needing these inlines in its own
inlines.

linux/uaccess.h still includes the header so there
is no change for any existing users.

Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
---
arch/x86/include/asm/uaccess.h | 1 +
include/linux/pagefault.h | 39 +++++++++++++++++++++++++++++++++++++++
include/linux/uaccess.h | 34 +---------------------------------
3 files changed, 41 insertions(+), 33 deletions(-)
create mode 100644 include/linux/pagefault.h

diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 0d592e0..e50a84f 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -7,6 +7,7 @@
#include <linux/compiler.h>
#include <linux/thread_info.h>
#include <linux/string.h>
+#include <linux/pagefault.h>
#include <asm/asm.h>
#include <asm/page.h>
#include <asm/smap.h>
diff --git a/include/linux/pagefault.h b/include/linux/pagefault.h
new file mode 100644
index 0000000..f9520bd
--- /dev/null
+++ b/include/linux/pagefault.h
@@ -0,0 +1,39 @@
+#ifndef _LINUX_PAGEFAULT_H
+#define _LINUX_PAGEFAULT_H 1
+
+#include <linux/preempt.h>
+
+/*
+ * These routines enable/disable the pagefault handler in that
+ * it will not take any locks and go straight to the fixup table.
+ *
+ * They have great resemblance to the preempt_disable/enable calls
+ * and in fact they are identical; this is because currently there is
+ * no other way to make the pagefault handlers do this. So we do
+ * disable preemption but we don't necessarily care about that.
+ */
+static inline void pagefault_disable(void)
+{
+ preempt_count_inc();
+ /*
+ * make sure to have issued the store before a pagefault
+ * can hit.
+ */
+ barrier();
+}
+
+static inline void pagefault_enable(void)
+{
+#ifndef CONFIG_PREEMPT
+ /*
+ * make sure to issue those last loads/stores before enabling
+ * the pagefault handler again.
+ */
+ barrier();
+ preempt_count_dec();
+#else
+ preempt_enable();
+#endif
+}
+
+#endif
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index ecd3319..9a5e894 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -2,41 +2,9 @@
#define __LINUX_UACCESS_H__

#include <linux/preempt.h>
+#include <linux/pagefault.h>
#include <asm/uaccess.h>

-/*
- * These routines enable/disable the pagefault handler in that
- * it will not take any locks and go straight to the fixup table.
- *
- * They have great resemblance to the preempt_disable/enable calls
- * and in fact they are identical; this is because currently there is
- * no other way to make the pagefault handlers do this. So we do
- * disable preemption but we don't necessarily care about that.
- */
-static inline void pagefault_disable(void)
-{
- preempt_count_inc();
- /*
- * make sure to have issued the store before a pagefault
- * can hit.
- */
- barrier();
-}
-
-static inline void pagefault_enable(void)
-{
-#ifndef CONFIG_PREEMPT
- /*
- * make sure to issue those last loads/stores before enabling
- * the pagefault handler again.
- */
- barrier();
- preempt_count_dec();
-#else
- preempt_enable();
-#endif
-}
-
#ifndef ARCH_HAS_NOCACHE_UACCESS

static inline unsigned long __copy_from_user_inatomic_nocache(void *to,
--
1.9.3

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