Jetpack/kernel/kernel-4.9/rt-patches/0176-rbtree-don-t-include-t...

175 lines
6.7 KiB
Diff
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

From 82ff03d9608c9c648dec1b23dd65df83b1698f44 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Fri, 23 Jun 2017 16:22:02 +0200
Subject: [PATCH 176/352] rbtree: don't include the rcu header
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
The RCU header pulls in spinlock.h and fails due not yet defined types:
|In file included from include/linux/spinlock.h:275:0,
| from include/linux/rcupdate.h:38,
| from include/linux/rbtree.h:34,
| from include/linux/rtmutex.h:17,
| from include/linux/spinlock_types.h:18,
| from kernel/bounds.c:13:
|include/linux/rwlock_rt.h:16:38: error: unknown type name rwlock_t
| extern void __lockfunc rt_write_lock(rwlock_t *rwlock);
| ^
This patch moves the required RCU function from the rcupdate.h header file into
a new header file which can be included by both users.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
include/linux/rbtree.h | 2 +-
include/linux/rcu_assign_pointer.h | 54 ++++++++++++++++++++++++++++++++++++++
include/linux/rcupdate.h | 49 +---------------------------------
3 files changed, 56 insertions(+), 49 deletions(-)
create mode 100644 include/linux/rcu_assign_pointer.h
diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h
index e585018..25c6447 100644
--- a/include/linux/rbtree.h
+++ b/include/linux/rbtree.h
@@ -31,7 +31,7 @@
#include <linux/kernel.h>
#include <linux/stddef.h>
-#include <linux/rcupdate.h>
+#include <linux/rcu_assign_pointer.h>
struct rb_node {
unsigned long __rb_parent_color;
diff --git a/include/linux/rcu_assign_pointer.h b/include/linux/rcu_assign_pointer.h
new file mode 100644
index 0000000..7066962
--- /dev/null
+++ b/include/linux/rcu_assign_pointer.h
@@ -0,0 +1,54 @@
+#ifndef __LINUX_RCU_ASSIGN_POINTER_H__
+#define __LINUX_RCU_ASSIGN_POINTER_H__
+#include <linux/compiler.h>
+#include <asm/barrier.h>
+
+/**
+ * RCU_INITIALIZER() - statically initialize an RCU-protected global variable
+ * @v: The value to statically initialize with.
+ */
+#define RCU_INITIALIZER(v) (typeof(*(v)) __force __rcu *)(v)
+
+/**
+ * rcu_assign_pointer() - assign to RCU-protected pointer
+ * @p: pointer to assign to
+ * @v: value to assign (publish)
+ *
+ * Assigns the specified value to the specified RCU-protected
+ * pointer, ensuring that any concurrent RCU readers will see
+ * any prior initialization.
+ *
+ * Inserts memory barriers on architectures that require them
+ * (which is most of them), and also prevents the compiler from
+ * reordering the code that initializes the structure after the pointer
+ * assignment. More importantly, this call documents which pointers
+ * will be dereferenced by RCU read-side code.
+ *
+ * In some special cases, you may use RCU_INIT_POINTER() instead
+ * of rcu_assign_pointer(). RCU_INIT_POINTER() is a bit faster due
+ * to the fact that it does not constrain either the CPU or the compiler.
+ * That said, using RCU_INIT_POINTER() when you should have used
+ * rcu_assign_pointer() is a very bad thing that results in
+ * impossible-to-diagnose memory corruption. So please be careful.
+ * See the RCU_INIT_POINTER() comment header for details.
+ *
+ * Note that rcu_assign_pointer() evaluates each of its arguments only
+ * once, appearances notwithstanding. One of the "extra" evaluations
+ * is in typeof() and the other visible only to sparse (__CHECKER__),
+ * neither of which actually execute the argument. As with most cpp
+ * macros, this execute-arguments-only-once property is important, so
+ * please be careful when making changes to rcu_assign_pointer() and the
+ * other macros that it invokes.
+ */
+#define rcu_assign_pointer(p, v) \
+({ \
+ uintptr_t _r_a_p__v = (uintptr_t)(v); \
+ \
+ if (__builtin_constant_p(v) && (_r_a_p__v) == (uintptr_t)NULL) \
+ WRITE_ONCE((p), (typeof(p))(_r_a_p__v)); \
+ else \
+ smp_store_release(&p, RCU_INITIALIZER((typeof(p))_r_a_p__v)); \
+ _r_a_p__v; \
+})
+
+#endif
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 00dc4a9..a5b130e 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -46,6 +46,7 @@
#include <linux/compiler.h>
#include <linux/ktime.h>
#include <linux/irqflags.h>
+#include <linux/rcu_assign_pointer.h>
#include <asm/barrier.h>
@@ -633,54 +634,6 @@ static inline void rcu_preempt_sleep_check(void)
})
/**
- * RCU_INITIALIZER() - statically initialize an RCU-protected global variable
- * @v: The value to statically initialize with.
- */
-#define RCU_INITIALIZER(v) (typeof(*(v)) __force __rcu *)(v)
-
-/**
- * rcu_assign_pointer() - assign to RCU-protected pointer
- * @p: pointer to assign to
- * @v: value to assign (publish)
- *
- * Assigns the specified value to the specified RCU-protected
- * pointer, ensuring that any concurrent RCU readers will see
- * any prior initialization.
- *
- * Inserts memory barriers on architectures that require them
- * (which is most of them), and also prevents the compiler from
- * reordering the code that initializes the structure after the pointer
- * assignment. More importantly, this call documents which pointers
- * will be dereferenced by RCU read-side code.
- *
- * In some special cases, you may use RCU_INIT_POINTER() instead
- * of rcu_assign_pointer(). RCU_INIT_POINTER() is a bit faster due
- * to the fact that it does not constrain either the CPU or the compiler.
- * That said, using RCU_INIT_POINTER() when you should have used
- * rcu_assign_pointer() is a very bad thing that results in
- * impossible-to-diagnose memory corruption. So please be careful.
- * See the RCU_INIT_POINTER() comment header for details.
- *
- * Note that rcu_assign_pointer() evaluates each of its arguments only
- * once, appearances notwithstanding. One of the "extra" evaluations
- * is in typeof() and the other visible only to sparse (__CHECKER__),
- * neither of which actually execute the argument. As with most cpp
- * macros, this execute-arguments-only-once property is important, so
- * please be careful when making changes to rcu_assign_pointer() and the
- * other macros that it invokes.
- */
-#define rcu_assign_pointer(p, v) \
-({ \
- uintptr_t _r_a_p__v = (uintptr_t)(v); \
- \
- if (__builtin_constant_p(v) && (_r_a_p__v) == (uintptr_t)NULL) \
- WRITE_ONCE((p), (typeof(p))(_r_a_p__v)); \
- else \
- smp_store_release(&p, RCU_INITIALIZER((typeof(p))_r_a_p__v)); \
- _r_a_p__v; \
-})
-
-/**
* rcu_access_pointer() - fetch RCU pointer with no dereferencing
* @p: The pointer to read
*
--
2.7.4