Merge branch 'fixes-2.6.39' into for-2.6.40

2 files changed, 51 insertions, 21 deletions

diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index c2c9ba0..f2d2faf 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -165,10 +165,36 @@ extern void warn_slowpath_null(const char *file, const int line);
 #define WARN_ON_RATELIMIT(condition, state)			\
 		WARN_ON((condition) && __ratelimit(state))
 
+/*
+ * WARN_ON_SMP() is for cases that the warning is either
+ * meaningless for !SMP or may even cause failures.
+ * This is usually used for cases that we have
+ * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked()
+ * returns 0 for uniprocessor settings.
+ * It can also be used with values that are only defined
+ * on SMP:
+ *
+ * struct foo {
+ *  [...]
+ * #ifdef CONFIG_SMP
+ *	int bar;
+ * #endif
+ * };
+ *
+ * void func(struct foo *zoot)
+ * {
+ *	WARN_ON_SMP(!zoot->bar);
+ *
+ * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
+ * and should be a nop and return false for uniprocessor.
+ *
+ * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
+ * and x is true.
+ */
 #ifdef CONFIG_SMP
 # define WARN_ON_SMP(x)			WARN_ON(x)
 #else
-# define WARN_ON_SMP(x)			do { } while (0)
+# define WARN_ON_SMP(x)			({0;})
 #endif
 
 #endif
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index f301cea..ebdaafa 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -688,6 +688,28 @@
 	}
 
 /**
+ * PERCPU_INPUT - the percpu input sections
+ * @cacheline: cacheline size
+ *
+ * The core percpu section names and core symbols which do not rely
+ * directly upon load addresses.
+ *
+ * @cacheline is used to align subsections to avoid false cacheline
+ * sharing between subsections for different purposes.
+ */
+#define PERCPU_INPUT(cacheline)						\
+	VMLINUX_SYMBOL(__per_cpu_start) = .;				\
+	*(.data..percpu..first)						\
+	. = ALIGN(PAGE_SIZE);						\
+	*(.data..percpu..page_aligned)					\
+	. = ALIGN(cacheline);						\
+	*(.data..percpu..readmostly)					\
+	. = ALIGN(cacheline);						\
+	*(.data..percpu)						\
+	*(.data..percpu..shared_aligned)				\
+	VMLINUX_SYMBOL(__per_cpu_end) = .;
+
+/**
  * PERCPU_VADDR - define output section for percpu area
  * @cacheline: cacheline size
  * @vaddr: explicit base address (optional)
@@ -715,16 +737,7 @@
 	VMLINUX_SYMBOL(__per_cpu_load) = .;				\
 	.data..percpu vaddr : AT(VMLINUX_SYMBOL(__per_cpu_load)		\
 				- LOAD_OFFSET) {			\
-		VMLINUX_SYMBOL(__per_cpu_start) = .;			\
-		*(.data..percpu..first)					\
-		. = ALIGN(PAGE_SIZE);					\
-		*(.data..percpu..page_aligned)				\
-		. = ALIGN(cacheline);					\
-		*(.data..percpu..readmostly)				\
-		. = ALIGN(cacheline);					\
-		*(.data..percpu)					\
-		*(.data..percpu..shared_aligned)			\
-		VMLINUX_SYMBOL(__per_cpu_end) = .;			\
+		PERCPU_INPUT(cacheline)					\
 	} phdr								\
 	. = VMLINUX_SYMBOL(__per_cpu_load) + SIZEOF(.data..percpu);
 
@@ -744,16 +757,7 @@
 	. = ALIGN(PAGE_SIZE);						\
 	.data..percpu	: AT(ADDR(.data..percpu) - LOAD_OFFSET) {	\
 		VMLINUX_SYMBOL(__per_cpu_load) = .;			\
-		VMLINUX_SYMBOL(__per_cpu_start) = .;			\
-		*(.data..percpu..first)					\
-		. = ALIGN(PAGE_SIZE);					\
-		*(.data..percpu..page_aligned)				\
-		. = ALIGN(cacheline);					\
-		*(.data..percpu..readmostly)				\
-		. = ALIGN(cacheline);					\
-		*(.data..percpu)					\
-		*(.data..percpu..shared_aligned)			\
-		VMLINUX_SYMBOL(__per_cpu_end) = .;			\
+		PERCPU_INPUT(cacheline)					\
 	}