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 c2c9ba032d46..f2d2faf4d9ae 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 f301cea5ca2d..ebdaafa866a7 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)                                 \
         }