1 files changed, 20 insertions, 4 deletions

diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index 4e84d09c9c1b..bc2d2d75f706 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -158,16 +158,24 @@
 #ifdef CONFIG_SMP
 #define ALT_SMP(instr...)                                       \
 9998:   instr
+/*
+ * Note: if you get assembler errors from ALT_UP() when building with
+ * CONFIG_THUMB2_KERNEL, you almost certainly need to use
+ * ALT_SMP( W(instr) ... )
+ */
 #define ALT_UP(instr...)                                        \
         .pushsection ".alt.smp.init", "a"                       ;\
         .long   9998b                                           ;\
-        instr                                                   ;\
+9997:   instr                                                   ;\
+        .if . - 9997b != 4                                      ;\
+                .error "ALT_UP() content must assemble to exactly 4 bytes";\
+        .endif                                                  ;\
         .popsection
 #define ALT_UP_B(label)                                 \
         .equ    up_b_offset, label - 9998b                      ;\
         .pushsection ".alt.smp.init", "a"                       ;\
         .long   9998b                                           ;\
-        b       . + up_b_offset                                 ;\
+        W(b)    . + up_b_offset                                 ;\
         .popsection
 #else
 #define ALT_SMP(instr...)
@@ -178,16 +186,24 @@
 /*
  * SMP data memory barrier
  */
-        .macro  smp_dmb
+        .macro  smp_dmb mode
 #ifdef CONFIG_SMP
 #if __LINUX_ARM_ARCH__ >= 7
+        .ifeqs "\mode","arm"
         ALT_SMP(dmb)
+        .else
+        ALT_SMP(W(dmb))
+        .endif
 #elif __LINUX_ARM_ARCH__ == 6
         ALT_SMP(mcr     p15, 0, r0, c7, c10, 5) @ dmb
 #else
 #error Incompatible SMP platform
 #endif
+        .ifeqs "\mode","arm"
         ALT_UP(nop)
+        .else
+        ALT_UP(W(nop))
+        .endif
 #endif
         .endm
 
@@ -239,7 +255,7 @@
         @ Slightly optimised to avoid incrementing the pointer twice
         usraccoff \instr, \reg, \ptr, \inc, 0, \cond, \abort
         .if     \rept == 2
-        usraccoff \instr, \reg, \ptr, \inc, 4, \cond, \abort
+        usraccoff \instr, \reg, \ptr, \inc, \inc, \cond, \abort
         .endif
 
         add\cond \ptr, #\rept * \inc