ARM: smp_on_up: move inline asm ALT_SMP patching macro out of spinlock.h

Patching UP/SMP alternatives inside inline assembly blocks is useful
outside of the spinlock implementation, where it is used for sev and wfe.

This patch lifts the macro into processor.h and gives it a scarier name
to (a) avoid conflicts in the global namespace and (b) to try and deter
its usage unless you "know what you're doing". The W macro for generating
wide instructions when targetting Thumb-2 is also made available under
the name WASM, to reduce the potential for conflicts with other headers.

Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

3 files changed, 20 insertions, 11 deletions

diff --git a/arch/arm/include/asm/processor.h b/arch/arm/include/asm/processor.h
index 514a989cbd4b..26164c92fa30 100644
--- a/arch/arm/include/asm/processor.h
+++ b/arch/arm/include/asm/processor.h
@@ -22,6 +22,7 @@
 #include <asm/hw_breakpoint.h>
 #include <asm/ptrace.h>
 #include <asm/types.h>
+#include <asm/unified.h>
 
 #ifdef __KERNEL__
 #define STACK_TOP       ((current->personality & ADDR_LIMIT_32BIT) ? \
@@ -87,6 +88,17 @@ unsigned long get_wchan(struct task_struct *p);
 #define KSTK_EIP(tsk)   task_pt_regs(tsk)->ARM_pc
 #define KSTK_ESP(tsk)   task_pt_regs(tsk)->ARM_sp
 
+#ifdef CONFIG_SMP
+#define __ALT_SMP_ASM(smp, up)                                          \
+        "9998:  " smp "\n"                                              \
+        "       .pushsection \".alt.smp.init\", \"a\"\n"                \
+        "       .long   9998b\n"                                        \
+        "       " up "\n"                                               \
+        "       .popsection\n"
+#else
+#define __ALT_SMP_ASM(smp, up)  up
+#endif
+
 /*
  * Prefetching support - only ARMv5.
  */
diff --git a/arch/arm/include/asm/spinlock.h b/arch/arm/include/asm/spinlock.h
index 4f2c28060c9a..e1ce45230913 100644
--- a/arch/arm/include/asm/spinlock.h
+++ b/arch/arm/include/asm/spinlock.h
@@ -11,15 +11,7 @@
  * sev and wfe are ARMv6K extensions.  Uniprocessor ARMv6 may not have the K
  * extensions, so when running on UP, we have to patch these instructions away.
  */
-#define ALT_SMP(smp, up)                                        \
-        "9998:  " smp "\n"                                      \
-        "       .pushsection \".alt.smp.init\", \"a\"\n"        \
-        "       .long   9998b\n"                                \
-        "       " up "\n"                                       \
-        "       .popsection\n"
-
 #ifdef CONFIG_THUMB2_KERNEL
-#define SEV             ALT_SMP("sev.w", "nop.w")
 /*
  * For Thumb-2, special care is needed to ensure that the conditional WFE
  * instruction really does assemble to exactly 4 bytes (as required by
@@ -31,17 +23,18 @@
  * the assembler won't change IT instructions which are explicitly present
  * in the input.
  */
-#define WFE(cond)       ALT_SMP(                \
+#define WFE(cond)       __ALT_SMP_ASM(          \
         "it " cond "\n\t"                       \
         "wfe" cond ".n",                        \
                                                 \
         "nop.w"                                 \
 )
 #else
-#define SEV             ALT_SMP("sev", "nop")
-#define WFE(cond)       ALT_SMP("wfe" cond, "nop")
+#define WFE(cond)       __ALT_SMP_ASM("wfe" cond, "nop")
 #endif
 
+#define SEV             __ALT_SMP_ASM(WASM(sev), WASM(nop))
+
 static inline void dsb_sev(void)
 {
 #if __LINUX_ARM_ARCH__ >= 7
diff --git a/arch/arm/include/asm/unified.h b/arch/arm/include/asm/unified.h
index f5989f46b4d2..b88beaba6b4a 100644
--- a/arch/arm/include/asm/unified.h
+++ b/arch/arm/include/asm/unified.h
@@ -38,6 +38,8 @@
 #ifdef __ASSEMBLY__
 #define W(instr)        instr.w
 #define BSYM(sym)       sym + 1
+#else
+#define WASM(instr)     #instr ".w"
 #endif
 
 #else   /* !CONFIG_THUMB2_KERNEL */
@@ -50,6 +52,8 @@
 #ifdef __ASSEMBLY__
 #define W(instr)        instr
 #define BSYM(sym)       sym
+#else
+#define WASM(instr)     #instr
 #endif
 
 #endif  /* CONFIG_THUMB2_KERNEL */