From: Dave Kleikamp <dave.kleikamp@oracle.com>
Date: Fri, 7 Aug 2015 21:34:03 +0000 (-0500)
Subject: sparc64: vdso: simplify cpu_relax
X-Git-Tag: v4.1.12-92~279^2^2
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=c3b28895ed346242efde62d61dc5048bb01b6d18;p=users%2Fjedix%2Flinux-maple.git

sparc64: vdso: simplify cpu_relax

Orabug: 20861959

Create a simpler cpu_relax for the VDSO object. The pause_3insn_patch
section introduces relocatable code that prevents the vdso from building.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
(cherry picked from commit edb2ed24d0e4a250ef432cf1fb7c0532817728d3)
---

diff --git a/arch/sparc/include/asm/processor_64.h b/arch/sparc/include/asm/processor_64.h
index 6924bdefe148..ebb6fea53b84 100644
--- a/arch/sparc/include/asm/processor_64.h
+++ b/arch/sparc/include/asm/processor_64.h
@@ -205,6 +205,13 @@ unsigned long get_wchan(struct task_struct *task);
  * To make a long story short, we are trying to yield the current cpu
  * strand during busy loops.
  */
+#ifdef BUILD_VDSO
+#define cpu_relax()	asm volatile("\n99:\n\t"			\
+				     "rd	%%ccr, %%g0\n\t"	\
+				     "rd	%%ccr, %%g0\n\t"	\
+				     "rd	%%ccr, %%g0\n\t"	\
+				     ::: "memory")
+#else /* ! BUILD_VDSO */
 #define cpu_relax()	asm volatile("\n99:\n\t"			\
 				     "rd	%%ccr, %%g0\n\t"	\
 				     "rd	%%ccr, %%g0\n\t"	\
@@ -216,6 +223,7 @@ unsigned long get_wchan(struct task_struct *task);
 				     "nop\n\t"				\
 				     ".previous"			\
 				     ::: "memory")
+#endif
 #define cpu_relax_lowlatency() cpu_relax()
 
 /* Prefetch support.  This is tuned for UltraSPARC-III and later.