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authorArnd Bergmann <arnd@arndb.de>2012-11-16 16:42:59 +0100
committerArnd Bergmann <arnd@arndb.de>2012-11-16 16:42:59 +0100
commit57260e4088894de25bb1837d529708c3ec705a69 (patch)
treee7072aed15b203197549099371db55c5d4bc3c0a /arch/sparc/include/asm/processor_64.h
parent2d4d07b97c0b774ea9ce2a2105818208d3df7241 (diff)
parent3d5e2abe6e265acc5e1fda810301243e9bac92b2 (diff)
Merge tag 'imx-fixes-rc' of git://git.pengutronix.de/git/imx/linux-2.6 into fixes
From Sascha Hauer <s.hauer@pengutronix.de>: ARM i.MX fixes for 3.7-rc * tag 'imx-fixes-rc' of git://git.pengutronix.de/git/imx/linux-2.6: ARM: imx: ehci: fix host power mask bit ARM i.MX: fix error-valued pointer dereference in clk_register_gate2() Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/sparc/include/asm/processor_64.h')
-rw-r--r--arch/sparc/include/asm/processor_64.h17
1 files changed, 16 insertions, 1 deletions
diff --git a/arch/sparc/include/asm/processor_64.h b/arch/sparc/include/asm/processor_64.h
index 4e5a483122a0..721e25f0e2ea 100644
--- a/arch/sparc/include/asm/processor_64.h
+++ b/arch/sparc/include/asm/processor_64.h
@@ -196,7 +196,22 @@ extern unsigned long get_wchan(struct task_struct *task);
#define KSTK_EIP(tsk) (task_pt_regs(tsk)->tpc)
#define KSTK_ESP(tsk) (task_pt_regs(tsk)->u_regs[UREG_FP])
-#define cpu_relax() barrier()
+/* Please see the commentary in asm/backoff.h for a description of
+ * what these instructions are doing and how they have been choosen.
+ * To make a long story short, we are trying to yield the current cpu
+ * strand during busy loops.
+ */
+#define cpu_relax() asm volatile("\n99:\n\t" \
+ "rd %%ccr, %%g0\n\t" \
+ "rd %%ccr, %%g0\n\t" \
+ "rd %%ccr, %%g0\n\t" \
+ ".section .pause_3insn_patch,\"ax\"\n\t"\
+ ".word 99b\n\t" \
+ "wr %%g0, 128, %%asr27\n\t" \
+ "nop\n\t" \
+ "nop\n\t" \
+ ".previous" \
+ ::: "memory")
/* Prefetch support. This is tuned for UltraSPARC-III and later.
* UltraSPARC-I will treat these as nops, and UltraSPARC-II has