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authorHeiko Carstens <heiko.carstens@de.ibm.com>2013-10-21 07:57:41 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2013-10-24 17:17:13 +0200
commitf84cd97e5c61fe3ce66af838dd955dee02076639 (patch)
treea3477ba33ab836d729b395741f80618ccfdab166 /arch/s390
parent0702fbf572ac5e513873628bf534da4a8a2025b4 (diff)
downloadlinux-linaro-stable-f84cd97e5c61fe3ce66af838dd955dee02076639.tar.gz
s390/percpu: make use of interlocked-access facility 1 instructions
Optimize this_cpu_* functions for 64 bit by making use of new instructions that came with the interlocked-access facility 1 (load-and-*) and the general-instructions-extension facility (asi, agsi). That way we get rid of the compare-and-swap loop in most cases. Code size reduction (defconfig, -march=z196): 11,555 bytes. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/include/asm/percpu.h125
1 files changed, 100 insertions, 25 deletions
diff --git a/arch/s390/include/asm/percpu.h b/arch/s390/include/asm/percpu.h
index 41baca870d0c..061ab45faf70 100644
--- a/arch/s390/include/asm/percpu.h
+++ b/arch/s390/include/asm/percpu.h
@@ -21,7 +21,11 @@
#define ARCH_NEEDS_WEAK_PER_CPU
#endif
-#define arch_this_cpu_to_op(pcp, val, op) \
+/*
+ * We use a compare-and-swap loop since that uses less cpu cycles than
+ * disabling and enabling interrupts like the generic variant would do.
+ */
+#define arch_this_cpu_to_op_simple(pcp, val, op) \
({ \
typedef typeof(pcp) pcp_op_T__; \
pcp_op_T__ old__, new__, prev__; \
@@ -38,30 +42,101 @@
new__; \
})
-#define this_cpu_add_1(pcp, val) arch_this_cpu_to_op(pcp, val, +)
-#define this_cpu_add_2(pcp, val) arch_this_cpu_to_op(pcp, val, +)
-#define this_cpu_add_4(pcp, val) arch_this_cpu_to_op(pcp, val, +)
-#define this_cpu_add_8(pcp, val) arch_this_cpu_to_op(pcp, val, +)
-
-#define this_cpu_add_return_1(pcp, val) arch_this_cpu_to_op(pcp, val, +)
-#define this_cpu_add_return_2(pcp, val) arch_this_cpu_to_op(pcp, val, +)
-#define this_cpu_add_return_4(pcp, val) arch_this_cpu_to_op(pcp, val, +)
-#define this_cpu_add_return_8(pcp, val) arch_this_cpu_to_op(pcp, val, +)
-
-#define this_cpu_and_1(pcp, val) arch_this_cpu_to_op(pcp, val, &)
-#define this_cpu_and_2(pcp, val) arch_this_cpu_to_op(pcp, val, &)
-#define this_cpu_and_4(pcp, val) arch_this_cpu_to_op(pcp, val, &)
-#define this_cpu_and_8(pcp, val) arch_this_cpu_to_op(pcp, val, &)
-
-#define this_cpu_or_1(pcp, val) arch_this_cpu_to_op(pcp, val, |)
-#define this_cpu_or_2(pcp, val) arch_this_cpu_to_op(pcp, val, |)
-#define this_cpu_or_4(pcp, val) arch_this_cpu_to_op(pcp, val, |)
-#define this_cpu_or_8(pcp, val) arch_this_cpu_to_op(pcp, val, |)
-
-#define this_cpu_xor_1(pcp, val) arch_this_cpu_to_op(pcp, val, ^)
-#define this_cpu_xor_2(pcp, val) arch_this_cpu_to_op(pcp, val, ^)
-#define this_cpu_xor_4(pcp, val) arch_this_cpu_to_op(pcp, val, ^)
-#define this_cpu_xor_8(pcp, val) arch_this_cpu_to_op(pcp, val, ^)
+#define this_cpu_add_1(pcp, val) arch_this_cpu_to_op_simple(pcp, val, +)
+#define this_cpu_add_2(pcp, val) arch_this_cpu_to_op_simple(pcp, val, +)
+#define this_cpu_add_return_1(pcp, val) arch_this_cpu_to_op_simple(pcp, val, +)
+#define this_cpu_add_return_2(pcp, val) arch_this_cpu_to_op_simple(pcp, val, +)
+#define this_cpu_and_1(pcp, val) arch_this_cpu_to_op_simple(pcp, val, &)
+#define this_cpu_and_2(pcp, val) arch_this_cpu_to_op_simple(pcp, val, &)
+#define this_cpu_or_1(pcp, val) arch_this_cpu_to_op_simple(pcp, val, |)
+#define this_cpu_or_2(pcp, val) arch_this_cpu_to_op_simple(pcp, val, |)
+#define this_cpu_xor_1(pcp, val) arch_this_cpu_to_op_simple(pcp, val, ^)
+#define this_cpu_xor_2(pcp, val) arch_this_cpu_to_op_simple(pcp, val, ^)
+
+#ifndef CONFIG_HAVE_MARCH_Z196_FEATURES
+
+#define this_cpu_add_4(pcp, val) arch_this_cpu_to_op_simple(pcp, val, +)
+#define this_cpu_add_8(pcp, val) arch_this_cpu_to_op_simple(pcp, val, +)
+#define this_cpu_add_return_4(pcp, val) arch_this_cpu_to_op_simple(pcp, val, +)
+#define this_cpu_add_return_8(pcp, val) arch_this_cpu_to_op_simple(pcp, val, +)
+#define this_cpu_and_4(pcp, val) arch_this_cpu_to_op_simple(pcp, val, &)
+#define this_cpu_and_8(pcp, val) arch_this_cpu_to_op_simple(pcp, val, &)
+#define this_cpu_or_4(pcp, val) arch_this_cpu_to_op_simple(pcp, val, |)
+#define this_cpu_or_8(pcp, val) arch_this_cpu_to_op_simple(pcp, val, |)
+#define this_cpu_xor_4(pcp, val) arch_this_cpu_to_op_simple(pcp, val, ^)
+#define this_cpu_xor_8(pcp, val) arch_this_cpu_to_op_simple(pcp, val, ^)
+
+#else /* CONFIG_HAVE_MARCH_Z196_FEATURES */
+
+#define arch_this_cpu_add(pcp, val, op1, op2, szcast) \
+{ \
+ typedef typeof(pcp) pcp_op_T__; \
+ pcp_op_T__ val__ = (val); \
+ pcp_op_T__ old__, *ptr__; \
+ preempt_disable(); \
+ ptr__ = __this_cpu_ptr(&(pcp)); \
+ if (__builtin_constant_p(val__) && \
+ ((szcast)val__ > -129) && ((szcast)val__ < 128)) { \
+ asm volatile( \
+ op2 " %[ptr__],%[val__]\n" \
+ : [ptr__] "+Q" (*ptr__) \
+ : [val__] "i" ((szcast)val__) \
+ : "cc"); \
+ } else { \
+ asm volatile( \
+ op1 " %[old__],%[val__],%[ptr__]\n" \
+ : [old__] "=d" (old__), [ptr__] "+Q" (*ptr__) \
+ : [val__] "d" (val__) \
+ : "cc"); \
+ } \
+ preempt_enable(); \
+}
+
+#define this_cpu_add_4(pcp, val) arch_this_cpu_add(pcp, val, "laa", "asi", int)
+#define this_cpu_add_8(pcp, val) arch_this_cpu_add(pcp, val, "laag", "agsi", long)
+
+#define arch_this_cpu_add_return(pcp, val, op) \
+({ \
+ typedef typeof(pcp) pcp_op_T__; \
+ pcp_op_T__ val__ = (val); \
+ pcp_op_T__ old__, *ptr__; \
+ preempt_disable(); \
+ ptr__ = __this_cpu_ptr(&(pcp)); \
+ asm volatile( \
+ op " %[old__],%[val__],%[ptr__]\n" \
+ : [old__] "=d" (old__), [ptr__] "+Q" (*ptr__) \
+ : [val__] "d" (val__) \
+ : "cc"); \
+ preempt_enable(); \
+ old__ + val__; \
+})
+
+#define this_cpu_add_return_4(pcp, val) arch_this_cpu_add_return(pcp, val, "laa")
+#define this_cpu_add_return_8(pcp, val) arch_this_cpu_add_return(pcp, val, "laag")
+
+#define arch_this_cpu_to_op(pcp, val, op) \
+{ \
+ typedef typeof(pcp) pcp_op_T__; \
+ pcp_op_T__ val__ = (val); \
+ pcp_op_T__ old__, *ptr__; \
+ preempt_disable(); \
+ ptr__ = __this_cpu_ptr(&(pcp)); \
+ asm volatile( \
+ op " %[old__],%[val__],%[ptr__]\n" \
+ : [old__] "=d" (old__), [ptr__] "+Q" (*ptr__) \
+ : [val__] "d" (val__) \
+ : "cc"); \
+ preempt_enable(); \
+}
+
+#define this_cpu_and_4(pcp, val) arch_this_cpu_to_op(pcp, val, "lan")
+#define this_cpu_and_8(pcp, val) arch_this_cpu_to_op(pcp, val, "lang")
+#define this_cpu_or_4(pcp, val) arch_this_cpu_to_op(pcp, val, "lao")
+#define this_cpu_or_8(pcp, val) arch_this_cpu_to_op(pcp, val, "laog")
+#define this_cpu_xor_4(pcp, val) arch_this_cpu_to_op(pcp, val, "lax")
+#define this_cpu_xor_8(pcp, val) arch_this_cpu_to_op(pcp, val, "laxg")
+
+#endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */
#define arch_this_cpu_cmpxchg(pcp, oval, nval) \
({ \