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authorHeiko Carstens <heiko.carstens@de.ibm.com>2017-10-04 19:27:05 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2017-10-09 11:18:04 +0200
commit0b77d6701cf8d4eb343a83fa8d7eca81a863bb7c (patch)
treeb3254583a855788629a4c50feacef807d966fbf0 /arch/s390/lib
parent3bdf5679c9e46088a0d677e795afc92b5f77940f (diff)
downloadlinux-0b77d6701cf8d4eb343a83fa8d7eca81a863bb7c.tar.gz
s390: implement memset16, memset32 & memset64
Provide fast versions of the new memset variants. E.g. the generic
memset64 is ten times slower than the optimized version if used on a
whole page.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/lib')
-rw-r--r--arch/s390/lib/mem.S44
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/s390/lib/mem.S b/arch/s390/lib/mem.S
index 7ff79a4ff00c..f88cf6983849 100644
--- a/arch/s390/lib/mem.S
+++ b/arch/s390/lib/mem.S
@@ -126,3 +126,47 @@ ENTRY(memcpy)
 .Lmemcpy_mvc:
 	mvc	0(1,%r1),0(%r3)
 EXPORT_SYMBOL(memcpy)
+
+/*
+ * __memset16/32/64
+ *
+ * void *__memset16(uint16_t *s, uint16_t v, size_t count)
+ * void *__memset32(uint32_t *s, uint32_t v, size_t count)
+ * void *__memset64(uint64_t *s, uint64_t v, size_t count)
+ */
+.macro __MEMSET bits,bytes,insn
+ENTRY(__memset\bits)
+	ltgr	%r4,%r4
+	bzr	%r14
+	cghi	%r4,\bytes
+	je	.L__memset_exit\bits
+	aghi	%r4,-(\bytes+1)
+	srlg	%r5,%r4,8
+	ltgr	%r5,%r5
+	lgr	%r1,%r2
+	jz	.L__memset_remainder\bits
+.L__memset_loop\bits:
+	\insn	%r3,0(%r1)
+	mvc	\bytes(256-\bytes,%r1),0(%r1)
+	la	%r1,256(%r1)
+	brctg	%r5,.L__memset_loop\bits
+.L__memset_remainder\bits:
+	\insn	%r3,0(%r1)
+	larl	%r5,.L__memset_mvc\bits
+	ex	%r4,0(%r5)
+	br	%r14
+.L__memset_exit\bits:
+	\insn	%r3,0(%r2)
+	br	%r14
+.L__memset_mvc\bits:
+	mvc	\bytes(1,%r1),0(%r1)
+.endm
+
+__MEMSET 16,2,sth
+EXPORT_SYMBOL(__memset16)
+
+__MEMSET 32,4,st
+EXPORT_SYMBOL(__memset32)
+
+__MEMSET 64,8,stg
+EXPORT_SYMBOL(__memset64)