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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /arch/s390/kernel/vdso64/getcpu.S
parentInitial commit. (diff)
downloadlinux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz
linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip
Adding upstream version 5.10.209.upstream/5.10.209
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/s390/kernel/vdso64/getcpu.S')
-rw-r--r--arch/s390/kernel/vdso64/getcpu.S31
1 files changed, 31 insertions, 0 deletions
diff --git a/arch/s390/kernel/vdso64/getcpu.S b/arch/s390/kernel/vdso64/getcpu.S
new file mode 100644
index 000000000..3c04f7328
--- /dev/null
+++ b/arch/s390/kernel/vdso64/getcpu.S
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Userland implementation of getcpu() for 64 bits processes in a
+ * s390 kernel for use in the vDSO
+ *
+ * Copyright IBM Corp. 2016
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+#include <asm/vdso.h>
+#include <asm/asm-offsets.h>
+#include <asm/dwarf.h>
+
+ .text
+ .align 4
+ .globl __kernel_getcpu
+ .type __kernel_getcpu,@function
+__kernel_getcpu:
+ CFI_STARTPROC
+ sacf 256
+ lm %r4,%r5,__VDSO_GETCPU_VAL(%r0)
+ sacf 0
+ ltgr %r2,%r2
+ jz 2f
+ st %r5,0(%r2)
+2: ltgr %r3,%r3
+ jz 3f
+ st %r4,0(%r3)
+3: lghi %r2,0
+ br %r14
+ CFI_ENDPROC
+ .size __kernel_getcpu,.-__kernel_getcpu