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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /arch/s390/include/asm/rwonce.h
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/s390/include/asm/rwonce.h')
-rw-r--r--arch/s390/include/asm/rwonce.h31
1 files changed, 31 insertions, 0 deletions
diff --git a/arch/s390/include/asm/rwonce.h b/arch/s390/include/asm/rwonce.h
new file mode 100644
index 0000000000..91fc24520e
--- /dev/null
+++ b/arch/s390/include/asm/rwonce.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_S390_RWONCE_H
+#define __ASM_S390_RWONCE_H
+
+#include <linux/compiler_types.h>
+
+/*
+ * Use READ_ONCE_ALIGNED_128() for 128-bit block concurrent (atomic) read
+ * accesses. Note that x must be 128-bit aligned, otherwise a specification
+ * exception is generated.
+ */
+#define READ_ONCE_ALIGNED_128(x) \
+({ \
+ union { \
+ typeof(x) __x; \
+ __uint128_t val; \
+ } __u; \
+ \
+ BUILD_BUG_ON(sizeof(x) != 16); \
+ asm volatile( \
+ " lpq %[val],%[_x]\n" \
+ : [val] "=d" (__u.val) \
+ : [_x] "QS" (x) \
+ : "memory"); \
+ __u.__x; \
+})
+
+#include <asm-generic/rwonce.h>
+
+#endif /* __ASM_S390_RWONCE_H */