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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/s390/include/asm/jump_label.h
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/s390/include/asm/jump_label.h')
-rw-r--r--arch/s390/include/asm/jump_label.h55
1 files changed, 55 insertions, 0 deletions
diff --git a/arch/s390/include/asm/jump_label.h b/arch/s390/include/asm/jump_label.h
new file mode 100644
index 000000000..895f774bb
--- /dev/null
+++ b/arch/s390/include/asm/jump_label.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_S390_JUMP_LABEL_H
+#define _ASM_S390_JUMP_LABEL_H
+
+#define HAVE_JUMP_LABEL_BATCH
+
+#ifndef __ASSEMBLY__
+
+#include <linux/types.h>
+#include <linux/stringify.h>
+
+#define JUMP_LABEL_NOP_SIZE 6
+
+#ifdef CONFIG_CC_IS_CLANG
+#define JUMP_LABEL_STATIC_KEY_CONSTRAINT "i"
+#elif __GNUC__ < 9
+#define JUMP_LABEL_STATIC_KEY_CONSTRAINT "X"
+#else
+#define JUMP_LABEL_STATIC_KEY_CONSTRAINT "jdd"
+#endif
+
+/*
+ * We use a brcl 0,<offset> instruction for jump labels so it
+ * can be easily distinguished from a hotpatch generated instruction.
+ */
+static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
+{
+ asm_volatile_goto("0: brcl 0,%l[label]\n"
+ ".pushsection __jump_table,\"aw\"\n"
+ ".balign 8\n"
+ ".long 0b-.,%l[label]-.\n"
+ ".quad %0+%1-.\n"
+ ".popsection\n"
+ : : JUMP_LABEL_STATIC_KEY_CONSTRAINT (key), "i" (branch) : : label);
+ return false;
+label:
+ return true;
+}
+
+static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
+{
+ asm_volatile_goto("0: brcl 15,%l[label]\n"
+ ".pushsection __jump_table,\"aw\"\n"
+ ".balign 8\n"
+ ".long 0b-.,%l[label]-.\n"
+ ".quad %0+%1-.\n"
+ ".popsection\n"
+ : : JUMP_LABEL_STATIC_KEY_CONSTRAINT (key), "i" (branch) : : label);
+ return false;
+label:
+ return true;
+}
+
+#endif /* __ASSEMBLY__ */
+#endif