tile/jump_label: add jump label support for TILE-Gx
Add the arch-specific code to support jump label for TILE-Gx. This
code shares NOP instruction with ftrace, so we move it to a common
header file.
Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com>
Signed-off-by: Zhigang Lu <zlu@ezchip.com>
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
diff --git a/arch/tile/kernel/jump_label.c b/arch/tile/kernel/jump_label.c
new file mode 100644
index 0000000..07802d5
--- /dev/null
+++ b/arch/tile/kernel/jump_label.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2015 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ *
+ * jump label TILE-Gx support
+ */
+
+#include <linux/jump_label.h>
+#include <linux/memory.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/cpu.h>
+
+#include <asm/cacheflush.h>
+#include <asm/insn.h>
+
+#ifdef HAVE_JUMP_LABEL
+
+static void __jump_label_transform(struct jump_entry *e,
+ enum jump_label_type type)
+{
+ tilegx_bundle_bits opcode;
+ /* Operate on writable kernel text mapping. */
+ unsigned long pc_wr = ktext_writable_addr(e->code);
+
+ if (type == JUMP_LABEL_JMP)
+ opcode = tilegx_gen_branch(e->code, e->target, false);
+ else
+ opcode = NOP();
+
+ *(tilegx_bundle_bits *)pc_wr = opcode;
+ /* Make sure that above mem writes were issued towards the memory. */
+ smp_wmb();
+}
+
+void arch_jump_label_transform(struct jump_entry *e,
+ enum jump_label_type type)
+{
+ get_online_cpus();
+ mutex_lock(&text_mutex);
+
+ __jump_label_transform(e, type);
+ flush_icache_range(e->code, e->code + sizeof(tilegx_bundle_bits));
+
+ mutex_unlock(&text_mutex);
+ put_online_cpus();
+}
+
+__init_or_module void arch_jump_label_transform_static(struct jump_entry *e,
+ enum jump_label_type type)
+{
+ __jump_label_transform(e, type);
+}
+
+#endif /* HAVE_JUMP_LABEL */