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authorDavid Daney <ddaney@caviumnetworks.com>2010-12-28 13:26:23 -0800
committerRalf Baechle <ralf@linux-mips.org>2011-01-18 19:30:24 +0100
commit94bb0c1ab293c298a8852e4f10c4215bad6daa9b (patch)
treee4e7dfa18bf2ffd832a97d7ab67863b1b363c6fe /arch/mips/kernel/jump_label.c
parent8d662c8d34a05e8e47deaa9e22fe770dc557c2d3 (diff)
MIPS: jump label: Add MIPS support.
In order not to be left behind, we add jump label support for MIPS. Tested on 64-bit big endian (Octeon), and 32-bit little endian (malta/qemu). Signed-off-by: David Daney <ddaney@caviumnetworks.com> To: linux-mips@linux-mips.org Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Jason Baron <jbaron@redhat.com> Patchwork: https://patchwork.linux-mips.org/patch/1923/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel/jump_label.c')
-rw-r--r--arch/mips/kernel/jump_label.c54
1 files changed, 54 insertions, 0 deletions
diff --git a/arch/mips/kernel/jump_label.c b/arch/mips/kernel/jump_label.c
new file mode 100644
index 000000000000..6001610cfe55
--- /dev/null
+++ b/arch/mips/kernel/jump_label.c
@@ -0,0 +1,54 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (c) 2010 Cavium Networks, Inc.
+ */
+
+#include <linux/jump_label.h>
+#include <linux/kernel.h>
+#include <linux/memory.h>
+#include <linux/mutex.h>
+#include <linux/types.h>
+#include <linux/cpu.h>
+
+#include <asm/cacheflush.h>
+#include <asm/inst.h>
+
+#ifdef HAVE_JUMP_LABEL
+
+#define J_RANGE_MASK ((1ul << 28) - 1)
+
+void arch_jump_label_transform(struct jump_entry *e,
+ enum jump_label_type type)
+{
+ union mips_instruction insn;
+ union mips_instruction *insn_p =
+ (union mips_instruction *)(unsigned long)e->code;
+
+ /* Jump only works within a 256MB aligned region. */
+ BUG_ON((e->target & ~J_RANGE_MASK) != (e->code & ~J_RANGE_MASK));
+
+ /* Target must have 4 byte alignment. */
+ BUG_ON((e->target & 3) != 0);
+
+ if (type == JUMP_LABEL_ENABLE) {
+ insn.j_format.opcode = j_op;
+ insn.j_format.target = (e->target & J_RANGE_MASK) >> 2;
+ } else {
+ insn.word = 0; /* nop */
+ }
+
+ get_online_cpus();
+ mutex_lock(&text_mutex);
+ *insn_p = insn;
+
+ flush_icache_range((unsigned long)insn_p,
+ (unsigned long)insn_p + sizeof(*insn_p));
+
+ mutex_unlock(&text_mutex);
+ put_online_cpus();
+}
+
+#endif /* HAVE_JUMP_LABEL */