jump_label.c
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/*
* 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 */