linux/arch/tile/kernel/jump_label.c
Zhigang Lu 65a792e84f 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>
2016-01-04 15:09:31 -05:00

65 lines
1.7 KiB
C

/*
* 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 */