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Commit 94bb0c1a authored by David Daney's avatar David Daney Committed by Ralf Baechle
Browse files

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: default avatarDavid 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: default avatarRalf Baechle <ralf@linux-mips.org>
parent 8d662c8d

arch/mips/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ config MIPS 
	select HAVE_DMA_API_DEBUG

	select HAVE_GENERIC_HARDIRQS

	select GENERIC_IRQ_PROBE

	select HAVE_ARCH_JUMP_LABEL



menu "Machine selection"

arch/mips/include/asm/jump_label.h

0 → 100644
+48 −0
Original line number Diff line number Diff line 
/*

 * 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.

 */

#ifndef _ASM_MIPS_JUMP_LABEL_H

#define _ASM_MIPS_JUMP_LABEL_H



#include <linux/types.h>



#ifdef __KERNEL__



#define JUMP_LABEL_NOP_SIZE 4



#ifdef CONFIG_64BIT

#define WORD_INSN ".dword"

#else

#define WORD_INSN ".word"

#endif



#define JUMP_LABEL(key, label)						\

	do {								\

		asm goto("1:\tnop\n\t"					\

			"nop\n\t"					\

			".pushsection __jump_table,  \"a\"\n\t"		\

			WORD_INSN " 1b, %l[" #label "], %0\n\t"		\

			".popsection\n\t"				\

			: :  "i" (key) :  : label);			\

	} while (0)





#endif /* __KERNEL__ */



#ifdef CONFIG_64BIT

typedef u64 jump_label_t;

#else

typedef u32 jump_label_t;

#endif



struct jump_entry {

	jump_label_t code;

	jump_label_t target;

	jump_label_t key;

};



#endif /* _ASM_MIPS_JUMP_LABEL_H */

arch/mips/kernel/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -107,4 +107,6 @@ obj-$(CONFIG_MIPS_CPUFREQ) += cpufreq/ 


obj-$(CONFIG_HW_PERF_EVENTS)	+= perf_event.o



obj-$(CONFIG_JUMP_LABEL)	+= jump_label.o



CPPFLAGS_vmlinux.lds		:= $(KBUILD_CFLAGS)

arch/mips/kernel/jump_label.c

0 → 100644
+54 −0
Original line number Diff line number Diff line 
/*

 * 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 */

arch/mips/kernel/module.c

+5 −0
Original line number Diff line number Diff line
@@ -30,6 +30,8 @@ 
#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/spinlock.h>

#include <linux/jump_label.h>



#include <asm/pgtable.h>	/* MODULE_START */



struct mips_hi16 {
@@ -382,6 +384,9 @@ int module_finalize(const Elf_Ehdr *hdr, 
	const Elf_Shdr *s;

	char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;



	/* Make jump label nops. */

	jump_label_apply_nops(me);



	INIT_LIST_HEAD(&me->arch.dbe_list);

	for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {

		if (strcmp("__dbe_table", secstrings + s->sh_name) != 0)