mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-28 01:15:15 +07:00
935c2dbec4
Implement the microMIPS encoding of the J instruction for the purpose of the static keys feature, fixing a crash early on in bootstrap as the kernel is unhappy seeing the ISA bit set in jump table entries. Make sure the ISA bit correctly reflects the instruction encoding chosen for the kernel, 0 for the standard MIPS and 1 for the microMIPS encoding. Also make sure the instruction to patch is a 32-bit NOP in the microMIPS mode as by default the 16-bit short encoding is assumed Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/8516/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
57 lines
1.0 KiB
C
57 lines
1.0 KiB
C
/*
|
|
* 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
|
|
|
|
#ifdef CONFIG_CPU_MICROMIPS
|
|
#define NOP_INSN "nop32"
|
|
#else
|
|
#define NOP_INSN "nop"
|
|
#endif
|
|
|
|
static __always_inline bool arch_static_branch(struct static_key *key)
|
|
{
|
|
asm_volatile_goto("1:\t" NOP_INSN "\n\t"
|
|
"nop\n\t"
|
|
".pushsection __jump_table, \"aw\"\n\t"
|
|
WORD_INSN " 1b, %l[l_yes], %0\n\t"
|
|
".popsection\n\t"
|
|
: : "i" (key) : : l_yes);
|
|
return false;
|
|
l_yes:
|
|
return true;
|
|
}
|
|
|
|
#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 */
|