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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/mips/kernel/jump_label.c | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/mips/kernel/jump_label.c')
-rw-r--r-- | arch/mips/kernel/jump_label.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/arch/mips/kernel/jump_label.c b/arch/mips/kernel/jump_label.c new file mode 100644 index 000000000..ab943927f --- /dev/null +++ b/arch/mips/kernel/jump_label.c @@ -0,0 +1,70 @@ +/* + * 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> + +/* + * Define parameters for the standard MIPS and the microMIPS jump + * instruction encoding respectively: + * + * - the ISA bit of the target, either 0 or 1 respectively, + * + * - the amount the jump target address is shifted right to fit in the + * immediate field of the machine instruction, either 2 or 1, + * + * - the mask determining the size of the jump region relative to the + * delay-slot instruction, either 256MB or 128MB, + * + * - the jump target alignment, either 4 or 2 bytes. + */ +#define J_ISA_BIT IS_ENABLED(CONFIG_CPU_MICROMIPS) +#define J_RANGE_SHIFT (2 - J_ISA_BIT) +#define J_RANGE_MASK ((1ul << (26 + J_RANGE_SHIFT)) - 1) +#define J_ALIGN_MASK ((1ul << J_RANGE_SHIFT) - 1) + +void arch_jump_label_transform(struct jump_entry *e, + enum jump_label_type type) +{ + union mips_instruction *insn_p; + union mips_instruction insn; + + insn_p = (union mips_instruction *)msk_isa16_mode(e->code); + + /* Jump only works within an aligned region its delay slot is in. */ + BUG_ON((e->target & ~J_RANGE_MASK) != ((e->code + 4) & ~J_RANGE_MASK)); + + /* Target must have the right alignment and ISA must be preserved. */ + BUG_ON((e->target & J_ALIGN_MASK) != J_ISA_BIT); + + if (type == JUMP_LABEL_JMP) { + insn.j_format.opcode = J_ISA_BIT ? mm_j32_op : j_op; + insn.j_format.target = e->target >> J_RANGE_SHIFT; + } else { + insn.word = 0; /* nop */ + } + + mutex_lock(&text_mutex); + if (IS_ENABLED(CONFIG_CPU_MICROMIPS)) { + insn_p->halfword[0] = insn.word >> 16; + insn_p->halfword[1] = insn.word; + } else + *insn_p = insn; + + flush_icache_range((unsigned long)insn_p, + (unsigned long)insn_p + sizeof(*insn_p)); + + mutex_unlock(&text_mutex); +} |