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Commit 7aaf7b2f authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Will Deacon
Browse files

arm64/insn: add support for emitting ADR/ADRP instructions 



Add support for emitting ADR and ADRP instructions so we can switch
over our PLT generation code in a subsequent patch.

Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent d8797b12

arch/arm64/include/asm/insn.h

+8 −0
Original line number Diff line number Diff line
@@ -261,6 +261,11 @@ enum aarch64_insn_prfm_policy { 
	AARCH64_INSN_PRFM_POLICY_STRM,

};



enum aarch64_insn_adr_type {

	AARCH64_INSN_ADR_TYPE_ADRP,

	AARCH64_INSN_ADR_TYPE_ADR,

};



#define	__AARCH64_INSN_FUNCS(abbr, mask, val)	\

static __always_inline bool aarch64_insn_is_##abbr(u32 code) \

{ return (code & (mask)) == (val); } \
@@ -393,6 +398,9 @@ u32 aarch64_insn_gen_add_sub_imm(enum aarch64_insn_register dst, 
				 enum aarch64_insn_register src,

				 int imm, enum aarch64_insn_variant variant,

				 enum aarch64_insn_adsb_type type);

u32 aarch64_insn_gen_adr(unsigned long pc, unsigned long addr,

			 enum aarch64_insn_register reg,

			 enum aarch64_insn_adr_type type);

u32 aarch64_insn_gen_bitfield(enum aarch64_insn_register dst,

			      enum aarch64_insn_register src,

			      int immr, int imms,

arch/arm64/kernel/insn.c

+29 −0
Original line number Diff line number Diff line
@@ -1239,6 +1239,35 @@ u32 aarch64_insn_gen_logical_shifted_reg(enum aarch64_insn_register dst, 
	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_6, insn, shift);

}



u32 aarch64_insn_gen_adr(unsigned long pc, unsigned long addr,

			 enum aarch64_insn_register reg,

			 enum aarch64_insn_adr_type type)

{

	u32 insn;

	s32 offset;



	switch (type) {

	case AARCH64_INSN_ADR_TYPE_ADR:

		insn = aarch64_insn_get_adr_value();

		offset = addr - pc;

		break;

	case AARCH64_INSN_ADR_TYPE_ADRP:

		insn = aarch64_insn_get_adrp_value();

		offset = (addr - ALIGN_DOWN(pc, SZ_4K)) >> 12;

		break;

	default:

		pr_err("%s: unknown adr encoding %d\n", __func__, type);

		return AARCH64_BREAK_FAULT;

	}



	if (offset < -SZ_1M || offset >= SZ_1M)

		return AARCH64_BREAK_FAULT;



	insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, reg);



	return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_ADR, insn, offset);

}



/*

 * Decode the imm field of a branch, and return the byte offset as a

 * signed value (so it can be used when computing a new branch