From nobody Thu Sep 18 10:16:02 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8F950C4332F for ; Thu, 8 Dec 2022 07:41:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229758AbiLHHlh (ORCPT ); Thu, 8 Dec 2022 02:41:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38830 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229513AbiLHHl2 (ORCPT ); Thu, 8 Dec 2022 02:41:28 -0500 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 016A546674 for ; Wed, 7 Dec 2022 23:41:26 -0800 (PST) Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8DxOekllZFjkg0EAA--.6239S3; Thu, 08 Dec 2022 15:41:25 +0800 (CST) Received: from linux.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8AxPuAjlZFjn8gnAA--.32821S3; Thu, 08 Dec 2022 15:41:24 +0800 (CST) From: Tiezhu Yang To: Huacai Chen , WANG Xuerui , Masami Hiramatsu Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH v8 1/4] LoongArch: Simulate branch and PC instructions Date: Thu, 8 Dec 2022 15:41:10 +0800 Message-Id: <1670485273-15717-2-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1670485273-15717-1-git-send-email-yangtiezhu@loongson.cn> References: <1670485273-15717-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf8AxPuAjlZFjn8gnAA--.32821S3 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBjvJXoW3WrWkAF4kWFyxWF1kXF1UWrg_yoWxGr1Upr W29r4kCr4DWr93CrWjqr1kXr15tr4fur43uwnxCw13CFy7uFy5GrykWr4jvFyYkw4Utry0 gayftw429F4SyaUanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUj1kv1TuYvTs0mT0YCTnIWj qI5I8CrVACY4xI64kE6c02F40Ex7xfYxn0WfASr-VFAUDa7-sFnT9fnUUIcSsGvfJTRUUU b7AYFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s 1l1IIY67AEw4v_Jr0_Jr4l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xv wVC0I7IYx2IY67AKxVW8JVW5JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwA2z4 x0Y4vEx4A2jsIE14v26r4UJVWxJr1l84ACjcxK6I8E87Iv6xkF7I0E14v26r4UJVWxJr1l e2I262IYc4CY6c8Ij28IcVAaY2xG8wAqjxCEc2xF0cIa020Ex4CE44I27wAqx4xG64xvF2 IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_JF0_Jw1lYx0Ex4A2jsIE14v26r4j6F4U McvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwCF04k20xvY0x0EwIxGrwCFx2 IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v2 6r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67 AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF04k26cxKx2IY s7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Jr 0_GrUvcSsGvfC2KfnxnUUI43ZEXa7IU8w0eJUUUUU== Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" According to LoongArch Reference Manual, simulate branch and PC instructions, this is preparation for later patch. Link: https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.= html#branch-instructions Link: https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.= html#_pcaddi_pcaddu121_pcaddu18l_pcalau12i Co-developed-by: Jinyang He Signed-off-by: Jinyang He Signed-off-by: Tiezhu Yang --- arch/loongarch/include/asm/inst.h | 12 ++++ arch/loongarch/include/asm/ptrace.h | 1 + arch/loongarch/kernel/inst.c | 123 ++++++++++++++++++++++++++++++++= ++++ 3 files changed, 136 insertions(+) diff --git a/arch/loongarch/include/asm/inst.h b/arch/loongarch/include/asm= /inst.h index 6cd994d..a91798b 100644 --- a/arch/loongarch/include/asm/inst.h +++ b/arch/loongarch/include/asm/inst.h @@ -7,6 +7,7 @@ =20 #include #include +#include =20 #define INSN_NOP 0x03400000 #define INSN_BREAK 0x002a0000 @@ -32,6 +33,7 @@ enum reg1i20_op { lu12iw_op =3D 0x0a, lu32id_op =3D 0x0b, pcaddi_op =3D 0x0c, + pcalau12i_op =3D 0x0d, pcaddu12i_op =3D 0x0e, pcaddu18i_op =3D 0x0f, }; @@ -366,6 +368,16 @@ u32 larch_insn_gen_lu12iw(enum loongarch_gpr rd, int i= mm); u32 larch_insn_gen_lu32id(enum loongarch_gpr rd, int imm); u32 larch_insn_gen_lu52id(enum loongarch_gpr rd, enum loongarch_gpr rj, in= t imm); u32 larch_insn_gen_jirl(enum loongarch_gpr rd, enum loongarch_gpr rj, unsi= gned long pc, unsigned long dest); +void simu_branch(struct pt_regs *regs, union loongarch_instruction insn); +void simu_pc(struct pt_regs *regs, union loongarch_instruction insn); + +static inline unsigned long sign_extended(unsigned long val, unsigned int = idx) +{ + if (val & (1UL << idx)) + return ~((1UL << (idx + 1)) - 1) | val; + else + return ((1UL << (idx + 1)) - 1) & val; +} =20 static inline bool signed_imm_check(long val, unsigned int bit) { diff --git a/arch/loongarch/include/asm/ptrace.h b/arch/loongarch/include/a= sm/ptrace.h index 59c4608..58596c4 100644 --- a/arch/loongarch/include/asm/ptrace.h +++ b/arch/loongarch/include/asm/ptrace.h @@ -6,6 +6,7 @@ #define _ASM_PTRACE_H =20 #include +#include #include #include =20 diff --git a/arch/loongarch/kernel/inst.c b/arch/loongarch/kernel/inst.c index 512579d..aaaf9de 100644 --- a/arch/loongarch/kernel/inst.c +++ b/arch/loongarch/kernel/inst.c @@ -165,3 +165,126 @@ u32 larch_insn_gen_jirl(enum loongarch_gpr rd, enum l= oongarch_gpr rj, unsigned l =20 return insn.word; } + +void simu_branch(struct pt_regs *regs, union loongarch_instruction insn) +{ + unsigned int imm, imm_l, imm_h, rd, rj; + unsigned long pc =3D regs->csr_era; + + if (pc & 3) { + pr_warn("%s: invalid pc 0x%lx\n", __func__, pc); + return; + } + + imm_l =3D insn.reg0i26_format.immediate_l; + imm_h =3D insn.reg0i26_format.immediate_h; + switch (insn.reg0i26_format.opcode) { + case b_op: + regs->csr_era =3D pc + sign_extended((imm_h << 16 | imm_l) << 2, 27); + return; + case bl_op: + regs->csr_era =3D pc + sign_extended((imm_h << 16 | imm_l) << 2, 27); + regs->regs[1] =3D pc + LOONGARCH_INSN_SIZE; + return; + } + + imm_l =3D insn.reg1i21_format.immediate_l; + imm_h =3D insn.reg1i21_format.immediate_h; + rj =3D insn.reg1i21_format.rj; + switch (insn.reg1i21_format.opcode) { + case beqz_op: + if (regs->regs[rj] =3D=3D 0) + regs->csr_era =3D pc + sign_extended((imm_h << 16 | imm_l) << 2, 22); + else + regs->csr_era =3D pc + LOONGARCH_INSN_SIZE; + return; + case bnez_op: + if (regs->regs[rj] !=3D 0) + regs->csr_era =3D pc + sign_extended((imm_h << 16 | imm_l) << 2, 22); + else + regs->csr_era =3D pc + LOONGARCH_INSN_SIZE; + return; + } + + imm =3D insn.reg2i16_format.immediate; + rj =3D insn.reg2i16_format.rj; + rd =3D insn.reg2i16_format.rd; + switch (insn.reg2i16_format.opcode) { + case beq_op: + if (regs->regs[rj] =3D=3D regs->regs[rd]) + regs->csr_era =3D pc + sign_extended(imm << 2, 17); + else + regs->csr_era =3D pc + LOONGARCH_INSN_SIZE; + break; + case bne_op: + if (regs->regs[rj] !=3D regs->regs[rd]) + regs->csr_era =3D pc + sign_extended(imm << 2, 17); + else + regs->csr_era =3D pc + LOONGARCH_INSN_SIZE; + break; + case blt_op: + if ((long)regs->regs[rj] < (long)regs->regs[rd]) + regs->csr_era =3D pc + sign_extended(imm << 2, 17); + else + regs->csr_era =3D pc + LOONGARCH_INSN_SIZE; + break; + case bge_op: + if ((long)regs->regs[rj] >=3D (long)regs->regs[rd]) + regs->csr_era =3D pc + sign_extended(imm << 2, 17); + else + regs->csr_era =3D pc + LOONGARCH_INSN_SIZE; + break; + case bltu_op: + if (regs->regs[rj] < regs->regs[rd]) + regs->csr_era =3D pc + sign_extended(imm << 2, 17); + else + regs->csr_era =3D pc + LOONGARCH_INSN_SIZE; + break; + case bgeu_op: + if (regs->regs[rj] >=3D regs->regs[rd]) + regs->csr_era =3D pc + sign_extended(imm << 2, 17); + else + regs->csr_era =3D pc + LOONGARCH_INSN_SIZE; + break; + case jirl_op: + regs->csr_era =3D regs->regs[rj] + sign_extended(imm << 2, 17); + regs->regs[rd] =3D pc + LOONGARCH_INSN_SIZE; + break; + default: + pr_info("%s: unknown opcode\n", __func__); + return; + } +} + +void simu_pc(struct pt_regs *regs, union loongarch_instruction insn) +{ + unsigned long pc =3D regs->csr_era; + unsigned int rd =3D insn.reg1i20_format.rd; + unsigned int imm =3D insn.reg1i20_format.immediate; + + if (pc & 3) { + pr_warn("%s: invalid pc 0x%lx\n", __func__, pc); + return; + } + + switch (insn.reg1i20_format.opcode) { + case pcaddi_op: + regs->regs[rd] =3D pc + sign_extended(imm << 2, 21); + break; + case pcaddu12i_op: + regs->regs[rd] =3D pc + sign_extended(imm << 12, 31); + break; + case pcaddu18i_op: + regs->regs[rd] =3D pc + sign_extended(imm << 18, 37); + break; + case pcalau12i_op: + regs->regs[rd] =3D pc + sign_extended(imm << 12, 31); + regs->regs[rd] &=3D ~((1 << 12) - 1); + break; + default: + pr_info("%s: unknown opcode\n", __func__); + return; + } + + regs->csr_era +=3D LOONGARCH_INSN_SIZE; +} --=20 2.1.0