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[31.30.173.67]) by smtp.gmail.com with ESMTPSA id r17-20020aa7cfd1000000b0043ba7df7a42sm3147053edy.26.2022.08.19.07.02.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Aug 2022 07:02:54 -0700 (PDT) From: Andrew Jones To: linux-riscv@lists.infradead.org, kvm-riscv@lists.infradead.org Cc: linux-kernel@vger.kernel.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, anup@brainfault.org, mchitale@ventanamicro.com, heiko@sntech.de Subject: [PATCH 2/4] riscv: Introduce support for defining instructions Date: Fri, 19 Aug 2022 16:02:48 +0200 Message-Id: <20220819140250.3892995-3-ajones@ventanamicro.com> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220819140250.3892995-1-ajones@ventanamicro.com> References: <20220819140250.3892995-1-ajones@ventanamicro.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" When compiling with toolchains that haven't yet been taught about new instructions we need to encode them ourselves. Create a new file where support for instruction definitions will evolve. We initiate the file with a macro called INSN_R(), which implements the R-type instruction encoding. INSN_R() will use the assembler's .insn directive when available, which should give the assembler a chance to do some validation. When .insn is not available we fall back to manual encoding. Not only should using instruction encoding macros improve readability and maintainability of code over the alternative of inserting instructions directly (e.g. '.word 0xc0de'), but we should also gain potential for more optimized code after compilation because the compiler will have control over the input and output registers used. Signed-off-by: Andrew Jones Reviewed-by: Anup Patel --- arch/riscv/Kconfig | 3 ++ arch/riscv/include/asm/insn-def.h | 82 +++++++++++++++++++++++++++++++ 2 files changed, 85 insertions(+) create mode 100644 arch/riscv/include/asm/insn-def.h diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index ed66c31e4655..f8f3b316b838 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -227,6 +227,9 @@ config RISCV_DMA_NONCOHERENT select ARCH_HAS_SETUP_DMA_OPS select DMA_DIRECT_REMAP =20 +config AS_HAS_INSN + def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$= (comma) zero) + source "arch/riscv/Kconfig.socs" source "arch/riscv/Kconfig.erratas" =20 diff --git a/arch/riscv/include/asm/insn-def.h b/arch/riscv/include/asm/ins= n-def.h new file mode 100644 index 000000000000..4cd0208068dd --- /dev/null +++ b/arch/riscv/include/asm/insn-def.h @@ -0,0 +1,82 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef __ASM_INSN_DEF_H +#define __ASM_INSN_DEF_H +#include + +#define INSN_R_FUNC7_SHIFT 25 +#define INSN_R_RS2_SHIFT 20 +#define INSN_R_RS1_SHIFT 15 +#define INSN_R_FUNC3_SHIFT 12 +#define INSN_R_RD_SHIFT 7 +#define INSN_R_OPCODE_SHIFT 0 + +#ifdef __ASSEMBLY__ + +#ifdef CONFIG_AS_HAS_INSN + + .macro insn_r, opcode, func3, func7, rd, rs1, rs2 + .insn r \opcode, \func3, \func7, \rd, \rs1, \rs2 + .endm + +#else + +#include + + .macro insn_r, opcode, func3, func7, rd, rs1, rs2 + .4byte ((\opcode << INSN_R_OPCODE_SHIFT) | \ + (\func3 << INSN_R_FUNC3_SHIFT) | \ + (\func7 << INSN_R_FUNC7_SHIFT) | \ + (.L__gpr_num_\rd << INSN_R_RD_SHIFT) | \ + (.L__gpr_num_\rs1 << INSN_R_RS1_SHIFT) | \ + (.L__gpr_num_\rs2 << INSN_R_RS2_SHIFT)) + .endm + +#endif + +#define INSN_R(...) insn_r __VA_ARGS__ + +#else /* ! __ASSEMBLY__ */ + +#ifdef CONFIG_AS_HAS_INSN + +#define INSN_R(opcode, func3, func7, rd, rs1, rs2) \ + ".insn r " opcode ", " func3 ", " func7 ", " rd ", " rs1 ", " rs2 "\n" + +#else + +#include +#include + +#define DEFINE_INSN_R \ + __DEFINE_ASM_GPR_NUMS \ +" .macro insn_r, opcode, func3, func7, rd, rs1, rs2\n" \ +" .4byte ((\\opcode << " __stringify(INSN_R_OPCODE_SHIFT) ") |" \ +" (\\func3 << " __stringify(INSN_R_FUNC3_SHIFT) ") |" \ +" (\\func7 << " __stringify(INSN_R_FUNC7_SHIFT) ") |" \ +" (.L__gpr_num_\\rd << " __stringify(INSN_R_RD_SHIFT) ") |" \ +" (.L__gpr_num_\\rs1 << " __stringify(INSN_R_RS1_SHIFT) ") |" \ +" (.L__gpr_num_\\rs2 << " __stringify(INSN_R_RS2_SHIFT) "))\n" \ +" .endm\n" + +#define UNDEFINE_INSN_R \ +" .purgem insn_r\n" + +#define INSN_R(opcode, func3, func7, rd, rs1, rs2) \ + DEFINE_INSN_R \ + "insn_r " opcode ", " func3 ", " func7 ", " rd ", " rs1 ", " rs2 "\n" \ + UNDEFINE_INSN_R + +#endif + +#endif /* ! __ASSEMBLY__ */ + +#define OPCODE(v) __ASM_STR(v) +#define FUNC3(v) __ASM_STR(v) +#define FUNC7(v) __ASM_STR(v) +#define __REG(v) __ASM_STR(x ## v) +#define RD(v) __REG(v) +#define RS1(v) __REG(v) +#define RS2(v) __REG(v) + +#endif /* __ASM_INSN_DEF_H */ --=20 2.37.1