From mboxrd@z Thu Jan 1 00:00:00 1970 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 63F4FC27C76 for ; Wed, 25 Jan 2023 14:22:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235646AbjAYOWM (ORCPT ); Wed, 25 Jan 2023 09:22:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235644AbjAYOWI (ORCPT ); Wed, 25 Jan 2023 09:22:08 -0500 Received: from mail-pl1-x632.google.com (mail-pl1-x632.google.com [IPv6:2607:f8b0:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6255A47EEF for ; Wed, 25 Jan 2023 06:22:02 -0800 (PST) Received: by mail-pl1-x632.google.com with SMTP id d3so17990887plr.10 for ; Wed, 25 Jan 2023 06:22:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sifive.com; s=google; h=references:in-reply-to:message-id:date:subject:cc:to:from:from:to :cc:subject:date:message-id:reply-to; bh=P7edCeAwjfiwkkKg0W4tIhLAZjBnv1bdBFUA+mBx+50=; b=EwaZnhUa+ekhcI4IQm40kDpmqQ91VW57Kg2SGqKJUBq+BXQ4XFzQwgtpna5MYFWjXk m8KS2maRHs4iKz+NOF7lhgcsSHaDNWzuP0c01A8zD2VH0S8PpozRaru+EVokxZBVdEuQ 0ZrBwcJ2ixaPI9EjgjVvSQjNhoJOovxiBN5VHOxemhhasziBW3F5+S/EfrjlbSrCvFji 4WUHa7OhyFYvSRnmZr9PRtqYR6OjPqL+H883VvRa6tsHv7aImWELVe67liCJHJ6/riyj T7dC+WGWz70aTYBOOnVio113pdh8ADdZo2Epci9YgnYgfT86m8lr0iQqoTZHTddY/Yaj cq1g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=references:in-reply-to:message-id:date:subject:cc:to:from :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=P7edCeAwjfiwkkKg0W4tIhLAZjBnv1bdBFUA+mBx+50=; b=B3hsMXIb2ddI5I0xlOZ7JDwiZT2XvxLUa4RWX69SU4YjXGWCW3ouL1oupH8Xc1UOqA 2LqHnWrqR4bLBXz/2g/hNr8YqKgnvs1eMDjtcoSBqfLa4MTffofOvSb3gsF6LxkQjoHO 0K868qB69Nsd335LovKOljlu5XGk78YC0RP24ffAPmUdEc9br1mU6BABqpVLphW7fvK3 IaFcg0trq328KIb/quW6ZjYaDJhJc7NNdo9dzj+DwGh3Rzp7WG1KoswDmDgAWiNGe/f0 NEh3npcWDR2WAE+qKJsy5NhXF0HyePBZVrspYRzPT1l+7DOVzEWp1D9l/bHri9Fgixg8 YSPw== X-Gm-Message-State: AFqh2kpQXc8FuA2hpuQAHXpLCTx0+AFjqtx1zuhCnbzrA+v5EzC1y+e9 UPek8VQU/EA3xrV4/42wiS8Cag== X-Google-Smtp-Source: AMrXdXtG1sIOVUuMs9I/wo6VgU4VFoE992ZnxdCDUMdsDubVbCL/9Smu69AiCEMOx3G13m1aOuX3/w== X-Received: by 2002:a17:90b:4b92:b0:229:f4e1:d4b1 with SMTP id lr18-20020a17090b4b9200b00229f4e1d4b1mr23173072pjb.22.1674656521831; Wed, 25 Jan 2023 06:22:01 -0800 (PST) Received: from hsinchu25.internal.sifive.com (59-124-168-89.hinet-ip.hinet.net. [59.124.168.89]) by smtp.gmail.com with ESMTPSA id bu11-20020a63294b000000b004a3510effa5sm3203520pgb.65.2023.01.25.06.21.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Jan 2023 06:22:01 -0800 (PST) From: Andy Chiu To: linux-riscv@lists.infradead.org, palmer@dabbelt.com, anup@brainfault.org, atishp@atishpatra.org, kvm-riscv@lists.infradead.org, kvm@vger.kernel.org Cc: vineetg@rivosinc.com, greentime.hu@sifive.com, guoren@linux.alibaba.com, Andy Chiu , Paul Walmsley , Albert Ou , Heiko Stuebner , Andrew Jones , Lad Prabhakar , Conor Dooley , Jisheng Zhang , Vincent Chen , Guo Ren , Li Zhengyu , Masahiro Yamada , Changbin Du , Richard Henderson Subject: [PATCH -next v13 10/19] riscv: Allocate user's vector context in the first-use trap Date: Wed, 25 Jan 2023 14:20:47 +0000 Message-Id: <20230125142056.18356-11-andy.chiu@sifive.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230125142056.18356-1-andy.chiu@sifive.com> References: <20230125142056.18356-1-andy.chiu@sifive.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Vector unit is disabled by default for all user processes. Thus, a process will take a trap (illegal instruction) into kernel at the first time when it uses Vector. Only after then, the kernel allocates V context and starts take care of the context for that user process. Suggested-by: Richard Henderson Link: https://lore.kernel.org/r/3923eeee-e4dc-0911-40bf-84c34aee962d@linaro.org Signed-off-by: Andy Chiu --- arch/riscv/include/asm/insn.h | 24 +++++++++ arch/riscv/include/asm/vector.h | 2 + arch/riscv/kernel/Makefile | 1 + arch/riscv/kernel/vector.c | 89 +++++++++++++++++++++++++++++++++ 4 files changed, 116 insertions(+) create mode 100644 arch/riscv/kernel/vector.c diff --git a/arch/riscv/include/asm/insn.h b/arch/riscv/include/asm/insn.h index 25ef9c0b19e7..b1ef3617881f 100644 --- a/arch/riscv/include/asm/insn.h +++ b/arch/riscv/include/asm/insn.h @@ -133,6 +133,24 @@ #define RVG_OPCODE_JALR 0x67 #define RVG_OPCODE_JAL 0x6f #define RVG_OPCODE_SYSTEM 0x73 +#define RVG_SYSTEM_CSR_OFF 20 +#define RVG_SYSTEM_CSR_MASK GENMASK(12, 0) + +/* parts of opcode for RVV */ +#define OPCODE_VECTOR 0x57 +#define LSFP_WIDTH_RVV_8 0 +#define LSFP_WIDTH_RVV_16 5 +#define LSFP_WIDTH_RVV_32 6 +#define LSFP_WIDTH_RVV_64 7 + +/* parts of opcode for RVF, RVD and RVQ */ +#define LSFP_WIDTH_OFF 12 +#define LSFP_WIDTH_MASK GENMASK(3, 0) +#define LSFP_WIDTH_FP_W 2 +#define LSFP_WIDTH_FP_D 3 +#define LSFP_WIDTH_FP_Q 4 +#define OPCODE_LOADFP 0x07 +#define OPCODE_STOREFP 0x27 /* parts of opcode for RVC*/ #define RVC_OPCODE_C0 0x0 @@ -291,6 +309,12 @@ static __always_inline bool riscv_insn_is_branch(u32 code) (RVC_X(x_, RVC_B_IMM_7_6_OPOFF, RVC_B_IMM_7_6_MASK) << RVC_B_IMM_7_6_OFF) | \ (RVC_IMM_SIGN(x_) << RVC_B_IMM_SIGN_OFF); }) +#define EXTRACT_LOAD_STORE_FP_WIDTH(x) \ + ({typeof(x) x_ = (x); RV_X(x_, LSFP_WIDTH_OFF, LSFP_WIDTH_MASK); }) + +#define EXTRACT_SYSTEM_CSR(x) \ + ({typeof(x) x_ = (x); RV_X(x_, RVG_SYSTEM_CSR_OFF, RVG_SYSTEM_CSR_MASK); }) + /* * Get the immediate from a J-type instruction. * diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h index f8a9e37c4374..7c77696d704a 100644 --- a/arch/riscv/include/asm/vector.h +++ b/arch/riscv/include/asm/vector.h @@ -19,6 +19,7 @@ #define CSR_STR(x) __ASM_STR(x) extern unsigned long riscv_vsize; +bool rvv_first_use_handler(struct pt_regs *regs); static __always_inline bool has_vector(void) { @@ -138,6 +139,7 @@ static inline void vstate_restore(struct task_struct *task, struct pt_regs; static __always_inline bool has_vector(void) { return false; } +static inline bool rvv_first_use_handler(struct pt_regs *regs) { return false; } static inline bool vstate_query(struct pt_regs *regs) { return false; } #define riscv_vsize (0) #define vstate_save(task, regs) do {} while (0) diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index 4cf303a779ab..48d345a5f326 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -55,6 +55,7 @@ obj-$(CONFIG_MMU) += vdso.o vdso/ obj-$(CONFIG_RISCV_M_MODE) += traps_misaligned.o obj-$(CONFIG_FPU) += fpu.o +obj-$(CONFIG_RISCV_ISA_V) += vector.o obj-$(CONFIG_SMP) += smpboot.o obj-$(CONFIG_SMP) += smp.o obj-$(CONFIG_SMP) += cpu_ops.o diff --git a/arch/riscv/kernel/vector.c b/arch/riscv/kernel/vector.c new file mode 100644 index 000000000000..cdd58d1c8b3c --- /dev/null +++ b/arch/riscv/kernel/vector.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2023 SiFive + * Author: Andy Chiu + */ +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +static bool insn_is_vector(u32 insn_buf) +{ + u32 opcode = insn_buf & __INSN_OPCODE_MASK; + /* + * All V-related instructions, including CSR operations are 4-Byte. So, + * do not handle if the instruction length is not 4-Byte. + */ + if (unlikely(GET_INSN_LENGTH(insn_buf) != 4)) + return false; + if (opcode == OPCODE_VECTOR) { + return true; + } else if (opcode == OPCODE_LOADFP || opcode == OPCODE_STOREFP) { + u32 width = EXTRACT_LOAD_STORE_FP_WIDTH(insn_buf); + + if (width == LSFP_WIDTH_RVV_8 || width == LSFP_WIDTH_RVV_16 || + width == LSFP_WIDTH_RVV_32 || width == LSFP_WIDTH_RVV_64) + return true; + } else if (opcode == RVG_OPCODE_SYSTEM) { + u32 csr = EXTRACT_SYSTEM_CSR(insn_buf); + + if ((csr >= CSR_VSTART && csr <= CSR_VCSR) || + (csr >= CSR_VL && csr <= CSR_VLENB)) + return true; + } + return false; +} + +int rvv_thread_zalloc(void) +{ + void *datap; + + datap = kzalloc(riscv_vsize, GFP_KERNEL); + if (!datap) + return -ENOMEM; + current->thread.vstate.datap = datap; + memset(¤t->thread.vstate, 0, offsetof(struct __riscv_v_state, + datap)); + return 0; +} + +bool rvv_first_use_handler(struct pt_regs *regs) +{ + __user u32 *epc = (u32 *)regs->epc; + u32 tval = (u32)regs->badaddr; + + /* If V has been enabled then it is not the first-use trap */ + if (vstate_query(regs)) + return false; + /* Get the instruction */ + if (!tval) { + if (__get_user(tval, epc)) + return false; + } + /* Filter out non-V instructions */ + if (!insn_is_vector(tval)) + return false; + /* Sanity check. datap should be null by the time of the first-use trap */ + WARN_ON(current->thread.vstate.datap); + /* + * Now we sure that this is a V instruction. And it executes in the + * context where VS has been off. So, try to allocate the user's V + * context and resume execution. + */ + if (rvv_thread_zalloc()) { + force_sig(SIGKILL); + return true; + } + vstate_on(regs); + return true; +} + -- 2.17.1 From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EDCD2C54E94 for ; Wed, 25 Jan 2023 14:22:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=0PpG7o/uicb+vPIwIr3oxKLMjW8CymQjCEOAprPNSJY=; b=LgOeMBe/pEfkNb MLKhf0JzyYXvah9voDXakO+3jhU8jNWDPHqjMQv3fU29R4zn+6ja8Sc56+0mnmixUg3XzZAXmhcSt qfGce6YNeyeLz+D/zJeOkewdf6wgmlEyl1pA6H3rM/J57tjuSiQS3cymlp6g+lewRr1P4tuRb54aL p8WbZsDSs88dhdRLCUdtuhYTNwSaAvO3/mtpXU9HIG/nxfAAp/SP8AhIG656lUcE+Mj4Z1DtpCRzy DHY3NAO/eRi7l0NdUYt2Mb2qRmmEaCqXewrxLB6x7MsoK5YAIaqRVToSMtTaPCa424qm3aD47R4gC HS0StbmErJ7g678KfrEA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pKgfE-007Vih-A3; Wed, 25 Jan 2023 14:22:12 +0000 Received: from mail-pj1-x1031.google.com ([2607:f8b0:4864:20::1031]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pKgfA-007VcI-QF for linux-riscv@lists.infradead.org; Wed, 25 Jan 2023 14:22:10 +0000 Received: by mail-pj1-x1031.google.com with SMTP id z9-20020a17090a468900b00226b6e7aeeaso2144389pjf.1 for ; Wed, 25 Jan 2023 06:22:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sifive.com; s=google; h=references:in-reply-to:message-id:date:subject:cc:to:from:from:to :cc:subject:date:message-id:reply-to; bh=P7edCeAwjfiwkkKg0W4tIhLAZjBnv1bdBFUA+mBx+50=; b=EwaZnhUa+ekhcI4IQm40kDpmqQ91VW57Kg2SGqKJUBq+BXQ4XFzQwgtpna5MYFWjXk m8KS2maRHs4iKz+NOF7lhgcsSHaDNWzuP0c01A8zD2VH0S8PpozRaru+EVokxZBVdEuQ 0ZrBwcJ2ixaPI9EjgjVvSQjNhoJOovxiBN5VHOxemhhasziBW3F5+S/EfrjlbSrCvFji 4WUHa7OhyFYvSRnmZr9PRtqYR6OjPqL+H883VvRa6tsHv7aImWELVe67liCJHJ6/riyj T7dC+WGWz70aTYBOOnVio113pdh8ADdZo2Epci9YgnYgfT86m8lr0iQqoTZHTddY/Yaj cq1g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=references:in-reply-to:message-id:date:subject:cc:to:from :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=P7edCeAwjfiwkkKg0W4tIhLAZjBnv1bdBFUA+mBx+50=; b=hS86wz/T9kkKKYwJaxi3HnA/UVuapqW0ukejvWpXZzHkEXuh0QVJAV/8JWpVX5urI8 as7uLEzqsdz/gnf5GgvfOq7MAuE134ifu5qOY4VSp7PMEoovQ70P37ULPOC7V4CmX93U 0vPuJgrzF1QPQncHSdiK5aB8fK44kHcIOSKkiRYqGH39Vy8xCG/oiu7iuSXKX28npXLw 2SJRCI7GEETexmxbvgoPuRshgAc4Izck+MsDwD3VEEGqeObWHlQbmdkNwBdlL/vTLJS5 jUAVplGPaZo3uJPQbC2w9y6oxN6Me0tVFS+Ykmw0vpkf87E55AKKtB/VOSyzXyLua4+N 862w== X-Gm-Message-State: AFqh2kpwl7gtvkS/kCeUC3IygpJuzY0mJ3lGOUuFxPKJar9iizeoXB8x P47c+zcfujOT9HCLk5ID53nVKosao3WltvsclvlM14unLMtZPJMt1iQz65Wu/sS+SY+QJYKdwJF 2Pu9csm5L/on1oXkhmMxtottnBXuIQZw6WyenpZw5HQqBgjDRmSeW0zlCUss0gLCP7k7yCUcXFB cj98xx9B3V1Q== X-Google-Smtp-Source: AMrXdXtG1sIOVUuMs9I/wo6VgU4VFoE992ZnxdCDUMdsDubVbCL/9Smu69AiCEMOx3G13m1aOuX3/w== X-Received: by 2002:a17:90b:4b92:b0:229:f4e1:d4b1 with SMTP id lr18-20020a17090b4b9200b00229f4e1d4b1mr23173072pjb.22.1674656521831; Wed, 25 Jan 2023 06:22:01 -0800 (PST) Received: from hsinchu25.internal.sifive.com (59-124-168-89.hinet-ip.hinet.net. [59.124.168.89]) by smtp.gmail.com with ESMTPSA id bu11-20020a63294b000000b004a3510effa5sm3203520pgb.65.2023.01.25.06.21.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Jan 2023 06:22:01 -0800 (PST) From: Andy Chiu To: linux-riscv@lists.infradead.org, palmer@dabbelt.com, anup@brainfault.org, atishp@atishpatra.org, kvm-riscv@lists.infradead.org, kvm@vger.kernel.org Cc: vineetg@rivosinc.com, greentime.hu@sifive.com, guoren@linux.alibaba.com, Andy Chiu , Paul Walmsley , Albert Ou , Heiko Stuebner , Andrew Jones , Lad Prabhakar , Conor Dooley , Jisheng Zhang , Vincent Chen , Guo Ren , Li Zhengyu , Masahiro Yamada , Changbin Du , Richard Henderson Subject: [PATCH -next v13 10/19] riscv: Allocate user's vector context in the first-use trap Date: Wed, 25 Jan 2023 14:20:47 +0000 Message-Id: <20230125142056.18356-11-andy.chiu@sifive.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230125142056.18356-1-andy.chiu@sifive.com> References: <20230125142056.18356-1-andy.chiu@sifive.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230125_062208_873395_1D49F40E X-CRM114-Status: GOOD ( 21.13 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Vector unit is disabled by default for all user processes. Thus, a process will take a trap (illegal instruction) into kernel at the first time when it uses Vector. Only after then, the kernel allocates V context and starts take care of the context for that user process. Suggested-by: Richard Henderson Link: https://lore.kernel.org/r/3923eeee-e4dc-0911-40bf-84c34aee962d@linaro.org Signed-off-by: Andy Chiu --- arch/riscv/include/asm/insn.h | 24 +++++++++ arch/riscv/include/asm/vector.h | 2 + arch/riscv/kernel/Makefile | 1 + arch/riscv/kernel/vector.c | 89 +++++++++++++++++++++++++++++++++ 4 files changed, 116 insertions(+) create mode 100644 arch/riscv/kernel/vector.c diff --git a/arch/riscv/include/asm/insn.h b/arch/riscv/include/asm/insn.h index 25ef9c0b19e7..b1ef3617881f 100644 --- a/arch/riscv/include/asm/insn.h +++ b/arch/riscv/include/asm/insn.h @@ -133,6 +133,24 @@ #define RVG_OPCODE_JALR 0x67 #define RVG_OPCODE_JAL 0x6f #define RVG_OPCODE_SYSTEM 0x73 +#define RVG_SYSTEM_CSR_OFF 20 +#define RVG_SYSTEM_CSR_MASK GENMASK(12, 0) + +/* parts of opcode for RVV */ +#define OPCODE_VECTOR 0x57 +#define LSFP_WIDTH_RVV_8 0 +#define LSFP_WIDTH_RVV_16 5 +#define LSFP_WIDTH_RVV_32 6 +#define LSFP_WIDTH_RVV_64 7 + +/* parts of opcode for RVF, RVD and RVQ */ +#define LSFP_WIDTH_OFF 12 +#define LSFP_WIDTH_MASK GENMASK(3, 0) +#define LSFP_WIDTH_FP_W 2 +#define LSFP_WIDTH_FP_D 3 +#define LSFP_WIDTH_FP_Q 4 +#define OPCODE_LOADFP 0x07 +#define OPCODE_STOREFP 0x27 /* parts of opcode for RVC*/ #define RVC_OPCODE_C0 0x0 @@ -291,6 +309,12 @@ static __always_inline bool riscv_insn_is_branch(u32 code) (RVC_X(x_, RVC_B_IMM_7_6_OPOFF, RVC_B_IMM_7_6_MASK) << RVC_B_IMM_7_6_OFF) | \ (RVC_IMM_SIGN(x_) << RVC_B_IMM_SIGN_OFF); }) +#define EXTRACT_LOAD_STORE_FP_WIDTH(x) \ + ({typeof(x) x_ = (x); RV_X(x_, LSFP_WIDTH_OFF, LSFP_WIDTH_MASK); }) + +#define EXTRACT_SYSTEM_CSR(x) \ + ({typeof(x) x_ = (x); RV_X(x_, RVG_SYSTEM_CSR_OFF, RVG_SYSTEM_CSR_MASK); }) + /* * Get the immediate from a J-type instruction. * diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h index f8a9e37c4374..7c77696d704a 100644 --- a/arch/riscv/include/asm/vector.h +++ b/arch/riscv/include/asm/vector.h @@ -19,6 +19,7 @@ #define CSR_STR(x) __ASM_STR(x) extern unsigned long riscv_vsize; +bool rvv_first_use_handler(struct pt_regs *regs); static __always_inline bool has_vector(void) { @@ -138,6 +139,7 @@ static inline void vstate_restore(struct task_struct *task, struct pt_regs; static __always_inline bool has_vector(void) { return false; } +static inline bool rvv_first_use_handler(struct pt_regs *regs) { return false; } static inline bool vstate_query(struct pt_regs *regs) { return false; } #define riscv_vsize (0) #define vstate_save(task, regs) do {} while (0) diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index 4cf303a779ab..48d345a5f326 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -55,6 +55,7 @@ obj-$(CONFIG_MMU) += vdso.o vdso/ obj-$(CONFIG_RISCV_M_MODE) += traps_misaligned.o obj-$(CONFIG_FPU) += fpu.o +obj-$(CONFIG_RISCV_ISA_V) += vector.o obj-$(CONFIG_SMP) += smpboot.o obj-$(CONFIG_SMP) += smp.o obj-$(CONFIG_SMP) += cpu_ops.o diff --git a/arch/riscv/kernel/vector.c b/arch/riscv/kernel/vector.c new file mode 100644 index 000000000000..cdd58d1c8b3c --- /dev/null +++ b/arch/riscv/kernel/vector.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2023 SiFive + * Author: Andy Chiu + */ +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +static bool insn_is_vector(u32 insn_buf) +{ + u32 opcode = insn_buf & __INSN_OPCODE_MASK; + /* + * All V-related instructions, including CSR operations are 4-Byte. So, + * do not handle if the instruction length is not 4-Byte. + */ + if (unlikely(GET_INSN_LENGTH(insn_buf) != 4)) + return false; + if (opcode == OPCODE_VECTOR) { + return true; + } else if (opcode == OPCODE_LOADFP || opcode == OPCODE_STOREFP) { + u32 width = EXTRACT_LOAD_STORE_FP_WIDTH(insn_buf); + + if (width == LSFP_WIDTH_RVV_8 || width == LSFP_WIDTH_RVV_16 || + width == LSFP_WIDTH_RVV_32 || width == LSFP_WIDTH_RVV_64) + return true; + } else if (opcode == RVG_OPCODE_SYSTEM) { + u32 csr = EXTRACT_SYSTEM_CSR(insn_buf); + + if ((csr >= CSR_VSTART && csr <= CSR_VCSR) || + (csr >= CSR_VL && csr <= CSR_VLENB)) + return true; + } + return false; +} + +int rvv_thread_zalloc(void) +{ + void *datap; + + datap = kzalloc(riscv_vsize, GFP_KERNEL); + if (!datap) + return -ENOMEM; + current->thread.vstate.datap = datap; + memset(¤t->thread.vstate, 0, offsetof(struct __riscv_v_state, + datap)); + return 0; +} + +bool rvv_first_use_handler(struct pt_regs *regs) +{ + __user u32 *epc = (u32 *)regs->epc; + u32 tval = (u32)regs->badaddr; + + /* If V has been enabled then it is not the first-use trap */ + if (vstate_query(regs)) + return false; + /* Get the instruction */ + if (!tval) { + if (__get_user(tval, epc)) + return false; + } + /* Filter out non-V instructions */ + if (!insn_is_vector(tval)) + return false; + /* Sanity check. datap should be null by the time of the first-use trap */ + WARN_ON(current->thread.vstate.datap); + /* + * Now we sure that this is a V instruction. And it executes in the + * context where VS has been off. So, try to allocate the user's V + * context and resume execution. + */ + if (rvv_thread_zalloc()) { + force_sig(SIGKILL); + return true; + } + vstate_on(regs); + return true; +} + -- 2.17.1 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv