From patchwork Thu Jul 25 23:45:51 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Deepak Gupta X-Patchwork-Id: 13742218 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 93833C3DA70 for ; Thu, 25 Jul 2024 23:47:34 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sX8AN-0008Kc-5h; Thu, 25 Jul 2024 19:46:35 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sX8AI-00085F-7s for qemu-devel@nongnu.org; Thu, 25 Jul 2024 19:46:30 -0400 Received: from mail-oi1-x231.google.com ([2607:f8b0:4864:20::231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1sX8AF-0005Ir-PU for qemu-devel@nongnu.org; Thu, 25 Jul 2024 19:46:29 -0400 Received: by mail-oi1-x231.google.com with SMTP id 5614622812f47-3db157d3bb9so239418b6e.2 for ; Thu, 25 Jul 2024 16:46:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1721951186; x=1722555986; darn=nongnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=WXmmy9sQ6FdCwxmbQ1lXp5QB1YPROEJt1Bgbzc7d8Dg=; b=LZONunHW+RZGkjLLWk+hamP4hLhSri3vWJW98qnTPJrm88HilnG9909Y7nz/4WnQZr a1GgBryWRtpjIUwptoKtSv8mr4zUdbXyidEJtx+32vjP1zBghhQ2vGyqq3G6outJ7//E gHYMIjhXuBq55DRYH0hth1MJBNtGrVQ71JPsEOyWoyptTFFZHLIoGd6xwFKMgxdeQYvA 4BGrzBPvEPnZqloX/XitZLO/dQ3pJvx56UHCqGrbAqxORa9CdtZlCeZ+ywuZruPUYpDK CKyd+T3OzuuebJJEnGyNt8YL6hQHc+7UvUmBiUznEpyWBTAS3zveZkd/hOH0bTrmB+fz h+/g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721951186; x=1722555986; h=content-transfer-encoding:mime-version: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=WXmmy9sQ6FdCwxmbQ1lXp5QB1YPROEJt1Bgbzc7d8Dg=; b=R4OI0iuTQUu4fzWElKjtJ+do9W4SWTfspNRXgBRdCbrIDsufj0pGI/QOxLee2dNqPV 3JfOoK7sbJMYXu4p/eSve7J1Q2gPQR+raRE1IXKbENIdeyMnIx8Z5j+4S02pM6D+S/z6 xXGRNiBcae44/WhJ6lu0rOV1DzbF+B90qkbIhP2CGm/GsvZVBnfYFiSdYfM3KQffMRjU zZEG8ofqQQWA3HqEBc5SqzYM20mprotZt5kIS2wT1rSUW1r0UfiBFgMYfhnSsOT81gaR MgY2JwfaSN35UV77EO/Bni0LvHGQbQSrscCn/Dhzb3WEgbM7+zFshKBgZ3C5fwZ+TByk fPbQ== X-Forwarded-Encrypted: i=1; AJvYcCVtaBJ/KhkR5bZ7uClmBHMEtTsDG5R93PqFXbp7ht0SDqDyXlnB4g5y4YVovU3LVwSPobMjQldrfTKJ1aLDuuKxkPzpzdI= X-Gm-Message-State: AOJu0YyZXA7g3e5aCTy+dto2ilOlxob7lkj6qpgkbivydLgmz3kJdLQi qePnwQd1keai5D7prw2YpDanxnoyRgbtqE3SU5ShXWBh2OER0SXutKwzA1KYCCk= X-Google-Smtp-Source: AGHT+IHTcTV049RgkkheDTV4ydvBUYxsIoXRmfn7ShZIbpMd59GBBzcSEwkAxSaqQT5nyf2pidtgzw== X-Received: by 2002:a05:6808:e8e:b0:3d9:dd93:9902 with SMTP id 5614622812f47-3db140e7badmr3649863b6e.14.1721951186239; Thu, 25 Jul 2024 16:46:26 -0700 (PDT) Received: from debug.ba.rivosinc.com ([64.71.180.162]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-70ead8128d0sm1647565b3a.118.2024.07.25.16.46.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 25 Jul 2024 16:46:25 -0700 (PDT) From: Deepak Gupta To: qemu-riscv@nongnu.org, qemu-devel@nongnu.org, jim.shu@sifive.com, andy.chiu@sifive.com, jesse.huang@sifive.com, kito.cheng@sifive.com Cc: palmer@dabbelt.com, Alistair.Francis@wdc.com, laurent@vivier.eu, bmeng.cn@gmail.com, liwei1518@gmail.com, dbarboza@ventanamicro.com, zhiwei_liu@linux.alibaba.com, Deepak Gupta Subject: [PATCH 02/24] target/riscv: Introduce elp state and enabling controls for zicfilp Date: Thu, 25 Jul 2024 16:45:51 -0700 Message-ID: <20240725234614.3850142-3-debug@rivosinc.com> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240725234614.3850142-1-debug@rivosinc.com> References: <20240725234614.3850142-1-debug@rivosinc.com> MIME-Version: 1.0 Received-SPF: pass client-ip=2607:f8b0:4864:20::231; envelope-from=debug@rivosinc.com; helo=mail-oi1-x231.google.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org zicfilp introduces a new state elp ("expected landing pad") in cpu. During normal execution, elp is idle (NO_LP_EXPECTED) i.e not expecting landing pad. On an indirect call, elp moves LP_EXPECTED. When elp is LP_EXPECTED, only a subsquent landing pad instruction can set state back to NO_LP_EXPECTED. On reset, elp is set to NO_LP_EXPECTED. zicfilp is enabled via bit2 in *envcfg CSRs. Enabling control for M-mode is in mseccfg CSR at bit position 10. On trap, elp state is saved away in *status. Signed-off-by: Deepak Gupta Co-developed-by: Jim Shu Co-developed-by: Andy Chiu --- target/riscv/cpu.c | 3 +++ target/riscv/cpu.h | 2 ++ target/riscv/cpu_bits.h | 12 ++++++++++++ target/riscv/csr.c | 31 +++++++++++++++++++++++++++++++ target/riscv/pmp.c | 5 +++++ target/riscv/pmp.h | 3 ++- 6 files changed, 55 insertions(+), 1 deletion(-) diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c index 5dfb3f39ab..82fa85a8d6 100644 --- a/target/riscv/cpu.c +++ b/target/riscv/cpu.c @@ -994,6 +994,9 @@ static void riscv_cpu_reset_hold(Object *obj, ResetType type) /* mmte is supposed to have pm.current hardwired to 1 */ env->mmte |= (EXT_STATUS_INITIAL | MMTE_M_PM_CURRENT); + /* on reset elp is set to NO_LP_EXPECTED */ + env->elp = NO_LP_EXPECTED; + /* * Bits 10, 6, 2 and 12 of mideleg are read only 1 when the Hypervisor * extension is enabled. diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h index 87742047ce..ae436a3179 100644 --- a/target/riscv/cpu.h +++ b/target/riscv/cpu.h @@ -222,6 +222,8 @@ struct CPUArchState { target_ulong jvt; + /* elp state for zicfilp extension */ + cfi_elp elp; #ifdef CONFIG_USER_ONLY uint32_t elf_flags; #endif diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h index c257c5ed7d..127f2179dc 100644 --- a/target/riscv/cpu_bits.h +++ b/target/riscv/cpu_bits.h @@ -545,6 +545,8 @@ #define MSTATUS_TVM 0x00100000 /* since: priv-1.10 */ #define MSTATUS_TW 0x00200000 /* since: priv-1.10 */ #define MSTATUS_TSR 0x00400000 /* since: priv-1.10 */ +#define MSTATUS_SPELP 0x00800000 /* zicfilp */ +#define MSTATUS_MPELP 0x020000000000 /* zicfilp */ #define MSTATUS_GVA 0x4000000000ULL #define MSTATUS_MPV 0x8000000000ULL @@ -575,12 +577,19 @@ typedef enum { #define SSTATUS_XS 0x00018000 #define SSTATUS_SUM 0x00040000 /* since: priv-1.10 */ #define SSTATUS_MXR 0x00080000 +#define SSTATUS_SPELP MSTATUS_SPELP /* zicfilp */ #define SSTATUS64_UXL 0x0000000300000000ULL #define SSTATUS32_SD 0x80000000 #define SSTATUS64_SD 0x8000000000000000ULL +/* enum for branch tracking state in cpu/hart */ +typedef enum { + NO_LP_EXPECTED = 0, + LP_EXPECTED = 1, +} cfi_elp; + /* hstatus CSR bits */ #define HSTATUS_VSBE 0x00000020 #define HSTATUS_GVA 0x00000040 @@ -747,6 +756,7 @@ typedef enum RISCVException { /* Execution environment configuration bits */ #define MENVCFG_FIOM BIT(0) +#define MENVCFG_LPE BIT(2) /* zicfilp */ #define MENVCFG_CBIE (3UL << 4) #define MENVCFG_CBCFE BIT(6) #define MENVCFG_CBZE BIT(7) @@ -760,11 +770,13 @@ typedef enum RISCVException { #define MENVCFGH_STCE BIT(31) #define SENVCFG_FIOM MENVCFG_FIOM +#define SENVCFG_LPE MENVCFG_LPE #define SENVCFG_CBIE MENVCFG_CBIE #define SENVCFG_CBCFE MENVCFG_CBCFE #define SENVCFG_CBZE MENVCFG_CBZE #define HENVCFG_FIOM MENVCFG_FIOM +#define HENVCFG_LPE MENVCFG_LPE #define HENVCFG_CBIE MENVCFG_CBIE #define HENVCFG_CBCFE MENVCFG_CBCFE #define HENVCFG_CBZE MENVCFG_CBZE diff --git a/target/riscv/csr.c b/target/riscv/csr.c index 432c59dc66..5771a14848 100644 --- a/target/riscv/csr.c +++ b/target/riscv/csr.c @@ -1400,6 +1400,11 @@ static RISCVException write_mstatus(CPURISCVState *env, int csrno, } } + /* If cfi lp extension is available, then apply cfi lp mask */ + if (env_archcpu(env)->cfg.ext_zicfilp) { + mask |= (MSTATUS_MPELP | MSTATUS_SPELP); + } + mstatus = (mstatus & ~mask) | (val & mask); env->mstatus = mstatus; @@ -2101,6 +2106,10 @@ static RISCVException write_menvcfg(CPURISCVState *env, int csrno, mask |= (cfg->ext_svpbmt ? MENVCFG_PBMTE : 0) | (cfg->ext_sstc ? MENVCFG_STCE : 0) | (cfg->ext_svadu ? MENVCFG_ADUE : 0); + + if (env_archcpu(env)->cfg.ext_zicfilp) { + mask |= MENVCFG_LPE; + } } env->menvcfg = (env->menvcfg & ~mask) | (val & mask); @@ -2153,6 +2162,10 @@ static RISCVException write_senvcfg(CPURISCVState *env, int csrno, return ret; } + if (env_archcpu(env)->cfg.ext_zicfilp) { + mask |= SENVCFG_LPE; + } + env->senvcfg = (env->senvcfg & ~mask) | (val & mask); return RISCV_EXCP_NONE; } @@ -2190,6 +2203,10 @@ static RISCVException write_henvcfg(CPURISCVState *env, int csrno, if (riscv_cpu_mxl(env) == MXL_RV64) { mask |= env->menvcfg & (HENVCFG_PBMTE | HENVCFG_STCE | HENVCFG_ADUE); + + if (env_archcpu(env)->cfg.ext_zicfilp) { + mask |= HENVCFG_LPE; + } } env->henvcfg = (env->henvcfg & ~mask) | (val & mask); @@ -2654,6 +2671,10 @@ static RISCVException read_sstatus_i128(CPURISCVState *env, int csrno, mask |= SSTATUS64_UXL; } + if (env_archcpu(env)->cfg.ext_zicfilp) { + mask |= SSTATUS_SPELP; + } + *val = int128_make128(sstatus, add_status_sd(MXL_RV128, sstatus)); return RISCV_EXCP_NONE; } @@ -2665,6 +2686,11 @@ static RISCVException read_sstatus(CPURISCVState *env, int csrno, if (env->xl != MXL_RV32 || env->debugger) { mask |= SSTATUS64_UXL; } + + if (env_archcpu(env)->cfg.ext_zicfilp) { + mask |= SSTATUS_SPELP; + } + /* TODO: Use SXL not MXL. */ *val = add_status_sd(riscv_cpu_mxl(env), env->mstatus & mask); return RISCV_EXCP_NONE; @@ -2680,6 +2706,11 @@ static RISCVException write_sstatus(CPURISCVState *env, int csrno, mask |= SSTATUS64_UXL; } } + + if (env_archcpu(env)->cfg.ext_zicfilp) { + mask |= SSTATUS_SPELP; + } + target_ulong newval = (env->mstatus & ~mask) | (val & mask); return write_mstatus(env, CSR_MSTATUS, newval); } diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c index 9eea397e72..1111d08d08 100644 --- a/target/riscv/pmp.c +++ b/target/riscv/pmp.c @@ -598,6 +598,11 @@ void mseccfg_csr_write(CPURISCVState *env, target_ulong val) val &= ~(MSECCFG_MMWP | MSECCFG_MML | MSECCFG_RLB); } + /* M-mode forward cfi to be enabled if cfi extension is implemented */ + if (env_archcpu(env)->cfg.ext_zicfilp) { + val |= (val & MSECCFG_MLPE); + } + env->mseccfg = val; } diff --git a/target/riscv/pmp.h b/target/riscv/pmp.h index f5c10ce85c..e0530a17a3 100644 --- a/target/riscv/pmp.h +++ b/target/riscv/pmp.h @@ -44,7 +44,8 @@ typedef enum { MSECCFG_MMWP = 1 << 1, MSECCFG_RLB = 1 << 2, MSECCFG_USEED = 1 << 8, - MSECCFG_SSEED = 1 << 9 + MSECCFG_SSEED = 1 << 9, + MSECCFG_MLPE = 1 << 10, } mseccfg_field_t; typedef struct {