From patchwork Mon Oct 7 02:56:49 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: LIU Zhiwei X-Patchwork-Id: 13823972 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 F3B29CFB424 for ; Mon, 7 Oct 2024 02:58:15 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sxdwP-0002L6-Pv; Sun, 06 Oct 2024 22:57:45 -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 1sxdwN-0002KE-H8; Sun, 06 Oct 2024 22:57:43 -0400 Received: from out30-111.freemail.mail.aliyun.com ([115.124.30.111]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sxdwL-0002iJ-76; Sun, 06 Oct 2024 22:57:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1728269856; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=WHGwy8Pl676c3JyI1NdVn3WOp+5BPrLFfgXsuSoDjyg=; b=ByndipgDdMXvOFVf956+nuAvnJJ/zLTIoFwsDFbBQVFLksiFXreOlO0MQkkenClZbfjJc21tD0N7W2p1HynupcT1ix+531IdOKWfUqxL/IIXW5kJJhLkEK51u3FIPdpP4l6sJqhP7UySOKGUp+1mzEo2NnvQ7u2qIG7DqOYBFhg= Received: from localhost.localdomain(mailfrom:zhiwei_liu@linux.alibaba.com fp:SMTPD_---0WGLM8rW_1728269854) by smtp.aliyun-inc.com; Mon, 07 Oct 2024 10:57:35 +0800 From: LIU Zhiwei To: qemu-devel@nongnu.org Cc: qemu-riscv@nongnu.org, palmer@dabbelt.com, alistair.francis@wdc.com, dbarboza@ventanamicro.com, liwei1518@gmail.com, bmeng.cn@gmail.com, richard.henderson@linaro.org, TANG Tiancheng , Liu Zhiwei Subject: [PATCH v5 01/12] util: Add RISC-V vector extension probe in cpuinfo Date: Mon, 7 Oct 2024 10:56:49 +0800 Message-Id: <20241007025700.47259-2-zhiwei_liu@linux.alibaba.com> X-Mailer: git-send-email 2.39.3 (Apple Git-146) In-Reply-To: <20241007025700.47259-1-zhiwei_liu@linux.alibaba.com> References: <20241007025700.47259-1-zhiwei_liu@linux.alibaba.com> MIME-Version: 1.0 Received-SPF: pass client-ip=115.124.30.111; envelope-from=zhiwei_liu@linux.alibaba.com; helo=out30-111.freemail.mail.aliyun.com X-Spam_score_int: -174 X-Spam_score: -17.5 X-Spam_bar: ----------------- X-Spam_report: (-17.5 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, ENV_AND_HDR_SPF_MATCH=-0.5, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, UNPARSEABLE_RELAY=0.001, USER_IN_DEF_DKIM_WL=-7.5, USER_IN_DEF_SPF_WL=-7.5 autolearn=ham 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 From: TANG Tiancheng Add support for probing RISC-V vector extension availability in the backend. This information will be used when deciding whether to use vector instructions in code generation. Cache lg2(vlenb) for the backend. The storing of lg2(vlenb) means we can convert all of the division into subtraction. While the compiler doesn't support RISCV_HWPROBE_EXT_ZVE64X, we use RISCV_HWPROBE_IMA_V instead. RISCV_HWPROBE_IMA_V is more strictly constrainted than RISCV_HWPROBE_EXT_ZVE64X. At least in current QEMU implemenation, the V vector extension depends on the zve64d extension. Signed-off-by: TANG Tiancheng Reviewed-by: Liu Zhiwei --- host/include/riscv/host/cpuinfo.h | 2 ++ util/cpuinfo-riscv.c | 24 ++++++++++++++++++++++-- 2 files changed, 24 insertions(+), 2 deletions(-) diff --git a/host/include/riscv/host/cpuinfo.h b/host/include/riscv/host/cpuinfo.h index 2b00660e36..cdc784e7b6 100644 --- a/host/include/riscv/host/cpuinfo.h +++ b/host/include/riscv/host/cpuinfo.h @@ -10,9 +10,11 @@ #define CPUINFO_ZBA (1u << 1) #define CPUINFO_ZBB (1u << 2) #define CPUINFO_ZICOND (1u << 3) +#define CPUINFO_ZVE64X (1u << 4) /* Initialized with a constructor. */ extern unsigned cpuinfo; +extern unsigned riscv_lg2_vlenb; /* * We cannot rely on constructor ordering, so other constructors must diff --git a/util/cpuinfo-riscv.c b/util/cpuinfo-riscv.c index 497ce12680..bab782745b 100644 --- a/util/cpuinfo-riscv.c +++ b/util/cpuinfo-riscv.c @@ -4,6 +4,7 @@ */ #include "qemu/osdep.h" +#include "qemu/host-utils.h" #include "host/cpuinfo.h" #ifdef CONFIG_ASM_HWPROBE_H @@ -12,6 +13,7 @@ #endif unsigned cpuinfo; +unsigned riscv_lg2_vlenb; static volatile sig_atomic_t got_sigill; static void sigill_handler(int signo, siginfo_t *si, void *data) @@ -33,7 +35,7 @@ static void sigill_handler(int signo, siginfo_t *si, void *data) /* Called both as constructor and (possibly) via other constructors. */ unsigned __attribute__((constructor)) cpuinfo_init(void) { - unsigned left = CPUINFO_ZBA | CPUINFO_ZBB | CPUINFO_ZICOND; + unsigned left = CPUINFO_ZBA | CPUINFO_ZBB | CPUINFO_ZICOND | CPUINFO_ZVE64X; unsigned info = cpuinfo; if (info) { @@ -49,6 +51,9 @@ unsigned __attribute__((constructor)) cpuinfo_init(void) #endif #if defined(__riscv_arch_test) && defined(__riscv_zicond) info |= CPUINFO_ZICOND; +#endif +#if defined(__riscv_arch_test) && defined(__riscv_zve64x) + info |= CPUINFO_ZVE64X; #endif left &= ~info; @@ -64,7 +69,8 @@ unsigned __attribute__((constructor)) cpuinfo_init(void) && pair.key >= 0) { info |= pair.value & RISCV_HWPROBE_EXT_ZBA ? CPUINFO_ZBA : 0; info |= pair.value & RISCV_HWPROBE_EXT_ZBB ? CPUINFO_ZBB : 0; - left &= ~(CPUINFO_ZBA | CPUINFO_ZBB); + info |= pair.value & RISCV_HWPROBE_IMA_V ? CPUINFO_ZVE64X : 0; + left &= ~(CPUINFO_ZBA | CPUINFO_ZBB | CPUINFO_ZVE64X); #ifdef RISCV_HWPROBE_EXT_ZICOND info |= pair.value & RISCV_HWPROBE_EXT_ZICOND ? CPUINFO_ZICOND : 0; left &= ~CPUINFO_ZICOND; @@ -112,6 +118,20 @@ unsigned __attribute__((constructor)) cpuinfo_init(void) assert(left == 0); } + if (info & CPUINFO_ZVE64X) { + /* + * We are guaranteed by RVV-1.0 that VLEN is a power of 2. + * We are guaranteed by Zve64x that VLEN >= 64, and that + * EEW of {8,16,32,64} are supported. + * + * Cache VLEN in a convenient form. + */ + unsigned long vlenb; + /* Read csr "vlenb" with "csrr %0, vlenb" : "=r"(vlenb) */ + asm volatile(".insn i 0x73, 0x2, %0, zero, -990" : "=r"(vlenb)); + riscv_lg2_vlenb = ctz32(vlenb); + } + info |= CPUINFO_ALWAYS; cpuinfo = info; return info;