From patchwork Wed Oct 16 19:31:29 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Henderson X-Patchwork-Id: 13838812 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 73025D2A549 for ; Wed, 16 Oct 2024 19:36:00 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1t19kN-0002ft-22; Wed, 16 Oct 2024 15:31:51 -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 1t19kK-0002dZ-BF for qemu-devel@nongnu.org; Wed, 16 Oct 2024 15:31:48 -0400 Received: from mail-pl1-x62f.google.com ([2607:f8b0:4864:20::62f]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1t19kG-0003nf-NE for qemu-devel@nongnu.org; Wed, 16 Oct 2024 15:31:47 -0400 Received: by mail-pl1-x62f.google.com with SMTP id d9443c01a7336-20bb39d97d1so1543885ad.2 for ; Wed, 16 Oct 2024 12:31:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1729107103; x=1729711903; 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=k9pm4mmiOJ3ePRNfWoDr3osUdbmj8mTSaBfTsfRhvEA=; b=H2mYNCwIjh2gWxzIwji23kcmFroPqhHUIbXVhEcdmYjmKHeEZKpXEPcXt3qSM50dUl VyPd5OefxqqwzesB0vOZOOrnqM4r37bqgu2rfqgwVXWNG3OT5vmy63bQ1KtkPoMFiTMJ zPODQEKln1nfN2OeLyUw+MZAF17ryT+KlD8R3QFH5JwheSeQepUuXwPU4w8q6gHkfKyR lb+d0tvy2LG6GnbmVl5GlMtYapRrnkD0y01NGsmqHALicH2Rw4Bb3Wlv+PHpIbw5y5pI sbZ+G6OTIGYeERAKqMfnKVGc0w9Z5vT7WDaFvwdr+TzJlQIwhdBg1M9qvqQMYFaWRZh5 Trtw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1729107103; x=1729711903; 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=k9pm4mmiOJ3ePRNfWoDr3osUdbmj8mTSaBfTsfRhvEA=; b=gs2UhkyX8glUAddOCYx9ddN7JvLwfOdWzVbLaTvalNPFQ2UMZEraMpu3OVXp5st1wi iEjJ9GozbbjwPwbI3hEZdsnuKykGvv60hwwPbXF3EZJS6s1FZ77RvRMxVr8bX2gf+UTy 9CL0CtTW22FYq+7Af+/4PZ7Hqe2LH6LxdUXyiG4fUArIhwhEqDGFG0n8bpWgImhojTow ldwDADKFmum4fqSctFTwPaGhjsgWSD9uX/Rul3ilLI6QOHk7TkmzXLi1zdyGBDNl9CT4 fVPf5qFhpbA/dWV9fGYGNUq0H8fw7CIm2tgAQIJvU7ChPA9OkNra0hEWDpvKcEb4+vcm A73g== X-Gm-Message-State: AOJu0Yy1k5hUPXxCyQ9+juwBPRQ1md4Z+Ih3LXh2uIrotbmuAH3PGjVb Qqa9l3VN2+33ytLC2nHULjZJe2Zp5cTfy55ewE5Rtw7gCz1Y6X5J1STPgiMv7ckoB53rAmWWEIE S X-Google-Smtp-Source: AGHT+IEbxcJArg42k++Rr7k+42e+j+oxbTriW9eALQDzvP4g5pI/++j0U7VbgwUs5VFYQIIE3bYwWg== X-Received: by 2002:a17:903:2309:b0:20b:8907:b597 with SMTP id d9443c01a7336-20ca1682ab9mr258903615ad.28.1729107103360; Wed, 16 Oct 2024 12:31:43 -0700 (PDT) Received: from stoup.. (174-21-81-121.tukw.qwest.net. [174.21.81.121]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-20d1804b6b1sm32323945ad.189.2024.10.16.12.31.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Oct 2024 12:31:43 -0700 (PDT) From: Richard Henderson To: qemu-devel@nongnu.org Cc: qemu-riscv@nongnu.org, alistair.francis@wdc.com, zhiwei_liu@linux.alibaba.com, TANG Tiancheng Subject: [PATCH v6 03/14] util: Add RISC-V vector extension probe in cpuinfo Date: Wed, 16 Oct 2024 12:31:29 -0700 Message-ID: <20241016193140.2206352-4-richard.henderson@linaro.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20241016193140.2206352-1-richard.henderson@linaro.org> References: <20241016193140.2206352-1-richard.henderson@linaro.org> MIME-Version: 1.0 Received-SPF: pass client-ip=2607:f8b0:4864:20::62f; envelope-from=richard.henderson@linaro.org; helo=mail-pl1-x62f.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-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 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 Message-ID: <20241007025700.47259-2-zhiwei_liu@linux.alibaba.com> Signed-off-by: Richard Henderson --- 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 8cacc67645..16114ffd32 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 @@ -13,6 +14,7 @@ #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) @@ -34,7 +36,7 @@ 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) { @@ -50,6 +52,9 @@ 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; @@ -65,7 +70,8 @@ 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; @@ -113,6 +119,20 @@ 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;