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 46D8DC53219 for ; Tue, 28 Jul 2026 02:19:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=vqunIx6I6P5BO4L84jXf9HBRjWQOIObJRsDL1K0ccjI=; b=WP2zOw5ONCyMwnLEpUAYeOJOvw LKe1holZXpcRhCCjhrTyeKFycQcgwi9f6peZhe6niG5Na9holUIKeiJwbolXnlo+rwJ0WEJOumJlk UG6XVKD0BO15lWhTyuwz7pybyIx7nx79Lor7J3COQROtOUUwcuAhoCp4IUS1LlUqbuhX1B+3ebBVj 2bWk5A5ymAIob7HR9ySzTDnlKeax4UBBvaA3HYt5rKplG4CbAOhAf86yhOQ/rjgfYqDeUalXhFcgh 6St4Lq7q2+fUwjJR2j4eCxvGK0FIDDLUS6ZmSqXtHFEmmWcLmSLu+34UcmdLosWlocpEpCNoap4Zd GeALQCAw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1woXPe-00000004Fhy-40xV; Tue, 28 Jul 2026 02:19:22 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1woXPb-00000004FeA-3VuJ for linux-um@lists.infradead.org; Tue, 28 Jul 2026 02:19:19 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 12D9E60A71; Tue, 28 Jul 2026 02:19:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 89EC01F00ACA; Tue, 28 Jul 2026 02:19:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785205158; bh=vqunIx6I6P5BO4L84jXf9HBRjWQOIObJRsDL1K0ccjI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=lf3Kb7s7ERyjF5IypfY0T9KLnfwe00i8m6zFnFXSc2YteyQ+ZWv1B503sLgxDqNRe Er+zJqLF15HSIAqm5CKZzMQaUw4x0SntnpffzWVoin+W7jxxbRy2Ewh75jnOWIbdzI TO1wFFuesF/XqTR7+XyDWhemQwfCwV9a/MCxKc3zzAw1zJWoDp65aooOlMhlfrSDPG VxvuX5nFVBhcBcyHLZ93jSpbQQX1Ncun4To56Q2jpz+9d1DyLdxVFgDvlDxODYnHY2 GIfnhjz18j1AYvkpQbyJbo65GiBCaQKV1naRbqFy8LTbsbOwvgnh968h+9Ws019VCW ln9b9V1LePxbw== From: Eric Biggers To: x86@kernel.org Cc: linux-um@lists.infradead.org, linux-raid@vger.kernel.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, Christoph Hellwig , Andrew Morton , Eric Biggers Subject: [PATCH v2 6/8] x86/fpu: Remove cpu_has_xfeatures() Date: Mon, 27 Jul 2026 19:16:01 -0700 Message-ID: <20260728021603.79870-7-ebiggers@kernel.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260728021603.79870-1-ebiggers@kernel.org> References: <20260728021603.79870-1-ebiggers@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org The only remaining caller of cpu_has_xfeatures() is print_xstate_features(), which uses it only to check and get the name of a single feature. Remove it and just inline the needed code into print_xstate_features(). This also makes the "unknown xstate feature" entry at index XFEATURE_MAX of xfeature_names[] unnecessary, so remove that too. Signed-off-by: Eric Biggers --- arch/x86/include/asm/fpu/api.h | 9 ------- arch/x86/kernel/fpu/xstate.c | 44 +++------------------------------- 2 files changed, 3 insertions(+), 50 deletions(-) diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h index 90c63fe19c0fb..cfed8b24d64f0 100644 --- a/arch/x86/include/asm/fpu/api.h +++ b/arch/x86/include/asm/fpu/api.h @@ -99,15 +99,6 @@ static inline void fpregs_assert_state_consistent(void) { } */ extern void switch_fpu_return(void); -/* - * Query the presence of one or more xfeatures. Works on any legacy CPU as well. - * - * If 'feature_name' is set then put a human-readable description of - * the feature there as well - this can be used to print error (or success) - * messages. - */ -extern int cpu_has_xfeatures(u64 xfeatures_mask, const char **feature_name); - /* Trap handling */ extern int fpu__exception_code(struct fpu *fpu, int trap_nr); extern void fpu_sync_fpstate(struct fpu *fpu); diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 904ff933c0d88..3c185b2828c71 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -66,8 +66,8 @@ static const char *xfeature_names[] = "AMX Tile config", "AMX Tile data", "APX registers", - "unknown xstate feature", }; +static_assert(ARRAY_SIZE(xfeature_names) == XFEATURE_MAX); static unsigned short xsave_cpuid_features[] __initdata = { [XFEATURE_FP] = X86_FEATURE_FPU, @@ -122,44 +122,6 @@ static inline unsigned int next_xfeature_order(unsigned int i, u64 mask) #define XSTATE_FLAG_SUPERVISOR BIT(0) #define XSTATE_FLAG_ALIGNED64 BIT(1) -/* - * Return whether the system supports a given xfeature. - * - * Also return the name of the (most advanced) feature that the caller requested: - */ -int cpu_has_xfeatures(u64 xfeatures_needed, const char **feature_name) -{ - u64 xfeatures_missing = xfeatures_needed & ~fpu_kernel_cfg.max_features; - - if (unlikely(feature_name)) { - long xfeature_idx, max_idx; - u64 xfeatures_print; - /* - * So we use FLS here to be able to print the most advanced - * feature that was requested but is missing. So if a driver - * asks about "XFEATURE_MASK_SSE | XFEATURE_MASK_YMM" we'll print the - * missing AVX feature - this is the most informative message - * to users: - */ - if (xfeatures_missing) - xfeatures_print = xfeatures_missing; - else - xfeatures_print = xfeatures_needed; - - xfeature_idx = fls64(xfeatures_print)-1; - max_idx = ARRAY_SIZE(xfeature_names)-1; - xfeature_idx = min(xfeature_idx, max_idx); - - *feature_name = xfeature_names[xfeature_idx]; - } - - if (xfeatures_missing) - return 0; - - return 1; -} -EXPORT_SYMBOL_GPL(cpu_has_xfeatures); - static bool xfeature_is_aligned64(int xfeature_nr) { return xstate_flags[xfeature_nr] & XSTATE_FLAG_ALIGNED64; @@ -302,9 +264,9 @@ static void __init print_xstate_features(void) for (i = 0; i < XFEATURE_MAX; i++) { u64 mask = BIT_ULL(i); - const char *name; + const char *name = xfeature_names[i]; - if (cpu_has_xfeatures(mask, &name)) + if (fpu_kernel_cfg.max_features & mask) pr_info("x86/fpu: Supporting XSAVE feature 0x%03Lx: '%s'\n", mask, name); } } -- 2.55.0