From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5240D3BD64E; Fri, 10 Apr 2026 12:19:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775823551; cv=none; b=Coyxp6lIkeIFJNsrdxqQn9VNq1Dd91+mjgGIwEmVZY/vhJHaaQbLzss0itQikN3TCbMosxkZXTrvQJDjv1kZVV8z6oANp3jyIoFNlrlLPx0te64vF1RKRbLA+XZnsx/tRlFE/uTmVw6Al17j/P/m8zcSltP3BO4BwifqbBek078= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775823551; c=relaxed/simple; bh=bea3byi4f+lJwA9RE9L4RIIWG0LfPmc09XAUdHtlAlE=; h=Date:Message-ID:From:To:Subject:References:MIME-Version: Content-Type:cc; b=uGpT1AiSAr6h9n0GuuSfkG3onoJpNqNwUxMKeAdYGd/A7E5CeZ+0ov7ASXousy/aPcBeiA5onN4l/Jg/p8ouE1RM207z0wtwddA/X49s6JYNzeocBB0FD3If/ow0mRlbh9MpiRgNglAjIoOOZSQiiqgMGSXtrdSw5p1WuNB/hWg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YwhpP/sf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="YwhpP/sf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 455B0C2BC87; Fri, 10 Apr 2026 12:19:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775823550; bh=bea3byi4f+lJwA9RE9L4RIIWG0LfPmc09XAUdHtlAlE=; h=Date:From:To:Subject:References:cc:From; b=YwhpP/sfl2uNAokHMGyDzPyXqsYG5Z3HHapkhzwVASiSkGSv1ImeSFBY018VYZGU6 EPRk8H/tD4bE94DCGFfik82fydH/mvkzeKH2zcGHFzmiPQlK2yTJNXmBvp6CR6/aKP ZUXJ1ridIfNl+octSklnUsCiAFVq0bMAbDZHArZ2XlGiEpILEnKNdARJlXe1YoLGU7 gTGiAjrmuKfAH7Stm5YSWpKnJ3J0WABG0fiD/+Dm/7aJCfY6aDBkC0dcXhqkELemEA OLCKD9b/UmnIij2UMaT5laELpK9/RUq1POEHXDOcdk6mujQiavRoj/L2U3OHpVV16q LiEll066ex31A== Date: Fri, 10 Apr 2026 14:19:08 +0200 Message-ID: <20260410120318.121043259@kernel.org> User-Agent: quilt/0.68 From: Thomas Gleixner To: LKML Subject: [patch 08/38] x86/tsc: Use rdtsc() instead of get_cycles() References: <20260410120044.031381086@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 cc: Arnd Bergmann , x86@kernel.org, Lu Baolu , iommu@lists.linux.dev, Michael Grzeschik , netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Herbert Xu , linux-crypto@vger.kernel.org, Vlastimil Babka , linux-mm@kvack.org, David Woodhouse , Bernie Thompson , linux-fbdev@vger.kernel.org, "Theodore Tso" , linux-ext4@vger.kernel.org, Andrew Morton , Uladzislau Rezki , Marco Elver , Dmitry Vyukov , kasan-dev@googlegroups.com, Andrey Ryabinin , Thomas Sailer , linux-hams@vger.kernel.org, "Jason A. Donenfeld" , Richard Henderson , linux-alpha@vger.kernel.org, Russell King , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Huacai Chen , loongarch@lists.linux.dev, Geert Uytterhoeven , linux-m68k@lists.linux-m68k.org, Dinh Nguyen , Jonas Bonn , linux-openrisc@vger.kernel.org, Helge Deller , linux-parisc@vger.kernel.org, Michael Ellerman , linuxppc-dev@lists.ozlabs.org, Paul Walmsley , linux-riscv@lists.infradead.org, Heiko Carstens , linux-s390@vger.kernel.org, "David S. Miller" , sparclinux@vger.kernel.org This code knows that TSC is available so there is no point to use the TSC feature guarded get_cycles(). No functional change. Signed-off-by: Thomas Gleixner --- arch/x86/kernel/tsc.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -371,12 +371,12 @@ static u64 tsc_read_refs(u64 *p, int hpe int i; for (i = 0; i < MAX_RETRIES; i++) { - t1 = get_cycles(); + t1 = rdtsc(); if (hpet) *p = hpet_readl(HPET_COUNTER) & 0xFFFFFFFF; else *p = acpi_pm_read_early(); - t2 = get_cycles(); + t2 = rdtsc(); if ((t2 - t1) < thresh) return t2; } @@ -468,13 +468,13 @@ static unsigned long pit_calibrate_tsc(u outb(latch & 0xff, 0x42); outb(latch >> 8, 0x42); - tsc = t1 = t2 = get_cycles(); + tsc = t1 = t2 = rdtsc(); pitcnt = 0; tscmax = 0; tscmin = ULONG_MAX; while ((inb(0x61) & 0x20) == 0) { - t2 = get_cycles(); + t2 = rdtsc(); delta = t2 - tsc; tsc = t2; if ((unsigned long) delta < tscmin) @@ -553,9 +553,9 @@ static inline int pit_expect_msb(unsigne if (!pit_verify_msb(val)) break; prev_tsc = tsc; - tsc = get_cycles(); + tsc = rdtsc(); } - *deltap = get_cycles() - prev_tsc; + *deltap = rdtsc() - prev_tsc; *tscp = tsc; /*