From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 2414A4B4891 for ; Wed, 7 Oct 2026 14:59:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791385191; cv=none; b=jrVuVOIPCcU6WGMhiFKLO4j405P4jK7vcQmcZ/hx/GdU5gKgi3jYMj85OlJpAVLfhCgX7ftf1kQuy702uOPaYuOuRRHx/eUGyk5dueTDsJ76YtvEl/pkFCNT0AK1YWDER1uPQNOfaTd0tEGyi0Y7GpwCHnzwKoIjBzj/c8rftyw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791385191; c=relaxed/simple; bh=Z2Bdct4GuZTfHJrkKxcsnWcaneoEa+kNJUkdRNO7FVY=; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References: MIME-Version:Content-Type; b=vFByNf1VMeZR7ZDFHytSBOptDxwsg5nfob2ijVAFc7NZpTNfi9daJqWx/Ic1HfZBXIi7a7tXu/I9uWfbrb8T/PDuAwTkOtzas/JUmQdILrO5yOjSVrqSS8uHejJJ6oDJQlnNmmk2byzQOlE6Jwt2bFbuEAnjHqDQIw2iYyC1Izk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WgXBQx74; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WgXBQx74" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 57F431F000FF; Wed, 7 Oct 2026 14:59:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791385187; bh=RlbDPA6UwQ0YRs0y1zeJhCOYJioG5GQ5Xlbiv1h43G8=; h=Date:From:To:cc:Subject:In-Reply-To:References; b=WgXBQx74jpl0plYm2kVRYv5yN98oRwxzz/GBR1MpGMGhA/+pGKF2gzsF/PJXYo2+k bxDF8AeVQVrY9Zi5jIEemlWBCbU5plt9WrUauBfyZY3pxKu20+HGI24Pk6mXcC0TFp 1nbdpHQmOQRGaWLC4TTUO4hGGfBpqd+vNl0HFOoigPYDb3jTwYDyUPDuoQhqT1Z8C+ zUFgWdmL6V3/ACgFAvx0Y1d1HVD/aExB1qg/r4ltTG4ZvagywX63T+TKGOQMg+cBhU aiTnPeRJLKUf2tI7XXeJm9Eju2EbwgFgsFaoEA/86MzrXKKpmXVndsCa6bF0BHrUts DhwdDDhQG7EaQ== Date: Wed, 7 Oct 2026 08:59:41 -0600 (MDT) From: Paul Walmsley To: Aleksa Paunovic cc: Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , "Maciej W. Rozycki" , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Djordje Todorovic Subject: Re: [PATCH v3] riscv: Add ERRATA_MIPS_P8700_WFI to replace WFI with mips.pause In-Reply-To: <20260917-p8700-wfi-v3-1-ada4b0584712@htecgroup.com> Message-ID: References: <20260917-p8700-wfi-v3-1-ada4b0584712@htecgroup.com> 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=US-ASCII On Thu, 17 Sep 2026, Aleksa Paunovic via B4 Relay wrote: > From: Djordje Todorovic > > The MIPS P8700 has bugs with the WFI instruction. A WFI instruction > after a mispredicted branch can result in erroneous address > translation on the MIPS P8700. MIPS has not published an erratum > for this. > > The workaround uses the RISC-V alternatives framework to patch all WFI > instructions with the MIPS P8700 pause opcode (0x00501013) > at runtime when running on P8700 hardware. > > Two call sites are patched: > - arch/riscv/kernel/head.S: secondary hart parking loop > - arch/riscv/include/asm/processor.h: wait_for_interrupt() > > Signed-off-by: Djordje Todorovic > Signed-off-by: Aleksa Paunovic Thanks, queued for v7.4. - Paul