From nobody Thu Sep 24 18:40:32 2026 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 351B429B78F; Tue, 22 Sep 2026 01:17:57 +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=1790039878; cv=none; b=bk++XYXCGtJbH3TsY1JuCpb8sMXWYGjHuHiwWMhWK/0+7UppnwvnLG8QeIQvM74PqrWgNpeb+ui+eo8Qud/03U9MPaV1i0XpMotIqZpaxPC2Dirg5BQF0M8AwykLqkC7koYRy75PBJwguNkSFgf+8oWF1Bj9eN9lpsmNY1AWAQs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790039878; c=relaxed/simple; bh=ZHVb45XCWO9w58LLzRNKyyIHjXI2eN1KtCPkmd2PO/g=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=RItw+6m0bVaCHXgV4QNDEPFFwqccJMChzEdBSV3D0l5z34GCFKd8al475wfhgAJjNp4tlgV2GalRmmAdy2H4ecY5F2mz9SSMShVvSgKcantEBrVBzGyFAavhNSEOw8MNGTuGE5qC6N1y0ttnEUuVmfdArYg0you+0+hkuKMs/8Y= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=c11bYG53; 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="c11bYG53" Received: by smtp.kernel.org (Postfix) with ESMTPS id B9E82C2BCB3; Tue, 22 Sep 2026 01:17:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1790039877; bh=ZHVb45XCWO9w58LLzRNKyyIHjXI2eN1KtCPkmd2PO/g=; h=From:Date:Subject:To:Cc:Reply-To:From; b=c11bYG53PqIeUNnE+PqljmY33Dxj4ecdevKrpwpUJnHv7q0jJzEPWwIkEvQId7ceC lKjxiXu49lJ3gby9d+hoGuVqCE8QsCd1M03WvjOpURXdRUOupHzLiuSccjKuRkbsbV Zjz4dPh7oStU3b9YzLOMpPgwD2Kt0LzGeVVDcoV3UbjKTeuV4nRDwbnfK1MDkkk0ON 1SGlCyA6Jkt10QAZRdgnXQA2EXv1LVXsrPHhUXS7LOJC/zjNVe3ilYG/p2fYY7qXAo XuxoIhfp9T4wztp6Lc/i8PWYmXdbCxpY9Z3mMZD/oCoxV12FQrFeU0BUvAAno9xZo6 0GeOZu3PuMl0g== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id A7AB0C982F0; Tue, 22 Sep 2026 01:17:57 +0000 (UTC) From: Jaidev Shastri via B4 Relay Date: Mon, 21 Sep 2026 21:17:55 -0400 Subject: [PATCH] pmdomain: renesas: rcar-sysc: publish the external request mask 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" Content-Transfer-Encoding: quoted-printable Message-Id: <20260921-mb-rcar-sysc-v1-1-fb25996bb2f4@vt.edu> X-B4-Tracking: v=1; b=H4sIAELXsWoC/yXM0Q6CMAyF4VchvbYGBg7wVQwX66gyE6dphWgI7 +6Gl1/T86+gLIEVzsUKwkvQ8IwJ1aEAP7l4YwxjMpjS2LI3FT4IxTtB/apHy62lbuybrj5Bmry Er+Gz5y7D3zrTnf07N/IHOWUkcdFP+bRzaY91ijawbT+Df2GbkAAAAA== X-Change-ID: 20260921-mb-rcar-sysc-6e76b8d94835 To: Ulf Hansson , Geert Uytterhoeven , Magnus Damm Cc: linux-pm@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org, Jaidev Shastri X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1790039877; l=2526; i=jaidevshastri@vt.edu; s=20260921; h=from:subject:message-id; bh=/J+UZmfWmy/IxE0tQAJ0EO14IUIFzykt/G670AOHT38=; b=PEN1vUv1FyPiUHVzj+GEzwZkWrshu6uVQzCS8Oh3jmo/jMz+3NIHX13ht9OgFEhnOwxgbOYrU 4mJIv8BfmPECUc5oJ/dDTQnanqIaT5P44PbJfshWBGFaFSHYakXXXBp X-Developer-Key: i=jaidevshastri@vt.edu; a=ed25519; pk=J7+xYJRlTPds+pv5hbqFFRqGCpDeJDzmZT1ggRwj7/0= X-Endpoint-Received: by B4 Relay for jaidevshastri@vt.edu/20260921 with auth_id=1044 X-Original-From: Jaidev Shastri Reply-To: jaidevshastri@vt.edu From: Jaidev Shastri rcar_sysc_pd_init() maps the SYSC registers and stores rcar_sysc_base, rcar_sysc_extmask_offs and rcar_sysc_extmask_val with plain stores, before it registers the power domains. rcar_sysc_power() tests rcar_sysc_extmask_val and then writes through rcar_sysc_base at that offset, from genpd on any CPU. Publish the mask value last with smp_store_release() and read it once with smp_load_acquire() in rcar_sysc_power(). Found with MBCheck, a static herd7-based memory consistency checker. Signed-off-by: Jaidev Shastri --- drivers/pmdomain/renesas/rcar-sysc.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/pmdomain/renesas/rcar-sysc.c b/drivers/pmdomain/renesa= s/rcar-sysc.c index bd7bb9cbd..d0eaaeeb9 100644 --- a/drivers/pmdomain/renesas/rcar-sysc.c +++ b/drivers/pmdomain/renesas/rcar-sysc.c @@ -106,15 +106,19 @@ static int rcar_sysc_power(const struct rcar_sysc_pd = *pd, bool on) unsigned int chan_mask =3D BIT(pd->chan_bit); unsigned int status, k; unsigned long flags; + u32 extmask_val; int ret; =20 spin_lock_irqsave(&rcar_sysc_lock, flags); =20 + /* Pairs with the smp_store_release() in rcar_sysc_pd_init(). */ + extmask_val =3D smp_load_acquire(&rcar_sysc_extmask_val); + /* * Mask external power requests for CPU or 3DG domains */ - if (rcar_sysc_extmask_val) { - iowrite32(rcar_sysc_extmask_val, + if (extmask_val) { + iowrite32(extmask_val, rcar_sysc_base + rcar_sysc_extmask_offs); } =20 @@ -157,7 +161,7 @@ static int rcar_sysc_power(const struct rcar_sysc_pd *p= d, bool on) iowrite32(isr_mask, rcar_sysc_base + SYSCISCR); =20 out: - if (rcar_sysc_extmask_val) + if (extmask_val) iowrite32(0, rcar_sysc_base + rcar_sysc_extmask_offs); =20 spin_unlock_irqrestore(&rcar_sysc_lock, flags); @@ -381,7 +385,12 @@ static int __init rcar_sysc_pd_init(void) =20 /* Optional External Request Mask Register */ rcar_sysc_extmask_offs =3D info->extmask_offs; - rcar_sysc_extmask_val =3D info->extmask_val; + /* + * rcar_sysc_power() tests rcar_sysc_extmask_val and then uses + * rcar_sysc_base and the offset, so publish the value last, with + * release semantics. + */ + smp_store_release(&rcar_sysc_extmask_val, info->extmask_val); =20 domains =3D kzalloc_obj(*domains); if (!domains) { --- base-commit: 93f51579e7df248780214094418f205253383cc5 change-id: 20260921-mb-rcar-sysc-6e76b8d94835 Best regards, -- =20 Jaidev Shastri