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 CAE221C08 for ; Wed, 28 Dec 2022 16:35:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3361EC433F0; Wed, 28 Dec 2022 16:35:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1672245337; bh=STWR08XNfDHGIgwVqoMjIcCEx47HDiY/pzVuziTSxrU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GdVAa7NrNnoSeaOzb5qpXCPyj1GWCBERpxghgD6jPXUl7Z6J60BoM/08PdTUH1tSo fVvS5wqJkDn0Y4D0ZgvrT2fmAYs4TmlA+sMvrpRJTdvlwe5TKUjJvfwDCVdqu2Mnpo +TJyZaAqDjJD++PMqVXfG/cVlu/2/rfMwclFFU6A= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Conor Dooley , Palmer Dabbelt , Jassi Brar , Sasha Levin Subject: [PATCH 6.0 0875/1073] mailbox: mpfs: read the system controllers status Date: Wed, 28 Dec 2022 15:41:03 +0100 Message-Id: <20221228144351.790957744@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20221228144328.162723588@linuxfoundation.org> References: <20221228144328.162723588@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Conor Dooley [ Upstream commit ab47d0bfdf88faac0eb02749e5bfaa306e004300 ] Some services explicitly return an error code in their response, but others rely on the system controller to set a status in its status register. The meaning of the bits varies based on what service is requested, so pass it back up to the driver that requested the service in the first place. The field in the message struct already existed, but was unused until now. If the system controller is busy, in which case we should never actually be in the interrupt handler, or if the service fails the mailbox itself should not be read. Callers should check the status before operating on the response. There's an existing, but unused, #define for the mailbox mask - but it was incorrect. It was doing a GENMASK_ULL(32, 16) which should've just been a GENMASK(31, 16), so fix that up and start using it. Fixes: 83d7b1560810 ("mbox: add polarfire soc system controller mailbox") Signed-off-by: Conor Dooley Reviewed-by: Palmer Dabbelt Signed-off-by: Jassi Brar Signed-off-by: Sasha Levin --- drivers/mailbox/mailbox-mpfs.c | 31 ++++++++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-) diff --git a/drivers/mailbox/mailbox-mpfs.c b/drivers/mailbox/mailbox-mpfs.c index cfacb3f320a6..853901acaeec 100644 --- a/drivers/mailbox/mailbox-mpfs.c +++ b/drivers/mailbox/mailbox-mpfs.c @@ -2,7 +2,7 @@ /* * Microchip PolarFire SoC (MPFS) system controller/mailbox controller driver * - * Copyright (c) 2020 Microchip Corporation. All rights reserved. + * Copyright (c) 2020-2022 Microchip Corporation. All rights reserved. * * Author: Conor Dooley * @@ -56,7 +56,7 @@ #define SCB_STATUS_NOTIFY_MASK BIT(SCB_STATUS_NOTIFY) #define SCB_STATUS_POS (16) -#define SCB_STATUS_MASK GENMASK_ULL(SCB_STATUS_POS + SCB_MASK_WIDTH, SCB_STATUS_POS) +#define SCB_STATUS_MASK GENMASK(SCB_STATUS_POS + SCB_MASK_WIDTH - 1, SCB_STATUS_POS) struct mpfs_mbox { struct mbox_controller controller; @@ -130,13 +130,38 @@ static void mpfs_mbox_rx_data(struct mbox_chan *chan) struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv; struct mpfs_mss_response *response = mbox->response; u16 num_words = ALIGN((response->resp_size), (4)) / 4U; - u32 i; + u32 i, status; if (!response->resp_msg) { dev_err(mbox->dev, "failed to assign memory for response %d\n", -ENOMEM); return; } + /* + * The status is stored in bits 31:16 of the SERVICES_SR register. + * It is only valid when BUSY == 0. + * We should *never* get an interrupt while the controller is + * still in the busy state. If we do, something has gone badly + * wrong & the content of the mailbox would not be valid. + */ + if (mpfs_mbox_busy(mbox)) { + dev_err(mbox->dev, "got an interrupt but system controller is busy\n"); + response->resp_status = 0xDEAD; + return; + } + + status = readl_relaxed(mbox->ctrl_base + SERVICES_SR_OFFSET); + + /* + * If the status of the individual servers is non-zero, the service has + * failed. The contents of the mailbox at this point are not be valid, + * so don't bother reading them. Set the status so that the driver + * implementing the service can handle the result. + */ + response->resp_status = (status & SCB_STATUS_MASK) >> SCB_STATUS_POS; + if (response->resp_status) + return; + if (!mpfs_mbox_busy(mbox)) { for (i = 0; i < num_words; i++) { response->resp_msg[i] = -- 2.35.1