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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CB553C54EED for ; Mon, 30 Jan 2023 14:00:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236821AbjA3OAV (ORCPT ); Mon, 30 Jan 2023 09:00:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41232 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236835AbjA3OAR (ORCPT ); Mon, 30 Jan 2023 09:00:17 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5CE811116F for ; Mon, 30 Jan 2023 06:00:00 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 02539B81154 for ; Mon, 30 Jan 2023 13:59:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 48410C433EF; Mon, 30 Jan 2023 13:59:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675087196; bh=Cy+rMliy731X8nCrmtYnLpIciONNviBvc9cYiKPKdqI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CxdhmPivv+cm5xMpzaBmBsTQe262mre1RgtnIk76d5D9KTKnnhmo5pCnrRVMjEcM6 dyZ+9gDGkggQq4ZtSG0+WVa0Wpy/S5+StBObVh1zrZV402mAij/gygv7BnmP6kTXWn bD+1l6BtxcVDlB3E0s6IdMzWuEmLGAM+ZjFQUKFI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Pilmore , Vinod Koul , Sasha Levin Subject: [PATCH 6.1 128/313] ptdma: pt_core_execute_cmd() should use spinlock Date: Mon, 30 Jan 2023 14:49:23 +0100 Message-Id: <20230130134342.618841840@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230130134336.532886729@linuxfoundation.org> References: <20230130134336.532886729@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Pilmore [ Upstream commit 95e5fda3b5f9ed8239b145da3fa01e641cf5d53c ] The interrupt handler (pt_core_irq_handler()) of the ptdma driver can be called from interrupt context. The code flow in this function can lead down to pt_core_execute_cmd() which will attempt to grab a mutex, which is not appropriate in interrupt context and ultimately leads to a kernel panic. The fix here changes this mutex to a spinlock, which has been verified to resolve the issue. Fixes: fa5d823b16a9 ("dmaengine: ptdma: Initial driver for the AMD PTDMA") Signed-off-by: Eric Pilmore Link: https://lore.kernel.org/r/20230119033907.35071-1-epilmore@gigaio.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin --- drivers/dma/ptdma/ptdma-dev.c | 7 ++++--- drivers/dma/ptdma/ptdma.h | 2 +- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/dma/ptdma/ptdma-dev.c b/drivers/dma/ptdma/ptdma-dev.c index 377da23012ac..a2bf13ff18b6 100644 --- a/drivers/dma/ptdma/ptdma-dev.c +++ b/drivers/dma/ptdma/ptdma-dev.c @@ -71,12 +71,13 @@ static int pt_core_execute_cmd(struct ptdma_desc *desc, struct pt_cmd_queue *cmd bool soc = FIELD_GET(DWORD0_SOC, desc->dw0); u8 *q_desc = (u8 *)&cmd_q->qbase[cmd_q->qidx]; u32 tail; + unsigned long flags; if (soc) { desc->dw0 |= FIELD_PREP(DWORD0_IOC, desc->dw0); desc->dw0 &= ~DWORD0_SOC; } - mutex_lock(&cmd_q->q_mutex); + spin_lock_irqsave(&cmd_q->q_lock, flags); /* Copy 32-byte command descriptor to hw queue. */ memcpy(q_desc, desc, 32); @@ -91,7 +92,7 @@ static int pt_core_execute_cmd(struct ptdma_desc *desc, struct pt_cmd_queue *cmd /* Turn the queue back on using our cached control register */ pt_start_queue(cmd_q); - mutex_unlock(&cmd_q->q_mutex); + spin_unlock_irqrestore(&cmd_q->q_lock, flags); return 0; } @@ -199,7 +200,7 @@ int pt_core_init(struct pt_device *pt) cmd_q->pt = pt; cmd_q->dma_pool = dma_pool; - mutex_init(&cmd_q->q_mutex); + spin_lock_init(&cmd_q->q_lock); /* Page alignment satisfies our needs for N <= 128 */ cmd_q->qsize = Q_SIZE(Q_DESC_SIZE); diff --git a/drivers/dma/ptdma/ptdma.h b/drivers/dma/ptdma/ptdma.h index d093c43b7d13..21b4bf895200 100644 --- a/drivers/dma/ptdma/ptdma.h +++ b/drivers/dma/ptdma/ptdma.h @@ -196,7 +196,7 @@ struct pt_cmd_queue { struct ptdma_desc *qbase; /* Aligned queue start address (per requirement) */ - struct mutex q_mutex ____cacheline_aligned; + spinlock_t q_lock ____cacheline_aligned; unsigned int qidx; unsigned int qsize; -- 2.39.0