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 X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 17979C3A5A2 for ; Sun, 22 Sep 2019 19:36:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E3235206B6 for ; Sun, 22 Sep 2019 19:36:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569181014; bh=iupxWFpcY6/cgaLlrAWuYCcnrImMYlOV5CQiGwgF2WE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=sIebX6ukrpadVt+Sa6O8Mwu8VdjaREW0G5NUubNTNWg5JJMMY1AAva48Zpoup0hhD lpsJ3ysDEzY7qRV1U9SHWAHTAlqlAluY44xjoNBoHyj2d3aMVws17rGft2yDepIgKV WRHHgZDQ+CKMmL6PbYjWwz7aPT3zzLnCVEsWsfgs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389784AbfIVSqC (ORCPT ); Sun, 22 Sep 2019 14:46:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:41846 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389732AbfIVSp7 (ORCPT ); Sun, 22 Sep 2019 14:45:59 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5343920665; Sun, 22 Sep 2019 18:45:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569177959; bh=iupxWFpcY6/cgaLlrAWuYCcnrImMYlOV5CQiGwgF2WE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MMap3sWSttfOfZOEuvjJL/3AO9UgMgf29aD3254eduzo7ywV9QC2XPM0HTjbEDEXf TEP3iEOJRNlzumakaGB+cdYoGmIudvPABGI/H+CAlAc/CewdKID6/CVXDLpa2+anxo MuyskYMZdmiMjv/cg5Sk4XgcR0K/1ctAPPwrPs0o= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sudeep Holla , Jim Quinlan , Sasha Levin , linux-arm-kernel@lists.infradead.org Subject: [PATCH AUTOSEL 5.3 063/203] firmware: arm_scmi: Check if platform has released shmem before using Date: Sun, 22 Sep 2019 14:41:29 -0400 Message-Id: <20190922184350.30563-63-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190922184350.30563-1-sashal@kernel.org> References: <20190922184350.30563-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sudeep Holla [ Upstream commit 9dc34d635c67e57051853855c43249408641a5ab ] Sometimes platfom may take too long to respond to the command and OS might timeout before platform transfer the ownership of the shared memory region to the OS with the response. Since the mailbox channel associated with the channel is freed and new commands are dispatch on the same channel, OS needs to wait until it gets back the ownership. If not, either OS may end up overwriting the platform response for the last command(which is fine as OS timed out that command) or platform might overwrite the payload for the next command with the response for the old. The latter is problematic as platform may end up interpretting the response as the payload. In order to avoid such race, let's wait until the OS gets back the ownership before we prepare the shared memory with the payload for the next command. Reported-by: Jim Quinlan Signed-off-by: Sudeep Holla Signed-off-by: Sasha Levin --- drivers/firmware/arm_scmi/driver.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index b5bc4c7a8fab2..b49c9e6f4bf10 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -271,6 +271,14 @@ static void scmi_tx_prepare(struct mbox_client *cl, void *m) struct scmi_chan_info *cinfo = client_to_scmi_chan_info(cl); struct scmi_shared_mem __iomem *mem = cinfo->payload; + /* + * Ideally channel must be free by now unless OS timeout last + * request and platform continued to process the same, wait + * until it releases the shared memory, otherwise we may endup + * overwriting its response with new message payload or vice-versa + */ + spin_until_cond(ioread32(&mem->channel_status) & + SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE); /* Mark channel busy + clear error */ iowrite32(0x0, &mem->channel_status); iowrite32(t->hdr.poll_completion ? 0 : SCMI_SHMEM_FLAG_INTR_ENABLED, -- 2.20.1 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 X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 37397C4740C for ; Sun, 22 Sep 2019 18:46:12 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 12154214AF for ; Sun, 22 Sep 2019 18:46:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="mM+j29un"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="MMap3sWS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 12154214AF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=8W/LQ0zYj8n3jhkd20oNiyn6JT/7QCOMfzXPgfnHJLo=; b=mM+j29un+UR5mN cGwg5tNFa0KFIIRG5372LdOrynk7QfYhE2ZmJqDQi/Zo0xO0fux6M5zPiClnS8uwhFu5ffZF7U4iy Qdm0jkZewP7ccuc9RBTs3cTk8LU8f6o2UhCgNmmJRRiVHlb7RQ04rRNG/pVxTvoayqS8Kfd8aAM/9 5bEvPh+795GUy+zQygMZ7KhSOyoqKuQEmSWStz9JrCYcRKYcvS+P6tsiuoseJF7Zi4XUkaW0Ow5t1 8d61+NHEjlEryr8QbqPz2igys64ApublMUDVvjOkK5avX4RlsAQnJ+iQ69h1o4Dbi4VBadNBmrVOW 8KO5PN9ed8qf4rh27hig==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iC6ry-0006bZ-R0; Sun, 22 Sep 2019 18:46:02 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1iC6rv-0006Zz-AA for linux-arm-kernel@lists.infradead.org; Sun, 22 Sep 2019 18:46:00 +0000 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5343920665; Sun, 22 Sep 2019 18:45:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569177959; bh=iupxWFpcY6/cgaLlrAWuYCcnrImMYlOV5CQiGwgF2WE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MMap3sWSttfOfZOEuvjJL/3AO9UgMgf29aD3254eduzo7ywV9QC2XPM0HTjbEDEXf TEP3iEOJRNlzumakaGB+cdYoGmIudvPABGI/H+CAlAc/CewdKID6/CVXDLpa2+anxo MuyskYMZdmiMjv/cg5Sk4XgcR0K/1ctAPPwrPs0o= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 5.3 063/203] firmware: arm_scmi: Check if platform has released shmem before using Date: Sun, 22 Sep 2019 14:41:29 -0400 Message-Id: <20190922184350.30563-63-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190922184350.30563-1-sashal@kernel.org> References: <20190922184350.30563-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190922_114559_373128_D2E24D43 X-CRM114-Status: GOOD ( 11.83 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sasha Levin , linux-arm-kernel@lists.infradead.org, Jim Quinlan , Sudeep Holla Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Sudeep Holla [ Upstream commit 9dc34d635c67e57051853855c43249408641a5ab ] Sometimes platfom may take too long to respond to the command and OS might timeout before platform transfer the ownership of the shared memory region to the OS with the response. Since the mailbox channel associated with the channel is freed and new commands are dispatch on the same channel, OS needs to wait until it gets back the ownership. If not, either OS may end up overwriting the platform response for the last command(which is fine as OS timed out that command) or platform might overwrite the payload for the next command with the response for the old. The latter is problematic as platform may end up interpretting the response as the payload. In order to avoid such race, let's wait until the OS gets back the ownership before we prepare the shared memory with the payload for the next command. Reported-by: Jim Quinlan Signed-off-by: Sudeep Holla Signed-off-by: Sasha Levin --- drivers/firmware/arm_scmi/driver.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index b5bc4c7a8fab2..b49c9e6f4bf10 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -271,6 +271,14 @@ static void scmi_tx_prepare(struct mbox_client *cl, void *m) struct scmi_chan_info *cinfo = client_to_scmi_chan_info(cl); struct scmi_shared_mem __iomem *mem = cinfo->payload; + /* + * Ideally channel must be free by now unless OS timeout last + * request and platform continued to process the same, wait + * until it releases the shared memory, otherwise we may endup + * overwriting its response with new message payload or vice-versa + */ + spin_until_cond(ioread32(&mem->channel_status) & + SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE); /* Mark channel busy + clear error */ iowrite32(0x0, &mem->channel_status); iowrite32(t->hdr.poll_completion ? 0 : SCMI_SHMEM_FLAG_INTR_ENABLED, -- 2.20.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel