From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:53172 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752263AbdLKV4o (ORCPT ); Mon, 11 Dec 2017 16:56:44 -0500 Subject: Patch "scsi: use dma_get_cache_alignment() as minimum DMA alignment" has been added to the 4.14-stable tree To: chenhc@lemote.com, gregkh@linuxfoundation.org, hch@lst.de, martin.petersen@oracle.com Cc: , From: Date: Mon, 11 Dec 2017 22:54:05 +0100 Message-ID: <151302924518188@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled scsi: use dma_get_cache_alignment() as minimum DMA alignment to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: scsi-use-dma_get_cache_alignment-as-minimum-dma-alignment.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 90addc6b3c9cda0146fbd62a08e234c2b224a80c Mon Sep 17 00:00:00 2001 From: Huacai Chen Date: Tue, 21 Nov 2017 14:23:38 +0100 Subject: scsi: use dma_get_cache_alignment() as minimum DMA alignment From: Huacai Chen commit 90addc6b3c9cda0146fbd62a08e234c2b224a80c upstream. In non-coherent DMA mode, kernel uses cache flushing operations to maintain I/O coherency, so scsi's block queue should be aligned to the value returned by dma_get_cache_alignment(). Otherwise, If a DMA buffer and a kernel structure share a same cache line, and if the kernel structure has dirty data, cache_invalidate (no writeback) will cause data corruption. Signed-off-by: Huacai Chen [hch: rebased and updated the comment and changelog] Signed-off-by: Christoph Hellwig Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/scsi_lib.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -2126,11 +2126,13 @@ void __scsi_init_queue(struct Scsi_Host q->limits.cluster = 0; /* - * set a reasonable default alignment on word boundaries: the - * host and device may alter it using - * blk_queue_update_dma_alignment() later. + * Set a reasonable default alignment: The larger of 32-byte (dword), + * which is a common minimum for HBAs, and the minimum DMA alignment, + * which is set by the platform. + * + * Devices that require a bigger alignment can increase it later. */ - blk_queue_dma_alignment(q, 0x03); + blk_queue_dma_alignment(q, max(4, dma_get_cache_alignment()) - 1); } EXPORT_SYMBOL_GPL(__scsi_init_queue); Patches currently in stable-queue which might be from chenhc@lemote.com are queue-4.14/scsi-use-dma_get_cache_alignment-as-minimum-dma-alignment.patch queue-4.14/scsi-libsas-align-sata_device-s-rps_resp-on-a-cacheline.patch