From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754790Ab2IQAvf (ORCPT ); Sun, 16 Sep 2012 20:51:35 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33941 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754690Ab2IQAva (ORCPT ); Sun, 16 Sep 2012 20:51:30 -0400 Message-Id: <20120917003632.215097822@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 17 Sep 2012 01:37:08 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Ronny Hegewald , Stefano Panella , David Vrabel , Konrad Rzeszutek Wilk Subject: [ 043/135] xen: Use correct masking in xen_swiotlb_alloc_coherent. In-Reply-To: <20120917003625.784119135@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ronny Hegewald commit b5031ed1be0aa419250557123633453753181643 upstream. When running 32-bit pvops-dom0 and a driver tries to allocate a coherent DMA-memory the xen swiotlb-implementation returned memory beyond 4GB. The underlaying reason is that if the supplied driver passes in a DMA_BIT_MASK(64) ( hwdev->coherent_dma_mask is set to 0xffffffffffffffff) our dma_mask will be u64 set to 0xffffffffffffffff even if we set it to DMA_BIT_MASK(32) previously. Meaning we do not reset the upper bits. By using the dma_alloc_coherent_mask function - it does the proper casting and we get 0xfffffffff. This caused not working sound on a system with 4 GB and a 64-bit compatible sound-card with sets the DMA-mask to 64bit. On bare-metal and the forward-ported xen-dom0 patches from OpenSuse a coherent DMA-memory is always allocated inside the 32-bit address-range by calling dma_alloc_coherent_mask. This patch adds the same functionality to xen swiotlb and is a rebase of the original patch from Ronny Hegewald which never got upstream b/c the underlaying reason was not understood until now. The original email with the original patch is in: http://old-list-archives.xen.org/archives/html/xen-devel/2010-02/msg00038.html the original thread from where the discussion started is in: http://old-list-archives.xen.org/archives/html/xen-devel/2010-01/msg00928.html Signed-off-by: Ronny Hegewald Signed-off-by: Stefano Panella Acked-By: David Vrabel Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Ben Hutchings --- drivers/xen/swiotlb-xen.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 1afb4fb..4d51948 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -232,7 +232,7 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, return ret; if (hwdev && hwdev->coherent_dma_mask) - dma_mask = hwdev->coherent_dma_mask; + dma_mask = dma_alloc_coherent_mask(hwdev, flags); phys = virt_to_phys(ret); dev_addr = xen_phys_to_bus(phys);