From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:53998 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725877AbeKLFam (ORCPT ); Mon, 12 Nov 2018 00:30:42 -0500 Subject: patch "devres: Align data[] to ARCH_KMALLOC_MINALIGN" added to driver-core-linus To: alexey.brodkin@synopsys.com, David.Laight@ACULAB.COM, abrodkin@synopsys.com, geert@linux-m68k.org, greg@kroah.com, gregkh@linuxfoundation.org, peterz@infradead.org, stable@vger.kernel.org, tglx@linutronix.de, vgupta@synopsys.com, will.deacon@arm.com From: Date: Sun, 11 Nov 2018 11:41:17 -0800 Message-ID: <1541965277161164@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 devres: Align data[] to ARCH_KMALLOC_MINALIGN to my driver-core git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git in the driver-core-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >>From a66d972465d15b1d89281258805eb8b47d66bd36 Mon Sep 17 00:00:00 2001 From: Alexey Brodkin Date: Wed, 31 Oct 2018 18:25:47 +0300 Subject: devres: Align data[] to ARCH_KMALLOC_MINALIGN Initially we bumped into problem with 32-bit aligned atomic64_t on ARC, see [1]. And then during quite lengthly discussion Peter Z. mentioned ARCH_KMALLOC_MINALIGN which IMHO makes perfect sense. If allocation is done by plain kmalloc() obtained buffer will be ARCH_KMALLOC_MINALIGN aligned and then why buffer obtained via devm_kmalloc() should have any other alignment? This way we at least get the same behavior for both types of allocation. [1] http://lists.infradead.org/pipermail/linux-snps-arc/2018-July/004009.html [2] http://lists.infradead.org/pipermail/linux-snps-arc/2018-July/004036.html Signed-off-by: Alexey Brodkin Cc: Greg Kroah-Hartman Cc: Geert Uytterhoeven Cc: David Laight Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Vineet Gupta Cc: Will Deacon Cc: Greg KH Cc: # 4.8+ Signed-off-by: Greg Kroah-Hartman --- drivers/base/devres.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/base/devres.c b/drivers/base/devres.c index 4aaf00d2098b..e038e2b3b7ea 100644 --- a/drivers/base/devres.c +++ b/drivers/base/devres.c @@ -26,8 +26,14 @@ struct devres_node { struct devres { struct devres_node node; - /* -- 3 pointers */ - unsigned long long data[]; /* guarantee ull alignment */ + /* + * Some archs want to perform DMA into kmalloc caches + * and need a guaranteed alignment larger than + * the alignment of a 64-bit integer. + * Thus we use ARCH_KMALLOC_MINALIGN here and get exactly the same + * buffer alignment as if it was allocated by plain kmalloc(). + */ + u8 __aligned(ARCH_KMALLOC_MINALIGN) data[]; }; struct devres_group { -- 2.19.1