From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:34526 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752210AbeBZUWx (ORCPT ); Mon, 26 Feb 2018 15:22:53 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Williams Subject: [PATCH 4.9 36/39] libnvdimm, dax: fix 1GB-aligned namespaces vs physical misalignment Date: Mon, 26 Feb 2018 21:20:57 +0100 Message-Id: <20180226201645.252595532@linuxfoundation.org> In-Reply-To: <20180226201643.660109883@linuxfoundation.org> References: <20180226201643.660109883@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Williams commit 41fce90f26333c4fa82e8e43b9ace86c4e8a0120 upstream. The following namespace configuration attempt: # ndctl create-namespace -e namespace0.0 -m devdax -a 1G -f libndctl: ndctl_dax_enable: dax0.1: failed to enable Error: namespace0.0: failed to enable failed to reconfigure namespace: No such device or address ...fails when the backing memory range is not physically aligned to 1G: # cat /proc/iomem | grep Persistent 210000000-30fffffff : Persistent Memory (legacy) In the above example the 4G persistent memory range starts and ends on a 256MB boundary. We handle this case correctly when needing to handle cases that violate section alignment (128MB) collisions against "System RAM", and we simply need to extend that padding/truncation for the 1GB alignment use case. Cc: Fixes: 315c562536c4 ("libnvdimm, pfn: add 'align' attribute...") Reported-and-tested-by: Jane Chu Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman --- drivers/nvdimm/pfn_devs.c | 15 ++++++++++++--- include/linux/kernel.h | 1 + 2 files changed, 13 insertions(+), 3 deletions(-) --- a/drivers/nvdimm/pfn_devs.c +++ b/drivers/nvdimm/pfn_devs.c @@ -563,6 +563,12 @@ static struct vmem_altmap *__nvdimm_setu return altmap; } +static u64 phys_pmem_align_down(struct nd_pfn *nd_pfn, u64 phys) +{ + return min_t(u64, PHYS_SECTION_ALIGN_DOWN(phys), + ALIGN_DOWN(phys, nd_pfn->align)); +} + static int nd_pfn_init(struct nd_pfn *nd_pfn) { u32 dax_label_reserve = is_nd_dax(&nd_pfn->dev) ? SZ_128K : 0; @@ -618,13 +624,16 @@ static int nd_pfn_init(struct nd_pfn *nd start = nsio->res.start; size = PHYS_SECTION_ALIGN_UP(start + size) - start; if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM, - IORES_DESC_NONE) == REGION_MIXED) { + IORES_DESC_NONE) == REGION_MIXED + || !IS_ALIGNED(start + resource_size(&nsio->res), + nd_pfn->align)) { size = resource_size(&nsio->res); - end_trunc = start + size - PHYS_SECTION_ALIGN_DOWN(start + size); + end_trunc = start + size - phys_pmem_align_down(nd_pfn, + start + size); } if (start_pad + end_trunc) - dev_info(&nd_pfn->dev, "%s section collision, truncate %d bytes\n", + dev_info(&nd_pfn->dev, "%s alignment collision, truncate %d bytes\n", dev_name(&ndns->dev), start_pad + end_trunc); /* --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -46,6 +46,7 @@ #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x)) #define ALIGN(x, a) __ALIGN_KERNEL((x), (a)) +#define ALIGN_DOWN(x, a) __ALIGN_KERNEL((x) - ((a) - 1), (a)) #define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask)) #define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a))) #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)