| From foo@baz Mon Feb 26 20:55:53 CET 2018 |
| From: Dan Williams <dan.j.williams@intel.com> |
| Date: Fri, 23 Feb 2018 14:06:05 -0800 |
| Subject: libnvdimm, dax: fix 1GB-aligned namespaces vs physical misalignment |
| To: gregkh@linuxfoundation.org |
| Cc: Jane Chu <jane.chu@oracle.com>, linux-kernel@vger.kernel.org, stable@vger.kernel.org |
| Message-ID: <151942356576.21775.15139045279160411096.stgit@dwillia2-desk3.amr.corp.intel.com> |
| |
| From: Dan Williams <dan.j.williams@intel.com> |
| |
| 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: <stable@vger.kernel.org> |
| Fixes: 315c562536c4 ("libnvdimm, pfn: add 'align' attribute...") |
| Reported-and-tested-by: Jane Chu <jane.chu@oracle.com> |
| Signed-off-by: Dan Williams <dan.j.williams@intel.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| 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) |