4.9-stable review patch. If anyone has any objections, please let me know.
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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)