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@xxxxxxxxxxxxxxx>
Fixes: 315c562536c4 ("libnvdimm, pfn: add 'align' attribute...")
Reported-and-tested-by: Jane Chu <jane.chu@xxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/nvdimm/pfn_devs.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 65cc171c721d..5ba9ab7af736 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -582,6 +582,12 @@ static struct vmem_altmap *__nvdimm_setup_pfn(struct nd_pfn *nd_pfn,
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;
@@ -637,13 +643,16 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
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);
/*