libnvdimm, pfn: 'resource'-address and 'size' attributes for pfn devices

Currenty with a raw mode pmem namespace the physical memory address range for
the device can be obtained via /sys/block/pmemX/device/{resource|size}.  Add
similar attributes for pfn instances that takes the struct page memmap and
section padding into account.

Reported-by: Haozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 75a31a7359fb4c57eedad346d2e8623ad23e8da7..254d3bc13f70e22dccbf19709d3e35de8cf78315 100644 (file)
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -205,11 +205,67 @@ static ssize_t namespace_store(struct device *dev,
 }
 static DEVICE_ATTR_RW(namespace);
 
+static ssize_t resource_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+       ssize_t rc;
+
+       device_lock(dev);
+       if (dev->driver) {
+               struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
+               u64 offset = __le64_to_cpu(pfn_sb->dataoff);
+               struct nd_namespace_common *ndns = nd_pfn->ndns;
+               u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
+               struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
+
+               rc = sprintf(buf, "%#llx\n", (unsigned long long) nsio->res.start
+                               + start_pad + offset);
+       } else {
+               /* no address to convey if the pfn instance is disabled */
+               rc = -ENXIO;
+       }
+       device_unlock(dev);
+
+       return rc;
+}
+static DEVICE_ATTR_RO(resource);
+
+static ssize_t size_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+       ssize_t rc;
+
+       device_lock(dev);
+       if (dev->driver) {
+               struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
+               u64 offset = __le64_to_cpu(pfn_sb->dataoff);
+               struct nd_namespace_common *ndns = nd_pfn->ndns;
+               u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
+               u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
+               struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
+
+               rc = sprintf(buf, "%llu\n", (unsigned long long)
+                               resource_size(&nsio->res) - start_pad
+                               - end_trunc - offset);
+       } else {
+               /* no size to convey if the pfn instance is disabled */
+               rc = -ENXIO;
+       }
+       device_unlock(dev);
+
+       return rc;
+}
+static DEVICE_ATTR_RO(size);
+
 static struct attribute *nd_pfn_attributes[] = {
        &dev_attr_mode.attr,
        &dev_attr_namespace.attr,
        &dev_attr_uuid.attr,
        &dev_attr_align.attr,
+       &dev_attr_resource.attr,
+       &dev_attr_size.attr,
        NULL,
 };