libnvdimm, pfn: add 'align' attribute, default to HPAGE_SIZE

[linux-beck.git] / drivers / nvdimm / pfn_devs.c

diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 613ffcca6ecbb9466fc31d2c3d83ac5288b1917f..95ecd7b0fab3a91145dd50c3d9d3fd128aa86ff0 100644 (file)
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -103,6 +103,52 @@ static ssize_t mode_store(struct device *dev,
 }
 static DEVICE_ATTR_RW(mode);
 
+static ssize_t align_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+
+       return sprintf(buf, "%lx\n", nd_pfn->align);
+}
+
+static ssize_t __align_store(struct nd_pfn *nd_pfn, const char *buf)
+{
+       unsigned long val;
+       int rc;
+
+       rc = kstrtoul(buf, 0, &val);
+       if (rc)
+               return rc;
+
+       if (!is_power_of_2(val) || val < PAGE_SIZE || val > SZ_1G)
+               return -EINVAL;
+
+       if (nd_pfn->dev.driver)
+               return -EBUSY;
+       else
+               nd_pfn->align = val;
+
+       return 0;
+}
+
+static ssize_t align_store(struct device *dev,
+               struct device_attribute *attr, const char *buf, size_t len)
+{
+       struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+       ssize_t rc;
+
+       device_lock(dev);
+       nvdimm_bus_lock(dev);
+       rc = __align_store(nd_pfn, buf);
+       dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
+                       rc, buf, buf[len - 1] == '\n' ? "" : "\n");
+       nvdimm_bus_unlock(dev);
+       device_unlock(dev);
+
+       return rc ? rc : len;
+}
+static DEVICE_ATTR_RW(align);
+
 static ssize_t uuid_show(struct device *dev,
                struct device_attribute *attr, char *buf)
 {
@@ -164,6 +210,7 @@ static struct attribute *nd_pfn_attributes[] = {
        &dev_attr_mode.attr,
        &dev_attr_namespace.attr,
        &dev_attr_uuid.attr,
+       &dev_attr_align.attr,
        NULL,
 };
 
@@ -199,6 +246,7 @@ static struct device *__nd_pfn_create(struct nd_region *nd_region,
        }
 
        nd_pfn->mode = PFN_MODE_NONE;
+       nd_pfn->align = HPAGE_SIZE;
        dev = &nd_pfn->dev;
        dev_set_name(dev, "pfn%d.%d", nd_region->id, nd_pfn->id);
        dev->parent = &nd_region->dev;
@@ -269,6 +317,12 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
                        return -EINVAL;
        }
 
+       if (nd_pfn->align > nvdimm_namespace_capacity(ndns)) {
+               dev_err(&nd_pfn->dev, "alignment: %lx exceeds capacity %llx\n",
+                               nd_pfn->align, nvdimm_namespace_capacity(ndns));
+               return -EINVAL;
+       }
+
        /*
         * These warnings are verbose because they can only trigger in
         * the case where the physical address alignment of the
@@ -283,6 +337,13 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
                return -EBUSY;
        }
 
+       nd_pfn->align = 1UL << ilog2(offset);
+       if (!is_power_of_2(offset) || offset < PAGE_SIZE) {
+               dev_err(&nd_pfn->dev, "bad offset: %#llx dax disabled\n",
+                               offset);
+               return -ENXIO;
+       }
+
        return 0;
 }
 EXPORT_SYMBOL(nd_pfn_validate);