@@ -230,14 +230,15 @@ static ssize_t region_size_show(struct device *dev,
static struct device_attribute dev_attr_region_size = __ATTR(size, 0444,
region_size_show, NULL);
-static ssize_t align_show(struct device *dev,
+static ssize_t region_align_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct dax_region *dax_region = dev_get_drvdata(dev);
return sprintf(buf, "%u\n", dax_region->align);
}
-static DEVICE_ATTR_RO(align);
+static struct device_attribute dev_attr_region_align =
+ __ATTR(align, 0400, region_align_show, NULL);
#define for_each_dax_region_resource(dax_region, res) \
for (res = (dax_region)->res.child; res; res = res->sibling)
@@ -488,7 +489,7 @@ static umode_t dax_region_visible(struct kobject *kobj, struct attribute *a,
static struct attribute *dax_region_attributes[] = {
&dev_attr_available_size.attr,
&dev_attr_region_size.attr,
- &dev_attr_align.attr,
+ &dev_attr_region_align.attr,
&dev_attr_create.attr,
&dev_attr_seed.attr,
&dev_attr_delete.attr,
@@ -858,15 +859,13 @@ static ssize_t size_show(struct device *dev,
return sprintf(buf, "%llu\n", size);
}
-static bool alloc_is_aligned(struct dax_region *dax_region,
- resource_size_t size)
+static bool alloc_is_aligned(struct dev_dax *dev_dax, resource_size_t size)
{
/*
* The minimum mapping granularity for a device instance is a
* single subsection, unless the arch says otherwise.
*/
- return IS_ALIGNED(size, max_t(unsigned long, dax_region->align,
- memremap_compat_align()));
+ return IS_ALIGNED(size, max_t(unsigned long, dev_dax->align, memremap_compat_align()));
}
static int dev_dax_shrink(struct dev_dax *dev_dax, resource_size_t size)
@@ -961,7 +960,7 @@ static ssize_t dev_dax_resize(struct dax_region *dax_region,
return dev_dax_shrink(dev_dax, size);
to_alloc = size - dev_size;
- if (dev_WARN_ONCE(dev, !alloc_is_aligned(dax_region, to_alloc),
+ if (dev_WARN_ONCE(dev, !alloc_is_aligned(dev_dax, to_alloc),
"resize of %pa misaligned\n", &to_alloc))
return -ENXIO;
@@ -1025,7 +1024,7 @@ static ssize_t size_store(struct device *dev, struct device_attribute *attr,
if (rc)
return rc;
- if (!alloc_is_aligned(dax_region, val)) {
+ if (!alloc_is_aligned(dev_dax, val)) {
dev_dbg(dev, "%s: size: %lld misaligned\n", __func__, val);
return -EINVAL;
}
@@ -1044,6 +1043,78 @@ static ssize_t size_store(struct device *dev, struct device_attribute *attr,
}
static DEVICE_ATTR_RW(size);
+static ssize_t align_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct dev_dax *dev_dax = to_dev_dax(dev);
+
+ return sprintf(buf, "%d\n", dev_dax->align);
+}
+
+static ssize_t dev_dax_validate_align(struct dev_dax *dev_dax)
+{
+ resource_size_t dev_size = dev_dax_size(dev_dax);
+ struct device *dev = &dev_dax->dev;
+ int i;
+
+ if (dev_size > 0 && !alloc_is_aligned(dev_dax, dev_size)) {
+ dev_dbg(dev, "%s: align %u invalid for size %pa\n",
+ __func__, dev_dax->align, &dev_size);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < dev_dax->nr_range; i++) {
+ size_t len = range_len(&dev_dax->ranges[i].range);
+
+ if (!alloc_is_aligned(dev_dax, len)) {
+ dev_dbg(dev, "%s: align %u invalid for range %d\n",
+ __func__, dev_dax->align, i);
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+static ssize_t align_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct dev_dax *dev_dax = to_dev_dax(dev);
+ struct dax_region *dax_region = dev_dax->region;
+ unsigned long val, align_save;
+ ssize_t rc;
+
+ rc = kstrtoul(buf, 0, &val);
+ if (rc)
+ return -ENXIO;
+
+ if (!dax_align_valid(val))
+ return -EINVAL;
+
+ device_lock(dax_region->dev);
+ if (!dax_region->dev->driver) {
+ device_unlock(dax_region->dev);
+ return -ENXIO;
+ }
+
+ device_lock(dev);
+ if (dev->driver) {
+ rc = -EBUSY;
+ goto out_unlock;
+ }
+
+ align_save = dev_dax->align;
+ dev_dax->align = val;
+ rc = dev_dax_validate_align(dev_dax);
+ if (rc)
+ dev_dax->align = align_save;
+out_unlock:
+ device_unlock(dev);
+ device_unlock(dax_region->dev);
+ return rc == 0 ? len : rc;
+}
+static DEVICE_ATTR_RW(align);
+
static int dev_dax_target_node(struct dev_dax *dev_dax)
{
struct dax_region *dax_region = dev_dax->region;
@@ -1104,7 +1175,8 @@ static umode_t dev_dax_visible(struct kobject *kobj, struct attribute *a, int n)
return 0;
if (a == &dev_attr_numa_node.attr && !IS_ENABLED(CONFIG_NUMA))
return 0;
- if (a == &dev_attr_size.attr && is_static(dax_region))
+ if ((a == &dev_attr_align.attr ||
+ a == &dev_attr_size.attr) && is_static(dax_region))
return 0444;
return a->mode;
}
@@ -1113,6 +1185,7 @@ static struct attribute *dev_dax_attributes[] = {
&dev_attr_modalias.attr,
&dev_attr_size.attr,
&dev_attr_target_node.attr,
+ &dev_attr_align.attr,
&dev_attr_resource.attr,
&dev_attr_numa_node.attr,
NULL,
@@ -87,4 +87,22 @@ static inline struct dax_mapping *to_dax_mapping(struct device *dev)
}
phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff, unsigned long size);
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static inline bool dax_align_valid(unsigned long align)
+{
+ if (align == PUD_SIZE && IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD))
+ return true;
+ if (align == PMD_SIZE && has_transparent_hugepage())
+ return true;
+ if (align == PAGE_SIZE)
+ return true;
+ return false;
+}
+#else
+static inline bool dax_align_valid(unsigned long align)
+{
+ return align == PAGE_SIZE;
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif