Merge tag 'libnvdimm-for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dan Williams:
 "The bulk of this has been in multiple -next releases. There were a few
  late breaking fixes and small features that got added in the last
  couple days, but the whole set has received a build success
  notification from the kbuild robot.

  Change summary:

   - Region media error reporting: A libnvdimm region device is the
     parent to one or more namespaces. To date, media errors have been
     reported via the "badblocks" attribute attached to pmem block
     devices for namespaces in "raw" or "memory" mode. Given that
     namespaces can be in "device-dax" or "btt-sector" mode this new
     interface reports media errors generically, i.e. independent of
     namespace modes or state.

     This subsequently allows userspace tooling to craft "ACPI 6.1
     Section 9.20.7.6 Function Index 4 - Clear Uncorrectable Error"
     requests and submit them via the ioctl path for NVDIMM root bus
     devices.

   - Introduce 'struct dax_device' and 'struct dax_operations': Prompted
     by a request from Linus and feedback from Christoph this allows for
     dax capable drivers to publish their own custom dax operations.
     This fixes the broken assumption that all dax operations are
     related to a persistent memory device, and makes it easier for
     other architectures and platforms to add customized persistent
     memory support.

   - 'libnvdimm' core updates: A new "deep_flush" sysfs attribute is
     available for storage appliance applications to manually trigger
     memory controllers to drain write-pending buffers that would
     otherwise be flushed automatically by the platform ADR
     (asynchronous-DRAM-refresh) mechanism at a power loss event.
     Support for "locked" DIMMs is included to prevent namespaces from
     surfacing when the namespace label data area is locked. Finally,
     fixes for various reported deadlocks and crashes, also tagged for
     -stable.

   - ACPI / nfit driver updates: General updates of the nfit driver to
     add DSM command overrides, ACPI 6.1 health state flags support, DSM
     payload debug available by default, and various fixes.

  Acknowledgements that came after the branch was pushed:

   - commmit 565851c972 "device-dax: fix sysfs attribute deadlock":
     Tested-by: Yi Zhang <yizhan@redhat.com>

   - commit 23f4984483 "libnvdimm: rework region badblocks clearing"
     Tested-by: Toshi Kani <toshi.kani@hpe.com>"

* tag 'libnvdimm-for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (52 commits)
  libnvdimm, pfn: fix 'npfns' vs section alignment
  libnvdimm: handle locked label storage areas
  libnvdimm: convert NDD_ flags to use bitops, introduce NDD_LOCKED
  brd: fix uninitialized use of brd->dax_dev
  block, dax: use correct format string in bdev_dax_supported
  device-dax: fix sysfs attribute deadlock
  libnvdimm: restore "libnvdimm: band aid btt vs clear poison locking"
  libnvdimm: fix nvdimm_bus_lock() vs device_lock() ordering
  libnvdimm: rework region badblocks clearing
  acpi, nfit: kill ACPI_NFIT_DEBUG
  libnvdimm: fix clear length of nvdimm_forget_poison()
  libnvdimm, pmem: fix a NULL pointer BUG in nd_pmem_notify
  libnvdimm, region: sysfs trigger for nvdimm_flush()
  libnvdimm: fix phys_addr for nvdimm_clear_poison
  x86, dax, pmem: remove indirection around memcpy_from_pmem()
  block: remove block_device_operations ->direct_access()
  block, dax: convert bdev_dax_supported() to dax_direct_access()
  filesystem-dax: convert to dax_direct_access()
  Revert "block: use DAX for partition table reads"
  ext2, ext4, xfs: retrieve dax_device for iomap operations
  ...

arch/powerpc/platforms/Kconfig

@@ -284,6 +284,7 @@ config CPM2
 config AXON_RAM
 	tristate "Axon DDR2 memory device driver"
 	depends on PPC_IBM_CELL_BLADE && BLOCK
+	select DAX
 	default m
 	help
 	  It registers one block device per Axon's DDR2 memory bank found

arch/powerpc/sysdev/axonram.c

@@ -25,6 +25,7 @@
 
 #include <linux/bio.h>
 #include <linux/blkdev.h>
+#include <linux/dax.h>
 #include <linux/device.h>
 #include <linux/errno.h>
 #include <linux/fs.h>
@@ -62,6 +63,7 @@ static int azfs_major, azfs_minor;
 struct axon_ram_bank {
 	struct platform_device	*device;
 	struct gendisk		*disk;
+	struct dax_device	*dax_dev;
 	unsigned int		irq_id;
 	unsigned long		ph_addr;
 	unsigned long		io_addr;
@@ -137,25 +139,32 @@ axon_ram_make_request(struct request_queue *queue, struct bio *bio)
 	return BLK_QC_T_NONE;
 }
 
-/**
- * axon_ram_direct_access - direct_access() method for block device
- * @device, @sector, @data: see block_device_operations method
- */
+static const struct block_device_operations axon_ram_devops = {
+	.owner		= THIS_MODULE,
+};
+
 static long
-axon_ram_direct_access(struct block_device *device, sector_t sector,
-		       void **kaddr, pfn_t *pfn, long size)
+__axon_ram_direct_access(struct axon_ram_bank *bank, pgoff_t pgoff, long nr_pages,
+		       void **kaddr, pfn_t *pfn)
 {
-	struct axon_ram_bank *bank = device->bd_disk->private_data;
-	loff_t offset = (loff_t)sector << AXON_RAM_SECTOR_SHIFT;
+	resource_size_t offset = pgoff * PAGE_SIZE;
 
 	*kaddr = (void *) bank->io_addr + offset;
 	*pfn = phys_to_pfn_t(bank->ph_addr + offset, PFN_DEV);
-	return bank->size - offset;
+	return (bank->size - offset) / PAGE_SIZE;
 }
 
-static const struct block_device_operations axon_ram_devops = {
-	.owner		= THIS_MODULE,
-	.direct_access	= axon_ram_direct_access
+static long
+axon_ram_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
+		       void **kaddr, pfn_t *pfn)
+{
+	struct axon_ram_bank *bank = dax_get_private(dax_dev);
+
+	return __axon_ram_direct_access(bank, pgoff, nr_pages, kaddr, pfn);
+}
+
+static const struct dax_operations axon_ram_dax_ops = {
+	.direct_access = axon_ram_dax_direct_access,
 };
 
 /**
@@ -219,6 +228,7 @@ static int axon_ram_probe(struct platform_device *device)
 		goto failed;
 	}
 
+
 	bank->disk->major = azfs_major;
 	bank->disk->first_minor = azfs_minor;
 	bank->disk->fops = &axon_ram_devops;
@@ -227,6 +237,13 @@ static int axon_ram_probe(struct platform_device *device)
 	sprintf(bank->disk->disk_name, "%s%d",
 			AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
 
+	bank->dax_dev = alloc_dax(bank, bank->disk->disk_name,
+			&axon_ram_dax_ops);
+	if (!bank->dax_dev) {
+		rc = -ENOMEM;
+		goto failed;
+	}
+
 	bank->disk->queue = blk_alloc_queue(GFP_KERNEL);
 	if (bank->disk->queue == NULL) {
 		dev_err(&device->dev, "Cannot register disk queue\n");
@@ -278,6 +295,8 @@ failed:
 				del_gendisk(bank->disk);
 			put_disk(bank->disk);
 		}
+		kill_dax(bank->dax_dev);
+		put_dax(bank->dax_dev);
 		device->dev.platform_data = NULL;
 		if (bank->io_addr != 0)
 			iounmap((void __iomem *) bank->io_addr);
@@ -300,6 +319,8 @@ axon_ram_remove(struct platform_device *device)
 
 	device_remove_file(&device->dev, &dev_attr_ecc);
 	free_irq(bank->irq_id, device);
+	kill_dax(bank->dax_dev);
+	put_dax(bank->dax_dev);
 	del_gendisk(bank->disk);
 	put_disk(bank->disk);
 	iounmap((void __iomem *) bank->io_addr);