Merge tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dan Williams:
 "This update has successfully completed a 0day-kbuild run and has
  appeared in a linux-next release.  The changes outside of the typical
  drivers/nvdimm/ and drivers/acpi/nfit.[ch] paths are related to the
  removal of IORESOURCE_CACHEABLE, the introduction of memremap(), and
  the introduction of ZONE_DEVICE + devm_memremap_pages().

  Summary:

   - Introduce ZONE_DEVICE and devm_memremap_pages() as a generic
     mechanism for adding device-driver-discovered memory regions to the
     kernel's direct map.

     This facility is used by the pmem driver to enable pfn_to_page()
     operations on the page frames returned by DAX ('direct_access' in
     'struct block_device_operations').

     For now, the 'memmap' allocation for these "device" pages comes
     from "System RAM".  Support for allocating the memmap from device
     memory will arrive in a later kernel.

   - Introduce memremap() to replace usages of ioremap_cache() and
     ioremap_wt().  memremap() drops the __iomem annotation for these
     mappings to memory that do not have i/o side effects.  The
     replacement of ioremap_cache() with memremap() is limited to the
     pmem driver to ease merging the api change in v4.3.

     Completion of the conversion is targeted for v4.4.

   - Similar to the usage of memcpy_to_pmem() + wmb_pmem() in the pmem
     driver, update the VFS DAX implementation and PMEM api to provide
     persistence guarantees for kernel operations on a DAX mapping.

   - Convert the ACPI NFIT 'BLK' driver to map the block apertures as
     cacheable to improve performance.

   - Miscellaneous updates and fixes to libnvdimm including support for
     issuing "address range scrub" commands, clarifying the optimal
     'sector size' of pmem devices, a clarification of the usage of the
     ACPI '_STA' (status) property for DIMM devices, and other minor
     fixes"

* tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (34 commits)
  libnvdimm, pmem: direct map legacy pmem by default
  libnvdimm, pmem: 'struct page' for pmem
  libnvdimm, pfn: 'struct page' provider infrastructure
  x86, pmem: clarify that ARCH_HAS_PMEM_API implies PMEM mapped WB
  add devm_memremap_pages
  mm: ZONE_DEVICE for "device memory"
  mm: move __phys_to_pfn and __pfn_to_phys to asm/generic/memory_model.h
  dax: drop size parameter to ->direct_access()
  nd_blk: change aperture mapping from WC to WB
  nvdimm: change to use generic kvfree()
  pmem, dax: have direct_access use __pmem annotation
  dax: update I/O path to do proper PMEM flushing
  pmem: add copy_from_iter_pmem() and clear_pmem()
  pmem, x86: clean up conditional pmem includes
  pmem: remove layer when calling arch_has_wmb_pmem()
  pmem, x86: move x86 PMEM API to new pmem.h header
  libnvdimm, e820: make CONFIG_X86_PMEM_LEGACY a tristate option
  pmem: switch to devm_ allocations
  devres: add devm_memremap
  libnvdimm, btt: write and validate parent_uuid
  ...

1 files changed, 13 insertions, 37 deletions

diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
index 341202ed32b4..254239746020 100644
--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c
@@ -583,33 +583,6 @@ static void free_arenas(struct btt *btt)
 }
 
 /*
- * This function checks if the metadata layout is valid and error free
- */
-static int arena_is_valid(struct arena_info *arena, struct btt_sb *super,
-				u8 *uuid, u32 lbasize)
-{
-	u64 checksum;
-
-	if (memcmp(super->uuid, uuid, 16))
-		return 0;
-
-	checksum = le64_to_cpu(super->checksum);
-	super->checksum = 0;
-	if (checksum != nd_btt_sb_checksum(super))
-		return 0;
-	super->checksum = cpu_to_le64(checksum);
-
-	if (lbasize != le32_to_cpu(super->external_lbasize))
-		return 0;
-
-	/* TODO: figure out action for this */
-	if ((le32_to_cpu(super->flags) & IB_FLAG_ERROR_MASK) != 0)
-		dev_info(to_dev(arena), "Found arena with an error flag\n");
-
-	return 1;
-}
-
-/*
  * This function reads an existing valid btt superblock and
  * populates the corresponding arena_info struct
  */
@@ -632,8 +605,9 @@ static void parse_arena_meta(struct arena_info *arena, struct btt_sb *super,
 	arena->logoff = arena_off + le64_to_cpu(super->logoff);
 	arena->info2off = arena_off + le64_to_cpu(super->info2off);
 
-	arena->size = (super->nextoff > 0) ? (le64_to_cpu(super->nextoff)) :
-			(arena->info2off - arena->infooff + BTT_PG_SIZE);
+	arena->size = (le64_to_cpu(super->nextoff) > 0)
+		? (le64_to_cpu(super->nextoff))
+		: (arena->info2off - arena->infooff + BTT_PG_SIZE);
 
 	arena->flags = le32_to_cpu(super->flags);
 }
@@ -665,8 +639,7 @@ static int discover_arenas(struct btt *btt)
 		if (ret)
 			goto out;
 
-		if (!arena_is_valid(arena, super, btt->nd_btt->uuid,
-				btt->lbasize)) {
+		if (!nd_btt_arena_is_valid(btt->nd_btt, super)) {
 			if (remaining == btt->rawsize) {
 				btt->init_state = INIT_NOTFOUND;
 				dev_info(to_dev(arena), "No existing arenas\n");
@@ -755,10 +728,13 @@ static int create_arenas(struct btt *btt)
  * It is only called for an uninitialized arena when a write
  * to that arena occurs for the first time.
  */
-static int btt_arena_write_layout(struct arena_info *arena, u8 *uuid)
+static int btt_arena_write_layout(struct arena_info *arena)
 {
 	int ret;
+	u64 sum;
 	struct btt_sb *super;
+	struct nd_btt *nd_btt = arena->nd_btt;
+	const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
 
 	ret = btt_map_init(arena);
 	if (ret)
@@ -773,7 +749,8 @@ static int btt_arena_write_layout(struct arena_info *arena, u8 *uuid)
 		return -ENOMEM;
 
 	strncpy(super->signature, BTT_SIG, BTT_SIG_LEN);
-	memcpy(super->uuid, uuid, 16);
+	memcpy(super->uuid, nd_btt->uuid, 16);
+	memcpy(super->parent_uuid, parent_uuid, 16);
 	super->flags = cpu_to_le32(arena->flags);
 	super->version_major = cpu_to_le16(arena->version_major);
 	super->version_minor = cpu_to_le16(arena->version_minor);
@@ -794,7 +771,8 @@ static int btt_arena_write_layout(struct arena_info *arena, u8 *uuid)
 	super->info2off = cpu_to_le64(arena->info2off - arena->infooff);
 
 	super->flags = 0;
-	super->checksum = cpu_to_le64(nd_btt_sb_checksum(super));
+	sum = nd_sb_checksum((struct nd_gen_sb *) super);
+	super->checksum = cpu_to_le64(sum);
 
 	ret = btt_info_write(arena, super);
 
@@ -813,7 +791,7 @@ static int btt_meta_init(struct btt *btt)
 
 	mutex_lock(&btt->init_lock);
 	list_for_each_entry(arena, &btt->arena_list, list) {
-		ret = btt_arena_write_layout(arena, btt->nd_btt->uuid);
+		ret = btt_arena_write_layout(arena);
 		if (ret)
 			goto unlock;
 
@@ -1447,8 +1425,6 @@ static int __init nd_btt_init(void)
 {
 	int rc;
 
-	BUILD_BUG_ON(sizeof(struct btt_sb) != SZ_4K);
-
 	btt_major = register_blkdev(0, "btt");
 	if (btt_major < 0)
 		return btt_major;