libnvdimm, dax: record the specified alignment of a dax-device instance

Orabug: 22913653

We want to use the alignment as the allocation and mapping unit.
Previously this information was only useful for establishing the data
offset, but now it is important to remember the granularity for the
later use.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dan Duval <dan.duval@oracle.com>
(cherry picked from commit 45a0dac0451136fa7ae34a6fea53ef6a136287ce)

Conflicts:

	drivers/nvdimm/pfn.h
	drivers/nvdimm/pfn_devs.c

diff --git a/drivers/nvdimm/pfn.h b/drivers/nvdimm/pfn.h
index cc243754acef00df27dbc5d11d36d5c9a8af7d6f..a9077cf35d019990b54dcf763ba619a70669b85c 100644 (file)
--- a/drivers/nvdimm/pfn.h
+++ b/drivers/nvdimm/pfn.h
@@ -29,7 +29,12 @@ struct nd_pfn_sb {
        __le64 dataoff;
        __le64 npfns;
        __le32 mode;
-       u8 padding[4012];
+       /* minor-version-1 additions for section alignment */
+       __le32 start_pad;
+       __le32 end_trunc;
+       /* minor-version-2 record the base alignment of the mapping */
+       __le32 align;
+       u8 padding[4000];
        __le64 checksum;
 };
 #endif /* __NVDIMM_PFN_H */

diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 5f51d679c37f962ef4aac05eca9007ab2370e473..b28728f3cb112e1c8ddc954c92040e4fe8b4903e 100644 (file)
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -387,6 +387,14 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
        if (memcmp(pfn_sb->parent_uuid, parent_uuid, 16) != 0)
                return -ENODEV;
 
+       if (__le16_to_cpu(pfn_sb->version_minor) < 1) {
+               pfn_sb->start_pad = 0;
+               pfn_sb->end_trunc = 0;
+       }
+
+       if (__le16_to_cpu(pfn_sb->version_minor) < 2)
+               pfn_sb->align = 0;
+
        switch (le32_to_cpu(pfn_sb->mode)) {
        case PFN_MODE_RAM:
                break;
@@ -428,7 +436,7 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
                return -EBUSY;
        }
 
-       nd_pfn->align = 1UL << ilog2(offset);
+       nd_pfn->align = le32_to_cpu(pfn_sb->align);
        if (!is_power_of_2(offset) || offset < PAGE_SIZE) {
                dev_err(&nd_pfn->dev, "bad offset: %#llx dax disabled\n",
                                offset);
@@ -627,9 +635,10 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
        memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
        memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16);
        pfn_sb->version_major = cpu_to_le16(1);
-       pfn_sb->version_minor = cpu_to_le16(1);
+       pfn_sb->version_minor = cpu_to_le16(2);
        pfn_sb->start_pad = cpu_to_le32(start_pad);
        pfn_sb->end_trunc = cpu_to_le32(end_trunc);
+       pfn_sb->align = cpu_to_le32(nd_pfn->align);
        checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
        pfn_sb->checksum = cpu_to_le64(checksum);