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

commit 45a0dac0451136fa7ae34a6fea53ef6a136287ce upstream.

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/nvdimm/pfn.h b/drivers/nvdimm/pfn.h
index 8e343a3ca873012a7124c46564f9bcc4833c7a67..9d2704c83fa74ef1e7905b4b8d38c359ebdda6ac 100644 (file)
--- a/drivers/nvdimm/pfn.h
+++ b/drivers/nvdimm/pfn.h
@@ -33,7 +33,9 @@ struct nd_pfn_sb {
        /* minor-version-1 additions for section alignment */
        __le32 start_pad;
        __le32 end_trunc;
-       u8 padding[4004];
+       /* minor-version-2 record the base alignment of the mapping */
+       __le32 align;
+       u8 padding[4000];
        __le64 checksum;
 };
 

diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index e071e214febadae71d2d369319b76cd5b6b1a851..58bf68c9c414a4dc88a9e18678c54a1fb3e6e9a7 100644 (file)
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -360,6 +360,9 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
                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:
        case PFN_MODE_PMEM:
@@ -399,7 +402,7 @@ 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);

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 92f536596b24295f0b19aea551844eecb95f7df6..58ad81dcd1a5c8e4a2dca2271f9ce7ef8ae2a95c 100644 (file)
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -426,9 +426,10 @@ 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);