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    SubjectRe: aoe fails on sparc64
    Date
    "David S. Miller" <davem@davemloft.net> writes:

    > From: Ed L Cashin <ecashin@coraid.com>
    ...
    >> OK. 67553994410557440 is 61440 byte swapped in 64 bits, and 30MB is
    >> 61440 sectors, so this should be a simple byte order fix.
    >
    > More strangely, the upper and lower 32-bit words are swapped.
    > The bytes within each 32-bit word are swapped correctly.
    >
    > So the calculation maybe should be something like:
    >
    > __le32 *p = (__le32 *) &id[100 << 1];
    > u32 high32 = le32_to_cpup(p);
    > u32 low32 = le32_to_cpup(p + 1);
    >
    > ssize = (((u64)high32 << 32) | (u64) low32);
    >
    > But that doesn't make any sense, and even ide_fix_driveid() in
    > drivers/ide/ide-iops.c does a le64_to_cpu() for this value:
    >
    > id->lba_capacity_2 = __le64_to_cpu(id->lba_capacity_2);
    >
    > I wonder if this is some artifact of how AOE devices encode
    > this field when sending it to the client.

    Well, an EtherDrive blade just copies the ATA identify response data
    into a network packet without looking at it. The vblade, though, has
    to set the lba_capacity and lba_capacity_2 fields itself.

    The aoe driver looks OK, but it turns out there's a byte swapping bug
    in the vblade that could be related if he's running the vblade on a
    big endian host (even though he said it was an x86 host), but I
    haven't heard back from the original poster yet.

    The vblade bug was the omission of swapping the bytes in each short.
    The fix below shows what I mean:

    diff -urNp a-exp/ata.c b-exp/ata.c
    --- a-exp/ata.c 2005-09-01 10:19:11.000000000 -0400
    +++ b-exp/ata.c 2005-09-01 10:19:12.000000000 -0400
    @@ -55,24 +55,29 @@ setfld(ushort *a, int idx, int len, char
    }

    static void
    -setlba28(ushort *p, vlong lba)
    +setlba28(ushort *ident, vlong lba)
    {
    - p += 60;
    - *p++ = lba & 0xffff;
    - *p = lba >> 16 & 0x0fffffff;
    + uchar *cp;
    +
    + cp = (uchar *) &ident[60];
    + *cp++ = lba;
    + *cp++ = lba >>= 8;
    + *cp++ = lba >>= 8;
    + *cp++ = (lba >>= 8) & 0xf;
    }

    static void
    -setlba48(ushort *p, vlong lba)
    +setlba48(ushort *ident, vlong lba)
    {
    - p += 100;
    - *p++ = lba;
    - lba >>= 16;
    - *p++ = lba;
    - lba >>= 16;
    - *p++ = lba;
    - lba >>= 16;
    - *p = lba;
    + uchar *cp;
    +
    + cp = (uchar *) &ident[100];
    + *cp++ = lba;
    + *cp++ = lba >>= 8;
    + *cp++ = lba >>= 8;
    + *cp++ = lba >>= 8;
    + *cp++ = lba >>= 8;
    + *cp++ = lba >>= 8;
    }

    void

    --
    Ed L Cashin <ecashin@coraid.com>

    -
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