Arch-handbook, scsi-general, typos in XPT_CALC_GEOMETRY?

[Alexey Illarionov]

http://www.freebsd.org/doc/en_US.ISO8859-1/books/arch-handbook/scsi-general.html

Quote:

XPT_CALC_GEOMETRY - calculate logical (BIOS) geometry of the disk
	The arguments are transferred in the instance “struct ccb_calc_geometry ccg” of the union ccb:
    * block_size - input, block (A.K.A sector) size in bytes
    * volume_size - input, volume size in bytes (???)
    * cylinders - output, logical cylinders
    * heads - output, logical heads
    * secs_per_track - output, logical sectors per track

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The typical calculation example taken from the aic7xxx driver is:
    struct    ccb_calc_geometry *ccg;
    u_int32_t size_mb;
    u_int32_t secs_per_cylinder;
    int   extended;
    ccg = &ccb->ccg;
    size_mb = ccg->volume_size
        / ((1024L * 1024L) / ccg->block_size);
    extended = check_cards_EEPROM_for_extended_geometry(softc);

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The volume_size argument whether really it is the size of volume in bytes or in sectors?

If it in bytes, how it seems to me, the variable size_mb is calculated not correctly 
( should be size_mb = ccg->volume_size / (1024L * 1024L) )

If it in sectors it calculated not correctly too.
It can cause division by zero, if ccg->block_size will be more than one mbyte ( > 1024L * 1024L)
I understand, that it is almost impossible, but I get this in result of different error (usb/73307).
If I remember arithmetics,
ccg->volume_size / ((1024L * 1024L) / ccg->block_size) == 
ccg->volume_size * ((ccg->block_size / (1024L * 1024L)) ==
(ccg->volume_size * ccg->block_size) / (1024L * 1024L)
Such formula is more intuitively clear and will not cause division by zero. It is only necessary 
for (ccg->volume_size * ccg->block_size) to use u_int64_t or manually check for overflows

Besides aic7xxx driver now have this code:
#if __FreeBSD_version >= 500000
        cam_calc_geometry(ccg, extended);
#else
...

I think, it can be added to this part of handbook. What do you think about this?