Add an extension to the character device interface that allows character

device drivers to use arbitrary VM objects to satisfy individual mmap()
requests.
- A new d_mmap_single(cdev, &foff, objsize, &object, prot) callback is
  added to cdevsw.  This function is called for each mmap() request.
  If it returns ENODEV, then the mmap() request will fall back to using
  the device's device pager object and d_mmap().  Otherwise, the method
  can return a VM object to satisfy this entire mmap() request via
  *object.  It can also modify the starting offset into this object via
  *foff.  This allows device drivers to use the file offset as a cookie
  to identify specific VM objects.
- vm_mmap_vnode() has been changed to call vm_mmap_cdev() directly when
  mapping V_CHR vnodes.  This avoids duplicating all the cdev mmap
  handling code and simplifies some of vm_mmap_vnode().
- D_VERSION has been bumped to D_VERSION_02.  Older device drivers
  using D_VERSION_01 are still supported.

MFC after:	1 month

0 files changed, 0 insertions, 0 deletions