• Ben Widawsky's avatar
    drm/i915: Create bind/unbind abstraction for VMAs · 6f65e29a
    Ben Widawsky authored
    To sum up what goes on here, we abstract the vma binding, similarly to
    the previous object binding. This helps for distinguishing legacy
    binding, versus modern binding. To keep the code churn as minimal as
    possible, I am leaving in insert_entries(). It serves as the per
    platform pte writing basically. bind_vma and insert_entries do share a
    lot of similarities, and I did have designs to combine the two, but as
    mentioned already... too much churn in an already massive patchset.
    
    What follows are the 3 commits which existed discretely in the original
    submissions. Upon rebasing on Broadwell support, it became clear that
    separation was not good, and only made for more error prone code. Below
    are the 3 commit messages with all their history.
    
    drm/i915: Add bind/unbind object functions to VMA
    drm/i915: Use the new vm [un]bind functions
    drm/i915: reduce vm->insert_entries() usage
    
    drm/i915: Add bind/unbind object functions to VMA
    
    As we plumb the code with more VM information, it has become more
    obvious that the easiest way to deal with bind and unbind is to simply
    put the function pointers in the vm, and let those choose the correct
    way to handle the page table updates. This change allows many places in
    the code to simply be vm->bind, and not have to worry about
    distinguishing PPGTT vs GGTT.
    
    Notice that this patch has no impact on functionality. I've decided to
    save the actual change until the next patch because I think it's easier
    to review that way. I'm happy to squash the two, or let Daniel do it on
    merge.
    
    v2:
    Make ggtt handle the quirky aliasing ppgtt
    Add flags to bind object to support above
    Don't ever call bind/unbind directly for PPGTT until we have real, full
    PPGTT (use NULLs to assert this)
    Make sure we rebind the ggtt if there already is a ggtt binding.  This
    happens on set cache levels.
    Use VMA for bind/unbind (Daniel, Ben)
    
    v3: Reorganize ggtt_vma_bind to be more concise and easier to read
    (Ville). Change logic in unbind to only unbind ggtt when there is a
    global mapping, and to remove a redundant check if the aliasing ppgtt
    exists.
    
    v4: Make the bind function a bit smarter about the cache levels to avoid
    unnecessary multiple remaps. "I accept it is a wart, I think unifying
    the pin_vma / bind_vma could be unified later" (Chris)
    Removed the git notes, and put version info here. (Daniel)
    
    v5: Update the comment to not suck (Chris)
    
    v6:
    Move bind/unbind to the VMA. It makes more sense in the VMA structure
    (always has, but I was previously lazy). With this change, it will allow
    us to keep a distinct insert_entries.
    Reviewed-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
    Signed-off-by: default avatarBen Widawsky <ben@bwidawsk.net>
    
    drm/i915: Use the new vm [un]bind functions
    
    Building on the last patch which created the new function pointers in
    the VM for bind/unbind, here we actually put those new function pointers
    to use.
    
    Split out as a separate patch to aid in review. I'm fine with squashing
    into the previous patch if people request it.
    
    v2: Updated to address the smart ggtt which can do aliasing as needed
    Make sure we bind to global gtt when mappable and fenceable. I thought
    we could get away without this initialy, but we cannot.
    
    v3: Make the global GTT binding explicitly use the ggtt VM for
    bind_vma(). While at it, use the new ggtt_vma helper (Chris)
    
    At this point the original mailing list thread diverges. ie.
    
    v4^:
    use target_obj instead of obj for gen6 relocate_entry
    vma->bind_vma() can be called safely during pin. So simply do that
    instead of the complicated conditionals.
    Don't restore PPGTT bound objects on resume path
    Bug fix in resume path for globally bound Bos
    Properly handle secure dispatch
    Rebased on vma bind/unbind conversion
    Signed-off-by: default avatarBen Widawsky <ben@bwidawsk.net>
    
    drm/i915: reduce vm->insert_entries() usage
    
    FKA: drm/i915: eliminate vm->insert_entries()
    
    With bind/unbind function pointers in place, we no longer need
    insert_entries. We could, and want, to remove clear_range, however it's
    not totally easy at this point. Since it's used in a couple of place
    still that don't only deal in objects: setup, ppgtt init, and restore
    gtt mappings.
    
    v2: Don't actually remove insert_entries, just limit its usage. It will
    be useful when we introduce gen8. It will always be called from the vma
    bind/unbind.
    
    Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
    Signed-off-by: default avatarBen Widawsky <ben@bwidawsk.net>
    Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
    6f65e29a
i915_drv.h 78.3 KB