The largest possible order is (63-PAGE_SHIFT), given that our min chunk
size is PAGE_SIZE. With that we should only need at most 6 bits to
represent all possible orders, giving us back 4 bits for other potential
uses. Include a simple selftest to verify this.
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20210126103019.177622-1-matthew.auld@intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Simple buddy allocator. We want to allocate properly aligned
power-of-two blocks to promote usage of huge-pages for the GTT, so 64K,
2M and possibly even 1G. While we do support allocating stuff at a
specific offset, it is more intended for preallocating portions of the
address space, say for an initial framebuffer, for other uses drm_mm is
probably a much better fit. Anyway, hopefully this can all be thrown
away if we eventually move to having the core MM manage device memory.
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190809202926.14545-2-matthew.auld@intel.com
