Change Details

For sub-page sizes, we end up not pre-allocating enough for a single mapping because the math works out to 0 additional pages required. This is problematic if the only consumers are using BUS_DMA_NOWAIT and only using the not-actually-preallocated buffer.

For any size that isn't page-aligned, we end up not pre-allocating enough for a single mapping because we truncate the size instead of rounding up to make sure the last bit is accounted for, leaving us one page shy of what we need.

For sub-any size that isn't page sizes-aligned, we end up not pre-allocating enough for a single mapping because the math works outwe truncate the size instead of rounding up to 0 additional pages required.make sure the last bit is accounted for, This is problematic if the only consumers are using BUS_DMA_NOWAIT and only using the not-actually-preallocated bufferleaving us one page shy of what we need.