No, ARM Didn't Open-Source Their Full Mali Linux Driver
A few links have been sent in to our news tip box with this page, which reads, "Open Source Mali-200/300/400/450 GPU Kernel Device Drivers." While the page mentions open-source drivers, it's only about the kernel portion of the driver and it's always been that way with ARM -- and most other ARM-based graphics vendors. The kernel portion is open, the user-space components are closed. Without an open user-space, having an open kernel driver is only of limited use, and will not be accepted into the upstream Linux kernel.