Since 2020 Intel engineers have been working on Linear Address Masking (LAM) as a feature similar to Arm's Top Byte Ignore (TBI) for letting user-space store metadata within some bits of pointers without masking it out before use. This can be of use to virtual machines, profiling / sanitizers / tagging, and other applications. The Intel LAM kernel support has finally been merged with Linux 6.4...
As noted back in March, the plan with Linux 6.4 is to start removing old, unused and unmaintained PCMCIA drivers. As part of that process to begin dropping old PCMCIA/CardBus driver code from the kernel, all of the PCMCIA "char" drivers were on the chopping block. Linus Torvalds pulled in the char/misc changes this week for Linux 6.4 and indeed those drivers are now removed. Meanwhile this pull introduced the new AMD CDX subsystem...