CVE-2024-44949

In the Linux kernel, the following vulnerability has been resolved:

parisc: fix a possible DMA corruption

ARCHDMAMINALIGN was defined as 16 - this is too small - it may be possible that two unrelated 16-byte allocations share a cache line. If one of these allocations is written using DMA and the other is written using cached write, the value that was written with DMA may be corrupted.

This commit changes ARCHDMAMINALIGN to be 128 on PA20 and 32 on PA1.1 - that's the largest possible cache line size.

As different parisc microarchitectures have different cache line size, we define archslabminalign(), cachelinesize() and dmagetcache_alignment() so that the kernel may tune slab cache parameters dynamically, based on the detected cache line size.