How to invalidate/disable cache

Hi all,
When I try to disable cache, I am not found any instruction can disable/enable cache, also there is no cache invalidate instruction.
Is the cache always on in freedom/rocket implement?
By the way, when generate verilog in rocket, there is “C” attribute, what’s that mean? is it means support cacheable or atomic? if it means cacheable, is it both for instruction and data?

Thank you!

Generated Address Map
0 - 1000 RWX debug-controller@0
3000 - 4000 RW C error-device@3000
10000 - 20000 R X rom@10000
2000000 - 2010000 RW clint@2000000
c000000 - 10000000 RW interrupt-controller@c000000
60000000 - 80000000 RWX mmio@60000000
80000000 - c0000000 RWXC memory@80000000

There are currently no cache control instructions defined but there has been much discussion about added some.

The most up to date proposal is here:!msg/isa-dev/Xa1y68PxjAU/MB2rLM1zAAAJ

You could also look back from there a little in the mailing list archive to find the earlier discussions.