How to test L1/L2 cache?

Thank you, Sujun. 

But what I want to do is to verify the L1/L2 cache like to verify any other memory parts. In other words, I hope I can write some pattern, say all '0' or 'F' to the cache and read back and compare to see if there is any difference (failure).

So far, I can be sure that we can do this in EL3 for L1. But I didn't see any post for L2 cache.

Thank you, Sujun. 

But what I want to do is to verify the L1/L2 cache like to verify any other memory parts. In other words, I hope I can write some pattern, say all '0' or 'F' to the cache and read back and compare to see if there is any difference (failure).

So far, I can be sure that we can do this in EL3 for L1. But I didn't see any post for L2 cache.