I appreciate you digging up the relevant text from the manual, but I don't think you should accuse Samsung of wrongdoing based on such far fetched assumptions.
That document does not explicitly forbids this. In addition, take a look at their sample code which indeed reads some cache configuration registers during each call. The same code is found verbatim in the linux kernel, if you now don't trust the ARM engineers :)
I don't think considering how to actually implement the basic operation without a terrible performance penalty is a "far fetched assumption".
> That document does not explicitly forbids this.
Yet it makes it clear software can be written to assume it doesn't happen, which is the same thing.
> In addition, take a look at their sample code which indeed reads some cache configuration registers during each call.
This doesn't prevent the problem at all, it just reduces the window for things to go wrong.
> The same code is found verbatim in the linux kernel, if you now don't trust the ARM engineers :)
I trust the ARM engineers. As I already said, their code is right, Samsung got it wrong. Note that the libgcc code that breaks was ALSO written by ARM.
That document does not explicitly forbids this. In addition, take a look at their sample code which indeed reads some cache configuration registers during each call. The same code is found verbatim in the linux kernel, if you now don't trust the ARM engineers :)