Re: [PATCH v3 03/18] cxl: Define process problem state area at attach time only
From: Frederic Barrat <hidden>
Date: 2016-02-11 14:40:15
From: Frederic Barrat <hidden>
Date: 2016-02-11 14:40:15
Le 10/02/2016 07:32, Ian Munsie a écrit :
It might be a reasonable idea to make cxl_psa_map fail outright if it is called on a context that has not been attached yet like we do in the user api, but I trust kernel devs to get this right more than userspace so I'm not too worried :)
The net effect will be the same (we return a NULL pointer, which will need to be handled properly by the caller), but I like your suggestion of checking whether the context is attached first, which avoids calling ioremap() with null parameters. Pushing it further: if we don't allow mapping the psa before attaching, then I believe the call to cxl_afu_check_and_enable() is no longer useful, since the AFU will be enabled on the first attach() [ the very existence of the call to cxl_afu_check_and_enable() confirms my first impression: allowing to map the psa before attaching was deliberate ] Fred