Messages in this thread | | | Subject | Re: [patches] Re: [PATCH 2/7] RISC-V: arch/riscv Makefile and Kconfigs | From | Benjamin Herrenschmidt <> | Date | Wed, 24 May 2017 07:07:50 +1000 |
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On Mon, 2017-05-22 at 22:16 -0700, Olof Johansson wrote: > The same is true for some other drivers. Actually, I wonder if it > might be just as easy to implement a sbi backend for hvc -- see > hvc_udbg.c for an example where, on power, you have a simple get/put > char hypervisor call in a very similar manner.
Rather look at hvc_opal. This is the console driver we use on native POWER servers with the OPAL firmware, and it calls into a firmware in a very similar way.
The driver lives in drivers/tty/hvc. It does call some "helpers" in the arch code that wrap the actual FW calls.
> Either way (keeping discrete sbi driver or implementing hvc backend), > moving to drivers/tty is the right thing here -- we've worked hard on > ARM to get rid of random drivers under arch/ and it'd be nice to not > see new ones intoduced here.
Yup. The reason mostly is that if the tty maintainer needs to do a subsystem-wide change, he can address all drivers in drivers/tty and doesn't have to look for others elsewhere in the tree. This is the same for all subsystems.
Cheers, Ben.
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