Re: [qemu-s390x] [PATCH v5 10/15] s390-bios: Support for running format-0/1 channel programs

[Thomas Huth]

On 13/03/2019 17.31, Jason J. Herne wrote:
> Introduce a library function for executing format-0 and format-1
> channel programs and waiting for their completion before continuing
> execution.
> 
> Add cu_type() to channel io library. This will be used to query control
> unit type which is used to determine if we are booting a virtio device or a
> real dasd device.
> 
> Signed-off-by: Jason J. Herne <address@hidden>
> Reviewed-by: Cornelia Huck <address@hidden>
> ---
[...]
> +/*
> + * Executes a channel program at a given subchannel. The request to run the
> + * channel program is sent to the subchannel, we then wait for the interrupt
> + * signaling completion of the I/O operation(s) performed by the channel
> + * program. Lastly we verify that the i/o operation completed without error 
> and
> + * that the interrupt we received was for the subchannel used to run the
> + * channel program.
> + *
> + * Note: This function assumes it is running in an environment where no other
> + * cpus are generating or receiving I/O interrupts. So either run it in a
> + * single-cpu environment or make sure all other cpus are not doing I/O and
> + * have I/O interrupts masked off. We also assume that only one device is
> + * active (generating i/o interrupts). 

checkpatch.pl (and my "git am") complain about a superfluous white space
in above line, so in case you respin, please remove it (otherwise this
could also be fixed when the patches are picked up).

Acked-by: Thomas Huth <address@hidden>