On Wed, 20 Sep 2017 19:23:13 +0200
Halil Pasic <pa...@linux.vnet.ibm.com> wrote:
> Let us convert the 3270 code so it uses the recently introduced
> CcwDataStream abstraction instead of blindly assuming direct data access.
>
> This patch does not change behavior beyond introducing IDA support: for
> direct data access CCWs everything stays as-is. (If there are bugs, they
> are also preserved).
>
> Signed-off-by: Halil Pasic <pa...@linux.vnet.ibm.com>
> Acked-by: Christian Borntraeger <borntrae...@de.ibm.com>
> Reviewed-by: Dong Jia Shi <bjsdj...@linux.vnet.ibm.com>
> ---
> hw/char/terminal3270.c | 18 +++++++++++-------
> hw/s390x/3270-ccw.c | 4 ++--
> include/hw/s390x/3270-ccw.h | 5 ++---
> 3 files changed, 15 insertions(+), 12 deletions(-)
>
> diff --git a/hw/char/terminal3270.c b/hw/char/terminal3270.c
> index 28f599111d..c976a63cc2 100644
> --- a/hw/char/terminal3270.c
> +++ b/hw/char/terminal3270.c
> @@ -182,14 +182,18 @@ static void terminal_init(EmulatedCcw3270Device *dev,
> Error **errp)
> terminal_read, chr_event, NULL, t, NULL, true);
> }
>
> -static int read_payload_3270(EmulatedCcw3270Device *dev, uint32_t cda,
> - uint16_t count)
> +static inline CcwDataStream *get_cds(Terminal3270 *t)
> +{
> + return &(CCW_DEVICE(&t->cdev)->sch->cds);
> +}
> +
> +static int read_payload_3270(EmulatedCcw3270Device *dev)
> {
> Terminal3270 *t = TERMINAL_3270(dev);
> int len;
>
> - len = MIN(count, t->in_len);
> - cpu_physical_memory_write(cda, t->inv, len);
> + len = MIN(ccw_dstream_avail(get_cds(t)), t->in_len);
> + ccw_dstream_write_buf(get_cds(t), t->inv, len);
CCW_DEVICE() as called by get_cds() goes through qom, which implies a
bit of overhead. Not sure if it makes sense to cache it in this
function so you don't go through it multiple times. (Dito for the other
callback.)
> t->in_len -= len;
>
> return len;
Looks good.
