On Tue, 19 Sep 2017 20:27:45 +0200
Halil Pasic <pa...@linux.vnet.ibm.com> wrote:
> Let's add indirect data addressing support for our virtual channel
> subsystem. This implementation does not bother with any kind of
> prefetching. We simply step through the IDAL on demand.
>
> Signed-off-by: Halil Pasic <pa...@linux.vnet.ibm.com>
> Signed-off-by: Cornelia Huck <coh...@redhat.com>
My s-o-b is a bit preliminary ;)
> ---
> hw/s390x/css.c | 117
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 116 insertions(+), 1 deletion(-)
>
> diff --git a/hw/s390x/css.c b/hw/s390x/css.c
> index 2d37a9ddde..a3ce6d89b6 100644
> --- a/hw/s390x/css.c
> +++ b/hw/s390x/css.c
> @@ -827,6 +827,121 @@ incr:
> return 0;
> }
>
> +/* returns values between 1 and bsz, where bsz is a power of 2 */
> +static inline uint16_t ida_continuous_left(hwaddr cda, uint64_t bsz)
> +{
> + return bsz - (cda & (bsz - 1));
> +}
> +
> +static inline uint64_t ccw_ida_block_size(uint8_t flags)
> +{
> + if ((flags & CDS_F_C64) && !(flags & CDS_F_I2K)) {
> + return 1ULL << 12;
> + }
> + return 1ULL << 11;
> +}
> +
> +static inline int ida_read_next_idaw(CcwDataStream *cds, bool ccw_fmt1,
> + bool idaw_fmt_2)
> +{
> + union {uint64_t fmt2; uint32_t fmt1; } idaw;
> + int ret;
> + hwaddr idaw_addr;
> +
> + if (idaw_fmt_2) {
> + idaw_addr = cds->cda_orig + sizeof(idaw.fmt2) * cds->at_idaw;
> + if (idaw_addr & 0x07 && cds_ccw_addrs_ok(idaw_addr, 0, ccw_fmt1)) {
So, what is supposed to happen if the idaw_addr is not aligned
correctly _and_ is violating the limits?
> + return -EINVAL; /* channel program check */
> + }
> + ret = address_space_rw(&address_space_memory, idaw_addr,
> + MEMTXATTRS_UNSPECIFIED, (void *) &idaw.fmt2,
> + sizeof(idaw.fmt2), false);
> + cds->cda = be64_to_cpu(idaw.fmt2);
> + } else {
> + idaw_addr = cds->cda_orig + sizeof(idaw.fmt1) * cds->at_idaw;
> + if (idaw_addr & 0x03 && cds_ccw_addrs_ok(idaw_addr, 0, ccw_fmt1)) {
> + return -EINVAL; /* channel program check */
> + }
> + ret = address_space_rw(&address_space_memory, idaw_addr,
> + MEMTXATTRS_UNSPECIFIED, (void *) &idaw.fmt1,
> + sizeof(idaw.fmt1), false);
> + cds->cda = be64_to_cpu(idaw.fmt1);
> + }
> + ++(cds->at_idaw);
> + if (ret != MEMTX_OK) {
> + /* assume inaccessible address */
> + return -EINVAL; /* channel program check */
> +
> + }
> + return 0;
> +}
