diff options
| -rw-r--r-- | drivers/s390/cio/vfio_ccw_cp.c | 37 |
1 files changed, 36 insertions, 1 deletions
diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index ba08fe137c2e..488b76cd6fb9 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -283,6 +283,33 @@ static long copy_ccw_from_iova(struct channel_program *cp, #define ccw_is_chain(_ccw) ((_ccw)->flags & (CCW_FLAG_CC | CCW_FLAG_DC)) +/* + * is_cpa_within_range() + * + * @cpa: channel program address being questioned + * @head: address of the beginning of a CCW chain + * @len: number of CCWs within the chain + * + * Determine whether the address of a CCW (whether a new chain, + * or the target of a TIC) falls within a range (including the end points). + * + * Returns 1 if yes, 0 if no. + */ +static inline int is_cpa_within_range(u32 cpa, u32 head, int len) +{ + u32 tail = head + (len - 1) * sizeof(struct ccw1); + + return (head <= cpa && cpa <= tail); +} + +static inline int is_tic_within_range(struct ccw1 *ccw, u32 head, int len) +{ + if (!ccw_is_tic(ccw)) + return 0; + + return is_cpa_within_range(ccw->cda, head, len); +} + static struct ccwchain *ccwchain_alloc(struct channel_program *cp, int len) { struct ccwchain *chain; @@ -392,7 +419,15 @@ static int ccwchain_calc_length(u64 iova, struct channel_program *cp) return -EOPNOTSUPP; } - if (!ccw_is_chain(ccw)) + /* + * We want to keep counting if the current CCW has the + * command-chaining flag enabled, or if it is a TIC CCW + * that loops back into the current chain. The latter + * is used for device orientation, where the CCW PRIOR to + * the TIC can either jump to the TIC or a CCW immediately + * after the TIC, depending on the results of its operation. + */ + if (!ccw_is_chain(ccw) && !is_tic_within_range(ccw, iova, cnt)) break; ccw++; |