diff options
| author | Eric Farman <farman@linux.ibm.com> | 2020-12-02 19:37:24 +0100 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2023-01-09 14:34:08 +0100 |
| commit | 6a6dc14ac84733cf5864a7cf9f5b3e43f6a79be8 (patch) | |
| tree | 7a9ea8fb6919d9d0414be728428ea4313dfa45c0 /drivers/s390/cio | |
| parent | 667e5dbabf2bb790640525cff7d563cf88eb3e61 (diff) | |
vfio/ccw: calculate number of IDAWs regardless of format
The idal_nr_words() routine works well for 4K IDAWs, but lost its
ability to handle the old 2K formats with the removal of 31-bit
builds in commit 5a79859ae0f3 ("s390: remove 31 bit support").
Since there's nothing preventing a guest from generating this IDAW
format, let's re-introduce the math for them and use both when
calculating the number of IDAWs based on the bits specified in
the ORB.
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'drivers/s390/cio')
| -rw-r--r-- | drivers/s390/cio/vfio_ccw_cp.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index fbb46bec3174..6a2c6ee83807 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -502,6 +502,13 @@ static int ccwchain_fetch_tic(struct ccw1 *ccw, * * @ccw: The Channel Command Word being translated * @cp: Channel Program being processed + * + * The ORB is examined, since it specifies what IDAWs could actually be + * used by any CCW in the channel program, regardless of whether or not + * the CCW actually does. An ORB that does not specify Format-2-IDAW + * Control could still contain a CCW with an IDAL, which would be + * Format-1 and thus only move 2K with each IDAW. Thus all CCWs within + * the channel program must follow the same size requirements. */ static int ccw_count_idaws(struct ccw1 *ccw, struct channel_program *cp) @@ -533,6 +540,15 @@ static int ccw_count_idaws(struct ccw1 *ccw, iova = ccw->cda; } + /* Format-1 IDAWs operate on 2K each */ + if (!cp->orb.cmd.c64) + return idal_2k_nr_words((void *)iova, bytes); + + /* Using the 2K variant of Format-2 IDAWs? */ + if (cp->orb.cmd.i2k) + return idal_2k_nr_words((void *)iova, bytes); + + /* The 'usual' case is 4K Format-2 IDAWs */ return idal_nr_words((void *)iova, bytes); } |