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| author | Eric Farman <farman@linux.ibm.com> | 2019-05-16 18:14:03 +0200 |
|---|---|---|
| committer | Cornelia Huck <cohuck@redhat.com> | 2019-06-03 12:02:55 +0200 |
| commit | 9b6e57e5a51696171de990b3c41bd53d4b8ab8ac (patch) | |
| tree | 1c8eb0b1fe09b72cf400a17ec5b8419258ef45a8 /drivers | |
| parent | s390/cio: Allow zero-length CCWs in vfio-ccw (diff) | |
| download | linux-9b6e57e5a51696171de990b3c41bd53d4b8ab8ac.tar.xz linux-9b6e57e5a51696171de990b3c41bd53d4b8ab8ac.zip | |
s390/cio: Remove vfio-ccw checks of command codes
If the CCW being processed is a No-Operation, then by definition no
data is being transferred. Let's fold those checks into the normal
CCW processors, rather than skipping out early.
Likewise, if the CCW being processed is a "test" (a category defined
here as an opcode that contains zero in the lowest four bits) then no
special processing is necessary as far as vfio-ccw is concerned.
These command codes have not been valid since the S/370 days, meaning
they are invalid in the same way as one that ends in an eight [1] or
an otherwise valid command code that is undefined for the device type
in question. Considering that, let's just process "test" CCWs like
any other CCW, and send everything to the hardware.
[1] POPS states that a x08 is a TIC CCW, and that having any high-order
bits enabled is invalid for format-1 CCWs. For format-0 CCWs, the
high-order bits are ignored.
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20190516161403.79053-4-farman@linux.ibm.com>
Acked-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/s390/cio/vfio_ccw_cp.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index c77c9b4cd2a8..f73cfcfdd032 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -295,8 +295,6 @@ static long copy_ccw_from_iova(struct channel_program *cp, #define ccw_is_read_backward(_ccw) (((_ccw)->cmd_code & 0x0F) == 0x0C) #define ccw_is_sense(_ccw) (((_ccw)->cmd_code & 0x0F) == CCW_CMD_BASIC_SENSE) -#define ccw_is_test(_ccw) (((_ccw)->cmd_code & 0x0F) == 0) - #define ccw_is_noop(_ccw) ((_ccw)->cmd_code == CCW_CMD_NOOP) #define ccw_is_tic(_ccw) ((_ccw)->cmd_code == CCW_CMD_TIC) @@ -320,6 +318,10 @@ static inline int ccw_does_data_transfer(struct ccw1 *ccw) if (ccw->count == 0) return 0; + /* If the command is a NOP, then no data will be transferred */ + if (ccw_is_noop(ccw)) + return 0; + /* If the skip flag is off, then data will be transferred */ if (!ccw_is_skip(ccw)) return 1; @@ -404,7 +406,7 @@ static void ccwchain_cda_free(struct ccwchain *chain, int idx) { struct ccw1 *ccw = chain->ch_ccw + idx; - if (ccw_is_test(ccw) || ccw_is_noop(ccw) || ccw_is_tic(ccw)) + if (ccw_is_tic(ccw)) return; kfree((void *)(u64)ccw->cda); @@ -730,9 +732,6 @@ static int ccwchain_fetch_one(struct ccwchain *chain, { struct ccw1 *ccw = chain->ch_ccw + idx; - if (ccw_is_test(ccw) || ccw_is_noop(ccw)) - return 0; - if (ccw_is_tic(ccw)) return ccwchain_fetch_tic(chain, idx, cp); |