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| author | Michael Holzheu <holzheu@linux.vnet.ibm.com> | 2013-06-06 09:52:08 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2013-06-26 21:10:13 +0200 |
| commit | d475f942b1dd6a897dac3ad4ed98d6994b275378 (patch) | |
| tree | 43f599275ef7ac5350ea25f8f1eeb2690d6dc4e4 /drivers/s390/char/sclp.c | |
| parent | e9a8f32a98a6099b009ea7da4f299bb5427db126 (diff) | |
| download | linux-d475f942b1dd6a897dac3ad4ed98d6994b275378.tar.bz2 | |
s390/sclp: Add SCLP character device driver
Add a character misc device "sclp_ctl" that allows to run SCCBs
from user space using the SCLP_CTL_SCCB ioctl.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/char/sclp.c')
| -rw-r--r-- | drivers/s390/char/sclp.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c index a77febeead1f..97319d692b04 100644 --- a/drivers/s390/char/sclp.c +++ b/drivers/s390/char/sclp.c @@ -148,14 +148,19 @@ static int sclp_init(void); int sclp_service_call(sclp_cmdw_t command, void *sccb) { - int cc; + int cc = 4; /* Initialize for program check handling */ asm volatile( - " .insn rre,0xb2200000,%1,%2\n" /* servc %1,%2 */ - " ipm %0\n" - " srl %0,28" - : "=&d" (cc) : "d" (command), "a" (__pa(sccb)) + "0: .insn rre,0xb2200000,%1,%2\n" /* servc %1,%2 */ + "1: ipm %0\n" + " srl %0,28\n" + "2:\n" + EX_TABLE(0b, 2b) + EX_TABLE(1b, 2b) + : "+&d" (cc) : "d" (command), "a" (__pa(sccb)) : "cc", "memory"); + if (cc == 4) + return -EINVAL; if (cc == 3) return -EIO; if (cc == 2) |