linux/drivers/s390/cio/ioasm.c
Vineeth Vijayan a4f17cc726 s390/cio: add CRW inject functionality
This patch introduces the mechanism to inject artificial events to the
CIO layer.

One of the main-event type which triggers the CommonIO operations are
Channel Report events. When a malfunction or other condition affecting
channel-subsystem operation is recognized, a Channel Report Word
(consisting of one or more CRWs) describing the condition is made
pending for retrieval and analysis by the program. The CRW contains
information concerning the identity and state of a facility following
the detection of the malfunction or other condition.

The patch introduces two debugfs interfaces which can be used to inject
'artificial' events from the userspace. It is intended to provide an easy
means to increase the test coverage for CIO code. And this functionality
can be enabled via a new configuration option CONFIG_CIO_INJECT.

The newly introduces debugfs interfaces can be used as mentioned below
to generate different fake-events. To use the crw_inject, first we should
enable it by using enable_inject interface.
i.e

echo 1 > /sys/kernel/debug/s390/cio/enable_inject

After the first step, user can simulate CRW as follows:

echo <solicited> <overflow> <chaining> <rsc> <ancillary> <erc> <rsid> \
                               > /sys/kernel/debug/s390/cio/crw_inject

Example:
A permanent error ERC on CHPID 0x60 would look like this:

  echo 0 0 0 4 0 6 0x60 > /sys/kernel/debug/s390/cio/crw_inject

and an initialized ERC on the same CHPID:

  echo 0 0 0 4 0 2 0x60 > /sys/kernel/debug/s390/cio/crw_inject

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-03-22 11:36:04 +01:00

299 lines
4.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Channel subsystem I/O instructions.
*/
#include <linux/export.h>
#include <asm/chpid.h>
#include <asm/schid.h>
#include <asm/crw.h>
#include "ioasm.h"
#include "orb.h"
#include "cio.h"
#include "cio_inject.h"
static inline int __stsch(struct subchannel_id schid, struct schib *addr)
{
register struct subchannel_id reg1 asm ("1") = schid;
int ccode = -EIO;
asm volatile(
" stsch 0(%3)\n"
"0: ipm %0\n"
" srl %0,28\n"
"1:\n"
EX_TABLE(0b, 1b)
: "+d" (ccode), "=m" (*addr)
: "d" (reg1), "a" (addr)
: "cc");
return ccode;
}
int stsch(struct subchannel_id schid, struct schib *addr)
{
int ccode;
ccode = __stsch(schid, addr);
trace_s390_cio_stsch(schid, addr, ccode);
return ccode;
}
EXPORT_SYMBOL(stsch);
static inline int __msch(struct subchannel_id schid, struct schib *addr)
{
register struct subchannel_id reg1 asm ("1") = schid;
int ccode = -EIO;
asm volatile(
" msch 0(%2)\n"
"0: ipm %0\n"
" srl %0,28\n"
"1:\n"
EX_TABLE(0b, 1b)
: "+d" (ccode)
: "d" (reg1), "a" (addr), "m" (*addr)
: "cc");
return ccode;
}
int msch(struct subchannel_id schid, struct schib *addr)
{
int ccode;
ccode = __msch(schid, addr);
trace_s390_cio_msch(schid, addr, ccode);
return ccode;
}
static inline int __tsch(struct subchannel_id schid, struct irb *addr)
{
register struct subchannel_id reg1 asm ("1") = schid;
int ccode;
asm volatile(
" tsch 0(%3)\n"
" ipm %0\n"
" srl %0,28"
: "=d" (ccode), "=m" (*addr)
: "d" (reg1), "a" (addr)
: "cc");
return ccode;
}
int tsch(struct subchannel_id schid, struct irb *addr)
{
int ccode;
ccode = __tsch(schid, addr);
trace_s390_cio_tsch(schid, addr, ccode);
return ccode;
}
static inline int __ssch(struct subchannel_id schid, union orb *addr)
{
register struct subchannel_id reg1 asm("1") = schid;
int ccode = -EIO;
asm volatile(
" ssch 0(%2)\n"
"0: ipm %0\n"
" srl %0,28\n"
"1:\n"
EX_TABLE(0b, 1b)
: "+d" (ccode)
: "d" (reg1), "a" (addr), "m" (*addr)
: "cc", "memory");
return ccode;
}
int ssch(struct subchannel_id schid, union orb *addr)
{
int ccode;
ccode = __ssch(schid, addr);
trace_s390_cio_ssch(schid, addr, ccode);
return ccode;
}
EXPORT_SYMBOL(ssch);
static inline int __csch(struct subchannel_id schid)
{
register struct subchannel_id reg1 asm("1") = schid;
int ccode;
asm volatile(
" csch\n"
" ipm %0\n"
" srl %0,28"
: "=d" (ccode)
: "d" (reg1)
: "cc");
return ccode;
}
int csch(struct subchannel_id schid)
{
int ccode;
ccode = __csch(schid);
trace_s390_cio_csch(schid, ccode);
return ccode;
}
EXPORT_SYMBOL(csch);
int tpi(struct tpi_info *addr)
{
int ccode;
asm volatile(
" tpi 0(%2)\n"
" ipm %0\n"
" srl %0,28"
: "=d" (ccode), "=m" (*addr)
: "a" (addr)
: "cc");
trace_s390_cio_tpi(addr, ccode);
return ccode;
}
int chsc(void *chsc_area)
{
typedef struct { char _[4096]; } addr_type;
int cc = -EIO;
asm volatile(
" .insn rre,0xb25f0000,%2,0\n"
"0: ipm %0\n"
" srl %0,28\n"
"1:\n"
EX_TABLE(0b, 1b)
: "+d" (cc), "=m" (*(addr_type *) chsc_area)
: "d" (chsc_area), "m" (*(addr_type *) chsc_area)
: "cc");
trace_s390_cio_chsc(chsc_area, cc);
return cc;
}
EXPORT_SYMBOL(chsc);
static inline int __rsch(struct subchannel_id schid)
{
register struct subchannel_id reg1 asm("1") = schid;
int ccode;
asm volatile(
" rsch\n"
" ipm %0\n"
" srl %0,28"
: "=d" (ccode)
: "d" (reg1)
: "cc", "memory");
return ccode;
}
int rsch(struct subchannel_id schid)
{
int ccode;
ccode = __rsch(schid);
trace_s390_cio_rsch(schid, ccode);
return ccode;
}
static inline int __hsch(struct subchannel_id schid)
{
register struct subchannel_id reg1 asm("1") = schid;
int ccode;
asm volatile(
" hsch\n"
" ipm %0\n"
" srl %0,28"
: "=d" (ccode)
: "d" (reg1)
: "cc");
return ccode;
}
int hsch(struct subchannel_id schid)
{
int ccode;
ccode = __hsch(schid);
trace_s390_cio_hsch(schid, ccode);
return ccode;
}
EXPORT_SYMBOL(hsch);
static inline int __xsch(struct subchannel_id schid)
{
register struct subchannel_id reg1 asm("1") = schid;
int ccode;
asm volatile(
" xsch\n"
" ipm %0\n"
" srl %0,28"
: "=d" (ccode)
: "d" (reg1)
: "cc");
return ccode;
}
int xsch(struct subchannel_id schid)
{
int ccode;
ccode = __xsch(schid);
trace_s390_cio_xsch(schid, ccode);
return ccode;
}
static inline int __stcrw(struct crw *crw)
{
int ccode;
asm volatile(
" stcrw 0(%2)\n"
" ipm %0\n"
" srl %0,28\n"
: "=d" (ccode), "=m" (*crw)
: "a" (crw)
: "cc");
return ccode;
}
static inline int _stcrw(struct crw *crw)
{
#ifdef CONFIG_CIO_INJECT
if (static_branch_unlikely(&cio_inject_enabled)) {
if (stcrw_get_injected(crw) == 0)
return 0;
}
#endif
return __stcrw(crw);
}
int stcrw(struct crw *crw)
{
int ccode;
ccode = _stcrw(crw);
trace_s390_cio_stcrw(crw, ccode);
return ccode;
}