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a4f17cc726
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>
26 lines
725 B
Plaintext
26 lines
725 B
Plaintext
# SPDX-License-Identifier: GPL-2.0
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config TRACE_IRQFLAGS_SUPPORT
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def_bool y
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config EARLY_PRINTK
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def_bool y
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config DEBUG_ENTRY
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bool "Debug low-level entry code"
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depends on DEBUG_KERNEL
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help
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This option enables sanity checks in s390 low-level entry code.
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Some of these sanity checks may slow down kernel entries and
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exits or otherwise impact performance.
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If unsure, say N.
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config CIO_INJECT
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bool "CIO Inject interfaces"
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depends on DEBUG_KERNEL && DEBUG_FS
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help
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This option provides a debugging facility to inject certain artificial events
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and instruction responses to the CIO layer of Linux kernel. The newly created
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debugfs user-interfaces will be at /sys/kernel/debug/s390/cio/*
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