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path: root/drivers/s390/crypto/ap_queue.c
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2020-01-09s390/zcrypt: move ap device reset from bus to driver codeHarald Freudenberger
This patch moves the reset invocation of an ap device when fresh detected from the ap bus to the probe() function of the driver responsible for this device. The virtualisation of ap devices makes it necessary to remove unconditioned resets on fresh appearing apqn devices. It may be that such a device is already enabled for guest usage. So there may be a race condition between host ap bus and guest ap bus doing the reset. This patch moves the reset from the ap bus to the zcrypt drivers. So if there is no zcrypt driver bound to an ap device - for example the ap device is bound to the vfio device driver - the ap device is untouched passed to the vfio device driver. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-08-02s390/zcrypt: adjust switch fall through comments for -Wimplicit-fallthroughVasily Gorbik
Silence the following warnings when built with -Wimplicit-fallthrough=3 enabled by default since 5.3-rc2: In file included from ./include/linux/preempt.h:11, from ./include/linux/spinlock.h:51, from ./include/linux/mmzone.h:8, from ./include/linux/gfp.h:6, from ./include/linux/slab.h:15, from drivers/s390/crypto/ap_queue.c:13: drivers/s390/crypto/ap_queue.c: In function 'ap_sm_recv': ./include/linux/list.h:577:2: warning: this statement may fall through [-Wimplicit-fallthrough=] 577 | for (pos = list_first_entry(head, typeof(*pos), member); \ | ^~~ drivers/s390/crypto/ap_queue.c:147:3: note: in expansion of macro 'list_for_each_entry' 147 | list_for_each_entry(ap_msg, &aq->pendingq, list) { | ^~~~~~~~~~~~~~~~~~~ drivers/s390/crypto/ap_queue.c:155:2: note: here 155 | case AP_RESPONSE_NO_PENDING_REPLY: | ^~~~ drivers/s390/crypto/zcrypt_msgtype6.c: In function 'convert_response_ep11_xcrb': drivers/s390/crypto/zcrypt_msgtype6.c:871:6: warning: this statement may fall through [-Wimplicit-fallthrough=] 871 | if (msg->cprbx.cprb_ver_id == 0x04) | ^ drivers/s390/crypto/zcrypt_msgtype6.c:874:2: note: here 874 | default: /* Unknown response type, this should NEVER EVER happen */ | ^~~~~~~ drivers/s390/crypto/zcrypt_msgtype6.c: In function 'convert_response_rng': drivers/s390/crypto/zcrypt_msgtype6.c:901:6: warning: this statement may fall through [-Wimplicit-fallthrough=] 901 | if (msg->cprbx.cprb_ver_id == 0x02) | ^ drivers/s390/crypto/zcrypt_msgtype6.c:907:2: note: here 907 | default: /* Unknown response type, this should NEVER EVER happen */ | ^~~~~~~ drivers/s390/crypto/zcrypt_msgtype6.c: In function 'convert_response_xcrb': drivers/s390/crypto/zcrypt_msgtype6.c:838:6: warning: this statement may fall through [-Wimplicit-fallthrough=] 838 | if (msg->cprbx.cprb_ver_id == 0x02) | ^ drivers/s390/crypto/zcrypt_msgtype6.c:844:2: note: here 844 | default: /* Unknown response type, this should NEVER EVER happen */ | ^~~~~~~ drivers/s390/crypto/zcrypt_msgtype6.c: In function 'convert_response_ica': drivers/s390/crypto/zcrypt_msgtype6.c:801:6: warning: this statement may fall through [-Wimplicit-fallthrough=] 801 | if (msg->cprbx.cprb_ver_id == 0x02) | ^ drivers/s390/crypto/zcrypt_msgtype6.c:808:2: note: here 808 | default: /* Unknown response type, this should NEVER EVER happen */ | ^~~~~~~ Acked-by: Patrick Steuer <patrick.steuer@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-04-10s390/zcrypt: fix possible deadlock situation on ap queue removeHarald Freudenberger
With commit 01396a374c3d ("s390/zcrypt: revisit ap device remove procedure") the ap queue remove is now a two stage process. However, a del_timer_sync() call may trigger the timer function which may try to lock the very same spinlock as is held by the function just initiating the del_timer_sync() call. This could end up in a deadlock situation. Very unlikely but possible as you need to remove an ap queue at the exact sime time when a timeout of a request occurs. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reported-by: Pierre Morel <pmorel@linux.ibm.com> Fixes: commit 01396a374c3d ("s390/zcrypt: revisit ap device remove procedure") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-03-06s390/zcrypt: revisit ap device remove procedureHarald Freudenberger
Working with the vfio-ap driver let to some revisit of the way how an ap (queue) device is removed from the driver. With the current implementation all the cleanup was done before the driver even got notified about the removal. Now the ap queue removal is done in 3 steps: 1) A preparation step, all ap messages within the queue are flushed and so the driver does 'receive' them. Also a new state AP_STATE_REMOVE assigned to the queue makes sure there are no new messages queued in. 2) Now the driver's remove function is invoked and the driver should do the job of cleaning up it's internal administration lists or whatever. After 2) is done it is guaranteed, that the driver is not invoked any more. On the other hand the driver has to make sure that the APQN is not accessed any more after step 2 is complete. 3) Now the ap bus code does the job of total cleanup of the APQN. A reset with zero is triggered and the state of the queue goes to AP_STATE_UNBOUND. After step 3) is complete, the ap queue has no pending messages and the APQN is cleared and so there are no requests and replies lingering around in the firmware queue for this APQN. Also the interrupts are disabled. After these remove steps the ap queue device may be assigned to another driver. Stress testing this remove/probe procedure showed a problem with the correct module reference counting. The actual receive of an reply in the driver is done asynchronous with completions. So with a driver change on an ap queue the message flush triggers completions but the threads waiting for the completions may run at a time where the queue already has the new driver assigned. So the module_put() at receive time needs to be done on the driver module which queued the ap message. This change is also part of this patch. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-02-13s390/zcrypt: use new state UNBOUND during queue driver rebindHarald Freudenberger
When an alternate driver (vfio-ap) has bound an ap queue and this binding is revised the ap queue device is in an intermittent state not bound to any driver. The internal state variable covered this with the state AP_STATE_BORKED which is also used to reflect broken devices. When now an ap bus scan runs such a device is destroyed and on the next scan reconstructed. So a stress test with high frequency switching the queue driver between the default and the vfio-ap driver hit this gap and the queue was removed until the next ap bus scan. This fix now introduces another state for the in-between condition for a queue momentary not bound to a driver and so the ap bus scan function skips this device instead of removing it. Also some very slight but maybe helpful debug feature messages come with this patch - in particular a message showing that a broken card/queue device will get removed. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-12-13s390/zcrypt: make sysfs reset attribute trigger queue resetHarald Freudenberger
Until now there is no way to reset a AP queue or card. Driving a card or queue offline and online again does only toggle the 'software' online state. The only way to trigger a (hardware) reset is by running hot-unplug/hot-plug for example on the HMC. This patch makes the queue reset attribute in sysfs writable. Writing into this attribute triggers a reset on the AP queue's state machine. So the AP queue is flushed and state machine runs through the initial states which cause a reset (PQAP(RAPQ)) and a re-registration to interrupts (PQAP(AQIC)) if available. The reset sysfs attribute is writable by root only. So only an administrator is allowed to initiate a reset of AP queues. Please note that the queue's counter values are left untouched by the reset. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-11-27s390/zcrypt: reinit ap queue state machine during device probeHarald Freudenberger
Until the vfio-ap driver came into live there was a well known agreement about the way how ap devices are initialized and their states when the driver's probe function is called. However, the vfio device driver when receiving an ap queue device does additional resets thereby removing the registration for interrupts for the ap device done by the ap bus core code. So when later the vfio driver releases the device and one of the default zcrypt drivers takes care of the device the interrupt registration needs to get renewed. The current code does no renew and result is that requests send into such a queue will never see a reply processed - the application hangs. This patch adds a function which resets the aq queue state machine for the ap queue device and triggers the walk through the initial states (which are reset and registration for interrupts). This function is now called before the driver's probe function is invoked. When the association between driver and device is released, the driver's remove function is called. The current implementation calls a ap queue function ap_queue_remove(). This invokation has been moved to the ap bus function to make the probe / remove pair for ap bus and drivers more symmetric. Fixes: 7e0bdbe5c21c ("s390/zcrypt: AP bus support for alternate driver(s)") Cc: stable@vger.kernel.org # 4.19+ Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewd-by: Tony Krowiak <akrowiak@linux.ibm.com> Reviewd-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-08-20s390/zcrypt: code beautifyHarald Freudenberger
Code beautify by following most of the checkpatch suggestions: - SPDX license identifier line complains by checkpatch - missing space or newline complains by checkpatch - octal numbers for permssions complains by checkpatch - renaming of static sysfs functions complains by checkpatch - fix of block comment complains by checkpatch - fix printf like calls where function name instead of %s __func__ was used - __packed instead of __attribute__((packed)) - init to zero for static variables removed - use of DEVICE_ATTR_RO and DEVICE_ATTR_RW macros No functional code changes or API changes! Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-06-25s390/zcrypt: Integrate ap_asm.h into include/asm/ap.h.Harald Freudenberger
Move all the inline functions from the ap bus header file ap_asm.h into the in-kernel api header file arch/s390/include/asm/ap.h so that KVM can make use of all the low level AP functions. Signed-off-by: Harald Freudenberger <freude@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-14s390/ap_bus: Convert timers to use timer_setup()Kees Cook
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Cc: Harald Freudenberger <freude@de.ibm.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2017-11-13Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Heiko Carstens: "Since Martin is on vacation you get the s390 pull request for the v4.15 merge window this time from me. Besides a lot of cleanups and bug fixes these are the most important changes: - a new regset for runtime instrumentation registers - hardware accelerated AES-GCM support for the aes_s390 module - support for the new CEX6S crypto cards - support for FORTIFY_SOURCE - addition of missing z13 and new z14 instructions to the in-kernel disassembler - generate opcode tables for the in-kernel disassembler out of a simple text file instead of having to manually maintain those tables - fast memset16, memset32 and memset64 implementations - removal of named saved segment support - hardware counter support for z14 - queued spinlocks and queued rwlocks implementations for s390 - use the stack_depth tracking feature for s390 BPF JIT - a new s390_sthyi system call which emulates the sthyi (store hypervisor information) instruction - removal of the old KVM virtio transport - an s390 specific CPU alternatives implementation which is used in the new spinlock code" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (88 commits) MAINTAINERS: add virtio-ccw.h to virtio/s390 section s390/noexec: execute kexec datamover without DAT s390: fix transactional execution control register handling s390/bpf: take advantage of stack_depth tracking s390: simplify transactional execution elf hwcap handling s390/zcrypt: Rework struct ap_qact_ap_info. s390/virtio: remove unused header file kvm_virtio.h s390: avoid undefined behaviour s390/disassembler: generate opcode tables from text file s390/disassembler: remove insn_to_mnemonic() s390/dasd: avoid calling do_gettimeofday() s390: vfio-ccw: Do not attempt to free no-op, test and tic cda. s390: remove named saved segment support s390/archrandom: Reconsider s390 arch random implementation s390/pci: do not require AIS facility s390/qdio: sanitize put_indicator s390/qdio: use atomic_cmpxchg s390/nmi: avoid using long-displacement facility s390: pass endianness info to sparse s390/decompressor: remove informational messages ...
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-23s390/zcrypt: Introduce QACT support for AP bus devices.Harald Freudenberger
This patch introduces a new ap_qact() function which exploits the PQAP(QACT) subfunction. QACT is a new interface to Query the Ap Compatilibity Type based on a given AP qid, type, mode and version. Based on this new function the AP bus scan code is slightly reworked to use this new interface for querying the compatible type for each new AP queue device detected. So new and unknown devices can get automatically mapped to a compatible type and handled without the need for toleration patches for every new hardware. The currently highest known hardware is CEX6S. With this patch a possible successor can get queried for a combatible type known by the device driver without the need for an toleration patch. Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-10-23s390/zcrypt: CEX6S exploitationHarald Freudenberger
This patch adds the full CEX6S card support to the zcrypt device driver. A CEX6A/C/P is detected and displayed as such, the card and queue device driver code is updated to recognize it and the relative weight values for CEX4, CEX5 and CEX6 have been updated. Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-09-06s390/zcrypt: externalize AP queue interrupt controlHarald Freudenberger
KVM has a need to control the interrupts on real and virtualized AP queue devices. This fix provides a new function to control the interrupt facilities of an AP queue device. Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-09-06s390/zcrypt: externalize test AP queueTony Krowiak
Under certain specified conditions, the Test AP Queue (TAPQ) subfunction of the Process Adjunct Processor Queue (PQAP) instruction will be intercepted by a guest VM. The guest VM must have a means for executing the intercepted instruction. The vfio_ap driver will provide an interface to execute the PQAP(TAPQ) instruction subfunction on behalf of a guest VM. The code for executing the AP instructions currently resides in the AP bus. This patch refactors the AP bus code to externalize access to the PQAP(TAPQ) instruction subfunction to make it available to the vfio_ap driver. Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com> Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-06-02s390/zcrypt: Fix blocking queue device after unbind/bind.Harald Freudenberger
When the association between a queue device and the driver is released via unbind and later re-associated the queue device was not operational any more. Reason was a wrong administration of the card/queue lists within the ap device driver. This patch introduces revised card/queue list handling within the ap device driver: when an ap device is detected it is initial not added to the card/queue list any more. With driver probe the card device is added to the card list/the queue device is added to the queue list within a card. With driver remove the device is removed from the card/queue list. Additionally there are some situations within the ap device live where the lists need update upon card/queue device release (for example device hot unplug or suspend/resume). Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-02-23s390/zcrypt: Enable request count reset for cards and queues.Harald Freudenberger
This patch introduces the possibility to reset the request_count attribute for cards and queues to zero. This can be used to set a clear state on the counters before running an application and try out if and which hardware is actually used. If the request_count counter of a card is reset, for all associated queues the request_count is also zeroed. If just a queue request_count is reset the card counter is not updated however. Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-01-16s390/zcrypt: make structures staticHeiko Carstens
Get rid of these: drivers/s390/crypto/ap_card.c:140:20: warning: symbol 'ap_card_type' was not declared. Should it be static? drivers/s390/crypto/ap_queue.c:567:20: warning: symbol 'ap_queue_type' was not declared. Should it be static? Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-12-14s390/zcrypt: Fixed attrition of AP adapters and domainsIngo Tuchscherer
Currently the first eligible AP adapter respectively domain will be selected to service requests. In case of sequential workload, the very same adapter/domain will be used. The adapter/domain selection algorithm now considers the completed transactions per adaper/domain and therefore ensures a homogeneous utilization. Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-12-14s390/zcrypt: add multi domain supportIngo Tuchscherer
Currently the ap infrastructure only supports one domain at a time. This feature extends the generic cryptographic device driver to support multiple cryptographic domains simultaneously. There are now card and queue devices on the AP bus with independent card and queue drivers. The new /sys layout is as follows: /sys/bus/ap devices <xx>.<yyyy> -> ../../../devices/ap/card<xx>/<xx>.<yyyy> ... card<xx> -> ../../../devices/ap/card<xx> ... drivers <drv>card card<xx> -> ../../../../devices/ap/card<xx> <drv>queue <xx>.<yyyy> -> ../../../../devices/ap/card<xx>/<xx>.<yyyy> ... /sys/devices/ap card<xx> <xx>.<yyyy> driver -> ../../../../bus/ap/drivers/<zzz>queue ... driver -> ../../../bus/ap/drivers/<drv>card ... The two digit <xx> field is the card number, the four digit <yyyy> field is the queue number and <drv> is the name of the device driver, e.g. "cex4". For compatability /sys/bus/ap/card<xx> for the old layout has to exist, including the attributes that used to reside there. With additional contributions from Harald Freudenberger and Martin Schwidefsky. Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>