- 07 Dec, 2009 40 commits
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Stefan Weinhuber authored
The first DASD that is set online for a specific logical control unit has to do certain setup steps on the storage server to make full use of it, for example it will enable PAV. The features and characteristics reported by the storage server will depend on this setup, so all other devices on the same LCU will need to wait for the setup to be finished. Signed-off-by:
Stefan Weinhuber <wein@de.ibm.com> Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com>
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Stefan Haberland authored
Remove strings from s390 debugfeature entries that could lead to a crash when the data is read from dbf because the strings do not exist any more. Signed-off-by:
Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by:
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Stefan Weinhuber authored
Most of the error conditions reported by a FICON storage server indicate situations which can be recovered. Sometimes the host just needs to retry an I/O request, but sometimes the recovery is more complex and requires the device driver to wait, choose a different path, etc. The DASD device driver has a fully featured error recovery for normal block layer I/O, but not for internal I/O request which are for example used during the device bring up. This can lead to situations where the IPL of a system fails because DASD devices are not properly recognized. This patch will extend the internal I/O handling to use the existing error recovery procedures. Signed-off-by:
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Stefan Weinhuber authored
The DASD device driver needs to explicitly enable the prefix command on the storage server, before it can be used. Originally we enabled this command along with others only if we wanted to support PAV. However, today we require this command for other features like High Performance FICON as well, so we need to always enable prefix. Signed-off-by:
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Christian Borntraeger authored
the todclk.h header file is dead code. Remove it. Signed-off-by:
Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by:
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Stefan Weinhuber authored
When a DASD device is used with the DIAG discipline, the DIAG initialization will indicate success or error with a respective return code. So far we have interpreted a return code of 4 as error, but it actually means that the initialization was successful, but the device is read-only. To allow read-only devices to be used with DIAG we need to accept a return code of 4 as success. Re-initialization of the DIAG access is also part of the DIAG error recovery. If we find that the access mode of a device has been changed from writable to read-only while the device was in use, we print an error message. Signed-off-by:
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Gerald Schaefer authored
The pagetable walk usercopy functions have used a modified copy of the do_exception() function for fault handling. This lead to inconsistencies with recent changes to do_exception(), e.g. performance counters. This patch changes the pagetable walk usercopy code to call do_exception() directly, eliminating the redundancy. A new parameter is added to do_exception() to specify the fault address. Signed-off-by:
Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by:
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Martin Schwidefsky authored
Simplify the check of the vma->flags in do_exception for the different fault types. Signed-off-by: -
Martin Schwidefsky authored
Slim down the do_exception function to handle only the fast path of a fault and move the exceptional cases into a new function. That slightly increases the performance of the fault handling. Build fix for !CONFIG_COMPAT by Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Signed-off-by: -
Martin Schwidefsky authored
notify_page_fault does a preempt_disable/preempt_enable for each fault generated by a kernel access to user space. If kprobes is not active that is unnecessary since the interrupts are not reenabled yet. To play safe repeat the kprobe_running check after preempt_disable(). Signed-off-by: -
Martin Schwidefsky authored
Introduce user_mode to replace the two variables switch_amode and s390_noexec. There are three valid combinations of the old values: 1) switch_amode == 0 && s390_noexec == 0 2) switch_amode == 1 && s390_noexec == 0 3) switch_amode == 1 && s390_noexec == 1 They get replaced by 1) user_mode == HOME_SPACE_MODE 2) user_mode == PRIMARY_SPACE_MODE 3) user_mode == SECONDARY_SPACE_MODE The new kernel parameter user_mode=[primary,secondary,home] lets you choose the address space mode the user space processes should use. In addition the CONFIG_S390_SWITCH_AMODE config option is removed. Signed-off-by: -
Martin Schwidefsky authored
A data access in access-register mode always is a user mode access, the code to inspect the access-registers can be removed. The second change is to use a different test to check for no-execute fault. The third change is to pass the translation exception identification as parameter, in theory the trans_exc_code in the lowcore could have been overwritten by the time the call to check_space from do_no_context is done. Signed-off-by: -
Sebastian Ott authored
If we detect a busy subchannel after the driver's set_offline callback returned in ccw_device_set_offline, the current behavior is to unregister the device, which may lead to undesired consequences. Change this to just quiesce the subchannel and go on with the offline processing. Note: This is no excuse for not fixing these drivers - after the set_offline callback they should have no running IO! Signed-off-by:
Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by:
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Peter Oberparleiter authored
Improve error recovery for internal I/Os by repeating each I/O 256 times per path to cope with long-running non-permanent error conditions. Also retry each path twice to cope with link flapping, i.e. single paths becoming unavailable in the order in which they are tried. Signed-off-by:
Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by:
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Sebastian Ott authored
IO subchannels are always unregistered in process context, so use spin_lock_irq in the corresponding remove callback. Signed-off-by:
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Sebastian Ott authored
Ensure that there will be no more interrupts for an unregistered device by using the same quiesce and disable loop as in io_subchannel_shutdown. Signed-off-by:
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Sebastian Ott authored
Try to disable the old subchannel before we ask the driver core to move the attached device to a new parent. This way we can use the QUIESCE state during shutdown which prevents a possible use after free situation in some error cases. Signed-off-by:
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Sebastian Ott authored
Handle a failing cio_disable_subchannel at the end of our device recognition as if the recognition itself failed. This way subsequent registration steps do not need to handle enabled subchannels. Signed-off-by:
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Sebastian Ott authored
DEV_STATE_QUIESCE is used to stop all IO on a busy subchannel. This patch fixes the following problems related to the QUIESCE state: * Fix a potential race condition which could occur when the resulting state was DEV_STATE_OFFLINE. * Add missing locking around cio_disable_subchannel, ccw_device_cancel_halt_clear and the cdev's handler. * Loop until we know for sure that the subchannel is disabled. Signed-off-by:
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Sebastian Ott authored
The function ccw_device_unregister has to ensure to remove all references obtained by device_add and device_initialize. Unfortunately it gets called for devices which are 1) uninitialized, 2) initialized but unregistered, and 3) registered devices. To distinguish 1) and 2) this patch introduces a new flag "initialized", which is 1 as long as we hold the initial device reference. Signed-off-by:
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Sebastian Ott authored
We used to maintain a "registered" flag in our ccw_device_private structure. This patch removes the "registered" flag and converts all users of it to device_is_registered which has the exact same meaning. Note: The usage the atomic operation test_and_clear_bit is replaced by the non-atomic if (device_is_registered()) device_del(). This will not do harm, since we serialize calls to ccw_device_unregister with a single-threaded workqueue. Signed-off-by:
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Peter Oberparleiter authored
An Unconditional Reserve + Release operation (steal lock) for a boxed device may fail when encountering special error cases (e.g. unit checks or path errors). Fix this by using the more robust ccw_request infrastructure for performing the steal lock CCW program. Signed-off-by:
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Peter Oberparleiter authored
Set-pgid operations fail for some device types under z/VM for which the hypervisor has already set the pgid. Also reserved devices or changed pgids are not correctly recognized. Fix these problems by using a combination of sense-pgid and set-pgid and by also accepting pre-defined pgid settings. Signed-off-by:
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Peter Oberparleiter authored
Split setting (driver wants feature enabled) and status (feature setup was successful) for PGID related ccw device features so that setup errors can be detected. Previously, incorrectly handled setup errors could in rare cases lead to erratic I/O behavior and permanently unusuable devices. Signed-off-by:
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Peter Oberparleiter authored
After changing all internal I/O functions to use the newly introduced ccw request infrastructure, retries are handled automatically after a clear operation. Therefore remove the internal retry flag and associated code. Signed-off-by:
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Peter Oberparleiter authored
Accept a request for setting a not-operational device offline. This way, users can remove devices from Linux which would otherwise remain unusable until reboot. Signed-off-by:
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Peter Oberparleiter authored
Use the newly introduced ccw request infrastructure to implement pgid related operations: sense pgid, set pgid and disband pg. Signed-off-by:
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Peter Oberparleiter authored
Use the newly introduced ccw request infrastructure to implement the sense id operation. Signed-off-by:
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Peter Oberparleiter authored
Reduce code duplication by introducing a central infrastructure to perform an internal I/O operation on a CCW device. Signed-off-by:
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Peter Oberparleiter authored
Remove the call to BUG() for situations which are unexpected but do not cause actual problems. Signed-off-by:
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Peter Oberparleiter authored
Device recognition needs to be started with the ccw device lock held to prevent race conditions between I/O starting and interrupt reception. Signed-off-by:
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Peter Oberparleiter authored
Handle verification errors consistently through the existing callback ccw_device_done to reduce cleanup code duplication. Signed-off-by:
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Peter Oberparleiter authored
Remove the return code from ccw_device_recognition and handle recognition errors through the existing callback ccw_device_recog_done to reduce cleanup code duplication. Signed-off-by:
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Peter Oberparleiter authored
Print a warning message in case a ccw device enters boxed or not operational state during online/offline processing. Signed-off-by:
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Peter Oberparleiter authored
Introduce a central mechanism for performing delayed ccw device work to ensure that different types of work do not overwrite each other. Prioritization ensures that the most important work is always performed while less important tasks are either obsoleted or repeated later. Signed-off-by:
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Peter Oberparleiter authored
Ensure that current and future users of sch->work do not overwrite each other by introducing a single mechanism for delayed subchannel work. Signed-off-by:
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Peter Oberparleiter authored
Change the initiative to update subchannel-ccw device associations to the subchannel: when there is an indication that the internal association no longer reflects the current hardware state, mark each affected subchannel as requiring attention. Once processing reaches a subchannel, determine the correct association for that subchannel at that time and perform the necessary device_move operations. This change fixes problems with the previous approach which would leave devices in an inconsistent state when a new hardware change occurred while a device_move was already scheduled. Signed-off-by:
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Peter Oberparleiter authored
sch_create_and_recog_new_device() associates a parent subchannel with its ccw device child even though this is already done by the subsequently called io_subchannel_recog(). Also make sure io_subchannel_recog() sets the association under lock. Signed-off-by:
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Peter Oberparleiter authored
io_subchannel_probe() frees memory for sch->private which is later freed again when io_subchannel_remove() is called. Fix this problem by removing the cleanup in io_subchannel_probe(). Signed-off-by:
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Hendrik Brueckner authored
When the kernel is IPLed without the CLEAR option and switches to 64-bit, the high-order half of the registers might contain random values. This can cause addressing exceptions and the kernel enters an interrupt loop. Initialize the high-order half of the general purpose registers with zeros after switching to 64-bit mode. Cc: <stable@kernel.org> Signed-off-by:
Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by:
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