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path: root/drivers/scsi/cxlflash/main.c
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2016-09-14scsi: cxlflash: Refactor WWPN setupMatthew R. Ochs
Commit 964497b3bf3f ("cxlflash: Remove dual port online dependency") logically removed the ability for the WWPN setup routine afu_set_wwpn() to return a non-success value. This routine can safely be made a void to simplify the code as there is no longer a need to report a failure. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-09-14scsi: cxlflash: Improve EEH recovery timeMatthew R. Ochs
When an EEH occurs during device initialization, the port timeout logic can cause excessive delays as MMIO reads will fail. Depending on where they are experienced, these delays can lead to a prolonged reset, causing an unnecessary triggering of other timeout logic in the SCSI stack or user applications. To expedite recovery, the port timeout logic is updated to decay the timeout at a much faster rate when in the presence of a likely EEH frozen event. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-09-14scsi: cxlflash: Fix to avoid EEH and host reset collisionsMatthew R. Ochs
The EEH reset handler is ignorant to the current state of the driver when processing a frozen event and initiating a device reset. This can be an issue if an EEH event occurs while a user or stack initiated reset is executing. More specifically, if an EEH occurs while the SCSI host reset handler is active, the reset initiated by the EEH thread will likely collide with the host reset thread. This can leave the device in an inconsistent state, or worse, cause a system crash. As a remedy, the EEH handler is updated to evaluate the device state and take appropriate action (proceed, wait, or disconnect host). The host reset handler is also updated to handle situations where an EEH occurred during a host reset. In such situations, the host reset handler will delay reporting back a success to give the EEH reset an opportunity to complete. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-09-09scsi: cxlflash: Remove the device cleanly in the system shutdown pathUma Krishnan
Commit 704c4b0ddc03 ("cxlflash: Shutdown notify support for CXL Flash cards") was recently introduced to notify the AFU when a system is going down. Due to the position of the cxlflash driver in the device stack, cxlflash devices are _always_ removed during a reboot/shutdown. This can lead to a crash if the cxlflash shutdown hook is invoked _after_ the shutdown hook for the owning virtual PHB. Furthermore, the current implementation of shutdown/remove hooks for cxlflash are not tolerant to being invoked when the device is not enabled. This can also lead to a crash in situations where the remove hook is invoked after the device has been removed via the vPHBs shutdown hook. An example of this scenario would be an EEH reset failure while a reboot/shutdown is in progress. To solve both problems, the shutdown hook for cxlflash is updated to simply remove the device. This path already includes the AFU notification and thus this solution will continue to perform the original intent. At the same time, the remove hook is updated to protect against being called when the device is not enabled. Fixes: 704c4b0ddc03 ("cxlflash: Shutdown notify support for CXL Flash cards") Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-09-09scsi: cxlflash: Scan host only after the port is ready for I/OUma Krishnan
When a port link is established, the AFU sends a 'link up' interrupt. After the link is up, corresponding initialization steps are performed on the card. Following that, when the card is ready for I/O, the AFU sends 'login succeeded' interrupt. Today, cxlflash invokes scsi_scan_host() upon receipt of both interrupts. SCSI commands sent to the port prior to the 'login succeeded' interrupt will fail with 'port not available' error. This is not desirable. Moreover, when async_scan is active for the host, subsequent scan calls are terminated with error. Due to this, the scsi_scan_host() call performed after 'login succeeded' interrupt could portentially return error and the devices may not be scanned properly. To avoid this problem, scsi_scan_host() should be called only after the 'login succeeded' interrupt. Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-07-27cxlflash: Verify problem state area is mapped before notifying shutdownUma Krishnan
If an EEH or some other hard error occurs while the adapter instance was being initialized, on the subsequent shutdown of the device, the system could crash with: [c000000f1da03b60] c0000000005eccfc pci_device_shutdown+0x6c/0x100 [c000000f1da03ba0] c0000000006d67d4 device_shutdown+0x1b4/0x2c0 [c000000f1da03c40] c0000000000ea30c kernel_restart_prepare+0x5c/0x80 [c000000f1da03c70] c0000000000ea48c kernel_restart+0x2c/0xc0 [c000000f1da03ce0] c0000000000ea970 SyS_reboot+0x1c0/0x2d0 [c000000f1da03e30] c000000000009204 system_call+0x38/0xb4 This crash is due to the AFU not being mapped when the shutdown notification routine is called and is a regression that was inserted recently with Commit 704c4b0ddc03 ("cxlflash: Shutdown notify support for CXL Flash cards"). As a fix, shutdown notification should only occur when the AFU is mapped. Fixes: 704c4b0ddc03 ("cxlflash: Shutdown notify support for CXL Flash cards") Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-07-12cxlflash: Shutdown notify support for CXL Flash cardsUma Krishnan
Some CXL Flash cards need notification of device shutdown in order to flush pending I/Os. A PCI notification hook for shutdown has been added where the driver notifies the card and returns. When the device is removed in the PCI remove path, notification code will wait for shutdown processing to complete. Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Acked-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-07-12cxlflash: Add device dependent flagsUma Krishnan
Device dependent flags are needed to support functions that are specific to a particular device. One such case is - some CXL Flash cards need to be notified of device shutdown. For other CXL devices, this feature does not prove to be useful yet. Such distinct features need to be identified in the driver to bypass or invoke specific functionality. In this patch, a member 'flags' has been added to device dependent values. These flags will be used and expanded in the future to support various device specific functions. Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Acked-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-07-12cxlflash: Fix to drain operations from previous resetManoj N. Kumar
While running 'sg_reset -H' in a loop with a user-space application active, hit the following exception: cpu 0x2: Vector: 300 (Data Access) pc: : afu_attach+0x50/0x240 [cxlflash] lr: : cxlflash_afu_recover+0x3dc/0x7d0 [cxlflash] pid = 20365, comm = run_block_fvt Linux version 4.5.0-491-26f710d+ cxlflash_afu_recover+0x3dc/0x7d0 [cxlflash] cxlflash_ioctl+0x5a8/0x6f0 [cxlflash] scsi_ioctl+0x3b0/0x4c0 sd_ioctl+0x110/0x190 blkdev_ioctl+0x28c/0xc20 block_ioctl+0xa4/0xd0 do_vfs_ioctl+0xd8/0x8c0 SyS_ioctl+0xd4/0xf0 system_call+0x38/0xb4 The problem here is that the problem space area is unmapped while the application issues the DK_CXLFLASH_RECOVER_AFU ioctl. This is the order I observe: proc1 proc2 1) sg_reset 2) ioctl(DK_CXLFLASH_RECOVER_AFU) 3) sg_reset again causing a PSA unmap 4) continues RECOVER_AFU processing The resolution to this problem is to have the reset handler drain all outstanding user space initiated ioctls before proceeding. It is safe to drain after the state has been changed to STATE_RESET. Also since drain_ioctls() was static, it had to be moved up a bit to be before cxlflash_eh_host_reset_handler(). Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-04-05Merge branch 'fixes-base' into fixesJames Bottomley
2016-03-28cxlflash: Move to exponential back-off when cmd_room is not availableManoj N. Kumar
While profiling the cxlflash_queuecommand() path under a heavy load it was found that number of retries to find cmd_room was fairly high. There are two problems with the current back-off: a) It starts with a udelay of 0 b) It backs-off linearly Tried several approaches (a higher multiple 10*n, 100*n, as well as n^2, 2^n) and found that the exponential back-off(2^n) approach had the least overall cost. Cost as being defined as overall time spent waiting. The fix is to change the linear back-off to an exponential back-off. This solution also takes care of the problem with the initial delay (starts with 1 usec). Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-28cxlflash: Fix regression issue with re-ordering patchManoj N. Kumar
While running 'sg_reset -H' back to back the following exception was seen: [ 735.115695] Faulting instruction address: 0xd0000000098c0864 cpu 0x0: Vector: 300 (Data Access) at [c000000ffffafa80] pc: d0000000098c0864: cxlflash_async_err_irq+0x84/0x5c0 [cxlflash] lr: c00000000013aed0: handle_irq_event_percpu+0xa0/0x310 sp: c000000ffffafd00 msr: 9000000000009033 dar: 2010000 dsisr: 40000000 current = 0xc000000001510880 paca = 0xc00000000fb80000 softe: 0 irq_happened: 0x01 pid = 0, comm = swapper/0 Linux version 4.5.0-491-26f710d+ enter ? for help [c000000ffffafe10] c00000000013aed0 handle_irq_event_percpu+0xa0/0x310 [c000000ffffafed0] c00000000013b1a8 handle_irq_event+0x68/0xc0 [c000000ffffaff00] c0000000001404ec handle_fasteoi_irq+0xec/0x2a0 [c000000ffffaff30] c00000000013a084 generic_handle_irq+0x54/0x80 [c000000ffffaff60] c000000000011130 __do_irq+0x80/0x1d0 [c000000ffffaff90] c000000000024d40 call_do_irq+0x14/0x24 [c000000001573a20] c000000000011318 do_IRQ+0x98/0x140 [c000000001573a70] c000000000002594 hardware_interrupt_common+0x114/0x180 This exception is being hit because the async_err interrupt path performs an MMIO to read the interrupt status register. The MMIO region in this case is not available. Commit 6ded8b3cbd9a ("cxlflash: Unmap problem state area before detaching master context") re-ordered the sequence in which term_mc() and stop_afu() are called. This introduces a window for interrupts to come in with the problem space area unmapped, that did not exist previously. The fix is to separate the disabling of all AFU interrupts to a distinct function, term_intr() so that it is the first thing that is done in the tear down process. To keep the initialization process symmetric, separate the AFU interrupt setup also to a distinct function: init_intr(). Fixes: 6ded8b3cbd9a ("cxlflash: Unmap problem state area before detaching master context") Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-19Merge tag 'powerpc-4.6-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "This was delayed a day or two by some build-breakage on old toolchains which we've now fixed. There's two PCI commits both acked by Bjorn. There's one commit to mm/hugepage.c which is (co)authored by Kirill. Highlights: - Restructure Linux PTE on Book3S/64 to Radix format from Paul Mackerras - Book3s 64 MMU cleanup in preparation for Radix MMU from Aneesh Kumar K.V - Add POWER9 cputable entry from Michael Neuling - FPU/Altivec/VSX save/restore optimisations from Cyril Bur - Add support for new ftrace ABI on ppc64le from Torsten Duwe Various cleanups & minor fixes from: - Adam Buchbinder, Andrew Donnellan, Balbir Singh, Christophe Leroy, Cyril Bur, Luis Henriques, Madhavan Srinivasan, Pan Xinhui, Russell Currey, Sukadev Bhattiprolu, Suraj Jitindar Singh. General: - atomics: Allow architectures to define their own __atomic_op_* helpers from Boqun Feng - Implement atomic{, 64}_*_return_* variants and acquire/release/ relaxed variants for (cmp)xchg from Boqun Feng - Add powernv_defconfig from Jeremy Kerr - Fix BUG_ON() reporting in real mode from Balbir Singh - Add xmon command to dump OPAL msglog from Andrew Donnellan - Add xmon command to dump process/task similar to ps(1) from Douglas Miller - Clean up memory hotplug failure paths from David Gibson pci/eeh: - Redesign SR-IOV on PowerNV to give absolute isolation between VFs from Wei Yang. - EEH Support for SRIOV VFs from Wei Yang and Gavin Shan. - PCI/IOV: Rename and export virtfn_{add, remove} from Wei Yang - PCI: Add pcibios_bus_add_device() weak function from Wei Yang - MAINTAINERS: Update EEH details and maintainership from Russell Currey cxl: - Support added to the CXL driver for running on both bare-metal and hypervisor systems, from Christophe Lombard and Frederic Barrat. - Ignore probes for virtual afu pci devices from Vaibhav Jain perf: - Export Power8 generic and cache events to sysfs from Sukadev Bhattiprolu - hv-24x7: Fix usage with chip events, display change in counter values, display domain indices in sysfs, eliminate domain suffix in event names, from Sukadev Bhattiprolu Freescale: - Updates from Scott: "Highlights include 8xx optimizations, 32-bit checksum optimizations, 86xx consolidation, e5500/e6500 cpu hotplug, more fman and other dt bits, and minor fixes/cleanup" * tag 'powerpc-4.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (179 commits) powerpc: Fix unrecoverable SLB miss during restore_math() powerpc/8xx: Fix do_mtspr_cpu6() build on older compilers powerpc/rcpm: Fix build break when SMP=n powerpc/book3e-64: Use hardcoded mttmr opcode powerpc/fsl/dts: Add "jedec,spi-nor" flash compatible powerpc/T104xRDB: add tdm riser card node to device tree powerpc32: PAGE_EXEC required for inittext powerpc/mpc85xx: Add pcsphy nodes to FManV3 device tree powerpc/mpc85xx: Add MDIO bus muxing support to the board device tree(s) powerpc/86xx: Introduce and use common dtsi powerpc/86xx: Update device tree powerpc/86xx: Move dts files to fsl directory powerpc/86xx: Switch to kconfig fragments approach powerpc/86xx: Update defconfigs powerpc/86xx: Consolidate common platform code powerpc32: Remove one insn in mulhdu powerpc32: small optimisation in flush_icache_range() powerpc: Simplify test in __dma_sync() powerpc32: move xxxxx_dcache_range() functions inline powerpc32: Remove clear_pages() and define clear_page() inline ...
2016-03-09cxlflash: Use new cxl_pci_read_adapter_vpd() APIFrederic Barrat
To read the adapter VPD, drivers can't rely on pci config APIs, as it wouldn't work on powerVM. cxl introduced a new kernel API especially for this, so start using it. Co-authored-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Reviewed-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-03-08cxlflash: Increase cmd_per_lun for better throughputManoj N. Kumar
With the current value of cmd_per_lun at 16, the throughput over a single adapter is limited to around 150kIOPS. Increase the value of cmd_per_lun to 256 to improve throughput. With this change a single adapter is able to attain close to the maximum throughput (380kIOPS). Also change the number of RRQ entries that can be queued. Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-08cxlflash: Fix to avoid unnecessary scan with internal LUNsManoj N. Kumar
When switching to the internal LUN defined on the IBM CXL flash adapter, there is an unnecessary scan occurring on the second port. This scan leads to the following extra lines in the log: Dec 17 10:09:00 tul83p1 kernel: [ 3708.561134] cxlflash 0008:00:00.0: cxlflash_queuecommand: (scp=c0000000fc1f0f00) 11/1/0/0 cdb=(A0000000-00000000-10000000-00000000) Dec 17 10:09:00 tul83p1 kernel: [ 3708.561147] process_cmd_err: cmd failed afu_rc=32 scsi_rc=0 fc_rc=0 afu_extra=0xE, scsi_extra=0x0, fc_extra=0x0 By definition, both of the internal LUNs are on the first port/channel. When the lun_mode is switched to internal LUN the same value for host->max_channel is retained. This causes an unnecessary scan over the second port/channel. This fix alters the host->max_channel to 0 (1 port), if internal LUNs are configured and switches it back to 1 (2 ports) while going back to external LUNs. Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-08cxlflash: Unmap problem state area before detaching master contextUma Krishnan
When operating in the PowerVM environment, the cxlflash module can receive an error from the hypervisor indicating that there are existing mappings in the page table for the process MMIO space. This issue exists because term_afu() currently invokes term_mc() before stop_afu(), allowing for the master context to be detached first and the problem state area to be unmapped second. To resolve this issue, stop_afu() should be called before term_mc(). Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-08cxlflash: Simplify PCI registrationManoj N. Kumar
The calls to pci_request_regions(), pci_resource_start(), pci_set_dma_mask(), pci_set_master() and pci_save_state() are all unnecessary for the IBM CXL flash adapter since data buffers are not required to be mapped to the device's memory. The use of services such as pci_set_dma_mask() are problematic on hypervisor managed systems as the IBM CXL flash adapter is operating under a virtual PCI Host Bridge (virtual PHB) which does not support these services. cxlflash 0001:00:00.0: init_pci: Failed to set PCI DMA mask rc=-5 The resolution is to simplify init_pci(), to a point where it does the bare minimum (pci_enable_device). Similarly, remove the call the pci_release_regions() from cxlflash_remove(). Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06cxlflash: Enable device id for future IBM CXL adapterManoj Kumar
This drop enables a future card with a device id of 0x0600 to be recognized by the cxlflash driver. As per the design, the Accelerator Function Unit (AFU) for this new IBM CXL Flash Adapter retains the same host interface as the previous generation. For the early prototypes of the new card, the driver with this change behaves exactly as the driver prior to this behaved with the earlier generation card. Therefore, no card specific programming has been added. These card specific changes can be staged in later if needed. Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06cxlflash: Resolve oops in wait_port_offlineManoj Kumar
If an async error interrupt is generated, and the error requires the FC link to be reset, it cannot be performed in the interrupt context. So a work element is scheduled to complete the link reset in a process context. If either an EEH event or an escalation occurs in between when the interrupt is generated and the scheduled work is started, the MMIO space may no longer be available. This will cause an oops in the worker thread. [ 606.806583] NIP kthread_data+0x28/0x40 [ 606.806633] LR wq_worker_sleeping+0x30/0x100 [ 606.806694] Call Trace: [ 606.806721] 0x50 (unreliable) [ 606.806796] wq_worker_sleeping+0x30/0x100 [ 606.806884] __schedule+0x69c/0x8a0 [ 606.806959] schedule+0x44/0xc0 [ 606.807034] do_exit+0x770/0xb90 [ 606.807109] die+0x300/0x460 [ 606.807185] bad_page_fault+0xd8/0x150 [ 606.807259] handle_page_fault+0x2c/0x30 [ 606.807338] wait_port_offline.constprop.12+0x60/0x130 [cxlflash] To prevent the problem space area from being unmapped, when there is pending work, a mapcount (using the kref mechanism) is held. The mapcount is released only when the work is completed. The last reference release is tied to the unmapping service. Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06cxlflash: Fix to resolve cmd leak after host resetManoj Kumar
After a few iterations of resetting the card, either during EEH recovery, or a host_reset the following is seen in the logs. cxlflash 0008:00: cxlflash_queuecommand: could not get a free command At every reset of the card, the commands that are outstanding are being leaked. No effort is being made to reap these commands. A few more resets later, the above error message floods the logs and the card is rendered totally unusable as no free commands are available. Iterated through the 'cmd' queue and printed out the 'free' counter and found that on each reset certain commands were in-use and stayed in-use through subsequent resets. To resolve this issue, when the card is reset, reap all the commands that are active/outstanding. Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06cxlflash: Removed driver date printUma Krishnan
Having a date for the driver requires it to be updated quite often. Removing the date which is not necessary. Also made use of the existing symbol to print the driver name. Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06cxlflash: Fix to escalate LINK_RESET also on port 1Manoj Kumar
The original fix to escalate a 'login timed out' error to a LINK_RESET was only made for one of the two ports on the card. This fix resolves the same issue for the second port (port 1). Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2015-10-30cxlflash: Fix to avoid lock instrumentation rejectionMatthew R. Ochs
When running with lock instrumentation (e.g. lockdep), some of the instrumentation can become disabled at probe time for a cxlflash adapter. This is due to a missing lock registration for the tmf_slock. The fix is to call spin_lock_init() for the tmf_slock during probe. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Manoj Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Fix to escalate to LINK_RESET on login timeoutManoj Kumar
A 'login timed out' asynchronous error interrupt is generated if no response is seen to a FLOGI within 2 seconds. If the time out error is not escalated to a LINK_RESET the port will not be available for use. This fix provides the required escalation. Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Fix to avoid leaving dangling interrupt resourcesMatthew R. Ochs
When running with an unsupported AFU, the cxlflash driver fails the probe. When the driver is removed, the following Oops is encountered on a show_interrupts() thread: Call Trace: [c000001fba5a7a10] [0000000000000003] 0x3 (unreliable) [c000001fba5a7a60] [c00000000053dcf4] vsnprintf+0x204/0x4c0 [c000001fba5a7ae0] [c00000000030045c] seq_vprintf+0x5c/0xd0 [c000001fba5a7b20] [c00000000030051c] seq_printf+0x4c/0x60 [c000001fba5a7b50] [c00000000013e140] show_interrupts+0x370/0x4f0 [c000001fba5a7c10] [c0000000002ff898] seq_read+0xe8/0x530 [c000001fba5a7ca0] [c00000000035d5c0] proc_reg_read+0xb0/0x110 [c000001fba5a7cf0] [c0000000002ca74c] __vfs_read+0x6c/0x180 [c000001fba5a7d90] [c0000000002cb464] vfs_read+0xa4/0x1c0 [c000001fba5a7de0] [c0000000002cc51c] SyS_read+0x6c/0x110 [c000001fba5a7e30] [c000000000009204] system_call+0x38/0xb4 The Oops is due to not cleaning up correctly on the unsupported AFU error path, leaving various allocated and registered resources. In this case, interrupts are in a semi-allocated/registered state, which the show_interrupts() thread attempts to use. To fix, the cleanup logic in init_afu() is consolidated to error gates at the bottom of the function and the appropriate goto is added to each error path. As a mini side fix while refactoring in this routine, the else statement following the AFU version evaluation is eliminated as it is not needed. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Acked-by: Manoj Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Correct trace stringMatthew R. Ochs
The trace following the failure of alloc_mem() incorrectly identifies which function failed. This can lead to misdiagnosing a failure. Fix the string to correctly indicate that alloc_mem() failed. Reported-by: Brian King <brking@linux.vnet.ibm.com> Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Fix to avoid corrupting adapter fopsMatthew R. Ochs
The fops owned by the adapter can be corrupted in certain scenarios, opening a window where certain fops are temporarily NULLed before being reset to their proper value. This can potentially lead software to make incorrect decisions, leaving the user with the inability to function as intended. An example of this behavior can be observed when there are a number of users with a high rate of turn around (attach to LUN, perform an I/O, detach from LUN, repeat). Every so often a user is given a valid context and adapter file descriptor, but the file associated with the descriptor lacks the correct read permission bit (FMODE_CAN_READ) and thus the read system call bails before calling the valid read fop. Background: The fops is stored in the adapter structure to provide the ability to lookup the adapter structure from within the fop handler. CXL services use the file's private_data and at present, the CXL context does not have a private section. In an effort to limit areas of the cxlflash driver with code specific the superpipe function, a design choice was made to keep the details of the fops situated away from the legacy portions of the driver. This drove the behavior that the adapter fops is set at the beginning of the disk attach ioctl handler when there are no users present. The corruption that this fix remedies is due to the fact that the fops is initially defaulted to values found within a static structure. When the fops is handed down to the CXL services later in the attach path, certain services are patched. The fops structure remains correct until the user count drops to 0 and the fops is reset, triggering the process to repeat again. The user counts are tightly coupled with the creation and deletion of the user context. If multiple users perform a disk attach at the same time, when the user count is currently 0, some users can be in the middle of obtaining a file descriptor and have not yet reached the context creation code that [in addition to creating the context] increments the user count. Subsequent users coming in to perform the attach see that the user count is still 0, and reinitialize the fops, temporarily removing the patched fops. The users that are in the middle obtaining their file descriptor may then receive an invalid descriptor. The fix simply removes the user count altogether and moves the fops initialization to probe time such that it is only performed one time for the life of the adapter. In the future, if the CXL services adopt a private member for their context, that could be used to store the adapter structure reference and cxlflash could revert to a model that does not require an embedded fops. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Daniel Axtens <dja@axtens.net> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Fix to double the delay each timeManoj Kumar
The operator used to double the master context response delay is incorrect and does not result in delay doubling. To fix, use a left shift instead of the XOR operator. Reported-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Fix to prevent stale AFU RRQMatthew R. Ochs
Following an adapter reset, the AFU RRQ that resides in host memory holds stale data. This can lead to a condition where the RRQ interrupt handler tries to process stale entries and/or endlessly loops due to an out of sync generation bit. To fix, the AFU RRQ in host memory needs to be cleared after each reset. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Daniel Axtens <dja@axtens.net> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Correct spelling, grammar, and alignment mistakesMatthew R. Ochs
There are several spelling and grammar mistakes throughout the driver. Additionally there are a handful of places where there are extra lines and unnecessary variables/statements. These are a nuisance and pollute the driver. Fix spelling and grammar issues. Update some comments for clarity and consistency. Remove extra lines and a few unneeded variables/statements. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Fix MMIO and endianness errorsMatthew R. Ochs
Sparse uncovered several errors with MMIO operations (accessing directly) and handling endianness. These can cause issues when running in different environments. Introduce __iomem and proper endianness tags/swaps where appropriate to make driver sparse clean. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Fix function prolog parameters and return codesMatthew R. Ochs
Several function prologs have incorrect parameter names and return code descriptions. This can lead to confusion when reviewing the source and creates inaccurate documentation. To remedy, update the function prologs to properly reflect parameter names and return codes. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Remove unnecessary scsi_block_requestsMatthew R. Ochs
The host reset handler is called with I/O already blocked, thus there is no need to explicitly block and unblock I/O in the handler. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Correct behavior in device reset handler following EEHMatthew R. Ochs
When the device reset handler is entered while a reset operation is taking place, the handler exits without actually sending a reset (TMF) to the targeted device. This behavior is incorrect as the device is not reset. Further complicating matters is the fact that a success is returned even when the TMF was not sent. To fix, the state is rechecked after coming out of the reset state. When the state is normal, a TMF will be sent out. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Fix to prevent workq from accessing freed memoryMatthew R. Ochs
The workq can process work in parallel with a remove event, leading to a condition where the workq handler can access freed memory. To remedy, the workq should be terminated prior to freeing memory. Move the termination call earlier in remove and use cancel_work_sync() instead of flush_work() as there is not a need to process any scheduled work when shutting down. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Correct usage of scsi_host_put()Matthew R. Ochs
Currently, scsi_host_put() is being called prematurely in the remove path and is missing entirely in an error cleanup path. The former can lead to memory being freed too early with subsequent access potentially corrupting data whilst the former would result in a memory leak. Move the usage on remove to be the last cleanup action taken and introduce a call to scsi_host_put() in the one initialization error path that does not use remove to cleanup. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Fix AFU version access/storage and add checkMatthew R. Ochs
The AFU version is stored as a non-terminated string of bytes within a 64-bit little-endian register. Presently the value is read directly (no MMIO accessor) and is stored in a buffer that is not big enough to contain a NULL terminator. Additionally the version obtained is not evaluated against a known value to prevent usage with unsupported AFUs. All of these deficiencies can lead to a variety of problems. To remedy, use the correct MMIO accessor to read the version value into a null-terminated buffer and add a check to prevent an incompatible AFU from being used with this driver. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Daniel Axtens <dja@axtens.net> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Remove dual port online dependencyMatthew R. Ochs
At present, both ports must be online for the device to configure properly. Remove this dependency and the unnecessary internal LUN override logic as well. Additionally, as a refactoring measure, change the return code variable name to match that used throughout the driver. With this change, the card will be able to configure even when the link is down. At some later point when the link is transitioned to 'up', a link state change interrupt will trigger the port configuration. Note that despite its void-like behavior, the function was left with a return code for right now in case its behavior needs to be altered again in the near future based on testing. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Daniel Axtens <dja@axtens.net> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Fix async interrupt bypass logicMatthew R. Ochs
A bug was introduced earlier in the development cycle when cleaning up logic statements. Instead of skipping bits that are not set, set bits are skipped, causing async interrupts to not be handled correctly. To fix, simply add back in the proper evaluation for an unset bit. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Fix host link up event handlingMatthew R. Ochs
Following a link up event, the LUNs available to the host may have changed. Without rescanning the host, the LUN topology is unknown to the user. In such a state, the user would be unable to locate provisioned resources. To remedy, the host should be rescanned after a link up event. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Fix location of setting residMatthew R. Ochs
The resid is incorrectly set which can lead to unnecessary retry attempts by the stack. This is due to resid _always_ being set using a value returned from the adapter. Instead, the value should only be interpreted and set when in an underrun scenario. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Fix to avoid stall while waiting on TMFMatthew R. Ochs
Borrowing the TMF waitq's spinlock causes a stall condition when waiting for the TMF to complete. To remedy, introduce our own spin lock to serialize TMF and use the appropriate wait services. Also add a timeout while waiting for a TMF completion. When a TMF times out, report back a failure such that a bigger hammer reset can occur. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Fix to avoid spamming the kernel logMatthew R. Ochs
During run-time the driver can be very chatty and spam the system kernel log. Various print statements can be limited and/or moved to development-only mode. Additionally, numerous prints can be converted to trace the corresponding device. Lastly, one spelling correction was made: 'entra' to 'extra'. The following changes were made: - pr_debug to pr_devel - pr_debug to pr_debug_ratelimited - pr_err to dev_err - pr_debug to dev_dbg Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Refine host/device attributesMatthew R. Ochs
Implement the following suggestions and add two new attributes to allow for debugging the port LUN table. - use scnprintf() instead of snprintf() - use DEVICE_ATTR_RO and DEVICE_ATTR_RW Suggested-by: Shane Seymour <shane.seymour@hp.com> Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Make functions staticMatthew R. Ochs
Found during code inspection, that the following functions are not being used outside of the file where they are defined. Make them static. int cxlflash_send_cmd(struct afu *, struct afu_cmd *); void cxlflash_wait_resp(struct afu *, struct afu_cmd *); int cxlflash_afu_reset(struct cxlflash_cfg *); struct afu_cmd *cxlflash_cmd_checkout(struct afu *); void cxlflash_cmd_checkin(struct afu_cmd *); void init_pcr(struct cxlflash_cfg *); int init_global(struct cxlflash_cfg *); Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Correct naming of limbo state and waitqMatthew R. Ochs
Limbo is not an accurate representation of this state and is also not consistent with the terminology that other drivers use to represent this concept. Rename the state and and its associated waitq to 'reset'. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Daniel Axtens <dja@axtens.net> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-10-30cxlflash: Fix to avoid CXL services during EEHMatthew R. Ochs
During an EEH freeze event, certain CXL services should not be called until after the hardware reset has taken place. Doing so can result in unnecessary failures and possibly cause other ill effects by triggering hardware accesses. This translates to a requirement to quiesce all threads that may potentially use CXL runtime service during this window. In particular, multiple ioctls make use of the CXL services when acting on contexts on behalf of the user. Thus, it is essential to 'drain' running ioctls _before_ proceeding with handling the EEH freeze event. Create the ability to drain ioctls by wrapping the ioctl handler call in a read semaphore and then implementing a small routine that obtains the write semaphore, effectively creating a wait point for all currently executing ioctls. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reviewed-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Daniel Axtens <dja@axtens.net> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-08-26cxlflash: Remove unused variable from queuecommandMatthew R. Ochs
The queuecommand routine has a local dev pointer used for the dev_* prints. The two prints that currently exist are tucked under a debug define and thus can be left out. Use the actual location instead of a local to avoid this warning. This patch is intended to be applied after the "CXL Flash Error Recovery and Superpipe" series. Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com> Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-08-26cxlflash: shift wrapping bug in afu_link_reset()Dan Carpenter
"port_sel" is a u64 so the shifting should also be a 64 bit shift. Fixes: c21e0bbfc485 ('cxlflash: Base support for IBM CXL Flash Adapter') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>