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Author SHA1 Message Date
Matthew R. Ochs c4a11827b7 scsi: cxlflash: Fix context reference tracking on detach 
Commit 888baf069f ("scsi: cxlflash: Add kref to context") introduced a
kref to the context. In particular, the detach routine was updated to
use the kref services for managing the removal and destruction of a
context.

As part of this change, the tracking mechanism internal to the detach
handler was refactored. This introduced a bug that can cause the
tracking state to be lost. This can lead to a situation where exclusive
access to a context is prematurely [and unknowingly] relinquished for
the executing thread.

To remedy, only update the tracking state when the kref operation
indicates the context was removed.

Fixes: 888baf069f ("scsi: cxlflash: Add kref to context")
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>
 2016-09-14 12:47:42 -04:00
Matthew R. Ochs f80132613d scsi: cxlflash: Refactor WWPN setup 
Commit 964497b3bf ("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>
 2016-09-14 12:47:03 -04:00
Matthew R. Ochs 05dab43230 scsi: cxlflash: Improve EEH recovery time 
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>
 2016-09-14 12:46:20 -04:00
Matthew R. Ochs 1d3324c382 scsi: cxlflash: Fix to avoid EEH and host reset collisions 
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>
 2016-09-14 12:45:06 -04:00
Uma Krishnan babf985d1e scsi: cxlflash: Remove the device cleanly in the system shutdown path 
Commit 704c4b0ddc ("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: 704c4b0ddc ("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>
 2016-09-09 07:34:58 -04:00
Uma Krishnan bbbfae962b scsi: cxlflash: Scan host only after the port is ready for I/O 
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>
 2016-09-09 07:34:18 -04:00
Matthew R. Ochs de9f0b0cbb scsi: cxlflash: Remove adapter file descriptor cache 
The adapter file descriptor was previously cached within the kernel for
a given context in order to support performing a close on behalf of an
application. This is no longer needed as applications are now required
to perform a close on the adapter file descriptor.

Inspired-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Acked-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
 2016-08-23 22:23:52 -04:00
Matthew R. Ochs cd34af40a0 scsi: cxlflash: Transition to application close model 
Caching the adapter file descriptor and performing a close on behalf of
an application is a poor design. This is due to the fact that once a
file descriptor in installed, it is free to be altered without the
knowledge of the cxlflash driver. This can lead to inconsistencies
between the application and kernel. Furthermore, the nature of the
former design is more exploitable and thus should be abandoned.

To support applications performing a close on the adapter file that is
associated with a context, a new flag is introduced to the user API to
indicate to applications that they are responsible for the close
following the cleanup (detach) of a context. The documentation is also
updated to reflect this change in behavior.

Inspired-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Acked-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
 2016-08-23 22:23:41 -04:00
Matthew R. Ochs 888baf069f scsi: cxlflash: Add kref to context 
Currently, context user references are tracked via the list of LUNs that
have attached to the context. While convenient, this is not intuitive
without a deep study of the code and is inconsistent with the existing
reference tracking patterns within the kernel. This design choice can
lead to future bug injection.

To improve code comprehension and better protect against future bugs,
add explicit reference counting to contexts and migrate the context
removal code to the kref release handler.

Inspired-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Acked-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
 2016-08-18 22:41:36 -04:00
Matthew R. Ochs 44ef38f9a2 scsi: cxlflash: Cache owning adapter within context 
The context removal routine requires access to the owning adapter
structure to reset the context within the AFU as part of the tear down
sequence. In order to support kref adoption, the owning adapter must be
accessible from the release handler. As the kref framework only provides
the kref reference as the sole parameter, another means is needed to
derive the owning adapter.

As a remedy, the owning adapter reference is saved off within the
context during initialization.

Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Acked-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
 2016-08-18 22:40:27 -04:00
Matthew R. Ochs 41b99e1a30 scsi: cxlflash: Avoid mutex when destroying context 
Context information structures are protected by a mutex that is held
when accessing/manipulating the context. When the code that manages
these structures was authored, a decision was made to include taking the
mutex as part of the allocation/initialization sequence and also handle
the scenario where the mutex was already held when freeing the context.

While not a problem outright, this design decision has been deemed as
too flexible and the code should be made more rigid to avoid future
bugs.  In addition, further review of the code yields that the existing
mutex manipulations in both of these context management paths are
superfluous.

This commit removes the obtaining of the context mutex in the context
initialization routine and assumes the mutex is not held in the context
free path.

Inspired-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Acked-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
 2016-08-18 22:39:45 -04:00
Linus Torvalds 0603006b45 SCSI misc on 20160805 
This is seven basic fixes (plus one MAINTAINER update) which came in
 close to the merge window.
 
 Signed-off-by: James Bottomley <jejb@linux.vnet.ibm.com>
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Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI fixes from James Bottomley:
 "This is seven basic fixes (plus one MAINTAINER update) which came in
  close to the merge window"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  ipr: Fix error return code in ipr_probe_ioa()
  fcoe: add missing destroy_workqueue() on error in fcoe_init()
  lpfc: Fix possible NULL pointer dereference
  fcoe: Use default VLAN for FIP VLAN discovery
  ipr: Wait to do async scan until scsi host is initialized
  MAINTAINERS: Update cxlflash maintainers
  cxlflash: Verify problem state area is mapped before notifying shutdown
  lpfc: fix oops in lpfc_sli4_scmd_to_wqidx_distr() from lpfc_send_taskmgmt()
 2016-08-05 23:47:27 -04:00
Linus Torvalds bad60e6f25 powerpc updates for 4.8 # 1 
Highlights:
  - PowerNV PCI hotplug support.
  - Lots more Power9 support.
  - eBPF JIT support on ppc64le.
  - Lots of cxl updates.
  - Boot code consolidation.
 
 Bug fixes:
  - Fix spin_unlock_wait() from Boqun Feng
  - Fix stack pointer corruption in __tm_recheckpoint() from Michael Neuling
  - Fix multiple bugs in memory_hotplug_max() from Bharata B Rao
  - mm: Ensure "special" zones are empty from Oliver O'Halloran
  - ftrace: Separate the heuristics for checking call sites from Michael Ellerman
  - modules: Never restore r2 for a mprofile-kernel style mcount() call from Michael Ellerman
  - Fix endianness when reading TCEs from Alexey Kardashevskiy
  - start rtasd before PCI probing from Greg Kurz
  - PCI: rpaphp: Fix slot registration for multiple slots under a PHB from Tyrel Datwyler
  - powerpc/mm: Add memory barrier in __hugepte_alloc() from Sukadev Bhattiprolu
 
 Cleanups & fixes:
  - Drop support for MPIC in pseries from Rashmica Gupta
  - Define and use PPC64_ELF_ABI_v2/v1 from Michael Ellerman
  - Remove unused symbols in asm-offsets.c from Rashmica Gupta
  - Fix SRIOV not building without EEH enabled from Russell Currey
  - Remove kretprobe_trampoline_holder. from Thiago Jung Bauermann
  - Reduce log level of PCI I/O space warning from Benjamin Herrenschmidt
  - Add array bounds checking to crash_shutdown_handlers from Suraj Jitindar Singh
  - Avoid -maltivec when using clang integrated assembler from Anton Blanchard
  - Fix array overrun in ppc_rtas() syscall from Andrew Donnellan
  - Fix error return value in cmm_mem_going_offline() from Rasmus Villemoes
  - export cpu_to_core_id() from Mauricio Faria de Oliveira
  - Remove old symbols from defconfigs from Andrew Donnellan
  - Update obsolete comments in setup_32.c about entry conditions from Benjamin Herrenschmidt
  - Add comment explaining the purpose of setup_kdump_trampoline() from Benjamin Herrenschmidt
  - Merge the RELOCATABLE config entries for ppc32 and ppc64 from Kevin Hao
  - Remove RELOCATABLE_PPC32 from Kevin Hao
  - Fix .long's in tlb-radix.c to more meaningful from Balbir Singh
 
 Minor cleanups & fixes:
  - Andrew Donnellan, Anna-Maria Gleixner, Anton Blanchard, Benjamin
    Herrenschmidt, Bharata B Rao, Christophe Leroy, Colin Ian King, Geliang
    Tang, Greg Kurz, Madhavan Srinivasan, Michael Ellerman, Michael Ellerman,
    Stephen Rothwell, Stewart Smith.
 
 Freescale updates from Scott:
  - "Highlights include more 8xx optimizations, device tree updates,
    and MVME7100 support."
 
 PowerNV PCI hotplug from Gavin Shan:
  - PCI: Add pcibios_setup_bridge()
  - Override pcibios_setup_bridge()
  - Remove PCI_RESET_DELAY_US
  - Move pnv_pci_ioda_setup_opal_tce_kill() around
  - Increase PE# capacity
  - Allocate PE# in reverse order
  - Create PEs in pcibios_setup_bridge()
  - Setup PE for root bus
  - Extend PCI bridge resources
  - Make pnv_ioda_deconfigure_pe() visible
  - Dynamically release PE
  - Update bridge windows on PCI plug
  - Delay populating pdn
  - Support PCI slot ID
  - Use PCI slot reset infrastructure
  - Introduce pnv_pci_get_slot_id()
  - Functions to get/set PCI slot state
  - PCI/hotplug: PowerPC PowerNV PCI hotplug driver
  - Print correct PHB type names
 
 Power9 idle support from Shreyas B. Prabhu:
  - set power_save func after the idle states are initialized
  - Use PNV_THREAD_WINKLE macro while requesting for winkle
  - make hypervisor state restore a function
  - Rename idle_power7.S to idle_book3s.S
  - Rename reusable idle functions to hardware agnostic names
  - Make pnv_powersave_common more generic
  - abstraction for saving SPRs before entering deep idle states
  - Add platform support for stop instruction
  - cpuidle/powernv: Use CPUIDLE_STATE_MAX instead of MAX_POWERNV_IDLE_STATES
  - cpuidle/powernv: cleanup cpuidle-powernv.c
  - cpuidle/powernv: Add support for POWER ISA v3 idle states
  - Use deepest stop state when cpu is offlined
 
 Power9 PMU from Madhavan Srinivasan:
  - factor out power8 pmu macros and defines
  - factor out power8 pmu functions
  - factor out power8 __init_pmu code
  - Add power9 event list macros for generic and cache events
  - Power9 PMU support
  - Export Power9 generic and cache events to sysfs
 
 Power9 preliminary interrupt & PCI support from Benjamin Herrenschmidt:
  - Add XICS emulation APIs
  - Move a few exception common handlers to make room
  - Add support for HV virtualization interrupts
  - Add mechanism to force a replay of interrupts
  - Add ICP OPAL backend
  - Discover IODA3 PHBs
  - pci: Remove obsolete SW invalidate
  - opal: Add real mode call wrappers
  - Rename TCE invalidation calls
  - Remove SWINV constants and obsolete TCE code
  - Rework accessing the TCE invalidate register
  - Fallback to OPAL for TCE invalidations
  - Use the device-tree to get available range of M64's
  - Check status of a PHB before using it
  - pci: Don't try to allocate resources that will be reassigned
 
 Other Power9:
  - Send SIGBUS on unaligned copy and paste from Chris Smart
  - Large Decrementer support from Oliver O'Halloran
  - Load Monitor Register Support from Jack Miller
 
 Performance improvements from Anton Blanchard:
  - Avoid load hit store in __giveup_fpu() and __giveup_altivec()
  - Avoid load hit store in setup_sigcontext()
  - Remove assembly versions of strcpy, strcat, strlen and strcmp
  - Align hot loops of some string functions
 
 eBPF JIT from Naveen N. Rao:
  - Fix/enhance 32-bit Load Immediate implementation
  - Optimize 64-bit Immediate loads
  - Introduce rotate immediate instructions
  - A few cleanups
  - Isolate classic BPF JIT specifics into a separate header
  - Implement JIT compiler for extended BPF
 
 Operator Panel driver from Suraj Jitindar Singh:
  - devicetree/bindings: Add binding for operator panel on FSP machines
  - Add inline function to get rc from an ASYNC_COMP opal_msg
  - Add driver for operator panel on FSP machines
 
 Sparse fixes from Daniel Axtens:
  - make some things static
  - Introduce asm-prototypes.h
  - Include headers containing prototypes
  - Use #ifdef __BIG_ENDIAN__ #else for REG_BYTE
  - kvm: Clarify __user annotations
  - Pass endianness to sparse
  - Make ppc_md.{halt, restart} __noreturn
 
 MM fixes & cleanups from Aneesh Kumar K.V:
  - radix: Update LPCR HR bit as per ISA
  - use _raw variant of page table accessors
  - Compile out radix related functions if RADIX_MMU is disabled
  - Clear top 16 bits of va only on older cpus
  - Print formation regarding the the MMU mode
  - hash: Update SDR1 size encoding as documented in ISA 3.0
  - radix: Update PID switch sequence
  - radix: Update machine call back to support new HCALL.
  - radix: Add LPID based tlb flush helpers
  - radix: Add a kernel command line to disable radix
  - Cleanup LPCR defines
 
 Boot code consolidation from Benjamin Herrenschmidt:
  - Move epapr_paravirt_early_init() to early_init_devtree()
  - cell: Don't use flat device-tree after boot
  - ge_imp3a: Don't use the flat device-tree after boot
  - mpc85xx_ds: Don't use the flat device-tree after boot
  - mpc85xx_rdb: Don't use the flat device-tree after boot
  - Don't test for machine type in rtas_initialize()
  - Don't test for machine type in smp_setup_cpu_maps()
  - dt: Add of_device_compatible_match()
  - Factor do_feature_fixup calls
  - Move 64-bit feature fixup earlier
  - Move 64-bit memory reserves to setup_arch()
  - Use a cachable DART
  - Move FW feature probing out of pseries probe()
  - Put exception configuration in a common place
  - Remove early allocation of the SMU command buffer
  - Move MMU backend selection out of platform code
  - pasemi: Remove IOBMAP allocation from platform probe()
  - mm/hash: Don't use machine_is() early during boot
  - Don't test for machine type to detect HEA special case
  - pmac: Remove spurrious machine type test
  - Move hash table ops to a separate structure
  - Ensure that ppc_md is empty before probing for machine type
  - Move 64-bit probe_machine() to later in the boot process
  - Move 32-bit probe() machine to later in the boot process
  - Get rid of ppc_md.init_early()
  - Move the boot time info banner to a separate function
  - Move setting of {i,d}cache_bsize to initialize_cache_info()
  - Move the content of setup_system() to setup_arch()
  - Move cache info inits to a separate function
  - Re-order the call to smp_setup_cpu_maps()
  - Re-order setup_panic()
  - Make a few boot functions __init
  - Merge 32-bit and 64-bit setup_arch()
 
 Other new features:
  - tty/hvc: Use IRQF_SHARED for OPAL hvc consoles from Sam Mendoza-Jonas
  - tty/hvc: Use opal irqchip interface if available from Sam Mendoza-Jonas
  - powerpc: Add module autoloading based on CPU features from Alastair D'Silva
  - crypto: vmx - Convert to CPU feature based module autoloading from Alastair D'Silva
  - Wake up kopald polling thread before waiting for events from Benjamin Herrenschmidt
  - xmon: Dump ISA 2.06 SPRs from Michael Ellerman
  - xmon: Dump ISA 2.07 SPRs from Michael Ellerman
  - Add a parameter to disable 1TB segs from Oliver O'Halloran
  - powerpc/boot: Add OPAL console to epapr wrappers from Oliver O'Halloran
  - Assign fixed PHB number based on device-tree properties from Guilherme G. Piccoli
  - pseries: Add pseries hotplug workqueue from John Allen
  - pseries: Add support for hotplug interrupt source from John Allen
  - pseries: Use kernel hotplug queue for PowerVM hotplug events from John Allen
  - pseries: Move property cloning into its own routine from Nathan Fontenot
  - pseries: Dynamic add entires to associativity lookup array from Nathan Fontenot
  - pseries: Auto-online hotplugged memory from Nathan Fontenot
  - pseries: Remove call to memblock_add() from Nathan Fontenot
 
 cxl:
  - Add set and get private data to context struct from Michael Neuling
  - make base more explicitly non-modular from Paul Gortmaker
  - Use for_each_compatible_node() macro from Wei Yongjun
  - Frederic Barrat
    - Abstract the differences between the PSL and XSL
    - Make vPHB device node match adapter's
  - Philippe Bergheaud
    - Add mechanism for delivering AFU driver specific events
    - Ignore CAPI adapters misplaced in switched slots
    - Refine slice error debug messages
  - Andrew Donnellan
    - static-ify variables to fix sparse warnings
    - PCI/hotplug: pnv_php: export symbols and move struct types needed by cxl
    - PCI/hotplug: pnv_php: handle OPAL_PCI_SLOT_OFFLINE power state
    - Add cxl_check_and_switch_mode() API to switch bi-modal cards
    - remove dead Kconfig options
    - fix potential NULL dereference in free_adapter()
  - Ian Munsie
    - Update process element after allocating interrupts
    - Add support for CAPP DMA mode
    - Fix allowing bogus AFU descriptors with 0 maximum processes
    - Fix allocating a minimum of 2 pages for the SPA
    - Fix bug where AFU disable operation had no effect
    - Workaround XSL bug that does not clear the RA bit after a reset
    - Fix NULL pointer dereference on kernel contexts with no AFU interrupts
    - powerpc/powernv: Split cxl code out into a separate file
    - Add cxl_slot_is_supported API
    - Enable bus mastering for devices using CAPP DMA mode
    - Move cxl_afu_get / cxl_afu_put to base
    - Allow a default context to be associated with an external pci_dev
    - Do not create vPHB if there are no AFU configuration records
    - powerpc/powernv: Add support for the cxl kernel api on the real phb
    - Add support for using the kernel API with a real PHB
    - Add kernel APIs to get & set the max irqs per context
    - Add preliminary workaround for CX4 interrupt limitation
    - Add support for interrupts on the Mellanox CX4
    - Workaround PE=0 hardware limitation in Mellanox CX4
    - powerpc/powernv: Fix pci-cxl.c build when CONFIG_MODULES=n
 
 selftests:
  - Test unaligned copy and paste from Chris Smart
  - Load Monitor Register Tests from Jack Miller
  - Cyril Bur
    - exec() with suspended transaction
    - Use signed long to read perf_event_paranoid
    - Fix usage message in context_switch
    - Fix generation of vector instructions/types in context_switch
  - Michael Ellerman
    - Use "Delta" rather than "Error" in normal output
    - Import Anton's mmap & futex micro benchmarks
    - Add a test for PROT_SAO
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Merge tag 'powerpc-4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Highlights:
   - PowerNV PCI hotplug support.
   - Lots more Power9 support.
   - eBPF JIT support on ppc64le.
   - Lots of cxl updates.
   - Boot code consolidation.

  Bug fixes:
   - Fix spin_unlock_wait() from Boqun Feng
   - Fix stack pointer corruption in __tm_recheckpoint() from Michael
     Neuling
   - Fix multiple bugs in memory_hotplug_max() from Bharata B Rao
   - mm: Ensure "special" zones are empty from Oliver O'Halloran
   - ftrace: Separate the heuristics for checking call sites from
     Michael Ellerman
   - modules: Never restore r2 for a mprofile-kernel style mcount() call
     from Michael Ellerman
   - Fix endianness when reading TCEs from Alexey Kardashevskiy
   - start rtasd before PCI probing from Greg Kurz
   - PCI: rpaphp: Fix slot registration for multiple slots under a PHB
     from Tyrel Datwyler
   - powerpc/mm: Add memory barrier in __hugepte_alloc() from Sukadev
     Bhattiprolu

  Cleanups & fixes:
   - Drop support for MPIC in pseries from Rashmica Gupta
   - Define and use PPC64_ELF_ABI_v2/v1 from Michael Ellerman
   - Remove unused symbols in asm-offsets.c from Rashmica Gupta
   - Fix SRIOV not building without EEH enabled from Russell Currey
   - Remove kretprobe_trampoline_holder from Thiago Jung Bauermann
   - Reduce log level of PCI I/O space warning from Benjamin
     Herrenschmidt
   - Add array bounds checking to crash_shutdown_handlers from Suraj
     Jitindar Singh
   - Avoid -maltivec when using clang integrated assembler from Anton
     Blanchard
   - Fix array overrun in ppc_rtas() syscall from Andrew Donnellan
   - Fix error return value in cmm_mem_going_offline() from Rasmus
     Villemoes
   - export cpu_to_core_id() from Mauricio Faria de Oliveira
   - Remove old symbols from defconfigs from Andrew Donnellan
   - Update obsolete comments in setup_32.c about entry conditions from
     Benjamin Herrenschmidt
   - Add comment explaining the purpose of setup_kdump_trampoline() from
     Benjamin Herrenschmidt
   - Merge the RELOCATABLE config entries for ppc32 and ppc64 from Kevin
     Hao
   - Remove RELOCATABLE_PPC32 from Kevin Hao
   - Fix .long's in tlb-radix.c to more meaningful from Balbir Singh

  Minor cleanups & fixes:
   - Andrew Donnellan, Anna-Maria Gleixner, Anton Blanchard, Benjamin
     Herrenschmidt, Bharata B Rao, Christophe Leroy, Colin Ian King,
     Geliang Tang, Greg Kurz, Madhavan Srinivasan, Michael Ellerman,
     Michael Ellerman, Stephen Rothwell, Stewart Smith.

  Freescale updates from Scott:
   - "Highlights include more 8xx optimizations, device tree updates,
     and MVME7100 support."

  PowerNV PCI hotplug from Gavin Shan:
   - PCI: Add pcibios_setup_bridge()
   - Override pcibios_setup_bridge()
   - Remove PCI_RESET_DELAY_US
   - Move pnv_pci_ioda_setup_opal_tce_kill() around
   - Increase PE# capacity
   - Allocate PE# in reverse order
   - Create PEs in pcibios_setup_bridge()
   - Setup PE for root bus
   - Extend PCI bridge resources
   - Make pnv_ioda_deconfigure_pe() visible
   - Dynamically release PE
   - Update bridge windows on PCI plug
   - Delay populating pdn
   - Support PCI slot ID
   - Use PCI slot reset infrastructure
   - Introduce pnv_pci_get_slot_id()
   - Functions to get/set PCI slot state
   - PCI/hotplug: PowerPC PowerNV PCI hotplug driver
   - Print correct PHB type names

  Power9 idle support from Shreyas B. Prabhu:
   - set power_save func after the idle states are initialized
   - Use PNV_THREAD_WINKLE macro while requesting for winkle
   - make hypervisor state restore a function
   - Rename idle_power7.S to idle_book3s.S
   - Rename reusable idle functions to hardware agnostic names
   - Make pnv_powersave_common more generic
   - abstraction for saving SPRs before entering deep idle states
   - Add platform support for stop instruction
   - cpuidle/powernv: Use CPUIDLE_STATE_MAX instead of MAX_POWERNV_IDLE_STATES
   - cpuidle/powernv: cleanup cpuidle-powernv.c
   - cpuidle/powernv: Add support for POWER ISA v3 idle states
   - Use deepest stop state when cpu is offlined

  Power9 PMU from Madhavan Srinivasan:
   - factor out power8 pmu macros and defines
   - factor out power8 pmu functions
   - factor out power8 __init_pmu code
   - Add power9 event list macros for generic and cache events
   - Power9 PMU support
   - Export Power9 generic and cache events to sysfs

  Power9 preliminary interrupt & PCI support from Benjamin Herrenschmidt:
   - Add XICS emulation APIs
   - Move a few exception common handlers to make room
   - Add support for HV virtualization interrupts
   - Add mechanism to force a replay of interrupts
   - Add ICP OPAL backend
   - Discover IODA3 PHBs
   - pci: Remove obsolete SW invalidate
   - opal: Add real mode call wrappers
   - Rename TCE invalidation calls
   - Remove SWINV constants and obsolete TCE code
   - Rework accessing the TCE invalidate register
   - Fallback to OPAL for TCE invalidations
   - Use the device-tree to get available range of M64's
   - Check status of a PHB before using it
   - pci: Don't try to allocate resources that will be reassigned

  Other Power9:
   - Send SIGBUS on unaligned copy and paste from Chris Smart
   - Large Decrementer support from Oliver O'Halloran
   - Load Monitor Register Support from Jack Miller

  Performance improvements from Anton Blanchard:
   - Avoid load hit store in __giveup_fpu() and __giveup_altivec()
   - Avoid load hit store in setup_sigcontext()
   - Remove assembly versions of strcpy, strcat, strlen and strcmp
   - Align hot loops of some string functions

  eBPF JIT from Naveen N. Rao:
   - Fix/enhance 32-bit Load Immediate implementation
   - Optimize 64-bit Immediate loads
   - Introduce rotate immediate instructions
   - A few cleanups
   - Isolate classic BPF JIT specifics into a separate header
   - Implement JIT compiler for extended BPF

  Operator Panel driver from Suraj Jitindar Singh:
   - devicetree/bindings: Add binding for operator panel on FSP machines
   - Add inline function to get rc from an ASYNC_COMP opal_msg
   - Add driver for operator panel on FSP machines

  Sparse fixes from Daniel Axtens:
   - make some things static
   - Introduce asm-prototypes.h
   - Include headers containing prototypes
   - Use #ifdef __BIG_ENDIAN__ #else for REG_BYTE
   - kvm: Clarify __user annotations
   - Pass endianness to sparse
   - Make ppc_md.{halt, restart} __noreturn

  MM fixes & cleanups from Aneesh Kumar K.V:
   - radix: Update LPCR HR bit as per ISA
   - use _raw variant of page table accessors
   - Compile out radix related functions if RADIX_MMU is disabled
   - Clear top 16 bits of va only on older cpus
   - Print formation regarding the the MMU mode
   - hash: Update SDR1 size encoding as documented in ISA 3.0
   - radix: Update PID switch sequence
   - radix: Update machine call back to support new HCALL.
   - radix: Add LPID based tlb flush helpers
   - radix: Add a kernel command line to disable radix
   - Cleanup LPCR defines

  Boot code consolidation from Benjamin Herrenschmidt:
   - Move epapr_paravirt_early_init() to early_init_devtree()
   - cell: Don't use flat device-tree after boot
   - ge_imp3a: Don't use the flat device-tree after boot
   - mpc85xx_ds: Don't use the flat device-tree after boot
   - mpc85xx_rdb: Don't use the flat device-tree after boot
   - Don't test for machine type in rtas_initialize()
   - Don't test for machine type in smp_setup_cpu_maps()
   - dt: Add of_device_compatible_match()
   - Factor do_feature_fixup calls
   - Move 64-bit feature fixup earlier
   - Move 64-bit memory reserves to setup_arch()
   - Use a cachable DART
   - Move FW feature probing out of pseries probe()
   - Put exception configuration in a common place
   - Remove early allocation of the SMU command buffer
   - Move MMU backend selection out of platform code
   - pasemi: Remove IOBMAP allocation from platform probe()
   - mm/hash: Don't use machine_is() early during boot
   - Don't test for machine type to detect HEA special case
   - pmac: Remove spurrious machine type test
   - Move hash table ops to a separate structure
   - Ensure that ppc_md is empty before probing for machine type
   - Move 64-bit probe_machine() to later in the boot process
   - Move 32-bit probe() machine to later in the boot process
   - Get rid of ppc_md.init_early()
   - Move the boot time info banner to a separate function
   - Move setting of {i,d}cache_bsize to initialize_cache_info()
   - Move the content of setup_system() to setup_arch()
   - Move cache info inits to a separate function
   - Re-order the call to smp_setup_cpu_maps()
   - Re-order setup_panic()
   - Make a few boot functions __init
   - Merge 32-bit and 64-bit setup_arch()

  Other new features:
   - tty/hvc: Use IRQF_SHARED for OPAL hvc consoles from Sam Mendoza-Jonas
   - tty/hvc: Use opal irqchip interface if available from Sam Mendoza-Jonas
   - powerpc: Add module autoloading based on CPU features from Alastair D'Silva
   - crypto: vmx - Convert to CPU feature based module autoloading from Alastair D'Silva
   - Wake up kopald polling thread before waiting for events from Benjamin Herrenschmidt
   - xmon: Dump ISA 2.06 SPRs from Michael Ellerman
   - xmon: Dump ISA 2.07 SPRs from Michael Ellerman
   - Add a parameter to disable 1TB segs from Oliver O'Halloran
   - powerpc/boot: Add OPAL console to epapr wrappers from Oliver O'Halloran
   - Assign fixed PHB number based on device-tree properties from Guilherme G. Piccoli
   - pseries: Add pseries hotplug workqueue from John Allen
   - pseries: Add support for hotplug interrupt source from John Allen
   - pseries: Use kernel hotplug queue for PowerVM hotplug events from John Allen
   - pseries: Move property cloning into its own routine from Nathan Fontenot
   - pseries: Dynamic add entires to associativity lookup array from Nathan Fontenot
   - pseries: Auto-online hotplugged memory from Nathan Fontenot
   - pseries: Remove call to memblock_add() from Nathan Fontenot

  cxl:
   - Add set and get private data to context struct from Michael Neuling
   - make base more explicitly non-modular from Paul Gortmaker
   - Use for_each_compatible_node() macro from Wei Yongjun
   - Frederic Barrat
   - Abstract the differences between the PSL and XSL
   - Make vPHB device node match adapter's
   - Philippe Bergheaud
   - Add mechanism for delivering AFU driver specific events
   - Ignore CAPI adapters misplaced in switched slots
   - Refine slice error debug messages
   - Andrew Donnellan
   - static-ify variables to fix sparse warnings
   - PCI/hotplug: pnv_php: export symbols and move struct types needed by cxl
   - PCI/hotplug: pnv_php: handle OPAL_PCI_SLOT_OFFLINE power state
   - Add cxl_check_and_switch_mode() API to switch bi-modal cards
   - remove dead Kconfig options
   - fix potential NULL dereference in free_adapter()
   - Ian Munsie
   - Update process element after allocating interrupts
   - Add support for CAPP DMA mode
   - Fix allowing bogus AFU descriptors with 0 maximum processes
   - Fix allocating a minimum of 2 pages for the SPA
   - Fix bug where AFU disable operation had no effect
   - Workaround XSL bug that does not clear the RA bit after a reset
   - Fix NULL pointer dereference on kernel contexts with no AFU interrupts
   - powerpc/powernv: Split cxl code out into a separate file
   - Add cxl_slot_is_supported API
   - Enable bus mastering for devices using CAPP DMA mode
   - Move cxl_afu_get / cxl_afu_put to base
   - Allow a default context to be associated with an external pci_dev
   - Do not create vPHB if there are no AFU configuration records
   - powerpc/powernv: Add support for the cxl kernel api on the real phb
   - Add support for using the kernel API with a real PHB
   - Add kernel APIs to get & set the max irqs per context
   - Add preliminary workaround for CX4 interrupt limitation
   - Add support for interrupts on the Mellanox CX4
   - Workaround PE=0 hardware limitation in Mellanox CX4
   - powerpc/powernv: Fix pci-cxl.c build when CONFIG_MODULES=n

  selftests:
   - Test unaligned copy and paste from Chris Smart
   - Load Monitor Register Tests from Jack Miller
   - Cyril Bur
   - exec() with suspended transaction
   - Use signed long to read perf_event_paranoid
   - Fix usage message in context_switch
   - Fix generation of vector instructions/types in context_switch
   - Michael Ellerman
   - Use "Delta" rather than "Error" in normal output
   - Import Anton's mmap & futex micro benchmarks
   - Add a test for PROT_SAO"

* tag 'powerpc-4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (263 commits)
  powerpc/mm: Parenthesise IS_ENABLED() in if condition
  tty/hvc: Use opal irqchip interface if available
  tty/hvc: Use IRQF_SHARED for OPAL hvc consoles
  selftests/powerpc: exec() with suspended transaction
  powerpc: Improve comment explaining why we modify VRSAVE
  powerpc/mm: Drop unused externs for hpte_init_beat[_v3]()
  powerpc/mm: Rename hpte_init_lpar() and move the fallback to a header
  powerpc/mm: Fix build break when PPC_NATIVE=n
  crypto: vmx - Convert to CPU feature based module autoloading
  powerpc: Add module autoloading based on CPU features
  powerpc/powernv/ioda: Fix endianness when reading TCEs
  powerpc/mm: Add memory barrier in __hugepte_alloc()
  powerpc/modules: Never restore r2 for a mprofile-kernel style mcount() call
  powerpc/ftrace: Separate the heuristics for checking call sites
  powerpc: Merge 32-bit and 64-bit setup_arch()
  powerpc/64: Make a few boot functions __init
  powerpc: Re-order setup_panic()
  powerpc: Re-order the call to smp_setup_cpu_maps()
  powerpc/32: Move cache info inits to a separate function
  powerpc/64: Move the content of setup_system() to setup_arch()
  ...
 2016-07-30 21:01:36 -07:00
Uma Krishnan 1bd2b2823e cxlflash: Verify problem state area is mapped before notifying shutdown 
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 704c4b0ddc ("cxlflash: Shutdown notify support
for CXL Flash cards").

As a fix, shutdown notification should only occur when the AFU is
mapped.

Fixes: 704c4b0ddc ("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>
 2016-07-27 00:32:06 -04:00
Andrew Donnellan 1e44727a0b cxl: remove dead Kconfig options 
Remove the CXL_KERNEL_API and CXL_EEH Kconfig options, as they were only
needed to coordinate the merging of the cxlflash driver. Also remove the
stub implementation of cxl_perst_reloads_same_image() in cxlflash which is
only used if CXL_EEH isn't defined (i.e. never).

Suggested-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
 2016-07-19 20:12:29 +10:00
Uma Krishnan 704c4b0ddc cxlflash: Shutdown notify support for CXL Flash cards 
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>
 2016-07-12 23:16:31 -04:00
Uma Krishnan 96e1b660fa cxlflash: Add device dependent flags 
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>
 2016-07-12 23:16:31 -04:00
Manoj N. Kumar f411396d94 cxlflash: Fix to drain operations from previous reset 
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>
 2016-07-12 23:16:31 -04:00
Manoj N. Kumar 635f6b0893 cxlflash: Fix to resolve dead-lock during EEH recovery 
When a cxlflash adapter goes into EEH recovery and multiple processes
(each having established its own context) are active, the EEH recovery
can hang if the processes attempt to recover in parallel. The symptom
logged after a couple of minutes is:

INFO: task eehd:48 blocked for more than 120 seconds.
Not tainted 4.5.0-491-26f710d+ #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
eehd            0    48      2
Call Trace:
__switch_to+0x2f0/0x410
__schedule+0x300/0x980
schedule+0x48/0xc0
rwsem_down_write_failed+0x294/0x410
down_write+0x88/0xb0
cxlflash_pci_error_detected+0x100/0x1c0 [cxlflash]
cxl_vphb_error_detected+0x88/0x110 [cxl]
cxl_pci_error_detected+0xb0/0x1d0 [cxl]
eeh_report_error+0xbc/0x130
eeh_pe_dev_traverse+0x94/0x160
eeh_handle_normal_event+0x17c/0x450
eeh_handle_event+0x184/0x370
eeh_event_handler+0x1c8/0x1d0
kthread+0x110/0x130
ret_from_kernel_thread+0x5c/0xa4
INFO: task blockio:33215 blocked for more than 120 seconds.

Not tainted 4.5.0-491-26f710d+ #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
blockio         0 33215  33213
Call Trace:
0x1 (unreliable)
__switch_to+0x2f0/0x410
__schedule+0x300/0x980
schedule+0x48/0xc0
rwsem_down_read_failed+0x124/0x1d0
down_read+0x68/0x80
cxlflash_ioctl+0x70/0x6f0 [cxlflash]
scsi_ioctl+0x3b0/0x4c0
sg_ioctl+0x960/0x1010
do_vfs_ioctl+0xd8/0x8c0
SyS_ioctl+0xd4/0xf0
system_call+0x38/0xb4
INFO: task eehd:48 blocked for more than 120 seconds.

The hang is because of a 3 way dead-lock:

Process A holds the recovery mutex, and waits for eehd to complete.
Process B holds the semaphore and waits for the recovery mutex.
eehd waits for semaphore.

The fix is to have Process B above release the semaphore before
attempting to acquire the recovery mutex. This will allow
eehd to proceed to completion.

Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
 2016-05-05 21:02:17 -04:00
James Bottomley 6ea7e3873e Merge branch 'fixes-base' into fixes 2016-04-05 06:56:47 -04:00
Manoj N. Kumar ea76543127 cxlflash: Move to exponential back-off when cmd_room is not available 
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>
 2016-03-28 20:43:34 -04:00
Manoj N. Kumar 9526f36026 cxlflash: Fix regression issue with re-ordering patch 
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 6ded8b3cbd ("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: 6ded8b3cbd ("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>
 2016-03-28 20:43:17 -04:00
Linus Torvalds d5e2d00898 powerpc updates for 4.6 
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."
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Merge tag 'powerpc-4.6-1' of 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
  ...
 2016-03-19 15:38:41 -07:00
Frederic Barrat ca946d4e4a cxlflash: Use new cxl_pci_read_adapter_vpd() API 
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>
 2016-03-09 23:40:01 +11:00
Manoj N. Kumar 83430833b4 cxlflash: Increase cmd_per_lun for better throughput 
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>
 2016-03-08 21:17:33 -05:00
Manoj N. Kumar 603ecce95f cxlflash: Fix to avoid unnecessary scan with internal LUNs 
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>
 2016-03-08 21:17:33 -05:00
Uma Krishnan 5d1952acd0 cxlflash: Reorder user context initialization 
In order to support cxlflash in the PowerVM environment, underlying
hypervisor APIs have imposed a kernel API ordering change.

For the superpipe access to LUN, user applications need a context.
The cxlflash module creates this context by making a sequence of
cxl calls. In the current code, a context is initialized via
cxl_dev_context_init() followed by cxl_process_element(), a function
that obtains the process element id. Finally, cxl_start_work()
is called to attach the process element.

In the PowerVM environment, a process element id cannot be obtained
from the hypervisor until the process element is attached. The
cxlflash module is unable to create contexts without a valid
process element id.

To fix this problem, cxl_start_work() is called before obtaining
the process element id.

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>
 2016-03-08 21:17:33 -05:00
Matthew R. Ochs 8a96b52af5 cxlflash: Simplify attach path error cleanup 
The cxlflash_disk_attach() routine currently uses a cascading error
gate strategy for its error cleanup path. While this strategy is
commonly used to handle cleanup scenarios, it is too restrictive when
function callouts need to be restructured. Problems range from
inserting error path bugs in previously 'good' code to the cleanup
path imposing design changes to how the normal path is structured.
A less restrictive approach is needed to support ordering changes
that come about when operating in different environments.

To overcome this restriction, the error cleanup path is modified to
have a single entrypoint and use conditional logic to cleanup where
necessary. Entities that require multiple cleanup steps must be
carefully vetted to ensure their APIs support state. In cases where
they do not (none as of this commit) additional local variables can
be used to maintain state on their behalf.

Signed-off-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>
 2016-03-08 21:17:33 -05:00
Matthew R. Ochs 5e6632d19e cxlflash: Split out context initialization 
Presently, context information structures are allocated and
initialized in the same routine, create_context(). This imposes
an ordering restriction such that all pieces of information needed
to initialize a context must be known before the context is even
allocated.

This design point is not flexible when the order of context
creation needs to be modified. Specifically, this can lead to
problems when members of the context information structure are
a part of an ordering dependency (i.e. - the 'work' structure
embedded within the context).

To remedy, the allocation is left as-is, inside of the existing
create_context() routine and the initialization is transitioned
to a new void routine, init_context(). At the same time, in
anticipation of these routines not being called in sequence, a
state boolean is added to the context information structure to
track when the context has been initilized. The context teardown
routine, destroy_context(), is modified to support being called
with a non-initialized context.

Signed-off-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>
 2016-03-08 21:17:33 -05:00
Uma Krishnan 6ded8b3cbd cxlflash: Unmap problem state area before detaching master context 
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>
 2016-03-08 21:17:33 -05:00
Manoj N. Kumar 961487e46a cxlflash: Simplify PCI registration 
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>
 2016-03-08 21:17:33 -05:00
Manoj Kumar a2746fb16e cxlflash: Enable device id for future IBM CXL adapter 
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>
 2016-01-06 20:58:29 -05:00
Manoj Kumar b45cdbaf9f cxlflash: Resolve oops in wait_port_offline 
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>
 2016-01-06 20:55:01 -05:00
Manoj Kumar ee91e332a6 cxlflash: Fix to resolve cmd leak after host reset 
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>
 2016-01-06 20:52:31 -05:00
Uma Krishnan 8559921891 cxlflash: Removed driver date print 
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>
 2016-01-06 20:51:14 -05:00
Matthew R. Ochs d5e26bb1d8 cxlflash: Fix to avoid virtual LUN failover failure 
Applications which use virtual LUN's that are backed by a physical LUN
over both adapter ports may experience an I/O failure in the event of a
link loss (e.g. cable pull).

Virtual LUNs may be accessed through one or both ports of the adapter.
This access is encoded in the translation entries that comprise the
virtual LUN and used by the AFU for load-balancing I/O and handling
failover scenarios. In a link loss scenario, even though the AFU is able
to maintain connectivity to the LUN, it is up to the application to
retry the failed I/O. When applications are unaware of the virtual LUN's
underlying topology, they are unable to make a sound decision of when to
retry an I/O and therefore are forced to make their reaction to a failed
I/O absolute. The result is either a failure to retry I/O or increased
latency for scenarios where a retry is pointless.

To remedy this scenario, provide feedback back to the application on
virtual LUN creation as to which ports the LUN may be accessed. LUN's
spanning both ports are candidates for a retry in a presence of an I/O
failure.

Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Acked-by: Manoj Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
 2016-01-06 20:50:08 -05:00
Manoj Kumar a9be294ecb cxlflash: Fix to escalate LINK_RESET also on port 1 
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>
 2016-01-06 20:48:02 -05:00
Geliang Tang 21891a452a cxlflash: drop unlikely before IS_ERR_OR_NULL 
IS_ERR_OR_NULL already contain an unlikely compiler flag. Drop it.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Acked-by: Manoj 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>
 2015-12-10 12:55:37 -05:00
Dan Carpenter e37390bee6 cxlflash: a couple off by one bugs 
The "> MAX_CONTEXT" should be ">= MAX_CONTEXT".  Otherwise we go one
step beyond the end of the cfg->ctx_tbl[] array.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Manoj Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
 2015-12-10 12:53:52 -05:00
Matthew R. Ochs a82544c7ba cxlflash: Fix to avoid bypassing context cleanup 
Contexts may be skipped over for cleanup in situations where contention
for the adapter's table-list mutex is experienced in the presence of a
signal during the execution of the release handler.

This can lead to two known issues:

 - A hang condition on remove as that path tries to wait for users to
   cleanup - something that will never complete should this scenario play
   out as the user has already cleaned up from their perspective.

 - An Oops in the unmap_mapping_range() call that is made as part of
   the user waiting mechanism that is invoked on remove when contexts
   are found to still exist.

The root cause of this issue can be found in get_context() and how the
table-list mutex is acquired. As this code path is shared by several
different access points within the driver, a decision was made during
the development cycle to acquire this mutex in this location using the
interruptible version of the mutex locking service. In almost all of
the use-cases and environmental scenarios this holds up, even when the
mutex is contended. However, for critical system threads (such as the
release handler), failing to acquire the mutex and bailing with the
intention of the user being able to try again later is unacceptable.

In such a scenario, the context _must_ be derived as it is on an
irreversible path to being freed. Without being able to derive the
context, the code mistakenly assumes that it has already been freed
and proceeds to free up the underlying CXL context resources. From
this point on, any usage of [the now stale] CXL context resources
will result in undefined behavior. This is root cause of the Oops
mentioned as the second known issue as the mapping passed to the
unmap_mapping_range() service is owned by the CXL context.

To fix this problem, acquisition of the table-list mutex within
get_context() is simply changed to use the uninterruptible version
of the mutex locking service. This is safe as the timing windows for
holding this mutex are short and also protected against blocking.

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>
 2015-10-30 17:25:34 +09:00
Matthew R. Ochs 0d73122c32 cxlflash: Fix to avoid lock instrumentation rejection 
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>
 2015-10-30 17:24:38 +09:00
Matthew R. Ochs 1a47401bb3 cxlflash: Fix to avoid corrupting port selection mask 
The port selection mask of a LUN can be corrupted when the manage LUN
ioctl (DK_CXLFLASH_MANAGE_LUN) is issued more than once for any device.

This mask indicates to the AFU which port[s] can be used for a data
transfer to/from a particular LUN. The mask is critical to ensuring the
correct behavior when using the virtual LUN function of this adapter.
When the mask is configured for both ports, an I/O may be sent to either
port as the AFU assumes that each port has access to the same physical
device (specified by LUN ID in the port LUN table).

In a situation where the mask becomes incorrectly configured to reflect
access to both ports when in fact there is only access through a single
port, an I/O can be targeted to the wrong physical device. This can lead
to data corruption among other ill effects (e.g. security leaks).

The cause for this corruption is the assumption that the ioctl will only
be called a second time for a LUN when it is being configured for access
via a second port. A boolean 'newly_created' variable is used to
differentiate between a LUN that was created (and subsequently configured
for single port access) and one that is destined for access across both
ports. While initially set to 'true', this sticky boolean is toggled to
the 'false' state during a lookup on any next ioctl performed on a device
with a matching WWN/WWID. The code fails to realize that the match could
in fact be the same device calling in again. From here, an assumption is
made that any LUN with 'newly_created' set to 'false' is configured for
access over both ports and the port selection mask is set to reflect this.
Any future attempts to use this LUN for hosting a virtual LUN will result
in the port LUN table being incorrectly programmed.

As a remedy, the 'newly_created' concept was removed entirely and replaced
with code that always constructs the port selection mask based upon the
SCSI channel of the LUN being accessed. The bits remain sticky, therefore
allowing for a device to be accessed over both ports when that is in fact
the correct physical configuration.

Also included in this commit are a few minor related changes to enhance
the fix and provide better debug information for port selection mask and
port LUN table bugs in the future. These include renaming refresh_local()
to lookup_local(), tracing the WWN/WWID as a big-endian entity, and
tracing the port selection mask, SCSI channel, and LUN ID each time the
port LUN table is programmed.

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>
 2015-10-30 17:23:55 +09:00
Manoj Kumar e6e6df3f71 cxlflash: Fix to escalate to LINK_RESET on login timeout 
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>
 2015-10-30 17:23:12 +09:00
Matthew R. Ochs ee3491ba8f cxlflash: Fix to avoid leaving dangling interrupt resources 
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>
 2015-10-30 17:22:44 +09:00
Matthew R. Ochs aacb4ff69e cxlflash: Fix to avoid potential deadlock on EEH 
Ioctl threads that use scsi_execute() can run for an excessive amount
of time due to the fact that they have lengthy timeouts and retry logic
built in. Under normal operation this is not an issue. However, once EEH
enters the picture, a long execution time coupled with the possibility
that a timeout can trigger entry to the driver via registered reset
callbacks becomes a liability.

In particular, a deadlock can occur when an EEH event is encountered
while in running in scsi_execute(). As part of the recovery, the EEH
handler drains all currently running ioctls, waiting until they have
completed before proceeding with a reset. As the scsi_execute()'s are
situated on the ioctl path, the EEH handler will wait until they (and
the remainder of the ioctl handler they're associated with) have
completed. Normally this would not be much of an issue aside from the
longer recovery period. Unfortunately, the scsi_execute() triggers a
reset when it times out. The reset handler will see that the device is
already being reset and wait until that reset completed. This creates
a condition where the EEH handler becomes stuck, infinitely waiting for
the ioctl thread to complete.

To avoid this behavior, temporarily unmark the scsi_execute() threads
as an ioctl thread by releasing the ioctl read semaphore. This allows
the EEH handler to proceed with a recovery while the thread is still
running. Once the scsi_execute() returns, the ioctl read semaphore is
reacquired and the adapter state is rechecked in case it changed while
inside of scsi_execute(). The state check will wait if the adapter is
still being recovered or returns a failure if the recovery failed. In
the event that the adapter reset failed, the failure is simply returned
as the ioctl would be unable to continue.

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: Daniel Axtens <dja@axtens.net>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
 2015-10-30 17:22:11 +09:00
Matthew R. Ochs fa3f2c6eb1 cxlflash: Correct trace string 
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>
 2015-10-30 17:21:38 +09:00
Matthew R. Ochs 17ead26f23 cxlflash: Fix to avoid corrupting adapter fops 
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>
 2015-10-30 17:20:00 +09:00
Manoj Kumar b22b4037a0 cxlflash: Fix to double the delay each time 
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>
 2015-10-30 17:19:35 +09:00
Matthew R. Ochs af10483e5e cxlflash: Fix to prevent stale AFU RRQ 
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>
 2015-10-30 17:18:53 +09:00
Matthew R. Ochs f15fbf8d4e cxlflash: Correct spelling, grammar, and alignment mistakes 
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>
 2015-10-30 17:18:28 +09:00