Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull first round of SCSI updates from James Bottomley:
 "This includes one new driver: cxlflash plus the usual grab bag of
  updates for the major drivers: qla2xxx, ipr, storvsc, pm80xx, hptiop,
  plus a few assorted fixes.

  There's another tranch coming, but I want to incubate it another few
  days in the checkers, plus it includes a mpt2sas separated lifetime
  fix, which Avago won't get done testing until Friday"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (85 commits)
  aic94xx: set an error code on failure
  storvsc: Set the error code correctly in failure conditions
  storvsc: Allow write_same when host is windows 10
  storvsc: use storage protocol version to determine storage capabilities
  storvsc: use correct defaults for values determined by protocol negotiation
  storvsc: Untangle the storage protocol negotiation from the vmbus protocol negotiation.
  storvsc: Use a single value to track protocol versions
  storvsc: Rather than look for sets of specific protocol versions, make decisions based on ranges.
  cxlflash: Remove unused variable from queuecommand
  cxlflash: shift wrapping bug in afu_link_reset()
  cxlflash: off by one bug in cxlflash_show_port_status()
  cxlflash: Virtual LUN support
  cxlflash: Superpipe support
  cxlflash: Base error recovery support
  qla2xxx: Update driver version to 8.07.00.26-k
  qla2xxx: Add pci device id 0x2261.
  qla2xxx: Fix missing device login retries.
  qla2xxx: do not clear slot in outstanding cmd array
  qla2xxx: Remove decrement of sp reference count in abort handler.
  qla2xxx: Add support to show MPI and PEP FW version for ISP27xx.
  ...

1 files changed, 318 insertions, 0 deletions

diff --git a/Documentation/powerpc/cxlflash.txt b/Documentation/powerpc/cxlflash.txt
new file mode 100644
index 0000000..4202d1b
--- /dev/null
+++ b/Documentation/powerpc/cxlflash.txt
@@ -0,0 +1,318 @@
+Introduction
+============
+
+    The IBM Power architecture provides support for CAPI (Coherent
+    Accelerator Power Interface), which is available to certain PCIe slots
+    on Power 8 systems. CAPI can be thought of as a special tunneling
+    protocol through PCIe that allow PCIe adapters to look like special
+    purpose co-processors which can read or write an application's
+    memory and generate page faults. As a result, the host interface to
+    an adapter running in CAPI mode does not require the data buffers to
+    be mapped to the device's memory (IOMMU bypass) nor does it require
+    memory to be pinned.
+
+    On Linux, Coherent Accelerator (CXL) kernel services present CAPI
+    devices as a PCI device by implementing a virtual PCI host bridge.
+    This abstraction simplifies the infrastructure and programming
+    model, allowing for drivers to look similar to other native PCI
+    device drivers.
+
+    CXL provides a mechanism by which user space applications can
+    directly talk to a device (network or storage) bypassing the typical
+    kernel/device driver stack. The CXL Flash Adapter Driver enables a
+    user space application direct access to Flash storage.
+
+    The CXL Flash Adapter Driver is a kernel module that sits in the
+    SCSI stack as a low level device driver (below the SCSI disk and
+    protocol drivers) for the IBM CXL Flash Adapter. This driver is
+    responsible for the initialization of the adapter, setting up the
+    special path for user space access, and performing error recovery. It
+    communicates directly the Flash Accelerator Functional Unit (AFU)
+    as described in Documentation/powerpc/cxl.txt.
+
+    The cxlflash driver supports two, mutually exclusive, modes of
+    operation at the device (LUN) level:
+
+        - Any flash device (LUN) can be configured to be accessed as a
+          regular disk device (i.e.: /dev/sdc). This is the default mode.
+
+        - Any flash device (LUN) can be configured to be accessed from
+          user space with a special block library. This mode further
+          specifies the means of accessing the device and provides for
+          either raw access to the entire LUN (referred to as direct
+          or physical LUN access) or access to a kernel/AFU-mediated
+          partition of the LUN (referred to as virtual LUN access). The
+          segmentation of a disk device into virtual LUNs is assisted
+          by special translation services provided by the Flash AFU.
+
+Overview
+========
+
+    The Coherent Accelerator Interface Architecture (CAIA) introduces a
+    concept of a master context. A master typically has special privileges
+    granted to it by the kernel or hypervisor allowing it to perform AFU
+    wide management and control. The master may or may not be involved
+    directly in each user I/O, but at the minimum is involved in the
+    initial setup before the user application is allowed to send requests
+    directly to the AFU.
+
+    The CXL Flash Adapter Driver establishes a master context with the
+    AFU. It uses memory mapped I/O (MMIO) for this control and setup. The
+    Adapter Problem Space Memory Map looks like this:
+
+                     +-------------------------------+
+                     |    512 * 64 KB User MMIO      |
+                     |        (per context)          |
+                     |       User Accessible         |
+                     +-------------------------------+
+                     |    512 * 128 B per context    |
+                     |    Provisioning and Control   |
+                     |   Trusted Process accessible  |
+                     +-------------------------------+
+                     |         64 KB Global          |
+                     |   Trusted Process accessible  |
+                     +-------------------------------+
+
+    This driver configures itself into the SCSI software stack as an
+    adapter driver. The driver is the only entity that is considered a
+    Trusted Process to program the Provisioning and Control and Global
+    areas in the MMIO Space shown above.  The master context driver
+    discovers all LUNs attached to the CXL Flash adapter and instantiates
+    scsi block devices (/dev/sdb, /dev/sdc etc.) for each unique LUN
+    seen from each path.
+
+    Once these scsi block devices are instantiated, an application
+    written to a specification provided by the block library may get
+    access to the Flash from user space (without requiring a system call).
+
+    This master context driver also provides a series of ioctls for this
+    block library to enable this user space access.  The driver supports
+    two modes for accessing the block device.
+
+    The first mode is called a virtual mode. In this mode a single scsi
+    block device (/dev/sdb) may be carved up into any number of distinct
+    virtual LUNs. The virtual LUNs may be resized as long as the sum of
+    the sizes of all the virtual LUNs, along with the meta-data associated
+    with it does not exceed the physical capacity.
+
+    The second mode is called the physical mode. In this mode a single
+    block device (/dev/sdb) may be opened directly by the block library
+    and the entire space for the LUN is available to the application.
+
+    Only the physical mode provides persistence of the data.  i.e. The
+    data written to the block device will survive application exit and
+    restart and also reboot. The virtual LUNs do not persist (i.e. do
+    not survive after the application terminates or the system reboots).
+
+
+Block library API
+=================
+
+    Applications intending to get access to the CXL Flash from user
+    space should use the block library, as it abstracts the details of
+    interfacing directly with the cxlflash driver that are necessary for
+    performing administrative actions (i.e.: setup, tear down, resize).
+    The block library can be thought of as a 'user' of services,
+    implemented as IOCTLs, that are provided by the cxlflash driver
+    specifically for devices (LUNs) operating in user space access
+    mode. While it is not a requirement that applications understand
+    the interface between the block library and the cxlflash driver,
+    a high-level overview of each supported service (IOCTL) is provided
+    below.
+
+    The block library can be found on GitHub:
+    http://www.github.com/mikehollinger/ibmcapikv
+
+
+CXL Flash Driver IOCTLs
+=======================
+
+    Users, such as the block library, that wish to interface with a flash
+    device (LUN) via user space access need to use the services provided
+    by the cxlflash driver. As these services are implemented as ioctls,
+    a file descriptor handle must first be obtained in order to establish
+    the communication channel between a user and the kernel.  This file
+    descriptor is obtained by opening the device special file associated
+    with the scsi disk device (/dev/sdb) that was created during LUN
+    discovery. As per the location of the cxlflash driver within the
+    SCSI protocol stack, this open is actually not seen by the cxlflash
+    driver. Upon successful open, the user receives a file descriptor
+    (herein referred to as fd1) that should be used for issuing the
+    subsequent ioctls listed below.
+
+    The structure definitions for these IOCTLs are available in:
+    uapi/scsi/cxlflash_ioctl.h
+
+DK_CXLFLASH_ATTACH
+------------------
+
+    This ioctl obtains, initializes, and starts a context using the CXL
+    kernel services. These services specify a context id (u16) by which
+    to uniquely identify the context and its allocated resources. The
+    services additionally provide a second file descriptor (herein
+    referred to as fd2) that is used by the block library to initiate
+    memory mapped I/O (via mmap()) to the CXL flash device and poll for
+    completion events. This file descriptor is intentionally installed by
+    this driver and not the CXL kernel services to allow for intermediary
+    notification and access in the event of a non-user-initiated close(),
+    such as a killed process. This design point is described in further
+    detail in the description for the DK_CXLFLASH_DETACH ioctl.
+
+    There are a few important aspects regarding the "tokens" (context id
+    and fd2) that are provided back to the user:
+
+        - These tokens are only valid for the process under which they
+          were created. The child of a forked process cannot continue
+          to use the context id or file descriptor created by its parent
+          (see DK_CXLFLASH_VLUN_CLONE for further details).
+
+        - These tokens are only valid for the lifetime of the context and
+          the process under which they were created. Once either is
+          destroyed, the tokens are to be considered stale and subsequent
+          usage will result in errors.
+
+        - When a context is no longer needed, the user shall detach from
+          the context via the DK_CXLFLASH_DETACH ioctl.
+
+        - A close on fd2 will invalidate the tokens. This operation is not
+          required by the user.
+
+DK_CXLFLASH_USER_DIRECT
+-----------------------
+    This ioctl is responsible for transitioning the LUN to direct
+    (physical) mode access and configuring the AFU for direct access from
+    user space on a per-context basis. Additionally, the block size and
+    last logical block address (LBA) are returned to the user.
+
+    As mentioned previously, when operating in user space access mode,
+    LUNs may be accessed in whole or in part. Only one mode is allowed
+    at a time and if one mode is active (outstanding references exist),
+    requests to use the LUN in a different mode are denied.
+
+    The AFU is configured for direct access from user space by adding an
+    entry to the AFU's resource handle table. The index of the entry is
+    treated as a resource handle that is returned to the user. The user
+    is then able to use the handle to reference the LUN during I/O.
+
+DK_CXLFLASH_USER_VIRTUAL
+------------------------
+    This ioctl is responsible for transitioning the LUN to virtual mode
+    of access and configuring the AFU for virtual access from user space
+    on a per-context basis. Additionally, the block size and last logical
+    block address (LBA) are returned to the user.
+
+    As mentioned previously, when operating in user space access mode,
+    LUNs may be accessed in whole or in part. Only one mode is allowed
+    at a time and if one mode is active (outstanding references exist),
+    requests to use the LUN in a different mode are denied.
+
+    The AFU is configured for virtual access from user space by adding
+    an entry to the AFU's resource handle table. The index of the entry
+    is treated as a resource handle that is returned to the user. The
+    user is then able to use the handle to reference the LUN during I/O.
+
+    By default, the virtual LUN is created with a size of 0. The user
+    would need to use the DK_CXLFLASH_VLUN_RESIZE ioctl to adjust the grow
+    the virtual LUN to a desired size. To avoid having to perform this
+    resize for the initial creation of the virtual LUN, the user has the
+    option of specifying a size as part of the DK_CXLFLASH_USER_VIRTUAL
+    ioctl, such that when success is returned to the user, the
+    resource handle that is provided is already referencing provisioned
+    storage. This is reflected by the last LBA being a non-zero value.
+
+DK_CXLFLASH_VLUN_RESIZE
+-----------------------
+    This ioctl is responsible for resizing a previously created virtual
+    LUN and will fail if invoked upon a LUN that is not in virtual
+    mode. Upon success, an updated last LBA is returned to the user
+    indicating the new size of the virtual LUN associated with the
+    resource handle.
+
+    The partitioning of virtual LUNs is jointly mediated by the cxlflash
+    driver and the AFU. An allocation table is kept for each LUN that is
+    operating in the virtual mode and used to program a LUN translation
+    table that the AFU references when provided with a resource handle.
+
+DK_CXLFLASH_RELEASE
+-------------------
+    This ioctl is responsible for releasing a previously obtained
+    reference to either a physical or virtual LUN. This can be
+    thought of as the inverse of the DK_CXLFLASH_USER_DIRECT or
+    DK_CXLFLASH_USER_VIRTUAL ioctls. Upon success, the resource handle
+    is no longer valid and the entry in the resource handle table is
+    made available to be used again.
+
+    As part of the release process for virtual LUNs, the virtual LUN
+    is first resized to 0 to clear out and free the translation tables
+    associated with the virtual LUN reference.
+
+DK_CXLFLASH_DETACH
+------------------
+    This ioctl is responsible for unregistering a context with the
+    cxlflash driver and release outstanding resources that were
+    not explicitly released via the DK_CXLFLASH_RELEASE ioctl. Upon
+    success, all "tokens" which had been provided to the user from the
+    DK_CXLFLASH_ATTACH onward are no longer valid.
+
+DK_CXLFLASH_VLUN_CLONE
+----------------------
+    This ioctl is responsible for cloning a previously created
+    context to a more recently created context. It exists solely to
+    support maintaining user space access to storage after a process
+    forks. Upon success, the child process (which invoked the ioctl)
+    will have access to the same LUNs via the same resource handle(s)
+    and fd2 as the parent, but under a different context.
+
+    Context sharing across processes is not supported with CXL and
+    therefore each fork must be met with establishing a new context
+    for the child process. This ioctl simplifies the state management
+    and playback required by a user in such a scenario. When a process
+    forks, child process can clone the parents context by first creating
+    a context (via DK_CXLFLASH_ATTACH) and then using this ioctl to
+    perform the clone from the parent to the child.
+
+    The clone itself is fairly simple. The resource handle and lun
+    translation tables are copied from the parent context to the child's
+    and then synced with the AFU.
+
+DK_CXLFLASH_VERIFY
+------------------
+    This ioctl is used to detect various changes such as the capacity of
+    the disk changing, the number of LUNs visible changing, etc. In cases
+    where the changes affect the application (such as a LUN resize), the
+    cxlflash driver will report the changed state to the application.
+
+    The user calls in when they want to validate that a LUN hasn't been
+    changed in response to a check condition. As the user is operating out
+    of band from the kernel, they will see these types of events without
+    the kernel's knowledge. When encountered, the user's architected
+    behavior is to call in to this ioctl, indicating what they want to
+    verify and passing along any appropriate information. For now, only
+    verifying a LUN change (ie: size different) with sense data is
+    supported.
+
+DK_CXLFLASH_RECOVER_AFU
+-----------------------
+    This ioctl is used to drive recovery (if such an action is warranted)
+    of a specified user context. Any state associated with the user context
+    is re-established upon successful recovery.
+
+    User contexts are put into an error condition when the device needs to
+    be reset or is terminating. Users are notified of this error condition
+    by seeing all 0xF's on an MMIO read. Upon encountering this, the
+    architected behavior for a user is to call into this ioctl to recover
+    their context. A user may also call into this ioctl at any time to
+    check if the device is operating normally. If a failure is returned
+    from this ioctl, the user is expected to gracefully clean up their
+    context via release/detach ioctls. Until they do, the context they
+    hold is not relinquished. The user may also optionally exit the process
+    at which time the context/resources they held will be freed as part of
+    the release fop.
+
+DK_CXLFLASH_MANAGE_LUN
+----------------------
+    This ioctl is used to switch a LUN from a mode where it is available
+    for file-system access (legacy), to a mode where it is set aside for
+    exclusive user space access (superpipe). In case a LUN is visible
+    across multiple ports and adapters, this ioctl is used to uniquely
+    identify each LUN by its World Wide Node Name (WWNN).