Merge tag 'pci-v4.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI updates from Bjorn Helgaas:

 - add framework for supporting PCIe devices in Endpoint mode (Kishon
   Vijay Abraham I)

 - use non-postable PCI config space mappings when possible (Lorenzo
   Pieralisi)

 - clean up and unify mmap of PCI BARs (David Woodhouse)

 - export and unify Function Level Reset support (Christoph Hellwig)

 - avoid FLR for Intel 82579 NICs (Sasha Neftin)

 - add pci_request_irq() and pci_free_irq() helpers (Christoph Hellwig)

 - short-circuit config access failures for disconnected devices (Keith
   Busch)

 - remove D3 sleep delay when possible (Adrian Hunter)

 - freeze PME scan before suspending devices (Lukas Wunner)

 - stop disabling MSI/MSI-X in pci_device_shutdown() (Prarit Bhargava)

 - disable boot interrupt quirk for ASUS M2N-LR (Stefan Assmann)

 - add arch-specific alignment control to improve device passthrough by
   avoiding multiple BARs in a page (Yongji Xie)

 - add sysfs sriov_drivers_autoprobe to control VF driver binding
   (Bodong Wang)

 - allow slots below PCI-to-PCIe "reverse bridges" (Bjorn Helgaas)

 - fix crashes when unbinding host controllers that don't support
   removal (Brian Norris)

 - add driver for MicroSemi Switchtec management interface (Logan
   Gunthorpe)

 - add driver for Faraday Technology FTPCI100 host bridge (Linus
   Walleij)

 - add i.MX7D support (Andrey Smirnov)

 - use generic MSI support for Aardvark (Thomas Petazzoni)

 - make Rockchip driver modular (Brian Norris)

 - advertise 128-byte Read Completion Boundary support for Rockchip
   (Shawn Lin)

 - advertise PCI_EXP_LNKSTA_SLC for Rockchip root port (Shawn Lin)

 - convert atomic_t to refcount_t in HV driver (Elena Reshetova)

 - add CPU IRQ affinity in HV driver (K. Y. Srinivasan)

 - fix PCI bus removal in HV driver (Long Li)

 - add support for ThunderX2 DMA alias topology (Jayachandran C)

 - add ThunderX pass2.x 2nd node MCFG quirk (Tomasz Nowicki)

 - add ITE 8893 bridge DMA alias quirk (Jarod Wilson)

 - restrict Cavium ACS quirk only to CN81xx/CN83xx/CN88xx devices
   (Manish Jaggi)

* tag 'pci-v4.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (146 commits)
  PCI: Don't allow unbinding host controllers that aren't prepared
  ARM: DRA7: clockdomain: Change the CLKTRCTRL of CM_PCIE_CLKSTCTRL to SW_WKUP
  MAINTAINERS: Add PCI Endpoint maintainer
  Documentation: PCI: Add userguide for PCI endpoint test function
  tools: PCI: Add sample test script to invoke pcitest
  tools: PCI: Add a userspace tool to test PCI endpoint
  Documentation: misc-devices: Add Documentation for pci-endpoint-test driver
  misc: Add host side PCI driver for PCI test function device
  PCI: Add device IDs for DRA74x and DRA72x
  dt-bindings: PCI: dra7xx: Add DT bindings to enable unaligned access
  PCI: dwc: dra7xx: Workaround for errata id i870
  dt-bindings: PCI: dra7xx: Add DT bindings for PCI dra7xx EP mode
  PCI: dwc: dra7xx: Add EP mode support
  PCI: dwc: dra7xx: Facilitate wrapper and MSI interrupts to be enabled independently
  dt-bindings: PCI: Add DT bindings for PCI designware EP mode
  PCI: dwc: designware: Add EP mode support
  Documentation: PCI: Add binding documentation for pci-test endpoint function
  ixgbe: Use pcie_flr() instead of duplicating it
  IB/hfi1: Use pcie_flr() instead of duplicating it
  PCI: imx6: Fix spelling mistake: "contol" -> "control"
  ...

1 files changed, 80 insertions, 0 deletions

diff --git a/Documentation/switchtec.txt b/Documentation/switchtec.txt
new file mode 100644
index 000000000000..a0a9c7b3d4d5
--- /dev/null
+++ b/Documentation/switchtec.txt
@@ -0,0 +1,80 @@
+========================
+Linux Switchtec Support
+========================
+
+Microsemi's "Switchtec" line of PCI switch devices is already
+supported by the kernel with standard PCI switch drivers. However, the
+Switchtec device advertises a special management endpoint which
+enables some additional functionality. This includes:
+
+* Packet and Byte Counters
+* Firmware Upgrades
+* Event and Error logs
+* Querying port link status
+* Custom user firmware commands
+
+The switchtec kernel module implements this functionality.
+
+
+Interface
+=========
+
+The primary means of communicating with the Switchtec management firmware is
+through the Memory-mapped Remote Procedure Call (MRPC) interface.
+Commands are submitted to the interface with a 4-byte command
+identifier and up to 1KB of command specific data. The firmware will
+respond with a 4 bytes return code and up to 1KB of command specific
+data. The interface only processes a single command at a time.
+
+
+Userspace Interface
+===================
+
+The MRPC interface will be exposed to userspace through a simple char
+device: /dev/switchtec#, one for each management endpoint in the system.
+
+The char device has the following semantics:
+
+* A write must consist of at least 4 bytes and no more than 1028 bytes.
+  The first four bytes will be interpreted as the command to run and
+  the remainder will be used as the input data. A write will send the
+  command to the firmware to begin processing.
+
+* Each write must be followed by exactly one read. Any double write will
+  produce an error and any read that doesn't follow a write will
+  produce an error.
+
+* A read will block until the firmware completes the command and return
+  the four bytes of status plus up to 1024 bytes of output data. (The
+  length will be specified by the size parameter of the read call --
+  reading less than 4 bytes will produce an error.
+
+* The poll call will also be supported for userspace applications that
+  need to do other things while waiting for the command to complete.
+
+The following IOCTLs are also supported by the device:
+
+* SWITCHTEC_IOCTL_FLASH_INFO - Retrieve firmware length and number
+  of partitions in the device.
+
+* SWITCHTEC_IOCTL_FLASH_PART_INFO - Retrieve address and lengeth for
+  any specified partition in flash.
+
+* SWITCHTEC_IOCTL_EVENT_SUMMARY - Read a structure of bitmaps
+  indicating all uncleared events.
+
+* SWITCHTEC_IOCTL_EVENT_CTL - Get the current count, clear and set flags
+  for any event. This ioctl takes in a switchtec_ioctl_event_ctl struct
+  with the event_id, index and flags set (index being the partition or PFF
+  number for non-global events). It returns whether the event has
+  occurred, the number of times and any event specific data. The flags
+  can be used to clear the count or enable and disable actions to
+  happen when the event occurs.
+  By using the SWITCHTEC_IOCTL_EVENT_FLAG_EN_POLL flag,
+  you can set an event to trigger a poll command to return with
+  POLLPRI. In this way, userspace can wait for events to occur.
+
+* SWITCHTEC_IOCTL_PFF_TO_PORT and SWITCHTEC_IOCTL_PORT_TO_PFF convert
+  between PCI Function Framework number (used by the event system)
+  and Switchtec Logic Port ID and Partition number (which is more
+  user friendly).