Commit 03f51d4e authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'powerpc-4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux 

Pull powerpc updates from Michael Ellerman:
 "Highlights:

   - Enable support for memory protection keys aka "pkeys" on Power7/8/9
     when using the hash table MMU.

   - Extend our interrupt soft masking to support masking PMU interrupts
     as well as "normal" interrupts, and then use that to implement
     local_t for a ~4x speedup vs the current atomics-based
     implementation.

   - A new driver "ocxl" for "Open Coherent Accelerator Processor
     Interface (OpenCAPI)" devices.

   - Support for new device tree properties on PowerVM to describe
     hotpluggable memory and devices.

   - Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE to the 64-bit
     VDSO.

   - Freescale updates from Scott: fixes for CPM GPIO and an FSL PCI
     erratum workaround, plus a minor cleanup patch.

  As well as quite a lot of other changes all over the place, and small
  fixes and cleanups as always.

  Thanks to: Alan Modra, Alastair D'Silva, Alexey Kardashevskiy,
  Alistair Popple, Andreas Schwab, Andrew Donnellan, Aneesh Kumar K.V,
  Anju T Sudhakar, Anshuman Khandual, Anton Blanchard, Arnd Bergmann,
  Balbir Singh, Benjamin Herrenschmidt, Bhaktipriya Shridhar, Bryant G.
  Ly, Cédric Le Goater, Christophe Leroy, Christophe Lombard, Cyril Bur,
  David Gibson, Desnes A. Nunes do Rosario, Dmitry Torokhov, Frederic
  Barrat, Geert Uytterhoeven, Guilherme G. Piccoli, Gustavo A. R. Silva,
  Gustavo Romero, Ivan Mikhaylov, Joakim Tjernlund, Joe Perches, Josh
  Poimboeuf, Juan J. Alvarez, Julia Cartwright, Kamalesh Babulal,
  Madhavan Srinivasan, Mahesh Salgaonkar, Mathieu Malaterre, Michael
  Bringmann, Michael Hanselmann, Michael Neuling, Nathan Fontenot,
  Naveen N. Rao, Nicholas Piggin, Paul Mackerras, Philippe Bergheaud,
  Ram Pai, Russell Currey, Santosh Sivaraj, Scott Wood, Seth Forshee,
  Simon Guo, Stewart Smith, Sukadev Bhattiprolu, Thiago Jung Bauermann,
  Vaibhav Jain, Vasyl Gomonovych"

* tag 'powerpc-4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (199 commits)
  powerpc/mm/radix: Fix build error when RADIX_MMU=n
  macintosh/ams-input: Use true and false for boolean values
  macintosh: change some data types from int to bool
  powerpc/watchdog: Print the NIP in soft_nmi_interrupt()
  powerpc/watchdog: regs can't be null in soft_nmi_interrupt()
  powerpc/watchdog: Tweak watchdog printks
  powerpc/cell: Remove axonram driver
  rtc-opal: Fix handling of firmware error codes, prevent busy loops
  powerpc/mpc52xx_gpt: make use of raw_spinlock variants
  macintosh/adb: Properly mark continued kernel messages
  powerpc/pseries: Fix cpu hotplug crash with memoryless nodes
  powerpc/numa: Ensure nodes initialized for hotplug
  powerpc/numa: Use ibm,max-associativity-domains to discover possible nodes
  powerpc/kernel: Block interrupts when updating TIDR
  powerpc/powernv/idoa: Remove unnecessary pcidev from pci_dn
  powerpc/mm/nohash: do not flush the entire mm when range is a single page
  powerpc/pseries: Add Initialization of VF Bars
  powerpc/pseries/pci: Associate PEs to VFs in configure SR-IOV
  powerpc/eeh: Add EEH notify resume sysfs
  powerpc/eeh: Add EEH operations to notify resume
  ...
parents 367b0df1 015eb1b8

Documentation/ABI/testing/sysfs-class-ocxl

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What:		/sys/class/ocxl/<afu name>/afu_version

Date:		January 2018

Contact:	linuxppc-dev@lists.ozlabs.org

Description:	read only

		Version of the AFU, in the format <major>:<minor>

		Reflects what is read in the configuration space of the AFU



What:		/sys/class/ocxl/<afu name>/contexts

Date:		January 2018

Contact:	linuxppc-dev@lists.ozlabs.org

Description:	read only

		Number of contexts for the AFU, in the format <n>/<max>

		where:

			n:	number of currently active contexts, for debug

			max:	maximum number of contexts supported by the AFU



What:		/sys/class/ocxl/<afu name>/pp_mmio_size

Date:		January 2018

Contact:	linuxppc-dev@lists.ozlabs.org

Description:	read only

		Size of the per-process mmio area, as defined in the

		configuration space of the AFU



What:		/sys/class/ocxl/<afu name>/global_mmio_size

Date:		January 2018

Contact:	linuxppc-dev@lists.ozlabs.org

Description:	read only

		Size of the global mmio area, as defined in the

		configuration space of the AFU



What:		/sys/class/ocxl/<afu name>/global_mmio_area

Date:		January 2018

Contact:	linuxppc-dev@lists.ozlabs.org

Description:	read/write

		Give access the global mmio area for the AFU

Documentation/accelerators/ocxl.rst

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========================================================

OpenCAPI (Open Coherent Accelerator Processor Interface)

========================================================



OpenCAPI is an interface between processors and accelerators. It aims

at being low-latency and high-bandwidth. The specification is

developed by the `OpenCAPI Consortium <http://opencapi.org/>`_.



It allows an accelerator (which could be a FPGA, ASICs, ...) to access

the host memory coherently, using virtual addresses. An OpenCAPI

device can also host its own memory, that can be accessed from the

host.



OpenCAPI is known in linux as 'ocxl', as the open, processor-agnostic

evolution of 'cxl' (the driver for the IBM CAPI interface for

powerpc), which was named that way to avoid confusion with the ISDN

CAPI subsystem.





High-level view

===============



OpenCAPI defines a Data Link Layer (DL) and Transaction Layer (TL), to

be implemented on top of a physical link. Any processor or device

implementing the DL and TL can start sharing memory.



::



  +-----------+                         +-------------+

  |           |                         |             |

  |           |                         | Accelerated |

  | Processor |                         |  Function   |

  |           |  +--------+             |    Unit     |  +--------+

  |           |--| Memory |             |    (AFU)    |--| Memory |

  |           |  +--------+             |             |  +--------+

  +-----------+                         +-------------+

       |                                       |

  +-----------+                         +-------------+

  |    TL     |                         |    TLX      |

  +-----------+                         +-------------+

       |                                       |

  +-----------+                         +-------------+

  |    DL     |                         |    DLX      |

  +-----------+                         +-------------+

       |                                       |

       |                   PHY                 |

       +---------------------------------------+







Device discovery

================



OpenCAPI relies on a PCI-like configuration space, implemented on the

device. So the host can discover AFUs by querying the config space.



OpenCAPI devices in Linux are treated like PCI devices (with a few

caveats). The firmware is expected to abstract the hardware as if it

was a PCI link. A lot of the existing PCI infrastructure is reused:

devices are scanned and BARs are assigned during the standard PCI

enumeration. Commands like 'lspci' can therefore be used to see what

devices are available.



The configuration space defines the AFU(s) that can be found on the

physical adapter, such as its name, how many memory contexts it can

work with, the size of its MMIO areas, ...







MMIO

====



OpenCAPI defines two MMIO areas for each AFU:



* the global MMIO area, with registers pertinent to the whole AFU.

* a per-process MMIO area, which has a fixed size for each context.







AFU interrupts

==============



OpenCAPI includes the possibility for an AFU to send an interrupt to a

host process. It is done through a 'intrp_req' defined in the

Transaction Layer, specifying a 64-bit object handle which defines the

interrupt.



The driver allows a process to allocate an interrupt and obtain its

64-bit object handle, that can be passed to the AFU.







char devices

============



The driver creates one char device per AFU found on the physical

device. A physical device may have multiple functions and each

function can have multiple AFUs. At the time of this writing though,

it has only been tested with devices exporting only one AFU.



Char devices can be found in /dev/ocxl/ and are named as:

/dev/ocxl/<AFU name>.<location>.<index>



where <AFU name> is a max 20-character long name, as found in the

config space of the AFU.

<location> is added by the driver and can help distinguish devices

when a system has more than one instance of the same OpenCAPI device.

<index> is also to help distinguish AFUs in the unlikely case where a

device carries multiple copies of the same AFU.







Sysfs class

===========



An ocxl class is added for the devices representing the AFUs. See

/sys/class/ocxl. The layout is described in

Documentation/ABI/testing/sysfs-class-ocxl







User API

========



open

----



Based on the AFU definition found in the config space, an AFU may

support working with more than one memory context, in which case the

associated char device may be opened multiple times by different

processes.





ioctl

-----



OCXL_IOCTL_ATTACH:



  Attach the memory context of the calling process to the AFU so that

  the AFU can access its memory.



OCXL_IOCTL_IRQ_ALLOC:



  Allocate an AFU interrupt and return an identifier.



OCXL_IOCTL_IRQ_FREE:



  Free a previously allocated AFU interrupt.



OCXL_IOCTL_IRQ_SET_FD:



  Associate an event fd to an AFU interrupt so that the user process

  can be notified when the AFU sends an interrupt.





mmap

----



A process can mmap the per-process MMIO area for interactions with the

AFU.

Documentation/devicetree/booting-without-of.txt

+1 −1
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@@ -1309,7 +1309,7 @@ number and level/sense information. All interrupt children in an 
OpenPIC interrupt domain use 2 cells per interrupt in their interrupts

property.



The PCI bus binding specifies a #interrupt-cell value of 1 to encode

The PCI bus binding specifies a #interrupt-cells value of 1 to encode

which interrupt pin (INTA,INTB,INTC,INTD) is used.



2) interrupt-parent property

Documentation/filesystems/dax.txt

+0 −1
Original line number Diff line number Diff line
@@ -46,7 +46,6 @@ stall the CPU for an extended period, you should also not attempt to 
implement direct_access.



These block devices may be used for inspiration:

- axonram: Axon DDR2 device driver

- brd: RAM backed block device driver

- dcssblk: s390 dcss block device driver

- pmem: NVDIMM persistent memory driver

Documentation/ioctl/ioctl-number.txt

+1 −0
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@@ -326,6 +326,7 @@ Code Seq#(hex) Include File Comments 
0xB5	00-0F	uapi/linux/rpmsg.h	<mailto:linux-remoteproc@vger.kernel.org>

0xC0	00-0F	linux/usb/iowarrior.h

0xCA	00-0F	uapi/misc/cxl.h

0xCA	10-2F	uapi/misc/ocxl.h

0xCA	80-BF	uapi/scsi/cxlflash_ioctl.h

0xCB	00-1F	CBM serial IEC bus	in development:

					<mailto:michael.klein@puffin.lb.shuttle.de>

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