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authorLinus Torvalds <torvalds@linux-foundation.org>2018-02-02 10:01:04 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-02-02 10:01:04 -0800
commit03f51d4efa2287cc628bb20b0c032036d2a9e66a (patch)
treeec7fb3b6624d53092e2768578f3ef887c8d77f22 /Documentation
parentMerge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm (diff)
parentpowerpc/mm/radix: Fix build error when RADIX_MMU=n (diff)
downloadlinux-dev-03f51d4efa2287cc628bb20b0c032036d2a9e66a.tar.xz
linux-dev-03f51d4efa2287cc628bb20b0c032036d2a9e66a.zip
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 ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/testing/sysfs-class-ocxl35
-rw-r--r--Documentation/accelerators/ocxl.rst160
-rw-r--r--Documentation/devicetree/booting-without-of.txt2
-rw-r--r--Documentation/filesystems/dax.txt1
-rw-r--r--Documentation/ioctl/ioctl-number.txt1
5 files changed, 197 insertions, 2 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-ocxl b/Documentation/ABI/testing/sysfs-class-ocxl
new file mode 100644
index 000000000000..b5b1fa197592
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-ocxl
@@ -0,0 +1,35 @@
+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
diff --git a/Documentation/accelerators/ocxl.rst b/Documentation/accelerators/ocxl.rst
new file mode 100644
index 000000000000..4f7af841d935
--- /dev/null
+++ b/Documentation/accelerators/ocxl.rst
@@ -0,0 +1,160 @@
+========================================================
+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.
diff --git a/Documentation/devicetree/booting-without-of.txt b/Documentation/devicetree/booting-without-of.txt
index 417f91110010..e86bd2f64117 100644
--- a/Documentation/devicetree/booting-without-of.txt
+++ b/Documentation/devicetree/booting-without-of.txt
@@ -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
diff --git a/Documentation/filesystems/dax.txt b/Documentation/filesystems/dax.txt
index 3be3b266be41..70cb68bed2e8 100644
--- a/Documentation/filesystems/dax.txt
+++ b/Documentation/filesystems/dax.txt
@@ -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
diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
index 3e3fdae5f3ed..6501389d55b9 100644
--- a/Documentation/ioctl/ioctl-number.txt
+++ b/Documentation/ioctl/ioctl-number.txt
@@ -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>