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authorSudeep Dutt <sudeep.dutt@intel.com>2020-10-28 06:14:15 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-10-28 21:12:03 +0300
commit80ade22c06ca115b81dd168e99479c8e09843513 (patch)
treec9062baa446a55412b2dd7582778da381de1d302 /Documentation/misc-devices
parent3650b228f83adda7e5ee532e2b90429c03f7b9ec (diff)
downloadlinux-80ade22c06ca115b81dd168e99479c8e09843513.tar.xz
misc: mic: remove the MIC drivers
This patch removes the MIC drivers from the kernel tree since the corresponding devices have been discontinued. Removing the dma and char-misc changes in one patch and merging via the char-misc tree is best to avoid any potential build breakage. Cc: Nikhil Rao <nikhil.rao@intel.com> Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com> Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com> Acked-By: Vinod Koul <vkoul@kernel.org> Reviewed-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/8c1443136563de34699d2c084df478181c205db4.1603854416.git.sudeep.dutt@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/misc-devices')
-rw-r--r--Documentation/misc-devices/mic/index.rst16
-rw-r--r--Documentation/misc-devices/mic/mic_overview.rst85
-rw-r--r--Documentation/misc-devices/mic/scif_overview.rst108
3 files changed, 0 insertions, 209 deletions
diff --git a/Documentation/misc-devices/mic/index.rst b/Documentation/misc-devices/mic/index.rst
deleted file mode 100644
index 3a8d06367ef1..000000000000
--- a/Documentation/misc-devices/mic/index.rst
+++ /dev/null
@@ -1,16 +0,0 @@
-=============================================
-Intel Many Integrated Core (MIC) architecture
-=============================================
-
-.. toctree::
- :maxdepth: 1
-
- mic_overview
- scif_overview
-
-.. only:: subproject and html
-
- Indices
- =======
-
- * :ref:`genindex`
diff --git a/Documentation/misc-devices/mic/mic_overview.rst b/Documentation/misc-devices/mic/mic_overview.rst
deleted file mode 100644
index 17d956bdaf7c..000000000000
--- a/Documentation/misc-devices/mic/mic_overview.rst
+++ /dev/null
@@ -1,85 +0,0 @@
-======================================================
-Intel Many Integrated Core (MIC) architecture overview
-======================================================
-
-An Intel MIC X100 device is a PCIe form factor add-in coprocessor
-card based on the Intel Many Integrated Core (MIC) architecture
-that runs a Linux OS. It is a PCIe endpoint in a platform and therefore
-implements the three required standard address spaces i.e. configuration,
-memory and I/O. The host OS loads a device driver as is typical for
-PCIe devices. The card itself runs a bootstrap after reset that
-transfers control to the card OS downloaded from the host driver. The
-host driver supports OSPM suspend and resume operations. It shuts down
-the card during suspend and reboots the card OS during resume.
-The card OS as shipped by Intel is a Linux kernel with modifications
-for the X100 devices.
-
-Since it is a PCIe card, it does not have the ability to host hardware
-devices for networking, storage and console. We provide these devices
-on X100 coprocessors thus enabling a self-bootable equivalent
-environment for applications. A key benefit of our solution is that it
-leverages the standard virtio framework for network, disk and console
-devices, though in our case the virtio framework is used across a PCIe
-bus. A Virtio Over PCIe (VOP) driver allows creating user space
-backends or devices on the host which are used to probe virtio drivers
-for these devices on the MIC card. The existing VRINGH infrastructure
-in the kernel is used to access virtio rings from the host. The card
-VOP driver allows card virtio drivers to communicate with their user
-space backends on the host via a device page. Ring 3 apps on the host
-can add, remove and configure virtio devices. A thin MIC specific
-virtio_config_ops is implemented which is borrowed heavily from
-previous similar implementations in lguest and s390.
-
-MIC PCIe card has a dma controller with 8 channels. These channels are
-shared between the host s/w and the card s/w. 0 to 3 are used by host
-and 4 to 7 by card. As the dma device doesn't show up as PCIe device,
-a virtual bus called mic bus is created and virtual dma devices are
-created on it by the host/card drivers. On host the channels are private
-and used only by the host driver to transfer data for the virtio devices.
-
-The Symmetric Communication Interface (SCIF (pronounced as skiff)) is a
-low level communications API across PCIe currently implemented for MIC.
-More details are available at scif_overview.txt.
-
-The Coprocessor State Management (COSM) driver on the host allows for
-boot, shutdown and reset of Intel MIC devices. It communicates with a COSM
-"client" driver on the MIC cards over SCIF to perform these functions.
-
-Here is a block diagram of the various components described above. The
-virtio backends are situated on the host rather than the card given better
-single threaded performance for the host compared to MIC, the ability of
-the host to initiate DMA's to/from the card using the MIC DMA engine and
-the fact that the virtio block storage backend can only be on the host::
-
- +----------+ | +----------+
- | Card OS | | | Host OS |
- +----------+ | +----------+
- |
- +-------+ +--------+ +------+ | +---------+ +--------+ +--------+
- | Virtio| |Virtio | |Virtio| | |Virtio | |Virtio | |Virtio |
- | Net | |Console | |Block | | |Net | |Console | |Block |
- | Driver| |Driver | |Driver| | |backend | |backend | |backend |
- +---+---+ +---+----+ +--+---+ | +---------+ +----+---+ +--------+
- | | | | | | |
- | | | |User | | |
- | | | |------|------------|--+------|-------
- +---------+---------+ |Kernel |
- | | |
- +---------+ +---+----+ +------+ | +------+ +------+ +--+---+ +-------+
- |MIC DMA | | VOP | | SCIF | | | SCIF | | COSM | | VOP | |MIC DMA|
- +---+-----+ +---+----+ +--+---+ | +--+---+ +--+---+ +------+ +----+--+
- | | | | | | |
- +---+-----+ +---+----+ +--+---+ | +--+---+ +--+---+ +------+ +----+--+
- |MIC | | VOP | |SCIF | | |SCIF | | COSM | | VOP | | MIC |
- |HW Bus | | HW Bus| |HW Bus| | |HW Bus| | Bus | |HW Bus| |HW Bus |
- +---------+ +--------+ +--+---+ | +--+---+ +------+ +------+ +-------+
- | | | | | | |
- | +-----------+--+ | | | +---------------+ |
- | |Intel MIC | | | | |Intel MIC | |
- | |Card Driver | | | | |Host Driver | |
- +---+--------------+------+ | +----+---------------+-----+
- | | |
- +-------------------------------------------------------------+
- | |
- | PCIe Bus |
- +-------------------------------------------------------------+
diff --git a/Documentation/misc-devices/mic/scif_overview.rst b/Documentation/misc-devices/mic/scif_overview.rst
deleted file mode 100644
index 4c8ad9e43706..000000000000
--- a/Documentation/misc-devices/mic/scif_overview.rst
+++ /dev/null
@@ -1,108 +0,0 @@
-========================================
-Symmetric Communication Interface (SCIF)
-========================================
-
-The Symmetric Communication Interface (SCIF (pronounced as skiff)) is a low
-level communications API across PCIe currently implemented for MIC. Currently
-SCIF provides inter-node communication within a single host platform, where a
-node is a MIC Coprocessor or Xeon based host. SCIF abstracts the details of
-communicating over the PCIe bus while providing an API that is symmetric
-across all the nodes in the PCIe network. An important design objective for SCIF
-is to deliver the maximum possible performance given the communication
-abilities of the hardware. SCIF has been used to implement an offload compiler
-runtime and OFED support for MPI implementations for MIC coprocessors.
-
-SCIF API Components
-===================
-
-The SCIF API has the following parts:
-
-1. Connection establishment using a client server model
-2. Byte stream messaging intended for short messages
-3. Node enumeration to determine online nodes
-4. Poll semantics for detection of incoming connections and messages
-5. Memory registration to pin down pages
-6. Remote memory mapping for low latency CPU accesses via mmap
-7. Remote DMA (RDMA) for high bandwidth DMA transfers
-8. Fence APIs for RDMA synchronization
-
-SCIF exposes the notion of a connection which can be used by peer processes on
-nodes in a SCIF PCIe "network" to share memory "windows" and to communicate. A
-process in a SCIF node initiates a SCIF connection to a peer process on a
-different node via a SCIF "endpoint". SCIF endpoints support messaging APIs
-which are similar to connection oriented socket APIs. Connected SCIF endpoints
-can also register local memory which is followed by data transfer using either
-DMA, CPU copies or remote memory mapping via mmap. SCIF supports both user and
-kernel mode clients which are functionally equivalent.
-
-SCIF Performance for MIC
-========================
-
-DMA bandwidth comparison between the TCP (over ethernet over PCIe) stack versus
-SCIF shows the performance advantages of SCIF for HPC applications and
-runtimes::
-
- Comparison of TCP and SCIF based BW
-
- Throughput (GB/sec)
- 8 + PCIe Bandwidth ******
- + TCP ######
- 7 + ************************************** SCIF %%%%%%
- | %%%%%%%%%%%%%%%%%%%
- 6 + %%%%
- | %%
- | %%%
- 5 + %%
- | %%
- 4 + %%
- | %%
- 3 + %%
- | %
- 2 + %%
- | %%
- | %
- 1 +
- + ######################################
- 0 +++---+++--+--+-+--+--+-++-+--+-++-+--+-++-+-
- 1 10 100 1000 10000 100000
- Transfer Size (KBytes)
-
-SCIF allows memory sharing via mmap(..) between processes on different PCIe
-nodes and thus provides bare-metal PCIe latency. The round trip SCIF mmap
-latency from the host to an x100 MIC for an 8 byte message is 0.44 usecs.
-
-SCIF has a user space library which is a thin IOCTL wrapper providing a user
-space API similar to the kernel API in scif.h. The SCIF user space library
-is distributed @ https://software.intel.com/en-us/mic-developer
-
-Here is some pseudo code for an example of how two applications on two PCIe
-nodes would typically use the SCIF API::
-
- Process A (on node A) Process B (on node B)
-
- /* get online node information */
- scif_get_node_ids(..) scif_get_node_ids(..)
- scif_open(..) scif_open(..)
- scif_bind(..) scif_bind(..)
- scif_listen(..)
- scif_accept(..) scif_connect(..)
- /* SCIF connection established */
-
- /* Send and receive short messages */
- scif_send(..)/scif_recv(..) scif_send(..)/scif_recv(..)
-
- /* Register memory */
- scif_register(..) scif_register(..)
-
- /* RDMA */
- scif_readfrom(..)/scif_writeto(..) scif_readfrom(..)/scif_writeto(..)
-
- /* Fence DMAs */
- scif_fence_signal(..) scif_fence_signal(..)
-
- mmap(..) mmap(..)
-
- /* Access remote registered memory */
-
- /* Close the endpoints */
- scif_close(..) scif_close(..)