+++ /dev/null
-======================================================
-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 |
- +-------------------------------------------------------------+
projects / linux-2.6-microblaze.git / blobdiff