misc: mic: MIC host and card driver changes to enable VOP

This patch modifies the MIC host and card drivers to start using the
VOP driver. The MIC host and card drivers now implement the VOP bus
operations and register a VOP device on the VOP bus. MIC driver stack
documentation is also updated to include the new VOP driver.

Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 32 insertions, 26 deletions

diff --git a/Documentation/mic/mic_overview.txt b/Documentation/mic/mic_overview.txt
index 73f44fc3e715..074adbdf83a4 100644
--- a/Documentation/mic/mic_overview.txt
+++ b/Documentation/mic/mic_overview.txt
@@ -12,10 +12,19 @@ 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.
+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
@@ -38,7 +47,6 @@ 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  |
                +----------+           |             +----------+
@@ -47,27 +55,25 @@ the fact that the virtio block storage backend can only be on the host.
         | Virtio| |Virtio  | |Virtio| | |Virtio   |  |Virtio  | |Virtio  |
         | Net   | |Console | |Block | | |Net      |  |Console | |Block   |
         | Driver| |Driver  | |Driver| | |backend  |  |backend | |backend |
-        +-------+ +--------+ +------+ | +---------+  +--------+ +--------+
+        +---+---+ +---+----+ +--+---+ | +---------+  +----+---+ +--------+
             |         |         |     |      |            |         |
             |         |         |     |User  |            |         |
-            |         |         |     |------|------------|---------|-------
-            +-------------------+     |Kernel +--------------------------+
-                      |               |       | Virtio over PCIe IOCTLs  |
-                      |               |       +--------------------------+
-+-----------+         |               |                   |  +-----------+
-| MIC DMA   |         |      +------+ | +------+ +------+ |  | MIC DMA   |
-| Driver    |         |      | SCIF | | | SCIF | | COSM | |  | Driver    |
-+-----------+         |      +------+ | +------+ +--+---+ |  +-----------+
-      |               |         |     |    |        |     |        |
-+---------------+     |      +------+ | +--+---+ +--+---+ | +----------------+
-|MIC virtual Bus|     |      |SCIF  | | |SCIF  | | COSM | | |MIC virtual Bus |
-+---------------+     |      |HW Bus| | |HW Bus| | Bus  | | +----------------+
-      |               |      +------+ | +--+---+ +------+ |              |
-      |               |         |     |       |     |     |              |
-      |   +-----------+---+     |     |       |    +---------------+     |
-      |   |Intel MIC      |     |     |       |    |Intel MIC      |     |
-      +---|Card Driver    |     |     |       |    |Host Driver    |     |
-          +------------+--------+     |       +----+---------------+-----+
+            |         |         |     |------|------------|--+------|-------
+            +---------+---------+     |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    |     |
+      +---+--------------+------+     |       +----+---------------+-----+
                  |                    |                   |
              +-------------------------------------------------------------+
              |                                                             |
diff --git a/Documentation/mic/mpssd/mpss b/Documentation/mic/mpssd/mpss
index 09ea90931649..5fcf9fa4b082 100755
--- a/Documentation/mic/mpssd/mpss
+++ b/Documentation/mic/mpssd/mpss
@@ -35,7 +35,7 @@
 
 exec=/usr/sbin/mpssd
 sysfs="/sys/class/mic"
-mic_modules="mic_host mic_x100_dma scif"
+mic_modules="mic_host mic_x100_dma scif vop"
 
 start()
 {
diff --git a/Documentation/mic/mpssd/mpssd.c b/Documentation/mic/mpssd/mpssd.c
index aaeafa18d99b..518dece71578 100644
--- a/Documentation/mic/mpssd/mpssd.c
+++ b/Documentation/mic/mpssd/mpssd.c
@@ -926,7 +926,7 @@ add_virtio_device(struct mic_info *mic, struct mic_device_desc *dd)
 	char path[PATH_MAX];
 	int fd, err;
 
-	snprintf(path, PATH_MAX, "/dev/mic%d", mic->id);
+	snprintf(path, PATH_MAX, "/dev/vop_virtio%d", mic->id);
 	fd = open(path, O_RDWR);
 	if (fd < 0) {
 		mpsslog("Could not open %s %s\n", path, strerror(errno));