[PATCH char-misc-testing v2 8/8] misc: mic: MIC host and card driver changes to enable VOP

[Sudeep Dutt]

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@xxxxxxxxx>
Signed-off-by: Sudeep Dutt <sudeep.dutt@xxxxxxxxx>
---
 Documentation/mic/mic_overview.txt |  54 ++++++++--------
 drivers/misc/mic/Kconfig           |   7 ++-
 drivers/misc/mic/card/mic_device.h |   3 +
 drivers/misc/mic/host/mic_device.h |   3 +
 Documentation/mic/mpssd/mpssd.c    |   2 +-
 drivers/misc/mic/card/mic_device.c |  84 ++++++++++++++++++++++++-
 drivers/misc/mic/card/mic_x100.c   |   1 +
 drivers/misc/mic/host/mic_boot.c   | 123 ++++++++++++++++++++++++++++++++++++-
 drivers/misc/mic/host/mic_main.c   |   1 +
 Documentation/mic/mpssd/mpss       |   2 +-
 10 files changed, 247 insertions(+), 33 deletions(-)

diff --git a/Documentation/mic/mic_overview.txt b/Documentation/mic/mic_overview.txt
index 73f44fc..074adbd 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/drivers/misc/mic/Kconfig b/drivers/misc/mic/Kconfig
index b03bb17..2e4f3ba 100644
--- a/drivers/misc/mic/Kconfig
+++ b/drivers/misc/mic/Kconfig
@@ -53,8 +53,8 @@ comment "Intel MIC Host Driver"
 
 config INTEL_MIC_HOST
 	tristate "Intel MIC Host Driver"
-	depends on 64BIT && PCI && X86 && INTEL_MIC_BUS && SCIF_BUS && MIC_COSM
-	select VHOST_RING
+	depends on 64BIT && PCI && X86
+	depends on INTEL_MIC_BUS && SCIF_BUS && MIC_COSM && VOP_BUS
 	help
 	  This enables Host Driver support for the Intel Many Integrated
 	  Core (MIC) family of PCIe form factor coprocessor devices that
@@ -73,7 +73,8 @@ comment "Intel MIC Card Driver"
 
 config INTEL_MIC_CARD
 	tristate "Intel MIC Card Driver"
-	depends on 64BIT && X86 && INTEL_MIC_BUS && SCIF_BUS && MIC_COSM
+	depends on 64BIT && X86
+	depends on INTEL_MIC_BUS && SCIF_BUS && MIC_COSM && VOP_BUS
 	select VIRTIO
 	help
 	  This enables card driver support for the Intel Many Integrated
diff --git a/drivers/misc/mic/card/mic_device.h b/drivers/misc/mic/card/mic_device.h
index 1dbf83c..333dbed 100644
--- a/drivers/misc/mic/card/mic_device.h
+++ b/drivers/misc/mic/card/mic_device.h
@@ -32,6 +32,7 @@
 #include <linux/interrupt.h>
 #include <linux/mic_bus.h>
 #include "../bus/scif_bus.h"
+#include "../bus/vop_bus.h"
 
 /**
  * struct mic_intr_info - Contains h/w specific interrupt sources info
@@ -76,6 +77,7 @@ struct mic_device {
  * @dma_ch - Array of DMA channels
  * @num_dma_ch - Number of DMA channels available
  * @scdev: SCIF device on the SCIF virtual bus.
+ * @vpdev: Virtio over PCIe device on the VOP virtual bus.
  */
 struct mic_driver {
 	char name[20];
@@ -90,6 +92,7 @@ struct mic_driver {
 	struct dma_chan *dma_ch[MIC_MAX_DMA_CHAN];
 	int num_dma_ch;
 	struct scif_hw_dev *scdev;
+	struct vop_device *vpdev;
 };
 
 /**
diff --git a/drivers/misc/mic/host/mic_device.h b/drivers/misc/mic/host/mic_device.h
index 8460de1..52b12b2 100644
--- a/drivers/misc/mic/host/mic_device.h
+++ b/drivers/misc/mic/host/mic_device.h
@@ -29,6 +29,7 @@
 #include <linux/miscdevice.h>
 #include <linux/mic_bus.h>
 #include "../bus/scif_bus.h"
+#include "../bus/vop_bus.h"
 #include "../bus/cosm_bus.h"
 #include "mic_intr.h"
 
@@ -68,6 +69,7 @@ extern struct cosm_hw_ops cosm_hw_ops;
  * @dma_ch - Array of DMA channels
  * @num_dma_ch - Number of DMA channels available
  * @scdev: SCIF device on the SCIF virtual bus.
+ * @vpdev: Virtio over PCIe device on the VOP virtual bus.
  * @cosm_dev: COSM device
  */
 struct mic_device {
@@ -92,6 +94,7 @@ struct mic_device {
 	struct dma_chan *dma_ch[MIC_MAX_DMA_CHAN];
 	int num_dma_ch;
 	struct scif_hw_dev *scdev;
+	struct vop_device *vpdev;
 	struct cosm_device *cosm_dev;
 };
 
diff --git a/Documentation/mic/mpssd/mpssd.c b/Documentation/mic/mpssd/mpssd.c
index aaeafa1..518dece 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));
diff --git a/drivers/misc/mic/card/mic_device.c b/drivers/misc/mic/card/mic_device.c
index ff03c63..e749af4 100644
--- a/drivers/misc/mic/card/mic_device.c
+++ b/drivers/misc/mic/card/mic_device.c
@@ -249,12 +249,82 @@ static struct scif_hw_ops scif_hw_ops = {
 	.iounmap = ___mic_iounmap,
 };
 
+static inline struct mic_driver *vpdev_to_mdrv(struct vop_device *vpdev)
+{
+	return dev_get_drvdata(vpdev->dev.parent);
+}
+
+static struct mic_irq *
+__mic_request_irq(struct vop_device *vpdev,
+		  irqreturn_t (*func)(int irq, void *data),
+		   const char *name, void *data, int intr_src)
+{
+	return mic_request_card_irq(func, NULL, name, data, intr_src);
+}
+
+static void __mic_free_irq(struct vop_device *vpdev,
+			   struct mic_irq *cookie, void *data)
+{
+	return mic_free_card_irq(cookie, data);
+}
+
+static void __mic_ack_interrupt(struct vop_device *vpdev, int num)
+{
+	struct mic_driver *mdrv = vpdev_to_mdrv(vpdev);
+
+	mic_ack_interrupt(&mdrv->mdev);
+}
+
+static int __mic_next_db(struct vop_device *vpdev)
+{
+	return mic_next_card_db();
+}
+
+static void __iomem *__mic_get_remote_dp(struct vop_device *vpdev)
+{
+	struct mic_driver *mdrv = vpdev_to_mdrv(vpdev);
+
+	return mdrv->dp;
+}
+
+static void __mic_send_intr(struct vop_device *vpdev, int db)
+{
+	struct mic_driver *mdrv = vpdev_to_mdrv(vpdev);
+
+	mic_send_intr(&mdrv->mdev, db);
+}
+
+static void __iomem *__mic_ioremap(struct vop_device *vpdev,
+				   dma_addr_t pa, size_t len)
+{
+	struct mic_driver *mdrv = vpdev_to_mdrv(vpdev);
+
+	return mic_card_map(&mdrv->mdev, pa, len);
+}
+
+static void __mic_iounmap(struct vop_device *vpdev, void __iomem *va)
+{
+	struct mic_driver *mdrv = vpdev_to_mdrv(vpdev);
+
+	mic_card_unmap(&mdrv->mdev, va);
+}
+
+static struct vop_hw_ops vop_hw_ops = {
+	.request_irq = __mic_request_irq,
+	.free_irq = __mic_free_irq,
+	.ack_interrupt = __mic_ack_interrupt,
+	.next_db = __mic_next_db,
+	.get_remote_dp = __mic_get_remote_dp,
+	.send_intr = __mic_send_intr,
+	.ioremap = __mic_ioremap,
+	.iounmap = __mic_iounmap,
+};
+
 static int mic_request_dma_chans(struct mic_driver *mdrv)
 {
 	dma_cap_mask_t mask;
 	struct dma_chan *chan;
 
-	request_module("mic_x100_dma");
 	dma_cap_zero(mask);
 	dma_cap_set(DMA_MEMCPY, mask);
 
@@ -308,6 +378,13 @@ int __init mic_driver_init(struct mic_driver *mdrv)
 		rc = -ENODEV;
 		goto irq_uninit;
 	}
+	mdrv->vpdev = vop_register_device(mdrv->dev, VOP_DEV_TRNSP,
+					  NULL, &vop_hw_ops, 0,
+					  NULL, mdrv->dma_ch[0]);
+	if (IS_ERR(mdrv->vpdev)) {
+		rc = PTR_ERR(mdrv->vpdev);
+		goto dma_free;
+	}
 	bootparam = mdrv->dp;
 	node_id = ioread8(&bootparam->node_id);
 	mdrv->scdev = scif_register_device(mdrv->dev, MIC_SCIF_DEV,
@@ -317,11 +394,13 @@ int __init mic_driver_init(struct mic_driver *mdrv)
 					   mdrv->num_dma_ch, true);
 	if (IS_ERR(mdrv->scdev)) {
 		rc = PTR_ERR(mdrv->scdev);
-		goto dma_free;
+		goto vop_remove;
 	}
 	mic_create_card_debug_dir(mdrv);
 done:
 	return rc;
+vop_remove:
+	vop_unregister_device(mdrv->vpdev);
 dma_free:
 	mic_free_dma_chans(mdrv);
 irq_uninit:
@@ -342,6 +421,7 @@ void mic_driver_uninit(struct mic_driver *mdrv)
 {
 	mic_delete_card_debug_dir(mdrv);
 	scif_unregister_device(mdrv->scdev);
+	vop_unregister_device(mdrv->vpdev);
 	mic_free_dma_chans(mdrv);
 	mic_uninit_irq();
 	mic_dp_uninit();
diff --git a/drivers/misc/mic/card/mic_x100.c b/drivers/misc/mic/card/mic_x100.c
index b2958ce..b9f0710 100644
--- a/drivers/misc/mic/card/mic_x100.c
+++ b/drivers/misc/mic/card/mic_x100.c
@@ -326,6 +326,7 @@ static int __init mic_init(void)
 		goto done;
 	}
 
+	request_module("mic_x100_dma");
 	mic_init_card_debugfs();
 	ret = platform_device_register(&mic_platform_dev);
 	if (ret) {
diff --git a/drivers/misc/mic/host/mic_boot.c b/drivers/misc/mic/host/mic_boot.c
index 3df305f..8c91c99 100644
--- a/drivers/misc/mic/host/mic_boot.c
+++ b/drivers/misc/mic/host/mic_boot.c
@@ -25,10 +25,118 @@
 #include <linux/mic_common.h>
 #include <linux/mic_bus.h>
 #include "../bus/scif_bus.h"
+#include "../bus/vop_bus.h"
 #include "../common/mic_dev.h"
 #include "mic_device.h"
 #include "mic_smpt.h"
 
+static inline struct mic_device *vpdev_to_mdev(struct device *dev)
+{
+	return dev_get_drvdata(dev->parent);
+}
+
+static dma_addr_t
+_mic_dma_map_page(struct device *dev, struct page *page,
+		  unsigned long offset, size_t size,
+		  enum dma_data_direction dir, struct dma_attrs *attrs)
+{
+	void *va = phys_to_virt(page_to_phys(page)) + offset;
+	struct mic_device *mdev = vpdev_to_mdev(dev);
+
+	return mic_map_single(mdev, va, size);
+}
+
+static void _mic_dma_unmap_page(struct device *dev, dma_addr_t dma_addr,
+				size_t size, enum dma_data_direction dir,
+				struct dma_attrs *attrs)
+{
+	struct mic_device *mdev = vpdev_to_mdev(dev);
+
+	mic_unmap_single(mdev, dma_addr, size);
+}
+
+static const struct dma_map_ops _mic_dma_ops = {
+	.map_page = _mic_dma_map_page,
+	.unmap_page = _mic_dma_unmap_page,
+};
+
+static struct mic_irq *
+__mic_request_irq(struct vop_device *vpdev,
+		  irqreturn_t (*func)(int irq, void *data),
+		  const char *name, void *data, int intr_src)
+{
+	struct mic_device *mdev = vpdev_to_mdev(&vpdev->dev);
+
+	return mic_request_threaded_irq(mdev, func, NULL, name, data,
+					intr_src, MIC_INTR_DB);
+}
+
+static void __mic_free_irq(struct vop_device *vpdev,
+			   struct mic_irq *cookie, void *data)
+{
+	struct mic_device *mdev = vpdev_to_mdev(&vpdev->dev);
+
+	return mic_free_irq(mdev, cookie, data);
+}
+
+static void __mic_ack_interrupt(struct vop_device *vpdev, int num)
+{
+	struct mic_device *mdev = vpdev_to_mdev(&vpdev->dev);
+
+	mdev->ops->intr_workarounds(mdev);
+}
+
+static int __mic_next_db(struct vop_device *vpdev)
+{
+	struct mic_device *mdev = vpdev_to_mdev(&vpdev->dev);
+
+	return mic_next_db(mdev);
+}
+
+static void *__mic_get_dp(struct vop_device *vpdev)
+{
+	struct mic_device *mdev = vpdev_to_mdev(&vpdev->dev);
+
+	return mdev->dp;
+}
+
+static void __iomem *__mic_get_remote_dp(struct vop_device *vpdev)
+{
+	return NULL;
+}
+
+static void __mic_send_intr(struct vop_device *vpdev, int db)
+{
+	struct mic_device *mdev = vpdev_to_mdev(&vpdev->dev);
+
+	mdev->ops->send_intr(mdev, db);
+}
+
+static void __iomem *__mic_ioremap(struct vop_device *vpdev,
+				   dma_addr_t pa, size_t len)
+{
+	struct mic_device *mdev = vpdev_to_mdev(&vpdev->dev);
+
+	return mdev->aper.va + pa;
+}
+
+static void __mic_iounmap(struct vop_device *vpdev, void __iomem *va)
+{
+	/* nothing to do */
+}
+
+static struct vop_hw_ops vop_hw_ops = {
+	.request_irq = __mic_request_irq,
+	.free_irq = __mic_free_irq,
+	.ack_interrupt = __mic_ack_interrupt,
+	.next_db = __mic_next_db,
+	.get_dp = __mic_get_dp,
+	.get_remote_dp = __mic_get_remote_dp,
+	.send_intr = __mic_send_intr,
+	.ioremap = __mic_ioremap,
+	.iounmap = __mic_iounmap,
+};
+
 static inline struct mic_device *scdev_to_mdev(struct scif_hw_dev *scdev)
 {
 	return dev_get_drvdata(scdev->dev.parent);
@@ -314,7 +422,6 @@ static int mic_request_dma_chans(struct mic_device *mdev)
 	dma_cap_mask_t mask;
 	struct dma_chan *chan;
 
-	request_module("mic_x100_dma");
 	dma_cap_zero(mask);
 	dma_cap_set(DMA_MEMCPY, mask);
 
@@ -386,9 +493,18 @@ static int _mic_start(struct cosm_device *cdev, int id)
 		goto dma_free;
 	}
 
+	mdev->vpdev = vop_register_device(&mdev->pdev->dev,
+					  VOP_DEV_TRNSP, &_mic_dma_ops,
+					  &vop_hw_ops, id + 1, &mdev->aper,
+					  mdev->dma_ch[0]);
+	if (IS_ERR(mdev->vpdev)) {
+		rc = PTR_ERR(mdev->vpdev);
+		goto scif_remove;
+	}
+
 	rc = mdev->ops->load_mic_fw(mdev, NULL);
 	if (rc)
-		goto scif_remove;
+		goto vop_remove;
 	mic_smpt_restore(mdev);
 	mic_intr_restore(mdev);
 	mdev->intr_ops->enable_interrupts(mdev);
@@ -396,6 +512,8 @@ static int _mic_start(struct cosm_device *cdev, int id)
 	mdev->ops->write_spad(mdev, MIC_DPHI_SPAD, mdev->dp_dma_addr >> 32);
 	mdev->ops->send_firmware_intr(mdev);
 	goto unlock_ret;
+vop_remove:
+	vop_unregister_device(mdev->vpdev);
 scif_remove:
 	scif_unregister_device(mdev->scdev);
 dma_free:
@@ -422,6 +540,7 @@ static void _mic_stop(struct cosm_device *cdev, bool force)
 	 * will be the first to be registered and the last to be
 	 * unregistered.
 	 */
+	vop_unregister_device(mdev->vpdev);
 	scif_unregister_device(mdev->scdev);
 	mic_free_dma_chans(mdev);
 	mbus_unregister_device(mdev->dma_mbdev);
diff --git a/drivers/misc/mic/host/mic_main.c b/drivers/misc/mic/host/mic_main.c
index 400def2..035be3e 100644
--- a/drivers/misc/mic/host/mic_main.c
+++ b/drivers/misc/mic/host/mic_main.c
@@ -317,6 +317,7 @@ static int __init mic_init(void)
 {
 	int ret;
 
+	request_module("mic_x100_dma");
 	mic_init_debugfs();
 	ida_init(&g_mic_ida);
 	ret = pci_register_driver(&mic_driver);
diff --git a/Documentation/mic/mpssd/mpss b/Documentation/mic/mpssd/mpss
index 09ea9093..5fcf9fa 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()
 {
-- 
1.8.2.1