[PATCH v2 2/9] vfio/fsl-mc: Scan DPRC objects on vfio-fsl-mc driver bind

From: Diana Craciun
Date: Fri May 08 2020 - 03:20:52 EST


The DPRC (Data Path Resource Container) device is a bus device and has
child devices attached to it. When the vfio-fsl-mc driver is probed
the DPRC is scanned and the child devices discovered and initialized.

Signed-off-by: Bharat Bhushan <Bharat.Bhushan@xxxxxxx>
Signed-off-by: Diana Craciun <diana.craciun@xxxxxxxxxxx>
---
drivers/vfio/fsl-mc/vfio_fsl_mc.c | 106 ++++++++++++++++++++++
drivers/vfio/fsl-mc/vfio_fsl_mc_private.h | 1 +
2 files changed, 107 insertions(+)

diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
index 8b53c2a25b32..ea301ba81225 100644
--- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c
+++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
@@ -15,6 +15,8 @@

#include "vfio_fsl_mc_private.h"

+static struct fsl_mc_driver vfio_fsl_mc_driver;
+
static int vfio_fsl_mc_open(void *device_data)
{
if (!try_module_get(THIS_MODULE))
@@ -84,6 +86,69 @@ static const struct vfio_device_ops vfio_fsl_mc_ops = {
.mmap = vfio_fsl_mc_mmap,
};

+static int vfio_fsl_mc_bus_notifier(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct vfio_fsl_mc_device *vdev = container_of(nb,
+ struct vfio_fsl_mc_device, nb);
+ struct device *dev = data;
+ struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
+ struct fsl_mc_device *mc_cont = to_fsl_mc_device(mc_dev->dev.parent);
+
+ if (action == BUS_NOTIFY_ADD_DEVICE &&
+ vdev->mc_dev == mc_cont) {
+ mc_dev->driver_override = kasprintf(GFP_KERNEL, "%s",
+ vfio_fsl_mc_ops.name);
+ dev_info(dev, "Setting driver override for device in dprc %s\n",
+ dev_name(&mc_cont->dev));
+ } else if (action == BUS_NOTIFY_BOUND_DRIVER &&
+ vdev->mc_dev == mc_cont) {
+ struct fsl_mc_driver *mc_drv = to_fsl_mc_driver(dev->driver);
+
+ if (mc_drv && mc_drv != &vfio_fsl_mc_driver)
+ dev_warn(dev, "Object %s bound to driver %s while DPRC bound to vfio-fsl-mc\n",
+ dev_name(dev), mc_drv->driver.name);
+ }
+
+ return 0;
+}
+
+static int vfio_fsl_mc_init_device(struct vfio_fsl_mc_device *vdev)
+{
+ struct fsl_mc_device *mc_dev = vdev->mc_dev;
+ int ret = 0;
+
+ /* Non-dprc devices share mc_io from parent */
+ if (!is_fsl_mc_bus_dprc(mc_dev)) {
+ struct fsl_mc_device *mc_cont = to_fsl_mc_device(mc_dev->dev.parent);
+
+ mc_dev->mc_io = mc_cont->mc_io;
+ return 0;
+ }
+
+ vdev->nb.notifier_call = vfio_fsl_mc_bus_notifier;
+ ret = bus_register_notifier(&fsl_mc_bus_type, &vdev->nb);
+ if (ret)
+ return ret;
+
+ /* open DPRC, allocate a MC portal */
+ ret = dprc_setup(mc_dev);
+ if (ret < 0) {
+ dev_err(&mc_dev->dev, "Failed to setup DPRC (error = %d)\n", ret);
+ bus_unregister_notifier(&fsl_mc_bus_type, &vdev->nb);
+ return ret;
+ }
+
+ ret = dprc_scan_container(mc_dev, false);
+ if (ret < 0) {
+ dev_err(&mc_dev->dev, "Container scanning failed: %d\n", ret);
+ bus_unregister_notifier(&fsl_mc_bus_type, &vdev->nb);
+ dprc_cleanup(mc_dev);
+ }
+
+ return 0;
+}
+
static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
{
struct iommu_group *group;
@@ -112,9 +177,42 @@ static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
return ret;
}

+ ret = vfio_fsl_mc_init_device(vdev);
+ if (ret) {
+ vfio_iommu_group_put(group, dev);
+ return ret;
+ }
+
return ret;
}

+static int vfio_fsl_mc_device_remove(struct device *dev, void *data)
+{
+ struct fsl_mc_device *mc_dev;
+
+ WARN_ON(!dev);
+ mc_dev = to_fsl_mc_device(dev);
+ if (WARN_ON(!mc_dev))
+ return -ENODEV;
+
+ kfree(mc_dev->driver_override);
+ mc_dev->driver_override = NULL;
+
+ /*
+ * The device-specific remove callback will get invoked by device_del()
+ */
+ device_del(&mc_dev->dev);
+ put_device(&mc_dev->dev);
+
+ return 0;
+}
+
+static void vfio_fsl_mc_cleanup_dprc(struct fsl_mc_device *mc_dev)
+{
+ device_for_each_child(&mc_dev->dev, NULL, vfio_fsl_mc_device_remove);
+ dprc_cleanup(mc_dev);
+}
+
static int vfio_fsl_mc_remove(struct fsl_mc_device *mc_dev)
{
struct vfio_fsl_mc_device *vdev;
@@ -124,6 +222,14 @@ static int vfio_fsl_mc_remove(struct fsl_mc_device *mc_dev)
if (!vdev)
return -EINVAL;

+ if (vdev->nb.notifier_call)
+ bus_unregister_notifier(&fsl_mc_bus_type, &vdev->nb);
+
+ if (is_fsl_mc_bus_dprc(mc_dev))
+ vfio_fsl_mc_cleanup_dprc(vdev->mc_dev);
+
+ mc_dev->mc_io = NULL;
+
vfio_iommu_group_put(mc_dev->dev.iommu_group, dev);

return 0;
diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h b/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
index e79cc116f6b8..37d61eaa58c8 100644
--- a/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
+++ b/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
@@ -9,6 +9,7 @@

struct vfio_fsl_mc_device {
struct fsl_mc_device *mc_dev;
+ struct notifier_block nb;
};

#endif /* VFIO_FSL_MC_PRIVATE_H */
--
2.17.1