Hi Eric,
On 9/3/2020 5:06 PM, Auger Eric wrote:
Hi Diana,
On 8/26/20 11:33 AM, Diana Craciun wrote:
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 | 84 +++++++++++++++++++++++
drivers/vfio/fsl-mc/vfio_fsl_mc_private.h | 1 +
2 files changed, 85 insertions(+)
diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
index 8b53c2a25b32..85e007be3a5d 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 +86,72 @@ 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);
+ if (!mc_dev->driver_override)
+ dev_warn(dev, "Setting driver override for device in dprc %s failed\n",
+ dev_name(&mc_cont->dev));
+ dev_info(dev, "Setting driver override for device in dprc %s\n",
+ dev_name(&mc_cont->dev));
Don't you miss an else here?
+ } 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;
+
+ /* 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) {
if (ret) here and in other places? or are there any > returned values
+ dev_err(&mc_dev->dev, "Failed to setup DPRC (error = %d)\n", ret);
nit: maybe align your error messages. Before you were using __func__,
here you don't. Maybe don't? also you may consider using strerror(-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);
+ dprc_cleanup(mc_dev);
I see dprc_cleanup is likely to fail. Generally cleanup shouldn't.
https://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg2283433.html
Right, I will change the dprc_cleanup not to fail.
+ bus_unregister_notifier(&fsl_mc_bus_type, &vdev->nb);
nit: here also you can factorize code doing goto unregister;
shouldn't you reset vdev->nb.notifier_call to NULL as well. I see it is
tested in other places.
+ }
+
+ return ret;
+}
+
static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
{
struct iommu_group *group;
@@ -112,6 +180,12 @@ static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
return ret;
}
+ ret = vfio_fsl_mc_init_device(vdev);
+ if (ret < 0) {
I think you also need to call vfio_del_group_dev(&pdev->dev)
+ vfio_iommu_group_put(group, dev);
+ return ret;
nit: goto put_group;
+ }
+
return ret;
}
@@ -124,6 +198,16 @@ 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)) {
+ dprc_remove_devices(mc_dev, NULL, 0);
+ dprc_cleanup(mc_dev);
+ }
you may consider doing the tear down in opposite order than
vfio_fsl_mc_init_device, ie. bus_unregister_notifier after the
dprc_cleanup? That's also what is done in vfio_fsl_mc_init_device error
path handling.
+
+ 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 */>
Thanks
Eric
Thanks,
Diana
