powerpc/pseries: Add shutdown() to vio_driver and vio_bus

Currently, neither the vio_bus or vio_driver structures provide support
for a shutdown() routine.

Add support for shutdown() by allowing drivers to provide a
implementation via function pointer in their vio_driver struct and
provide a proper implementation in the driver template for the vio_bus
that calls a vio drivers shutdown() if defined.

In the case that no shutdown() is defined by a vio driver and a kexec is
in progress we implement a big hammer that calls remove() to ensure no
further DMA for the devices is possible.

Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210402001325.939668-1-tyreld@linux.ibm.com
This commit is contained in:
Tyrel Datwyler 2021-04-01 18:13:25 -06:00 committed by Michael Ellerman
parent af31fd0c91
commit 39d0099f94
2 changed files with 17 additions and 0 deletions

View File

@ -114,6 +114,7 @@ struct vio_driver {
const struct vio_device_id *id_table;
int (*probe)(struct vio_dev *dev, const struct vio_device_id *id);
void (*remove)(struct vio_dev *dev);
void (*shutdown)(struct vio_dev *dev);
/* A driver must have a get_desired_dma() function to
* be loaded in a CMO environment if it uses DMA.
*/

View File

@ -22,6 +22,7 @@
#include <linux/mm.h>
#include <linux/dma-map-ops.h>
#include <linux/kobject.h>
#include <linux/kexec.h>
#include <asm/iommu.h>
#include <asm/dma.h>
@ -1278,6 +1279,20 @@ static int vio_bus_remove(struct device *dev)
return 0;
}
static void vio_bus_shutdown(struct device *dev)
{
struct vio_dev *viodev = to_vio_dev(dev);
struct vio_driver *viodrv;
if (dev->driver) {
viodrv = to_vio_driver(dev->driver);
if (viodrv->shutdown)
viodrv->shutdown(viodev);
else if (kexec_in_progress)
vio_bus_remove(dev);
}
}
/**
* vio_register_driver: - Register a new vio driver
* @viodrv: The vio_driver structure to be registered.
@ -1617,6 +1632,7 @@ struct bus_type vio_bus_type = {
.match = vio_bus_match,
.probe = vio_bus_probe,
.remove = vio_bus_remove,
.shutdown = vio_bus_shutdown,
};
/**