On 11/14/2017 12:00 PM, Cornelia Huck wrote:
On Tue, 14 Nov 2017 11:37:05 -0500
Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx> wrote:
On 11/14/2017 07:40 AM, Cornelia Huck wrote:
On Fri, 13 Oct 2017 13:38:50 -0400
Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx> wrote:
diff --git a/drivers/s390/crypto/ap_matrix_bus.c b/drivers/s390/crypto/ap_matrix_bus.c
index 4eb1e3c..66bfa54 100644
--- a/drivers/s390/crypto/ap_matrix_bus.c
+++ b/drivers/s390/crypto/ap_matrix_bus.c
@@ -75,10 +75,18 @@ static int ap_matrix_dev_create(void)
return 0;
}
+struct ap_matrix *ap_matrix_get_device(void)
+{
+ return matrix;
See the comments I had for the previous patch. In particular, I think
it is better to retrieve a pointer to the matrix device via driver core
methods.
I got some objections to creating a new bus and since there will only ever
be a single AP matrix device, I decided there really wasn't a need for an
AP matrix bus and got rid of it. I opted instead to create the matrix
device
in the init function of the vfio_ap_matrix driver. Rather than passing
around a
pointer, I put the following in vfio_ap_matrix_private.h:
struct ap_matrix {
struct device device;
spinlock_t qlock;
struct list_head queues;
};
extern struct ap_matrix ap_matrix;
... and declared the ap_matrix in the driver (vfio_ap_matrix_drv.c)
file as:
struct ap_matrix ap_matrix;
Does this seem like a reasonable approach?
Getting rid of the bus as overhead is not unreasonable.
I'm feeling a bit queasy about the extern, however. I'd prefer a getter
function (that also makes sure refcounting rules are followed).
I now think I can avoid having to reference the ap_matrix device from
multiple places. The reason the device is referenced in vfio_ap_matrix_ops.c
is because there is a need for information about the AP queues that have
been
bound to the vfio_ap_matrix device driver. If interfaces are provided by
the
vfio_ap_matrix device driver to access the needed information, it
won't be necessary to reference the ap_matrix device directly in
vfio_ap_matrix_ops. I think this would be a better solution, don't you?
We can't get around referencing this device from multiple files, can we?
The only way would be to roll up vfio_ap_matrix_ops.c into
vfio_ap_matrix_drv.c. I followed the pattern established
by the vfio_ccw
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