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). We can't get around referencing this device from multiple files, can we? -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html