Messages in this thread | | | Date | Tue, 14 Nov 2017 18:00:36 +0100 | From | Cornelia Huck <> | Subject | Re: [RFC 05/19] s390/zcrypt: base implementation of AP matrix device driver |
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On Tue, 14 Nov 2017 11:37:05 -0500 Tony Krowiak <akrowiak@linux.vnet.ibm.com> wrote:
> On 11/14/2017 07:40 AM, Cornelia Huck wrote: > > On Fri, 13 Oct 2017 13:38:50 -0400 > > Tony Krowiak <akrowiak@linux.vnet.ibm.com> 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?
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