On Sat, 9 Jul 2022 20:55:17 -0700
Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> Jonathan Cameron wrote:
> > On Thu, 23 Jun 2022 19:47:07 -0700
> > Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> >
> > > The CXL specification enforces that endpoint decoders are committed in
> > > hw instance id order. In preparation for adding dynamic DPA allocation,
> > > record the hw instance id in endpoint decoders, and enforce allocations
> > > to occur in hw instance id order.
> > >
> > > Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> >
> > dpa_end isn't a good name given the value isn't a Device Physical Address.
> >
> > Otherwise looks fine,
> >
> > Jonathan
> >
> > > ---
> > > drivers/cxl/core/hdm.c | 14 ++++++++++++++
> > > drivers/cxl/core/port.c | 1 +
> > > drivers/cxl/cxl.h | 2 ++
> > > 3 files changed, 17 insertions(+)
> > >
> > > diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
> > > index 3f929231b822..8805afe63ebf 100644
> > > --- a/drivers/cxl/core/hdm.c
> > > +++ b/drivers/cxl/core/hdm.c
> > > @@ -153,6 +153,7 @@ static void __cxl_dpa_release(struct cxl_endpoint_decoder *cxled, bool remove_ac
> > > cxled->skip = 0;
> > > __release_region(&cxlds->dpa_res, res->start, resource_size(res));
> > > cxled->dpa_res = NULL;
> > > + port->dpa_end--;
> > > }
> > >
> > > static void cxl_dpa_release(void *cxled)
> > > @@ -183,6 +184,18 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled,
> > > return -EBUSY;
> > > }
> > >
> > > + if (port->dpa_end + 1 != cxled->cxld.id) {
> > > + /*
> > > + * Assumes alloc and commit order is always in hardware instance
> > > + * order per expectations from 8.2.5.12.20 Committing Decoder
> > > + * Programming that enforce decoder[m] committed before
> > > + * decoder[m+1] commit start.
> > > + */
> > > + dev_dbg(dev, "decoder%d.%d: expected decoder%d.%d\n", port->id,
> > > + cxled->cxld.id, port->id, port->dpa_end + 1);
> > > + return -EBUSY;
> > > + }
> > > +
> > > if (skip) {
> > > res = __request_region(&cxlds->dpa_res, base - skip, skip,
> > > dev_name(dev), 0);
> > > @@ -213,6 +226,7 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled,
> > > cxled->cxld.id, cxled->dpa_res);
> > > cxled->mode = CXL_DECODER_MIXED;
> > > }
> > > + port->dpa_end++;
> > >
> > > return 0;
> > > }
> > > diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
> > > index 9d632c8c580b..54bf032cbcb7 100644
> > > --- a/drivers/cxl/core/port.c
> > > +++ b/drivers/cxl/core/port.c
> > > @@ -485,6 +485,7 @@ static struct cxl_port *cxl_port_alloc(struct device *uport,
> > > port->uport = uport;
> > > port->component_reg_phys = component_reg_phys;
> > > ida_init(&port->decoder_ida);
> > > + port->dpa_end = -1;
> > > INIT_LIST_HEAD(&port->dports);
> > > INIT_LIST_HEAD(&port->endpoints);
> > >
> > > diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
> > > index aa223166f7ef..d8edbdaa6208 100644
> > > --- a/drivers/cxl/cxl.h
> > > +++ b/drivers/cxl/cxl.h
> > > @@ -326,6 +326,7 @@ struct cxl_nvdimm {
> > > * @dports: cxl_dport instances referenced by decoders
> > > * @endpoints: cxl_ep instances, endpoints that are a descendant of this port
> > > * @decoder_ida: allocator for decoder ids
> > > + * @dpa_end: cursor to track highest allocated decoder for allocation ordering
> >
> > dpa_end not a good name as this isn't a Device Physical Address.
>
> Ok, renamed it to 'hdm_end'. Suitable to add "Reviewed-by" now?
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Though I'll probably catch up with a later version when I've gotten through
more of my email and add it there as well so you don't have to add it
manually.
Thanks,
J
