| Message ID | 20250107141015.3367194-20-rrichter@amd.com |
|---|---|
| State | New |
| Headers | show |
| Series | cxl: Add address translation support and enable AMD Zen5 platforms | expand |
On Tue, Jan 07, 2025 at 03:10:05PM +0100, Robert Richter wrote: > For the implementation of address translation it might not be possible > to determine the root decoder in the early enumeration state since the > SPA range is still unknown. Instead, the endpoint's HPA range is known > and from there the topology can be traversed up to the root port while > the memory range is adjusted from one memory domain to the next up to > the root port. > > In a first step, use endpoint's HPA range to find the port's decoder. > Without address translation there is HPA == SPA. Then, the HPA range > of the endpoint can be used instead of the root decoder's range as > both are the same. > > Signed-off-by: Robert Richter <rrichter@amd.com> I'll make a note to test up to this patch in particular in HPA==SPA mode without the follow ons. The functional change here is the move from cxlr->params to cxled->cxld.hpa_range. What was the likely value of cxlr->params previously? Undefined? Otherwise I don't immediately see any issues. Reviewed-by: Gregory Price <gourry@gourry.net> > --- > drivers/cxl/core/region.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index b7f6d8a83e4e..23b86de3d4e7 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -861,9 +861,8 @@ static int cxl_port_calc_hpa(struct cxl_port *port, struct cxl_decoder *cxld, > > static int match_auto_decoder(struct device *dev, void *data) > { > - struct cxl_region_params *p = data; > + struct range *r, *hpa = data; > struct cxl_decoder *cxld; > - struct range *r; > > if (!is_switch_decoder(dev)) > return 0; > @@ -871,7 +870,7 @@ static int match_auto_decoder(struct device *dev, void *data) > cxld = to_cxl_decoder(dev); > r = &cxld->hpa_range; > > - if (p->res && p->res->start == r->start && p->res->end == r->end) > + if (hpa && hpa->start == r->start && hpa->end == r->end) > return 1; > > return 0; > @@ -888,7 +887,7 @@ cxl_find_decoder_early(struct cxl_port *port, > return &cxled->cxld; > > if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags)) > - dev = device_find_child(&port->dev, &cxlr->params, > + dev = device_find_child(&port->dev, &cxled->cxld.hpa_range, > match_auto_decoder); > else > dev = device_find_child(&port->dev, NULL, match_free_decoder); > -- > 2.39.5 >
On 1/7/25 8:10 AM, Robert Richter wrote: > For the implementation of address translation it might not be possible > to determine the root decoder in the early enumeration state since the > SPA range is still unknown. Instead, the endpoint's HPA range is known > and from there the topology can be traversed up to the root port while > the memory range is adjusted from one memory domain to the next up to > the root port. > > In a first step, use endpoint's HPA range to find the port's decoder. > Without address translation there is HPA == SPA. Then, the HPA range > of the endpoint can be used instead of the root decoder's range as > both are the same. I think this can be clearer. Something like: "In a first step, use endpoint's HPA range to find the port's decoder. Without address translation HPA == SPA, so the endpoint's HPA range can be used since it is the same as the root decoder's. > > Signed-off-by: Robert Richter <rrichter@amd.com> > --- > drivers/cxl/core/region.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index b7f6d8a83e4e..23b86de3d4e7 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -861,9 +861,8 @@ static int cxl_port_calc_hpa(struct cxl_port *port, struct cxl_decoder *cxld, > > static int match_auto_decoder(struct device *dev, void *data) > { > - struct cxl_region_params *p = data; > + struct range *r, *hpa = data; > struct cxl_decoder *cxld; > - struct range *r; > > if (!is_switch_decoder(dev)) > return 0; > @@ -871,7 +870,7 @@ static int match_auto_decoder(struct device *dev, void *data) > cxld = to_cxl_decoder(dev); > r = &cxld->hpa_range; > > - if (p->res && p->res->start == r->start && p->res->end == r->end) > + if (hpa && hpa->start == r->start && hpa->end == r->end) > return 1; > > return 0; > @@ -888,7 +887,7 @@ cxl_find_decoder_early(struct cxl_port *port, > return &cxled->cxld; > > if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags)) > - dev = device_find_child(&port->dev, &cxlr->params, > + dev = device_find_child(&port->dev, &cxled->cxld.hpa_range, > match_auto_decoder); > else > dev = device_find_child(&port->dev, NULL, match_free_decoder);
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index b7f6d8a83e4e..23b86de3d4e7 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -861,9 +861,8 @@ static int cxl_port_calc_hpa(struct cxl_port *port, struct cxl_decoder *cxld, static int match_auto_decoder(struct device *dev, void *data) { - struct cxl_region_params *p = data; + struct range *r, *hpa = data; struct cxl_decoder *cxld; - struct range *r; if (!is_switch_decoder(dev)) return 0; @@ -871,7 +870,7 @@ static int match_auto_decoder(struct device *dev, void *data) cxld = to_cxl_decoder(dev); r = &cxld->hpa_range; - if (p->res && p->res->start == r->start && p->res->end == r->end) + if (hpa && hpa->start == r->start && hpa->end == r->end) return 1; return 0; @@ -888,7 +887,7 @@ cxl_find_decoder_early(struct cxl_port *port, return &cxled->cxld; if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags)) - dev = device_find_child(&port->dev, &cxlr->params, + dev = device_find_child(&port->dev, &cxled->cxld.hpa_range, match_auto_decoder); else dev = device_find_child(&port->dev, NULL, match_free_decoder);
For the implementation of address translation it might not be possible to determine the root decoder in the early enumeration state since the SPA range is still unknown. Instead, the endpoint's HPA range is known and from there the topology can be traversed up to the root port while the memory range is adjusted from one memory domain to the next up to the root port. In a first step, use endpoint's HPA range to find the port's decoder. Without address translation there is HPA == SPA. Then, the HPA range of the endpoint can be used instead of the root decoder's range as both are the same. Signed-off-by: Robert Richter <rrichter@amd.com> --- drivers/cxl/core/region.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)