| Message ID | 1442016439-7636-1-git-send-email-ddaney.cavm@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, Sep 12, 2015 at 01:07:19AM +0100, David Daney wrote: > From: David Daney <david.daney@cavium.com> > > The config space for external PCIe root complexes on some Cavium > ThunderX SoCs is very similar to CAM and ECAM, but differs in the > shift values that have to be applied to the bus and devfn numbers to > compose that address window offset. These root complexes also have > the interesting property that there is no root bridge, so the standard > manner of limiting scanning to only the first device doesn't work. We > can use the standard pci-host-generic driver if we make a minor > addition to handle these differences, so we... > > Add a mapping function for ThunderX PCIe root complexes with a bus > shift of 24 and devfn shift of 16. Ignore accesses for devices other > than the first device on the primary bus. > > Document the whole thing in devicetree/bindings/pci/host-generic-pci.txt > > Signed-off-by: David Daney <david.daney@cavium.com> > --- > > This patch depends on the set I recently sent: > https://lkml.org/lkml/2015/9/11/764 > > .../devicetree/bindings/pci/host-generic-pci.txt | 5 +++- > drivers/pci/host/pci-host-generic.c | 29 ++++++++++++++++++++++ > 2 files changed, 33 insertions(+), 1 deletion(-) > > diff --git a/Documentation/devicetree/bindings/pci/host-generic-pci.txt b/Documentation/devicetree/bindings/pci/host-generic-pci.txt > index daa6942..51cc1d1 100644 > --- a/Documentation/devicetree/bindings/pci/host-generic-pci.txt > +++ b/Documentation/devicetree/bindings/pci/host-generic-pci.txt > @@ -16,7 +16,10 @@ Properties of the host controller node: > > - compatible : Must be "pci-host-cam-generic" or "pci-host-ecam-generic" > depending on the layout of configuration space (CAM vs > - ECAM respectively). > + ECAM respectively). Also supported is > + "cavium,pci-host-thunder-pem" which has bus:devfn:reg in > + bits 24:16:0 respectively of the PCI config space address > + window. It's probably easier to read and maintain if we reword this as a list of property + comment rather than continue the freeform text. Other than that, I'm fine with special-casing your accessors if need-be. Will
diff --git a/Documentation/devicetree/bindings/pci/host-generic-pci.txt b/Documentation/devicetree/bindings/pci/host-generic-pci.txt index daa6942..51cc1d1 100644 --- a/Documentation/devicetree/bindings/pci/host-generic-pci.txt +++ b/Documentation/devicetree/bindings/pci/host-generic-pci.txt @@ -16,7 +16,10 @@ Properties of the host controller node: - compatible : Must be "pci-host-cam-generic" or "pci-host-ecam-generic" depending on the layout of configuration space (CAM vs - ECAM respectively). + ECAM respectively). Also supported is + "cavium,pci-host-thunder-pem" which has bus:devfn:reg in + bits 24:16:0 respectively of the PCI config space address + window. - device_type : Must be "pci". diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c index e0248b4..a392ba2 100644 --- a/drivers/pci/host/pci-host-generic.c +++ b/drivers/pci/host/pci-host-generic.c @@ -91,6 +91,32 @@ static struct gen_pci_cfg_bus_ops gen_pci_cfg_ecam_bus_ops = { } }; +static void __iomem *gen_pci_map_cfg_bus_thunder_pem(struct pci_bus *bus, + unsigned int devfn, + int where) +{ + struct gen_pci *pci = bus->sysdata; + resource_size_t idx = bus->number - pci->cfg.bus_range->start; + + /* + * Thunder PEM is a PCIe RC, but without a root bridge. On + * the primary bus, ignore accesses for devices other than + * the first device. + */ + if (idx == 0 && (devfn & ~7u)) + return NULL; + return pci->cfg.win[idx] + ((devfn << 16) | where); +} + +static struct gen_pci_cfg_bus_ops gen_pci_cfg_thunder_pem_bus_ops = { + .bus_shift = 24, + .ops = { + .map_bus = gen_pci_map_cfg_bus_thunder_pem, + .read = pci_generic_config_read, + .write = pci_generic_config_write, + } +}; + static const struct of_device_id gen_pci_of_match[] = { { .compatible = "pci-host-cam-generic", .data = &gen_pci_cfg_cam_bus_ops }, @@ -98,6 +124,9 @@ static const struct of_device_id gen_pci_of_match[] = { { .compatible = "pci-host-ecam-generic", .data = &gen_pci_cfg_ecam_bus_ops }, + { .compatible = "cavium,pci-host-thunder-pem", + .data = &gen_pci_cfg_thunder_pem_bus_ops }, + { }, }; MODULE_DEVICE_TABLE(of, gen_pci_of_match);