From 84344ee2da1f8a23819c15361298d997d9e69dbf Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Mon, 27 Feb 2023 15:31:27 +0000 Subject: hw/pci: Add pcie_count_ds_port() and pcie_find_port_first() helpers These two helpers enable host bridges to operate differently depending on the number of downstream ports, in particular if there is only a single port. Useful for CXL where HDM address decoders are allowed to be implicit in the host bridge if there is only a single root port. Signed-off-by: Jonathan Cameron Message-Id: <20230227153128.8164-2-Jonathan.Cameron@huawei.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/pci/pcie_port.c | 38 ++++++++++++++++++++++++++++++++++++++ include/hw/pci/pcie_port.h | 2 ++ 2 files changed, 40 insertions(+) diff --git a/hw/pci/pcie_port.c b/hw/pci/pcie_port.c index 000633fec1..20ff2b39e8 100644 --- a/hw/pci/pcie_port.c +++ b/hw/pci/pcie_port.c @@ -161,6 +161,44 @@ PCIDevice *pcie_find_port_by_pn(PCIBus *bus, uint8_t pn) return NULL; } +/* Find first port in devfn number order */ +PCIDevice *pcie_find_port_first(PCIBus *bus) +{ + int devfn; + + for (devfn = 0; devfn < ARRAY_SIZE(bus->devices); devfn++) { + PCIDevice *d = bus->devices[devfn]; + + if (!d || !pci_is_express(d) || !d->exp.exp_cap) { + continue; + } + + if (object_dynamic_cast(OBJECT(d), TYPE_PCIE_PORT)) { + return d; + } + } + + return NULL; +} + +int pcie_count_ds_ports(PCIBus *bus) +{ + int dsp_count = 0; + int devfn; + + for (devfn = 0; devfn < ARRAY_SIZE(bus->devices); devfn++) { + PCIDevice *d = bus->devices[devfn]; + + if (!d || !pci_is_express(d) || !d->exp.exp_cap) { + continue; + } + if (object_dynamic_cast(OBJECT(d), TYPE_PCIE_PORT)) { + dsp_count++; + } + } + return dsp_count; +} + static bool pcie_slot_is_hotpluggbale_bus(HotplugHandler *plug_handler, BusState *bus) { diff --git a/include/hw/pci/pcie_port.h b/include/hw/pci/pcie_port.h index 6c40e3733f..90e6cf45b8 100644 --- a/include/hw/pci/pcie_port.h +++ b/include/hw/pci/pcie_port.h @@ -41,6 +41,8 @@ struct PCIEPort { void pcie_port_init_reg(PCIDevice *d); PCIDevice *pcie_find_port_by_pn(PCIBus *bus, uint8_t pn); +PCIDevice *pcie_find_port_first(PCIBus *bus); +int pcie_count_ds_ports(PCIBus *bus); #define TYPE_PCIE_SLOT "pcie-slot" OBJECT_DECLARE_SIMPLE_TYPE(PCIESlot, PCIE_SLOT) -- cgit v1.2.3