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[PATCH v2 1/2] hw/pci: Add pcie_count_ds_port() and pcie_find_port_first
From: |
Jonathan Cameron |
Subject: |
[PATCH v2 1/2] hw/pci: Add pcie_count_ds_port() and pcie_find_port_first() helpers |
Date: |
Mon, 27 Feb 2023 15:31:27 +0000 |
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 <Jonathan.Cameron@huawei.com>
---
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 65a397ad23..1e9c485e5e 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 const TypeInfo pcie_port_type_info = {
.name = TYPE_PCIE_PORT,
.parent = TYPE_PCI_BRIDGE,
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)
--
2.37.2