diff mbox series

[4/6] hw/pcie: Provide a utility function for control of EP / SW USP link

Message ID 20240916173518.1843023-5-Jonathan.Cameron@huawei.com
State New
Headers show
Series hw/cxl: Link speed and width control | expand

Commit Message

Jonathan Cameron Sept. 16, 2024, 5:35 p.m. UTC 
Whilst similar to existing PCIESlot link configuration a few registers
need to be set differently so that the downstream device presents
a 'configured' state that is then used to 'train' the upstream port
on the link.  Basically that means setting the status register to
reflect it succeeding in training up to target settings.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 include/hw/pci/pcie.h |  2 ++
 hw/pci/pcie.c         | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+)
diff mbox series

Patch

diff --git a/include/hw/pci/pcie.h b/include/hw/pci/pcie.h
index 5eddb90976..b8d59732bc 100644
--- a/include/hw/pci/pcie.h
+++ b/include/hw/pci/pcie.h
@@ -141,6 +141,8 @@  void pcie_acs_reset(PCIDevice *dev);
 void pcie_ari_init(PCIDevice *dev, uint16_t offset);
 void pcie_dev_ser_num_init(PCIDevice *dev, uint16_t offset, uint64_t ser_num);
 void pcie_ats_init(PCIDevice *dev, uint16_t offset, bool aligned);
+void pcie_cap_fill_link_ep_usp(PCIDevice *dev, PCIExpLinkWidth width,
+                               PCIExpLinkSpeed speed);
 
 void pcie_cap_slot_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
                                Error **errp);
diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index 1ac6d89dcf..2738dbb28d 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -154,6 +154,24 @@  static void pcie_cap_fill_lnk(uint8_t *exp_cap, PCIExpLinkWidth width,
     }
 }
 
+void pcie_cap_fill_link_ep_usp(PCIDevice *dev, PCIExpLinkWidth width,
+                               PCIExpLinkSpeed speed)
+{
+    uint8_t *exp_cap = dev->config + dev->exp.exp_cap;
+
+    /*
+     * For an end point or USP need to set the current status as well
+     * as the capabilities.
+     */
+    pci_long_test_and_clear_mask(exp_cap + PCI_EXP_LNKSTA,
+                                 PCI_EXP_LNKSTA_CLS | PCI_EXP_LNKSTA_NLW);
+    pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKSTA,
+                               QEMU_PCI_EXP_LNKSTA_NLW(width) |
+                               QEMU_PCI_EXP_LNKSTA_CLS(speed));
+
+    pcie_cap_fill_lnk(exp_cap, width, speed);
+}
+
 static void pcie_cap_fill_slot_lnk(PCIDevice *dev)
 {
     PCIESlot *s = (PCIESlot *)object_dynamic_cast(OBJECT(dev), TYPE_PCIE_SLOT);