hw/pcie: Factor out PCI Express link register filling common to EP.

Whilst not all link related registers are common between RP / Switch DSP
and EP / Switch USP many of them are.  Factor that group out to save
on duplication when adding EP / Swtich USP configurability.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20240916173518.1843023-4-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 48 insertions, 39 deletions

diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index 4b2f080..1ac6d89 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -105,46 +105,18 @@ pcie_cap_v1_fill(PCIDevice *dev, uint8_t port, uint8_t type, uint8_t version)
     pci_set_word(cmask + PCI_EXP_LNKSTA, 0);
 }
 
-static void pcie_cap_fill_slot_lnk(PCIDevice *dev)
+/* Includes setting the target speed default */
+static void pcie_cap_fill_lnk(uint8_t *exp_cap, PCIExpLinkWidth width,
+                              PCIExpLinkSpeed speed)
 {
-    PCIESlot *s = (PCIESlot *)object_dynamic_cast(OBJECT(dev), TYPE_PCIE_SLOT);
-    uint8_t *exp_cap = dev->config + dev->exp.exp_cap;
-
-    /* Skip anything that isn't a PCIESlot */
-    if (!s) {
-        return;
-    }
-
     /* Clear and fill LNKCAP from what was configured above */
     pci_long_test_and_clear_mask(exp_cap + PCI_EXP_LNKCAP,
                                  PCI_EXP_LNKCAP_MLW | PCI_EXP_LNKCAP_SLS);
     pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP,
-                               QEMU_PCI_EXP_LNKCAP_MLW(s->width) |
-                               QEMU_PCI_EXP_LNKCAP_MLS(s->speed));
-
-    /*
-     * Link bandwidth notification is required for all root ports and
-     * downstream ports supporting links wider than x1 or multiple link
-     * speeds.
-     */
-    if (s->width > QEMU_PCI_EXP_LNK_X1 ||
-        s->speed > QEMU_PCI_EXP_LNK_2_5GT) {
-        pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP,
-                                   PCI_EXP_LNKCAP_LBNC);
-    }
-
-    if (s->speed > QEMU_PCI_EXP_LNK_2_5GT) {
-        /*
-         * Hot-plug capable downstream ports and downstream ports supporting
-         * link speeds greater than 5GT/s must hardwire PCI_EXP_LNKCAP_DLLLARC
-         * to 1b.  PCI_EXP_LNKCAP_DLLLARC implies PCI_EXP_LNKSTA_DLLLA, which
-         * we also hardwire to 1b here.  2.5GT/s hot-plug slots should also
-         * technically implement this, but it's not done here for compatibility.
-         */
-        pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP,
-                                   PCI_EXP_LNKCAP_DLLLARC);
-        /* the PCI_EXP_LNKSTA_DLLLA will be set in the hotplug function */
+                               QEMU_PCI_EXP_LNKCAP_MLW(width) |
+                               QEMU_PCI_EXP_LNKCAP_MLS(speed));
 
+    if (speed > QEMU_PCI_EXP_LNK_2_5GT) {
         /*
          * Target Link Speed defaults to the highest link speed supported by
          * the component.  2.5GT/s devices are permitted to hardwire to zero.
@@ -152,7 +124,7 @@ static void pcie_cap_fill_slot_lnk(PCIDevice *dev)
         pci_word_test_and_clear_mask(exp_cap + PCI_EXP_LNKCTL2,
                                      PCI_EXP_LNKCTL2_TLS);
         pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKCTL2,
-                                   QEMU_PCI_EXP_LNKCAP_MLS(s->speed) &
+                                   QEMU_PCI_EXP_LNKCAP_MLS(speed) &
                                    PCI_EXP_LNKCTL2_TLS);
     }
 
@@ -161,27 +133,64 @@ static void pcie_cap_fill_slot_lnk(PCIDevice *dev)
      * actually a reference to the highest bit supported in this register.
      * We assume the device supports all link speeds.
      */
-    if (s->speed > QEMU_PCI_EXP_LNK_5GT) {
+    if (speed > QEMU_PCI_EXP_LNK_5GT) {
         pci_long_test_and_clear_mask(exp_cap + PCI_EXP_LNKCAP2, ~0U);
         pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP2,
                                    PCI_EXP_LNKCAP2_SLS_2_5GB |
                                    PCI_EXP_LNKCAP2_SLS_5_0GB |
                                    PCI_EXP_LNKCAP2_SLS_8_0GB);
-        if (s->speed > QEMU_PCI_EXP_LNK_8GT) {
+        if (speed > QEMU_PCI_EXP_LNK_8GT) {
             pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP2,
                                        PCI_EXP_LNKCAP2_SLS_16_0GB);
         }
-        if (s->speed > QEMU_PCI_EXP_LNK_16GT) {
+        if (speed > QEMU_PCI_EXP_LNK_16GT) {
             pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP2,
                                        PCI_EXP_LNKCAP2_SLS_32_0GB);
         }
-        if (s->speed > QEMU_PCI_EXP_LNK_32GT) {
+        if (speed > QEMU_PCI_EXP_LNK_32GT) {
             pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP2,
                                        PCI_EXP_LNKCAP2_SLS_64_0GB);
         }
     }
 }
 
+static void pcie_cap_fill_slot_lnk(PCIDevice *dev)
+{
+    PCIESlot *s = (PCIESlot *)object_dynamic_cast(OBJECT(dev), TYPE_PCIE_SLOT);
+    uint8_t *exp_cap = dev->config + dev->exp.exp_cap;
+
+    /* Skip anything that isn't a PCIESlot */
+    if (!s) {
+        return;
+    }
+
+    /*
+     * Link bandwidth notification is required for all root ports and
+     * downstream ports supporting links wider than x1 or multiple link
+     * speeds.
+     */
+    if (s->width > QEMU_PCI_EXP_LNK_X1 ||
+        s->speed > QEMU_PCI_EXP_LNK_2_5GT) {
+        pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP,
+                                   PCI_EXP_LNKCAP_LBNC);
+    }
+
+    if (s->speed > QEMU_PCI_EXP_LNK_2_5GT) {
+        /*
+         * Hot-plug capable downstream ports and downstream ports supporting
+         * link speeds greater than 5GT/s must hardwire PCI_EXP_LNKCAP_DLLLARC
+         * to 1b.  PCI_EXP_LNKCAP_DLLLARC implies PCI_EXP_LNKSTA_DLLLA, which
+         * we also hardwire to 1b here.  2.5GT/s hot-plug slots should also
+         * technically implement this, but it's not done here for compatibility.
+         */
+        pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP,
+                                   PCI_EXP_LNKCAP_DLLLARC);
+        /* the PCI_EXP_LNKSTA_DLLLA will be set in the hotplug function */
+    }
+
+    pcie_cap_fill_lnk(exp_cap, s->width, s->speed);
+}
+
 int pcie_cap_init(PCIDevice *dev, uint8_t offset,
                   uint8_t type, uint8_t port,
                   Error **errp)