[Qemu-devel] [PATCH 2/2] pcie_aer: complete unwinding recursion

["Michael S. Tsirkin" <mst@redhat.com>]

Open-code functions created in the previous patch,
to make code more compact and clear.
Detcted and documented what looks like a bug in code
that becomes apparent from this refactoring.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/pcie_aer.c |   80 +++++++++++++++++++-------------------------------------
 1 files changed, 27 insertions(+), 53 deletions(-)

diff --git a/hw/pcie_aer.c b/hw/pcie_aer.c
index c565d39..6621918 100644
--- a/hw/pcie_aer.c
+++ b/hw/pcie_aer.c
@@ -215,33 +215,6 @@ pcie_aer_msg_alldev(PCIDevice *dev, const PCIEAERMsg *msg)
     return true;
 }
 
-/* Get parent port to send up error message on.
- * TODO: clean up and open-code this logic */
-static PCIDevice *pcie_aer_parent_port(PCIDevice *dev)
-{
-    PCIDevice *parent_port;
-    if (pci_is_express(dev) &&
-        pcie_cap_get_type(dev) == PCI_EXP_TYPE_ROOT_PORT) {
-        /* Root port can notify system itself,
-           or send the error message to root complex event collector. */
-        /*
-         * if root port is associated with an event collector,
-         * return the root complex event collector here.
-         * For now root complex event collector isn't supported.
-         */
-        parent_port = NULL;
-    } else {
-        parent_port = pci_bridge_get_device(dev->bus);
-    }
-    if (parent_port) {
-        if (!pci_is_express(parent_port)) {
-            /* just ignore it */
-            return NULL;
-        }
-    }
-    return parent_port;
-}
-
 /*
  * return value:
  * true: error message is sent up
@@ -381,41 +354,42 @@ static bool pcie_aer_msg_root_port(PCIDevice *dev, const PCIEAERMsg *msg)
 /*
  * 6.2.6 Error Message Control Figure 6-3
  *
- * Returns true in case the error needs to
- * be propagated up.
- * TODO: open-code.
+ * Walk up the bus tree from the device, propagate the error message.
  */
-static bool pcie_send_aer_msg(PCIDevice *dev, const PCIEAERMsg *msg)
+static void pcie_aer_msg(PCIDevice *dev, const PCIEAERMsg *msg)
 {
     uint8_t type;
-    bool msg_sent;
-
-    assert(pci_is_express(dev));
 
-    type = pcie_cap_get_type(dev);
-    if (type == PCI_EXP_TYPE_ROOT_PORT ||
-        type == PCI_EXP_TYPE_UPSTREAM ||
-        type == PCI_EXP_TYPE_DOWNSTREAM) {
-        msg_sent = pcie_aer_msg_vbridge(dev, msg);
-        if (!msg_sent) {
+    while (dev) {
+        if (!pci_is_express(parent_port)) {
+            /* just ignore it */
+            /* TODO: Shouldn't we set PCI_STATUS_SIG_SYSTEM_ERROR?
+             * Consider e.g. a PCI bridge above a PCI Express device. */
             return;
         }
-    }
-    msg_sent = pcie_aer_msg_alldev(dev, msg);
-    if (type == PCI_EXP_TYPE_ROOT_PORT && msg_sent) {
-        pcie_aer_msg_root_port(dev, msg);
-    }
-    return msg_sent;
-}
 
-static void pcie_aer_msg(PCIDevice *dev, const PCIEAERMsg *msg)
-{
-    bool send_to_parent;
-    while (dev) {
-        if (!pcie_send_aer_msg(dev, msg)) {
+        type = pcie_cap_get_type(dev);
+        if ((type == PCI_EXP_TYPE_ROOT_PORT ||
+            type == PCI_EXP_TYPE_UPSTREAM ||
+            type == PCI_EXP_TYPE_DOWNSTREAM) &&
+            !pcie_aer_msg_vbridge(dev, msg)) {
+                return;
+        }
+        if (!pcie_aer_msg_alldev(dev, msg)) {
+            return;
+        }
+        if (type == PCI_EXP_TYPE_ROOT_PORT) {
+            pcie_aer_msg_root_port(dev, msg);
+            /* Root port can notify system itself,
+               or send the error message to root complex event collector. */
+            /*
+             * if root port is associated with an event collector,
+             * return the root complex event collector here.
+             * For now root complex event collector isn't supported.
+             */
             return;
         }
-        dev =  pcie_aer_parent_port(dev);
+        dev = pci_bridge_get_device(dev->bus);
     }
 }
 
-- 
1.7.3.2.91.g446ac