pcie: add flr support

Support flr: trigger device reset on flr config write.
Signed-off-by: NIsaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

hw/pci.c

@@ -137,7 +137,11 @@ static void pci_update_irq_status(PCIDevice *dev)
     }
 }
 
-static void pci_device_reset(PCIDevice *dev)
+/*
+ * This function is called on #RST and FLR.
+ * FLR if PCI_EXP_DEVCTL_BCR_FLR is set
+ */
+void pci_device_reset(PCIDevice *dev)
 {
     int r;
     /* TODO: call the below unconditionally once all pci devices

hw/pci.h

@@ -237,6 +237,7 @@ void pci_bus_hotplug(PCIBus *bus, pci_hotplug_fn hotplug, DeviceState *dev);
 PCIBus *pci_register_bus(DeviceState *parent, const char *name,
                          pci_set_irq_fn set_irq, pci_map_irq_fn map_irq,
                          void *irq_opaque, int devfn_min, int nirq);
+void pci_device_reset(PCIDevice *dev);
 void pci_bus_reset(PCIBus *bus);
 
 void pci_bus_set_mem_base(PCIBus *bus, target_phys_addr_t base);

hw/pcie.c

@@ -380,10 +380,6 @@ void pcie_cap_root_reset(PCIDevice *dev)
     pci_set_word(dev->config + dev->exp.exp_cap + PCI_EXP_RTCTL, 0);
 }
 
-/*
- * TODO: implement FLR:
- * Right now sets the bit which indicates FLR is supported.
- */
 /* function level reset(FLR) */
 void pcie_cap_flr_init(PCIDevice *dev)
 {
@@ -403,8 +399,11 @@ void pcie_cap_flr_write_config(PCIDevice *dev,
                                uint32_t addr, uint32_t val, int len)
 {
     uint8_t *devctl = dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL;
-    if (pci_word_test_and_clear_mask(devctl, PCI_EXP_DEVCTL_BCR_FLR)) {
-        /* TODO: implement FLR */
+    if (pci_get_word(devctl) & PCI_EXP_DEVCTL_BCR_FLR) {
+        /* Clear PCI_EXP_DEVCTL_BCR_FLR after invoking the reset handler
+           so the handler can detect FLR by looking at this bit. */
+        pci_device_reset(dev);
+        pci_word_test_and_clear_mask(devctl, PCI_EXP_DEVCTL_BCR_FLR);
     }
 }
 

hw/pcie.h

@@ -63,8 +63,6 @@ struct PCIExpressDevice {
     /* Offset of express capability in config space */
     uint8_t exp_cap;
 
-    /* TODO FLR */
-
     /* SLOT */
     unsigned int hpev_intx;     /* INTx for hot plug event (0-3:INT[A-D]#)
                                  * default is 0 = INTA#

hw/xio3130_downstream.c

@@ -89,7 +89,7 @@ static int xio3130_downstream_initfn(PCIDevice *d)
     if (rc < 0) {
         goto err_msi;
     }
-    pcie_cap_flr_init(d);       /* TODO: implement FLR */
+    pcie_cap_flr_init(d);
     pcie_cap_deverr_init(d);
     pcie_cap_slot_init(d, s->slot);
     pcie_chassis_create(s->chassis);

hw/xio3130_upstream.c

@@ -85,10 +85,7 @@ static int xio3130_upstream_initfn(PCIDevice *d)
     if (rc < 0) {
         goto err_msi;
     }
-
-    /* TODO: implement FLR */
     pcie_cap_flr_init(d);
-
     pcie_cap_deverr_init(d);
     rc = pcie_aer_init(d, XIO3130_AER_OFFSET);
     if (rc < 0) {