[Qemu-devel] [PATCH 7/9] pci/shpc: convert SHPC hotplug to use hotplug-handler API

[Igor Mammedov <imammedo@redhat.com>]

Split shpc_device_hotplug() into hotplug/unplug callbacks
and register them as "hotplug-handler" interface implementation of
PCI_BRIDGE_DEV device.

Replace pci_bus_hotplug() wiring with setting link on PCI BUS
"hotplug-handler" property to PCI_BRIDGE_DEV device.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
v2:
* drop error_is_set() and check local_error pointer directly
* keep original logic, i.e. do not abort in bridge init.
---
 hw/pci-bridge/pci_bridge_dev.c |    9 +++
 hw/pci/shpc.c                  |  127 +++++++++++++++++++++++++---------------
 include/hw/pci/shpc.h          |    8 +++
 3 files changed, 97 insertions(+), 47 deletions(-)

diff --git a/hw/pci-bridge/pci_bridge_dev.c b/hw/pci-bridge/pci_bridge_dev.c
index 440e187..e68145c 100644
--- a/hw/pci-bridge/pci_bridge_dev.c
+++ b/hw/pci-bridge/pci_bridge_dev.c
@@ -26,6 +26,7 @@
 #include "hw/pci/slotid_cap.h"
 #include "exec/memory.h"
 #include "hw/pci/pci_bus.h"
+#include "hw/hotplug.h"
 
 #define TYPE_PCI_BRIDGE_DEV "pci-bridge"
 #define PCI_BRIDGE_DEV(obj) \
@@ -136,6 +137,8 @@ static void pci_bridge_dev_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
+    HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
+
     k->init = pci_bridge_dev_initfn;
     k->exit = pci_bridge_dev_exitfn;
     k->config_write = pci_bridge_dev_write_config;
@@ -148,6 +151,8 @@ static void pci_bridge_dev_class_init(ObjectClass *klass, void *data)
     dc->props = pci_bridge_dev_properties;
     dc->vmsd = &pci_bridge_dev_vmstate;
     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
+    hc->plug = shpc_device_hotplug_cb;
+    hc->unplug = shpc_device_hot_unplug_cb;
 }
 
 static const TypeInfo pci_bridge_dev_info = {
@@ -155,6 +160,10 @@ static const TypeInfo pci_bridge_dev_info = {
     .parent        = TYPE_PCI_BRIDGE,
     .instance_size = sizeof(PCIBridgeDev),
     .class_init = pci_bridge_dev_class_init,
+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_HOTPLUG_HANDLER },
+        { }
+    }
 };
 
 static void pci_bridge_dev_register(void)
diff --git a/hw/pci/shpc.c b/hw/pci/shpc.c
index 576244b..df46280 100644
--- a/hw/pci/shpc.c
+++ b/hw/pci/shpc.c
@@ -7,6 +7,7 @@
 #include "hw/pci/pci.h"
 #include "hw/pci/pci_bus.h"
 #include "hw/pci/msi.h"
+#include "qapi/qmp/qerror.h"
 
 /* TODO: model power only and disabled slot states. */
 /* TODO: handle SERR and wakeups */
@@ -490,65 +491,93 @@ static const MemoryRegionOps shpc_mmio_ops = {
         .max_access_size = 4,
     },
 };
-
-static int shpc_device_hotplug(DeviceState *qdev, PCIDevice *affected_dev,
-                               PCIHotplugState hotplug_state)
+static void shpc_device_hotplug_common(PCIDevice *affected_dev, int *slot,
+                                       SHPCDevice *shpc, Error **errp)
 {
     int pci_slot = PCI_SLOT(affected_dev->devfn);
-    uint8_t state;
-    uint8_t led;
-    PCIDevice *d = DO_UPCAST(PCIDevice, qdev, qdev);
-    SHPCDevice *shpc = d->shpc;
-    int slot = SHPC_PCI_TO_IDX(pci_slot);
-    if (pci_slot < SHPC_IDX_TO_PCI(0) || slot >= shpc->nslots) {
-        error_report("Unsupported PCI slot %d for standard hotplug "
-                     "controller. Valid slots are between %d and %d.",
-                     pci_slot, SHPC_IDX_TO_PCI(0),
-                     SHPC_IDX_TO_PCI(shpc->nslots) - 1);
-        return -1;
+    *slot = SHPC_PCI_TO_IDX(pci_slot);
+
+    if (pci_slot < SHPC_IDX_TO_PCI(0) || *slot >= shpc->nslots) {
+        error_setg(errp, "Unsupported PCI slot %d for standard hotplug "
+                   "controller. Valid slots are between %d and %d.",
+                   pci_slot, SHPC_IDX_TO_PCI(0),
+                   SHPC_IDX_TO_PCI(shpc->nslots) - 1);
+        return;
+    }
+}
+
+void shpc_device_hotplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
+                            Error **errp)
+{
+    Error *local_err = NULL;
+    PCIDevice *pci_hotplug_dev = PCI_DEVICE(hotplug_dev);
+    SHPCDevice *shpc = pci_hotplug_dev->shpc;
+    int slot;
+
+    shpc_device_hotplug_common(PCI_DEVICE(dev), &slot, shpc, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
     }
+
     /* Don't send event when device is enabled during qemu machine creation:
      * it is present on boot, no hotplug event is necessary. We do send an
      * event when the device is disabled later. */
-    if (hotplug_state == PCI_COLDPLUG_ENABLED) {
+    if (!dev->hotplugged) {
         shpc_set_status(shpc, slot, 0, SHPC_SLOT_STATUS_MRL_OPEN);
         shpc_set_status(shpc, slot, SHPC_SLOT_STATUS_PRSNT_7_5W,
                         SHPC_SLOT_STATUS_PRSNT_MASK);
-        return 0;
+        return;
     }
-    if (hotplug_state == PCI_HOTPLUG_DISABLED) {
-        shpc->config[SHPC_SLOT_EVENT_LATCH(slot)] |= SHPC_SLOT_EVENT_BUTTON;
-        state = shpc_get_status(shpc, slot, SHPC_SLOT_STATE_MASK);
-        led = shpc_get_status(shpc, slot, SHPC_SLOT_PWR_LED_MASK);
-        if (state == SHPC_STATE_DISABLED && led == SHPC_LED_OFF) {
-            shpc_free_devices_in_slot(shpc, slot);
-            shpc_set_status(shpc, slot, 1, SHPC_SLOT_STATUS_MRL_OPEN);
-            shpc_set_status(shpc, slot, SHPC_SLOT_STATUS_PRSNT_EMPTY,
-                            SHPC_SLOT_STATUS_PRSNT_MASK);
-            shpc->config[SHPC_SLOT_EVENT_LATCH(slot)] |=
-                SHPC_SLOT_EVENT_MRL |
-                SHPC_SLOT_EVENT_PRESENCE;
-        }
+
+    /* This could be a cancellation of the previous removal.
+     * We check MRL state to figure out. */
+    if (shpc_get_status(shpc, slot, SHPC_SLOT_STATUS_MRL_OPEN)) {
+        shpc_set_status(shpc, slot, 0, SHPC_SLOT_STATUS_MRL_OPEN);
+        shpc_set_status(shpc, slot, SHPC_SLOT_STATUS_PRSNT_7_5W,
+                        SHPC_SLOT_STATUS_PRSNT_MASK);
+        shpc->config[SHPC_SLOT_EVENT_LATCH(slot)] |=
+            SHPC_SLOT_EVENT_BUTTON |
+            SHPC_SLOT_EVENT_MRL |
+            SHPC_SLOT_EVENT_PRESENCE;
     } else {
-        /* This could be a cancellation of the previous removal.
-         * We check MRL state to figure out. */
-        if (shpc_get_status(shpc, slot, SHPC_SLOT_STATUS_MRL_OPEN)) {
-            shpc_set_status(shpc, slot, 0, SHPC_SLOT_STATUS_MRL_OPEN);
-            shpc_set_status(shpc, slot, SHPC_SLOT_STATUS_PRSNT_7_5W,
-                            SHPC_SLOT_STATUS_PRSNT_MASK);
-            shpc->config[SHPC_SLOT_EVENT_LATCH(slot)] |=
-                SHPC_SLOT_EVENT_BUTTON |
-                SHPC_SLOT_EVENT_MRL |
-                SHPC_SLOT_EVENT_PRESENCE;
-        } else {
-            /* Press attention button to cancel removal */
-            shpc->config[SHPC_SLOT_EVENT_LATCH(slot)] |=
-                SHPC_SLOT_EVENT_BUTTON;
-        }
+        /* Press attention button to cancel removal */
+        shpc->config[SHPC_SLOT_EVENT_LATCH(slot)] |=
+            SHPC_SLOT_EVENT_BUTTON;
     }
     shpc_set_status(shpc, slot, 0, SHPC_SLOT_STATUS_66);
-    shpc_interrupt_update(d);
-    return 0;
+    shpc_interrupt_update(pci_hotplug_dev);
+}
+
+void shpc_device_hot_unplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
+                               Error **errp)
+{
+    Error *local_err = NULL;
+    PCIDevice *pci_hotplug_dev = PCI_DEVICE(hotplug_dev);
+    SHPCDevice *shpc = pci_hotplug_dev->shpc;
+    uint8_t state;
+    uint8_t led;
+    int slot;
+
+    shpc_device_hotplug_common(PCI_DEVICE(dev), &slot, shpc, errp);
+    if (local_err) {
+        return;
+    }
+
+    shpc->config[SHPC_SLOT_EVENT_LATCH(slot)] |= SHPC_SLOT_EVENT_BUTTON;
+    state = shpc_get_status(shpc, slot, SHPC_SLOT_STATE_MASK);
+    led = shpc_get_status(shpc, slot, SHPC_SLOT_PWR_LED_MASK);
+    if (state == SHPC_STATE_DISABLED && led == SHPC_LED_OFF) {
+        shpc_free_devices_in_slot(shpc, slot);
+        shpc_set_status(shpc, slot, 1, SHPC_SLOT_STATUS_MRL_OPEN);
+        shpc_set_status(shpc, slot, SHPC_SLOT_STATUS_PRSNT_EMPTY,
+                        SHPC_SLOT_STATUS_PRSNT_MASK);
+        shpc->config[SHPC_SLOT_EVENT_LATCH(slot)] |=
+            SHPC_SLOT_EVENT_MRL |
+            SHPC_SLOT_EVENT_PRESENCE;
+    }
+    shpc_set_status(shpc, slot, 0, SHPC_SLOT_STATUS_66);
+    shpc_interrupt_update(pci_hotplug_dev);
 }
 
 /* Initialize the SHPC structure in bridge's BAR. */
@@ -557,6 +586,7 @@ int shpc_init(PCIDevice *d, PCIBus *sec_bus, MemoryRegion *bar, unsigned offset)
     int i, ret;
     int nslots = SHPC_MAX_SLOTS; /* TODO: qdev property? */
     SHPCDevice *shpc = d->shpc = g_malloc0(sizeof(*d->shpc));
+    BusState *bus = BUS(sec_bus);
     shpc->sec_bus = sec_bus;
     ret = shpc_cap_add_config(d);
     if (ret) {
@@ -616,7 +646,10 @@ int shpc_init(PCIDevice *d, PCIBus *sec_bus, MemoryRegion *bar, unsigned offset)
                           d, "shpc-mmio", SHPC_SIZEOF(d));
     shpc_cap_update_dword(d);
     memory_region_add_subregion(bar, offset, &shpc->mmio);
-    pci_bus_hotplug(sec_bus, shpc_device_hotplug, &d->qdev);
+
+    bus->allow_hotplug = 1;
+    object_property_set_link(OBJECT(sec_bus), OBJECT(d),
+                             QDEV_HOTPLUG_HANDLER_PROPERTY, NULL);
 
     d->cap_present |= QEMU_PCI_CAP_SHPC;
     return 0;
diff --git a/include/hw/pci/shpc.h b/include/hw/pci/shpc.h
index 467911a..eef1a1a 100644
--- a/include/hw/pci/shpc.h
+++ b/include/hw/pci/shpc.h
@@ -4,6 +4,8 @@
 #include "qemu-common.h"
 #include "exec/memory.h"
 #include "migration/vmstate.h"
+#include "qapi/error.h"
+#include "hw/hotplug.h"
 
 struct SHPCDevice {
     /* Capability offset in device's config space */
@@ -41,6 +43,12 @@ int shpc_init(PCIDevice *dev, PCIBus *sec_bus, MemoryRegion *bar, unsigned off);
 void shpc_cleanup(PCIDevice *dev, MemoryRegion *bar);
 void shpc_cap_write_config(PCIDevice *d, uint32_t addr, uint32_t val, int len);
 
+
+void shpc_device_hotplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
+                            Error **errp);
+void shpc_device_hot_unplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
+                               Error **errp);
+
 extern VMStateInfo shpc_vmstate_info;
 #define SHPC_VMSTATE(_field, _type) \
     VMSTATE_BUFFER_UNSAFE_INFO(_field, _type, 0, shpc_vmstate_info, 0)
-- 
1.7.1