Add API "startSubsystemRestart" and callback function

In order to trigger subsystem restart to reload wlan firmware,
this change adds an API for framework and vendor HAL.
Meanwhile, create new callback function for subsystem restart instead of
 general callback "onFailure()".

Bug: 178126071
Test: vendor HAL can received API call
      subsystem restart will callback "onSubsystemRestart()"

Change-Id: If3dc84049a9171677ad281c9bcc67a44dc722bdb

wifi/1.5/IWifiChip.hal

@@ -303,4 +303,25 @@ interface IWifiChip extends @1.4::IWifiChip {
     getUsableChannels(WifiBand band, bitfield<WifiIfaceMode> ifaceModeMask,
             bitfield<UsableChannelFilter> filterMask)
         generates (WifiStatus status, vec<WifiUsableChannel> channels);
+
+    /**
+     * Trigger subsystem restart
+     *
+     * If the framework detects a problem (e.g. connection failure),
+     * it must call this function to attempt recovery.
+     *
+     * When the wifi HAL receiveds triggerSubsystemRestart(), it must restart
+     * the wlan subsystem, especially the wlan firmware.
+     *
+     * Regarding the callback function for subsystem restart, refer to documentation of
+     * |IWifiEventCallback.onSubsystemRestart| for details.
+     *
+     * @return status WifiStatus of the operation.
+     *         Possible status codes:
+     *         |WifiStatusCode.SUCCESS|,
+     *         |WifiStatusCode.ERROR_WIFI_CHIP_INVALID|,
+     *         |WifiStatusCode.ERROR_NOT_AVAILABLE|,
+     *         |WifiStatusCode.ERROR_UNKNOWN|
+     */
+    triggerSubsystemRestart() generates (WifiStatus status);
 };

wifi/1.5/IWifiEventCallback.hal

@@ -17,5 +17,12 @@
 package android.hardware.wifi@1.5;
 
 import @1.0::IWifiEventCallback;
+import @1.0::WifiStatus;
 
-interface IWifiEventCallback extends @1.0::IWifiEventCallback {};
+interface IWifiEventCallback extends @1.0::IWifiEventCallback {
+  /**
+    * Must be called when the Wi-Fi subsystem restart completes.
+    * Once this event is received, framework must fully reset the Wi-Fi stack state.
+    */
+  oneway onSubsystemRestart(WifiStatus status);
+};

wifi/1.5/default/wifi.cpp

@@ -131,7 +131,7 @@ WifiStatus Wifi::startInternal() {
                 WifiStatus wifi_status =
                     createWifiStatus(WifiStatusCode::ERROR_UNKNOWN, error);
                 for (const auto& callback : event_cb_handler_.getCallbacks()) {
-                    if (!callback->onFailure(wifi_status).isOk()) {
+                    if (!callback->onSubsystemRestart(wifi_status).isOk()) {
                         LOG(ERROR) << "Failed to invoke onFailure callback";
                     }
                 }

wifi/1.5/default/wifi_chip.cpp

@@ -747,6 +747,13 @@ Return<void> WifiChip::getUsableChannels(
                            ifaceModeMask, filterMask);
 }
 
+Return<void> WifiChip::triggerSubsystemRestart(
+    triggerSubsystemRestart_cb hidl_status_cb) {
+    return validateAndCall(this, WifiStatusCode::ERROR_WIFI_CHIP_INVALID,
+                           &WifiChip::triggerSubsystemRestartInternal,
+                           hidl_status_cb);
+}
+
 void WifiChip::invalidateAndRemoveAllIfaces() {
     invalidateAndClearBridgedApAll();
     invalidateAndClearAll(ap_ifaces_);
@@ -1522,6 +1529,11 @@ WifiChip::getUsableChannelsInternal(WifiBand band, uint32_t ifaceModeMask,
     return {createWifiStatus(WifiStatusCode::SUCCESS), hidl_usable_channels};
 }
 
+WifiStatus WifiChip::triggerSubsystemRestartInternal() {
+    auto legacy_status = legacy_hal_.lock()->triggerSubsystemRestart();
+    return createWifiStatusFromLegacyError(legacy_status);
+}
+
 WifiStatus WifiChip::handleChipConfiguration(
     /* NONNULL */ std::unique_lock<std::recursive_mutex>* lock,
     ChipModeId mode_id) {

wifi/1.5/default/wifi_chip.h

@@ -184,6 +184,8 @@ class WifiChip : public V1_5::IWifiChip {
         WifiBand band, hidl_bitfield<WifiIfaceMode> ifaceModeMask,
         hidl_bitfield<UsableChannelFilter> filterMask,
         getUsableChannels_cb _hidl_cb) override;
+    Return<void> triggerSubsystemRestart(
+        triggerSubsystemRestart_cb hidl_status_cb) override;
 
    private:
     void invalidateAndRemoveAllIfaces();
@@ -303,6 +305,7 @@ class WifiChip : public V1_5::IWifiChip {
     void invalidateAndClearBridgedApAll();
     void invalidateAndClearBridgedAp(const std::string& br_name);
     bool findUsingNameFromBridgedApInstances(const std::string& name);
+    WifiStatus triggerSubsystemRestartInternal();
 
     ChipId chip_id_;
     std::weak_ptr<legacy_hal::WifiLegacyHal> legacy_hal_;

wifi/1.5/default/wifi_legacy_hal.cpp

@@ -1676,6 +1676,10 @@ WifiLegacyHal::getUsableChannels(uint32_t band_mask, uint32_t iface_mode_mask,
     return {status, std::move(channels)};
 }
 
+wifi_error WifiLegacyHal::triggerSubsystemRestart() {
+    return global_func_table_.wifi_trigger_subsystem_restart();
+}
+
 void WifiLegacyHal::invalidate() {
     global_handle_ = nullptr;
     iface_name_to_handle_.clear();

wifi/1.5/default/wifi_legacy_hal.h

@@ -716,6 +716,8 @@ class WifiLegacyHal {
     std::pair<wifi_error, std::vector<wifi_usable_channel>> getUsableChannels(
         uint32_t band_mask, uint32_t iface_mode_mask, uint32_t filter_mask);
 
+    wifi_error triggerSubsystemRestart();
+
    private:
     // Retrieve interface handles for all the available interfaces.
     wifi_error retrieveIfaceHandles();

wifi/1.5/default/wifi_legacy_hal_stubs.cpp

@@ -160,6 +160,7 @@ bool initHalFuncTableWithStubs(wifi_hal_fn* hal_fn) {
     populateStubFor(&hal_fn->wifi_twt_clear_stats);
     populateStubFor(&hal_fn->wifi_set_dtim_config);
     populateStubFor(&hal_fn->wifi_get_usable_channels);
+    populateStubFor(&hal_fn->wifi_trigger_subsystem_restart);
     return true;
 }
 }  // namespace legacy_hal