staging: unisys: detect controlvm channel on module load

The controlvm channel is not removable from a guest after the guest starts,
so it makes no sense to constantly check for it. Move the channel address
discovery to visorchipset_init(), and remove all of the checks for the channel
address from the rest of the module, as the module will not load if the
channel pointer is not valid.

Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/unisys/visorchipset/visorchipset_main.c b/drivers/staging/unisys/visorchipset/visorchipset_main.c
index ea0fb64..a16d67e 100644 (file)
--- a/drivers/staging/unisys/visorchipset/visorchipset_main.c
+++ b/drivers/staging/unisys/visorchipset/visorchipset_main.c
@@ -576,8 +576,6 @@ static void
 controlvm_respond(CONTROLVM_MESSAGE_HEADER *msgHdr, int response)
 {
        CONTROLVM_MESSAGE outmsg;
-       if (!ControlVm_channel)
-               return;
        controlvm_init_response(&outmsg, msgHdr, response);
        /* For DiagPool channel DEVICE_CHANGESTATE, we need to send
        * back the deviceChangeState structure in the packet. */
@@ -604,8 +602,6 @@ controlvm_respond_chipset_init(CONTROLVM_MESSAGE_HEADER *msgHdr, int response,
                               ULTRA_CHIPSET_FEATURE features)
 {
        CONTROLVM_MESSAGE outmsg;
-       if (!ControlVm_channel)
-               return;
        controlvm_init_response(&outmsg, msgHdr, response);
        outmsg.cmd.initChipset.features = features;
        if (!visorchannel_signalinsert(ControlVm_channel,
@@ -620,8 +616,6 @@ controlvm_respond_physdev_changestate(CONTROLVM_MESSAGE_HEADER *msgHdr,
                                      int response, ULTRA_SEGMENT_STATE state)
 {
        CONTROLVM_MESSAGE outmsg;
-       if (!ControlVm_channel)
-               return;
        controlvm_init_response(&outmsg, msgHdr, response);
        outmsg.cmd.deviceChangeState.state = state;
        outmsg.cmd.deviceChangeState.flags.physicalDevice = 1;
@@ -739,9 +733,6 @@ device_changestate_responder(CONTROLVM_ID cmdId,
        VISORCHIPSET_DEVICE_INFO *p = NULL;
        CONTROLVM_MESSAGE outmsg;
 
-       if (!ControlVm_channel)
-               return;
-
        p = finddevice(&DevInfoList, busNo, devNo);
        if (!p) {
                LOGERR("internal error; busNo=%lu, devNo=%lu", busNo, devNo);
@@ -1855,7 +1846,6 @@ controlvm_periodic_work(struct work_struct *work)
 {
        VISORCHIPSET_CHANNEL_INFO chanInfo;
        CONTROLVM_MESSAGE inmsg;
-       char s[99];
        BOOL gotACommand = FALSE;
        BOOL handle_command_failed = FALSE;
        static U64 Poll_Count;
@@ -1870,32 +1860,9 @@ controlvm_periodic_work(struct work_struct *work)
                goto Away;
 
        memset(&chanInfo, 0, sizeof(VISORCHIPSET_CHANNEL_INFO));
-       if (!ControlVm_channel) {
-               HOSTADDRESS addr = controlvm_get_channel_address();
-               if (addr != 0) {
-                       ControlVm_channel =
-                           visorchannel_create_with_lock
-                           (addr,
-                            sizeof(ULTRA_CONTROLVM_CHANNEL_PROTOCOL),
-                            UltraControlvmChannelProtocolGuid);
-                       if (ControlVm_channel == NULL)
-                               LOGERR("failed to create controlvm channel");
-                       else if (ULTRA_CONTROLVM_CHANNEL_OK_CLIENT
-                                (visorchannel_get_header(ControlVm_channel),
-                                 NULL)) {
-                               LOGINF("Channel %s (ControlVm) discovered",
-                                      visorchannel_id(ControlVm_channel, s));
-                               initialize_controlvm_payload();
-                       } else {
-                               LOGERR("controlvm channel is invalid");
-                               visorchannel_destroy(ControlVm_channel);
-                               ControlVm_channel = NULL;
-                       }
-               }
-       }
 
        Poll_Count++;
-       if ((ControlVm_channel != NULL) || (Poll_Count >= 250))
+       if (Poll_Count >= 250)
                ;       /* keep going */
        else
                goto Away;
@@ -1914,54 +1881,46 @@ controlvm_periodic_work(struct work_struct *work)
                }
        }
 
-       if (ControlVm_channel) {
-               while (visorchannel_signalremove(ControlVm_channel,
-                                                CONTROLVM_QUEUE_RESPONSE,
-                                                &inmsg)) {
-                       if (inmsg.hdr.PayloadMaxBytes != 0) {
-                               LOGERR("Payload of size %lu returned @%lu with unexpected message id %d.",
-                                    (ulong) inmsg.hdr.PayloadMaxBytes,
-                                    (ulong) inmsg.hdr.PayloadVmOffset,
-                                    inmsg.hdr.Id);
-                       }
-               }
-               if (!gotACommand) {
-                       if (ControlVm_Pending_Msg_Valid) {
-                               /* we throttled processing of a prior
-                               * msg, so try to process it again
-                               * rather than reading a new one
-                               */
-                               inmsg = ControlVm_Pending_Msg;
-                               ControlVm_Pending_Msg_Valid = FALSE;
-                               gotACommand = TRUE;
-                       } else
-                               gotACommand = read_controlvm_event(&inmsg);
+       while (visorchannel_signalremove(ControlVm_channel,
+                                        CONTROLVM_QUEUE_RESPONSE,
+                                        &inmsg)) {
+               if (inmsg.hdr.PayloadMaxBytes != 0) {
+                       LOGERR("Payload of size %lu returned @%lu with unexpected message id %d.",
+                            (ulong) inmsg.hdr.PayloadMaxBytes,
+                            (ulong) inmsg.hdr.PayloadVmOffset,
+                            inmsg.hdr.Id);
                }
        }
+       if (!gotACommand) {
+               if (ControlVm_Pending_Msg_Valid) {
+                       /* we throttled processing of a prior
+                       * msg, so try to process it again
+                       * rather than reading a new one
+                       */
+                       inmsg = ControlVm_Pending_Msg;
+                       ControlVm_Pending_Msg_Valid = FALSE;
+                       gotACommand = TRUE;
+               } else
+                       gotACommand = read_controlvm_event(&inmsg);
+       }
 
        handle_command_failed = FALSE;
        while (gotACommand && (!handle_command_failed)) {
                Most_recent_message_jiffies = jiffies;
-               if (ControlVm_channel) {
-                       if (handle_command(inmsg,
-                                          visorchannel_get_physaddr
-                                          (ControlVm_channel)))
-                               gotACommand = read_controlvm_event(&inmsg);
-                       else {
-                               /* this is a scenario where throttling
-                               * is required, but probably NOT an
-                               * error...; we stash the current
-                               * controlvm msg so we will attempt to
-                               * reprocess it on our next loop
-                               */
-                               handle_command_failed = TRUE;
-                               ControlVm_Pending_Msg = inmsg;
-                               ControlVm_Pending_Msg_Valid = TRUE;
-                       }
-
-               } else {
-                       handle_command(inmsg, 0);
-                       gotACommand = FALSE;
+               if (handle_command(inmsg,
+                                  visorchannel_get_physaddr
+                                  (ControlVm_channel)))
+                       gotACommand = read_controlvm_event(&inmsg);
+               else {
+                       /* this is a scenario where throttling
+                       * is required, but probably NOT an
+                       * error...; we stash the current
+                       * controlvm msg so we will attempt to
+                       * reprocess it on our next loop
+                       */
+                       handle_command_failed = TRUE;
+                       ControlVm_Pending_Msg = inmsg;
+                       ControlVm_Pending_Msg_Valid = TRUE;
                }
        }
 
@@ -1998,7 +1957,6 @@ setup_crash_devices_work_queue(struct work_struct *work)
        CONTROLVM_MESSAGE localCrashCreateBusMsg;
        CONTROLVM_MESSAGE localCrashCreateDevMsg;
        CONTROLVM_MESSAGE msg;
-       HOSTADDRESS host_addr;
        U32 localSavedCrashMsgOffset;
        U16 localSavedCrashMsgCount;
 
@@ -2021,26 +1979,6 @@ setup_crash_devices_work_queue(struct work_struct *work)
 
        chipset_init(&msg);
 
-       host_addr = controlvm_get_channel_address();
-       if (!host_addr) {
-               LOGERR("Huh?  Host address is NULL");
-               POSTCODE_LINUX_2(CRASH_DEV_HADDR_NULL, POSTCODE_SEVERITY_ERR);
-               return;
-       }
-
-       ControlVm_channel =
-           visorchannel_create_with_lock
-           (host_addr,
-            sizeof(ULTRA_CONTROLVM_CHANNEL_PROTOCOL),
-            UltraControlvmChannelProtocolGuid);
-
-       if (ControlVm_channel == NULL) {
-               LOGERR("failed to create controlvm channel");
-               POSTCODE_LINUX_2(CRASH_DEV_CONTROLVM_NULL,
-                                POSTCODE_SEVERITY_ERR);
-               return;
-       }
-
        /* get saved message count */
        if (visorchannel_read(ControlVm_channel,
                              offsetof(ULTRA_CONTROLVM_CHANNEL_PROTOCOL,
@@ -2331,9 +2269,6 @@ proc_read_installer(struct file *file, char __user *buf,
        char *vbuf;
        loff_t pos = *offset;
 
-       if (!ControlVm_channel)
-               return -ENODEV;
-
        if (pos < 0)
                return -EINVAL;
 
@@ -2383,9 +2318,6 @@ proc_write_installer(struct file *file,
        U16 remainingSteps;
        U32 error, textId;
 
-       if (!ControlVm_channel)
-               return -ENODEV;
-
        /* Check to make sure there is no buffer overflow */
        if (count > (sizeof(buf) - 1))
                return -EINVAL;
@@ -2447,9 +2379,6 @@ proc_read_toolaction(struct file *file, char __user *buf,
        char *vbuf;
        loff_t pos = *offset;
 
-       if (!ControlVm_channel)
-               return -ENODEV;
-
        if (pos < 0)
                return -EINVAL;
 
@@ -2488,9 +2417,6 @@ proc_write_toolaction(struct file *file,
        char buf[3];
        U8 toolAction;
 
-       if (!ControlVm_channel)
-               return -ENODEV;
-
        /* Check to make sure there is no buffer overflow */
        if (count > (sizeof(buf) - 1))
                return -EINVAL;
@@ -2530,9 +2456,6 @@ proc_read_bootToTool(struct file *file, char __user *buf,
        char *vbuf;
        loff_t pos = *offset;
 
-       if (!ControlVm_channel)
-               return -ENODEV;
-
        if (pos < 0)
                return -EINVAL;
 
@@ -2571,9 +2494,6 @@ proc_write_bootToTool(struct file *file,
        int inputVal;
        ULTRA_EFI_SPAR_INDICATION efiSparIndication;
 
-       if (!ControlVm_channel)
-               return -ENODEV;
-
        /* Check to make sure there is no buffer overflow */
        if (count > (sizeof(buf) - 1))
                return -EINVAL;
@@ -2612,9 +2532,11 @@ static int __init
 visorchipset_init(void)
 {
        int rc = 0, x = 0;
+       char s[64];
        struct proc_dir_entry *installer_file;
        struct proc_dir_entry *toolaction_file;
        struct proc_dir_entry *bootToTool_file;
+       HOSTADDRESS addr;
 
        if (!unisys_spar_platform)
                return -ENODEV;
@@ -2646,6 +2568,30 @@ visorchipset_init(void)
                goto Away;
        }
 
+       addr = controlvm_get_channel_address();
+       if (addr != 0) {
+               ControlVm_channel =
+                   visorchannel_create_with_lock
+                   (addr,
+                    sizeof(ULTRA_CONTROLVM_CHANNEL_PROTOCOL),
+                    UltraControlvmChannelProtocolGuid);
+               if (ULTRA_CONTROLVM_CHANNEL_OK_CLIENT
+                        (visorchannel_get_header(ControlVm_channel),
+                         NULL)) {
+                       LOGINF("Channel %s (ControlVm) discovered",
+                              visorchannel_id(ControlVm_channel, s));
+                       initialize_controlvm_payload();
+               } else {
+                       LOGERR("controlvm channel is invalid");
+                       visorchannel_destroy(ControlVm_channel);
+                       ControlVm_channel = NULL;
+                       return -ENODEV;
+               }
+       } else {
+               LOGERR("no controlvm channel discovered");
+               return -ENODEV;
+       }
+
        MajorDev = MKDEV(visorchipset_major, 0);
        rc = visorchipset_file_init(MajorDev, &ControlVm_channel);
        if (rc < 0) {
@@ -2795,12 +2741,10 @@ visorchipset_exit(void)
        memset(&g_DelDumpMsgHdr, 0, sizeof(CONTROLVM_MESSAGE_HEADER));
 
        proc_DeInit();
-       if (ControlVm_channel != NULL) {
-               LOGINF("Channel %s (ControlVm) disconnected",
-                      visorchannel_id(ControlVm_channel, s));
-               visorchannel_destroy(ControlVm_channel);
-               ControlVm_channel = NULL;
-       }
+       LOGINF("Channel %s (ControlVm) disconnected",
+              visorchannel_id(ControlVm_channel, s));
+       visorchannel_destroy(ControlVm_channel);
+
        visorchipset_file_cleanup();
        POSTCODE_LINUX_2(DRIVER_EXIT_PC, POSTCODE_SEVERITY_INFO);
        LOGINF("chipset driver unloaded");