[SCSI] fcoe: Use per-CPU kernel function for dev_stats instead of an array

Remove the hotplug creation of dev_stats, we allocate for all possible CPUs
now when we allocate the lport.

v2: Durring the 2.6.30 merge window, before these patches were comitted,
'percpu_ptr' was renamed 'per_cpu_ptr'. This latest update updates this
patch for the name change.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

4 files changed, 31 insertions, 144 deletions

diff --git a/drivers/scsi/fcoe/fcoe_sw.c b/drivers/scsi/fcoe/fcoe_sw.c
index 2bbbe3c0cc7b..a6753903fd40 100644
--- a/drivers/scsi/fcoe/fcoe_sw.c
+++ b/drivers/scsi/fcoe/fcoe_sw.c
@@ -113,8 +113,6 @@ static struct scsi_host_template fcoe_sw_shost_template = {
  */
 static int fcoe_sw_lport_config(struct fc_lport *lp)
 {
-        int i = 0;
-
         lp->link_up = 0;
         lp->qfull = 0;
         lp->max_retry_count = 3;
@@ -123,12 +121,7 @@ static int fcoe_sw_lport_config(struct fc_lport *lp)
         lp->service_params = (FCP_SPPF_INIT_FCN | FCP_SPPF_RD_XRDY_DIS |
                               FCP_SPPF_RETRY | FCP_SPPF_CONF_COMPL);
 
-        /*
-         * allocate per cpu stats block
-         */
-        for_each_online_cpu(i)
-                lp->dev_stats[i] = kzalloc(sizeof(struct fcoe_dev_stats),
-                                           GFP_KERNEL);
+        fc_lport_init_stats(lp);
 
         /* lport fc_lport related configuration */
         fc_lport_config(lp);
@@ -311,7 +304,6 @@ static inline int fcoe_sw_em_config(struct fc_lport *lp)
  */
 static int fcoe_sw_destroy(struct net_device *netdev)
 {
-        int cpu;
         struct fc_lport *lp = NULL;
         struct fcoe_softc *fc;
         u8 flogi_maddr[ETH_ALEN];
@@ -363,8 +355,7 @@ static int fcoe_sw_destroy(struct net_device *netdev)
         fcoe_clean_pending_queue(lp);
 
         /* Free memory used by statistical counters */
-        for_each_online_cpu(cpu)
-                kfree(lp->dev_stats[cpu]);
+        fc_lport_free_stats(lp);
 
         /* Release the net_device and Scsi_Host */
         dev_put(fc->real_dev);
diff --git a/drivers/scsi/fcoe/libfcoe.c b/drivers/scsi/fcoe/libfcoe.c
index d22275bf57f8..648a2fc04271 100644
--- a/drivers/scsi/fcoe/libfcoe.c
+++ b/drivers/scsi/fcoe/libfcoe.c
@@ -71,9 +71,6 @@ DEFINE_PER_CPU(struct fcoe_percpu_s, fcoe_percpu);
 /* Function Prototyes */
 static int fcoe_check_wait_queue(struct fc_lport *);
 static void fcoe_recv_flogi(struct fcoe_softc *, struct fc_frame *, u8 *);
-#ifdef CONFIG_HOTPLUG_CPU
-static int fcoe_cpu_callback(struct notifier_block *, ulong, void *);
-#endif /* CONFIG_HOTPLUG_CPU */
 static int fcoe_device_notification(struct notifier_block *, ulong, void *);
 static void fcoe_dev_setup(void);
 static void fcoe_dev_cleanup(void);
@@ -83,87 +80,6 @@ static struct notifier_block fcoe_notifier = {
         .notifier_call = fcoe_device_notification,
 };
 
-
-#ifdef CONFIG_HOTPLUG_CPU
-static struct notifier_block fcoe_cpu_notifier = {
-        .notifier_call = fcoe_cpu_callback,
-};
-
-/**
- * fcoe_create_percpu_data() - creates the associated cpu data
- * @cpu: index for the cpu where fcoe cpu data will be created
- *
- * create percpu stats block, from cpu add notifier
- *
- * Returns: none
- */
-static void fcoe_create_percpu_data(unsigned int cpu)
-{
-        struct fc_lport *lp;
-        struct fcoe_softc *fc;
-
-        write_lock_bh(&fcoe_hostlist_lock);
-        list_for_each_entry(fc, &fcoe_hostlist, list) {
-                lp = fc->lp;
-                if (lp->dev_stats[cpu] == NULL)
-                        lp->dev_stats[cpu] =
-                                kzalloc(sizeof(struct fcoe_dev_stats),
-                                        GFP_KERNEL);
-        }
-        write_unlock_bh(&fcoe_hostlist_lock);
-}
-
-/**
- * fcoe_destroy_percpu_data() - destroys the associated cpu data
- * @cpu: index for the cpu where fcoe cpu data will destroyed
- *
- * destroy percpu stats block called by cpu add/remove notifier
- *
- * Retuns: none
- */
-static void fcoe_destroy_percpu_data(unsigned int cpu)
-{
-        struct fc_lport *lp;
-        struct fcoe_softc *fc;
-
-        write_lock_bh(&fcoe_hostlist_lock);
-        list_for_each_entry(fc, &fcoe_hostlist, list) {
-                lp = fc->lp;
-                kfree(lp->dev_stats[cpu]);
-                lp->dev_stats[cpu] = NULL;
-        }
-        write_unlock_bh(&fcoe_hostlist_lock);
-}
-
-/**
- * fcoe_cpu_callback() - fcoe cpu hotplug event callback
- * @nfb: callback data block
- * @action: event triggering the callback
- * @hcpu: index for the cpu of this event
- *
- * this creates or destroys per cpu data for fcoe
- *
- * Returns NOTIFY_OK always.
- */
-static int fcoe_cpu_callback(struct notifier_block *nfb, unsigned long action,
-                             void *hcpu)
-{
-        unsigned int cpu = (unsigned long)hcpu;
-
-        switch (action) {
-        case CPU_ONLINE:
-                fcoe_create_percpu_data(cpu);
-                break;
-        case CPU_DEAD:
-                fcoe_destroy_percpu_data(cpu);
-                break;
-        default:
-                break;
-        }
-        return NOTIFY_OK;
-}
-#endif /* CONFIG_HOTPLUG_CPU */
-
 /**
  * fcoe_rcv() - this is the fcoe receive function called by NET_RX_SOFTIRQ
  * @skb: the receive skb
@@ -181,7 +97,6 @@ int fcoe_rcv(struct sk_buff *skb, struct net_device *dev,
         struct fc_lport *lp;
         struct fcoe_rcv_info *fr;
         struct fcoe_softc *fc;
-        struct fcoe_dev_stats *stats;
         struct fc_frame_header *fh;
         struct fcoe_percpu_s *fps;
         unsigned short oxid;
@@ -252,13 +167,7 @@ int fcoe_rcv(struct sk_buff *skb, struct net_device *dev,
 
         return 0;
 err:
-#ifdef CONFIG_SMP
-        stats = lp->dev_stats[smp_processor_id()];
-#else
-        stats = lp->dev_stats[0];
-#endif
-        if (stats)
-                stats->ErrorFrames++;
+        fc_lport_get_stats(lp)->ErrorFrames++;
 
 err2:
         kfree_skb(skb);
@@ -495,11 +404,9 @@ int fcoe_xmit(struct fc_lport *lp, struct fc_frame *fp)
         }
 #endif
         /* update tx stats: regardless if LLD fails */
-        stats = lp->dev_stats[smp_processor_id()];
-        if (stats) {
-                stats->TxFrames++;
-                stats->TxWords += wlen;
-        }
+        stats = fc_lport_get_stats(lp);
+        stats->TxFrames++;
+        stats->TxWords += wlen;
 
         /* send down to lld */
         fr_dev(fp) = lp;
@@ -565,8 +472,6 @@ int fcoe_percpu_receive_thread(void *arg)
                         continue;
                 }
 
-                stats = lp->dev_stats[smp_processor_id()];
-
                 if (unlikely(debug_fcoe)) {
                         FC_DBG("skb_info: len:%d data_len:%d head:%p data:%p "
                                "tail:%p end:%p sum:%d dev:%s",
@@ -593,13 +498,16 @@ int fcoe_percpu_receive_thread(void *arg)
                 hp = (struct fcoe_hdr *) skb_network_header(skb);
                 fh = (struct fc_frame_header *) skb_transport_header(skb);
 
+                stats = fc_lport_get_stats(lp);
                 if (unlikely(FC_FCOE_DECAPS_VER(hp) != FC_FCOE_VER)) {
-                        if (stats) {
-                                if (stats->ErrorFrames < 5)
-                                        FC_DBG("unknown FCoE version %x",
-                                               FC_FCOE_DECAPS_VER(hp));
-                                stats->ErrorFrames++;
-                        }
+                        if (stats->ErrorFrames < 5)
+                                printk(KERN_WARNING "FCoE version "
+                                       "mismatch: The frame has "
+                                       "version %x, but the "
+                                       "initiator supports version "
+                                       "%x\n", FC_FCOE_DECAPS_VER(hp),
+                                       FC_FCOE_VER);
+                        stats->ErrorFrames++;
                         kfree_skb(skb);
                         continue;
                 }
@@ -607,10 +515,8 @@ int fcoe_percpu_receive_thread(void *arg)
                 skb_pull(skb, sizeof(struct fcoe_hdr));
                 fr_len = skb->len - sizeof(struct fcoe_crc_eof);
 
-                if (stats) {
-                        stats->RxFrames++;
-                        stats->RxWords += fr_len / FCOE_WORD_TO_BYTE;
-                }
+                stats->RxFrames++;
+                stats->RxWords += fr_len / FCOE_WORD_TO_BYTE;
 
                 fp = (struct fc_frame *)skb;
                 fc_frame_init(fp);
@@ -885,9 +791,8 @@ static int fcoe_device_notification(struct notifier_block *notifier,
                 if (new_link_up)
                         fc_linkup(lp);
                 else {
-                        stats = lp->dev_stats[smp_processor_id()];
-                        if (stats)
-                                stats->LinkFailureCount++;
+                        stats = fc_lport_get_stats(lp);
+                        stats->LinkFailureCount++;
                         fc_linkdown(lp);
                         fcoe_clean_pending_queue(lp);
                 }
@@ -1371,10 +1276,6 @@ static int __init fcoe_init(void)
         INIT_LIST_HEAD(&fcoe_hostlist);
         rwlock_init(&fcoe_hostlist_lock);
 
-#ifdef CONFIG_HOTPLUG_CPU
-        register_cpu_notifier(&fcoe_cpu_notifier);
-#endif /* CONFIG_HOTPLUG_CPU */
-
         for_each_possible_cpu(cpu) {
                 p = &per_cpu(fcoe_percpu, cpu);
                 skb_queue_head_init(&p->fcoe_rx_list);
@@ -1430,17 +1331,9 @@ static void __exit fcoe_exit(void)
         struct fcoe_percpu_s *p;
         struct sk_buff *skb;
 
-        /*
-         * Stop all call back interfaces
-         */
-#ifdef CONFIG_HOTPLUG_CPU
-        unregister_cpu_notifier(&fcoe_cpu_notifier);
-#endif /* CONFIG_HOTPLUG_CPU */
         fcoe_dev_cleanup();
 
-        /*
-         * stop timer
-         */
+        /* Stop the timer */
         del_timer_sync(&fcoe_timer);
 
         /* releases the associated fcoe transport for each lport */
diff --git a/drivers/scsi/libfc/fc_fcp.c b/drivers/scsi/libfc/fc_fcp.c
index a5725f3b7ce1..0997e8b1dcea 100644
--- a/drivers/scsi/libfc/fc_fcp.c
+++ b/drivers/scsi/libfc/fc_fcp.c
@@ -407,10 +407,12 @@ static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
 
                 if (~crc != le32_to_cpu(fr_crc(fp))) {
 crc_err:
-                        stats = lp->dev_stats[smp_processor_id()];
+                        stats = fc_lport_get_stats(lp);
                         stats->ErrorFrames++;
+                        /* FIXME - per cpu count, not total count! */
                         if (stats->InvalidCRCCount++ < 5)
-                                FC_DBG("CRC error on data frame\n");
+                                printk(KERN_WARNING "CRC error on data frame for port (%6x)\n",
+                                       fc_host_port_id(lp->host));
                         /*
                          * Assume the frame is total garbage.
                          * We may have copied it over the good part
@@ -1752,7 +1754,7 @@ int fc_queuecommand(struct scsi_cmnd *sc_cmd, void (*done)(struct scsi_cmnd *))
         /*
          * setup the data direction
          */
-        stats = lp->dev_stats[smp_processor_id()];
+        stats = fc_lport_get_stats(lp);
         if (sc_cmd->sc_data_direction == DMA_FROM_DEVICE) {
                 fsp->req_flags = FC_SRB_READ;
                 stats->InputRequests++;
diff --git a/drivers/scsi/libfc/fc_lport.c b/drivers/scsi/libfc/fc_lport.c
index 7ef44501ecc6..b8178ef398d7 100644
--- a/drivers/scsi/libfc/fc_lport.c
+++ b/drivers/scsi/libfc/fc_lport.c
@@ -267,10 +267,10 @@ EXPORT_SYMBOL(fc_get_host_speed);
 
 struct fc_host_statistics *fc_get_host_stats(struct Scsi_Host *shost)
 {
-        int i;
         struct fc_host_statistics *fcoe_stats;
         struct fc_lport *lp = shost_priv(shost);
         struct timespec v0, v1;
+        unsigned int cpu;
 
         fcoe_stats = &lp->host_stats;
         memset(fcoe_stats, 0, sizeof(struct fc_host_statistics));
@@ -279,10 +279,11 @@ struct fc_host_statistics *fc_get_host_stats(struct Scsi_Host *shost)
         jiffies_to_timespec(lp->boot_time, &v1);
         fcoe_stats->seconds_since_last_reset = (v0.tv_sec - v1.tv_sec);
 
-        for_each_online_cpu(i) {
-                struct fcoe_dev_stats *stats = lp->dev_stats[i];
-                if (stats == NULL)
-                        continue;
+        for_each_possible_cpu(cpu) {
+                struct fcoe_dev_stats *stats;
+
+                stats = per_cpu_ptr(lp->dev_stats, cpu);
+
                 fcoe_stats->tx_frames += stats->TxFrames;
                 fcoe_stats->tx_words += stats->TxWords;
                 fcoe_stats->rx_frames += stats->RxFrames;