s2io: add PCI error recovery support

This patch adds PCI error recovery support to the
s2io 10-Gigabit ethernet device driver. Third revision,
blocks interrupts and the watchdog.

Tested, seems to work well.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Acked-by: Ramkrishna Vepa <Ramkrishna.Vepa@neterion.com>
Cc: Raghavendra Koushik <raghavendra.koushik@neterion.com>
Cc: Wen Xiong <wenxiong@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

2 files changed, 116 insertions, 5 deletions

diff --git a/drivers/net/s2io.c b/drivers/net/s2io.c
index 09078ff84cd2..392ad4a42291 100644
--- a/drivers/net/s2io.c
+++ b/drivers/net/s2io.c
@@ -469,11 +469,18 @@ static struct pci_device_id s2io_tbl[] __devinitdata = {
 
 MODULE_DEVICE_TABLE(pci, s2io_tbl);
 
+static struct pci_error_handlers s2io_err_handler = {
+        .error_detected = s2io_io_error_detected,
+        .slot_reset = s2io_io_slot_reset,
+        .resume = s2io_io_resume,
+};
+
 static struct pci_driver s2io_driver = {
       .name = "S2IO",
       .id_table = s2io_tbl,
       .probe = s2io_init_nic,
       .remove = __devexit_p(s2io_rem_nic),
+      .err_handler = &s2io_err_handler,
 };
 
 /* A simplifier macro used both by init and free shared_mem Fns(). */
@@ -2689,6 +2696,9 @@ static void s2io_netpoll(struct net_device *dev)
         u64 val64 = 0xFFFFFFFFFFFFFFFFULL;
         int i;
 
+        if (pci_channel_offline(nic->pdev))
+                return;
+
         disable_irq(dev->irq);
 
         atomic_inc(&nic->isr_cnt);
@@ -3215,6 +3225,8 @@ static void alarm_intr_handler(struct s2io_nic *nic)
         int i;
         if (atomic_read(&nic->card_state) == CARD_DOWN)
                 return;
+        if (pci_channel_offline(nic->pdev))
+                return;
         nic->mac_control.stats_info->sw_stat.ring_full_cnt = 0;
         /* Handling the XPAK counters update */
         if(nic->mac_control.stats_info->xpak_stat.xpak_timer_count < 72000) {
@@ -4314,6 +4326,10 @@ static irqreturn_t s2io_isr(int irq, void *dev_id)
         struct mac_info *mac_control;
         struct config_param *config;
 
+        /* Pretend we handled any irq's from a disconnected card */
+        if (pci_channel_offline(sp->pdev))
+                return IRQ_NONE;
+
         atomic_inc(&sp->isr_cnt);
         mac_control = &sp->mac_control;
         config = &sp->config;
@@ -6569,7 +6585,7 @@ static void s2io_rem_isr(struct s2io_nic * sp)
         } while(cnt < 5);
 }
 
-static void s2io_card_down(struct s2io_nic * sp)
+static void do_s2io_card_down(struct s2io_nic * sp, int do_io)
 {
         int cnt = 0;
         struct XENA_dev_config __iomem *bar0 = sp->bar0;
@@ -6584,7 +6600,8 @@ static void s2io_card_down(struct s2io_nic * sp)
         atomic_set(&sp->card_state, CARD_DOWN);
 
         /* disable Tx and Rx traffic on the NIC */
-        stop_nic(sp);
+        if (do_io)
+                stop_nic(sp);
 
         s2io_rem_isr(sp);
 
@@ -6592,7 +6609,7 @@ static void s2io_card_down(struct s2io_nic * sp)
         tasklet_kill(&sp->task);
 
         /* Check if the device is Quiescent and then Reset the NIC */
-        do {
+        while(do_io) {
                 /* As per the HW requirement we need to replenish the
                  * receive buffer to avoid the ring bump. Since there is
                  * no intention of processing the Rx frame at this pointwe are
@@ -6617,8 +6634,9 @@ static void s2io_card_down(struct s2io_nic * sp)
                                   (unsigned long long) val64);
                         break;
                 }
-        } while (1);
-        s2io_reset(sp);
+        }
+        if (do_io)
+                s2io_reset(sp);
 
         spin_lock_irqsave(&sp->tx_lock, flags);
         /* Free all Tx buffers */
@@ -6633,6 +6651,11 @@ static void s2io_card_down(struct s2io_nic * sp)
         clear_bit(0, &(sp->link_state));
 }
 
+static void s2io_card_down(struct s2io_nic * sp)
+{
+        do_s2io_card_down(sp, 1);
+}
+
 static int s2io_card_up(struct s2io_nic * sp)
 {
         int i, ret = 0;
@@ -8010,3 +8033,86 @@ static void lro_append_pkt(struct s2io_nic *sp, struct lro *lro,
         sp->mac_control.stats_info->sw_stat.clubbed_frms_cnt++;
         return;
 }
+
+/**
+ * s2io_io_error_detected - called when PCI error is detected
+ * @pdev: Pointer to PCI device
+ * @state: The current pci conneection state
+ *
+ * This function is called after a PCI bus error affecting
+ * this device has been detected.
+ */
+static pci_ers_result_t s2io_io_error_detected(struct pci_dev *pdev,
+                                               pci_channel_state_t state)
+{
+        struct net_device *netdev = pci_get_drvdata(pdev);
+        struct s2io_nic *sp = netdev->priv;
+
+        netif_device_detach(netdev);
+
+        if (netif_running(netdev)) {
+                /* Bring down the card, while avoiding PCI I/O */
+                do_s2io_card_down(sp, 0);
+                sp->device_close_flag = TRUE;   /* Device is shut down. */
+        }
+        pci_disable_device(pdev);
+
+        return PCI_ERS_RESULT_NEED_RESET;
+}
+
+/**
+ * s2io_io_slot_reset - called after the pci bus has been reset.
+ * @pdev: Pointer to PCI device
+ *
+ * Restart the card from scratch, as if from a cold-boot.
+ * At this point, the card has exprienced a hard reset,
+ * followed by fixups by BIOS, and has its config space
+ * set up identically to what it was at cold boot.
+ */
+static pci_ers_result_t s2io_io_slot_reset(struct pci_dev *pdev)
+{
+        struct net_device *netdev = pci_get_drvdata(pdev);
+        struct s2io_nic *sp = netdev->priv;
+
+        if (pci_enable_device(pdev)) {
+                printk(KERN_ERR "s2io: "
+                       "Cannot re-enable PCI device after reset.\n");
+                return PCI_ERS_RESULT_DISCONNECT;
+        }
+
+        pci_set_master(pdev);
+        s2io_reset(sp);
+
+        return PCI_ERS_RESULT_RECOVERED;
+}
+
+/**
+ * s2io_io_resume - called when traffic can start flowing again.
+ * @pdev: Pointer to PCI device
+ *
+ * This callback is called when the error recovery driver tells
+ * us that its OK to resume normal operation.
+ */
+static void s2io_io_resume(struct pci_dev *pdev)
+{
+        struct net_device *netdev = pci_get_drvdata(pdev);
+        struct s2io_nic *sp = netdev->priv;
+
+        if (netif_running(netdev)) {
+                if (s2io_card_up(sp)) {
+                        printk(KERN_ERR "s2io: "
+                               "Can't bring device back up after reset.\n");
+                        return;
+                }
+
+                if (s2io_set_mac_addr(netdev, netdev->dev_addr) == FAILURE) {
+                        s2io_card_down(sp);
+                        printk(KERN_ERR "s2io: "
+                               "Can't resetore mac addr after reset.\n");
+                        return;
+                }
+        }
+
+        netif_device_attach(netdev);
+        netif_wake_queue(netdev);
+}
diff --git a/drivers/net/s2io.h b/drivers/net/s2io.h
index 54baa0b8ec7c..b9b660702abd 100644
--- a/drivers/net/s2io.h
+++ b/drivers/net/s2io.h
@@ -1052,6 +1052,11 @@ static void lro_append_pkt(struct s2io_nic *sp, struct lro *lro,
                            struct sk_buff *skb, u32 tcp_len);
 static int rts_ds_steer(struct s2io_nic *nic, u8 ds_codepoint, u8 ring);
 
+static pci_ers_result_t s2io_io_error_detected(struct pci_dev *pdev,
+                                              pci_channel_state_t state);
+static pci_ers_result_t s2io_io_slot_reset(struct pci_dev *pdev);
+static void s2io_io_resume(struct pci_dev *pdev);
+
 #define s2io_tcp_mss(skb) skb_shinfo(skb)->gso_size
 #define s2io_udp_mss(skb) skb_shinfo(skb)->gso_size
 #define s2io_offload_type(skb) skb_shinfo(skb)->gso_type