skge: add a debug interface

Add a debugfs interface to look at internal ring state.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

3 files changed, 156 insertions, 0 deletions

diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 8f99a0626616..83d52c8acab0 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -2173,6 +2173,16 @@ config SKGE
           To compile this driver as a module, choose M here: the module
           will be called skge.  This is recommended.
 
+config SKGE_DEBUG
+       bool "Debugging interface"
+       depends on SKGE && DEBUG_FS
+       help
+         This option adds the ability to dump driver state for debugging.
+         The file debugfs/skge/ethX displays the state of the internal
+         transmit and receive rings.
+
+         If unsure, say N.
+
 config SKY2
         tristate "SysKonnect Yukon2 support"
         depends on PCI
diff --git a/drivers/net/skge.c b/drivers/net/skge.c
index 953f8023f24c..cf7d79bc5e74 100644
--- a/drivers/net/skge.c
+++ b/drivers/net/skge.c
@@ -36,6 +36,8 @@
 #include <linux/delay.h>
 #include <linux/crc32.h>
 #include <linux/dma-mapping.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
 #include <linux/mii.h>
 #include <asm/irq.h>
 
@@ -3676,6 +3678,145 @@ static int skge_reset(struct skge_hw *hw)
         return 0;
 }
 
+
+#ifdef CONFIG_SKGE_DEBUG
+
+static struct dentry *skge_debug;
+
+static int skge_debug_show(struct seq_file *seq, void *v)
+{
+        struct net_device *dev = seq->private;
+        const struct skge_port *skge = netdev_priv(dev);
+        const struct skge_hw *hw = skge->hw;
+        const struct skge_element *e;
+
+        if (!netif_running(dev))
+                return -ENETDOWN;
+
+        seq_printf(seq, "IRQ src=%x mask=%x\n", skge_read32(hw, B0_ISRC),
+                   skge_read32(hw, B0_IMSK));
+
+        seq_printf(seq, "Tx Ring: (%d)\n", skge_avail(&skge->tx_ring));
+        for (e = skge->tx_ring.to_clean; e != skge->tx_ring.to_use; e = e->next) {
+                const struct skge_tx_desc *t = e->desc;
+                seq_printf(seq, "%#x dma=%#x%08x %#x csum=%#x/%x/%x\n",
+                           t->control, t->dma_hi, t->dma_lo, t->status,
+                           t->csum_offs, t->csum_write, t->csum_start);
+        }
+
+        seq_printf(seq, "\nRx Ring: \n");
+        for (e = skge->rx_ring.to_clean; ; e = e->next) {
+                const struct skge_rx_desc *r = e->desc;
+
+                if (r->control & BMU_OWN)
+                        break;
+
+                seq_printf(seq, "%#x dma=%#x%08x %#x %#x csum=%#x/%x\n",
+                           r->control, r->dma_hi, r->dma_lo, r->status,
+                           r->timestamp, r->csum1, r->csum1_start);
+        }
+
+        return 0;
+}
+
+static int skge_debug_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, skge_debug_show, inode->i_private);
+}
+
+static const struct file_operations skge_debug_fops = {
+        .owner          = THIS_MODULE,
+        .open           = skge_debug_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
+
+/*
+ * Use network device events to create/remove/rename
+ * debugfs file entries
+ */
+static int skge_device_event(struct notifier_block *unused,
+                             unsigned long event, void *ptr)
+{
+        struct net_device *dev = ptr;
+        struct skge_port *skge;
+        struct dentry *d;
+
+        if (dev->open != &skge_up || !skge_debug)
+                goto done;
+
+        skge = netdev_priv(dev);
+        switch(event) {
+        case NETDEV_CHANGENAME:
+                if (skge->debugfs) {
+                        d = debugfs_rename(skge_debug, skge->debugfs,
+                                           skge_debug, dev->name);
+                        if (d)
+                                skge->debugfs = d;
+                        else {
+                                pr_info(PFX "%s: rename failed\n", dev->name);
+                                debugfs_remove(skge->debugfs);
+                        }
+                }
+                break;
+
+        case NETDEV_GOING_DOWN:
+                if (skge->debugfs) {
+                        debugfs_remove(skge->debugfs);
+                        skge->debugfs = NULL;
+                }
+                break;
+
+        case NETDEV_UP:
+                d = debugfs_create_file(dev->name, S_IRUGO,
+                                        skge_debug, dev,
+                                        &skge_debug_fops);
+                if (!d || IS_ERR(d))
+                        pr_info(PFX "%s: debugfs create failed\n",
+                               dev->name);
+                else
+                        skge->debugfs = d;
+                break;
+        }
+
+done:
+        return NOTIFY_DONE;
+}
+
+static struct notifier_block skge_notifier = {
+        .notifier_call = skge_device_event,
+};
+
+
+static __init void skge_debug_init(void)
+{
+        struct dentry *ent;
+
+        ent = debugfs_create_dir("skge", NULL);
+        if (!ent || IS_ERR(ent)) {
+                pr_info(PFX "debugfs create directory failed\n");
+                return;
+        }
+
+        skge_debug = ent;
+        register_netdevice_notifier(&skge_notifier);
+}
+
+static __exit void skge_debug_cleanup(void)
+{
+        if (skge_debug) {
+                unregister_netdevice_notifier(&skge_notifier);
+                debugfs_remove(skge_debug);
+                skge_debug = NULL;
+        }
+}
+
+#else
+#define skge_debug_init()
+#define skge_debug_cleanup()
+#endif
+
 /* Initialize network device */
 static struct net_device *skge_devinit(struct skge_hw *hw, int port,
                                        int highmem)
@@ -4040,12 +4181,14 @@ static struct pci_driver skge_driver = {
 
 static int __init skge_init_module(void)
 {
+        skge_debug_init();
         return pci_register_driver(&skge_driver);
 }
 
 static void __exit skge_cleanup_module(void)
 {
         pci_unregister_driver(&skge_driver);
+        skge_debug_cleanup();
 }
 
 module_init(skge_init_module);
diff --git a/drivers/net/skge.h b/drivers/net/skge.h
index 51754246d59d..17caccbb7685 100644
--- a/drivers/net/skge.h
+++ b/drivers/net/skge.h
@@ -2469,6 +2469,9 @@ struct skge_port {
         void                 *mem;      /* PCI memory for rings */
         dma_addr_t           dma;
         unsigned long        mem_size;
+#ifdef CONFIG_SKGE_DEBUG
+        struct dentry        *debugfs;
+#endif
 };