stmmac: export DMA TX/RX rings via debugfs (v3)

This patch adds the following debugFs entry to dump the
RX/TX DMA rings:

/sys/kernel/debug/stmmaceth/descriptors_status

This is an example:

=======================
  RX descriptor ring
=======================
[0] DES0=0x85ee0320 DES1=0x1fff1fff BUF1=0x5fae2022 BUF2=0x0
[1] DES0=0x85ee0320 DES1=0x1fff1fff BUF1=0x5fae0022 BUF2=0x0
[2] DES0=0x81460320 DES1=0x1fff1fff BUF1=0x5f9dd022 BUF2=0x0

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index cda61e37c357b817ccf17399b0475caf03ad6a98..ae7f56312f080a87d65e2d216cac5b3afe26c997 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
@@ -11,6 +11,13 @@ config STMMAC_ETH
 
 if STMMAC_ETH
 
+config STMMAC_DEBUG_FS
+       bool "Enable monitoring via sysFS "
+       default n
+       depends on STMMAC_ETH && DEBUG_FS
+       -- help
+         The stmmac entry in /sys reports DMA TX/RX rings.
+
 config STMMAC_DA
        bool "STMMAC DMA arbitration scheme"
        default n

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index c28b90d350076b9373c03c97c52761fe4072eb35..caaad7b14621610a6aa86543698ee2eed31b2c70 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -48,6 +48,10 @@
 #include <linux/slab.h>
 #include <linux/prefetch.h>
 #include "stmmac.h"
+#ifdef CONFIG_STMMAC_DEBUG_FS
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#endif
 
 #define STMMAC_RESOURCE_NAME   "stmmaceth"
 
@@ -1425,6 +1429,96 @@ static int stmmac_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
        return ret;
 }
 
+#ifdef CONFIG_STMMAC_DEBUG_FS
+static struct dentry *stmmac_fs_dir;
+static struct dentry *stmmac_rings_status;
+
+static int stmmac_sysfs_ring_read(struct seq_file *seq, void *v)
+{
+       struct tmp_s {
+               u64 a;
+               unsigned int b;
+               unsigned int c;
+       };
+       int i;
+       struct net_device *dev = seq->private;
+       struct stmmac_priv *priv = netdev_priv(dev);
+
+       seq_printf(seq, "=======================\n");
+       seq_printf(seq, " RX descriptor ring\n");
+       seq_printf(seq, "=======================\n");
+
+       for (i = 0; i < priv->dma_rx_size; i++) {
+               struct tmp_s *x = (struct tmp_s *)(priv->dma_rx + i);
+               seq_printf(seq, "[%d] DES0=0x%x DES1=0x%x BUF1=0x%x BUF2=0x%x",
+                          i, (unsigned int)(x->a),
+                          (unsigned int)((x->a) >> 32), x->b, x->c);
+               seq_printf(seq, "\n");
+       }
+
+       seq_printf(seq, "\n");
+       seq_printf(seq, "=======================\n");
+       seq_printf(seq, "  TX descriptor ring\n");
+       seq_printf(seq, "=======================\n");
+
+       for (i = 0; i < priv->dma_tx_size; i++) {
+               struct tmp_s *x = (struct tmp_s *)(priv->dma_tx + i);
+               seq_printf(seq, "[%d] DES0=0x%x DES1=0x%x BUF1=0x%x BUF2=0x%x",
+                          i, (unsigned int)(x->a),
+                          (unsigned int)((x->a) >> 32), x->b, x->c);
+               seq_printf(seq, "\n");
+       }
+
+       return 0;
+}
+
+static int stmmac_sysfs_ring_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, stmmac_sysfs_ring_read, inode->i_private);
+}
+
+static const struct file_operations stmmac_rings_status_fops = {
+       .owner = THIS_MODULE,
+       .open = stmmac_sysfs_ring_open,
+       .read = seq_read,
+       .llseek = seq_lseek,
+       .release = seq_release,
+};
+
+static int stmmac_init_fs(struct net_device *dev)
+{
+       /* Create debugfs entries */
+       stmmac_fs_dir = debugfs_create_dir(STMMAC_RESOURCE_NAME, NULL);
+
+       if (!stmmac_fs_dir || IS_ERR(stmmac_fs_dir)) {
+               pr_err("ERROR %s, debugfs create directory failed\n",
+                      STMMAC_RESOURCE_NAME);
+
+               return -ENOMEM;
+       }
+
+       /* Entry to report DMA RX/TX rings */
+       stmmac_rings_status = debugfs_create_file("descriptors_status",
+                                          S_IRUGO, stmmac_fs_dir, dev,
+                                          &stmmac_rings_status_fops);
+
+       if (!stmmac_rings_status || IS_ERR(stmmac_rings_status)) {
+               pr_info("ERROR creating stmmac ring debugfs file\n");
+               debugfs_remove(stmmac_fs_dir);
+
+               return -ENOMEM;
+       }
+
+       return 0;
+}
+
+static void stmmac_exit_fs(void)
+{
+       debugfs_remove(stmmac_rings_status);
+       debugfs_remove(stmmac_fs_dir);
+}
+#endif /* CONFIG_STMMAC_DEBUG_FS */
+
 static const struct net_device_ops stmmac_netdev_ops = {
        .ndo_open = stmmac_open,
        .ndo_start_xmit = stmmac_xmit,
@@ -1651,6 +1745,13 @@ static int stmmac_dvr_probe(struct platform_device *pdev)
        if (ret < 0)
                goto out_unregister;
        pr_debug("registered!\n");
+
+#ifdef CONFIG_STMMAC_DEBUG_FS
+       ret = stmmac_init_fs(ndev);
+       if (ret < 0)
+               pr_warning("\tFailed debugFS registration");
+#endif
+
        return 0;
 
 out_unregister:
@@ -1703,6 +1804,10 @@ static int stmmac_dvr_remove(struct platform_device *pdev)
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        release_mem_region(res->start, resource_size(res));
 
+#ifdef CONFIG_STMMAC_DEBUG_FS
+       stmmac_exit_fs();
+#endif
+
        free_netdev(ndev);
 
        return 0;