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/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index c28b90d..caaad7b 100644
--- 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 @@
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 @@
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 @@
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;
