cxgb4: Add debugfs facility to inject FL starvation

Add debugfs entry to inject Freelist starvation, used only for debugging
purpose.

Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h b/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h
index 3c109d1..63c30f3 100644 (file)
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h
@@ -650,6 +650,7 @@ struct sge {
        struct sge_rspq **ingr_map; /* qid->queue ingress queue map */
        unsigned long *starving_fl;
        unsigned long *txq_maperr;
+       unsigned long *blocked_fl;
        struct timer_list rx_timer; /* refills starving FLs */
        struct timer_list tx_timer; /* checks Tx queues */
 };

diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c
index 371f75e..3fa3632 100644 (file)
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c
@@ -1959,6 +1959,61 @@ static void add_debugfs_mem(struct adapter *adap, const char *name,
                                 size_mb << 20);
 }
 
+static int blocked_fl_open(struct inode *inode, struct file *file)
+{
+       file->private_data = inode->i_private;
+       return 0;
+}
+
+static ssize_t blocked_fl_read(struct file *filp, char __user *ubuf,
+                              size_t count, loff_t *ppos)
+{
+       int len;
+       const struct adapter *adap = filp->private_data;
+       char *buf;
+       ssize_t size = (adap->sge.egr_sz + 3) / 4 +
+                       adap->sge.egr_sz / 32 + 2; /* includes ,/\n/\0 */
+
+       buf = kzalloc(size, GFP_KERNEL);
+       if (!buf)
+               return -ENOMEM;
+
+       len = snprintf(buf, size - 1, "%*pb\n",
+                      adap->sge.egr_sz, adap->sge.blocked_fl);
+       len += sprintf(buf + len, "\n");
+       size = simple_read_from_buffer(ubuf, count, ppos, buf, len);
+       t4_free_mem(buf);
+       return size;
+}
+
+static ssize_t blocked_fl_write(struct file *filp, const char __user *ubuf,
+                               size_t count, loff_t *ppos)
+{
+       int err;
+       unsigned long *t;
+       struct adapter *adap = filp->private_data;
+
+       t = kcalloc(BITS_TO_LONGS(adap->sge.egr_sz), sizeof(long), GFP_KERNEL);
+       if (!t)
+               return -ENOMEM;
+
+       err = bitmap_parse_user(ubuf, count, t, adap->sge.egr_sz);
+       if (err)
+               return err;
+
+       bitmap_copy(adap->sge.blocked_fl, t, adap->sge.egr_sz);
+       t4_free_mem(t);
+       return count;
+}
+
+static const struct file_operations blocked_fl_fops = {
+       .owner   = THIS_MODULE,
+       .open    = blocked_fl_open,
+       .read    = blocked_fl_read,
+       .write   = blocked_fl_write,
+       .llseek  = generic_file_llseek,
+};
+
 /* Add an array of Debug FS files.
  */
 void add_debugfs_files(struct adapter *adap,
@@ -2022,6 +2077,7 @@ int t4_setup_debugfs(struct adapter *adap)
 #if IS_ENABLED(CONFIG_IPV6)
                { "clip_tbl", &clip_tbl_debugfs_fops, S_IRUSR, 0 },
 #endif
+               { "blocked_fl", &blocked_fl_fops, S_IRUSR | S_IWUSR, 0 },
        };
 
        /* Debug FS nodes common to all T5 and later adapters.

diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
index 73ac153..79ef047 100644 (file)
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
@@ -3844,7 +3844,7 @@ static int adap_init0(struct adapter *adap)
        }
 
        /* Allocate the memory for the vaious egress queue bitmaps
-        * ie starving_fl and txq_maperr.
+        * ie starving_fl, txq_maperr and blocked_fl.
         */
        adap->sge.starving_fl = kcalloc(BITS_TO_LONGS(adap->sge.egr_sz),
                                        sizeof(long), GFP_KERNEL);
@@ -3860,6 +3860,15 @@ static int adap_init0(struct adapter *adap)
                goto bye;
        }
 
+#ifdef CONFIG_DEBUG_FS
+       adap->sge.blocked_fl = kcalloc(BITS_TO_LONGS(adap->sge.egr_sz),
+                                      sizeof(long), GFP_KERNEL);
+       if (!adap->sge.blocked_fl) {
+               ret = -ENOMEM;
+               goto bye;
+       }
+#endif
+
        params[0] = FW_PARAM_PFVF(CLIP_START);
        params[1] = FW_PARAM_PFVF(CLIP_END);
        ret = t4_query_params(adap, adap->mbox, adap->fn, 0, 2, params, val);
@@ -4072,6 +4081,9 @@ bye:
        kfree(adap->sge.ingr_map);
        kfree(adap->sge.starving_fl);
        kfree(adap->sge.txq_maperr);
+#ifdef CONFIG_DEBUG_FS
+       kfree(adap->sge.blocked_fl);
+#endif
        if (ret != -ETIMEDOUT && ret != -EIO)
                t4_fw_bye(adap, adap->mbox);
        return ret;
@@ -4515,6 +4527,9 @@ static void free_some_resources(struct adapter *adapter)
        kfree(adapter->sge.ingr_map);
        kfree(adapter->sge.starving_fl);
        kfree(adapter->sge.txq_maperr);
+#ifdef CONFIG_DEBUG_FS
+       kfree(adapter->sge.blocked_fl);
+#endif
        disable_msi(adapter);
 
        for_each_port(adapter, i)
@@ -4661,6 +4676,9 @@ static int init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 
        setup_memwin(adapter);
        err = adap_init0(adapter);
+#ifdef CONFIG_DEBUG_FS
+       bitmap_zero(adapter->sge.blocked_fl, adapter->sge.egr_sz);
+#endif
        setup_memwin_rdma(adapter);
        if (err)
                goto out_unmap_bar;

diff --git a/drivers/net/ethernet/chelsio/cxgb4/sge.c b/drivers/net/ethernet/chelsio/cxgb4/sge.c
index dd18fcb..19886d5 100644 (file)
--- a/drivers/net/ethernet/chelsio/cxgb4/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/sge.c
@@ -588,6 +588,11 @@ static unsigned int refill_fl(struct adapter *adap, struct sge_fl *q, int n,
        struct rx_sw_desc *sd = &q->sdesc[q->pidx];
        int node;
 
+#ifdef CONFIG_DEBUG_FS
+       if (test_bit(q->cntxt_id - adap->sge.egr_start, adap->sge.blocked_fl))
+               goto out;
+#endif
+
        gfp |= __GFP_NOWARN;
        node = dev_to_node(adap->pdev_dev);