jme: Fix unmap error (Causing system freeze)

[ upstream commit 94c5b41b327e08de0ddf563237855f55080652a1 ]

This patch add the missing dma_unmap().
Which solved the critical issue of system freeze on heavy load.

Michal Miroslaw's rejected patch:
[PATCH v2 10/46] net: jme: convert to generic DMA API
Pointed out the issue also, thank you Michal.
But the fix was incorrect. It would unmap needed address
when low memory.

Got lots of feedback from End user and Gentoo Bugzilla.
https://bugs.gentoo.org/show_bug.cgi?id=373109
Thank you all. :)

Cc: stable@kernel.org
Signed-off-by: Guo-Fu Tseng <cooldavid@cooldavid.org>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

diff --git a/drivers/net/jme.c b/drivers/net/jme.c
index f0643ac4aff19838156edd27ea5ad8732e8c985a..0d0aafd2444d3b3afbbd849f2375557cdabda621 100644 (file)
--- a/drivers/net/jme.c
+++ b/drivers/net/jme.c
@@ -678,20 +678,28 @@ jme_make_new_rx_buf(struct jme_adapter *jme, int i)
        struct jme_ring *rxring = &(jme->rxring[0]);
        struct jme_buffer_info *rxbi = rxring->bufinf + i;
        struct sk_buff *skb;
+       dma_addr_t mapping;
 
        skb = netdev_alloc_skb(jme->dev,
                jme->dev->mtu + RX_EXTRA_LEN);
        if (unlikely(!skb))
                return -ENOMEM;
 
+       mapping = pci_map_page(jme->pdev, virt_to_page(skb->data),
+                              offset_in_page(skb->data), skb_tailroom(skb),
+                              PCI_DMA_FROMDEVICE);
+       if (unlikely(pci_dma_mapping_error(jme->pdev, mapping))) {
+               dev_kfree_skb(skb);
+               return -ENOMEM;
+       }
+
+       if (likely(rxbi->mapping))
+               pci_unmap_page(jme->pdev, rxbi->mapping,
+                              rxbi->len, PCI_DMA_FROMDEVICE);
+
        rxbi->skb = skb;
        rxbi->len = skb_tailroom(skb);
-       rxbi->mapping = pci_map_page(jme->pdev,
-                                       virt_to_page(skb->data),
-                                       offset_in_page(skb->data),
-                                       rxbi->len,
-                                       PCI_DMA_FROMDEVICE);
-
+       rxbi->mapping = mapping;
        return 0;
 }