1 files changed, 61 insertions, 2 deletions

diff --git a/drivers/net/cxgb3/sge.c b/drivers/net/cxgb3/sge.c
index 3f2cf8a07c61..822a598c0db1 100644
--- a/drivers/net/cxgb3/sge.c
+++ b/drivers/net/cxgb3/sge.c
@@ -105,6 +105,15 @@ struct unmap_info {		/* packet unmapping info, overlays skb->cb */
 };
 
 /*
+ * Holds unmapping information for Tx packets that need deferred unmapping.
+ * This structure lives at skb->head and must be allocated by callers.
+ */
+struct deferred_unmap_info {
+        struct pci_dev *pdev;
+        dma_addr_t addr[MAX_SKB_FRAGS + 1];
+};
+
+/*
  * Maps a number of flits to the number of Tx descriptors that can hold them.
  * The formula is
  *
@@ -252,10 +261,13 @@ static void free_tx_desc(struct adapter *adapter, struct sge_txq *q,
         struct pci_dev *pdev = adapter->pdev;
         unsigned int cidx = q->cidx;
 
+        const int need_unmap = need_skb_unmap() &&
+                               q->cntxt_id >= FW_TUNNEL_SGEEC_START;
+
         d = &q->sdesc[cidx];
         while (n--) {
                 if (d->skb) {   /* an SGL is present */
-                        if (need_skb_unmap())
+                        if (need_unmap)
                                 unmap_skb(d->skb, q, cidx, pdev);
                         if (d->skb->priority == cidx)
                                 kfree_skb(d->skb);
@@ -1227,6 +1239,50 @@ int t3_mgmt_tx(struct adapter *adap, struct sk_buff *skb)
 }
 
 /**
+ *      deferred_unmap_destructor - unmap a packet when it is freed
+ *      @skb: the packet
+ *
+ *      This is the packet destructor used for Tx packets that need to remain
+ *      mapped until they are freed rather than until their Tx descriptors are
+ *      freed.
+ */
+static void deferred_unmap_destructor(struct sk_buff *skb)
+{
+        int i;
+        const dma_addr_t *p;
+        const struct skb_shared_info *si;
+        const struct deferred_unmap_info *dui;
+        const struct unmap_info *ui = (struct unmap_info *)skb->cb;
+
+        dui = (struct deferred_unmap_info *)skb->head;
+        p = dui->addr;
+
+        if (ui->len)
+                pci_unmap_single(dui->pdev, *p++, ui->len, PCI_DMA_TODEVICE);
+
+        si = skb_shinfo(skb);
+        for (i = 0; i < si->nr_frags; i++)
+                pci_unmap_page(dui->pdev, *p++, si->frags[i].size,
+                               PCI_DMA_TODEVICE);
+}
+
+static void setup_deferred_unmapping(struct sk_buff *skb, struct pci_dev *pdev,
+                                     const struct sg_ent *sgl, int sgl_flits)
+{
+        dma_addr_t *p;
+        struct deferred_unmap_info *dui;
+
+        dui = (struct deferred_unmap_info *)skb->head;
+        dui->pdev = pdev;
+        for (p = dui->addr; sgl_flits >= 3; sgl++, sgl_flits -= 3) {
+                *p++ = be64_to_cpu(sgl->addr[0]);
+                *p++ = be64_to_cpu(sgl->addr[1]);
+        }
+        if (sgl_flits)
+                *p = be64_to_cpu(sgl->addr[0]);
+}
+
+/**
  *      write_ofld_wr - write an offload work request
  *      @adap: the adapter
  *      @skb: the packet to send
@@ -1262,8 +1318,11 @@ static void write_ofld_wr(struct adapter *adap, struct sk_buff *skb,
         sgp = ndesc == 1 ? (struct sg_ent *)&d->flit[flits] : sgl;
         sgl_flits = make_sgl(skb, sgp, skb->h.raw, skb->tail - skb->h.raw,
                              adap->pdev);
-        if (need_skb_unmap())
+        if (need_skb_unmap()) {
+                setup_deferred_unmapping(skb, adap->pdev, sgp, sgl_flits);
+                skb->destructor = deferred_unmap_destructor;
                 ((struct unmap_info *)skb->cb)->len = skb->tail - skb->h.raw;
+        }
 
         write_wr_hdr_sgl(ndesc, skb, d, pidx, q, sgl, flits, sgl_flits,
                          gen, from->wr_hi, from->wr_lo);