The patch titled
cxgb3: unmap offload packets when they are freed
has been added to the -mm tree. Its filename is
cxgb3-unmap-offload-packets-when-they-are-freed.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: cxgb3: unmap offload packets when they are freed
From: Divy Le Ray <divy@xxxxxxxxxxx>
Offload packets may be DMAed long after their SGE Tx descriptors are done so
they must remain mapped until they are freed rather than until their
descriptors are freed. Unmap such packets through an skb destructor.
Signed-off-by: Divy Le Ray <divy@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/net/cxgb3/sge.c | 63 ++++++++++++++++++++++++++++++++++++--
1 file changed, 61 insertions(+), 2 deletions(-)
diff -puN drivers/net/cxgb3/sge.c~cxgb3-unmap-offload-packets-when-they-are-freed drivers/net/cxgb3/sge.c
--- a/drivers/net/cxgb3/sge.c~cxgb3-unmap-offload-packets-when-they-are-freed
+++ a/drivers/net/cxgb3/sge.c
@@ -105,6 +105,15 @@ struct unmap_info { /* packet unmapping
};
/*
+ * 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
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, str
}
/**
+ * 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
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);
_
Patches currently in -mm which might be from divy@xxxxxxxxxxx are
cxgb3-manage-sysfs-attributes-per-port.patch
cxgb3-private-ioctl-cleanup.patch
cxgb3-fw-version-update.patch
cxgb3-unmap-offload-packets-when-they-are-freed.patch
cxgb3-recovery-from-hw-starvation-of-response-queue.patch
cxgb3-feed-rx-free-list-with-pages.patch
cxgb3-add-sw-lro-support.patch
-
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