[PATCH net-next v3 3/3] xen-netback: Functional follow-up patch for grant mapping series

From: Zoltan Kiss
Date: Mon Mar 24 2014 - 20:00:53 EST


Ian made some late comments about the grant mapping series, I incorporated the
functional outcomes into this patch:

- use callback_param macro to shorten access to pending_tx_info in
xenvif_fill_frags() and xenvif_tx_submit()
- print an error message in xenvif_idx_unmap() before panic

Signed-off-by: Zoltan Kiss <zoltan.kiss@xxxxxxxxxx>
---
v2:
- expand commit message and split this into 2 patch
- fix typos

v3: change the subject

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index f5c440b..0efa32d 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -99,6 +99,9 @@ static inline unsigned long idx_to_kaddr(struct xenvif *vif,
return (unsigned long)pfn_to_kaddr(idx_to_pfn(vif, idx));
}

+#define callback_param(vif, pending_idx) \
+ (vif->pending_tx_info[pending_idx].callback_struct)
+
/* Find the containing VIF's structure from a pointer in pending_tx_info array
*/
static inline struct xenvif* ubuf_to_vif(struct ubuf_info *ubuf)
@@ -1020,12 +1023,12 @@ static void xenvif_fill_frags(struct xenvif *vif, struct sk_buff *skb)
/* If this is not the first frag, chain it to the previous*/
if (unlikely(prev_pending_idx == INVALID_PENDING_IDX))
skb_shinfo(skb)->destructor_arg =
- &vif->pending_tx_info[pending_idx].callback_struct;
+ &callback_param(vif, pending_idx);
else if (likely(pending_idx != prev_pending_idx))
- vif->pending_tx_info[prev_pending_idx].callback_struct.ctx =
- &(vif->pending_tx_info[pending_idx].callback_struct);
+ callback_param(vif, prev_pending_idx).ctx =
+ &callback_param(vif, pending_idx);

- vif->pending_tx_info[pending_idx].callback_struct.ctx = NULL;
+ callback_param(vif, pending_idx).ctx = NULL;
prev_pending_idx = pending_idx;

txp = &vif->pending_tx_info[pending_idx].req;
@@ -1395,13 +1398,13 @@ static int xenvif_tx_submit(struct xenvif *vif)
memcpy(skb->data,
(void *)(idx_to_kaddr(vif, pending_idx)|txp->offset),
data_len);
- vif->pending_tx_info[pending_idx].callback_struct.ctx = NULL;
+ callback_param(vif, pending_idx).ctx = NULL;
if (data_len < txp->size) {
/* Append the packet payload as a fragment. */
txp->offset += data_len;
txp->size -= data_len;
skb_shinfo(skb)->destructor_arg =
- &vif->pending_tx_info[pending_idx].callback_struct;
+ &callback_param(vif, pending_idx);
} else {
/* Schedule a response immediately. */
xenvif_idx_unmap(vif, pending_idx);
@@ -1678,11 +1680,20 @@ void xenvif_idx_unmap(struct xenvif *vif, u16 pending_idx)
idx_to_kaddr(vif, pending_idx),
GNTMAP_host_map,
vif->grant_tx_handle[pending_idx]);
xenvif_grant_handle_reset(vif, pending_idx);

ret = gnttab_unmap_refs(&tx_unmap_op, NULL,
&vif->mmap_pages[pending_idx], 1);
- BUG_ON(ret);
+ if (ret) {
+ netdev_err(vif->dev,
+ "Unmap fail: ret: %d pending_idx: %d host_addr: %llx handle: %x status: %d\n",
+ ret,
+ pending_idx,
+ tx_unmap_op.host_addr,
+ tx_unmap_op.handle,
+ tx_unmap_op.status);
+ BUG();
+ }

xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_OKAY);
}

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