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Message-ID: <1393972341-21135-6-git-send-email-zoltan.kiss@citrix.com>
Date: Tue, 4 Mar 2014 22:32:16 +0000
From: Zoltan Kiss <zoltan.kiss@...rix.com>
To: <ian.campbell@...rix.com>, <wei.liu2@...rix.com>,
<xen-devel@...ts.xenproject.org>
CC: <netdev@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<jonathan.davies@...rix.com>, Zoltan Kiss <zoltan.kiss@...rix.com>
Subject: [PATCH net-next v6 5/10] xen-netback: Remove old TX grant copy definitons and fix indentations
These became obsolete with grant mapping. I've left intentionally the
indentations in this way, to improve readability of previous patches.
NOTE: if bisect brought you here, you should apply the series up until #9,
otherwise Windows guests can't work properly and malicious guests can block
other guests by not releasing their sent packets.
Signed-off-by: Zoltan Kiss <zoltan.kiss@...rix.com>
---
v2:
- move the indentation fixup patch here
v4:
- indentation fixes
drivers/net/xen-netback/common.h | 37 +------------------
drivers/net/xen-netback/netback.c | 72 ++++++++-----------------------------
2 files changed, 15 insertions(+), 94 deletions(-)
diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h
index f35a3ce..2b1cd83 100644
--- a/drivers/net/xen-netback/common.h
+++ b/drivers/net/xen-netback/common.h
@@ -46,39 +46,9 @@
#include <xen/xenbus.h>
typedef unsigned int pending_ring_idx_t;
-#define INVALID_PENDING_RING_IDX (~0U)
-/* For the head field in pending_tx_info: it is used to indicate
- * whether this tx info is the head of one or more coalesced requests.
- *
- * When head != INVALID_PENDING_RING_IDX, it means the start of a new
- * tx requests queue and the end of previous queue.
- *
- * An example sequence of head fields (I = INVALID_PENDING_RING_IDX):
- *
- * ...|0 I I I|5 I|9 I I I|...
- * -->|<-INUSE----------------
- *
- * After consuming the first slot(s) we have:
- *
- * ...|V V V V|5 I|9 I I I|...
- * -----FREE->|<-INUSE--------
- *
- * where V stands for "valid pending ring index". Any number other
- * than INVALID_PENDING_RING_IDX is OK. These entries are considered
- * free and can contain any number other than
- * INVALID_PENDING_RING_IDX. In practice we use 0.
- *
- * The in use non-INVALID_PENDING_RING_IDX (say 0, 5 and 9 in the
- * above example) number is the index into pending_tx_info and
- * mmap_pages arrays.
- */
struct pending_tx_info {
- struct xen_netif_tx_request req; /* coalesced tx request */
- pending_ring_idx_t head; /* head != INVALID_PENDING_RING_IDX
- * if it is head of one or more tx
- * reqs
- */
+ struct xen_netif_tx_request req; /* tx request */
/* callback data for released SKBs. The callback is always
* xenvif_zerocopy_callback, ctx points to the next fragment, desc
* contains the pending_idx
@@ -135,11 +105,6 @@ struct xenvif {
struct pending_tx_info pending_tx_info[MAX_PENDING_REQS];
grant_handle_t grant_tx_handle[MAX_PENDING_REQS];
- /* Coalescing tx requests before copying makes number of grant
- * copy ops greater or equal to number of slots required. In
- * worst case a tx request consumes 2 gnttab_copy.
- */
- struct gnttab_copy tx_copy_ops[2*MAX_PENDING_REQS];
struct gnttab_map_grant_ref tx_map_ops[MAX_PENDING_REQS];
struct gnttab_unmap_grant_ref tx_unmap_ops[MAX_PENDING_REQS];
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 5724468..f74fa92 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -71,16 +71,6 @@ module_param(fatal_skb_slots, uint, 0444);
*/
#define XEN_NETBK_LEGACY_SLOTS_MAX XEN_NETIF_NR_SLOTS_MIN
-/*
- * If head != INVALID_PENDING_RING_IDX, it means this tx request is head of
- * one or more merged tx requests, otherwise it is the continuation of
- * previous tx request.
- */
-static inline int pending_tx_is_head(struct xenvif *vif, RING_IDX idx)
-{
- return vif->pending_tx_info[idx].head != INVALID_PENDING_RING_IDX;
-}
-
static void xenvif_idx_release(struct xenvif *vif, u16 pending_idx,
u8 status);
@@ -762,19 +752,6 @@ static int xenvif_count_requests(struct xenvif *vif,
return slots;
}
-static struct page *xenvif_alloc_page(struct xenvif *vif,
- u16 pending_idx)
-{
- struct page *page;
-
- page = alloc_page(GFP_ATOMIC|__GFP_COLD);
- if (!page)
- return NULL;
- vif->mmap_pages[pending_idx] = page;
-
- return page;
-}
-
static inline void xenvif_tx_create_gop(struct xenvif *vif,
u16 pending_idx,
struct xen_netif_tx_request *txp,
@@ -797,13 +774,9 @@ static struct gnttab_map_grant_ref *xenvif_get_requests(struct xenvif *vif,
struct skb_shared_info *shinfo = skb_shinfo(skb);
skb_frag_t *frags = shinfo->frags;
u16 pending_idx = *((u16 *)skb->cb);
- u16 head_idx = 0;
- int slot, start;
- struct page *page;
- pending_ring_idx_t index, start_idx = 0;
- uint16_t dst_offset;
+ int start;
+ pending_ring_idx_t index;
unsigned int nr_slots;
- struct pending_tx_info *first = NULL;
/* At this point shinfo->nr_frags is in fact the number of
* slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX.
@@ -815,8 +788,8 @@ static struct gnttab_map_grant_ref *xenvif_get_requests(struct xenvif *vif,
for (shinfo->nr_frags = start; shinfo->nr_frags < nr_slots;
shinfo->nr_frags++, txp++, gop++) {
- index = pending_index(vif->pending_cons++);
- pending_idx = vif->pending_ring[index];
+ index = pending_index(vif->pending_cons++);
+ pending_idx = vif->pending_ring[index];
xenvif_tx_create_gop(vif, pending_idx, txp, gop);
frag_set_pending_idx(&frags[shinfo->nr_frags], pending_idx);
}
@@ -824,18 +797,6 @@ static struct gnttab_map_grant_ref *xenvif_get_requests(struct xenvif *vif,
BUG_ON(shinfo->nr_frags > MAX_SKB_FRAGS);
return gop;
-err:
- /* Unwind, freeing all pages and sending error responses. */
- while (shinfo->nr_frags-- > start) {
- xenvif_idx_release(vif,
- frag_get_pending_idx(&frags[shinfo->nr_frags]),
- XEN_NETIF_RSP_ERROR);
- }
- /* The head too, if necessary. */
- if (start)
- xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR);
-
- return NULL;
}
static int xenvif_tx_check_gop(struct xenvif *vif,
@@ -848,7 +809,6 @@ static int xenvif_tx_check_gop(struct xenvif *vif,
struct pending_tx_info *tx_info;
int nr_frags = shinfo->nr_frags;
int i, err, start;
- u16 peek; /* peek into next tx request */
/* Check status of header. */
err = gop->status;
@@ -873,14 +833,12 @@ static int xenvif_tx_check_gop(struct xenvif *vif,
for (i = start; i < nr_frags; i++) {
int j, newerr;
- pending_ring_idx_t head;
pending_idx = frag_get_pending_idx(&shinfo->frags[i]);
tx_info = &vif->pending_tx_info[pending_idx];
- head = tx_info->head;
/* Check error status: if okay then remember grant handle. */
- newerr = (++gop)->status;
+ newerr = (++gop)->status;
if (likely(!newerr)) {
if (vif->grant_tx_handle[pending_idx] !=
@@ -1353,7 +1311,6 @@ static unsigned xenvif_tx_build_gops(struct xenvif *vif, int budget)
(skb_queue_len(&vif->tx_queue) < budget)) {
struct xen_netif_tx_request txreq;
struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX];
- struct page *page;
struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1];
u16 pending_idx;
RING_IDX idx;
@@ -1728,18 +1685,17 @@ static void xenvif_idx_release(struct xenvif *vif, u16 pending_idx,
{
struct pending_tx_info *pending_tx_info;
pending_ring_idx_t index;
- u16 peek; /* peek into next tx request */
unsigned long flags;
- pending_tx_info = &vif->pending_tx_info[pending_idx];
- spin_lock_irqsave(&vif->response_lock, flags);
- make_tx_response(vif, &pending_tx_info->req, status);
- index = pending_index(vif->pending_prod);
- vif->pending_ring[index] = pending_idx;
- /* TX shouldn't use the index before we give it back here */
- mb();
- vif->pending_prod++;
- spin_unlock_irqrestore(&vif->response_lock, flags);
+ pending_tx_info = &vif->pending_tx_info[pending_idx];
+ spin_lock_irqsave(&vif->response_lock, flags);
+ make_tx_response(vif, &pending_tx_info->req, status);
+ index = pending_index(vif->pending_prod);
+ vif->pending_ring[index] = pending_idx;
+ /* TX shouldn't use the index before we give it back here */
+ mb();
+ vif->pending_prod++;
+ spin_unlock_irqrestore(&vif->response_lock, flags);
}
void xenvif_idx_unmap(struct xenvif *vif, u16 pending_idx)
--
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