From: kaf24@firebug.cl.cam.ac.uk <kaf24@firebug.cl.cam.ac.uk>
Date: Thu, 25 Aug 2005 14:30:06 +0000 (+0000)
Subject: Fix grant-ref allocation in netfront.
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~16844^2~6
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=6e08df4d05043a6c7f95152fe6b1da3d686a12f0;p=xen.git

Fix grant-ref allocation in netfront.

Signed-off-by: Keir Fraser <keir@xensource.com>
---

diff --git a/linux-2.6-xen-sparse/arch/xen/kernel/gnttab.c b/linux-2.6-xen-sparse/arch/xen/kernel/gnttab.c
index e03e78a759..63080358d8 100644
--- a/linux-2.6-xen-sparse/arch/xen/kernel/gnttab.c
+++ b/linux-2.6-xen-sparse/arch/xen/kernel/gnttab.c
@@ -34,9 +34,11 @@
 
 
 EXPORT_SYMBOL(gnttab_grant_foreign_access);
+EXPORT_SYMBOL(gnttab_end_foreign_access_ref);
 EXPORT_SYMBOL(gnttab_end_foreign_access);
 EXPORT_SYMBOL(gnttab_query_foreign_access);
 EXPORT_SYMBOL(gnttab_grant_foreign_transfer);
+EXPORT_SYMBOL(gnttab_end_foreign_transfer_ref);
 EXPORT_SYMBOL(gnttab_end_foreign_transfer);
 EXPORT_SYMBOL(gnttab_alloc_grant_references);
 EXPORT_SYMBOL(gnttab_free_grant_references);
@@ -160,7 +162,7 @@ gnttab_query_foreign_access(grant_ref_t ref)
 }
 
 void
-gnttab_end_foreign_access(grant_ref_t ref, int readonly)
+gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly)
 {
     u16 flags, nflags;
 
@@ -170,7 +172,12 @@ gnttab_end_foreign_access(grant_ref_t ref, int readonly)
             printk(KERN_ALERT "WARNING: g.e. still in use!\n");
     }
     while ( (nflags = synch_cmpxchg(&shared[ref].flags, flags, 0)) != flags );
+}
 
+void
+gnttab_end_foreign_access(grant_ref_t ref, int readonly)
+{
+    gnttab_end_foreign_access_ref(ref, readonly);
     put_free_entry(ref);
 }
 
@@ -201,20 +208,13 @@ gnttab_grant_foreign_transfer_ref(grant_ref_t ref, domid_t domid,
 }
 
 unsigned long
-gnttab_end_foreign_transfer(grant_ref_t ref)
+gnttab_end_foreign_transfer_ref(grant_ref_t ref)
 {
     unsigned long frame = 0;
     u16           flags;
 
     flags = shared[ref].flags;
-#ifdef CONFIG_XEN_NETDEV_GRANT_RX
-    /*
-     * But can't flags == (GTF_accept_transfer | GTF_transfer_completed)
-     * if gnttab_donate executes without interruption???
-     */
-#else
-    ASSERT(flags == (GTF_accept_transfer | GTF_transfer_committed));
-#endif
+
     /*
      * If a transfer is committed then wait for the frame address to appear.
      * Otherwise invalidate the grant entry against future use.
@@ -224,8 +224,14 @@ gnttab_end_foreign_transfer(grant_ref_t ref)
         while ( unlikely((frame = shared[ref].frame) == 0) )
             cpu_relax();
 
-    put_free_entry(ref);
+    return frame;
+}
 
+unsigned long
+gnttab_end_foreign_transfer(grant_ref_t ref)
+{
+    unsigned long frame = gnttab_end_foreign_transfer_ref(ref);
+    put_free_entry(ref);
     return frame;
 }
 
diff --git a/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c b/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
index 79bafd33ea..26238b7fe6 100644
--- a/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
+++ b/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
@@ -363,7 +363,7 @@ static void network_tx_buf_gc(struct net_device *dev)
                        "still in use by backend domain.\n");
                 goto out; 
             }
-            gnttab_end_foreign_access(grant_tx_ref[id], GNTMAP_readonly);
+            gnttab_end_foreign_access_ref(grant_tx_ref[id], GNTMAP_readonly);
             gnttab_release_grant_reference(&gref_tx_head, grant_tx_ref[id]);
             grant_tx_ref[id] = GRANT_INVALID_REF;
 #endif
@@ -649,7 +649,7 @@ static int netif_poll(struct net_device *dev, int *pbudget)
 #ifdef CONFIG_XEN_NETDEV_GRANT_RX
         ref = grant_rx_ref[rx->id];
         grant_rx_ref[rx->id] = GRANT_INVALID_REF;
-        mfn = gnttab_end_foreign_transfer(ref);
+        mfn = gnttab_end_foreign_transfer_ref(ref);
         gnttab_release_grant_reference(&gref_rx_head, ref);
 #endif
 
diff --git a/linux-2.6-xen-sparse/include/asm-xen/gnttab.h b/linux-2.6-xen-sparse/include/asm-xen/gnttab.h
index 5a1f214b16..ab4871e663 100644
--- a/linux-2.6-xen-sparse/include/asm-xen/gnttab.h
+++ b/linux-2.6-xen-sparse/include/asm-xen/gnttab.h
@@ -30,10 +30,12 @@ struct gnttab_free_callback {
 int gnttab_grant_foreign_access(domid_t domid, unsigned long frame,
 				int readonly);
 
+void gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly);
 void gnttab_end_foreign_access(grant_ref_t ref, int readonly);
 
 int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn);
 
+unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref);
 unsigned long gnttab_end_foreign_transfer(grant_ref_t ref);
 
 int gnttab_query_foreign_access(grant_ref_t ref);