[Xen-changelog] Update gnttab_free_callback_list locking.

[Xen patchbot -unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User cl349@xxxxxxxxxxxxxxxxxxxx
# Node ID 96f1f6c710891448318a6287a10e004297fb8563
# Parent  af9e3ae3a9b1e342514305399fe5dcdfa5639385
Update gnttab_free_callback_list locking.
Signed-off-by: Christian Limpach <Christian.Limpach@xxxxxxxxxxxx>

diff -r af9e3ae3a9b1 -r 96f1f6c71089 
linux-2.6-xen-sparse/arch/xen/kernel/gnttab.c
--- a/linux-2.6-xen-sparse/arch/xen/kernel/gnttab.c     Tue Aug 23 08:45:13 2005
+++ b/linux-2.6-xen-sparse/arch/xen/kernel/gnttab.c     Tue Aug 23 09:24:46 2005
@@ -68,13 +68,11 @@
     return fh;
 }
 
-static void do_free_callbacks(void)
-{
-    struct gnttab_free_callback *callback, *next;
-    spin_lock_irq(&gnttab_free_callback_list_lock);
-    callback = gnttab_free_callback_list;
+static void do_free_callbacks(unsigned long flags)
+{
+    struct gnttab_free_callback *callback = gnttab_free_callback_list, *next;
     gnttab_free_callback_list = NULL;
-    spin_unlock_irq(&gnttab_free_callback_list_lock);
+    spin_unlock_irqrestore(&gnttab_free_callback_list_lock, flags);
     while (callback) {
        next = callback->next;
        callback->next = NULL;
@@ -88,12 +86,14 @@
     grant_ref_t ref)
 {
     grant_ref_t fh, nfh = gnttab_free_head;
+    unsigned long flags;
     do { gnttab_free_list[ref] = fh = nfh; wmb(); }
     while ( unlikely((nfh = cmpxchg(&gnttab_free_head, fh, ref)) != fh) );
-    spin_lock_irq(&gnttab_free_callback_list_lock);
+    spin_lock_irqsave(&gnttab_free_callback_list_lock, flags);
     if ( unlikely(gnttab_free_callback_list) )
-       do_free_callbacks();
-    spin_unlock_irq(&gnttab_free_callback_list_lock);
+       do_free_callbacks(flags);
+    else
+       spin_unlock_irqrestore(&gnttab_free_callback_list_lock, flags);
 }
 
 /*
@@ -276,14 +276,15 @@
 gnttab_request_free_callback(struct gnttab_free_callback *callback,
                             void (*fn)(void *), void *arg)
 {
+    unsigned long flags;
     if (callback->next)
        return;
     callback->fn = fn;
     callback->arg = arg;
-    spin_lock_irq(&gnttab_free_callback_list_lock);
+    spin_lock_irqsave(&gnttab_free_callback_list_lock, flags);
     callback->next = gnttab_free_callback_list;
     gnttab_free_callback_list = callback;
-    spin_unlock_irq(&gnttab_free_callback_list_lock);
+    spin_unlock_irqrestore(&gnttab_free_callback_list_lock, flags);
 }
 
 /*

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