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authorDavid Woodhouse <dwmw2@infradead.org>2006-10-01 17:55:53 +0100
committerDavid Woodhouse <dwmw2@infradead.org>2006-10-01 17:55:53 +0100
commit8a84fc15ae5cafcc366dd85cf8e1ab2040679abc (patch)
tree5d8dce194c9667fa92e9ec9f545cec867a9a1e0d /kernel/kfifo.c
parent28b79ff9661b22e4c41c0d00d4ab8503e810f13d (diff)
parent82965addad66fce61a92c5f03104ea90b0b87124 (diff)
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Manually resolve conflict in include/mtd/Kbuild Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Diffstat (limited to 'kernel/kfifo.c')
-rw-r--r--kernel/kfifo.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/kernel/kfifo.c b/kernel/kfifo.c
index 64ab045c3d9..5d1d907378a 100644
--- a/kernel/kfifo.c
+++ b/kernel/kfifo.c
@@ -122,6 +122,13 @@ unsigned int __kfifo_put(struct kfifo *fifo,
len = min(len, fifo->size - fifo->in + fifo->out);
+ /*
+ * Ensure that we sample the fifo->out index -before- we
+ * start putting bytes into the kfifo.
+ */
+
+ smp_mb();
+
/* first put the data starting from fifo->in to buffer end */
l = min(len, fifo->size - (fifo->in & (fifo->size - 1)));
memcpy(fifo->buffer + (fifo->in & (fifo->size - 1)), buffer, l);
@@ -129,6 +136,13 @@ unsigned int __kfifo_put(struct kfifo *fifo,
/* then put the rest (if any) at the beginning of the buffer */
memcpy(fifo->buffer, buffer + l, len - l);
+ /*
+ * Ensure that we add the bytes to the kfifo -before-
+ * we update the fifo->in index.
+ */
+
+ smp_wmb();
+
fifo->in += len;
return len;
@@ -154,6 +168,13 @@ unsigned int __kfifo_get(struct kfifo *fifo,
len = min(len, fifo->in - fifo->out);
+ /*
+ * Ensure that we sample the fifo->in index -before- we
+ * start removing bytes from the kfifo.
+ */
+
+ smp_rmb();
+
/* first get the data from fifo->out until the end of the buffer */
l = min(len, fifo->size - (fifo->out & (fifo->size - 1)));
memcpy(buffer, fifo->buffer + (fifo->out & (fifo->size - 1)), l);
@@ -161,6 +182,13 @@ unsigned int __kfifo_get(struct kfifo *fifo,
/* then get the rest (if any) from the beginning of the buffer */
memcpy(buffer + l, fifo->buffer, len - l);
+ /*
+ * Ensure that we remove the bytes from the kfifo -before-
+ * we update the fifo->out index.
+ */
+
+ smp_mb();
+
fifo->out += len;
return len;