[Suspend2][ 04/13] [Suspend2] Compression initialise & cleanup routines.

[Nigel Cunningham <nigel@suspend2.net>]

These routines handle the initialisation and cleanup for compression,
invoking the buffer allocation and cryptoapi setup routines.

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

 kernel/power/compression.c |   59 ++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 59 insertions(+), 0 deletions(-)

diff --git a/kernel/power/compression.c b/kernel/power/compression.c
index 470644f..44d46be 100644
--- a/kernel/power/compression.c
+++ b/kernel/power/compression.c
@@ -129,3 +129,62 @@ static int suspend_compress_crypto_prepa
 	return 0;
 }
 
+/* 
+ * suspend_compress_write_cleanup(): Write unflushed data and free workspace.
+ * 
+ * Returns: Result of writing last page.
+ */
+static int suspend_compress_rw_cleanup(int rw)
+{
+	int ret = 0;
+	
+	if (rw == WRITE && suspend_compressor_transform)
+		ret = next_driver->write_chunk(virt_to_page(local_buffer));
+
+	suspend_compress_cleanup();
+	suspend_compress_free_local_buffer();
+
+	return ret;
+}
+
+/* 
+ * suspend_compress_rw_init()
+ * @stream_number:	Ignored.
+ *
+ * Allocate buffers and prepare to compress data.
+ * Returns: Zero on success, -ENOMEM if unable to vmalloc.
+ */
+static int suspend_compress_rw_init(int rw, int stream_number)
+{
+	int result;
+	
+	next_driver = suspend_get_next_filter(&suspend_compression_ops);
+
+	if (!next_driver) {
+		printk("Compression Driver: Argh! Nothing follows me in"
+				" the pipeline!");
+		return -ECHILD;
+	}
+
+	if ((result = suspend_compress_crypto_prepare() ||
+	     suspend_compression_ops.disabled))
+		return result;
+	
+	if ((result = suspend_compress_allocate_local_buffer()))
+		return result;
+
+	if (rw == READ)
+		bufofs = PAGE_SIZE;
+	else {
+		/* Only reset the stats if starting to write an image */
+		if (stream_number == 2)
+			bytes_in = bytes_out = 0;
+	
+		bufofs = 0;
+	}
+
+	position = 0;
+
+	return 0;
+}
+

--
Nigel Cunningham		nigel at suspend2 dot net