[Suspend2][ 03/13] [Suspend2] Compression cryptoapi initialisation and cleanup.

[Nigel Cunningham <nigel@suspend2.net>]

Add the routines for preparing cryptoapi for suspend2 use and cleaning it
up.

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

 kernel/power/compression.c |   37 +++++++++++++++++++++++++++++++++++++
 1 files changed, 37 insertions(+), 0 deletions(-)

diff --git a/kernel/power/compression.c b/kernel/power/compression.c
index 3d222b3..470644f 100644
--- a/kernel/power/compression.c
+++ b/kernel/power/compression.c
@@ -92,3 +92,40 @@ static inline void suspend_compress_free
 	page_buffer = NULL;
 }
 
+/* 
+ * suspend_compress_cleanup
+ *
+ * Frees memory allocated for our labours.
+ */
+static void suspend_compress_cleanup(void)
+{
+	if (suspend_compressor_transform) {
+		crypto_free_tfm(suspend_compressor_transform);
+		suspend_compressor_transform = NULL;
+	}
+}
+
+/* 
+ * suspend_crypto_prepare
+ *
+ * Prepare to do some work by allocating buffers and transforms.
+ * Returns: Int: Zero. Even if we can't set up compression, we still
+ * seek to suspend.
+ */
+static int suspend_compress_crypto_prepare(void)
+{
+	if (!*suspend_compressor_name) {
+		printk("Suspend2: Compression enabled but no compressor name set.\n");
+		suspend_compression_ops.disabled = 1;
+		return 0;
+	}
+
+	if (!(suspend_compressor_transform = crypto_alloc_tfm(suspend_compressor_name, 0))) {
+		printk("Suspend2: Failed to initialise the %s compression transform.\n",
+				suspend_compressor_name);
+		return 1;
+	}
+
+	return 0;
+}
+

--
Nigel Cunningham		nigel at suspend2 dot net