[CRYPTO] padlock: Helper module padlock.ko

Compile a helper module padlock.ko that will try
to autoload all configured padlock algorithms.

This also provides backward compatibility with 
the ancient times before padlock.ko was renamed 
to padlock-aes.ko
Signed-off-by: Michal Ludvig <michal@logix.cz>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/Kconfig

 menu "Hardware crypto devices"
 
 config CRYPTO_DEV_PADLOCK
-	bool "Support for VIA PadLock ACE"
+	tristate "Support for VIA PadLock ACE"
 	depends on X86_32
 	select CRYPTO_ALGAPI
-	default y
+	default m
 	help
 	  Some VIA processors come with an integrated crypto engine
 	  (so called VIA PadLock ACE, Advanced Cryptography Engine)
@@ -12,8 +12,17 @@ config CRYPTO_DEV_PADLOCK
 	  operations with supported algorithms.
 	  
 	  The instructions are used only when the CPU supports them.
-	  Otherwise software encryption is used. If you are unsure,
-	  say Y.
+	  Otherwise software encryption is used.
+
+	  Selecting M for this option will compile a helper module
+	  padlock.ko that should autoload all below configured
+	  algorithms. Don't worry if your hardware does not support
+	  some or all of them. In such case padlock.ko will
+	  simply write a single line into the kernel log informing
+	  about its failure but everything will keep working fine.
+
+	  If you are unsure, say M. The compiled module will be
+	  called padlock.ko
 
 config CRYPTO_DEV_PADLOCK_AES
 	tristate "PadLock driver for AES algorithm"

drivers/crypto/Makefile

+obj-$(CONFIG_CRYPTO_DEV_PADLOCK) += padlock.o
 obj-$(CONFIG_CRYPTO_DEV_PADLOCK_AES) += padlock-aes.o
 obj-$(CONFIG_CRYPTO_DEV_PADLOCK_SHA) += padlock-sha.o

drivers/crypto/padlock-aes.c

@@ -544,6 +544,3 @@ MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Michal Ludvig");
 
 MODULE_ALIAS("aes-padlock");
-
-/* This module used to be called padlock. */
-MODULE_ALIAS("padlock");

drivers/crypto/padlock.c

+/*
+ * Cryptographic API.
+ *
+ * Support for VIA PadLock hardware crypto engine.
+ *
+ * Copyright (c) 2006  Michal Ludvig <michal@logix.cz>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/crypto.h>
+#include <linux/cryptohash.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/scatterlist.h>
+#include "padlock.h"
+
+static int __init padlock_init(void)
+{
+	int success = 0;
+
+	if (crypto_alg_available("aes-padlock", 0))
+		success++;
+
+	if (crypto_alg_available("sha1-padlock", 0))
+		success++;
+
+	if (crypto_alg_available("sha256-padlock", 0))
+		success++;
+
+	if (!success) {
+		printk(KERN_WARNING PFX "No VIA PadLock drivers have been loaded.\n");
+		return -ENODEV;
+	}
+
+	printk(KERN_NOTICE PFX "%d drivers are available.\n", success);
+
+	return 0;
+}
+
+static void __exit padlock_fini(void)
+{
+}
+
+module_init(padlock_init);
+module_exit(padlock_fini);
+
+MODULE_DESCRIPTION("Load all configured PadLock algorithms.");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Michal Ludvig");
+