MIPS: OCTEON: add crypto helper functions

Add crypto helper functions which are needed for kernel level usage.
The code for these has been extracted from the EdgeRouter Pro GPL tarball.

While at it, also delete duplicate definitions of the functions.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

3 files changed, 88 insertions, 0 deletions

diff --git a/arch/mips/cavium-octeon/crypto/Makefile b/arch/mips/cavium-octeon/crypto/Makefile
new file mode 100644
index 000000000000..739b80366c25
--- /dev/null
+++ b/arch/mips/cavium-octeon/crypto/Makefile
@@ -0,0 +1,5 @@
+#
+# OCTEON-specific crypto modules.
+#
+
+obj-y += octeon-crypto.o
diff --git a/arch/mips/cavium-octeon/crypto/octeon-crypto.c b/arch/mips/cavium-octeon/crypto/octeon-crypto.c
new file mode 100644
index 000000000000..7c82ff463b65
--- /dev/null
+++ b/arch/mips/cavium-octeon/crypto/octeon-crypto.c
@@ -0,0 +1,66 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2004-2012 Cavium Networks
+ */
+
+#include <asm/cop2.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+
+#include "octeon-crypto.h"
+
+/**
+ * Enable access to Octeon's COP2 crypto hardware for kernel use. Wrap any
+ * crypto operations in calls to octeon_crypto_enable/disable in order to make
+ * sure the state of COP2 isn't corrupted if userspace is also performing
+ * hardware crypto operations. Allocate the state parameter on the stack.
+ * Preemption must be disabled to prevent context switches.
+ *
+ * @state: Pointer to state structure to store current COP2 state in.
+ *
+ * Returns: Flags to be passed to octeon_crypto_disable()
+ */
+unsigned long octeon_crypto_enable(struct octeon_cop2_state *state)
+{
+	int status;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	status = read_c0_status();
+	write_c0_status(status | ST0_CU2);
+	if (KSTK_STATUS(current) & ST0_CU2) {
+		octeon_cop2_save(&(current->thread.cp2));
+		KSTK_STATUS(current) &= ~ST0_CU2;
+		status &= ~ST0_CU2;
+	} else if (status & ST0_CU2) {
+		octeon_cop2_save(state);
+	}
+	local_irq_restore(flags);
+	return status & ST0_CU2;
+}
+EXPORT_SYMBOL_GPL(octeon_crypto_enable);
+
+/**
+ * Disable access to Octeon's COP2 crypto hardware in the kernel. This must be
+ * called after an octeon_crypto_enable() before any context switch or return to
+ * userspace.
+ *
+ * @state:	Pointer to COP2 state to restore
+ * @flags:	Return value from octeon_crypto_enable()
+ */
+void octeon_crypto_disable(struct octeon_cop2_state *state,
+			   unsigned long crypto_flags)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	if (crypto_flags & ST0_CU2)
+		octeon_cop2_restore(state);
+	else
+		write_c0_status(read_c0_status() & ~ST0_CU2);
+	local_irq_restore(flags);
+}
+EXPORT_SYMBOL_GPL(octeon_crypto_disable);
diff --git a/arch/mips/cavium-octeon/crypto/octeon-crypto.h b/arch/mips/cavium-octeon/crypto/octeon-crypto.h
new file mode 100644
index 000000000000..5ca86d4ead52
--- /dev/null
+++ b/arch/mips/cavium-octeon/crypto/octeon-crypto.h
@@ -0,0 +1,17 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2012-2013 Cavium Inc., All Rights Reserved.
+ */
+#ifndef __LINUX_OCTEON_CRYPTO_H
+#define __LINUX_OCTEON_CRYPTO_H
+
+#include <linux/sched.h>
+
+extern unsigned long octeon_crypto_enable(struct octeon_cop2_state *state);
+extern void octeon_crypto_disable(struct octeon_cop2_state *state,
+				  unsigned long flags);
+
+#endif /* __LINUX_OCTEON_CRYPTO_H */