linux/arch/mips/cavium-octeon/crypto/octeon-crypto.c

67 lines
1.9 KiB
C

/*
* 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);