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kernel/linux-rt-4.4.41/arch/mips/cavium-octeon/crypto/octeon-crypto.c 1.91 KB
5113f6f70   김현기   kernel add
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  /*
   * 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.
   * Returns with preemption disabled.
   *
   * @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;
  
  	preempt_disable();
  	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);
  	preempt_enable();
  }
  EXPORT_SYMBOL_GPL(octeon_crypto_disable);