1 /* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Copyright (C) 2004-2012 Cavium Networks 7 */ 8 9 #include <asm/cop2.h> 10 #include <linux/module.h> 11 #include <linux/interrupt.h> 12 13 #include "octeon-crypto.h" 14 15 /** 16 * Enable access to Octeon's COP2 crypto hardware for kernel use. Wrap any 17 * crypto operations in calls to octeon_crypto_enable/disable in order to make 18 * sure the state of COP2 isn't corrupted if userspace is also performing 19 * hardware crypto operations. Allocate the state parameter on the stack. 20 * Returns with preemption disabled. 21 * 22 * @state: Pointer to state structure to store current COP2 state in. 23 * 24 * Returns: Flags to be passed to octeon_crypto_disable() 25 */ 26 unsigned long octeon_crypto_enable(struct octeon_cop2_state *state) 27 { 28 int status; 29 unsigned long flags; 30 31 preempt_disable(); 32 local_irq_save(flags); 33 status = read_c0_status(); 34 write_c0_status(status | ST0_CU2); 35 if (KSTK_STATUS(current) & ST0_CU2) { 36 octeon_cop2_save(&(current->thread.cp2)); 37 KSTK_STATUS(current) &= ~ST0_CU2; 38 status &= ~ST0_CU2; 39 } else if (status & ST0_CU2) { 40 octeon_cop2_save(state); 41 } 42 local_irq_restore(flags); 43 return status & ST0_CU2; 44 } 45 EXPORT_SYMBOL_GPL(octeon_crypto_enable); 46 47 /** 48 * Disable access to Octeon's COP2 crypto hardware in the kernel. This must be 49 * called after an octeon_crypto_enable() before any context switch or return to 50 * userspace. 51 * 52 * @state: Pointer to COP2 state to restore 53 * @flags: Return value from octeon_crypto_enable() 54 */ 55 void octeon_crypto_disable(struct octeon_cop2_state *state, 56 unsigned long crypto_flags) 57 { 58 unsigned long flags; 59 60 local_irq_save(flags); 61 if (crypto_flags & ST0_CU2) 62 octeon_cop2_restore(state); 63 else 64 write_c0_status(read_c0_status() & ~ST0_CU2); 65 local_irq_restore(flags); 66 preempt_enable(); 67 } 68 EXPORT_SYMBOL_GPL(octeon_crypto_disable); 69