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/export.h> 11 #include <linux/interrupt.h> 12 #include <linux/sched/task_stack.h> 13 14 #include "octeon-crypto.h" 15 16 /** 17 * Enable access to Octeon's COP2 crypto hardware for kernel use. Wrap any 18 * crypto operations in calls to octeon_crypto_enable/disable in order to make 19 * sure the state of COP2 isn't corrupted if userspace is also performing 20 * hardware crypto operations. Allocate the state parameter on the stack. 21 * Returns with preemption disabled. 22 * 23 * @state: Pointer to state structure to store current COP2 state in. 24 * 25 * Returns: Flags to be passed to octeon_crypto_disable() 26 */ octeon_crypto_enable(struct octeon_cop2_state * state)27unsigned long octeon_crypto_enable(struct octeon_cop2_state *state) 28 { 29 int status; 30 unsigned long flags; 31 32 preempt_disable(); 33 local_irq_save(flags); 34 status = read_c0_status(); 35 write_c0_status(status | ST0_CU2); 36 if (KSTK_STATUS(current) & ST0_CU2) { 37 octeon_cop2_save(&(current->thread.cp2)); 38 KSTK_STATUS(current) &= ~ST0_CU2; 39 status &= ~ST0_CU2; 40 } else if (status & ST0_CU2) { 41 octeon_cop2_save(state); 42 } 43 local_irq_restore(flags); 44 return status & ST0_CU2; 45 } 46 EXPORT_SYMBOL_GPL(octeon_crypto_enable); 47 48 /** 49 * Disable access to Octeon's COP2 crypto hardware in the kernel. This must be 50 * called after an octeon_crypto_enable() before any context switch or return to 51 * userspace. 52 * 53 * @state: Pointer to COP2 state to restore 54 * @flags: Return value from octeon_crypto_enable() 55 */ octeon_crypto_disable(struct octeon_cop2_state * state,unsigned long crypto_flags)56void octeon_crypto_disable(struct octeon_cop2_state *state, 57 unsigned long crypto_flags) 58 { 59 unsigned long flags; 60 61 local_irq_save(flags); 62 if (crypto_flags & ST0_CU2) 63 octeon_cop2_restore(state); 64 else 65 write_c0_status(read_c0_status() & ~ST0_CU2); 66 local_irq_restore(flags); 67 preempt_enable(); 68 } 69 EXPORT_SYMBOL_GPL(octeon_crypto_disable); 70