Aaro Koskinen | f421258 | 2014-12-21 22:53:58 +0200 | [diff] [blame] | 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. |
Aaro Koskinen | c3bc38d | 2015-03-08 22:07:42 +0200 | [diff] [blame] | 20 | * Returns with preemption disabled. |
Aaro Koskinen | f421258 | 2014-12-21 22:53:58 +0200 | [diff] [blame] | 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 | |
Aaro Koskinen | c3bc38d | 2015-03-08 22:07:42 +0200 | [diff] [blame] | 31 | preempt_disable(); |
Aaro Koskinen | f421258 | 2014-12-21 22:53:58 +0200 | [diff] [blame] | 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); |
Aaro Koskinen | c3bc38d | 2015-03-08 22:07:42 +0200 | [diff] [blame] | 66 | preempt_enable(); |
Aaro Koskinen | f421258 | 2014-12-21 22:53:58 +0200 | [diff] [blame] | 67 | } |
| 68 | EXPORT_SYMBOL_GPL(octeon_crypto_disable); |