projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| d7f864be CM |
1 | /* |
| 2 | * arch/arm/kernel/thumbee.c | |
| 3 | * | |
| 4 | * Copyright (C) 2008 ARM Limited | |
| 5 | * | |
| 6 | * This program is free software; you can redistribute it and/or modify | |
| 7 | * it under the terms of the GNU General Public License version 2 as | |
| 8 | * published by the Free Software Foundation. | |
| 9 | * | |
| 10 | * This program is distributed in the hope that it will be useful, | |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 13 | * GNU General Public License for more details. | |
| 14 | * | |
| 15 | * You should have received a copy of the GNU General Public License | |
| 16 | * along with this program; if not, write to the Free Software | |
| 17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 18 | */ | |
| 19 | ||
| 20 | #include <linux/kernel.h> | |
| 21 | #include <linux/init.h> | |
| 22 | ||
| 23 | #include <asm/thread_notify.h> | |
| 24 | ||
| 25 | /* | |
| 26 | * Access to the ThumbEE Handler Base register | |
| 27 | */ | |
| 7f1fd31d | 28 | static inline unsigned long teehbr_read(void) |
| d7f864be CM |
29 | { |
| 30 | unsigned long v; | |
| 31 | asm("mrc p14, 6, %0, c1, c0, 0\n" : "=r" (v)); | |
| 32 | return v; | |
| 33 | } | |
| 34 | ||
| 35 | static inline void teehbr_write(unsigned long v) | |
| 36 | { | |
| 37 | asm("mcr p14, 6, %0, c1, c0, 0\n" : : "r" (v)); | |
| 38 | } | |
| 39 | ||
| 40 | static int thumbee_notifier(struct notifier_block *self, unsigned long cmd, void *t) | |
| 41 | { | |
| 42 | struct thread_info *thread = t; | |
| 43 | ||
| 44 | switch (cmd) { | |
| 45 | case THREAD_NOTIFY_FLUSH: | |
| 46 | thread->thumbee_state = 0; | |
| 47 | break; | |
| 48 | case THREAD_NOTIFY_SWITCH: | |
| 49 | current_thread_info()->thumbee_state = teehbr_read(); | |
| 50 | teehbr_write(thread->thumbee_state); | |
| 51 | break; | |
| 52 | } | |
| 53 | ||
| 54 | return NOTIFY_DONE; | |
| 55 | } | |
| 56 | ||
| 57 | static struct notifier_block thumbee_notifier_block = { | |
| 58 | .notifier_call = thumbee_notifier, | |
| 59 | }; | |
| 60 | ||
| 61 | static int __init thumbee_init(void) | |
| 62 | { | |
| 63 | unsigned long pfr0; | |
| 64 | unsigned int cpu_arch = cpu_architecture(); | |
| 65 | ||
| 66 | if (cpu_arch < CPU_ARCH_ARMv7) | |
| 67 | return 0; | |
| 68 | ||
| 69 | /* processor feature register 0 */ | |
| 70 | asm("mrc p15, 0, %0, c0, c1, 0\n" : "=r" (pfr0)); | |
| 71 | if ((pfr0 & 0x0000f000) != 0x00001000) | |
| 72 | return 0; | |
| 73 | ||
| 74 | printk(KERN_INFO "ThumbEE CPU extension supported.\n"); | |
| 75 | elf_hwcap |= HWCAP_THUMBEE; | |
| 76 | thread_register_notifier(&thumbee_notifier_block); | |
| 77 | ||
| 78 | return 0; | |
| 79 | } | |
| 80 | ||
| 81 | late_initcall(thumbee_init); |