x86, efi: Set runtime_version to the EFI spec revision
[linux/fpc-iii.git] / arch / arm / mach-ep93xx / crunch.c
bloba4a2ab9648c92cd5d7a10a1eb646e63c65d2a366
1 /*
2 * arch/arm/kernel/crunch.c
3 * Cirrus MaverickCrunch context switching and handling
5 * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/module.h>
13 #include <linux/types.h>
14 #include <linux/kernel.h>
15 #include <linux/signal.h>
16 #include <linux/sched.h>
17 #include <linux/init.h>
18 #include <linux/io.h>
20 #include <asm/thread_notify.h>
22 #include "soc.h"
24 struct crunch_state *crunch_owner;
26 void crunch_task_release(struct thread_info *thread)
28 local_irq_disable();
29 if (crunch_owner == &thread->crunchstate)
30 crunch_owner = NULL;
31 local_irq_enable();
34 static int crunch_enabled(u32 devcfg)
36 return !!(devcfg & EP93XX_SYSCON_DEVCFG_CPENA);
39 static int crunch_do(struct notifier_block *self, unsigned long cmd, void *t)
41 struct thread_info *thread = (struct thread_info *)t;
42 struct crunch_state *crunch_state;
43 u32 devcfg;
45 crunch_state = &thread->crunchstate;
47 switch (cmd) {
48 case THREAD_NOTIFY_FLUSH:
49 memset(crunch_state, 0, sizeof(*crunch_state));
52 * FALLTHROUGH: Ensure we don't try to overwrite our newly
53 * initialised state information on the first fault.
56 case THREAD_NOTIFY_EXIT:
57 crunch_task_release(thread);
58 break;
60 case THREAD_NOTIFY_SWITCH:
61 devcfg = __raw_readl(EP93XX_SYSCON_DEVCFG);
62 if (crunch_enabled(devcfg) || crunch_owner == crunch_state) {
64 * We don't use ep93xx_syscon_swlocked_write() here
65 * because we are on the context switch path and
66 * preemption is already disabled.
68 devcfg ^= EP93XX_SYSCON_DEVCFG_CPENA;
69 __raw_writel(0xaa, EP93XX_SYSCON_SWLOCK);
70 __raw_writel(devcfg, EP93XX_SYSCON_DEVCFG);
72 break;
75 return NOTIFY_DONE;
78 static struct notifier_block crunch_notifier_block = {
79 .notifier_call = crunch_do,
82 int __init crunch_init(void)
84 thread_register_notifier(&crunch_notifier_block);
85 elf_hwcap |= HWCAP_CRUNCH;
87 return 0;