projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| c17fad11 LB |
1 | /* |
| 2 | * arch/arm/kernel/crunch.c | |
| 3 | * Cirrus MaverickCrunch context switching and handling | |
| 4 | * | |
| 5 | * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org> | |
| 6 | * | |
| 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. | |
| 10 | */ | |
| 11 | ||
| 12 | #include <linux/module.h> | |
| 13 | #include <linux/config.h> | |
| 14 | #include <linux/types.h> | |
| 15 | #include <linux/kernel.h> | |
| 16 | #include <linux/signal.h> | |
| 17 | #include <linux/sched.h> | |
| 18 | #include <linux/init.h> | |
| 19 | #include <asm/arch/ep93xx-regs.h> | |
| 20 | #include <asm/thread_notify.h> | |
| 21 | #include <asm/io.h> | |
| 22 | ||
| 23 | struct crunch_state *crunch_owner; | |
| 24 | ||
| 25 | void crunch_task_release(struct thread_info *thread) | |
| 26 | { | |
| 27 | local_irq_disable(); | |
| 28 | if (crunch_owner == &thread->crunchstate) | |
| 29 | crunch_owner = NULL; | |
| 30 | local_irq_enable(); | |
| 31 | } | |
| 32 | ||
| 33 | static int crunch_enabled(u32 devcfg) | |
| 34 | { | |
| 35 | return !!(devcfg & EP93XX_SYSCON_DEVICE_CONFIG_CRUNCH_ENABLE); | |
| 36 | } | |
| 37 | ||
| 38 | static int crunch_do(struct notifier_block *self, unsigned long cmd, void *t) | |
| 39 | { | |
| 40 | struct thread_info *thread = (struct thread_info *)t; | |
| 41 | struct crunch_state *crunch_state; | |
| 42 | u32 devcfg; | |
| 43 | ||
| 44 | crunch_state = &thread->crunchstate; | |
| 45 | ||
| 46 | switch (cmd) { | |
| 47 | case THREAD_NOTIFY_FLUSH: | |
| 48 | memset(crunch_state, 0, sizeof(*crunch_state)); | |
| 49 | ||
| 50 | /* | |
| 51 | * FALLTHROUGH: Ensure we don't try to overwrite our newly | |
| 52 | * initialised state information on the first fault. | |
| 53 | */ | |
| 54 | ||
| 55 | case THREAD_NOTIFY_RELEASE: | |
| 56 | crunch_task_release(thread); | |
| 57 | break; | |
| 58 | ||
| 59 | case THREAD_NOTIFY_SWITCH: | |
| 60 | devcfg = __raw_readl(EP93XX_SYSCON_DEVICE_CONFIG); | |
| 61 | if (crunch_enabled(devcfg) || crunch_owner == crunch_state) { | |
| 62 | devcfg ^= EP93XX_SYSCON_DEVICE_CONFIG_CRUNCH_ENABLE; | |
| 63 | __raw_writel(0xaa, EP93XX_SYSCON_SWLOCK); | |
| 64 | __raw_writel(devcfg, EP93XX_SYSCON_DEVICE_CONFIG); | |
| 65 | } | |
| 66 | break; | |
| 67 | } | |
| 68 | ||
| 69 | return NOTIFY_DONE; | |
| 70 | } | |
| 71 | ||
| 72 | static struct notifier_block crunch_notifier_block = { | |
| 73 | .notifier_call = crunch_do, | |
| 74 | }; | |
| 75 | ||
| 76 | static int __init crunch_init(void) | |
| 77 | { | |
| 78 | thread_register_notifier(&crunch_notifier_block); | |
| 79 | ||
| 80 | return 0; | |
| 81 | } | |
| 82 | ||
| 83 | late_initcall(crunch_init); |