| 1 | /* |
| 2 | * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu> |
| 3 | * Copyright (C) 2008-2009 PetaLogix |
| 4 | * Copyright (C) 2006 Atmark Techno, Inc. |
| 5 | * |
| 6 | * This file is subject to the terms and conditions of the GNU General Public |
| 7 | * License. See the file "COPYING" in the main directory of this archive |
| 8 | * for more details. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/sched.h> |
| 13 | #include <linux/pm.h> |
| 14 | #include <linux/tick.h> |
| 15 | #include <linux/bitops.h> |
| 16 | #include <asm/system.h> |
| 17 | #include <asm/pgalloc.h> |
| 18 | #include <asm/uaccess.h> /* for USER_DS macros */ |
| 19 | #include <asm/cacheflush.h> |
| 20 | |
| 21 | void show_regs(struct pt_regs *regs) |
| 22 | { |
| 23 | printk(KERN_INFO " Registers dump: mode=%X\r\n", regs->pt_mode); |
| 24 | printk(KERN_INFO " r1=%08lX, r2=%08lX, r3=%08lX, r4=%08lX\n", |
| 25 | regs->r1, regs->r2, regs->r3, regs->r4); |
| 26 | printk(KERN_INFO " r5=%08lX, r6=%08lX, r7=%08lX, r8=%08lX\n", |
| 27 | regs->r5, regs->r6, regs->r7, regs->r8); |
| 28 | printk(KERN_INFO " r9=%08lX, r10=%08lX, r11=%08lX, r12=%08lX\n", |
| 29 | regs->r9, regs->r10, regs->r11, regs->r12); |
| 30 | printk(KERN_INFO " r13=%08lX, r14=%08lX, r15=%08lX, r16=%08lX\n", |
| 31 | regs->r13, regs->r14, regs->r15, regs->r16); |
| 32 | printk(KERN_INFO " r17=%08lX, r18=%08lX, r19=%08lX, r20=%08lX\n", |
| 33 | regs->r17, regs->r18, regs->r19, regs->r20); |
| 34 | printk(KERN_INFO " r21=%08lX, r22=%08lX, r23=%08lX, r24=%08lX\n", |
| 35 | regs->r21, regs->r22, regs->r23, regs->r24); |
| 36 | printk(KERN_INFO " r25=%08lX, r26=%08lX, r27=%08lX, r28=%08lX\n", |
| 37 | regs->r25, regs->r26, regs->r27, regs->r28); |
| 38 | printk(KERN_INFO " r29=%08lX, r30=%08lX, r31=%08lX, rPC=%08lX\n", |
| 39 | regs->r29, regs->r30, regs->r31, regs->pc); |
| 40 | printk(KERN_INFO " msr=%08lX, ear=%08lX, esr=%08lX, fsr=%08lX\n", |
| 41 | regs->msr, regs->ear, regs->esr, regs->fsr); |
| 42 | } |
| 43 | |
| 44 | void (*pm_idle)(void); |
| 45 | void (*pm_power_off)(void) = NULL; |
| 46 | EXPORT_SYMBOL(pm_power_off); |
| 47 | |
| 48 | static int hlt_counter = 1; |
| 49 | |
| 50 | void disable_hlt(void) |
| 51 | { |
| 52 | hlt_counter++; |
| 53 | } |
| 54 | EXPORT_SYMBOL(disable_hlt); |
| 55 | |
| 56 | void enable_hlt(void) |
| 57 | { |
| 58 | hlt_counter--; |
| 59 | } |
| 60 | EXPORT_SYMBOL(enable_hlt); |
| 61 | |
| 62 | static int __init nohlt_setup(char *__unused) |
| 63 | { |
| 64 | hlt_counter = 1; |
| 65 | return 1; |
| 66 | } |
| 67 | __setup("nohlt", nohlt_setup); |
| 68 | |
| 69 | static int __init hlt_setup(char *__unused) |
| 70 | { |
| 71 | hlt_counter = 0; |
| 72 | return 1; |
| 73 | } |
| 74 | __setup("hlt", hlt_setup); |
| 75 | |
| 76 | void default_idle(void) |
| 77 | { |
| 78 | if (likely(hlt_counter)) { |
| 79 | local_irq_disable(); |
| 80 | stop_critical_timings(); |
| 81 | cpu_relax(); |
| 82 | start_critical_timings(); |
| 83 | local_irq_enable(); |
| 84 | } else { |
| 85 | clear_thread_flag(TIF_POLLING_NRFLAG); |
| 86 | smp_mb__after_clear_bit(); |
| 87 | local_irq_disable(); |
| 88 | while (!need_resched()) |
| 89 | cpu_sleep(); |
| 90 | local_irq_enable(); |
| 91 | set_thread_flag(TIF_POLLING_NRFLAG); |
| 92 | } |
| 93 | } |
| 94 | |
| 95 | void cpu_idle(void) |
| 96 | { |
| 97 | set_thread_flag(TIF_POLLING_NRFLAG); |
| 98 | |
| 99 | /* endless idle loop with no priority at all */ |
| 100 | while (1) { |
| 101 | void (*idle)(void) = pm_idle; |
| 102 | |
| 103 | if (!idle) |
| 104 | idle = default_idle; |
| 105 | |
| 106 | tick_nohz_idle_enter(); |
| 107 | rcu_idle_enter(); |
| 108 | while (!need_resched()) |
| 109 | idle(); |
| 110 | rcu_idle_exit(); |
| 111 | tick_nohz_idle_exit(); |
| 112 | |
| 113 | schedule_preempt_disabled(); |
| 114 | check_pgt_cache(); |
| 115 | } |
| 116 | } |
| 117 | |
| 118 | void flush_thread(void) |
| 119 | { |
| 120 | } |
| 121 | |
| 122 | int copy_thread(unsigned long clone_flags, unsigned long usp, |
| 123 | unsigned long unused, |
| 124 | struct task_struct *p, struct pt_regs *regs) |
| 125 | { |
| 126 | struct pt_regs *childregs = task_pt_regs(p); |
| 127 | struct thread_info *ti = task_thread_info(p); |
| 128 | |
| 129 | *childregs = *regs; |
| 130 | if (user_mode(regs)) |
| 131 | childregs->r1 = usp; |
| 132 | else |
| 133 | childregs->r1 = ((unsigned long) ti) + THREAD_SIZE; |
| 134 | |
| 135 | #ifndef CONFIG_MMU |
| 136 | memset(&ti->cpu_context, 0, sizeof(struct cpu_context)); |
| 137 | ti->cpu_context.r1 = (unsigned long)childregs; |
| 138 | ti->cpu_context.msr = (unsigned long)childregs->msr; |
| 139 | #else |
| 140 | |
| 141 | /* if creating a kernel thread then update the current reg (we don't |
| 142 | * want to use the parent's value when restoring by POP_STATE) */ |
| 143 | if (kernel_mode(regs)) |
| 144 | /* save new current on stack to use POP_STATE */ |
| 145 | childregs->CURRENT_TASK = (unsigned long)p; |
| 146 | /* if returning to user then use the parent's value of this register */ |
| 147 | |
| 148 | /* if we're creating a new kernel thread then just zeroing all |
| 149 | * the registers. That's OK for a brand new thread.*/ |
| 150 | /* Pls. note that some of them will be restored in POP_STATE */ |
| 151 | if (kernel_mode(regs)) |
| 152 | memset(&ti->cpu_context, 0, sizeof(struct cpu_context)); |
| 153 | /* if this thread is created for fork/vfork/clone, then we want to |
| 154 | * restore all the parent's context */ |
| 155 | /* in addition to the registers which will be restored by POP_STATE */ |
| 156 | else { |
| 157 | ti->cpu_context = *(struct cpu_context *)regs; |
| 158 | childregs->msr |= MSR_UMS; |
| 159 | } |
| 160 | |
| 161 | /* FIXME STATE_SAVE_PT_OFFSET; */ |
| 162 | ti->cpu_context.r1 = (unsigned long)childregs; |
| 163 | /* we should consider the fact that childregs is a copy of the parent |
| 164 | * regs which were saved immediately after entering the kernel state |
| 165 | * before enabling VM. This MSR will be restored in switch_to and |
| 166 | * RETURN() and we want to have the right machine state there |
| 167 | * specifically this state must have INTs disabled before and enabled |
| 168 | * after performing rtbd |
| 169 | * compose the right MSR for RETURN(). It will work for switch_to also |
| 170 | * excepting for VM and UMS |
| 171 | * don't touch UMS , CARRY and cache bits |
| 172 | * right now MSR is a copy of parent one */ |
| 173 | childregs->msr |= MSR_BIP; |
| 174 | childregs->msr &= ~MSR_EIP; |
| 175 | childregs->msr |= MSR_IE; |
| 176 | childregs->msr &= ~MSR_VM; |
| 177 | childregs->msr |= MSR_VMS; |
| 178 | childregs->msr |= MSR_EE; /* exceptions will be enabled*/ |
| 179 | |
| 180 | ti->cpu_context.msr = (childregs->msr|MSR_VM); |
| 181 | ti->cpu_context.msr &= ~MSR_UMS; /* switch_to to kernel mode */ |
| 182 | ti->cpu_context.msr &= ~MSR_IE; |
| 183 | #endif |
| 184 | ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8; |
| 185 | |
| 186 | if (clone_flags & CLONE_SETTLS) |
| 187 | ; |
| 188 | |
| 189 | return 0; |
| 190 | } |
| 191 | |
| 192 | #ifndef CONFIG_MMU |
| 193 | /* |
| 194 | * Return saved PC of a blocked thread. |
| 195 | */ |
| 196 | unsigned long thread_saved_pc(struct task_struct *tsk) |
| 197 | { |
| 198 | struct cpu_context *ctx = |
| 199 | &(((struct thread_info *)(tsk->stack))->cpu_context); |
| 200 | |
| 201 | /* Check whether the thread is blocked in resume() */ |
| 202 | if (in_sched_functions(ctx->r15)) |
| 203 | return (unsigned long)ctx->r15; |
| 204 | else |
| 205 | return ctx->r14; |
| 206 | } |
| 207 | #endif |
| 208 | |
| 209 | static void kernel_thread_helper(int (*fn)(void *), void *arg) |
| 210 | { |
| 211 | fn(arg); |
| 212 | do_exit(-1); |
| 213 | } |
| 214 | |
| 215 | int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) |
| 216 | { |
| 217 | struct pt_regs regs; |
| 218 | |
| 219 | memset(®s, 0, sizeof(regs)); |
| 220 | /* store them in non-volatile registers */ |
| 221 | regs.r5 = (unsigned long)fn; |
| 222 | regs.r6 = (unsigned long)arg; |
| 223 | local_save_flags(regs.msr); |
| 224 | regs.pc = (unsigned long)kernel_thread_helper; |
| 225 | regs.pt_mode = 1; |
| 226 | |
| 227 | return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, |
| 228 | ®s, 0, NULL, NULL); |
| 229 | } |
| 230 | EXPORT_SYMBOL_GPL(kernel_thread); |
| 231 | |
| 232 | unsigned long get_wchan(struct task_struct *p) |
| 233 | { |
| 234 | /* TBD (used by procfs) */ |
| 235 | return 0; |
| 236 | } |
| 237 | |
| 238 | /* Set up a thread for executing a new program */ |
| 239 | void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp) |
| 240 | { |
| 241 | regs->pc = pc; |
| 242 | regs->r1 = usp; |
| 243 | regs->pt_mode = 0; |
| 244 | #ifdef CONFIG_MMU |
| 245 | regs->msr |= MSR_UMS; |
| 246 | #endif |
| 247 | } |
| 248 | |
| 249 | #ifdef CONFIG_MMU |
| 250 | #include <linux/elfcore.h> |
| 251 | /* |
| 252 | * Set up a thread for executing a new program |
| 253 | */ |
| 254 | int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs) |
| 255 | { |
| 256 | return 0; /* MicroBlaze has no separate FPU registers */ |
| 257 | } |
| 258 | #endif /* CONFIG_MMU */ |