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