Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * arch/s390/kernel/process.c |
| 3 | * |
| 4 | * S390 version |
| 5 | * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation |
| 6 | * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), |
| 7 | * Hartmut Penner (hp@de.ibm.com), |
| 8 | * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com), |
| 9 | * |
| 10 | * Derived from "arch/i386/kernel/process.c" |
| 11 | * Copyright (C) 1995, Linus Torvalds |
| 12 | */ |
| 13 | |
| 14 | /* |
| 15 | * This file handles the architecture-dependent parts of process handling.. |
| 16 | */ |
| 17 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | #include <linux/compiler.h> |
| 19 | #include <linux/cpu.h> |
| 20 | #include <linux/errno.h> |
| 21 | #include <linux/sched.h> |
| 22 | #include <linux/kernel.h> |
| 23 | #include <linux/mm.h> |
| 24 | #include <linux/smp.h> |
| 25 | #include <linux/smp_lock.h> |
| 26 | #include <linux/stddef.h> |
| 27 | #include <linux/unistd.h> |
| 28 | #include <linux/ptrace.h> |
| 29 | #include <linux/slab.h> |
| 30 | #include <linux/vmalloc.h> |
| 31 | #include <linux/user.h> |
| 32 | #include <linux/a.out.h> |
| 33 | #include <linux/interrupt.h> |
| 34 | #include <linux/delay.h> |
| 35 | #include <linux/reboot.h> |
| 36 | #include <linux/init.h> |
| 37 | #include <linux/module.h> |
| 38 | #include <linux/notifier.h> |
| 39 | |
| 40 | #include <asm/uaccess.h> |
| 41 | #include <asm/pgtable.h> |
| 42 | #include <asm/system.h> |
| 43 | #include <asm/io.h> |
| 44 | #include <asm/processor.h> |
| 45 | #include <asm/irq.h> |
| 46 | #include <asm/timer.h> |
| 47 | |
Martin Schwidefsky | 94c12cc | 2006-09-28 16:56:43 +0200 | [diff] [blame] | 48 | asmlinkage void ret_from_fork(void) asm ("ret_from_fork"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | |
| 50 | /* |
| 51 | * Return saved PC of a blocked thread. used in kernel/sched. |
| 52 | * resume in entry.S does not create a new stack frame, it |
| 53 | * just stores the registers %r6-%r15 to the frame given by |
| 54 | * schedule. We want to return the address of the caller of |
| 55 | * schedule, so we have to walk the backchain one time to |
| 56 | * find the frame schedule() store its return address. |
| 57 | */ |
| 58 | unsigned long thread_saved_pc(struct task_struct *tsk) |
| 59 | { |
Heiko Carstens | eb33c19 | 2006-01-14 13:20:57 -0800 | [diff] [blame] | 60 | struct stack_frame *sf, *low, *high; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | |
Heiko Carstens | eb33c19 | 2006-01-14 13:20:57 -0800 | [diff] [blame] | 62 | if (!tsk || !task_stack_page(tsk)) |
| 63 | return 0; |
| 64 | low = task_stack_page(tsk); |
| 65 | high = (struct stack_frame *) task_pt_regs(tsk); |
| 66 | sf = (struct stack_frame *) (tsk->thread.ksp & PSW_ADDR_INSN); |
| 67 | if (sf <= low || sf > high) |
| 68 | return 0; |
| 69 | sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN); |
| 70 | if (sf <= low || sf > high) |
| 71 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | return sf->gprs[8]; |
| 73 | } |
| 74 | |
| 75 | /* |
| 76 | * Need to know about CPUs going idle? |
| 77 | */ |
Alan Stern | e041c68 | 2006-03-27 01:16:30 -0800 | [diff] [blame] | 78 | static ATOMIC_NOTIFIER_HEAD(idle_chain); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | |
| 80 | int register_idle_notifier(struct notifier_block *nb) |
| 81 | { |
Alan Stern | e041c68 | 2006-03-27 01:16:30 -0800 | [diff] [blame] | 82 | return atomic_notifier_chain_register(&idle_chain, nb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | } |
| 84 | EXPORT_SYMBOL(register_idle_notifier); |
| 85 | |
| 86 | int unregister_idle_notifier(struct notifier_block *nb) |
| 87 | { |
Alan Stern | e041c68 | 2006-03-27 01:16:30 -0800 | [diff] [blame] | 88 | return atomic_notifier_chain_unregister(&idle_chain, nb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | } |
| 90 | EXPORT_SYMBOL(unregister_idle_notifier); |
| 91 | |
| 92 | void do_monitor_call(struct pt_regs *regs, long interruption_code) |
| 93 | { |
| 94 | /* disable monitor call class 0 */ |
| 95 | __ctl_clear_bit(8, 15); |
| 96 | |
Alan Stern | e041c68 | 2006-03-27 01:16:30 -0800 | [diff] [blame] | 97 | atomic_notifier_call_chain(&idle_chain, CPU_NOT_IDLE, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | (void *)(long) smp_processor_id()); |
| 99 | } |
| 100 | |
Heiko Carstens | 77fa224 | 2005-06-25 14:55:30 -0700 | [diff] [blame] | 101 | extern void s390_handle_mcck(void); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | /* |
| 103 | * The idle loop on a S390... |
| 104 | */ |
Adrian Bunk | cdb0452 | 2006-03-24 03:15:57 -0800 | [diff] [blame] | 105 | static void default_idle(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | int cpu, rc; |
| 108 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | /* CPU is going idle. */ |
| 110 | cpu = smp_processor_id(); |
Nick Piggin | 64c7c8f | 2005-11-08 21:39:04 -0800 | [diff] [blame] | 111 | |
| 112 | local_irq_disable(); |
| 113 | if (need_resched()) { |
| 114 | local_irq_enable(); |
| 115 | return; |
| 116 | } |
| 117 | |
Alan Stern | e041c68 | 2006-03-27 01:16:30 -0800 | [diff] [blame] | 118 | rc = atomic_notifier_call_chain(&idle_chain, |
| 119 | CPU_IDLE, (void *)(long) cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | if (rc != NOTIFY_OK && rc != NOTIFY_DONE) |
| 121 | BUG(); |
| 122 | if (rc != NOTIFY_OK) { |
| 123 | local_irq_enable(); |
| 124 | return; |
| 125 | } |
| 126 | |
| 127 | /* enable monitor call class 0 */ |
| 128 | __ctl_set_bit(8, 15); |
| 129 | |
| 130 | #ifdef CONFIG_HOTPLUG_CPU |
Heiko Carstens | 1fca251 | 2006-02-17 13:52:46 -0800 | [diff] [blame] | 131 | if (cpu_is_offline(cpu)) { |
| 132 | preempt_enable_no_resched(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | cpu_die(); |
Heiko Carstens | 1fca251 | 2006-02-17 13:52:46 -0800 | [diff] [blame] | 134 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | #endif |
| 136 | |
Heiko Carstens | 77fa224 | 2005-06-25 14:55:30 -0700 | [diff] [blame] | 137 | local_mcck_disable(); |
| 138 | if (test_thread_flag(TIF_MCCK_PENDING)) { |
| 139 | local_mcck_enable(); |
| 140 | local_irq_enable(); |
| 141 | s390_handle_mcck(); |
| 142 | return; |
| 143 | } |
| 144 | |
Heiko Carstens | 1f194a4 | 2006-07-03 00:24:46 -0700 | [diff] [blame] | 145 | trace_hardirqs_on(); |
Heiko Carstens | 77fa224 | 2005-06-25 14:55:30 -0700 | [diff] [blame] | 146 | /* Wait for external, I/O or machine check interrupt. */ |
| 147 | __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_WAIT | |
| 148 | PSW_MASK_IO | PSW_MASK_EXT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | } |
| 150 | |
| 151 | void cpu_idle(void) |
| 152 | { |
Nick Piggin | 5bfb5d6 | 2005-11-08 21:39:01 -0800 | [diff] [blame] | 153 | for (;;) { |
| 154 | while (!need_resched()) |
| 155 | default_idle(); |
| 156 | |
| 157 | preempt_enable_no_resched(); |
| 158 | schedule(); |
| 159 | preempt_disable(); |
| 160 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | } |
| 162 | |
| 163 | void show_regs(struct pt_regs *regs) |
| 164 | { |
| 165 | struct task_struct *tsk = current; |
| 166 | |
Al Viro | 30af712 | 2006-01-12 01:05:50 -0800 | [diff] [blame] | 167 | printk("CPU: %d %s\n", task_thread_info(tsk)->cpu, print_tainted()); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | printk("Process %s (pid: %d, task: %p, ksp: %p)\n", |
| 169 | current->comm, current->pid, (void *) tsk, |
| 170 | (void *) tsk->thread.ksp); |
| 171 | |
| 172 | show_registers(regs); |
| 173 | /* Show stack backtrace if pt_regs is from kernel mode */ |
| 174 | if (!(regs->psw.mask & PSW_MASK_PSTATE)) |
Heiko Carstens | d2c993d | 2006-07-12 16:41:55 +0200 | [diff] [blame] | 175 | show_trace(NULL, (unsigned long *) regs->gprs[15]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 176 | } |
| 177 | |
| 178 | extern void kernel_thread_starter(void); |
| 179 | |
Martin Schwidefsky | 94c12cc | 2006-09-28 16:56:43 +0200 | [diff] [blame] | 180 | asm( |
| 181 | ".align 4\n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 182 | "kernel_thread_starter:\n" |
| 183 | " la 2,0(10)\n" |
| 184 | " basr 14,9\n" |
| 185 | " la 2,0\n" |
| 186 | " br 11\n"); |
| 187 | |
| 188 | int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) |
| 189 | { |
| 190 | struct pt_regs regs; |
| 191 | |
| 192 | memset(®s, 0, sizeof(regs)); |
| 193 | regs.psw.mask = PSW_KERNEL_BITS | PSW_MASK_IO | PSW_MASK_EXT; |
| 194 | regs.psw.addr = (unsigned long) kernel_thread_starter | PSW_ADDR_AMODE; |
| 195 | regs.gprs[9] = (unsigned long) fn; |
| 196 | regs.gprs[10] = (unsigned long) arg; |
| 197 | regs.gprs[11] = (unsigned long) do_exit; |
| 198 | regs.orig_gpr2 = -1; |
| 199 | |
| 200 | /* Ok, create the new process.. */ |
| 201 | return do_fork(flags | CLONE_VM | CLONE_UNTRACED, |
| 202 | 0, ®s, 0, NULL, NULL); |
| 203 | } |
| 204 | |
| 205 | /* |
| 206 | * Free current thread data structures etc.. |
| 207 | */ |
| 208 | void exit_thread(void) |
| 209 | { |
| 210 | } |
| 211 | |
| 212 | void flush_thread(void) |
| 213 | { |
| 214 | clear_used_math(); |
| 215 | clear_tsk_thread_flag(current, TIF_USEDFPU); |
| 216 | } |
| 217 | |
| 218 | void release_thread(struct task_struct *dead_task) |
| 219 | { |
| 220 | } |
| 221 | |
| 222 | int copy_thread(int nr, unsigned long clone_flags, unsigned long new_stackp, |
| 223 | unsigned long unused, |
| 224 | struct task_struct * p, struct pt_regs * regs) |
| 225 | { |
| 226 | struct fake_frame |
| 227 | { |
| 228 | struct stack_frame sf; |
| 229 | struct pt_regs childregs; |
| 230 | } *frame; |
| 231 | |
Al Viro | c7584fb | 2006-01-12 01:05:49 -0800 | [diff] [blame] | 232 | frame = container_of(task_pt_regs(p), struct fake_frame, childregs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 233 | p->thread.ksp = (unsigned long) frame; |
| 234 | /* Store access registers to kernel stack of new process. */ |
| 235 | frame->childregs = *regs; |
| 236 | frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */ |
| 237 | frame->childregs.gprs[15] = new_stackp; |
| 238 | frame->sf.back_chain = 0; |
| 239 | |
| 240 | /* new return point is ret_from_fork */ |
| 241 | frame->sf.gprs[8] = (unsigned long) ret_from_fork; |
| 242 | |
| 243 | /* fake return stack for resume(), don't go back to schedule */ |
| 244 | frame->sf.gprs[9] = (unsigned long) frame; |
| 245 | |
| 246 | /* Save access registers to new thread structure. */ |
| 247 | save_access_regs(&p->thread.acrs[0]); |
| 248 | |
Martin Schwidefsky | 347a8dc | 2006-01-06 00:19:28 -0800 | [diff] [blame] | 249 | #ifndef CONFIG_64BIT |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 250 | /* |
| 251 | * save fprs to current->thread.fp_regs to merge them with |
| 252 | * the emulated registers and then copy the result to the child. |
| 253 | */ |
| 254 | save_fp_regs(¤t->thread.fp_regs); |
| 255 | memcpy(&p->thread.fp_regs, ¤t->thread.fp_regs, |
| 256 | sizeof(s390_fp_regs)); |
| 257 | p->thread.user_seg = __pa((unsigned long) p->mm->pgd) | _SEGMENT_TABLE; |
| 258 | /* Set a new TLS ? */ |
| 259 | if (clone_flags & CLONE_SETTLS) |
| 260 | p->thread.acrs[0] = regs->gprs[6]; |
Martin Schwidefsky | 347a8dc | 2006-01-06 00:19:28 -0800 | [diff] [blame] | 261 | #else /* CONFIG_64BIT */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | /* Save the fpu registers to new thread structure. */ |
| 263 | save_fp_regs(&p->thread.fp_regs); |
| 264 | p->thread.user_seg = __pa((unsigned long) p->mm->pgd) | _REGION_TABLE; |
| 265 | /* Set a new TLS ? */ |
| 266 | if (clone_flags & CLONE_SETTLS) { |
| 267 | if (test_thread_flag(TIF_31BIT)) { |
| 268 | p->thread.acrs[0] = (unsigned int) regs->gprs[6]; |
| 269 | } else { |
| 270 | p->thread.acrs[0] = (unsigned int)(regs->gprs[6] >> 32); |
| 271 | p->thread.acrs[1] = (unsigned int) regs->gprs[6]; |
| 272 | } |
| 273 | } |
Martin Schwidefsky | 347a8dc | 2006-01-06 00:19:28 -0800 | [diff] [blame] | 274 | #endif /* CONFIG_64BIT */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 275 | /* start new process with ar4 pointing to the correct address space */ |
| 276 | p->thread.mm_segment = get_fs(); |
| 277 | /* Don't copy debug registers */ |
| 278 | memset(&p->thread.per_info,0,sizeof(p->thread.per_info)); |
| 279 | |
| 280 | return 0; |
| 281 | } |
| 282 | |
| 283 | asmlinkage long sys_fork(struct pt_regs regs) |
| 284 | { |
| 285 | return do_fork(SIGCHLD, regs.gprs[15], ®s, 0, NULL, NULL); |
| 286 | } |
| 287 | |
| 288 | asmlinkage long sys_clone(struct pt_regs regs) |
| 289 | { |
| 290 | unsigned long clone_flags; |
| 291 | unsigned long newsp; |
| 292 | int __user *parent_tidptr, *child_tidptr; |
| 293 | |
| 294 | clone_flags = regs.gprs[3]; |
| 295 | newsp = regs.orig_gpr2; |
| 296 | parent_tidptr = (int __user *) regs.gprs[4]; |
| 297 | child_tidptr = (int __user *) regs.gprs[5]; |
| 298 | if (!newsp) |
| 299 | newsp = regs.gprs[15]; |
| 300 | return do_fork(clone_flags, newsp, ®s, 0, |
| 301 | parent_tidptr, child_tidptr); |
| 302 | } |
| 303 | |
| 304 | /* |
| 305 | * This is trivial, and on the face of it looks like it |
| 306 | * could equally well be done in user mode. |
| 307 | * |
| 308 | * Not so, for quite unobvious reasons - register pressure. |
| 309 | * In user mode vfork() cannot have a stack frame, and if |
| 310 | * done by calling the "clone()" system call directly, you |
| 311 | * do not have enough call-clobbered registers to hold all |
| 312 | * the information you need. |
| 313 | */ |
| 314 | asmlinkage long sys_vfork(struct pt_regs regs) |
| 315 | { |
| 316 | return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, |
| 317 | regs.gprs[15], ®s, 0, NULL, NULL); |
| 318 | } |
| 319 | |
| 320 | /* |
| 321 | * sys_execve() executes a new program. |
| 322 | */ |
| 323 | asmlinkage long sys_execve(struct pt_regs regs) |
| 324 | { |
| 325 | int error; |
| 326 | char * filename; |
| 327 | |
| 328 | filename = getname((char __user *) regs.orig_gpr2); |
| 329 | error = PTR_ERR(filename); |
| 330 | if (IS_ERR(filename)) |
| 331 | goto out; |
| 332 | error = do_execve(filename, (char __user * __user *) regs.gprs[3], |
| 333 | (char __user * __user *) regs.gprs[4], ®s); |
| 334 | if (error == 0) { |
| 335 | task_lock(current); |
| 336 | current->ptrace &= ~PT_DTRACE; |
| 337 | task_unlock(current); |
| 338 | current->thread.fp_regs.fpc = 0; |
| 339 | if (MACHINE_HAS_IEEE) |
| 340 | asm volatile("sfpc %0,%0" : : "d" (0)); |
| 341 | } |
| 342 | putname(filename); |
| 343 | out: |
| 344 | return error; |
| 345 | } |
| 346 | |
| 347 | |
| 348 | /* |
| 349 | * fill in the FPU structure for a core dump. |
| 350 | */ |
| 351 | int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs) |
| 352 | { |
Martin Schwidefsky | 347a8dc | 2006-01-06 00:19:28 -0800 | [diff] [blame] | 353 | #ifndef CONFIG_64BIT |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 354 | /* |
| 355 | * save fprs to current->thread.fp_regs to merge them with |
| 356 | * the emulated registers and then copy the result to the dump. |
| 357 | */ |
| 358 | save_fp_regs(¤t->thread.fp_regs); |
| 359 | memcpy(fpregs, ¤t->thread.fp_regs, sizeof(s390_fp_regs)); |
Martin Schwidefsky | 347a8dc | 2006-01-06 00:19:28 -0800 | [diff] [blame] | 360 | #else /* CONFIG_64BIT */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | save_fp_regs(fpregs); |
Martin Schwidefsky | 347a8dc | 2006-01-06 00:19:28 -0800 | [diff] [blame] | 362 | #endif /* CONFIG_64BIT */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | return 1; |
| 364 | } |
| 365 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 366 | unsigned long get_wchan(struct task_struct *p) |
| 367 | { |
| 368 | struct stack_frame *sf, *low, *high; |
| 369 | unsigned long return_address; |
| 370 | int count; |
| 371 | |
Al Viro | 30af712 | 2006-01-12 01:05:50 -0800 | [diff] [blame] | 372 | if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 373 | return 0; |
Al Viro | 30af712 | 2006-01-12 01:05:50 -0800 | [diff] [blame] | 374 | low = task_stack_page(p); |
| 375 | high = (struct stack_frame *) task_pt_regs(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 376 | sf = (struct stack_frame *) (p->thread.ksp & PSW_ADDR_INSN); |
| 377 | if (sf <= low || sf > high) |
| 378 | return 0; |
| 379 | for (count = 0; count < 16; count++) { |
| 380 | sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN); |
| 381 | if (sf <= low || sf > high) |
| 382 | return 0; |
| 383 | return_address = sf->gprs[8] & PSW_ADDR_INSN; |
| 384 | if (!in_sched_functions(return_address)) |
| 385 | return return_address; |
| 386 | } |
| 387 | return 0; |
| 388 | } |
| 389 | |