~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/alpha/kernel/process.c

Version: ~ [ linux-5.4-rc3 ] ~ [ linux-5.3.6 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.79 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.149 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.196 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.196 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.75 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  *  linux/arch/alpha/kernel/process.c
  3  *
  4  *  Copyright (C) 1995  Linus Torvalds
  5  */
  6 
  7 /*
  8  * This file handles the architecture-dependent parts of process handling.
  9  */
 10 
 11 #include <linux/errno.h>
 12 #include <linux/module.h>
 13 #include <linux/sched.h>
 14 #include <linux/kernel.h>
 15 #include <linux/mm.h>
 16 #include <linux/smp.h>
 17 #include <linux/stddef.h>
 18 #include <linux/unistd.h>
 19 #include <linux/ptrace.h>
 20 #include <linux/user.h>
 21 #include <linux/time.h>
 22 #include <linux/major.h>
 23 #include <linux/stat.h>
 24 #include <linux/vt.h>
 25 #include <linux/mman.h>
 26 #include <linux/elfcore.h>
 27 #include <linux/reboot.h>
 28 #include <linux/tty.h>
 29 #include <linux/console.h>
 30 #include <linux/slab.h>
 31 #include <linux/rcupdate.h>
 32 
 33 #include <asm/reg.h>
 34 #include <asm/uaccess.h>
 35 #include <asm/io.h>
 36 #include <asm/pgtable.h>
 37 #include <asm/hwrpb.h>
 38 #include <asm/fpu.h>
 39 
 40 #include "proto.h"
 41 #include "pci_impl.h"
 42 
 43 /*
 44  * Power off function, if any
 45  */
 46 void (*pm_power_off)(void) = machine_power_off;
 47 EXPORT_SYMBOL(pm_power_off);
 48 
 49 #ifdef CONFIG_ALPHA_WTINT
 50 /*
 51  * Sleep the CPU.
 52  * EV6, LCA45 and QEMU know how to power down, skipping N timer interrupts.
 53  */
 54 void arch_cpu_idle(void)
 55 {
 56         wtint(0);
 57         local_irq_enable();
 58 }
 59 
 60 void arch_cpu_idle_dead(void)
 61 {
 62         wtint(INT_MAX);
 63 }
 64 #endif /* ALPHA_WTINT */
 65 
 66 struct halt_info {
 67         int mode;
 68         char *restart_cmd;
 69 };
 70 
 71 static void
 72 common_shutdown_1(void *generic_ptr)
 73 {
 74         struct halt_info *how = (struct halt_info *)generic_ptr;
 75         struct percpu_struct *cpup;
 76         unsigned long *pflags, flags;
 77         int cpuid = smp_processor_id();
 78 
 79         /* No point in taking interrupts anymore. */
 80         local_irq_disable();
 81 
 82         cpup = (struct percpu_struct *)
 83                         ((unsigned long)hwrpb + hwrpb->processor_offset
 84                          + hwrpb->processor_size * cpuid);
 85         pflags = &cpup->flags;
 86         flags = *pflags;
 87 
 88         /* Clear reason to "default"; clear "bootstrap in progress". */
 89         flags &= ~0x00ff0001UL;
 90 
 91 #ifdef CONFIG_SMP
 92         /* Secondaries halt here. */
 93         if (cpuid != boot_cpuid) {
 94                 flags |= 0x00040000UL; /* "remain halted" */
 95                 *pflags = flags;
 96                 set_cpu_present(cpuid, false);
 97                 set_cpu_possible(cpuid, false);
 98                 halt();
 99         }
100 #endif
101 
102         if (how->mode == LINUX_REBOOT_CMD_RESTART) {
103                 if (!how->restart_cmd) {
104                         flags |= 0x00020000UL; /* "cold bootstrap" */
105                 } else {
106                         /* For SRM, we could probably set environment
107                            variables to get this to work.  We'd have to
108                            delay this until after srm_paging_stop unless
109                            we ever got srm_fixup working.
110 
111                            At the moment, SRM will use the last boot device,
112                            but the file and flags will be the defaults, when
113                            doing a "warm" bootstrap.  */
114                         flags |= 0x00030000UL; /* "warm bootstrap" */
115                 }
116         } else {
117                 flags |= 0x00040000UL; /* "remain halted" */
118         }
119         *pflags = flags;
120 
121 #ifdef CONFIG_SMP
122         /* Wait for the secondaries to halt. */
123         set_cpu_present(boot_cpuid, false);
124         set_cpu_possible(boot_cpuid, false);
125         while (cpumask_weight(cpu_present_mask))
126                 barrier();
127 #endif
128 
129         /* If booted from SRM, reset some of the original environment. */
130         if (alpha_using_srm) {
131 #ifdef CONFIG_DUMMY_CONSOLE
132                 /* If we've gotten here after SysRq-b, leave interrupt
133                    context before taking over the console. */
134                 if (in_interrupt())
135                         irq_exit();
136                 /* This has the effect of resetting the VGA video origin.  */
137                 console_lock();
138                 do_take_over_console(&dummy_con, 0, MAX_NR_CONSOLES-1, 1);
139                 console_unlock();
140 #endif
141                 pci_restore_srm_config();
142                 set_hae(srm_hae);
143         }
144 
145         if (alpha_mv.kill_arch)
146                 alpha_mv.kill_arch(how->mode);
147 
148         if (! alpha_using_srm && how->mode != LINUX_REBOOT_CMD_RESTART) {
149                 /* Unfortunately, since MILO doesn't currently understand
150                    the hwrpb bits above, we can't reliably halt the 
151                    processor and keep it halted.  So just loop.  */
152                 return;
153         }
154 
155         if (alpha_using_srm)
156                 srm_paging_stop();
157 
158         halt();
159 }
160 
161 static void
162 common_shutdown(int mode, char *restart_cmd)
163 {
164         struct halt_info args;
165         args.mode = mode;
166         args.restart_cmd = restart_cmd;
167         on_each_cpu(common_shutdown_1, &args, 0);
168 }
169 
170 void
171 machine_restart(char *restart_cmd)
172 {
173         common_shutdown(LINUX_REBOOT_CMD_RESTART, restart_cmd);
174 }
175 
176 
177 void
178 machine_halt(void)
179 {
180         common_shutdown(LINUX_REBOOT_CMD_HALT, NULL);
181 }
182 
183 
184 void
185 machine_power_off(void)
186 {
187         common_shutdown(LINUX_REBOOT_CMD_POWER_OFF, NULL);
188 }
189 
190 
191 /* Used by sysrq-p, among others.  I don't believe r9-r15 are ever
192    saved in the context it's used.  */
193 
194 void
195 show_regs(struct pt_regs *regs)
196 {
197         show_regs_print_info(KERN_DEFAULT);
198         dik_show_regs(regs, NULL);
199 }
200 
201 /*
202  * Re-start a thread when doing execve()
203  */
204 void
205 start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
206 {
207         regs->pc = pc;
208         regs->ps = 8;
209         wrusp(sp);
210 }
211 EXPORT_SYMBOL(start_thread);
212 
213 /*
214  * Free current thread data structures etc..
215  */
216 void
217 exit_thread(void)
218 {
219 }
220 
221 void
222 flush_thread(void)
223 {
224         /* Arrange for each exec'ed process to start off with a clean slate
225            with respect to the FPU.  This is all exceptions disabled.  */
226         current_thread_info()->ieee_state = 0;
227         wrfpcr(FPCR_DYN_NORMAL | ieee_swcr_to_fpcr(0));
228 
229         /* Clean slate for TLS.  */
230         current_thread_info()->pcb.unique = 0;
231 }
232 
233 void
234 release_thread(struct task_struct *dead_task)
235 {
236 }
237 
238 /*
239  * Copy architecture-specific thread state
240  */
241 int
242 copy_thread(unsigned long clone_flags, unsigned long usp,
243             unsigned long kthread_arg,
244             struct task_struct *p)
245 {
246         extern void ret_from_fork(void);
247         extern void ret_from_kernel_thread(void);
248 
249         struct thread_info *childti = task_thread_info(p);
250         struct pt_regs *childregs = task_pt_regs(p);
251         struct pt_regs *regs = current_pt_regs();
252         struct switch_stack *childstack, *stack;
253 
254         childstack = ((struct switch_stack *) childregs) - 1;
255         childti->pcb.ksp = (unsigned long) childstack;
256         childti->pcb.flags = 1; /* set FEN, clear everything else */
257 
258         if (unlikely(p->flags & PF_KTHREAD)) {
259                 /* kernel thread */
260                 memset(childstack, 0,
261                         sizeof(struct switch_stack) + sizeof(struct pt_regs));
262                 childstack->r26 = (unsigned long) ret_from_kernel_thread;
263                 childstack->r9 = usp;   /* function */
264                 childstack->r10 = kthread_arg;
265                 childregs->hae = alpha_mv.hae_cache,
266                 childti->pcb.usp = 0;
267                 return 0;
268         }
269         /* Note: if CLONE_SETTLS is not set, then we must inherit the
270            value from the parent, which will have been set by the block
271            copy in dup_task_struct.  This is non-intuitive, but is
272            required for proper operation in the case of a threaded
273            application calling fork.  */
274         if (clone_flags & CLONE_SETTLS)
275                 childti->pcb.unique = regs->r20;
276         childti->pcb.usp = usp ?: rdusp();
277         *childregs = *regs;
278         childregs->r0 = 0;
279         childregs->r19 = 0;
280         childregs->r20 = 1;     /* OSF/1 has some strange fork() semantics.  */
281         regs->r20 = 0;
282         stack = ((struct switch_stack *) regs) - 1;
283         *childstack = *stack;
284         childstack->r26 = (unsigned long) ret_from_fork;
285         return 0;
286 }
287 
288 /*
289  * Fill in the user structure for a ELF core dump.
290  */
291 void
292 dump_elf_thread(elf_greg_t *dest, struct pt_regs *pt, struct thread_info *ti)
293 {
294         /* switch stack follows right below pt_regs: */
295         struct switch_stack * sw = ((struct switch_stack *) pt) - 1;
296 
297         dest[ 0] = pt->r0;
298         dest[ 1] = pt->r1;
299         dest[ 2] = pt->r2;
300         dest[ 3] = pt->r3;
301         dest[ 4] = pt->r4;
302         dest[ 5] = pt->r5;
303         dest[ 6] = pt->r6;
304         dest[ 7] = pt->r7;
305         dest[ 8] = pt->r8;
306         dest[ 9] = sw->r9;
307         dest[10] = sw->r10;
308         dest[11] = sw->r11;
309         dest[12] = sw->r12;
310         dest[13] = sw->r13;
311         dest[14] = sw->r14;
312         dest[15] = sw->r15;
313         dest[16] = pt->r16;
314         dest[17] = pt->r17;
315         dest[18] = pt->r18;
316         dest[19] = pt->r19;
317         dest[20] = pt->r20;
318         dest[21] = pt->r21;
319         dest[22] = pt->r22;
320         dest[23] = pt->r23;
321         dest[24] = pt->r24;
322         dest[25] = pt->r25;
323         dest[26] = pt->r26;
324         dest[27] = pt->r27;
325         dest[28] = pt->r28;
326         dest[29] = pt->gp;
327         dest[30] = ti == current_thread_info() ? rdusp() : ti->pcb.usp;
328         dest[31] = pt->pc;
329 
330         /* Once upon a time this was the PS value.  Which is stupid
331            since that is always 8 for usermode.  Usurped for the more
332            useful value of the thread's UNIQUE field.  */
333         dest[32] = ti->pcb.unique;
334 }
335 EXPORT_SYMBOL(dump_elf_thread);
336 
337 int
338 dump_elf_task(elf_greg_t *dest, struct task_struct *task)
339 {
340         dump_elf_thread(dest, task_pt_regs(task), task_thread_info(task));
341         return 1;
342 }
343 EXPORT_SYMBOL(dump_elf_task);
344 
345 int
346 dump_elf_task_fp(elf_fpreg_t *dest, struct task_struct *task)
347 {
348         struct switch_stack *sw = (struct switch_stack *)task_pt_regs(task) - 1;
349         memcpy(dest, sw->fp, 32 * 8);
350         return 1;
351 }
352 EXPORT_SYMBOL(dump_elf_task_fp);
353 
354 /*
355  * Return saved PC of a blocked thread.  This assumes the frame
356  * pointer is the 6th saved long on the kernel stack and that the
357  * saved return address is the first long in the frame.  This all
358  * holds provided the thread blocked through a call to schedule() ($15
359  * is the frame pointer in schedule() and $15 is saved at offset 48 by
360  * entry.S:do_switch_stack).
361  *
362  * Under heavy swap load I've seen this lose in an ugly way.  So do
363  * some extra sanity checking on the ranges we expect these pointers
364  * to be in so that we can fail gracefully.  This is just for ps after
365  * all.  -- r~
366  */
367 
368 unsigned long
369 thread_saved_pc(struct task_struct *t)
370 {
371         unsigned long base = (unsigned long)task_stack_page(t);
372         unsigned long fp, sp = task_thread_info(t)->pcb.ksp;
373 
374         if (sp > base && sp+6*8 < base + 16*1024) {
375                 fp = ((unsigned long*)sp)[6];
376                 if (fp > sp && fp < base + 16*1024)
377                         return *(unsigned long *)fp;
378         }
379 
380         return 0;
381 }
382 
383 unsigned long
384 get_wchan(struct task_struct *p)
385 {
386         unsigned long schedule_frame;
387         unsigned long pc;
388         if (!p || p == current || p->state == TASK_RUNNING)
389                 return 0;
390         /*
391          * This one depends on the frame size of schedule().  Do a
392          * "disass schedule" in gdb to find the frame size.  Also, the
393          * code assumes that sleep_on() follows immediately after
394          * interruptible_sleep_on() and that add_timer() follows
395          * immediately after interruptible_sleep().  Ugly, isn't it?
396          * Maybe adding a wchan field to task_struct would be better,
397          * after all...
398          */
399 
400         pc = thread_saved_pc(p);
401         if (in_sched_functions(pc)) {
402                 schedule_frame = ((unsigned long *)task_thread_info(p)->pcb.ksp)[6];
403                 return ((unsigned long *)schedule_frame)[12];
404         }
405         return pc;
406 }
407 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp