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867e359b CM |
1 | /* |
2 | * Copyright 2010 Tilera Corporation. All Rights Reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation, version 2. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, but | |
9 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or | |
11 | * NON INFRINGEMENT. See the GNU General Public License for | |
12 | * more details. | |
13 | */ | |
14 | ||
15 | #include <linux/sched.h> | |
16 | #include <linux/preempt.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/fs.h> | |
19 | #include <linux/kprobes.h> | |
20 | #include <linux/elfcore.h> | |
21 | #include <linux/tick.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/mm.h> | |
24 | #include <linux/compat.h> | |
25 | #include <linux/hardirq.h> | |
26 | #include <linux/syscalls.h> | |
0707ad30 | 27 | #include <linux/kernel.h> |
867e359b CM |
28 | #include <asm/system.h> |
29 | #include <asm/stack.h> | |
30 | #include <asm/homecache.h> | |
0707ad30 CM |
31 | #include <asm/syscalls.h> |
32 | #ifdef CONFIG_HARDWALL | |
33 | #include <asm/hardwall.h> | |
34 | #endif | |
867e359b CM |
35 | #include <arch/chip.h> |
36 | #include <arch/abi.h> | |
37 | ||
38 | ||
39 | /* | |
40 | * Use the (x86) "idle=poll" option to prefer low latency when leaving the | |
41 | * idle loop over low power while in the idle loop, e.g. if we have | |
42 | * one thread per core and we want to get threads out of futex waits fast. | |
43 | */ | |
44 | static int no_idle_nap; | |
45 | static int __init idle_setup(char *str) | |
46 | { | |
47 | if (!str) | |
48 | return -EINVAL; | |
49 | ||
50 | if (!strcmp(str, "poll")) { | |
0707ad30 | 51 | pr_info("using polling idle threads.\n"); |
867e359b CM |
52 | no_idle_nap = 1; |
53 | } else if (!strcmp(str, "halt")) | |
54 | no_idle_nap = 0; | |
55 | else | |
56 | return -1; | |
57 | ||
58 | return 0; | |
59 | } | |
60 | early_param("idle", idle_setup); | |
61 | ||
62 | /* | |
63 | * The idle thread. There's no useful work to be | |
64 | * done, so just try to conserve power and have a | |
65 | * low exit latency (ie sit in a loop waiting for | |
66 | * somebody to say that they'd like to reschedule) | |
67 | */ | |
68 | void cpu_idle(void) | |
69 | { | |
867e359b CM |
70 | int cpu = smp_processor_id(); |
71 | ||
72 | ||
73 | current_thread_info()->status |= TS_POLLING; | |
74 | ||
75 | if (no_idle_nap) { | |
76 | while (1) { | |
77 | while (!need_resched()) | |
78 | cpu_relax(); | |
79 | schedule(); | |
80 | } | |
81 | } | |
82 | ||
83 | /* endless idle loop with no priority at all */ | |
84 | while (1) { | |
85 | tick_nohz_stop_sched_tick(1); | |
86 | while (!need_resched()) { | |
87 | if (cpu_is_offline(cpu)) | |
88 | BUG(); /* no HOTPLUG_CPU */ | |
89 | ||
90 | local_irq_disable(); | |
91 | __get_cpu_var(irq_stat).idle_timestamp = jiffies; | |
92 | current_thread_info()->status &= ~TS_POLLING; | |
93 | /* | |
94 | * TS_POLLING-cleared state must be visible before we | |
95 | * test NEED_RESCHED: | |
96 | */ | |
97 | smp_mb(); | |
98 | ||
99 | if (!need_resched()) | |
100 | _cpu_idle(); | |
101 | else | |
102 | local_irq_enable(); | |
103 | current_thread_info()->status |= TS_POLLING; | |
104 | } | |
105 | tick_nohz_restart_sched_tick(); | |
106 | preempt_enable_no_resched(); | |
107 | schedule(); | |
108 | preempt_disable(); | |
109 | } | |
110 | } | |
111 | ||
112 | struct thread_info *alloc_thread_info(struct task_struct *task) | |
113 | { | |
114 | struct page *page; | |
0707ad30 | 115 | gfp_t flags = GFP_KERNEL; |
867e359b CM |
116 | |
117 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
118 | flags |= __GFP_ZERO; | |
119 | #endif | |
120 | ||
121 | page = alloc_pages(flags, THREAD_SIZE_ORDER); | |
122 | if (!page) | |
0707ad30 | 123 | return NULL; |
867e359b CM |
124 | |
125 | return (struct thread_info *)page_address(page); | |
126 | } | |
127 | ||
128 | /* | |
129 | * Free a thread_info node, and all of its derivative | |
130 | * data structures. | |
131 | */ | |
132 | void free_thread_info(struct thread_info *info) | |
133 | { | |
134 | struct single_step_state *step_state = info->step_state; | |
135 | ||
0707ad30 CM |
136 | #ifdef CONFIG_HARDWALL |
137 | /* | |
138 | * We free a thread_info from the context of the task that has | |
139 | * been scheduled next, so the original task is already dead. | |
140 | * Calling deactivate here just frees up the data structures. | |
141 | * If the task we're freeing held the last reference to a | |
142 | * hardwall fd, it would have been released prior to this point | |
143 | * anyway via exit_files(), and "hardwall" would be NULL by now. | |
144 | */ | |
145 | if (info->task->thread.hardwall) | |
146 | hardwall_deactivate(info->task); | |
147 | #endif | |
867e359b CM |
148 | |
149 | if (step_state) { | |
150 | ||
151 | /* | |
152 | * FIXME: we don't munmap step_state->buffer | |
153 | * because the mm_struct for this process (info->task->mm) | |
154 | * has already been zeroed in exit_mm(). Keeping a | |
155 | * reference to it here seems like a bad move, so this | |
156 | * means we can't munmap() the buffer, and therefore if we | |
157 | * ptrace multiple threads in a process, we will slowly | |
158 | * leak user memory. (Note that as soon as the last | |
159 | * thread in a process dies, we will reclaim all user | |
160 | * memory including single-step buffers in the usual way.) | |
161 | * We should either assign a kernel VA to this buffer | |
162 | * somehow, or we should associate the buffer(s) with the | |
163 | * mm itself so we can clean them up that way. | |
164 | */ | |
165 | kfree(step_state); | |
166 | } | |
167 | ||
168 | free_page((unsigned long)info); | |
169 | } | |
170 | ||
171 | static void save_arch_state(struct thread_struct *t); | |
172 | ||
867e359b CM |
173 | int copy_thread(unsigned long clone_flags, unsigned long sp, |
174 | unsigned long stack_size, | |
175 | struct task_struct *p, struct pt_regs *regs) | |
176 | { | |
177 | struct pt_regs *childregs; | |
178 | unsigned long ksp; | |
179 | ||
180 | /* | |
181 | * When creating a new kernel thread we pass sp as zero. | |
182 | * Assign it to a reasonable value now that we have the stack. | |
183 | */ | |
184 | if (sp == 0 && regs->ex1 == PL_ICS_EX1(KERNEL_PL, 0)) | |
185 | sp = KSTK_TOP(p); | |
186 | ||
187 | /* | |
188 | * Do not clone step state from the parent; each thread | |
189 | * must make its own lazily. | |
190 | */ | |
191 | task_thread_info(p)->step_state = NULL; | |
192 | ||
193 | /* | |
194 | * Start new thread in ret_from_fork so it schedules properly | |
195 | * and then return from interrupt like the parent. | |
196 | */ | |
197 | p->thread.pc = (unsigned long) ret_from_fork; | |
198 | ||
199 | /* Save user stack top pointer so we can ID the stack vm area later. */ | |
200 | p->thread.usp0 = sp; | |
201 | ||
202 | /* Record the pid of the process that created this one. */ | |
203 | p->thread.creator_pid = current->pid; | |
204 | ||
205 | /* | |
206 | * Copy the registers onto the kernel stack so the | |
207 | * return-from-interrupt code will reload it into registers. | |
208 | */ | |
209 | childregs = task_pt_regs(p); | |
210 | *childregs = *regs; | |
211 | childregs->regs[0] = 0; /* return value is zero */ | |
212 | childregs->sp = sp; /* override with new user stack pointer */ | |
213 | ||
214 | /* | |
215 | * Copy the callee-saved registers from the passed pt_regs struct | |
216 | * into the context-switch callee-saved registers area. | |
217 | * We have to restore the callee-saved registers since we may | |
218 | * be cloning a userspace task with userspace register state, | |
219 | * and we won't be unwinding the same kernel frames to restore them. | |
220 | * Zero out the C ABI save area to mark the top of the stack. | |
221 | */ | |
222 | ksp = (unsigned long) childregs; | |
223 | ksp -= C_ABI_SAVE_AREA_SIZE; /* interrupt-entry save area */ | |
224 | ((long *)ksp)[0] = ((long *)ksp)[1] = 0; | |
225 | ksp -= CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long); | |
226 | memcpy((void *)ksp, ®s->regs[CALLEE_SAVED_FIRST_REG], | |
227 | CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long)); | |
228 | ksp -= C_ABI_SAVE_AREA_SIZE; /* __switch_to() save area */ | |
229 | ((long *)ksp)[0] = ((long *)ksp)[1] = 0; | |
230 | p->thread.ksp = ksp; | |
231 | ||
232 | #if CHIP_HAS_TILE_DMA() | |
233 | /* | |
234 | * No DMA in the new thread. We model this on the fact that | |
235 | * fork() clears the pending signals, alarms, and aio for the child. | |
236 | */ | |
237 | memset(&p->thread.tile_dma_state, 0, sizeof(struct tile_dma_state)); | |
238 | memset(&p->thread.dma_async_tlb, 0, sizeof(struct async_tlb)); | |
239 | #endif | |
240 | ||
241 | #if CHIP_HAS_SN_PROC() | |
242 | /* Likewise, the new thread is not running static processor code. */ | |
243 | p->thread.sn_proc_running = 0; | |
244 | memset(&p->thread.sn_async_tlb, 0, sizeof(struct async_tlb)); | |
245 | #endif | |
246 | ||
247 | #if CHIP_HAS_PROC_STATUS_SPR() | |
248 | /* New thread has its miscellaneous processor state bits clear. */ | |
249 | p->thread.proc_status = 0; | |
250 | #endif | |
251 | ||
0707ad30 CM |
252 | #ifdef CONFIG_HARDWALL |
253 | /* New thread does not own any networks. */ | |
254 | p->thread.hardwall = NULL; | |
255 | #endif | |
867e359b CM |
256 | |
257 | ||
258 | /* | |
259 | * Start the new thread with the current architecture state | |
260 | * (user interrupt masks, etc.). | |
261 | */ | |
262 | save_arch_state(&p->thread); | |
263 | ||
264 | return 0; | |
265 | } | |
266 | ||
267 | /* | |
268 | * Return "current" if it looks plausible, or else a pointer to a dummy. | |
269 | * This can be helpful if we are just trying to emit a clean panic. | |
270 | */ | |
271 | struct task_struct *validate_current(void) | |
272 | { | |
273 | static struct task_struct corrupt = { .comm = "<corrupt>" }; | |
274 | struct task_struct *tsk = current; | |
275 | if (unlikely((unsigned long)tsk < PAGE_OFFSET || | |
276 | (void *)tsk > high_memory || | |
277 | ((unsigned long)tsk & (__alignof__(*tsk) - 1)) != 0)) { | |
0707ad30 | 278 | pr_err("Corrupt 'current' %p (sp %#lx)\n", tsk, stack_pointer); |
867e359b CM |
279 | tsk = &corrupt; |
280 | } | |
281 | return tsk; | |
282 | } | |
283 | ||
284 | /* Take and return the pointer to the previous task, for schedule_tail(). */ | |
285 | struct task_struct *sim_notify_fork(struct task_struct *prev) | |
286 | { | |
287 | struct task_struct *tsk = current; | |
288 | __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_FORK_PARENT | | |
289 | (tsk->thread.creator_pid << _SIM_CONTROL_OPERATOR_BITS)); | |
290 | __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_FORK | | |
291 | (tsk->pid << _SIM_CONTROL_OPERATOR_BITS)); | |
292 | return prev; | |
293 | } | |
294 | ||
295 | int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs) | |
296 | { | |
297 | struct pt_regs *ptregs = task_pt_regs(tsk); | |
298 | elf_core_copy_regs(regs, ptregs); | |
299 | return 1; | |
300 | } | |
301 | ||
302 | #if CHIP_HAS_TILE_DMA() | |
303 | ||
304 | /* Allow user processes to access the DMA SPRs */ | |
305 | void grant_dma_mpls(void) | |
306 | { | |
307 | __insn_mtspr(SPR_MPL_DMA_CPL_SET_0, 1); | |
308 | __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_0, 1); | |
309 | } | |
310 | ||
311 | /* Forbid user processes from accessing the DMA SPRs */ | |
312 | void restrict_dma_mpls(void) | |
313 | { | |
314 | __insn_mtspr(SPR_MPL_DMA_CPL_SET_1, 1); | |
315 | __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_1, 1); | |
316 | } | |
317 | ||
318 | /* Pause the DMA engine, then save off its state registers. */ | |
319 | static void save_tile_dma_state(struct tile_dma_state *dma) | |
320 | { | |
321 | unsigned long state = __insn_mfspr(SPR_DMA_USER_STATUS); | |
322 | unsigned long post_suspend_state; | |
323 | ||
324 | /* If we're running, suspend the engine. */ | |
325 | if ((state & DMA_STATUS_MASK) == SPR_DMA_STATUS__RUNNING_MASK) | |
326 | __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__SUSPEND_MASK); | |
327 | ||
328 | /* | |
329 | * Wait for the engine to idle, then save regs. Note that we | |
330 | * want to record the "running" bit from before suspension, | |
331 | * and the "done" bit from after, so that we can properly | |
332 | * distinguish a case where the user suspended the engine from | |
333 | * the case where the kernel suspended as part of the context | |
334 | * swap. | |
335 | */ | |
336 | do { | |
337 | post_suspend_state = __insn_mfspr(SPR_DMA_USER_STATUS); | |
338 | } while (post_suspend_state & SPR_DMA_STATUS__BUSY_MASK); | |
339 | ||
340 | dma->src = __insn_mfspr(SPR_DMA_SRC_ADDR); | |
341 | dma->src_chunk = __insn_mfspr(SPR_DMA_SRC_CHUNK_ADDR); | |
342 | dma->dest = __insn_mfspr(SPR_DMA_DST_ADDR); | |
343 | dma->dest_chunk = __insn_mfspr(SPR_DMA_DST_CHUNK_ADDR); | |
344 | dma->strides = __insn_mfspr(SPR_DMA_STRIDE); | |
345 | dma->chunk_size = __insn_mfspr(SPR_DMA_CHUNK_SIZE); | |
346 | dma->byte = __insn_mfspr(SPR_DMA_BYTE); | |
347 | dma->status = (state & SPR_DMA_STATUS__RUNNING_MASK) | | |
348 | (post_suspend_state & SPR_DMA_STATUS__DONE_MASK); | |
349 | } | |
350 | ||
351 | /* Restart a DMA that was running before we were context-switched out. */ | |
352 | static void restore_tile_dma_state(struct thread_struct *t) | |
353 | { | |
354 | const struct tile_dma_state *dma = &t->tile_dma_state; | |
355 | ||
356 | /* | |
357 | * The only way to restore the done bit is to run a zero | |
358 | * length transaction. | |
359 | */ | |
360 | if ((dma->status & SPR_DMA_STATUS__DONE_MASK) && | |
361 | !(__insn_mfspr(SPR_DMA_USER_STATUS) & SPR_DMA_STATUS__DONE_MASK)) { | |
362 | __insn_mtspr(SPR_DMA_BYTE, 0); | |
363 | __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__REQUEST_MASK); | |
364 | while (__insn_mfspr(SPR_DMA_USER_STATUS) & | |
365 | SPR_DMA_STATUS__BUSY_MASK) | |
366 | ; | |
367 | } | |
368 | ||
369 | __insn_mtspr(SPR_DMA_SRC_ADDR, dma->src); | |
370 | __insn_mtspr(SPR_DMA_SRC_CHUNK_ADDR, dma->src_chunk); | |
371 | __insn_mtspr(SPR_DMA_DST_ADDR, dma->dest); | |
372 | __insn_mtspr(SPR_DMA_DST_CHUNK_ADDR, dma->dest_chunk); | |
373 | __insn_mtspr(SPR_DMA_STRIDE, dma->strides); | |
374 | __insn_mtspr(SPR_DMA_CHUNK_SIZE, dma->chunk_size); | |
375 | __insn_mtspr(SPR_DMA_BYTE, dma->byte); | |
376 | ||
377 | /* | |
378 | * Restart the engine if we were running and not done. | |
379 | * Clear a pending async DMA fault that we were waiting on return | |
380 | * to user space to execute, since we expect the DMA engine | |
381 | * to regenerate those faults for us now. Note that we don't | |
382 | * try to clear the TIF_ASYNC_TLB flag, since it's relatively | |
383 | * harmless if set, and it covers both DMA and the SN processor. | |
384 | */ | |
385 | if ((dma->status & DMA_STATUS_MASK) == SPR_DMA_STATUS__RUNNING_MASK) { | |
386 | t->dma_async_tlb.fault_num = 0; | |
387 | __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__REQUEST_MASK); | |
388 | } | |
389 | } | |
390 | ||
391 | #endif | |
392 | ||
393 | static void save_arch_state(struct thread_struct *t) | |
394 | { | |
395 | #if CHIP_HAS_SPLIT_INTR_MASK() | |
396 | t->interrupt_mask = __insn_mfspr(SPR_INTERRUPT_MASK_0_0) | | |
397 | ((u64)__insn_mfspr(SPR_INTERRUPT_MASK_0_1) << 32); | |
398 | #else | |
399 | t->interrupt_mask = __insn_mfspr(SPR_INTERRUPT_MASK_0); | |
400 | #endif | |
401 | t->ex_context[0] = __insn_mfspr(SPR_EX_CONTEXT_0_0); | |
402 | t->ex_context[1] = __insn_mfspr(SPR_EX_CONTEXT_0_1); | |
403 | t->system_save[0] = __insn_mfspr(SPR_SYSTEM_SAVE_0_0); | |
404 | t->system_save[1] = __insn_mfspr(SPR_SYSTEM_SAVE_0_1); | |
405 | t->system_save[2] = __insn_mfspr(SPR_SYSTEM_SAVE_0_2); | |
406 | t->system_save[3] = __insn_mfspr(SPR_SYSTEM_SAVE_0_3); | |
407 | t->intctrl_0 = __insn_mfspr(SPR_INTCTRL_0_STATUS); | |
408 | #if CHIP_HAS_PROC_STATUS_SPR() | |
409 | t->proc_status = __insn_mfspr(SPR_PROC_STATUS); | |
410 | #endif | |
a802fc68 CM |
411 | #if !CHIP_HAS_FIXED_INTVEC_BASE() |
412 | t->interrupt_vector_base = __insn_mfspr(SPR_INTERRUPT_VECTOR_BASE_0); | |
413 | #endif | |
414 | #if CHIP_HAS_TILE_RTF_HWM() | |
415 | t->tile_rtf_hwm = __insn_mfspr(SPR_TILE_RTF_HWM); | |
416 | #endif | |
417 | #if CHIP_HAS_DSTREAM_PF() | |
418 | t->dstream_pf = __insn_mfspr(SPR_DSTREAM_PF); | |
419 | #endif | |
867e359b CM |
420 | } |
421 | ||
422 | static void restore_arch_state(const struct thread_struct *t) | |
423 | { | |
424 | #if CHIP_HAS_SPLIT_INTR_MASK() | |
425 | __insn_mtspr(SPR_INTERRUPT_MASK_0_0, (u32) t->interrupt_mask); | |
426 | __insn_mtspr(SPR_INTERRUPT_MASK_0_1, t->interrupt_mask >> 32); | |
427 | #else | |
428 | __insn_mtspr(SPR_INTERRUPT_MASK_0, t->interrupt_mask); | |
429 | #endif | |
430 | __insn_mtspr(SPR_EX_CONTEXT_0_0, t->ex_context[0]); | |
431 | __insn_mtspr(SPR_EX_CONTEXT_0_1, t->ex_context[1]); | |
432 | __insn_mtspr(SPR_SYSTEM_SAVE_0_0, t->system_save[0]); | |
433 | __insn_mtspr(SPR_SYSTEM_SAVE_0_1, t->system_save[1]); | |
434 | __insn_mtspr(SPR_SYSTEM_SAVE_0_2, t->system_save[2]); | |
435 | __insn_mtspr(SPR_SYSTEM_SAVE_0_3, t->system_save[3]); | |
436 | __insn_mtspr(SPR_INTCTRL_0_STATUS, t->intctrl_0); | |
437 | #if CHIP_HAS_PROC_STATUS_SPR() | |
438 | __insn_mtspr(SPR_PROC_STATUS, t->proc_status); | |
439 | #endif | |
a802fc68 CM |
440 | #if !CHIP_HAS_FIXED_INTVEC_BASE() |
441 | __insn_mtspr(SPR_INTERRUPT_VECTOR_BASE_0, t->interrupt_vector_base); | |
442 | #endif | |
867e359b | 443 | #if CHIP_HAS_TILE_RTF_HWM() |
a802fc68 CM |
444 | __insn_mtspr(SPR_TILE_RTF_HWM, t->tile_rtf_hwm); |
445 | #endif | |
446 | #if CHIP_HAS_DSTREAM_PF() | |
447 | __insn_mtspr(SPR_DSTREAM_PF, t->dstream_pf); | |
867e359b CM |
448 | #endif |
449 | } | |
450 | ||
451 | ||
452 | void _prepare_arch_switch(struct task_struct *next) | |
453 | { | |
454 | #if CHIP_HAS_SN_PROC() | |
455 | int snctl; | |
456 | #endif | |
457 | #if CHIP_HAS_TILE_DMA() | |
458 | struct tile_dma_state *dma = ¤t->thread.tile_dma_state; | |
459 | if (dma->enabled) | |
460 | save_tile_dma_state(dma); | |
461 | #endif | |
462 | #if CHIP_HAS_SN_PROC() | |
463 | /* | |
464 | * Suspend the static network processor if it was running. | |
465 | * We do not suspend the fabric itself, just like we don't | |
466 | * try to suspend the UDN. | |
467 | */ | |
468 | snctl = __insn_mfspr(SPR_SNCTL); | |
469 | current->thread.sn_proc_running = | |
470 | (snctl & SPR_SNCTL__FRZPROC_MASK) == 0; | |
471 | if (current->thread.sn_proc_running) | |
472 | __insn_mtspr(SPR_SNCTL, snctl | SPR_SNCTL__FRZPROC_MASK); | |
473 | #endif | |
474 | } | |
475 | ||
476 | ||
867e359b CM |
477 | struct task_struct *__sched _switch_to(struct task_struct *prev, |
478 | struct task_struct *next) | |
479 | { | |
480 | /* DMA state is already saved; save off other arch state. */ | |
481 | save_arch_state(&prev->thread); | |
482 | ||
483 | #if CHIP_HAS_TILE_DMA() | |
484 | /* | |
485 | * Restore DMA in new task if desired. | |
486 | * Note that it is only safe to restart here since interrupts | |
487 | * are disabled, so we can't take any DMATLB miss or access | |
488 | * interrupts before we have finished switching stacks. | |
489 | */ | |
490 | if (next->thread.tile_dma_state.enabled) { | |
491 | restore_tile_dma_state(&next->thread); | |
492 | grant_dma_mpls(); | |
493 | } else { | |
494 | restrict_dma_mpls(); | |
495 | } | |
496 | #endif | |
497 | ||
498 | /* Restore other arch state. */ | |
499 | restore_arch_state(&next->thread); | |
500 | ||
501 | #if CHIP_HAS_SN_PROC() | |
502 | /* | |
503 | * Restart static network processor in the new process | |
504 | * if it was running before. | |
505 | */ | |
506 | if (next->thread.sn_proc_running) { | |
507 | int snctl = __insn_mfspr(SPR_SNCTL); | |
508 | __insn_mtspr(SPR_SNCTL, snctl & ~SPR_SNCTL__FRZPROC_MASK); | |
509 | } | |
510 | #endif | |
511 | ||
0707ad30 CM |
512 | #ifdef CONFIG_HARDWALL |
513 | /* Enable or disable access to the network registers appropriately. */ | |
514 | if (prev->thread.hardwall != NULL) { | |
515 | if (next->thread.hardwall == NULL) | |
516 | restrict_network_mpls(); | |
517 | } else if (next->thread.hardwall != NULL) { | |
518 | grant_network_mpls(); | |
519 | } | |
520 | #endif | |
867e359b CM |
521 | |
522 | /* | |
523 | * Switch kernel SP, PC, and callee-saved registers. | |
524 | * In the context of the new task, return the old task pointer | |
525 | * (i.e. the task that actually called __switch_to). | |
526 | * Pass the value to use for SYSTEM_SAVE_1_0 when we reset our sp. | |
527 | */ | |
528 | return __switch_to(prev, next, next_current_ksp0(next)); | |
529 | } | |
530 | ||
0707ad30 | 531 | long _sys_fork(struct pt_regs *regs) |
867e359b CM |
532 | { |
533 | return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL); | |
534 | } | |
535 | ||
0707ad30 CM |
536 | long _sys_clone(unsigned long clone_flags, unsigned long newsp, |
537 | void __user *parent_tidptr, void __user *child_tidptr, | |
538 | struct pt_regs *regs) | |
867e359b CM |
539 | { |
540 | if (!newsp) | |
541 | newsp = regs->sp; | |
542 | return do_fork(clone_flags, newsp, regs, 0, | |
543 | parent_tidptr, child_tidptr); | |
544 | } | |
545 | ||
0707ad30 | 546 | long _sys_vfork(struct pt_regs *regs) |
867e359b CM |
547 | { |
548 | return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, | |
549 | regs, 0, NULL, NULL); | |
550 | } | |
551 | ||
552 | /* | |
553 | * sys_execve() executes a new program. | |
554 | */ | |
d7627467 DH |
555 | long _sys_execve(const char __user *path, |
556 | const char __user *const __user *argv, | |
557 | const char __user *const __user *envp, struct pt_regs *regs) | |
867e359b | 558 | { |
0707ad30 | 559 | long error; |
867e359b CM |
560 | char *filename; |
561 | ||
562 | filename = getname(path); | |
563 | error = PTR_ERR(filename); | |
564 | if (IS_ERR(filename)) | |
565 | goto out; | |
566 | error = do_execve(filename, argv, envp, regs); | |
567 | putname(filename); | |
568 | out: | |
569 | return error; | |
570 | } | |
571 | ||
572 | #ifdef CONFIG_COMPAT | |
e6e6c46d CM |
573 | long _compat_sys_execve(const char __user *path, |
574 | const compat_uptr_t __user *argv, | |
575 | const compat_uptr_t __user *envp, struct pt_regs *regs) | |
867e359b | 576 | { |
0707ad30 | 577 | long error; |
867e359b CM |
578 | char *filename; |
579 | ||
580 | filename = getname(path); | |
581 | error = PTR_ERR(filename); | |
582 | if (IS_ERR(filename)) | |
583 | goto out; | |
584 | error = compat_do_execve(filename, argv, envp, regs); | |
585 | putname(filename); | |
586 | out: | |
587 | return error; | |
588 | } | |
589 | #endif | |
590 | ||
591 | unsigned long get_wchan(struct task_struct *p) | |
592 | { | |
593 | struct KBacktraceIterator kbt; | |
594 | ||
595 | if (!p || p == current || p->state == TASK_RUNNING) | |
596 | return 0; | |
597 | ||
598 | for (KBacktraceIterator_init(&kbt, p, NULL); | |
599 | !KBacktraceIterator_end(&kbt); | |
600 | KBacktraceIterator_next(&kbt)) { | |
601 | if (!in_sched_functions(kbt.it.pc)) | |
602 | return kbt.it.pc; | |
603 | } | |
604 | ||
605 | return 0; | |
606 | } | |
607 | ||
608 | /* | |
609 | * We pass in lr as zero (cleared in kernel_thread) and the caller | |
610 | * part of the backtrace ABI on the stack also zeroed (in copy_thread) | |
611 | * so that backtraces will stop with this function. | |
612 | * Note that we don't use r0, since copy_thread() clears it. | |
613 | */ | |
614 | static void start_kernel_thread(int dummy, int (*fn)(int), int arg) | |
615 | { | |
616 | do_exit(fn(arg)); | |
617 | } | |
618 | ||
619 | /* | |
620 | * Create a kernel thread | |
621 | */ | |
622 | int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) | |
623 | { | |
624 | struct pt_regs regs; | |
625 | ||
626 | memset(®s, 0, sizeof(regs)); | |
627 | regs.ex1 = PL_ICS_EX1(KERNEL_PL, 0); /* run at kernel PL, no ICS */ | |
628 | regs.pc = (long) start_kernel_thread; | |
629 | regs.flags = PT_FLAGS_CALLER_SAVES; /* need to restore r1 and r2 */ | |
630 | regs.regs[1] = (long) fn; /* function pointer */ | |
631 | regs.regs[2] = (long) arg; /* parameter register */ | |
632 | ||
633 | /* Ok, create the new process.. */ | |
634 | return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, | |
635 | 0, NULL, NULL); | |
636 | } | |
637 | EXPORT_SYMBOL(kernel_thread); | |
638 | ||
639 | /* Flush thread state. */ | |
640 | void flush_thread(void) | |
641 | { | |
642 | /* Nothing */ | |
643 | } | |
644 | ||
645 | /* | |
646 | * Free current thread data structures etc.. | |
647 | */ | |
648 | void exit_thread(void) | |
649 | { | |
650 | /* Nothing */ | |
651 | } | |
652 | ||
867e359b CM |
653 | void show_regs(struct pt_regs *regs) |
654 | { | |
655 | struct task_struct *tsk = validate_current(); | |
0707ad30 CM |
656 | int i; |
657 | ||
658 | pr_err("\n"); | |
659 | pr_err(" Pid: %d, comm: %20s, CPU: %d\n", | |
867e359b | 660 | tsk->pid, tsk->comm, smp_processor_id()); |
0707ad30 CM |
661 | #ifdef __tilegx__ |
662 | for (i = 0; i < 51; i += 3) | |
663 | pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT" r%-2d: "REGFMT"\n", | |
664 | i, regs->regs[i], i+1, regs->regs[i+1], | |
665 | i+2, regs->regs[i+2]); | |
666 | pr_err(" r51: "REGFMT" r52: "REGFMT" tp : "REGFMT"\n", | |
667 | regs->regs[51], regs->regs[52], regs->tp); | |
668 | pr_err(" sp : "REGFMT" lr : "REGFMT"\n", regs->sp, regs->lr); | |
669 | #else | |
7040dea4 | 670 | for (i = 0; i < 52; i += 4) |
0707ad30 CM |
671 | pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT |
672 | " r%-2d: "REGFMT" r%-2d: "REGFMT"\n", | |
673 | i, regs->regs[i], i+1, regs->regs[i+1], | |
674 | i+2, regs->regs[i+2], i+3, regs->regs[i+3]); | |
675 | pr_err(" r52: "REGFMT" tp : "REGFMT" sp : "REGFMT" lr : "REGFMT"\n", | |
676 | regs->regs[52], regs->tp, regs->sp, regs->lr); | |
677 | #endif | |
678 | pr_err(" pc : "REGFMT" ex1: %ld faultnum: %ld\n", | |
867e359b CM |
679 | regs->pc, regs->ex1, regs->faultnum); |
680 | ||
681 | dump_stack_regs(regs); | |
682 | } |