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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> |
313ce674 CM |
28 | #include <linux/tracehook.h> |
29 | #include <linux/signal.h> | |
867e359b CM |
30 | #include <asm/system.h> |
31 | #include <asm/stack.h> | |
32 | #include <asm/homecache.h> | |
0707ad30 | 33 | #include <asm/syscalls.h> |
313ce674 | 34 | #include <asm/traps.h> |
0707ad30 CM |
35 | #ifdef CONFIG_HARDWALL |
36 | #include <asm/hardwall.h> | |
37 | #endif | |
867e359b CM |
38 | #include <arch/chip.h> |
39 | #include <arch/abi.h> | |
40 | ||
41 | ||
42 | /* | |
43 | * Use the (x86) "idle=poll" option to prefer low latency when leaving the | |
44 | * idle loop over low power while in the idle loop, e.g. if we have | |
45 | * one thread per core and we want to get threads out of futex waits fast. | |
46 | */ | |
47 | static int no_idle_nap; | |
48 | static int __init idle_setup(char *str) | |
49 | { | |
50 | if (!str) | |
51 | return -EINVAL; | |
52 | ||
53 | if (!strcmp(str, "poll")) { | |
0707ad30 | 54 | pr_info("using polling idle threads.\n"); |
867e359b CM |
55 | no_idle_nap = 1; |
56 | } else if (!strcmp(str, "halt")) | |
57 | no_idle_nap = 0; | |
58 | else | |
59 | return -1; | |
60 | ||
61 | return 0; | |
62 | } | |
63 | early_param("idle", idle_setup); | |
64 | ||
65 | /* | |
66 | * The idle thread. There's no useful work to be | |
67 | * done, so just try to conserve power and have a | |
68 | * low exit latency (ie sit in a loop waiting for | |
69 | * somebody to say that they'd like to reschedule) | |
70 | */ | |
71 | void cpu_idle(void) | |
72 | { | |
867e359b CM |
73 | int cpu = smp_processor_id(); |
74 | ||
75 | ||
76 | current_thread_info()->status |= TS_POLLING; | |
77 | ||
78 | if (no_idle_nap) { | |
79 | while (1) { | |
80 | while (!need_resched()) | |
81 | cpu_relax(); | |
82 | schedule(); | |
83 | } | |
84 | } | |
85 | ||
86 | /* endless idle loop with no priority at all */ | |
87 | while (1) { | |
88 | tick_nohz_stop_sched_tick(1); | |
89 | while (!need_resched()) { | |
90 | if (cpu_is_offline(cpu)) | |
91 | BUG(); /* no HOTPLUG_CPU */ | |
92 | ||
93 | local_irq_disable(); | |
94 | __get_cpu_var(irq_stat).idle_timestamp = jiffies; | |
95 | current_thread_info()->status &= ~TS_POLLING; | |
96 | /* | |
97 | * TS_POLLING-cleared state must be visible before we | |
98 | * test NEED_RESCHED: | |
99 | */ | |
100 | smp_mb(); | |
101 | ||
102 | if (!need_resched()) | |
103 | _cpu_idle(); | |
104 | else | |
105 | local_irq_enable(); | |
106 | current_thread_info()->status |= TS_POLLING; | |
107 | } | |
108 | tick_nohz_restart_sched_tick(); | |
109 | preempt_enable_no_resched(); | |
110 | schedule(); | |
111 | preempt_disable(); | |
112 | } | |
113 | } | |
114 | ||
b6a84016 | 115 | struct thread_info *alloc_thread_info_node(struct task_struct *task, int node) |
867e359b CM |
116 | { |
117 | struct page *page; | |
0707ad30 | 118 | gfp_t flags = GFP_KERNEL; |
867e359b CM |
119 | |
120 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
121 | flags |= __GFP_ZERO; | |
122 | #endif | |
123 | ||
b6a84016 | 124 | page = alloc_pages_node(node, flags, THREAD_SIZE_ORDER); |
867e359b | 125 | if (!page) |
0707ad30 | 126 | return NULL; |
867e359b CM |
127 | |
128 | return (struct thread_info *)page_address(page); | |
129 | } | |
130 | ||
131 | /* | |
132 | * Free a thread_info node, and all of its derivative | |
133 | * data structures. | |
134 | */ | |
135 | void free_thread_info(struct thread_info *info) | |
136 | { | |
137 | struct single_step_state *step_state = info->step_state; | |
138 | ||
0707ad30 CM |
139 | #ifdef CONFIG_HARDWALL |
140 | /* | |
141 | * We free a thread_info from the context of the task that has | |
142 | * been scheduled next, so the original task is already dead. | |
143 | * Calling deactivate here just frees up the data structures. | |
144 | * If the task we're freeing held the last reference to a | |
145 | * hardwall fd, it would have been released prior to this point | |
146 | * anyway via exit_files(), and "hardwall" would be NULL by now. | |
147 | */ | |
148 | if (info->task->thread.hardwall) | |
149 | hardwall_deactivate(info->task); | |
150 | #endif | |
867e359b CM |
151 | |
152 | if (step_state) { | |
153 | ||
154 | /* | |
155 | * FIXME: we don't munmap step_state->buffer | |
156 | * because the mm_struct for this process (info->task->mm) | |
157 | * has already been zeroed in exit_mm(). Keeping a | |
158 | * reference to it here seems like a bad move, so this | |
159 | * means we can't munmap() the buffer, and therefore if we | |
160 | * ptrace multiple threads in a process, we will slowly | |
161 | * leak user memory. (Note that as soon as the last | |
162 | * thread in a process dies, we will reclaim all user | |
163 | * memory including single-step buffers in the usual way.) | |
164 | * We should either assign a kernel VA to this buffer | |
165 | * somehow, or we should associate the buffer(s) with the | |
166 | * mm itself so we can clean them up that way. | |
167 | */ | |
168 | kfree(step_state); | |
169 | } | |
170 | ||
76c567fb | 171 | free_pages((unsigned long)info, THREAD_SIZE_ORDER); |
867e359b CM |
172 | } |
173 | ||
174 | static void save_arch_state(struct thread_struct *t); | |
175 | ||
867e359b CM |
176 | int copy_thread(unsigned long clone_flags, unsigned long sp, |
177 | unsigned long stack_size, | |
178 | struct task_struct *p, struct pt_regs *regs) | |
179 | { | |
180 | struct pt_regs *childregs; | |
181 | unsigned long ksp; | |
182 | ||
183 | /* | |
184 | * When creating a new kernel thread we pass sp as zero. | |
185 | * Assign it to a reasonable value now that we have the stack. | |
186 | */ | |
187 | if (sp == 0 && regs->ex1 == PL_ICS_EX1(KERNEL_PL, 0)) | |
188 | sp = KSTK_TOP(p); | |
189 | ||
190 | /* | |
191 | * Do not clone step state from the parent; each thread | |
192 | * must make its own lazily. | |
193 | */ | |
194 | task_thread_info(p)->step_state = NULL; | |
195 | ||
196 | /* | |
197 | * Start new thread in ret_from_fork so it schedules properly | |
198 | * and then return from interrupt like the parent. | |
199 | */ | |
200 | p->thread.pc = (unsigned long) ret_from_fork; | |
201 | ||
202 | /* Save user stack top pointer so we can ID the stack vm area later. */ | |
203 | p->thread.usp0 = sp; | |
204 | ||
205 | /* Record the pid of the process that created this one. */ | |
206 | p->thread.creator_pid = current->pid; | |
207 | ||
208 | /* | |
209 | * Copy the registers onto the kernel stack so the | |
210 | * return-from-interrupt code will reload it into registers. | |
211 | */ | |
212 | childregs = task_pt_regs(p); | |
213 | *childregs = *regs; | |
214 | childregs->regs[0] = 0; /* return value is zero */ | |
215 | childregs->sp = sp; /* override with new user stack pointer */ | |
216 | ||
bc4cf2bb CM |
217 | /* |
218 | * If CLONE_SETTLS is set, set "tp" in the new task to "r4", | |
219 | * which is passed in as arg #5 to sys_clone(). | |
220 | */ | |
221 | if (clone_flags & CLONE_SETTLS) | |
222 | childregs->tp = regs->regs[4]; | |
223 | ||
867e359b CM |
224 | /* |
225 | * Copy the callee-saved registers from the passed pt_regs struct | |
226 | * into the context-switch callee-saved registers area. | |
d6f0f22c CM |
227 | * This way when we start the interrupt-return sequence, the |
228 | * callee-save registers will be correctly in registers, which | |
229 | * is how we assume the compiler leaves them as we start doing | |
230 | * the normal return-from-interrupt path after calling C code. | |
867e359b CM |
231 | * Zero out the C ABI save area to mark the top of the stack. |
232 | */ | |
233 | ksp = (unsigned long) childregs; | |
234 | ksp -= C_ABI_SAVE_AREA_SIZE; /* interrupt-entry save area */ | |
235 | ((long *)ksp)[0] = ((long *)ksp)[1] = 0; | |
236 | ksp -= CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long); | |
237 | memcpy((void *)ksp, ®s->regs[CALLEE_SAVED_FIRST_REG], | |
238 | CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long)); | |
239 | ksp -= C_ABI_SAVE_AREA_SIZE; /* __switch_to() save area */ | |
240 | ((long *)ksp)[0] = ((long *)ksp)[1] = 0; | |
241 | p->thread.ksp = ksp; | |
242 | ||
243 | #if CHIP_HAS_TILE_DMA() | |
244 | /* | |
245 | * No DMA in the new thread. We model this on the fact that | |
246 | * fork() clears the pending signals, alarms, and aio for the child. | |
247 | */ | |
248 | memset(&p->thread.tile_dma_state, 0, sizeof(struct tile_dma_state)); | |
249 | memset(&p->thread.dma_async_tlb, 0, sizeof(struct async_tlb)); | |
250 | #endif | |
251 | ||
252 | #if CHIP_HAS_SN_PROC() | |
253 | /* Likewise, the new thread is not running static processor code. */ | |
254 | p->thread.sn_proc_running = 0; | |
255 | memset(&p->thread.sn_async_tlb, 0, sizeof(struct async_tlb)); | |
256 | #endif | |
257 | ||
258 | #if CHIP_HAS_PROC_STATUS_SPR() | |
259 | /* New thread has its miscellaneous processor state bits clear. */ | |
260 | p->thread.proc_status = 0; | |
261 | #endif | |
262 | ||
0707ad30 CM |
263 | #ifdef CONFIG_HARDWALL |
264 | /* New thread does not own any networks. */ | |
265 | p->thread.hardwall = NULL; | |
266 | #endif | |
867e359b CM |
267 | |
268 | ||
269 | /* | |
270 | * Start the new thread with the current architecture state | |
271 | * (user interrupt masks, etc.). | |
272 | */ | |
273 | save_arch_state(&p->thread); | |
274 | ||
275 | return 0; | |
276 | } | |
277 | ||
278 | /* | |
279 | * Return "current" if it looks plausible, or else a pointer to a dummy. | |
280 | * This can be helpful if we are just trying to emit a clean panic. | |
281 | */ | |
282 | struct task_struct *validate_current(void) | |
283 | { | |
284 | static struct task_struct corrupt = { .comm = "<corrupt>" }; | |
285 | struct task_struct *tsk = current; | |
286 | if (unlikely((unsigned long)tsk < PAGE_OFFSET || | |
287 | (void *)tsk > high_memory || | |
288 | ((unsigned long)tsk & (__alignof__(*tsk) - 1)) != 0)) { | |
0707ad30 | 289 | pr_err("Corrupt 'current' %p (sp %#lx)\n", tsk, stack_pointer); |
867e359b CM |
290 | tsk = &corrupt; |
291 | } | |
292 | return tsk; | |
293 | } | |
294 | ||
295 | /* Take and return the pointer to the previous task, for schedule_tail(). */ | |
296 | struct task_struct *sim_notify_fork(struct task_struct *prev) | |
297 | { | |
298 | struct task_struct *tsk = current; | |
299 | __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_FORK_PARENT | | |
300 | (tsk->thread.creator_pid << _SIM_CONTROL_OPERATOR_BITS)); | |
301 | __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_FORK | | |
302 | (tsk->pid << _SIM_CONTROL_OPERATOR_BITS)); | |
303 | return prev; | |
304 | } | |
305 | ||
306 | int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs) | |
307 | { | |
308 | struct pt_regs *ptregs = task_pt_regs(tsk); | |
309 | elf_core_copy_regs(regs, ptregs); | |
310 | return 1; | |
311 | } | |
312 | ||
313 | #if CHIP_HAS_TILE_DMA() | |
314 | ||
315 | /* Allow user processes to access the DMA SPRs */ | |
316 | void grant_dma_mpls(void) | |
317 | { | |
a78c942d CM |
318 | #if CONFIG_KERNEL_PL == 2 |
319 | __insn_mtspr(SPR_MPL_DMA_CPL_SET_1, 1); | |
320 | __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_1, 1); | |
321 | #else | |
867e359b CM |
322 | __insn_mtspr(SPR_MPL_DMA_CPL_SET_0, 1); |
323 | __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_0, 1); | |
a78c942d | 324 | #endif |
867e359b CM |
325 | } |
326 | ||
327 | /* Forbid user processes from accessing the DMA SPRs */ | |
328 | void restrict_dma_mpls(void) | |
329 | { | |
a78c942d CM |
330 | #if CONFIG_KERNEL_PL == 2 |
331 | __insn_mtspr(SPR_MPL_DMA_CPL_SET_2, 1); | |
332 | __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_2, 1); | |
333 | #else | |
867e359b CM |
334 | __insn_mtspr(SPR_MPL_DMA_CPL_SET_1, 1); |
335 | __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_1, 1); | |
a78c942d | 336 | #endif |
867e359b CM |
337 | } |
338 | ||
339 | /* Pause the DMA engine, then save off its state registers. */ | |
340 | static void save_tile_dma_state(struct tile_dma_state *dma) | |
341 | { | |
342 | unsigned long state = __insn_mfspr(SPR_DMA_USER_STATUS); | |
343 | unsigned long post_suspend_state; | |
344 | ||
345 | /* If we're running, suspend the engine. */ | |
346 | if ((state & DMA_STATUS_MASK) == SPR_DMA_STATUS__RUNNING_MASK) | |
347 | __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__SUSPEND_MASK); | |
348 | ||
349 | /* | |
350 | * Wait for the engine to idle, then save regs. Note that we | |
351 | * want to record the "running" bit from before suspension, | |
352 | * and the "done" bit from after, so that we can properly | |
353 | * distinguish a case where the user suspended the engine from | |
354 | * the case where the kernel suspended as part of the context | |
355 | * swap. | |
356 | */ | |
357 | do { | |
358 | post_suspend_state = __insn_mfspr(SPR_DMA_USER_STATUS); | |
359 | } while (post_suspend_state & SPR_DMA_STATUS__BUSY_MASK); | |
360 | ||
361 | dma->src = __insn_mfspr(SPR_DMA_SRC_ADDR); | |
362 | dma->src_chunk = __insn_mfspr(SPR_DMA_SRC_CHUNK_ADDR); | |
363 | dma->dest = __insn_mfspr(SPR_DMA_DST_ADDR); | |
364 | dma->dest_chunk = __insn_mfspr(SPR_DMA_DST_CHUNK_ADDR); | |
365 | dma->strides = __insn_mfspr(SPR_DMA_STRIDE); | |
366 | dma->chunk_size = __insn_mfspr(SPR_DMA_CHUNK_SIZE); | |
367 | dma->byte = __insn_mfspr(SPR_DMA_BYTE); | |
368 | dma->status = (state & SPR_DMA_STATUS__RUNNING_MASK) | | |
369 | (post_suspend_state & SPR_DMA_STATUS__DONE_MASK); | |
370 | } | |
371 | ||
372 | /* Restart a DMA that was running before we were context-switched out. */ | |
373 | static void restore_tile_dma_state(struct thread_struct *t) | |
374 | { | |
375 | const struct tile_dma_state *dma = &t->tile_dma_state; | |
376 | ||
377 | /* | |
378 | * The only way to restore the done bit is to run a zero | |
379 | * length transaction. | |
380 | */ | |
381 | if ((dma->status & SPR_DMA_STATUS__DONE_MASK) && | |
382 | !(__insn_mfspr(SPR_DMA_USER_STATUS) & SPR_DMA_STATUS__DONE_MASK)) { | |
383 | __insn_mtspr(SPR_DMA_BYTE, 0); | |
384 | __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__REQUEST_MASK); | |
385 | while (__insn_mfspr(SPR_DMA_USER_STATUS) & | |
386 | SPR_DMA_STATUS__BUSY_MASK) | |
387 | ; | |
388 | } | |
389 | ||
390 | __insn_mtspr(SPR_DMA_SRC_ADDR, dma->src); | |
391 | __insn_mtspr(SPR_DMA_SRC_CHUNK_ADDR, dma->src_chunk); | |
392 | __insn_mtspr(SPR_DMA_DST_ADDR, dma->dest); | |
393 | __insn_mtspr(SPR_DMA_DST_CHUNK_ADDR, dma->dest_chunk); | |
394 | __insn_mtspr(SPR_DMA_STRIDE, dma->strides); | |
395 | __insn_mtspr(SPR_DMA_CHUNK_SIZE, dma->chunk_size); | |
396 | __insn_mtspr(SPR_DMA_BYTE, dma->byte); | |
397 | ||
398 | /* | |
399 | * Restart the engine if we were running and not done. | |
400 | * Clear a pending async DMA fault that we were waiting on return | |
401 | * to user space to execute, since we expect the DMA engine | |
402 | * to regenerate those faults for us now. Note that we don't | |
403 | * try to clear the TIF_ASYNC_TLB flag, since it's relatively | |
404 | * harmless if set, and it covers both DMA and the SN processor. | |
405 | */ | |
406 | if ((dma->status & DMA_STATUS_MASK) == SPR_DMA_STATUS__RUNNING_MASK) { | |
407 | t->dma_async_tlb.fault_num = 0; | |
408 | __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__REQUEST_MASK); | |
409 | } | |
410 | } | |
411 | ||
412 | #endif | |
413 | ||
414 | static void save_arch_state(struct thread_struct *t) | |
415 | { | |
416 | #if CHIP_HAS_SPLIT_INTR_MASK() | |
417 | t->interrupt_mask = __insn_mfspr(SPR_INTERRUPT_MASK_0_0) | | |
418 | ((u64)__insn_mfspr(SPR_INTERRUPT_MASK_0_1) << 32); | |
419 | #else | |
420 | t->interrupt_mask = __insn_mfspr(SPR_INTERRUPT_MASK_0); | |
421 | #endif | |
422 | t->ex_context[0] = __insn_mfspr(SPR_EX_CONTEXT_0_0); | |
423 | t->ex_context[1] = __insn_mfspr(SPR_EX_CONTEXT_0_1); | |
424 | t->system_save[0] = __insn_mfspr(SPR_SYSTEM_SAVE_0_0); | |
425 | t->system_save[1] = __insn_mfspr(SPR_SYSTEM_SAVE_0_1); | |
426 | t->system_save[2] = __insn_mfspr(SPR_SYSTEM_SAVE_0_2); | |
427 | t->system_save[3] = __insn_mfspr(SPR_SYSTEM_SAVE_0_3); | |
428 | t->intctrl_0 = __insn_mfspr(SPR_INTCTRL_0_STATUS); | |
429 | #if CHIP_HAS_PROC_STATUS_SPR() | |
430 | t->proc_status = __insn_mfspr(SPR_PROC_STATUS); | |
431 | #endif | |
a802fc68 CM |
432 | #if !CHIP_HAS_FIXED_INTVEC_BASE() |
433 | t->interrupt_vector_base = __insn_mfspr(SPR_INTERRUPT_VECTOR_BASE_0); | |
434 | #endif | |
435 | #if CHIP_HAS_TILE_RTF_HWM() | |
436 | t->tile_rtf_hwm = __insn_mfspr(SPR_TILE_RTF_HWM); | |
437 | #endif | |
438 | #if CHIP_HAS_DSTREAM_PF() | |
439 | t->dstream_pf = __insn_mfspr(SPR_DSTREAM_PF); | |
440 | #endif | |
867e359b CM |
441 | } |
442 | ||
443 | static void restore_arch_state(const struct thread_struct *t) | |
444 | { | |
445 | #if CHIP_HAS_SPLIT_INTR_MASK() | |
446 | __insn_mtspr(SPR_INTERRUPT_MASK_0_0, (u32) t->interrupt_mask); | |
447 | __insn_mtspr(SPR_INTERRUPT_MASK_0_1, t->interrupt_mask >> 32); | |
448 | #else | |
449 | __insn_mtspr(SPR_INTERRUPT_MASK_0, t->interrupt_mask); | |
450 | #endif | |
451 | __insn_mtspr(SPR_EX_CONTEXT_0_0, t->ex_context[0]); | |
452 | __insn_mtspr(SPR_EX_CONTEXT_0_1, t->ex_context[1]); | |
453 | __insn_mtspr(SPR_SYSTEM_SAVE_0_0, t->system_save[0]); | |
454 | __insn_mtspr(SPR_SYSTEM_SAVE_0_1, t->system_save[1]); | |
455 | __insn_mtspr(SPR_SYSTEM_SAVE_0_2, t->system_save[2]); | |
456 | __insn_mtspr(SPR_SYSTEM_SAVE_0_3, t->system_save[3]); | |
457 | __insn_mtspr(SPR_INTCTRL_0_STATUS, t->intctrl_0); | |
458 | #if CHIP_HAS_PROC_STATUS_SPR() | |
459 | __insn_mtspr(SPR_PROC_STATUS, t->proc_status); | |
460 | #endif | |
a802fc68 CM |
461 | #if !CHIP_HAS_FIXED_INTVEC_BASE() |
462 | __insn_mtspr(SPR_INTERRUPT_VECTOR_BASE_0, t->interrupt_vector_base); | |
463 | #endif | |
867e359b | 464 | #if CHIP_HAS_TILE_RTF_HWM() |
a802fc68 CM |
465 | __insn_mtspr(SPR_TILE_RTF_HWM, t->tile_rtf_hwm); |
466 | #endif | |
467 | #if CHIP_HAS_DSTREAM_PF() | |
468 | __insn_mtspr(SPR_DSTREAM_PF, t->dstream_pf); | |
867e359b CM |
469 | #endif |
470 | } | |
471 | ||
472 | ||
473 | void _prepare_arch_switch(struct task_struct *next) | |
474 | { | |
475 | #if CHIP_HAS_SN_PROC() | |
476 | int snctl; | |
477 | #endif | |
478 | #if CHIP_HAS_TILE_DMA() | |
479 | struct tile_dma_state *dma = ¤t->thread.tile_dma_state; | |
480 | if (dma->enabled) | |
481 | save_tile_dma_state(dma); | |
482 | #endif | |
483 | #if CHIP_HAS_SN_PROC() | |
484 | /* | |
485 | * Suspend the static network processor if it was running. | |
486 | * We do not suspend the fabric itself, just like we don't | |
487 | * try to suspend the UDN. | |
488 | */ | |
489 | snctl = __insn_mfspr(SPR_SNCTL); | |
490 | current->thread.sn_proc_running = | |
491 | (snctl & SPR_SNCTL__FRZPROC_MASK) == 0; | |
492 | if (current->thread.sn_proc_running) | |
493 | __insn_mtspr(SPR_SNCTL, snctl | SPR_SNCTL__FRZPROC_MASK); | |
494 | #endif | |
495 | } | |
496 | ||
497 | ||
867e359b CM |
498 | struct task_struct *__sched _switch_to(struct task_struct *prev, |
499 | struct task_struct *next) | |
500 | { | |
501 | /* DMA state is already saved; save off other arch state. */ | |
502 | save_arch_state(&prev->thread); | |
503 | ||
504 | #if CHIP_HAS_TILE_DMA() | |
505 | /* | |
506 | * Restore DMA in new task if desired. | |
507 | * Note that it is only safe to restart here since interrupts | |
508 | * are disabled, so we can't take any DMATLB miss or access | |
509 | * interrupts before we have finished switching stacks. | |
510 | */ | |
511 | if (next->thread.tile_dma_state.enabled) { | |
512 | restore_tile_dma_state(&next->thread); | |
513 | grant_dma_mpls(); | |
514 | } else { | |
515 | restrict_dma_mpls(); | |
516 | } | |
517 | #endif | |
518 | ||
519 | /* Restore other arch state. */ | |
520 | restore_arch_state(&next->thread); | |
521 | ||
522 | #if CHIP_HAS_SN_PROC() | |
523 | /* | |
524 | * Restart static network processor in the new process | |
525 | * if it was running before. | |
526 | */ | |
527 | if (next->thread.sn_proc_running) { | |
528 | int snctl = __insn_mfspr(SPR_SNCTL); | |
529 | __insn_mtspr(SPR_SNCTL, snctl & ~SPR_SNCTL__FRZPROC_MASK); | |
530 | } | |
531 | #endif | |
532 | ||
0707ad30 CM |
533 | #ifdef CONFIG_HARDWALL |
534 | /* Enable or disable access to the network registers appropriately. */ | |
535 | if (prev->thread.hardwall != NULL) { | |
536 | if (next->thread.hardwall == NULL) | |
537 | restrict_network_mpls(); | |
538 | } else if (next->thread.hardwall != NULL) { | |
539 | grant_network_mpls(); | |
540 | } | |
541 | #endif | |
867e359b CM |
542 | |
543 | /* | |
544 | * Switch kernel SP, PC, and callee-saved registers. | |
545 | * In the context of the new task, return the old task pointer | |
546 | * (i.e. the task that actually called __switch_to). | |
a78c942d | 547 | * Pass the value to use for SYSTEM_SAVE_K_0 when we reset our sp. |
867e359b CM |
548 | */ |
549 | return __switch_to(prev, next, next_current_ksp0(next)); | |
550 | } | |
551 | ||
313ce674 CM |
552 | /* |
553 | * This routine is called on return from interrupt if any of the | |
554 | * TIF_WORK_MASK flags are set in thread_info->flags. It is | |
555 | * entered with interrupts disabled so we don't miss an event | |
556 | * that modified the thread_info flags. If any flag is set, we | |
557 | * handle it and return, and the calling assembly code will | |
558 | * re-disable interrupts, reload the thread flags, and call back | |
559 | * if more flags need to be handled. | |
560 | * | |
561 | * We return whether we need to check the thread_info flags again | |
562 | * or not. Note that we don't clear TIF_SINGLESTEP here, so it's | |
563 | * important that it be tested last, and then claim that we don't | |
564 | * need to recheck the flags. | |
565 | */ | |
566 | int do_work_pending(struct pt_regs *regs, u32 thread_info_flags) | |
567 | { | |
568 | if (thread_info_flags & _TIF_NEED_RESCHED) { | |
569 | schedule(); | |
570 | return 1; | |
571 | } | |
572 | #if CHIP_HAS_TILE_DMA() || CHIP_HAS_SN_PROC() | |
573 | if (thread_info_flags & _TIF_ASYNC_TLB) { | |
574 | do_async_page_fault(regs); | |
575 | return 1; | |
576 | } | |
577 | #endif | |
578 | if (thread_info_flags & _TIF_SIGPENDING) { | |
579 | do_signal(regs); | |
580 | return 1; | |
581 | } | |
582 | if (thread_info_flags & _TIF_NOTIFY_RESUME) { | |
583 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
584 | tracehook_notify_resume(regs); | |
585 | if (current->replacement_session_keyring) | |
586 | key_replace_session_keyring(); | |
587 | return 1; | |
588 | } | |
589 | if (thread_info_flags & _TIF_SINGLESTEP) { | |
590 | if ((regs->ex1 & SPR_EX_CONTEXT_1_1__PL_MASK) == 0) | |
591 | single_step_once(regs); | |
592 | return 0; | |
593 | } | |
594 | panic("work_pending: bad flags %#x\n", thread_info_flags); | |
595 | } | |
596 | ||
bc4cf2bb | 597 | /* Note there is an implicit fifth argument if (clone_flags & CLONE_SETTLS). */ |
d929b6ae CM |
598 | SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp, |
599 | void __user *, parent_tidptr, void __user *, child_tidptr, | |
600 | struct pt_regs *, regs) | |
867e359b CM |
601 | { |
602 | if (!newsp) | |
603 | newsp = regs->sp; | |
604 | return do_fork(clone_flags, newsp, regs, 0, | |
605 | parent_tidptr, child_tidptr); | |
606 | } | |
607 | ||
867e359b CM |
608 | /* |
609 | * sys_execve() executes a new program. | |
610 | */ | |
d929b6ae CM |
611 | SYSCALL_DEFINE4(execve, const char __user *, path, |
612 | const char __user *const __user *, argv, | |
613 | const char __user *const __user *, envp, | |
614 | struct pt_regs *, regs) | |
867e359b | 615 | { |
0707ad30 | 616 | long error; |
867e359b CM |
617 | char *filename; |
618 | ||
619 | filename = getname(path); | |
620 | error = PTR_ERR(filename); | |
621 | if (IS_ERR(filename)) | |
622 | goto out; | |
623 | error = do_execve(filename, argv, envp, regs); | |
624 | putname(filename); | |
04f7a3f1 CM |
625 | if (error == 0) |
626 | single_step_execve(); | |
867e359b CM |
627 | out: |
628 | return error; | |
629 | } | |
630 | ||
631 | #ifdef CONFIG_COMPAT | |
d929b6ae | 632 | long compat_sys_execve(const char __user *path, |
18aecc2b CM |
633 | compat_uptr_t __user *argv, |
634 | compat_uptr_t __user *envp, | |
d929b6ae | 635 | struct pt_regs *regs) |
867e359b | 636 | { |
0707ad30 | 637 | long error; |
867e359b CM |
638 | char *filename; |
639 | ||
640 | filename = getname(path); | |
641 | error = PTR_ERR(filename); | |
642 | if (IS_ERR(filename)) | |
643 | goto out; | |
644 | error = compat_do_execve(filename, argv, envp, regs); | |
645 | putname(filename); | |
04f7a3f1 CM |
646 | if (error == 0) |
647 | single_step_execve(); | |
867e359b CM |
648 | out: |
649 | return error; | |
650 | } | |
651 | #endif | |
652 | ||
653 | unsigned long get_wchan(struct task_struct *p) | |
654 | { | |
655 | struct KBacktraceIterator kbt; | |
656 | ||
657 | if (!p || p == current || p->state == TASK_RUNNING) | |
658 | return 0; | |
659 | ||
660 | for (KBacktraceIterator_init(&kbt, p, NULL); | |
661 | !KBacktraceIterator_end(&kbt); | |
662 | KBacktraceIterator_next(&kbt)) { | |
663 | if (!in_sched_functions(kbt.it.pc)) | |
664 | return kbt.it.pc; | |
665 | } | |
666 | ||
667 | return 0; | |
668 | } | |
669 | ||
670 | /* | |
671 | * We pass in lr as zero (cleared in kernel_thread) and the caller | |
672 | * part of the backtrace ABI on the stack also zeroed (in copy_thread) | |
673 | * so that backtraces will stop with this function. | |
674 | * Note that we don't use r0, since copy_thread() clears it. | |
675 | */ | |
676 | static void start_kernel_thread(int dummy, int (*fn)(int), int arg) | |
677 | { | |
678 | do_exit(fn(arg)); | |
679 | } | |
680 | ||
681 | /* | |
682 | * Create a kernel thread | |
683 | */ | |
684 | int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) | |
685 | { | |
686 | struct pt_regs regs; | |
687 | ||
688 | memset(®s, 0, sizeof(regs)); | |
689 | regs.ex1 = PL_ICS_EX1(KERNEL_PL, 0); /* run at kernel PL, no ICS */ | |
690 | regs.pc = (long) start_kernel_thread; | |
691 | regs.flags = PT_FLAGS_CALLER_SAVES; /* need to restore r1 and r2 */ | |
692 | regs.regs[1] = (long) fn; /* function pointer */ | |
693 | regs.regs[2] = (long) arg; /* parameter register */ | |
694 | ||
695 | /* Ok, create the new process.. */ | |
696 | return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, | |
697 | 0, NULL, NULL); | |
698 | } | |
699 | EXPORT_SYMBOL(kernel_thread); | |
700 | ||
701 | /* Flush thread state. */ | |
702 | void flush_thread(void) | |
703 | { | |
704 | /* Nothing */ | |
705 | } | |
706 | ||
707 | /* | |
708 | * Free current thread data structures etc.. | |
709 | */ | |
710 | void exit_thread(void) | |
711 | { | |
712 | /* Nothing */ | |
713 | } | |
714 | ||
867e359b CM |
715 | void show_regs(struct pt_regs *regs) |
716 | { | |
717 | struct task_struct *tsk = validate_current(); | |
0707ad30 CM |
718 | int i; |
719 | ||
720 | pr_err("\n"); | |
721 | pr_err(" Pid: %d, comm: %20s, CPU: %d\n", | |
867e359b | 722 | tsk->pid, tsk->comm, smp_processor_id()); |
0707ad30 CM |
723 | #ifdef __tilegx__ |
724 | for (i = 0; i < 51; i += 3) | |
725 | pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT" r%-2d: "REGFMT"\n", | |
726 | i, regs->regs[i], i+1, regs->regs[i+1], | |
727 | i+2, regs->regs[i+2]); | |
728 | pr_err(" r51: "REGFMT" r52: "REGFMT" tp : "REGFMT"\n", | |
729 | regs->regs[51], regs->regs[52], regs->tp); | |
730 | pr_err(" sp : "REGFMT" lr : "REGFMT"\n", regs->sp, regs->lr); | |
731 | #else | |
7040dea4 | 732 | for (i = 0; i < 52; i += 4) |
0707ad30 CM |
733 | pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT |
734 | " r%-2d: "REGFMT" r%-2d: "REGFMT"\n", | |
735 | i, regs->regs[i], i+1, regs->regs[i+1], | |
736 | i+2, regs->regs[i+2], i+3, regs->regs[i+3]); | |
737 | pr_err(" r52: "REGFMT" tp : "REGFMT" sp : "REGFMT" lr : "REGFMT"\n", | |
738 | regs->regs[52], regs->tp, regs->sp, regs->lr); | |
739 | #endif | |
740 | pr_err(" pc : "REGFMT" ex1: %ld faultnum: %ld\n", | |
867e359b CM |
741 | regs->pc, regs->ex1, regs->faultnum); |
742 | ||
743 | dump_stack_regs(regs); | |
744 | } |