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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 | 30 | #include <asm/stack.h> |
34f2c0ac | 31 | #include <asm/switch_to.h> |
867e359b | 32 | #include <asm/homecache.h> |
0707ad30 | 33 | #include <asm/syscalls.h> |
313ce674 | 34 | #include <asm/traps.h> |
bd119c69 | 35 | #include <asm/setup.h> |
0707ad30 CM |
36 | #ifdef CONFIG_HARDWALL |
37 | #include <asm/hardwall.h> | |
38 | #endif | |
867e359b CM |
39 | #include <arch/chip.h> |
40 | #include <arch/abi.h> | |
bd119c69 | 41 | #include <arch/sim_def.h> |
867e359b CM |
42 | |
43 | ||
44 | /* | |
45 | * Use the (x86) "idle=poll" option to prefer low latency when leaving the | |
46 | * idle loop over low power while in the idle loop, e.g. if we have | |
47 | * one thread per core and we want to get threads out of futex waits fast. | |
48 | */ | |
49 | static int no_idle_nap; | |
50 | static int __init idle_setup(char *str) | |
51 | { | |
52 | if (!str) | |
53 | return -EINVAL; | |
54 | ||
55 | if (!strcmp(str, "poll")) { | |
0707ad30 | 56 | pr_info("using polling idle threads.\n"); |
867e359b CM |
57 | no_idle_nap = 1; |
58 | } else if (!strcmp(str, "halt")) | |
59 | no_idle_nap = 0; | |
60 | else | |
61 | return -1; | |
62 | ||
63 | return 0; | |
64 | } | |
65 | early_param("idle", idle_setup); | |
66 | ||
67 | /* | |
68 | * The idle thread. There's no useful work to be | |
69 | * done, so just try to conserve power and have a | |
70 | * low exit latency (ie sit in a loop waiting for | |
71 | * somebody to say that they'd like to reschedule) | |
72 | */ | |
73 | void cpu_idle(void) | |
74 | { | |
867e359b CM |
75 | int cpu = smp_processor_id(); |
76 | ||
77 | ||
78 | current_thread_info()->status |= TS_POLLING; | |
79 | ||
80 | if (no_idle_nap) { | |
81 | while (1) { | |
82 | while (!need_resched()) | |
83 | cpu_relax(); | |
84 | schedule(); | |
85 | } | |
86 | } | |
87 | ||
88 | /* endless idle loop with no priority at all */ | |
89 | while (1) { | |
1268fbc7 FW |
90 | tick_nohz_idle_enter(); |
91 | rcu_idle_enter(); | |
867e359b CM |
92 | while (!need_resched()) { |
93 | if (cpu_is_offline(cpu)) | |
94 | BUG(); /* no HOTPLUG_CPU */ | |
95 | ||
96 | local_irq_disable(); | |
97 | __get_cpu_var(irq_stat).idle_timestamp = jiffies; | |
98 | current_thread_info()->status &= ~TS_POLLING; | |
99 | /* | |
100 | * TS_POLLING-cleared state must be visible before we | |
101 | * test NEED_RESCHED: | |
102 | */ | |
103 | smp_mb(); | |
104 | ||
105 | if (!need_resched()) | |
106 | _cpu_idle(); | |
107 | else | |
108 | local_irq_enable(); | |
109 | current_thread_info()->status |= TS_POLLING; | |
110 | } | |
1268fbc7 FW |
111 | rcu_idle_exit(); |
112 | tick_nohz_idle_exit(); | |
bd2f5536 | 113 | schedule_preempt_disabled(); |
867e359b CM |
114 | } |
115 | } | |
116 | ||
867e359b | 117 | /* |
d909a81b | 118 | * Release a thread_info structure |
867e359b | 119 | */ |
d909a81b | 120 | void arch_release_thread_info(struct thread_info *info) |
867e359b CM |
121 | { |
122 | struct single_step_state *step_state = info->step_state; | |
123 | ||
0707ad30 CM |
124 | #ifdef CONFIG_HARDWALL |
125 | /* | |
126 | * We free a thread_info from the context of the task that has | |
127 | * been scheduled next, so the original task is already dead. | |
128 | * Calling deactivate here just frees up the data structures. | |
129 | * If the task we're freeing held the last reference to a | |
130 | * hardwall fd, it would have been released prior to this point | |
b8ace083 CM |
131 | * anyway via exit_files(), and the hardwall_task.info pointers |
132 | * would be NULL by now. | |
0707ad30 | 133 | */ |
b8ace083 | 134 | hardwall_deactivate_all(info->task); |
0707ad30 | 135 | #endif |
867e359b CM |
136 | |
137 | if (step_state) { | |
138 | ||
139 | /* | |
140 | * FIXME: we don't munmap step_state->buffer | |
141 | * because the mm_struct for this process (info->task->mm) | |
142 | * has already been zeroed in exit_mm(). Keeping a | |
143 | * reference to it here seems like a bad move, so this | |
144 | * means we can't munmap() the buffer, and therefore if we | |
145 | * ptrace multiple threads in a process, we will slowly | |
146 | * leak user memory. (Note that as soon as the last | |
147 | * thread in a process dies, we will reclaim all user | |
148 | * memory including single-step buffers in the usual way.) | |
149 | * We should either assign a kernel VA to this buffer | |
150 | * somehow, or we should associate the buffer(s) with the | |
151 | * mm itself so we can clean them up that way. | |
152 | */ | |
153 | kfree(step_state); | |
154 | } | |
867e359b CM |
155 | } |
156 | ||
157 | static void save_arch_state(struct thread_struct *t); | |
158 | ||
867e359b CM |
159 | int copy_thread(unsigned long clone_flags, unsigned long sp, |
160 | unsigned long stack_size, | |
161 | struct task_struct *p, struct pt_regs *regs) | |
162 | { | |
163 | struct pt_regs *childregs; | |
164 | unsigned long ksp; | |
165 | ||
166 | /* | |
167 | * When creating a new kernel thread we pass sp as zero. | |
168 | * Assign it to a reasonable value now that we have the stack. | |
169 | */ | |
170 | if (sp == 0 && regs->ex1 == PL_ICS_EX1(KERNEL_PL, 0)) | |
171 | sp = KSTK_TOP(p); | |
172 | ||
173 | /* | |
174 | * Do not clone step state from the parent; each thread | |
175 | * must make its own lazily. | |
176 | */ | |
177 | task_thread_info(p)->step_state = NULL; | |
178 | ||
179 | /* | |
180 | * Start new thread in ret_from_fork so it schedules properly | |
181 | * and then return from interrupt like the parent. | |
182 | */ | |
183 | p->thread.pc = (unsigned long) ret_from_fork; | |
184 | ||
185 | /* Save user stack top pointer so we can ID the stack vm area later. */ | |
186 | p->thread.usp0 = sp; | |
187 | ||
188 | /* Record the pid of the process that created this one. */ | |
189 | p->thread.creator_pid = current->pid; | |
190 | ||
191 | /* | |
192 | * Copy the registers onto the kernel stack so the | |
193 | * return-from-interrupt code will reload it into registers. | |
194 | */ | |
195 | childregs = task_pt_regs(p); | |
196 | *childregs = *regs; | |
197 | childregs->regs[0] = 0; /* return value is zero */ | |
198 | childregs->sp = sp; /* override with new user stack pointer */ | |
199 | ||
bc4cf2bb CM |
200 | /* |
201 | * If CLONE_SETTLS is set, set "tp" in the new task to "r4", | |
202 | * which is passed in as arg #5 to sys_clone(). | |
203 | */ | |
204 | if (clone_flags & CLONE_SETTLS) | |
205 | childregs->tp = regs->regs[4]; | |
206 | ||
867e359b CM |
207 | /* |
208 | * Copy the callee-saved registers from the passed pt_regs struct | |
209 | * into the context-switch callee-saved registers area. | |
d6f0f22c CM |
210 | * This way when we start the interrupt-return sequence, the |
211 | * callee-save registers will be correctly in registers, which | |
212 | * is how we assume the compiler leaves them as we start doing | |
213 | * the normal return-from-interrupt path after calling C code. | |
867e359b CM |
214 | * Zero out the C ABI save area to mark the top of the stack. |
215 | */ | |
216 | ksp = (unsigned long) childregs; | |
217 | ksp -= C_ABI_SAVE_AREA_SIZE; /* interrupt-entry save area */ | |
218 | ((long *)ksp)[0] = ((long *)ksp)[1] = 0; | |
219 | ksp -= CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long); | |
220 | memcpy((void *)ksp, ®s->regs[CALLEE_SAVED_FIRST_REG], | |
221 | CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long)); | |
222 | ksp -= C_ABI_SAVE_AREA_SIZE; /* __switch_to() save area */ | |
223 | ((long *)ksp)[0] = ((long *)ksp)[1] = 0; | |
224 | p->thread.ksp = ksp; | |
225 | ||
226 | #if CHIP_HAS_TILE_DMA() | |
227 | /* | |
228 | * No DMA in the new thread. We model this on the fact that | |
229 | * fork() clears the pending signals, alarms, and aio for the child. | |
230 | */ | |
231 | memset(&p->thread.tile_dma_state, 0, sizeof(struct tile_dma_state)); | |
232 | memset(&p->thread.dma_async_tlb, 0, sizeof(struct async_tlb)); | |
233 | #endif | |
234 | ||
235 | #if CHIP_HAS_SN_PROC() | |
236 | /* Likewise, the new thread is not running static processor code. */ | |
237 | p->thread.sn_proc_running = 0; | |
238 | memset(&p->thread.sn_async_tlb, 0, sizeof(struct async_tlb)); | |
239 | #endif | |
240 | ||
241 | #if CHIP_HAS_PROC_STATUS_SPR() | |
242 | /* New thread has its miscellaneous processor state bits clear. */ | |
243 | p->thread.proc_status = 0; | |
244 | #endif | |
245 | ||
0707ad30 CM |
246 | #ifdef CONFIG_HARDWALL |
247 | /* New thread does not own any networks. */ | |
b8ace083 CM |
248 | memset(&p->thread.hardwall[0], 0, |
249 | sizeof(struct hardwall_task) * HARDWALL_TYPES); | |
0707ad30 | 250 | #endif |
867e359b CM |
251 | |
252 | ||
253 | /* | |
254 | * Start the new thread with the current architecture state | |
255 | * (user interrupt masks, etc.). | |
256 | */ | |
257 | save_arch_state(&p->thread); | |
258 | ||
259 | return 0; | |
260 | } | |
261 | ||
262 | /* | |
263 | * Return "current" if it looks plausible, or else a pointer to a dummy. | |
264 | * This can be helpful if we are just trying to emit a clean panic. | |
265 | */ | |
266 | struct task_struct *validate_current(void) | |
267 | { | |
268 | static struct task_struct corrupt = { .comm = "<corrupt>" }; | |
269 | struct task_struct *tsk = current; | |
270 | if (unlikely((unsigned long)tsk < PAGE_OFFSET || | |
b287f696 | 271 | (high_memory && (void *)tsk > high_memory) || |
867e359b | 272 | ((unsigned long)tsk & (__alignof__(*tsk) - 1)) != 0)) { |
0707ad30 | 273 | pr_err("Corrupt 'current' %p (sp %#lx)\n", tsk, stack_pointer); |
867e359b CM |
274 | tsk = &corrupt; |
275 | } | |
276 | return tsk; | |
277 | } | |
278 | ||
279 | /* Take and return the pointer to the previous task, for schedule_tail(). */ | |
280 | struct task_struct *sim_notify_fork(struct task_struct *prev) | |
281 | { | |
282 | struct task_struct *tsk = current; | |
283 | __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_FORK_PARENT | | |
284 | (tsk->thread.creator_pid << _SIM_CONTROL_OPERATOR_BITS)); | |
285 | __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_FORK | | |
286 | (tsk->pid << _SIM_CONTROL_OPERATOR_BITS)); | |
287 | return prev; | |
288 | } | |
289 | ||
290 | int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs) | |
291 | { | |
292 | struct pt_regs *ptregs = task_pt_regs(tsk); | |
293 | elf_core_copy_regs(regs, ptregs); | |
294 | return 1; | |
295 | } | |
296 | ||
297 | #if CHIP_HAS_TILE_DMA() | |
298 | ||
299 | /* Allow user processes to access the DMA SPRs */ | |
300 | void grant_dma_mpls(void) | |
301 | { | |
a78c942d CM |
302 | #if CONFIG_KERNEL_PL == 2 |
303 | __insn_mtspr(SPR_MPL_DMA_CPL_SET_1, 1); | |
304 | __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_1, 1); | |
305 | #else | |
867e359b CM |
306 | __insn_mtspr(SPR_MPL_DMA_CPL_SET_0, 1); |
307 | __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_0, 1); | |
a78c942d | 308 | #endif |
867e359b CM |
309 | } |
310 | ||
311 | /* Forbid user processes from accessing the DMA SPRs */ | |
312 | void restrict_dma_mpls(void) | |
313 | { | |
a78c942d CM |
314 | #if CONFIG_KERNEL_PL == 2 |
315 | __insn_mtspr(SPR_MPL_DMA_CPL_SET_2, 1); | |
316 | __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_2, 1); | |
317 | #else | |
867e359b CM |
318 | __insn_mtspr(SPR_MPL_DMA_CPL_SET_1, 1); |
319 | __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_1, 1); | |
a78c942d | 320 | #endif |
867e359b CM |
321 | } |
322 | ||
323 | /* Pause the DMA engine, then save off its state registers. */ | |
324 | static void save_tile_dma_state(struct tile_dma_state *dma) | |
325 | { | |
326 | unsigned long state = __insn_mfspr(SPR_DMA_USER_STATUS); | |
327 | unsigned long post_suspend_state; | |
328 | ||
329 | /* If we're running, suspend the engine. */ | |
330 | if ((state & DMA_STATUS_MASK) == SPR_DMA_STATUS__RUNNING_MASK) | |
331 | __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__SUSPEND_MASK); | |
332 | ||
333 | /* | |
334 | * Wait for the engine to idle, then save regs. Note that we | |
335 | * want to record the "running" bit from before suspension, | |
336 | * and the "done" bit from after, so that we can properly | |
337 | * distinguish a case where the user suspended the engine from | |
338 | * the case where the kernel suspended as part of the context | |
339 | * swap. | |
340 | */ | |
341 | do { | |
342 | post_suspend_state = __insn_mfspr(SPR_DMA_USER_STATUS); | |
343 | } while (post_suspend_state & SPR_DMA_STATUS__BUSY_MASK); | |
344 | ||
345 | dma->src = __insn_mfspr(SPR_DMA_SRC_ADDR); | |
346 | dma->src_chunk = __insn_mfspr(SPR_DMA_SRC_CHUNK_ADDR); | |
347 | dma->dest = __insn_mfspr(SPR_DMA_DST_ADDR); | |
348 | dma->dest_chunk = __insn_mfspr(SPR_DMA_DST_CHUNK_ADDR); | |
349 | dma->strides = __insn_mfspr(SPR_DMA_STRIDE); | |
350 | dma->chunk_size = __insn_mfspr(SPR_DMA_CHUNK_SIZE); | |
351 | dma->byte = __insn_mfspr(SPR_DMA_BYTE); | |
352 | dma->status = (state & SPR_DMA_STATUS__RUNNING_MASK) | | |
353 | (post_suspend_state & SPR_DMA_STATUS__DONE_MASK); | |
354 | } | |
355 | ||
356 | /* Restart a DMA that was running before we were context-switched out. */ | |
357 | static void restore_tile_dma_state(struct thread_struct *t) | |
358 | { | |
359 | const struct tile_dma_state *dma = &t->tile_dma_state; | |
360 | ||
361 | /* | |
362 | * The only way to restore the done bit is to run a zero | |
363 | * length transaction. | |
364 | */ | |
365 | if ((dma->status & SPR_DMA_STATUS__DONE_MASK) && | |
366 | !(__insn_mfspr(SPR_DMA_USER_STATUS) & SPR_DMA_STATUS__DONE_MASK)) { | |
367 | __insn_mtspr(SPR_DMA_BYTE, 0); | |
368 | __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__REQUEST_MASK); | |
369 | while (__insn_mfspr(SPR_DMA_USER_STATUS) & | |
370 | SPR_DMA_STATUS__BUSY_MASK) | |
371 | ; | |
372 | } | |
373 | ||
374 | __insn_mtspr(SPR_DMA_SRC_ADDR, dma->src); | |
375 | __insn_mtspr(SPR_DMA_SRC_CHUNK_ADDR, dma->src_chunk); | |
376 | __insn_mtspr(SPR_DMA_DST_ADDR, dma->dest); | |
377 | __insn_mtspr(SPR_DMA_DST_CHUNK_ADDR, dma->dest_chunk); | |
378 | __insn_mtspr(SPR_DMA_STRIDE, dma->strides); | |
379 | __insn_mtspr(SPR_DMA_CHUNK_SIZE, dma->chunk_size); | |
380 | __insn_mtspr(SPR_DMA_BYTE, dma->byte); | |
381 | ||
382 | /* | |
383 | * Restart the engine if we were running and not done. | |
384 | * Clear a pending async DMA fault that we were waiting on return | |
385 | * to user space to execute, since we expect the DMA engine | |
386 | * to regenerate those faults for us now. Note that we don't | |
387 | * try to clear the TIF_ASYNC_TLB flag, since it's relatively | |
388 | * harmless if set, and it covers both DMA and the SN processor. | |
389 | */ | |
390 | if ((dma->status & DMA_STATUS_MASK) == SPR_DMA_STATUS__RUNNING_MASK) { | |
391 | t->dma_async_tlb.fault_num = 0; | |
392 | __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__REQUEST_MASK); | |
393 | } | |
394 | } | |
395 | ||
396 | #endif | |
397 | ||
398 | static void save_arch_state(struct thread_struct *t) | |
399 | { | |
400 | #if CHIP_HAS_SPLIT_INTR_MASK() | |
401 | t->interrupt_mask = __insn_mfspr(SPR_INTERRUPT_MASK_0_0) | | |
402 | ((u64)__insn_mfspr(SPR_INTERRUPT_MASK_0_1) << 32); | |
403 | #else | |
404 | t->interrupt_mask = __insn_mfspr(SPR_INTERRUPT_MASK_0); | |
405 | #endif | |
406 | t->ex_context[0] = __insn_mfspr(SPR_EX_CONTEXT_0_0); | |
407 | t->ex_context[1] = __insn_mfspr(SPR_EX_CONTEXT_0_1); | |
408 | t->system_save[0] = __insn_mfspr(SPR_SYSTEM_SAVE_0_0); | |
409 | t->system_save[1] = __insn_mfspr(SPR_SYSTEM_SAVE_0_1); | |
410 | t->system_save[2] = __insn_mfspr(SPR_SYSTEM_SAVE_0_2); | |
411 | t->system_save[3] = __insn_mfspr(SPR_SYSTEM_SAVE_0_3); | |
412 | t->intctrl_0 = __insn_mfspr(SPR_INTCTRL_0_STATUS); | |
413 | #if CHIP_HAS_PROC_STATUS_SPR() | |
414 | t->proc_status = __insn_mfspr(SPR_PROC_STATUS); | |
415 | #endif | |
a802fc68 CM |
416 | #if !CHIP_HAS_FIXED_INTVEC_BASE() |
417 | t->interrupt_vector_base = __insn_mfspr(SPR_INTERRUPT_VECTOR_BASE_0); | |
418 | #endif | |
419 | #if CHIP_HAS_TILE_RTF_HWM() | |
420 | t->tile_rtf_hwm = __insn_mfspr(SPR_TILE_RTF_HWM); | |
421 | #endif | |
422 | #if CHIP_HAS_DSTREAM_PF() | |
423 | t->dstream_pf = __insn_mfspr(SPR_DSTREAM_PF); | |
424 | #endif | |
867e359b CM |
425 | } |
426 | ||
427 | static void restore_arch_state(const struct thread_struct *t) | |
428 | { | |
429 | #if CHIP_HAS_SPLIT_INTR_MASK() | |
430 | __insn_mtspr(SPR_INTERRUPT_MASK_0_0, (u32) t->interrupt_mask); | |
431 | __insn_mtspr(SPR_INTERRUPT_MASK_0_1, t->interrupt_mask >> 32); | |
432 | #else | |
433 | __insn_mtspr(SPR_INTERRUPT_MASK_0, t->interrupt_mask); | |
434 | #endif | |
435 | __insn_mtspr(SPR_EX_CONTEXT_0_0, t->ex_context[0]); | |
436 | __insn_mtspr(SPR_EX_CONTEXT_0_1, t->ex_context[1]); | |
437 | __insn_mtspr(SPR_SYSTEM_SAVE_0_0, t->system_save[0]); | |
438 | __insn_mtspr(SPR_SYSTEM_SAVE_0_1, t->system_save[1]); | |
439 | __insn_mtspr(SPR_SYSTEM_SAVE_0_2, t->system_save[2]); | |
440 | __insn_mtspr(SPR_SYSTEM_SAVE_0_3, t->system_save[3]); | |
441 | __insn_mtspr(SPR_INTCTRL_0_STATUS, t->intctrl_0); | |
442 | #if CHIP_HAS_PROC_STATUS_SPR() | |
443 | __insn_mtspr(SPR_PROC_STATUS, t->proc_status); | |
444 | #endif | |
a802fc68 CM |
445 | #if !CHIP_HAS_FIXED_INTVEC_BASE() |
446 | __insn_mtspr(SPR_INTERRUPT_VECTOR_BASE_0, t->interrupt_vector_base); | |
447 | #endif | |
867e359b | 448 | #if CHIP_HAS_TILE_RTF_HWM() |
a802fc68 CM |
449 | __insn_mtspr(SPR_TILE_RTF_HWM, t->tile_rtf_hwm); |
450 | #endif | |
451 | #if CHIP_HAS_DSTREAM_PF() | |
452 | __insn_mtspr(SPR_DSTREAM_PF, t->dstream_pf); | |
867e359b CM |
453 | #endif |
454 | } | |
455 | ||
456 | ||
457 | void _prepare_arch_switch(struct task_struct *next) | |
458 | { | |
459 | #if CHIP_HAS_SN_PROC() | |
460 | int snctl; | |
461 | #endif | |
462 | #if CHIP_HAS_TILE_DMA() | |
463 | struct tile_dma_state *dma = ¤t->thread.tile_dma_state; | |
464 | if (dma->enabled) | |
465 | save_tile_dma_state(dma); | |
466 | #endif | |
467 | #if CHIP_HAS_SN_PROC() | |
468 | /* | |
469 | * Suspend the static network processor if it was running. | |
470 | * We do not suspend the fabric itself, just like we don't | |
471 | * try to suspend the UDN. | |
472 | */ | |
473 | snctl = __insn_mfspr(SPR_SNCTL); | |
474 | current->thread.sn_proc_running = | |
475 | (snctl & SPR_SNCTL__FRZPROC_MASK) == 0; | |
476 | if (current->thread.sn_proc_running) | |
477 | __insn_mtspr(SPR_SNCTL, snctl | SPR_SNCTL__FRZPROC_MASK); | |
478 | #endif | |
479 | } | |
480 | ||
481 | ||
867e359b CM |
482 | struct task_struct *__sched _switch_to(struct task_struct *prev, |
483 | struct task_struct *next) | |
484 | { | |
485 | /* DMA state is already saved; save off other arch state. */ | |
486 | save_arch_state(&prev->thread); | |
487 | ||
488 | #if CHIP_HAS_TILE_DMA() | |
489 | /* | |
490 | * Restore DMA in new task if desired. | |
491 | * Note that it is only safe to restart here since interrupts | |
492 | * are disabled, so we can't take any DMATLB miss or access | |
493 | * interrupts before we have finished switching stacks. | |
494 | */ | |
495 | if (next->thread.tile_dma_state.enabled) { | |
496 | restore_tile_dma_state(&next->thread); | |
497 | grant_dma_mpls(); | |
498 | } else { | |
499 | restrict_dma_mpls(); | |
500 | } | |
501 | #endif | |
502 | ||
503 | /* Restore other arch state. */ | |
504 | restore_arch_state(&next->thread); | |
505 | ||
506 | #if CHIP_HAS_SN_PROC() | |
507 | /* | |
508 | * Restart static network processor in the new process | |
509 | * if it was running before. | |
510 | */ | |
511 | if (next->thread.sn_proc_running) { | |
512 | int snctl = __insn_mfspr(SPR_SNCTL); | |
513 | __insn_mtspr(SPR_SNCTL, snctl & ~SPR_SNCTL__FRZPROC_MASK); | |
514 | } | |
515 | #endif | |
516 | ||
0707ad30 CM |
517 | #ifdef CONFIG_HARDWALL |
518 | /* Enable or disable access to the network registers appropriately. */ | |
b8ace083 | 519 | hardwall_switch_tasks(prev, next); |
0707ad30 | 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). | |
a78c942d | 526 | * Pass the value to use for SYSTEM_SAVE_K_0 when we reset our sp. |
867e359b CM |
527 | */ |
528 | return __switch_to(prev, next, next_current_ksp0(next)); | |
529 | } | |
530 | ||
313ce674 CM |
531 | /* |
532 | * This routine is called on return from interrupt if any of the | |
533 | * TIF_WORK_MASK flags are set in thread_info->flags. It is | |
534 | * entered with interrupts disabled so we don't miss an event | |
535 | * that modified the thread_info flags. If any flag is set, we | |
536 | * handle it and return, and the calling assembly code will | |
537 | * re-disable interrupts, reload the thread flags, and call back | |
538 | * if more flags need to be handled. | |
539 | * | |
540 | * We return whether we need to check the thread_info flags again | |
541 | * or not. Note that we don't clear TIF_SINGLESTEP here, so it's | |
542 | * important that it be tested last, and then claim that we don't | |
543 | * need to recheck the flags. | |
544 | */ | |
545 | int do_work_pending(struct pt_regs *regs, u32 thread_info_flags) | |
546 | { | |
fc327e26 CM |
547 | /* If we enter in kernel mode, do nothing and exit the caller loop. */ |
548 | if (!user_mode(regs)) | |
549 | return 0; | |
550 | ||
313ce674 CM |
551 | if (thread_info_flags & _TIF_NEED_RESCHED) { |
552 | schedule(); | |
553 | return 1; | |
554 | } | |
555 | #if CHIP_HAS_TILE_DMA() || CHIP_HAS_SN_PROC() | |
556 | if (thread_info_flags & _TIF_ASYNC_TLB) { | |
557 | do_async_page_fault(regs); | |
558 | return 1; | |
559 | } | |
560 | #endif | |
561 | if (thread_info_flags & _TIF_SIGPENDING) { | |
562 | do_signal(regs); | |
563 | return 1; | |
564 | } | |
565 | if (thread_info_flags & _TIF_NOTIFY_RESUME) { | |
566 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
567 | tracehook_notify_resume(regs); | |
313ce674 CM |
568 | return 1; |
569 | } | |
570 | if (thread_info_flags & _TIF_SINGLESTEP) { | |
fc327e26 | 571 | single_step_once(regs); |
313ce674 CM |
572 | return 0; |
573 | } | |
574 | panic("work_pending: bad flags %#x\n", thread_info_flags); | |
575 | } | |
576 | ||
bc4cf2bb | 577 | /* Note there is an implicit fifth argument if (clone_flags & CLONE_SETTLS). */ |
d929b6ae CM |
578 | SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp, |
579 | void __user *, parent_tidptr, void __user *, child_tidptr, | |
580 | struct pt_regs *, regs) | |
867e359b CM |
581 | { |
582 | if (!newsp) | |
583 | newsp = regs->sp; | |
584 | return do_fork(clone_flags, newsp, regs, 0, | |
585 | parent_tidptr, child_tidptr); | |
586 | } | |
587 | ||
867e359b CM |
588 | /* |
589 | * sys_execve() executes a new program. | |
590 | */ | |
d929b6ae CM |
591 | SYSCALL_DEFINE4(execve, const char __user *, path, |
592 | const char __user *const __user *, argv, | |
593 | const char __user *const __user *, envp, | |
594 | struct pt_regs *, regs) | |
867e359b | 595 | { |
0707ad30 | 596 | long error; |
91a27b2a | 597 | struct filename *filename; |
867e359b CM |
598 | |
599 | filename = getname(path); | |
600 | error = PTR_ERR(filename); | |
601 | if (IS_ERR(filename)) | |
602 | goto out; | |
91a27b2a | 603 | error = do_execve(filename->name, argv, envp, regs); |
867e359b | 604 | putname(filename); |
04f7a3f1 CM |
605 | if (error == 0) |
606 | single_step_execve(); | |
867e359b CM |
607 | out: |
608 | return error; | |
609 | } | |
610 | ||
611 | #ifdef CONFIG_COMPAT | |
d929b6ae | 612 | long compat_sys_execve(const char __user *path, |
18aecc2b CM |
613 | compat_uptr_t __user *argv, |
614 | compat_uptr_t __user *envp, | |
d929b6ae | 615 | struct pt_regs *regs) |
867e359b | 616 | { |
0707ad30 | 617 | long error; |
91a27b2a | 618 | struct filename *filename; |
867e359b CM |
619 | |
620 | filename = getname(path); | |
621 | error = PTR_ERR(filename); | |
622 | if (IS_ERR(filename)) | |
623 | goto out; | |
91a27b2a | 624 | error = compat_do_execve(filename->name, argv, envp, regs); |
867e359b | 625 | putname(filename); |
04f7a3f1 CM |
626 | if (error == 0) |
627 | single_step_execve(); | |
867e359b CM |
628 | out: |
629 | return error; | |
630 | } | |
631 | #endif | |
632 | ||
633 | unsigned long get_wchan(struct task_struct *p) | |
634 | { | |
635 | struct KBacktraceIterator kbt; | |
636 | ||
637 | if (!p || p == current || p->state == TASK_RUNNING) | |
638 | return 0; | |
639 | ||
640 | for (KBacktraceIterator_init(&kbt, p, NULL); | |
641 | !KBacktraceIterator_end(&kbt); | |
642 | KBacktraceIterator_next(&kbt)) { | |
643 | if (!in_sched_functions(kbt.it.pc)) | |
644 | return kbt.it.pc; | |
645 | } | |
646 | ||
647 | return 0; | |
648 | } | |
649 | ||
650 | /* | |
651 | * We pass in lr as zero (cleared in kernel_thread) and the caller | |
652 | * part of the backtrace ABI on the stack also zeroed (in copy_thread) | |
653 | * so that backtraces will stop with this function. | |
654 | * Note that we don't use r0, since copy_thread() clears it. | |
655 | */ | |
656 | static void start_kernel_thread(int dummy, int (*fn)(int), int arg) | |
657 | { | |
658 | do_exit(fn(arg)); | |
659 | } | |
660 | ||
661 | /* | |
662 | * Create a kernel thread | |
663 | */ | |
664 | int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) | |
665 | { | |
666 | struct pt_regs regs; | |
667 | ||
668 | memset(®s, 0, sizeof(regs)); | |
669 | regs.ex1 = PL_ICS_EX1(KERNEL_PL, 0); /* run at kernel PL, no ICS */ | |
670 | regs.pc = (long) start_kernel_thread; | |
671 | regs.flags = PT_FLAGS_CALLER_SAVES; /* need to restore r1 and r2 */ | |
672 | regs.regs[1] = (long) fn; /* function pointer */ | |
673 | regs.regs[2] = (long) arg; /* parameter register */ | |
674 | ||
675 | /* Ok, create the new process.. */ | |
676 | return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, | |
677 | 0, NULL, NULL); | |
678 | } | |
679 | EXPORT_SYMBOL(kernel_thread); | |
680 | ||
681 | /* Flush thread state. */ | |
682 | void flush_thread(void) | |
683 | { | |
684 | /* Nothing */ | |
685 | } | |
686 | ||
687 | /* | |
688 | * Free current thread data structures etc.. | |
689 | */ | |
690 | void exit_thread(void) | |
691 | { | |
692 | /* Nothing */ | |
693 | } | |
694 | ||
867e359b CM |
695 | void show_regs(struct pt_regs *regs) |
696 | { | |
697 | struct task_struct *tsk = validate_current(); | |
0707ad30 CM |
698 | int i; |
699 | ||
700 | pr_err("\n"); | |
701 | pr_err(" Pid: %d, comm: %20s, CPU: %d\n", | |
867e359b | 702 | tsk->pid, tsk->comm, smp_processor_id()); |
0707ad30 CM |
703 | #ifdef __tilegx__ |
704 | for (i = 0; i < 51; i += 3) | |
705 | pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT" r%-2d: "REGFMT"\n", | |
706 | i, regs->regs[i], i+1, regs->regs[i+1], | |
707 | i+2, regs->regs[i+2]); | |
708 | pr_err(" r51: "REGFMT" r52: "REGFMT" tp : "REGFMT"\n", | |
709 | regs->regs[51], regs->regs[52], regs->tp); | |
710 | pr_err(" sp : "REGFMT" lr : "REGFMT"\n", regs->sp, regs->lr); | |
711 | #else | |
7040dea4 | 712 | for (i = 0; i < 52; i += 4) |
0707ad30 CM |
713 | pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT |
714 | " r%-2d: "REGFMT" r%-2d: "REGFMT"\n", | |
715 | i, regs->regs[i], i+1, regs->regs[i+1], | |
716 | i+2, regs->regs[i+2], i+3, regs->regs[i+3]); | |
717 | pr_err(" r52: "REGFMT" tp : "REGFMT" sp : "REGFMT" lr : "REGFMT"\n", | |
718 | regs->regs[52], regs->tp, regs->sp, regs->lr); | |
719 | #endif | |
720 | pr_err(" pc : "REGFMT" ex1: %ld faultnum: %ld\n", | |
867e359b CM |
721 | regs->pc, regs->ex1, regs->faultnum); |
722 | ||
723 | dump_stack_regs(regs); | |
724 | } |