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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 | 42 | |
867e359b CM |
43 | /* |
44 | * Use the (x86) "idle=poll" option to prefer low latency when leaving the | |
45 | * idle loop over low power while in the idle loop, e.g. if we have | |
46 | * one thread per core and we want to get threads out of futex waits fast. | |
47 | */ | |
867e359b CM |
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"); |
0dc8153c TG |
55 | cpu_idle_poll_ctrl(true); |
56 | return 0; | |
57 | } else if (!strcmp(str, "halt")) { | |
58 | return 0; | |
59 | } | |
60 | return -1; | |
867e359b CM |
61 | } |
62 | early_param("idle", idle_setup); | |
63 | ||
0dc8153c | 64 | void arch_cpu_idle(void) |
867e359b | 65 | { |
0dc8153c TG |
66 | __get_cpu_var(irq_stat).idle_timestamp = jiffies; |
67 | _cpu_idle(); | |
867e359b CM |
68 | } |
69 | ||
867e359b | 70 | /* |
d909a81b | 71 | * Release a thread_info structure |
867e359b | 72 | */ |
d909a81b | 73 | void arch_release_thread_info(struct thread_info *info) |
867e359b CM |
74 | { |
75 | struct single_step_state *step_state = info->step_state; | |
76 | ||
0707ad30 CM |
77 | #ifdef CONFIG_HARDWALL |
78 | /* | |
79 | * We free a thread_info from the context of the task that has | |
80 | * been scheduled next, so the original task is already dead. | |
81 | * Calling deactivate here just frees up the data structures. | |
82 | * If the task we're freeing held the last reference to a | |
83 | * hardwall fd, it would have been released prior to this point | |
b8ace083 CM |
84 | * anyway via exit_files(), and the hardwall_task.info pointers |
85 | * would be NULL by now. | |
0707ad30 | 86 | */ |
b8ace083 | 87 | hardwall_deactivate_all(info->task); |
0707ad30 | 88 | #endif |
867e359b CM |
89 | |
90 | if (step_state) { | |
91 | ||
92 | /* | |
93 | * FIXME: we don't munmap step_state->buffer | |
94 | * because the mm_struct for this process (info->task->mm) | |
95 | * has already been zeroed in exit_mm(). Keeping a | |
96 | * reference to it here seems like a bad move, so this | |
97 | * means we can't munmap() the buffer, and therefore if we | |
98 | * ptrace multiple threads in a process, we will slowly | |
99 | * leak user memory. (Note that as soon as the last | |
100 | * thread in a process dies, we will reclaim all user | |
101 | * memory including single-step buffers in the usual way.) | |
102 | * We should either assign a kernel VA to this buffer | |
103 | * somehow, or we should associate the buffer(s) with the | |
104 | * mm itself so we can clean them up that way. | |
105 | */ | |
106 | kfree(step_state); | |
107 | } | |
867e359b CM |
108 | } |
109 | ||
110 | static void save_arch_state(struct thread_struct *t); | |
111 | ||
867e359b | 112 | int copy_thread(unsigned long clone_flags, unsigned long sp, |
afa86fc4 | 113 | unsigned long arg, struct task_struct *p) |
867e359b | 114 | { |
e69ddd33 | 115 | struct pt_regs *childregs = task_pt_regs(p); |
867e359b | 116 | unsigned long ksp; |
0f8b9838 | 117 | unsigned long *callee_regs; |
867e359b CM |
118 | |
119 | /* | |
0f8b9838 CM |
120 | * Set up the stack and stack pointer appropriately for the |
121 | * new child to find itself woken up in __switch_to(). | |
122 | * The callee-saved registers must be on the stack to be read; | |
123 | * the new task will then jump to assembly support to handle | |
124 | * calling schedule_tail(), etc., and (for userspace tasks) | |
125 | * returning to the context set up in the pt_regs. | |
867e359b | 126 | */ |
0f8b9838 CM |
127 | ksp = (unsigned long) childregs; |
128 | ksp -= C_ABI_SAVE_AREA_SIZE; /* interrupt-entry save area */ | |
129 | ((long *)ksp)[0] = ((long *)ksp)[1] = 0; | |
130 | ksp -= CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long); | |
131 | callee_regs = (unsigned long *)ksp; | |
132 | ksp -= C_ABI_SAVE_AREA_SIZE; /* __switch_to() save area */ | |
133 | ((long *)ksp)[0] = ((long *)ksp)[1] = 0; | |
134 | p->thread.ksp = ksp; | |
867e359b | 135 | |
0f8b9838 CM |
136 | /* Record the pid of the task that created this one. */ |
137 | p->thread.creator_pid = current->pid; | |
138 | ||
008f1794 | 139 | if (unlikely(p->flags & PF_KTHREAD)) { |
0f8b9838 CM |
140 | /* kernel thread */ |
141 | memset(childregs, 0, sizeof(struct pt_regs)); | |
142 | memset(&callee_regs[2], 0, | |
143 | (CALLEE_SAVED_REGS_COUNT - 2) * sizeof(unsigned long)); | |
144 | callee_regs[0] = sp; /* r30 = function */ | |
145 | callee_regs[1] = arg; /* r31 = arg */ | |
146 | childregs->ex1 = PL_ICS_EX1(KERNEL_PL, 0); | |
147 | p->thread.pc = (unsigned long) ret_from_kernel_thread; | |
148 | return 0; | |
149 | } | |
867e359b CM |
150 | |
151 | /* | |
152 | * Start new thread in ret_from_fork so it schedules properly | |
153 | * and then return from interrupt like the parent. | |
154 | */ | |
155 | p->thread.pc = (unsigned long) ret_from_fork; | |
156 | ||
0f8b9838 CM |
157 | /* |
158 | * Do not clone step state from the parent; each thread | |
159 | * must make its own lazily. | |
160 | */ | |
161 | task_thread_info(p)->step_state = NULL; | |
162 | ||
867e359b CM |
163 | /* |
164 | * Copy the registers onto the kernel stack so the | |
165 | * return-from-interrupt code will reload it into registers. | |
166 | */ | |
008f1794 | 167 | *childregs = *current_pt_regs(); |
867e359b | 168 | childregs->regs[0] = 0; /* return value is zero */ |
008f1794 AV |
169 | if (sp) |
170 | childregs->sp = sp; /* override with new user stack pointer */ | |
171 | memcpy(callee_regs, &childregs->regs[CALLEE_SAVED_FIRST_REG], | |
0f8b9838 | 172 | CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long)); |
867e359b | 173 | |
008f1794 AV |
174 | /* Save user stack top pointer so we can ID the stack vm area later. */ |
175 | p->thread.usp0 = childregs->sp; | |
176 | ||
bc4cf2bb CM |
177 | /* |
178 | * If CLONE_SETTLS is set, set "tp" in the new task to "r4", | |
179 | * which is passed in as arg #5 to sys_clone(). | |
180 | */ | |
181 | if (clone_flags & CLONE_SETTLS) | |
008f1794 | 182 | childregs->tp = childregs->regs[4]; |
bc4cf2bb | 183 | |
867e359b CM |
184 | |
185 | #if CHIP_HAS_TILE_DMA() | |
186 | /* | |
187 | * No DMA in the new thread. We model this on the fact that | |
188 | * fork() clears the pending signals, alarms, and aio for the child. | |
189 | */ | |
190 | memset(&p->thread.tile_dma_state, 0, sizeof(struct tile_dma_state)); | |
191 | memset(&p->thread.dma_async_tlb, 0, sizeof(struct async_tlb)); | |
192 | #endif | |
193 | ||
194 | #if CHIP_HAS_SN_PROC() | |
195 | /* Likewise, the new thread is not running static processor code. */ | |
196 | p->thread.sn_proc_running = 0; | |
197 | memset(&p->thread.sn_async_tlb, 0, sizeof(struct async_tlb)); | |
198 | #endif | |
199 | ||
200 | #if CHIP_HAS_PROC_STATUS_SPR() | |
201 | /* New thread has its miscellaneous processor state bits clear. */ | |
202 | p->thread.proc_status = 0; | |
203 | #endif | |
204 | ||
0707ad30 CM |
205 | #ifdef CONFIG_HARDWALL |
206 | /* New thread does not own any networks. */ | |
b8ace083 CM |
207 | memset(&p->thread.hardwall[0], 0, |
208 | sizeof(struct hardwall_task) * HARDWALL_TYPES); | |
0707ad30 | 209 | #endif |
867e359b CM |
210 | |
211 | ||
212 | /* | |
213 | * Start the new thread with the current architecture state | |
214 | * (user interrupt masks, etc.). | |
215 | */ | |
216 | save_arch_state(&p->thread); | |
217 | ||
218 | return 0; | |
219 | } | |
220 | ||
221 | /* | |
222 | * Return "current" if it looks plausible, or else a pointer to a dummy. | |
223 | * This can be helpful if we are just trying to emit a clean panic. | |
224 | */ | |
225 | struct task_struct *validate_current(void) | |
226 | { | |
227 | static struct task_struct corrupt = { .comm = "<corrupt>" }; | |
228 | struct task_struct *tsk = current; | |
229 | if (unlikely((unsigned long)tsk < PAGE_OFFSET || | |
b287f696 | 230 | (high_memory && (void *)tsk > high_memory) || |
867e359b | 231 | ((unsigned long)tsk & (__alignof__(*tsk) - 1)) != 0)) { |
0707ad30 | 232 | pr_err("Corrupt 'current' %p (sp %#lx)\n", tsk, stack_pointer); |
867e359b CM |
233 | tsk = &corrupt; |
234 | } | |
235 | return tsk; | |
236 | } | |
237 | ||
238 | /* Take and return the pointer to the previous task, for schedule_tail(). */ | |
239 | struct task_struct *sim_notify_fork(struct task_struct *prev) | |
240 | { | |
241 | struct task_struct *tsk = current; | |
242 | __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_FORK_PARENT | | |
243 | (tsk->thread.creator_pid << _SIM_CONTROL_OPERATOR_BITS)); | |
244 | __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_FORK | | |
245 | (tsk->pid << _SIM_CONTROL_OPERATOR_BITS)); | |
246 | return prev; | |
247 | } | |
248 | ||
249 | int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs) | |
250 | { | |
251 | struct pt_regs *ptregs = task_pt_regs(tsk); | |
252 | elf_core_copy_regs(regs, ptregs); | |
253 | return 1; | |
254 | } | |
255 | ||
256 | #if CHIP_HAS_TILE_DMA() | |
257 | ||
258 | /* Allow user processes to access the DMA SPRs */ | |
259 | void grant_dma_mpls(void) | |
260 | { | |
a78c942d CM |
261 | #if CONFIG_KERNEL_PL == 2 |
262 | __insn_mtspr(SPR_MPL_DMA_CPL_SET_1, 1); | |
263 | __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_1, 1); | |
264 | #else | |
867e359b CM |
265 | __insn_mtspr(SPR_MPL_DMA_CPL_SET_0, 1); |
266 | __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_0, 1); | |
a78c942d | 267 | #endif |
867e359b CM |
268 | } |
269 | ||
270 | /* Forbid user processes from accessing the DMA SPRs */ | |
271 | void restrict_dma_mpls(void) | |
272 | { | |
a78c942d CM |
273 | #if CONFIG_KERNEL_PL == 2 |
274 | __insn_mtspr(SPR_MPL_DMA_CPL_SET_2, 1); | |
275 | __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_2, 1); | |
276 | #else | |
867e359b CM |
277 | __insn_mtspr(SPR_MPL_DMA_CPL_SET_1, 1); |
278 | __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_1, 1); | |
a78c942d | 279 | #endif |
867e359b CM |
280 | } |
281 | ||
282 | /* Pause the DMA engine, then save off its state registers. */ | |
283 | static void save_tile_dma_state(struct tile_dma_state *dma) | |
284 | { | |
285 | unsigned long state = __insn_mfspr(SPR_DMA_USER_STATUS); | |
286 | unsigned long post_suspend_state; | |
287 | ||
288 | /* If we're running, suspend the engine. */ | |
289 | if ((state & DMA_STATUS_MASK) == SPR_DMA_STATUS__RUNNING_MASK) | |
290 | __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__SUSPEND_MASK); | |
291 | ||
292 | /* | |
293 | * Wait for the engine to idle, then save regs. Note that we | |
294 | * want to record the "running" bit from before suspension, | |
295 | * and the "done" bit from after, so that we can properly | |
296 | * distinguish a case where the user suspended the engine from | |
297 | * the case where the kernel suspended as part of the context | |
298 | * swap. | |
299 | */ | |
300 | do { | |
301 | post_suspend_state = __insn_mfspr(SPR_DMA_USER_STATUS); | |
302 | } while (post_suspend_state & SPR_DMA_STATUS__BUSY_MASK); | |
303 | ||
304 | dma->src = __insn_mfspr(SPR_DMA_SRC_ADDR); | |
305 | dma->src_chunk = __insn_mfspr(SPR_DMA_SRC_CHUNK_ADDR); | |
306 | dma->dest = __insn_mfspr(SPR_DMA_DST_ADDR); | |
307 | dma->dest_chunk = __insn_mfspr(SPR_DMA_DST_CHUNK_ADDR); | |
308 | dma->strides = __insn_mfspr(SPR_DMA_STRIDE); | |
309 | dma->chunk_size = __insn_mfspr(SPR_DMA_CHUNK_SIZE); | |
310 | dma->byte = __insn_mfspr(SPR_DMA_BYTE); | |
311 | dma->status = (state & SPR_DMA_STATUS__RUNNING_MASK) | | |
312 | (post_suspend_state & SPR_DMA_STATUS__DONE_MASK); | |
313 | } | |
314 | ||
315 | /* Restart a DMA that was running before we were context-switched out. */ | |
316 | static void restore_tile_dma_state(struct thread_struct *t) | |
317 | { | |
318 | const struct tile_dma_state *dma = &t->tile_dma_state; | |
319 | ||
320 | /* | |
321 | * The only way to restore the done bit is to run a zero | |
322 | * length transaction. | |
323 | */ | |
324 | if ((dma->status & SPR_DMA_STATUS__DONE_MASK) && | |
325 | !(__insn_mfspr(SPR_DMA_USER_STATUS) & SPR_DMA_STATUS__DONE_MASK)) { | |
326 | __insn_mtspr(SPR_DMA_BYTE, 0); | |
327 | __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__REQUEST_MASK); | |
328 | while (__insn_mfspr(SPR_DMA_USER_STATUS) & | |
329 | SPR_DMA_STATUS__BUSY_MASK) | |
330 | ; | |
331 | } | |
332 | ||
333 | __insn_mtspr(SPR_DMA_SRC_ADDR, dma->src); | |
334 | __insn_mtspr(SPR_DMA_SRC_CHUNK_ADDR, dma->src_chunk); | |
335 | __insn_mtspr(SPR_DMA_DST_ADDR, dma->dest); | |
336 | __insn_mtspr(SPR_DMA_DST_CHUNK_ADDR, dma->dest_chunk); | |
337 | __insn_mtspr(SPR_DMA_STRIDE, dma->strides); | |
338 | __insn_mtspr(SPR_DMA_CHUNK_SIZE, dma->chunk_size); | |
339 | __insn_mtspr(SPR_DMA_BYTE, dma->byte); | |
340 | ||
341 | /* | |
342 | * Restart the engine if we were running and not done. | |
343 | * Clear a pending async DMA fault that we were waiting on return | |
344 | * to user space to execute, since we expect the DMA engine | |
345 | * to regenerate those faults for us now. Note that we don't | |
346 | * try to clear the TIF_ASYNC_TLB flag, since it's relatively | |
347 | * harmless if set, and it covers both DMA and the SN processor. | |
348 | */ | |
349 | if ((dma->status & DMA_STATUS_MASK) == SPR_DMA_STATUS__RUNNING_MASK) { | |
350 | t->dma_async_tlb.fault_num = 0; | |
351 | __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__REQUEST_MASK); | |
352 | } | |
353 | } | |
354 | ||
355 | #endif | |
356 | ||
357 | static void save_arch_state(struct thread_struct *t) | |
358 | { | |
359 | #if CHIP_HAS_SPLIT_INTR_MASK() | |
360 | t->interrupt_mask = __insn_mfspr(SPR_INTERRUPT_MASK_0_0) | | |
361 | ((u64)__insn_mfspr(SPR_INTERRUPT_MASK_0_1) << 32); | |
362 | #else | |
363 | t->interrupt_mask = __insn_mfspr(SPR_INTERRUPT_MASK_0); | |
364 | #endif | |
365 | t->ex_context[0] = __insn_mfspr(SPR_EX_CONTEXT_0_0); | |
366 | t->ex_context[1] = __insn_mfspr(SPR_EX_CONTEXT_0_1); | |
367 | t->system_save[0] = __insn_mfspr(SPR_SYSTEM_SAVE_0_0); | |
368 | t->system_save[1] = __insn_mfspr(SPR_SYSTEM_SAVE_0_1); | |
369 | t->system_save[2] = __insn_mfspr(SPR_SYSTEM_SAVE_0_2); | |
370 | t->system_save[3] = __insn_mfspr(SPR_SYSTEM_SAVE_0_3); | |
371 | t->intctrl_0 = __insn_mfspr(SPR_INTCTRL_0_STATUS); | |
372 | #if CHIP_HAS_PROC_STATUS_SPR() | |
373 | t->proc_status = __insn_mfspr(SPR_PROC_STATUS); | |
374 | #endif | |
a802fc68 CM |
375 | #if !CHIP_HAS_FIXED_INTVEC_BASE() |
376 | t->interrupt_vector_base = __insn_mfspr(SPR_INTERRUPT_VECTOR_BASE_0); | |
377 | #endif | |
378 | #if CHIP_HAS_TILE_RTF_HWM() | |
379 | t->tile_rtf_hwm = __insn_mfspr(SPR_TILE_RTF_HWM); | |
380 | #endif | |
381 | #if CHIP_HAS_DSTREAM_PF() | |
382 | t->dstream_pf = __insn_mfspr(SPR_DSTREAM_PF); | |
383 | #endif | |
867e359b CM |
384 | } |
385 | ||
386 | static void restore_arch_state(const struct thread_struct *t) | |
387 | { | |
388 | #if CHIP_HAS_SPLIT_INTR_MASK() | |
389 | __insn_mtspr(SPR_INTERRUPT_MASK_0_0, (u32) t->interrupt_mask); | |
390 | __insn_mtspr(SPR_INTERRUPT_MASK_0_1, t->interrupt_mask >> 32); | |
391 | #else | |
392 | __insn_mtspr(SPR_INTERRUPT_MASK_0, t->interrupt_mask); | |
393 | #endif | |
394 | __insn_mtspr(SPR_EX_CONTEXT_0_0, t->ex_context[0]); | |
395 | __insn_mtspr(SPR_EX_CONTEXT_0_1, t->ex_context[1]); | |
396 | __insn_mtspr(SPR_SYSTEM_SAVE_0_0, t->system_save[0]); | |
397 | __insn_mtspr(SPR_SYSTEM_SAVE_0_1, t->system_save[1]); | |
398 | __insn_mtspr(SPR_SYSTEM_SAVE_0_2, t->system_save[2]); | |
399 | __insn_mtspr(SPR_SYSTEM_SAVE_0_3, t->system_save[3]); | |
400 | __insn_mtspr(SPR_INTCTRL_0_STATUS, t->intctrl_0); | |
401 | #if CHIP_HAS_PROC_STATUS_SPR() | |
402 | __insn_mtspr(SPR_PROC_STATUS, t->proc_status); | |
403 | #endif | |
a802fc68 CM |
404 | #if !CHIP_HAS_FIXED_INTVEC_BASE() |
405 | __insn_mtspr(SPR_INTERRUPT_VECTOR_BASE_0, t->interrupt_vector_base); | |
406 | #endif | |
867e359b | 407 | #if CHIP_HAS_TILE_RTF_HWM() |
a802fc68 CM |
408 | __insn_mtspr(SPR_TILE_RTF_HWM, t->tile_rtf_hwm); |
409 | #endif | |
410 | #if CHIP_HAS_DSTREAM_PF() | |
411 | __insn_mtspr(SPR_DSTREAM_PF, t->dstream_pf); | |
867e359b CM |
412 | #endif |
413 | } | |
414 | ||
415 | ||
416 | void _prepare_arch_switch(struct task_struct *next) | |
417 | { | |
418 | #if CHIP_HAS_SN_PROC() | |
419 | int snctl; | |
420 | #endif | |
421 | #if CHIP_HAS_TILE_DMA() | |
422 | struct tile_dma_state *dma = ¤t->thread.tile_dma_state; | |
423 | if (dma->enabled) | |
424 | save_tile_dma_state(dma); | |
425 | #endif | |
426 | #if CHIP_HAS_SN_PROC() | |
427 | /* | |
428 | * Suspend the static network processor if it was running. | |
429 | * We do not suspend the fabric itself, just like we don't | |
430 | * try to suspend the UDN. | |
431 | */ | |
432 | snctl = __insn_mfspr(SPR_SNCTL); | |
433 | current->thread.sn_proc_running = | |
434 | (snctl & SPR_SNCTL__FRZPROC_MASK) == 0; | |
435 | if (current->thread.sn_proc_running) | |
436 | __insn_mtspr(SPR_SNCTL, snctl | SPR_SNCTL__FRZPROC_MASK); | |
437 | #endif | |
438 | } | |
439 | ||
440 | ||
867e359b CM |
441 | struct task_struct *__sched _switch_to(struct task_struct *prev, |
442 | struct task_struct *next) | |
443 | { | |
444 | /* DMA state is already saved; save off other arch state. */ | |
445 | save_arch_state(&prev->thread); | |
446 | ||
447 | #if CHIP_HAS_TILE_DMA() | |
448 | /* | |
449 | * Restore DMA in new task if desired. | |
450 | * Note that it is only safe to restart here since interrupts | |
451 | * are disabled, so we can't take any DMATLB miss or access | |
452 | * interrupts before we have finished switching stacks. | |
453 | */ | |
454 | if (next->thread.tile_dma_state.enabled) { | |
455 | restore_tile_dma_state(&next->thread); | |
456 | grant_dma_mpls(); | |
457 | } else { | |
458 | restrict_dma_mpls(); | |
459 | } | |
460 | #endif | |
461 | ||
462 | /* Restore other arch state. */ | |
463 | restore_arch_state(&next->thread); | |
464 | ||
465 | #if CHIP_HAS_SN_PROC() | |
466 | /* | |
467 | * Restart static network processor in the new process | |
468 | * if it was running before. | |
469 | */ | |
470 | if (next->thread.sn_proc_running) { | |
471 | int snctl = __insn_mfspr(SPR_SNCTL); | |
472 | __insn_mtspr(SPR_SNCTL, snctl & ~SPR_SNCTL__FRZPROC_MASK); | |
473 | } | |
474 | #endif | |
475 | ||
0707ad30 CM |
476 | #ifdef CONFIG_HARDWALL |
477 | /* Enable or disable access to the network registers appropriately. */ | |
b8ace083 | 478 | hardwall_switch_tasks(prev, next); |
0707ad30 | 479 | #endif |
867e359b CM |
480 | |
481 | /* | |
482 | * Switch kernel SP, PC, and callee-saved registers. | |
483 | * In the context of the new task, return the old task pointer | |
484 | * (i.e. the task that actually called __switch_to). | |
a78c942d | 485 | * Pass the value to use for SYSTEM_SAVE_K_0 when we reset our sp. |
867e359b CM |
486 | */ |
487 | return __switch_to(prev, next, next_current_ksp0(next)); | |
488 | } | |
489 | ||
313ce674 CM |
490 | /* |
491 | * This routine is called on return from interrupt if any of the | |
492 | * TIF_WORK_MASK flags are set in thread_info->flags. It is | |
493 | * entered with interrupts disabled so we don't miss an event | |
494 | * that modified the thread_info flags. If any flag is set, we | |
495 | * handle it and return, and the calling assembly code will | |
496 | * re-disable interrupts, reload the thread flags, and call back | |
497 | * if more flags need to be handled. | |
498 | * | |
499 | * We return whether we need to check the thread_info flags again | |
500 | * or not. Note that we don't clear TIF_SINGLESTEP here, so it's | |
501 | * important that it be tested last, and then claim that we don't | |
502 | * need to recheck the flags. | |
503 | */ | |
504 | int do_work_pending(struct pt_regs *regs, u32 thread_info_flags) | |
505 | { | |
fc327e26 CM |
506 | /* If we enter in kernel mode, do nothing and exit the caller loop. */ |
507 | if (!user_mode(regs)) | |
508 | return 0; | |
509 | ||
c19c6c95 CM |
510 | /* Enable interrupts; they are disabled again on return to caller. */ |
511 | local_irq_enable(); | |
512 | ||
313ce674 CM |
513 | if (thread_info_flags & _TIF_NEED_RESCHED) { |
514 | schedule(); | |
515 | return 1; | |
516 | } | |
517 | #if CHIP_HAS_TILE_DMA() || CHIP_HAS_SN_PROC() | |
518 | if (thread_info_flags & _TIF_ASYNC_TLB) { | |
519 | do_async_page_fault(regs); | |
520 | return 1; | |
521 | } | |
522 | #endif | |
523 | if (thread_info_flags & _TIF_SIGPENDING) { | |
524 | do_signal(regs); | |
525 | return 1; | |
526 | } | |
527 | if (thread_info_flags & _TIF_NOTIFY_RESUME) { | |
528 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
529 | tracehook_notify_resume(regs); | |
313ce674 CM |
530 | return 1; |
531 | } | |
532 | if (thread_info_flags & _TIF_SINGLESTEP) { | |
fc327e26 | 533 | single_step_once(regs); |
313ce674 CM |
534 | return 0; |
535 | } | |
536 | panic("work_pending: bad flags %#x\n", thread_info_flags); | |
537 | } | |
538 | ||
867e359b CM |
539 | unsigned long get_wchan(struct task_struct *p) |
540 | { | |
541 | struct KBacktraceIterator kbt; | |
542 | ||
543 | if (!p || p == current || p->state == TASK_RUNNING) | |
544 | return 0; | |
545 | ||
546 | for (KBacktraceIterator_init(&kbt, p, NULL); | |
547 | !KBacktraceIterator_end(&kbt); | |
548 | KBacktraceIterator_next(&kbt)) { | |
549 | if (!in_sched_functions(kbt.it.pc)) | |
550 | return kbt.it.pc; | |
551 | } | |
552 | ||
553 | return 0; | |
554 | } | |
555 | ||
867e359b CM |
556 | /* Flush thread state. */ |
557 | void flush_thread(void) | |
558 | { | |
559 | /* Nothing */ | |
560 | } | |
561 | ||
562 | /* | |
563 | * Free current thread data structures etc.. | |
564 | */ | |
565 | void exit_thread(void) | |
566 | { | |
567 | /* Nothing */ | |
568 | } | |
569 | ||
867e359b CM |
570 | void show_regs(struct pt_regs *regs) |
571 | { | |
572 | struct task_struct *tsk = validate_current(); | |
0707ad30 CM |
573 | int i; |
574 | ||
575 | pr_err("\n"); | |
a43cb95d | 576 | show_regs_print_info(KERN_ERR); |
0707ad30 CM |
577 | #ifdef __tilegx__ |
578 | for (i = 0; i < 51; i += 3) | |
579 | pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT" r%-2d: "REGFMT"\n", | |
580 | i, regs->regs[i], i+1, regs->regs[i+1], | |
581 | i+2, regs->regs[i+2]); | |
582 | pr_err(" r51: "REGFMT" r52: "REGFMT" tp : "REGFMT"\n", | |
583 | regs->regs[51], regs->regs[52], regs->tp); | |
584 | pr_err(" sp : "REGFMT" lr : "REGFMT"\n", regs->sp, regs->lr); | |
585 | #else | |
7040dea4 | 586 | for (i = 0; i < 52; i += 4) |
0707ad30 CM |
587 | pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT |
588 | " r%-2d: "REGFMT" r%-2d: "REGFMT"\n", | |
589 | i, regs->regs[i], i+1, regs->regs[i+1], | |
590 | i+2, regs->regs[i+2], i+3, regs->regs[i+3]); | |
591 | pr_err(" r52: "REGFMT" tp : "REGFMT" sp : "REGFMT" lr : "REGFMT"\n", | |
592 | regs->regs[52], regs->tp, regs->sp, regs->lr); | |
593 | #endif | |
594 | pr_err(" pc : "REGFMT" ex1: %ld faultnum: %ld\n", | |
867e359b CM |
595 | regs->pc, regs->ex1, regs->faultnum); |
596 | ||
597 | dump_stack_regs(regs); | |
598 | } |