1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* linux/arch/sparc/kernel/process.c |
3 | * |
4 | * Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net) |
5 | * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be) |
6 | */ |
7 | |
8 | /* |
9 | * This file handles the architecture-dependent parts of process handling.. |
10 | */ |
11 | #include <linux/elfcore.h> |
12 | #include <linux/errno.h> |
13 | #include <linux/module.h> |
14 | #include <linux/sched.h> |
15 | #include <linux/sched/debug.h> |
16 | #include <linux/sched/task.h> |
17 | #include <linux/sched/task_stack.h> |
18 | #include <linux/kernel.h> |
19 | #include <linux/mm.h> |
20 | #include <linux/stddef.h> |
21 | #include <linux/ptrace.h> |
22 | #include <linux/user.h> |
23 | #include <linux/smp.h> |
24 | #include <linux/reboot.h> |
25 | #include <linux/delay.h> |
26 | #include <linux/pm.h> |
27 | #include <linux/slab.h> |
28 | #include <linux/cpu.h> |
29 | |
30 | #include <asm/auxio.h> |
31 | #include <asm/oplib.h> |
32 | #include <linux/uaccess.h> |
33 | #include <asm/page.h> |
34 | #include <asm/delay.h> |
35 | #include <asm/processor.h> |
36 | #include <asm/psr.h> |
37 | #include <asm/elf.h> |
38 | #include <asm/prom.h> |
39 | #include <asm/unistd.h> |
40 | #include <asm/setup.h> |
41 | |
42 | #include "kernel.h" |
43 | |
44 | /* |
45 | * Power management idle function |
46 | * Set in pm platform drivers (apc.c and pmc.c) |
47 | */ |
48 | void (*sparc_idle)(void); |
49 | |
50 | /* |
51 | * Power-off handler instantiation for pm.h compliance |
52 | * This is done via auxio, but could be used as a fallback |
53 | * handler when auxio is not present-- unused for now... |
54 | */ |
55 | void (*pm_power_off)(void) = machine_power_off; |
56 | EXPORT_SYMBOL(pm_power_off); |
57 | |
58 | /* |
59 | * sysctl - toggle power-off restriction for serial console |
60 | * systems in machine_power_off() |
61 | */ |
62 | int scons_pwroff = 1; |
63 | |
64 | extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *); |
65 | |
66 | struct task_struct *last_task_used_math = NULL; |
67 | struct thread_info *current_set[NR_CPUS]; |
68 | |
69 | /* Idle loop support. */ |
70 | void arch_cpu_idle(void) |
71 | { |
72 | if (sparc_idle) |
73 | (*sparc_idle)(); |
74 | } |
75 | |
76 | /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */ |
77 | void machine_halt(void) |
78 | { |
79 | local_irq_enable(); |
80 | mdelay(8); |
81 | local_irq_disable(); |
82 | prom_halt(); |
83 | panic(fmt: "Halt failed!" ); |
84 | } |
85 | |
86 | void machine_restart(char * cmd) |
87 | { |
88 | char *p; |
89 | |
90 | local_irq_enable(); |
91 | mdelay(8); |
92 | local_irq_disable(); |
93 | |
94 | p = strchr (reboot_command, '\n'); |
95 | if (p) *p = 0; |
96 | if (cmd) |
97 | prom_reboot(cmd); |
98 | if (*reboot_command) |
99 | prom_reboot(reboot_command); |
100 | prom_feval ("reset" ); |
101 | panic(fmt: "Reboot failed!" ); |
102 | } |
103 | |
104 | void machine_power_off(void) |
105 | { |
106 | if (auxio_power_register && |
107 | (!of_node_is_type(np: of_console_device, type: "serial" ) || scons_pwroff)) { |
108 | u8 power_register = sbus_readb(auxio_power_register); |
109 | power_register |= AUXIO_POWER_OFF; |
110 | sbus_writeb(power_register, auxio_power_register); |
111 | } |
112 | |
113 | machine_halt(); |
114 | } |
115 | |
116 | void show_regs(struct pt_regs *r) |
117 | { |
118 | struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14]; |
119 | |
120 | show_regs_print_info(KERN_DEFAULT); |
121 | |
122 | printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n" , |
123 | r->psr, r->pc, r->npc, r->y, print_tainted()); |
124 | printk("PC: <%pS>\n" , (void *) r->pc); |
125 | printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n" , |
126 | r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3], |
127 | r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]); |
128 | printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n" , |
129 | r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11], |
130 | r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]); |
131 | printk("RPC: <%pS>\n" , (void *) r->u_regs[15]); |
132 | |
133 | printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n" , |
134 | rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3], |
135 | rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]); |
136 | printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n" , |
137 | rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3], |
138 | rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]); |
139 | } |
140 | |
141 | /* |
142 | * The show_stack() is external API which we do not use ourselves. |
143 | * The oops is printed in die_if_kernel. |
144 | */ |
145 | void show_stack(struct task_struct *tsk, unsigned long *_ksp, const char *loglvl) |
146 | { |
147 | unsigned long pc, fp; |
148 | unsigned long task_base; |
149 | struct reg_window32 *rw; |
150 | int count = 0; |
151 | |
152 | if (!tsk) |
153 | tsk = current; |
154 | |
155 | if (tsk == current && !_ksp) |
156 | __asm__ __volatile__("mov %%fp, %0" : "=r" (_ksp)); |
157 | |
158 | task_base = (unsigned long) task_stack_page(task: tsk); |
159 | fp = (unsigned long) _ksp; |
160 | do { |
161 | /* Bogus frame pointer? */ |
162 | if (fp < (task_base + sizeof(struct thread_info)) || |
163 | fp >= (task_base + (PAGE_SIZE << 1))) |
164 | break; |
165 | rw = (struct reg_window32 *) fp; |
166 | pc = rw->ins[7]; |
167 | printk("%s[%08lx : " , loglvl, pc); |
168 | printk("%s%pS ] " , loglvl, (void *) pc); |
169 | fp = rw->ins[6]; |
170 | } while (++count < 16); |
171 | printk("%s\n" , loglvl); |
172 | } |
173 | |
174 | /* |
175 | * Free current thread data structures etc.. |
176 | */ |
177 | void exit_thread(struct task_struct *tsk) |
178 | { |
179 | #ifndef CONFIG_SMP |
180 | if (last_task_used_math == tsk) { |
181 | #else |
182 | if (test_tsk_thread_flag(tsk, flag: TIF_USEDFPU)) { |
183 | #endif |
184 | /* Keep process from leaving FPU in a bogon state. */ |
185 | put_psr(get_psr() | PSR_EF); |
186 | fpsave(&tsk->thread.float_regs[0], &tsk->thread.fsr, |
187 | &tsk->thread.fpqueue[0], &tsk->thread.fpqdepth); |
188 | #ifndef CONFIG_SMP |
189 | last_task_used_math = NULL; |
190 | #else |
191 | clear_ti_thread_flag(task_thread_info(tsk), TIF_USEDFPU); |
192 | #endif |
193 | } |
194 | } |
195 | |
196 | void flush_thread(void) |
197 | { |
198 | current_thread_info()->w_saved = 0; |
199 | |
200 | #ifndef CONFIG_SMP |
201 | if(last_task_used_math == current) { |
202 | #else |
203 | if (test_thread_flag(TIF_USEDFPU)) { |
204 | #endif |
205 | /* Clean the fpu. */ |
206 | put_psr(get_psr() | PSR_EF); |
207 | fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, |
208 | ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); |
209 | #ifndef CONFIG_SMP |
210 | last_task_used_math = NULL; |
211 | #else |
212 | clear_thread_flag(TIF_USEDFPU); |
213 | #endif |
214 | } |
215 | } |
216 | |
217 | static inline struct sparc_stackf __user * |
218 | clone_stackframe(struct sparc_stackf __user *dst, |
219 | struct sparc_stackf __user *src) |
220 | { |
221 | unsigned long size, fp; |
222 | struct sparc_stackf *tmp; |
223 | struct sparc_stackf __user *sp; |
224 | |
225 | if (get_user(tmp, &src->fp)) |
226 | return NULL; |
227 | |
228 | fp = (unsigned long) tmp; |
229 | size = (fp - ((unsigned long) src)); |
230 | fp = (unsigned long) dst; |
231 | sp = (struct sparc_stackf __user *)(fp - size); |
232 | |
233 | /* do_fork() grabs the parent semaphore, we must release it |
234 | * temporarily so we can build the child clone stack frame |
235 | * without deadlocking. |
236 | */ |
237 | if (__copy_user(sp, src, size)) |
238 | sp = NULL; |
239 | else if (put_user(fp, &sp->fp)) |
240 | sp = NULL; |
241 | |
242 | return sp; |
243 | } |
244 | |
245 | /* Copy a Sparc thread. The fork() return value conventions |
246 | * under SunOS are nothing short of bletcherous: |
247 | * Parent --> %o0 == childs pid, %o1 == 0 |
248 | * Child --> %o0 == parents pid, %o1 == 1 |
249 | * |
250 | * NOTE: We have a separate fork kpsr/kwim because |
251 | * the parent could change these values between |
252 | * sys_fork invocation and when we reach here |
253 | * if the parent should sleep while trying to |
254 | * allocate the task_struct and kernel stack in |
255 | * do_fork(). |
256 | * XXX See comment above sys_vfork in sparc64. todo. |
257 | */ |
258 | extern void ret_from_fork(void); |
259 | extern void ret_from_kernel_thread(void); |
260 | |
261 | int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) |
262 | { |
263 | unsigned long clone_flags = args->flags; |
264 | unsigned long sp = args->stack; |
265 | unsigned long tls = args->tls; |
266 | struct thread_info *ti = task_thread_info(p); |
267 | struct pt_regs *childregs, *regs = current_pt_regs(); |
268 | char *new_stack; |
269 | |
270 | #ifndef CONFIG_SMP |
271 | if(last_task_used_math == current) { |
272 | #else |
273 | if (test_thread_flag(TIF_USEDFPU)) { |
274 | #endif |
275 | put_psr(get_psr() | PSR_EF); |
276 | fpsave(&p->thread.float_regs[0], &p->thread.fsr, |
277 | &p->thread.fpqueue[0], &p->thread.fpqdepth); |
278 | } |
279 | |
280 | /* |
281 | * p->thread_info new_stack childregs stack bottom |
282 | * ! ! ! ! |
283 | * V V (stk.fr.) V (pt_regs) V |
284 | * +----- - - - - - ------+===========+=============+ |
285 | */ |
286 | new_stack = task_stack_page(task: p) + THREAD_SIZE; |
287 | new_stack -= STACKFRAME_SZ + TRACEREG_SZ; |
288 | childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ); |
289 | |
290 | /* |
291 | * A new process must start with interrupts disabled, see schedule_tail() |
292 | * and finish_task_switch(). (If we do not do it and if a timer interrupt |
293 | * hits before we unlock and attempts to take the rq->lock, we deadlock.) |
294 | * |
295 | * Thus, kpsr |= PSR_PIL. |
296 | */ |
297 | ti->ksp = (unsigned long) new_stack; |
298 | p->thread.kregs = childregs; |
299 | |
300 | if (unlikely(args->fn)) { |
301 | extern int nwindows; |
302 | unsigned long psr; |
303 | memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ); |
304 | ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8); |
305 | childregs->u_regs[UREG_G1] = (unsigned long) args->fn; |
306 | childregs->u_regs[UREG_G2] = (unsigned long) args->fn_arg; |
307 | psr = childregs->psr = get_psr(); |
308 | ti->kpsr = psr | PSR_PIL; |
309 | ti->kwim = 1 << (((psr & PSR_CWP) + 1) % nwindows); |
310 | return 0; |
311 | } |
312 | memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ); |
313 | childregs->u_regs[UREG_FP] = sp; |
314 | ti->kpc = (((unsigned long) ret_from_fork) - 0x8); |
315 | ti->kpsr = current->thread.fork_kpsr | PSR_PIL; |
316 | ti->kwim = current->thread.fork_kwim; |
317 | |
318 | if (sp != regs->u_regs[UREG_FP]) { |
319 | struct sparc_stackf __user *childstack; |
320 | struct sparc_stackf __user *parentstack; |
321 | |
322 | /* |
323 | * This is a clone() call with supplied user stack. |
324 | * Set some valid stack frames to give to the child. |
325 | */ |
326 | childstack = (struct sparc_stackf __user *) |
327 | (sp & ~0xfUL); |
328 | parentstack = (struct sparc_stackf __user *) |
329 | regs->u_regs[UREG_FP]; |
330 | |
331 | #if 0 |
332 | printk("clone: parent stack:\n" ); |
333 | show_stackframe(parentstack); |
334 | #endif |
335 | |
336 | childstack = clone_stackframe(dst: childstack, src: parentstack); |
337 | if (!childstack) |
338 | return -EFAULT; |
339 | |
340 | #if 0 |
341 | printk("clone: child stack:\n" ); |
342 | show_stackframe(childstack); |
343 | #endif |
344 | |
345 | childregs->u_regs[UREG_FP] = (unsigned long)childstack; |
346 | } |
347 | |
348 | #ifdef CONFIG_SMP |
349 | /* FPU must be disabled on SMP. */ |
350 | childregs->psr &= ~PSR_EF; |
351 | clear_tsk_thread_flag(p, TIF_USEDFPU); |
352 | #endif |
353 | |
354 | /* Set the return value for the child. */ |
355 | childregs->u_regs[UREG_I0] = current->pid; |
356 | childregs->u_regs[UREG_I1] = 1; |
357 | |
358 | /* Set the return value for the parent. */ |
359 | regs->u_regs[UREG_I1] = 0; |
360 | |
361 | if (clone_flags & CLONE_SETTLS) |
362 | childregs->u_regs[UREG_G7] = tls; |
363 | |
364 | return 0; |
365 | } |
366 | |
367 | unsigned long __get_wchan(struct task_struct *task) |
368 | { |
369 | unsigned long pc, fp, bias = 0; |
370 | unsigned long task_base = (unsigned long) task; |
371 | unsigned long ret = 0; |
372 | struct reg_window32 *rw; |
373 | int count = 0; |
374 | |
375 | fp = task_thread_info(task)->ksp + bias; |
376 | do { |
377 | /* Bogus frame pointer? */ |
378 | if (fp < (task_base + sizeof(struct thread_info)) || |
379 | fp >= (task_base + (2 * PAGE_SIZE))) |
380 | break; |
381 | rw = (struct reg_window32 *) fp; |
382 | pc = rw->ins[7]; |
383 | if (!in_sched_functions(addr: pc)) { |
384 | ret = pc; |
385 | goto out; |
386 | } |
387 | fp = rw->ins[6] + bias; |
388 | } while (++count < 16); |
389 | |
390 | out: |
391 | return ret; |
392 | } |
393 | |
394 | |