1 /*
2 * linux/arch/unicore32/kernel/process.c
3 *
4 * Code specific to PKUnity SoC and UniCore ISA
5 *
6 * Copyright (C) 2001-2010 GUAN Xue-tao
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12 #include <stdarg.h>
13
14 #include <linux/module.h>
15 #include <linux/sched.h>
16 #include <linux/kernel.h>
17 #include <linux/mm.h>
18 #include <linux/stddef.h>
19 #include <linux/unistd.h>
20 #include <linux/delay.h>
21 #include <linux/reboot.h>
22 #include <linux/interrupt.h>
23 #include <linux/kallsyms.h>
24 #include <linux/init.h>
25 #include <linux/cpu.h>
26 #include <linux/elfcore.h>
27 #include <linux/pm.h>
28 #include <linux/tick.h>
29 #include <linux/utsname.h>
30 #include <linux/uaccess.h>
31 #include <linux/random.h>
32 #include <linux/gpio.h>
33 #include <linux/stacktrace.h>
34
35 #include <asm/cacheflush.h>
36 #include <asm/processor.h>
37 #include <asm/system.h>
38 #include <asm/stacktrace.h>
39
40 #include "setup.h"
41
42 static const char * const processor_modes[] = {
43 "UK00", "UK01", "UK02", "UK03", "UK04", "UK05", "UK06", "UK07",
44 "UK08", "UK09", "UK0A", "UK0B", "UK0C", "UK0D", "UK0E", "UK0F",
45 "USER", "REAL", "INTR", "PRIV", "UK14", "UK15", "UK16", "ABRT",
46 "UK18", "UK19", "UK1A", "EXTN", "UK1C", "UK1D", "UK1E", "SUSR"
47 };
48
49 /*
50 * The idle thread, has rather strange semantics for calling pm_idle,
51 * but this is what x86 does and we need to do the same, so that
52 * things like cpuidle get called in the same way.
53 */
cpu_idle(void)54 void cpu_idle(void)
55 {
56 /* endless idle loop with no priority at all */
57 while (1) {
58 tick_nohz_stop_sched_tick(1);
59 while (!need_resched()) {
60 local_irq_disable();
61 stop_critical_timings();
62 cpu_do_idle();
63 local_irq_enable();
64 start_critical_timings();
65 }
66 tick_nohz_restart_sched_tick();
67 preempt_enable_no_resched();
68 schedule();
69 preempt_disable();
70 }
71 }
72
73 static char reboot_mode = 'h';
74
reboot_setup(char * str)75 int __init reboot_setup(char *str)
76 {
77 reboot_mode = str[0];
78 return 1;
79 }
80
81 __setup("reboot=", reboot_setup);
82
machine_halt(void)83 void machine_halt(void)
84 {
85 gpio_set_value(GPO_SOFT_OFF, 0);
86 }
87
88 /*
89 * Function pointers to optional machine specific functions
90 */
91 void (*pm_power_off)(void) = NULL;
92
machine_power_off(void)93 void machine_power_off(void)
94 {
95 if (pm_power_off)
96 pm_power_off();
97 machine_halt();
98 }
99
machine_restart(char * cmd)100 void machine_restart(char *cmd)
101 {
102 /* Disable interrupts first */
103 local_irq_disable();
104
105 /*
106 * Tell the mm system that we are going to reboot -
107 * we may need it to insert some 1:1 mappings so that
108 * soft boot works.
109 */
110 setup_mm_for_reboot(reboot_mode);
111
112 /* Clean and invalidate caches */
113 flush_cache_all();
114
115 /* Turn off caching */
116 cpu_proc_fin();
117
118 /* Push out any further dirty data, and ensure cache is empty */
119 flush_cache_all();
120
121 /*
122 * Now handle reboot code.
123 */
124 if (reboot_mode == 's') {
125 /* Jump into ROM at address 0xffff0000 */
126 cpu_reset(VECTORS_BASE);
127 } else {
128 writel(0x00002001, PM_PLLSYSCFG); /* cpu clk = 250M */
129 writel(0x00100800, PM_PLLDDRCFG); /* ddr clk = 44M */
130 writel(0x00002001, PM_PLLVGACFG); /* vga clk = 250M */
131
132 /* Use on-chip reset capability */
133 /* following instructions must be in one icache line */
134 __asm__ __volatile__(
135 " .align 5\n\t"
136 " stw %1, [%0]\n\t"
137 "201: ldw r0, [%0]\n\t"
138 " cmpsub.a r0, #0\n\t"
139 " bne 201b\n\t"
140 " stw %3, [%2]\n\t"
141 " nop; nop; nop\n\t"
142 /* prefetch 3 instructions at most */
143 :
144 : "r" (PM_PMCR),
145 "r" (PM_PMCR_CFBSYS | PM_PMCR_CFBDDR
146 | PM_PMCR_CFBVGA),
147 "r" (RESETC_SWRR),
148 "r" (RESETC_SWRR_SRB)
149 : "r0", "memory");
150 }
151
152 /*
153 * Whoops - the architecture was unable to reboot.
154 * Tell the user!
155 */
156 mdelay(1000);
157 printk(KERN_EMERG "Reboot failed -- System halted\n");
158 do { } while (1);
159 }
160
__show_regs(struct pt_regs * regs)161 void __show_regs(struct pt_regs *regs)
162 {
163 unsigned long flags;
164 char buf[64];
165
166 printk(KERN_DEFAULT "CPU: %d %s (%s %.*s)\n",
167 raw_smp_processor_id(), print_tainted(),
168 init_utsname()->release,
169 (int)strcspn(init_utsname()->version, " "),
170 init_utsname()->version);
171 print_symbol("PC is at %s\n", instruction_pointer(regs));
172 print_symbol("LR is at %s\n", regs->UCreg_lr);
173 printk(KERN_DEFAULT "pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
174 "sp : %08lx ip : %08lx fp : %08lx\n",
175 regs->UCreg_pc, regs->UCreg_lr, regs->UCreg_asr,
176 regs->UCreg_sp, regs->UCreg_ip, regs->UCreg_fp);
177 printk(KERN_DEFAULT "r26: %08lx r25: %08lx r24: %08lx\n",
178 regs->UCreg_26, regs->UCreg_25,
179 regs->UCreg_24);
180 printk(KERN_DEFAULT "r23: %08lx r22: %08lx r21: %08lx r20: %08lx\n",
181 regs->UCreg_23, regs->UCreg_22,
182 regs->UCreg_21, regs->UCreg_20);
183 printk(KERN_DEFAULT "r19: %08lx r18: %08lx r17: %08lx r16: %08lx\n",
184 regs->UCreg_19, regs->UCreg_18,
185 regs->UCreg_17, regs->UCreg_16);
186 printk(KERN_DEFAULT "r15: %08lx r14: %08lx r13: %08lx r12: %08lx\n",
187 regs->UCreg_15, regs->UCreg_14,
188 regs->UCreg_13, regs->UCreg_12);
189 printk(KERN_DEFAULT "r11: %08lx r10: %08lx r9 : %08lx r8 : %08lx\n",
190 regs->UCreg_11, regs->UCreg_10,
191 regs->UCreg_09, regs->UCreg_08);
192 printk(KERN_DEFAULT "r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
193 regs->UCreg_07, regs->UCreg_06,
194 regs->UCreg_05, regs->UCreg_04);
195 printk(KERN_DEFAULT "r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
196 regs->UCreg_03, regs->UCreg_02,
197 regs->UCreg_01, regs->UCreg_00);
198
199 flags = regs->UCreg_asr;
200 buf[0] = flags & PSR_S_BIT ? 'S' : 's';
201 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
202 buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
203 buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
204 buf[4] = '\0';
205
206 printk(KERN_DEFAULT "Flags: %s INTR o%s REAL o%s Mode %s Segment %s\n",
207 buf, interrupts_enabled(regs) ? "n" : "ff",
208 fast_interrupts_enabled(regs) ? "n" : "ff",
209 processor_modes[processor_mode(regs)],
210 segment_eq(get_fs(), get_ds()) ? "kernel" : "user");
211 {
212 unsigned int ctrl;
213
214 buf[0] = '\0';
215 {
216 unsigned int transbase;
217 asm("movc %0, p0.c2, #0\n"
218 : "=r" (transbase));
219 snprintf(buf, sizeof(buf), " Table: %08x", transbase);
220 }
221 asm("movc %0, p0.c1, #0\n" : "=r" (ctrl));
222
223 printk(KERN_DEFAULT "Control: %08x%s\n", ctrl, buf);
224 }
225 }
226
show_regs(struct pt_regs * regs)227 void show_regs(struct pt_regs *regs)
228 {
229 printk(KERN_DEFAULT "\n");
230 printk(KERN_DEFAULT "Pid: %d, comm: %20s\n",
231 task_pid_nr(current), current->comm);
232 __show_regs(regs);
233 __backtrace();
234 }
235
236 /*
237 * Free current thread data structures etc..
238 */
exit_thread(void)239 void exit_thread(void)
240 {
241 }
242
flush_thread(void)243 void flush_thread(void)
244 {
245 struct thread_info *thread = current_thread_info();
246 struct task_struct *tsk = current;
247
248 memset(thread->used_cp, 0, sizeof(thread->used_cp));
249 memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
250 #ifdef CONFIG_UNICORE_FPU_F64
251 memset(&thread->fpstate, 0, sizeof(struct fp_state));
252 #endif
253 }
254
release_thread(struct task_struct * dead_task)255 void release_thread(struct task_struct *dead_task)
256 {
257 }
258
259 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
260
261 int
copy_thread(unsigned long clone_flags,unsigned long stack_start,unsigned long stk_sz,struct task_struct * p,struct pt_regs * regs)262 copy_thread(unsigned long clone_flags, unsigned long stack_start,
263 unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
264 {
265 struct thread_info *thread = task_thread_info(p);
266 struct pt_regs *childregs = task_pt_regs(p);
267
268 *childregs = *regs;
269 childregs->UCreg_00 = 0;
270 childregs->UCreg_sp = stack_start;
271
272 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
273 thread->cpu_context.sp = (unsigned long)childregs;
274 thread->cpu_context.pc = (unsigned long)ret_from_fork;
275
276 if (clone_flags & CLONE_SETTLS)
277 childregs->UCreg_16 = regs->UCreg_03;
278
279 return 0;
280 }
281
282 /*
283 * Fill in the task's elfregs structure for a core dump.
284 */
dump_task_regs(struct task_struct * t,elf_gregset_t * elfregs)285 int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
286 {
287 elf_core_copy_regs(elfregs, task_pt_regs(t));
288 return 1;
289 }
290
291 /*
292 * fill in the fpe structure for a core dump...
293 */
dump_fpu(struct pt_regs * regs,elf_fpregset_t * fp)294 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fp)
295 {
296 struct thread_info *thread = current_thread_info();
297 int used_math = thread->used_cp[1] | thread->used_cp[2];
298
299 #ifdef CONFIG_UNICORE_FPU_F64
300 if (used_math)
301 memcpy(fp, &thread->fpstate, sizeof(*fp));
302 #endif
303 return used_math != 0;
304 }
305 EXPORT_SYMBOL(dump_fpu);
306
307 /*
308 * Shuffle the argument into the correct register before calling the
309 * thread function. r1 is the thread argument, r2 is the pointer to
310 * the thread function, and r3 points to the exit function.
311 */
312 asm(".pushsection .text\n"
313 " .align\n"
314 " .type kernel_thread_helper, #function\n"
315 "kernel_thread_helper:\n"
316 " mov.a asr, r7\n"
317 " mov r0, r4\n"
318 " mov lr, r6\n"
319 " mov pc, r5\n"
320 " .size kernel_thread_helper, . - kernel_thread_helper\n"
321 " .popsection");
322
323 /*
324 * Create a kernel thread.
325 */
kernel_thread(int (* fn)(void *),void * arg,unsigned long flags)326 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
327 {
328 struct pt_regs regs;
329
330 memset(®s, 0, sizeof(regs));
331
332 regs.UCreg_04 = (unsigned long)arg;
333 regs.UCreg_05 = (unsigned long)fn;
334 regs.UCreg_06 = (unsigned long)do_exit;
335 regs.UCreg_07 = PRIV_MODE;
336 regs.UCreg_pc = (unsigned long)kernel_thread_helper;
337 regs.UCreg_asr = regs.UCreg_07 | PSR_I_BIT;
338
339 return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL);
340 }
341 EXPORT_SYMBOL(kernel_thread);
342
get_wchan(struct task_struct * p)343 unsigned long get_wchan(struct task_struct *p)
344 {
345 struct stackframe frame;
346 int count = 0;
347 if (!p || p == current || p->state == TASK_RUNNING)
348 return 0;
349
350 frame.fp = thread_saved_fp(p);
351 frame.sp = thread_saved_sp(p);
352 frame.lr = 0; /* recovered from the stack */
353 frame.pc = thread_saved_pc(p);
354 do {
355 int ret = unwind_frame(&frame);
356 if (ret < 0)
357 return 0;
358 if (!in_sched_functions(frame.pc))
359 return frame.pc;
360 } while ((count++) < 16);
361 return 0;
362 }
363
arch_randomize_brk(struct mm_struct * mm)364 unsigned long arch_randomize_brk(struct mm_struct *mm)
365 {
366 unsigned long range_end = mm->brk + 0x02000000;
367 return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
368 }
369
370 /*
371 * The vectors page is always readable from user space for the
372 * atomic helpers and the signal restart code. Let's declare a mapping
373 * for it so it is visible through ptrace and /proc/<pid>/mem.
374 */
375
vectors_user_mapping(void)376 int vectors_user_mapping(void)
377 {
378 struct mm_struct *mm = current->mm;
379 return install_special_mapping(mm, 0xffff0000, PAGE_SIZE,
380 VM_READ | VM_EXEC |
381 VM_MAYREAD | VM_MAYEXEC |
382 VM_ALWAYSDUMP | VM_RESERVED,
383 NULL);
384 }
385
arch_vma_name(struct vm_area_struct * vma)386 const char *arch_vma_name(struct vm_area_struct *vma)
387 {
388 return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL;
389 }
390