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/sched/debug.h>
17 #include <linux/sched/task.h>
18 #include <linux/sched/task_stack.h>
19 #include <linux/kernel.h>
20 #include <linux/mm.h>
21 #include <linux/stddef.h>
22 #include <linux/unistd.h>
23 #include <linux/delay.h>
24 #include <linux/reboot.h>
25 #include <linux/interrupt.h>
26 #include <linux/init.h>
27 #include <linux/cpu.h>
28 #include <linux/elfcore.h>
29 #include <linux/pm.h>
30 #include <linux/tick.h>
31 #include <linux/utsname.h>
32 #include <linux/uaccess.h>
33 #include <linux/random.h>
34 #include <linux/gpio.h>
35 #include <linux/stacktrace.h>
36
37 #include <asm/cacheflush.h>
38 #include <asm/processor.h>
39 #include <asm/stacktrace.h>
40
41 #include "setup.h"
42
43 static const char * const processor_modes[] = {
44 "UK00", "UK01", "UK02", "UK03", "UK04", "UK05", "UK06", "UK07",
45 "UK08", "UK09", "UK0A", "UK0B", "UK0C", "UK0D", "UK0E", "UK0F",
46 "USER", "REAL", "INTR", "PRIV", "UK14", "UK15", "UK16", "ABRT",
47 "UK18", "UK19", "UK1A", "EXTN", "UK1C", "UK1D", "UK1E", "SUSR"
48 };
49
arch_cpu_idle(void)50 void arch_cpu_idle(void)
51 {
52 cpu_do_idle();
53 local_irq_enable();
54 }
55
machine_halt(void)56 void machine_halt(void)
57 {
58 gpio_set_value(GPO_SOFT_OFF, 0);
59 }
60
61 /*
62 * Function pointers to optional machine specific functions
63 */
64 void (*pm_power_off)(void) = NULL;
65 EXPORT_SYMBOL(pm_power_off);
66
machine_power_off(void)67 void machine_power_off(void)
68 {
69 if (pm_power_off)
70 pm_power_off();
71 machine_halt();
72 }
73
machine_restart(char * cmd)74 void machine_restart(char *cmd)
75 {
76 /* Disable interrupts first */
77 local_irq_disable();
78
79 /*
80 * Tell the mm system that we are going to reboot -
81 * we may need it to insert some 1:1 mappings so that
82 * soft boot works.
83 */
84 setup_mm_for_reboot();
85
86 /* Clean and invalidate caches */
87 flush_cache_all();
88
89 /* Turn off caching */
90 cpu_proc_fin();
91
92 /* Push out any further dirty data, and ensure cache is empty */
93 flush_cache_all();
94
95 /*
96 * Now handle reboot code.
97 */
98 if (reboot_mode == REBOOT_SOFT) {
99 /* Jump into ROM at address 0xffff0000 */
100 cpu_reset(VECTORS_BASE);
101 } else {
102 writel(0x00002001, PM_PLLSYSCFG); /* cpu clk = 250M */
103 writel(0x00100800, PM_PLLDDRCFG); /* ddr clk = 44M */
104 writel(0x00002001, PM_PLLVGACFG); /* vga clk = 250M */
105
106 /* Use on-chip reset capability */
107 /* following instructions must be in one icache line */
108 __asm__ __volatile__(
109 " .align 5\n\t"
110 " stw %1, [%0]\n\t"
111 "201: ldw r0, [%0]\n\t"
112 " cmpsub.a r0, #0\n\t"
113 " bne 201b\n\t"
114 " stw %3, [%2]\n\t"
115 " nop; nop; nop\n\t"
116 /* prefetch 3 instructions at most */
117 :
118 : "r" (PM_PMCR),
119 "r" (PM_PMCR_CFBSYS | PM_PMCR_CFBDDR
120 | PM_PMCR_CFBVGA),
121 "r" (RESETC_SWRR),
122 "r" (RESETC_SWRR_SRB)
123 : "r0", "memory");
124 }
125
126 /*
127 * Whoops - the architecture was unable to reboot.
128 * Tell the user!
129 */
130 mdelay(1000);
131 printk(KERN_EMERG "Reboot failed -- System halted\n");
132 do { } while (1);
133 }
134
__show_regs(struct pt_regs * regs)135 void __show_regs(struct pt_regs *regs)
136 {
137 unsigned long flags;
138 char buf[64];
139
140 show_regs_print_info(KERN_DEFAULT);
141 printk("PC is at %pS\n", (void *)instruction_pointer(regs));
142 printk("LR is at %pS\n", (void *)regs->UCreg_lr);
143 printk(KERN_DEFAULT "pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
144 "sp : %08lx ip : %08lx fp : %08lx\n",
145 regs->UCreg_pc, regs->UCreg_lr, regs->UCreg_asr,
146 regs->UCreg_sp, regs->UCreg_ip, regs->UCreg_fp);
147 printk(KERN_DEFAULT "r26: %08lx r25: %08lx r24: %08lx\n",
148 regs->UCreg_26, regs->UCreg_25,
149 regs->UCreg_24);
150 printk(KERN_DEFAULT "r23: %08lx r22: %08lx r21: %08lx r20: %08lx\n",
151 regs->UCreg_23, regs->UCreg_22,
152 regs->UCreg_21, regs->UCreg_20);
153 printk(KERN_DEFAULT "r19: %08lx r18: %08lx r17: %08lx r16: %08lx\n",
154 regs->UCreg_19, regs->UCreg_18,
155 regs->UCreg_17, regs->UCreg_16);
156 printk(KERN_DEFAULT "r15: %08lx r14: %08lx r13: %08lx r12: %08lx\n",
157 regs->UCreg_15, regs->UCreg_14,
158 regs->UCreg_13, regs->UCreg_12);
159 printk(KERN_DEFAULT "r11: %08lx r10: %08lx r9 : %08lx r8 : %08lx\n",
160 regs->UCreg_11, regs->UCreg_10,
161 regs->UCreg_09, regs->UCreg_08);
162 printk(KERN_DEFAULT "r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
163 regs->UCreg_07, regs->UCreg_06,
164 regs->UCreg_05, regs->UCreg_04);
165 printk(KERN_DEFAULT "r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
166 regs->UCreg_03, regs->UCreg_02,
167 regs->UCreg_01, regs->UCreg_00);
168
169 flags = regs->UCreg_asr;
170 buf[0] = flags & PSR_S_BIT ? 'S' : 's';
171 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
172 buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
173 buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
174 buf[4] = '\0';
175
176 printk(KERN_DEFAULT "Flags: %s INTR o%s REAL o%s Mode %s Segment %s\n",
177 buf, interrupts_enabled(regs) ? "n" : "ff",
178 fast_interrupts_enabled(regs) ? "n" : "ff",
179 processor_modes[processor_mode(regs)],
180 uaccess_kernel() ? "kernel" : "user");
181 {
182 unsigned int ctrl;
183
184 buf[0] = '\0';
185 {
186 unsigned int transbase;
187 asm("movc %0, p0.c2, #0\n"
188 : "=r" (transbase));
189 snprintf(buf, sizeof(buf), " Table: %08x", transbase);
190 }
191 asm("movc %0, p0.c1, #0\n" : "=r" (ctrl));
192
193 printk(KERN_DEFAULT "Control: %08x%s\n", ctrl, buf);
194 }
195 }
196
show_regs(struct pt_regs * regs)197 void show_regs(struct pt_regs *regs)
198 {
199 printk(KERN_DEFAULT "\n");
200 printk(KERN_DEFAULT "Pid: %d, comm: %20s\n",
201 task_pid_nr(current), current->comm);
202 __show_regs(regs);
203 __backtrace();
204 }
205
flush_thread(void)206 void flush_thread(void)
207 {
208 struct thread_info *thread = current_thread_info();
209 struct task_struct *tsk = current;
210
211 memset(thread->used_cp, 0, sizeof(thread->used_cp));
212 memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
213 #ifdef CONFIG_UNICORE_FPU_F64
214 memset(&thread->fpstate, 0, sizeof(struct fp_state));
215 #endif
216 }
217
release_thread(struct task_struct * dead_task)218 void release_thread(struct task_struct *dead_task)
219 {
220 }
221
222 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
223 asmlinkage void ret_from_kernel_thread(void) __asm__("ret_from_kernel_thread");
224
225 int
copy_thread(unsigned long clone_flags,unsigned long stack_start,unsigned long stk_sz,struct task_struct * p)226 copy_thread(unsigned long clone_flags, unsigned long stack_start,
227 unsigned long stk_sz, struct task_struct *p)
228 {
229 struct thread_info *thread = task_thread_info(p);
230 struct pt_regs *childregs = task_pt_regs(p);
231
232 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
233 thread->cpu_context.sp = (unsigned long)childregs;
234 if (unlikely(p->flags & PF_KTHREAD)) {
235 thread->cpu_context.pc = (unsigned long)ret_from_kernel_thread;
236 thread->cpu_context.r4 = stack_start;
237 thread->cpu_context.r5 = stk_sz;
238 memset(childregs, 0, sizeof(struct pt_regs));
239 } else {
240 thread->cpu_context.pc = (unsigned long)ret_from_fork;
241 *childregs = *current_pt_regs();
242 childregs->UCreg_00 = 0;
243 if (stack_start)
244 childregs->UCreg_sp = stack_start;
245
246 if (clone_flags & CLONE_SETTLS)
247 childregs->UCreg_16 = childregs->UCreg_03;
248 }
249 return 0;
250 }
251
252 /*
253 * Fill in the task's elfregs structure for a core dump.
254 */
dump_task_regs(struct task_struct * t,elf_gregset_t * elfregs)255 int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
256 {
257 elf_core_copy_regs(elfregs, task_pt_regs(t));
258 return 1;
259 }
260
261 /*
262 * fill in the fpe structure for a core dump...
263 */
dump_fpu(struct pt_regs * regs,elf_fpregset_t * fp)264 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fp)
265 {
266 struct thread_info *thread = current_thread_info();
267 int used_math = thread->used_cp[1] | thread->used_cp[2];
268
269 #ifdef CONFIG_UNICORE_FPU_F64
270 if (used_math)
271 memcpy(fp, &thread->fpstate, sizeof(*fp));
272 #endif
273 return used_math != 0;
274 }
275 EXPORT_SYMBOL(dump_fpu);
276
get_wchan(struct task_struct * p)277 unsigned long get_wchan(struct task_struct *p)
278 {
279 struct stackframe frame;
280 int count = 0;
281 if (!p || p == current || p->state == TASK_RUNNING)
282 return 0;
283
284 frame.fp = thread_saved_fp(p);
285 frame.sp = thread_saved_sp(p);
286 frame.lr = 0; /* recovered from the stack */
287 frame.pc = thread_saved_pc(p);
288 do {
289 int ret = unwind_frame(&frame);
290 if (ret < 0)
291 return 0;
292 if (!in_sched_functions(frame.pc))
293 return frame.pc;
294 } while ((count++) < 16);
295 return 0;
296 }
297
arch_randomize_brk(struct mm_struct * mm)298 unsigned long arch_randomize_brk(struct mm_struct *mm)
299 {
300 return randomize_page(mm->brk, 0x02000000);
301 }
302
303 /*
304 * The vectors page is always readable from user space for the
305 * atomic helpers and the signal restart code. Let's declare a mapping
306 * for it so it is visible through ptrace and /proc/<pid>/mem.
307 */
308
vectors_user_mapping(void)309 int vectors_user_mapping(void)
310 {
311 struct mm_struct *mm = current->mm;
312 return install_special_mapping(mm, 0xffff0000, PAGE_SIZE,
313 VM_READ | VM_EXEC |
314 VM_MAYREAD | VM_MAYEXEC |
315 VM_DONTEXPAND | VM_DONTDUMP,
316 NULL);
317 }
318
arch_vma_name(struct vm_area_struct * vma)319 const char *arch_vma_name(struct vm_area_struct *vma)
320 {
321 return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL;
322 }
323
