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