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
41static 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
48void arch_cpu_idle(void)
49{
50	cpu_do_idle();
51	local_irq_enable();
52}
53
54void machine_halt(void)
55{
56	gpio_set_value(GPO_SOFT_OFF, 0);
57}
58
59/*
60 * Function pointers to optional machine specific functions
61 */
62void (*pm_power_off)(void) = NULL;
63EXPORT_SYMBOL(pm_power_off);
64
65void machine_power_off(void)
66{
67	if (pm_power_off)
68		pm_power_off();
69	machine_halt();
70}
71
72void 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
133void __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
195void 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
204/*
205 * Free current thread data structures etc..
206 */
207void exit_thread(void)
208{
209}
210
211void flush_thread(void)
212{
213	struct thread_info *thread = current_thread_info();
214	struct task_struct *tsk = current;
215
216	memset(thread->used_cp, 0, sizeof(thread->used_cp));
217	memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
218#ifdef CONFIG_UNICORE_FPU_F64
219	memset(&thread->fpstate, 0, sizeof(struct fp_state));
220#endif
221}
222
223void release_thread(struct task_struct *dead_task)
224{
225}
226
227asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
228asmlinkage void ret_from_kernel_thread(void) __asm__("ret_from_kernel_thread");
229
230int
231copy_thread(unsigned long clone_flags, unsigned long stack_start,
232	    unsigned long stk_sz, struct task_struct *p)
233{
234	struct thread_info *thread = task_thread_info(p);
235	struct pt_regs *childregs = task_pt_regs(p);
236
237	memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
238	thread->cpu_context.sp = (unsigned long)childregs;
239	if (unlikely(p->flags & PF_KTHREAD)) {
240		thread->cpu_context.pc = (unsigned long)ret_from_kernel_thread;
241		thread->cpu_context.r4 = stack_start;
242		thread->cpu_context.r5 = stk_sz;
243		memset(childregs, 0, sizeof(struct pt_regs));
244	} else {
245		thread->cpu_context.pc = (unsigned long)ret_from_fork;
246		*childregs = *current_pt_regs();
247		childregs->UCreg_00 = 0;
248		if (stack_start)
249			childregs->UCreg_sp = stack_start;
250
251		if (clone_flags & CLONE_SETTLS)
252			childregs->UCreg_16 = childregs->UCreg_03;
253	}
254	return 0;
255}
256
257/*
258 * Fill in the task's elfregs structure for a core dump.
259 */
260int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
261{
262	elf_core_copy_regs(elfregs, task_pt_regs(t));
263	return 1;
264}
265
266/*
267 * fill in the fpe structure for a core dump...
268 */
269int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fp)
270{
271	struct thread_info *thread = current_thread_info();
272	int used_math = thread->used_cp[1] | thread->used_cp[2];
273
274#ifdef CONFIG_UNICORE_FPU_F64
275	if (used_math)
276		memcpy(fp, &thread->fpstate, sizeof(*fp));
277#endif
278	return used_math != 0;
279}
280EXPORT_SYMBOL(dump_fpu);
281
282unsigned long get_wchan(struct task_struct *p)
283{
284	struct stackframe frame;
285	int count = 0;
286	if (!p || p == current || p->state == TASK_RUNNING)
287		return 0;
288
289	frame.fp = thread_saved_fp(p);
290	frame.sp = thread_saved_sp(p);
291	frame.lr = 0;			/* recovered from the stack */
292	frame.pc = thread_saved_pc(p);
293	do {
294		int ret = unwind_frame(&frame);
295		if (ret < 0)
296			return 0;
297		if (!in_sched_functions(frame.pc))
298			return frame.pc;
299	} while ((count++) < 16);
300	return 0;
301}
302
303unsigned long arch_randomize_brk(struct mm_struct *mm)
304{
305	unsigned long range_end = mm->brk + 0x02000000;
306	return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
307}
308
309/*
310 * The vectors page is always readable from user space for the
311 * atomic helpers and the signal restart code.  Let's declare a mapping
312 * for it so it is visible through ptrace and /proc/<pid>/mem.
313 */
314
315int vectors_user_mapping(void)
316{
317	struct mm_struct *mm = current->mm;
318	return install_special_mapping(mm, 0xffff0000, PAGE_SIZE,
319				       VM_READ | VM_EXEC |
320				       VM_MAYREAD | VM_MAYEXEC |
321				       VM_DONTEXPAND | VM_DONTDUMP,
322				       NULL);
323}
324
325const char *arch_vma_name(struct vm_area_struct *vma)
326{
327	return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL;
328}
329