2 * arch/sh/kernel/process.c
4 * This file handles the architecture-dependent parts of process handling..
6 * Copyright (C) 1995 Linus Torvalds
8 * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
9 * Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC
10 * Copyright (C) 2002 - 2008 Paul Mundt
12 * This file is subject to the terms and conditions of the GNU General Public
13 * License. See the file "COPYING" in the main directory of this archive
16 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/elfcore.h>
20 #include <linux/kallsyms.h>
22 #include <linux/ftrace.h>
23 #include <linux/hw_breakpoint.h>
24 #include <linux/prefetch.h>
25 #include <asm/uaccess.h>
26 #include <asm/mmu_context.h>
28 #include <asm/syscalls.h>
29 #include <asm/switch_to.h>
31 void show_regs(struct pt_regs * regs)
34 printk("Pid : %d, Comm: \t\t%s\n", task_pid_nr(current), current->comm);
35 printk("CPU : %d \t\t%s (%s %.*s)\n\n",
36 smp_processor_id(), print_tainted(), init_utsname()->release,
37 (int)strcspn(init_utsname()->version, " "),
38 init_utsname()->version);
40 print_symbol("PC is at %s\n", instruction_pointer(regs));
41 print_symbol("PR is at %s\n", regs->pr);
43 printk("PC : %08lx SP : %08lx SR : %08lx ",
44 regs->pc, regs->regs[15], regs->sr);
46 printk("TEA : %08x\n", __raw_readl(MMU_TEA));
51 printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
52 regs->regs[0],regs->regs[1],
53 regs->regs[2],regs->regs[3]);
54 printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
55 regs->regs[4],regs->regs[5],
56 regs->regs[6],regs->regs[7]);
57 printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
58 regs->regs[8],regs->regs[9],
59 regs->regs[10],regs->regs[11]);
60 printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
61 regs->regs[12],regs->regs[13],
63 printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
64 regs->mach, regs->macl, regs->gbr, regs->pr);
66 show_trace(NULL, (unsigned long *)regs->regs[15], regs);
71 * Create a kernel thread
73 __noreturn void kernel_thread_helper(void *arg, int (*fn)(void *))
78 /* Don't use this in BL=1(cli). Or else, CPU resets! */
79 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
84 memset(®s, 0, sizeof(regs));
85 regs.regs[4] = (unsigned long)arg;
86 regs.regs[5] = (unsigned long)fn;
88 regs.pc = (unsigned long)kernel_thread_helper;
90 #if defined(CONFIG_SH_FPU)
94 /* Ok, create the new process.. */
95 pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
96 ®s, 0, NULL, NULL);
100 EXPORT_SYMBOL(kernel_thread);
102 void start_thread(struct pt_regs *regs, unsigned long new_pc,
103 unsigned long new_sp)
108 regs->regs[15] = new_sp;
110 free_thread_xstate(current);
112 EXPORT_SYMBOL(start_thread);
115 * Free current thread data structures etc..
117 void exit_thread(void)
121 void flush_thread(void)
123 struct task_struct *tsk = current;
125 flush_ptrace_hw_breakpoint(tsk);
127 #if defined(CONFIG_SH_FPU)
128 /* Forget lazy FPU state */
129 clear_fpu(tsk, task_pt_regs(tsk));
134 void release_thread(struct task_struct *dead_task)
139 /* Fill in the fpu structure for a core dump.. */
140 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
144 #if defined(CONFIG_SH_FPU)
145 struct task_struct *tsk = current;
147 fpvalid = !!tsk_used_math(tsk);
149 fpvalid = !fpregs_get(tsk, NULL, 0,
150 sizeof(struct user_fpu_struct),
156 EXPORT_SYMBOL(dump_fpu);
158 asmlinkage void ret_from_fork(void);
160 int copy_thread(unsigned long clone_flags, unsigned long usp,
161 unsigned long unused,
162 struct task_struct *p, struct pt_regs *regs)
164 struct thread_info *ti = task_thread_info(p);
165 struct pt_regs *childregs;
167 #if defined(CONFIG_SH_DSP)
168 struct task_struct *tsk = current;
170 if (is_dsp_enabled(tsk)) {
171 /* We can use the __save_dsp or just copy the struct:
173 * p->thread.dsp_status.status |= SR_DSP
175 p->thread.dsp_status = tsk->thread.dsp_status;
179 childregs = task_pt_regs(p);
182 if (user_mode(regs)) {
183 childregs->regs[15] = usp;
184 ti->addr_limit = USER_DS;
186 childregs->regs[15] = (unsigned long)childregs;
187 ti->addr_limit = KERNEL_DS;
188 ti->status &= ~TS_USEDFPU;
192 if (clone_flags & CLONE_SETTLS)
193 childregs->gbr = childregs->regs[0];
195 childregs->regs[0] = 0; /* Set return value for child */
197 p->thread.sp = (unsigned long) childregs;
198 p->thread.pc = (unsigned long) ret_from_fork;
200 memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
206 * switch_to(x,y) should switch tasks from x to y.
209 __notrace_funcgraph struct task_struct *
210 __switch_to(struct task_struct *prev, struct task_struct *next)
212 struct thread_struct *next_t = &next->thread;
214 unlazy_fpu(prev, task_pt_regs(prev));
216 /* we're going to use this soon, after a few expensive things */
217 if (next->fpu_counter > 5)
218 prefetch(next_t->xstate);
222 * Restore the kernel mode register
225 asm volatile("ldc %0, r7_bank"
227 : "r" (task_thread_info(next)));
231 * If the task has used fpu the last 5 timeslices, just do a full
232 * restore of the math state immediately to avoid the trap; the
233 * chances of needing FPU soon are obviously high now
235 if (next->fpu_counter > 5)
236 __fpu_state_restore();
241 asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
242 unsigned long r6, unsigned long r7,
243 struct pt_regs __regs)
246 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
247 return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL);
249 /* fork almost works, enough to trick you into looking elsewhere :-( */
254 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
255 unsigned long parent_tidptr,
256 unsigned long child_tidptr,
257 struct pt_regs __regs)
259 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
261 newsp = regs->regs[15];
262 return do_fork(clone_flags, newsp, regs, 0,
263 (int __user *)parent_tidptr,
264 (int __user *)child_tidptr);
268 * This is trivial, and on the face of it looks like it
269 * could equally well be done in user mode.
271 * Not so, for quite unobvious reasons - register pressure.
272 * In user mode vfork() cannot have a stack frame, and if
273 * done by calling the "clone()" system call directly, you
274 * do not have enough call-clobbered registers to hold all
275 * the information you need.
277 asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
278 unsigned long r6, unsigned long r7,
279 struct pt_regs __regs)
281 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
282 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs,
287 * sys_execve() executes a new program.
289 asmlinkage int sys_execve(const char __user *ufilename,
290 const char __user *const __user *uargv,
291 const char __user *const __user *uenvp,
292 unsigned long r7, struct pt_regs __regs)
294 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
298 filename = getname(ufilename);
299 error = PTR_ERR(filename);
300 if (IS_ERR(filename))
303 error = do_execve(filename, uargv, uenvp, regs);
309 unsigned long get_wchan(struct task_struct *p)
313 if (!p || p == current || p->state == TASK_RUNNING)
317 * The same comment as on the Alpha applies here, too ...
319 pc = thread_saved_pc(p);
321 #ifdef CONFIG_FRAME_POINTER
322 if (in_sched_functions(pc)) {
323 unsigned long schedule_frame = (unsigned long)p->thread.sp;
324 return ((unsigned long *)schedule_frame)[21];