| 1 | /* |
| 2 | * arch/sh/kernel/process.c |
| 3 | * |
| 4 | * This file handles the architecture-dependent parts of process handling.. |
| 5 | * |
| 6 | * Copyright (C) 1995 Linus Torvalds |
| 7 | * |
| 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 |
| 11 | * |
| 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 |
| 14 | * for more details. |
| 15 | */ |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/mm.h> |
| 18 | #include <linux/slab.h> |
| 19 | #include <linux/elfcore.h> |
| 20 | #include <linux/kallsyms.h> |
| 21 | #include <linux/fs.h> |
| 22 | #include <linux/ftrace.h> |
| 23 | #include <linux/hw_breakpoint.h> |
| 24 | #include <linux/prefetch.h> |
| 25 | #include <linux/stackprotector.h> |
| 26 | #include <asm/uaccess.h> |
| 27 | #include <asm/mmu_context.h> |
| 28 | #include <asm/fpu.h> |
| 29 | #include <asm/syscalls.h> |
| 30 | #include <asm/switch_to.h> |
| 31 | |
| 32 | void show_regs(struct pt_regs * regs) |
| 33 | { |
| 34 | printk("\n"); |
| 35 | show_regs_print_info(KERN_DEFAULT); |
| 36 | |
| 37 | print_symbol("PC is at %s\n", instruction_pointer(regs)); |
| 38 | print_symbol("PR is at %s\n", regs->pr); |
| 39 | |
| 40 | printk("PC : %08lx SP : %08lx SR : %08lx ", |
| 41 | regs->pc, regs->regs[15], regs->sr); |
| 42 | #ifdef CONFIG_MMU |
| 43 | printk("TEA : %08x\n", __raw_readl(MMU_TEA)); |
| 44 | #else |
| 45 | printk("\n"); |
| 46 | #endif |
| 47 | |
| 48 | printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n", |
| 49 | regs->regs[0],regs->regs[1], |
| 50 | regs->regs[2],regs->regs[3]); |
| 51 | printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n", |
| 52 | regs->regs[4],regs->regs[5], |
| 53 | regs->regs[6],regs->regs[7]); |
| 54 | printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n", |
| 55 | regs->regs[8],regs->regs[9], |
| 56 | regs->regs[10],regs->regs[11]); |
| 57 | printk("R12 : %08lx R13 : %08lx R14 : %08lx\n", |
| 58 | regs->regs[12],regs->regs[13], |
| 59 | regs->regs[14]); |
| 60 | printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n", |
| 61 | regs->mach, regs->macl, regs->gbr, regs->pr); |
| 62 | |
| 63 | show_trace(NULL, (unsigned long *)regs->regs[15], regs); |
| 64 | show_code(regs); |
| 65 | } |
| 66 | |
| 67 | void start_thread(struct pt_regs *regs, unsigned long new_pc, |
| 68 | unsigned long new_sp) |
| 69 | { |
| 70 | regs->pr = 0; |
| 71 | regs->sr = SR_FD; |
| 72 | regs->pc = new_pc; |
| 73 | regs->regs[15] = new_sp; |
| 74 | |
| 75 | free_thread_xstate(current); |
| 76 | } |
| 77 | EXPORT_SYMBOL(start_thread); |
| 78 | |
| 79 | /* |
| 80 | * Free current thread data structures etc.. |
| 81 | */ |
| 82 | void exit_thread(void) |
| 83 | { |
| 84 | } |
| 85 | |
| 86 | void flush_thread(void) |
| 87 | { |
| 88 | struct task_struct *tsk = current; |
| 89 | |
| 90 | flush_ptrace_hw_breakpoint(tsk); |
| 91 | |
| 92 | #if defined(CONFIG_SH_FPU) |
| 93 | /* Forget lazy FPU state */ |
| 94 | clear_fpu(tsk, task_pt_regs(tsk)); |
| 95 | clear_used_math(); |
| 96 | #endif |
| 97 | } |
| 98 | |
| 99 | void release_thread(struct task_struct *dead_task) |
| 100 | { |
| 101 | /* do nothing */ |
| 102 | } |
| 103 | |
| 104 | /* Fill in the fpu structure for a core dump.. */ |
| 105 | int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) |
| 106 | { |
| 107 | int fpvalid = 0; |
| 108 | |
| 109 | #if defined(CONFIG_SH_FPU) |
| 110 | struct task_struct *tsk = current; |
| 111 | |
| 112 | fpvalid = !!tsk_used_math(tsk); |
| 113 | if (fpvalid) |
| 114 | fpvalid = !fpregs_get(tsk, NULL, 0, |
| 115 | sizeof(struct user_fpu_struct), |
| 116 | fpu, NULL); |
| 117 | #endif |
| 118 | |
| 119 | return fpvalid; |
| 120 | } |
| 121 | EXPORT_SYMBOL(dump_fpu); |
| 122 | |
| 123 | asmlinkage void ret_from_fork(void); |
| 124 | asmlinkage void ret_from_kernel_thread(void); |
| 125 | |
| 126 | int copy_thread(unsigned long clone_flags, unsigned long usp, |
| 127 | unsigned long arg, struct task_struct *p) |
| 128 | { |
| 129 | struct thread_info *ti = task_thread_info(p); |
| 130 | struct pt_regs *childregs; |
| 131 | |
| 132 | #if defined(CONFIG_SH_DSP) |
| 133 | struct task_struct *tsk = current; |
| 134 | |
| 135 | if (is_dsp_enabled(tsk)) { |
| 136 | /* We can use the __save_dsp or just copy the struct: |
| 137 | * __save_dsp(p); |
| 138 | * p->thread.dsp_status.status |= SR_DSP |
| 139 | */ |
| 140 | p->thread.dsp_status = tsk->thread.dsp_status; |
| 141 | } |
| 142 | #endif |
| 143 | |
| 144 | memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps)); |
| 145 | |
| 146 | childregs = task_pt_regs(p); |
| 147 | p->thread.sp = (unsigned long) childregs; |
| 148 | if (unlikely(p->flags & PF_KTHREAD)) { |
| 149 | memset(childregs, 0, sizeof(struct pt_regs)); |
| 150 | p->thread.pc = (unsigned long) ret_from_kernel_thread; |
| 151 | childregs->regs[4] = arg; |
| 152 | childregs->regs[5] = usp; |
| 153 | childregs->sr = SR_MD; |
| 154 | #if defined(CONFIG_SH_FPU) |
| 155 | childregs->sr |= SR_FD; |
| 156 | #endif |
| 157 | ti->addr_limit = KERNEL_DS; |
| 158 | ti->status &= ~TS_USEDFPU; |
| 159 | p->fpu_counter = 0; |
| 160 | return 0; |
| 161 | } |
| 162 | *childregs = *current_pt_regs(); |
| 163 | |
| 164 | if (usp) |
| 165 | childregs->regs[15] = usp; |
| 166 | ti->addr_limit = USER_DS; |
| 167 | |
| 168 | if (clone_flags & CLONE_SETTLS) |
| 169 | childregs->gbr = childregs->regs[0]; |
| 170 | |
| 171 | childregs->regs[0] = 0; /* Set return value for child */ |
| 172 | p->thread.pc = (unsigned long) ret_from_fork; |
| 173 | return 0; |
| 174 | } |
| 175 | |
| 176 | /* |
| 177 | * switch_to(x,y) should switch tasks from x to y. |
| 178 | * |
| 179 | */ |
| 180 | __notrace_funcgraph struct task_struct * |
| 181 | __switch_to(struct task_struct *prev, struct task_struct *next) |
| 182 | { |
| 183 | struct thread_struct *next_t = &next->thread; |
| 184 | |
| 185 | #if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP) |
| 186 | __stack_chk_guard = next->stack_canary; |
| 187 | #endif |
| 188 | |
| 189 | unlazy_fpu(prev, task_pt_regs(prev)); |
| 190 | |
| 191 | /* we're going to use this soon, after a few expensive things */ |
| 192 | if (next->fpu_counter > 5) |
| 193 | prefetch(next_t->xstate); |
| 194 | |
| 195 | #ifdef CONFIG_MMU |
| 196 | /* |
| 197 | * Restore the kernel mode register |
| 198 | * k7 (r7_bank1) |
| 199 | */ |
| 200 | asm volatile("ldc %0, r7_bank" |
| 201 | : /* no output */ |
| 202 | : "r" (task_thread_info(next))); |
| 203 | #endif |
| 204 | |
| 205 | /* |
| 206 | * If the task has used fpu the last 5 timeslices, just do a full |
| 207 | * restore of the math state immediately to avoid the trap; the |
| 208 | * chances of needing FPU soon are obviously high now |
| 209 | */ |
| 210 | if (next->fpu_counter > 5) |
| 211 | __fpu_state_restore(); |
| 212 | |
| 213 | return prev; |
| 214 | } |
| 215 | |
| 216 | unsigned long get_wchan(struct task_struct *p) |
| 217 | { |
| 218 | unsigned long pc; |
| 219 | |
| 220 | if (!p || p == current || p->state == TASK_RUNNING) |
| 221 | return 0; |
| 222 | |
| 223 | /* |
| 224 | * The same comment as on the Alpha applies here, too ... |
| 225 | */ |
| 226 | pc = thread_saved_pc(p); |
| 227 | |
| 228 | #ifdef CONFIG_FRAME_POINTER |
| 229 | if (in_sched_functions(pc)) { |
| 230 | unsigned long schedule_frame = (unsigned long)p->thread.sp; |
| 231 | return ((unsigned long *)schedule_frame)[21]; |
| 232 | } |
| 233 | #endif |
| 234 | |
| 235 | return pc; |
| 236 | } |