diff options
Diffstat (limited to 'arch/mips/kernel/process.c')
| -rw-r--r-- | arch/mips/kernel/process.c | 318 |
1 files changed, 210 insertions, 108 deletions
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index f3d73e1831c..0a1ec0f3bef 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -7,17 +7,17 @@ * Copyright (C) 2005, 2006 by Ralf Baechle (ralf@linux-mips.org) * Copyright (C) 1999, 2000 Silicon Graphics, Inc. * Copyright (C) 2004 Thiemo Seufer + * Copyright (C) 2013 Imagination Technologies Ltd. */ #include <linux/errno.h> -#include <linux/module.h> #include <linux/sched.h> #include <linux/tick.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/stddef.h> #include <linux/unistd.h> +#include <linux/export.h> #include <linux/ptrace.h> -#include <linux/slab.h> #include <linux/mman.h> #include <linux/personality.h> #include <linux/sys.h> @@ -32,8 +32,8 @@ #include <asm/cpu.h> #include <asm/dsp.h> #include <asm/fpu.h> +#include <asm/msa.h> #include <asm/pgtable.h> -#include <asm/system.h> #include <asm/mipsregs.h> #include <asm/processor.h> #include <asm/uaccess.h> @@ -43,44 +43,17 @@ #include <asm/inst.h> #include <asm/stacktrace.h> -/* - * The idle thread. There's no useful work to be done, so just try to conserve - * power and have a low exit latency (ie sit in a loop waiting for somebody to - * say that they'd like to reschedule) - */ -void __noreturn cpu_idle(void) -{ - int cpu; - - /* CPU is going idle. */ - cpu = smp_processor_id(); - - /* endless idle loop with no priority at all */ - while (1) { - tick_nohz_stop_sched_tick(1); - while (!need_resched() && cpu_online(cpu)) { -#ifdef CONFIG_MIPS_MT_SMTC - extern void smtc_idle_loop_hook(void); - - smtc_idle_loop_hook(); -#endif - if (cpu_wait) - (*cpu_wait)(); - } #ifdef CONFIG_HOTPLUG_CPU - if (!cpu_online(cpu) && !cpu_isset(cpu, cpu_callin_map) && - (system_state == SYSTEM_RUNNING || - system_state == SYSTEM_BOOTING)) - play_dead(); -#endif - tick_nohz_restart_sched_tick(); - preempt_enable_no_resched(); - schedule(); - preempt_disable(); - } +void arch_cpu_idle_dead(void) +{ + /* What the heck is this check doing ? */ + if (!cpu_isset(smp_processor_id(), cpu_callin_map)) + play_dead(); } +#endif asmlinkage void ret_from_fork(void); +asmlinkage void ret_from_kernel_thread(void); void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp) { @@ -88,18 +61,15 @@ void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp) /* New thread loses kernel privileges. */ status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|ST0_FR|KU_MASK); -#ifdef CONFIG_64BIT - status |= test_thread_flag(TIF_32BIT_REGS) ? 0 : ST0_FR; -#endif status |= KU_USER; regs->cp0_status = status; clear_used_math(); clear_fpu_owner(); - if (cpu_has_dsp) - __init_dsp(); + init_dsp(); + clear_thread_flag(TIF_MSA_CTX_LIVE); + disable_msa(); regs->cp0_epc = pc; regs->regs[29] = sp; - current_thread_info()->addr_limit = USER_DS; } void exit_thread(void) @@ -111,10 +81,10 @@ void flush_thread(void) } int copy_thread(unsigned long clone_flags, unsigned long usp, - unsigned long unused, struct task_struct *p, struct pt_regs *regs) + unsigned long arg, struct task_struct *p) { struct thread_info *ti = task_thread_info(p); - struct pt_regs *childregs; + struct pt_regs *childregs, *regs = current_pt_regs(); unsigned long childksp; p->set_child_tid = p->clear_child_tid = NULL; @@ -122,7 +92,9 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, preempt_disable(); - if (is_fpu_owner()) + if (is_msa_enabled()) + save_msa(p); + else if (is_fpu_owner()) save_fp(p); if (cpu_has_dsp) @@ -134,20 +106,31 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, childregs = (struct pt_regs *) childksp - 1; /* Put the stack after the struct pt_regs. */ childksp = (unsigned long) childregs; - *childregs = *regs; - childregs->regs[7] = 0; /* Clear error flag */ - - childregs->regs[2] = 0; /* Child gets zero as return value */ - regs->regs[2] = p->pid; - - if (childregs->cp0_status & ST0_CU0) { - childregs->regs[28] = (unsigned long) ti; - childregs->regs[29] = childksp; + p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1); + if (unlikely(p->flags & PF_KTHREAD)) { + unsigned long status = p->thread.cp0_status; + memset(childregs, 0, sizeof(struct pt_regs)); ti->addr_limit = KERNEL_DS; - } else { - childregs->regs[29] = usp; - ti->addr_limit = USER_DS; + p->thread.reg16 = usp; /* fn */ + p->thread.reg17 = arg; + p->thread.reg29 = childksp; + p->thread.reg31 = (unsigned long) ret_from_kernel_thread; +#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX) + status = (status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) | + ((status & (ST0_KUC | ST0_IEC)) << 2); +#else + status |= ST0_EXL; +#endif + childregs->cp0_status = status; + return 0; } + *childregs = *regs; + childregs->regs[7] = 0; /* Clear error flag */ + childregs->regs[2] = 0; /* Child gets zero as return value */ + if (usp) + childregs->regs[29] = usp; + ti->addr_limit = USER_DS; + p->thread.reg29 = (unsigned long) childregs; p->thread.reg31 = (unsigned long) ret_from_fork; @@ -155,16 +138,8 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, * New tasks lose permission to use the fpu. This accelerates context * switching for most programs since they don't use the fpu. */ - p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1); childregs->cp0_status &= ~(ST0_CU2|ST0_CU1); -#ifdef CONFIG_MIPS_MT_SMTC - /* - * SMTC restores TCStatus after Status, and the CU bits - * are aliased there. - */ - childregs->cp0_tcstatus &= ~(ST0_CU2|ST0_CU1); -#endif clear_tsk_thread_flag(p, TIF_USEDFPU); #ifdef CONFIG_MIPS_MT_FPAFF @@ -180,7 +155,13 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, /* Fill in the fpu structure for a core dump.. */ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *r) { - memcpy(r, ¤t->thread.fpu, sizeof(current->thread.fpu)); + int i; + + for (i = 0; i < NUM_FPU_REGS; i++) + memcpy(&r[i], ¤t->thread.fpu.fpr[i], sizeof(*r)); + + memcpy(&r[NUM_FPU_REGS], ¤t->thread.fpu.fcr31, + sizeof(current->thread.fpu.fcr31)); return 1; } @@ -215,43 +196,23 @@ int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs) int dump_task_fpu(struct task_struct *t, elf_fpregset_t *fpr) { - memcpy(fpr, &t->thread.fpu, sizeof(current->thread.fpu)); + int i; - return 1; -} + for (i = 0; i < NUM_FPU_REGS; i++) + memcpy(&fpr[i], &t->thread.fpu.fpr[i], sizeof(*fpr)); -/* - * Create a kernel thread - */ -static void __noreturn kernel_thread_helper(void *arg, int (*fn)(void *)) -{ - do_exit(fn(arg)); -} - -long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) -{ - struct pt_regs regs; + memcpy(&fpr[NUM_FPU_REGS], &t->thread.fpu.fcr31, + sizeof(t->thread.fpu.fcr31)); - memset(®s, 0, sizeof(regs)); + return 1; +} - regs.regs[4] = (unsigned long) arg; - regs.regs[5] = (unsigned long) fn; - regs.cp0_epc = (unsigned long) kernel_thread_helper; - regs.cp0_status = read_c0_status(); -#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX) - regs.cp0_status = (regs.cp0_status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) | - ((regs.cp0_status & (ST0_KUC | ST0_IEC)) << 2); -#else - regs.cp0_status |= ST0_EXL; +#ifdef CONFIG_CC_STACKPROTECTOR +#include <linux/stackprotector.h> +unsigned long __stack_chk_guard __read_mostly; +EXPORT_SYMBOL(__stack_chk_guard); #endif - /* Ok, create the new process.. */ - return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); -} - -/* - * - */ struct mips_frame_info { void *func; unsigned long func_size; @@ -259,36 +220,122 @@ struct mips_frame_info { int pc_offset; }; +#define J_TARGET(pc,target) \ + (((unsigned long)(pc) & 0xf0000000) | ((target) << 2)) + static inline int is_ra_save_ins(union mips_instruction *ip) { +#ifdef CONFIG_CPU_MICROMIPS + union mips_instruction mmi; + + /* + * swsp ra,offset + * swm16 reglist,offset(sp) + * swm32 reglist,offset(sp) + * sw32 ra,offset(sp) + * jradiussp - NOT SUPPORTED + * + * microMIPS is way more fun... + */ + if (mm_insn_16bit(ip->halfword[0])) { + mmi.word = (ip->halfword[0] << 16); + return ((mmi.mm16_r5_format.opcode == mm_swsp16_op && + mmi.mm16_r5_format.rt == 31) || + (mmi.mm16_m_format.opcode == mm_pool16c_op && + mmi.mm16_m_format.func == mm_swm16_op)); + } + else { + mmi.halfword[0] = ip->halfword[1]; + mmi.halfword[1] = ip->halfword[0]; + return ((mmi.mm_m_format.opcode == mm_pool32b_op && + mmi.mm_m_format.rd > 9 && + mmi.mm_m_format.base == 29 && + mmi.mm_m_format.func == mm_swm32_func) || + (mmi.i_format.opcode == mm_sw32_op && + mmi.i_format.rs == 29 && + mmi.i_format.rt == 31)); + } +#else /* sw / sd $ra, offset($sp) */ return (ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) && ip->i_format.rs == 29 && ip->i_format.rt == 31; +#endif } -static inline int is_jal_jalr_jr_ins(union mips_instruction *ip) +static inline int is_jump_ins(union mips_instruction *ip) { +#ifdef CONFIG_CPU_MICROMIPS + /* + * jr16,jrc,jalr16,jalr16 + * jal + * jalr/jr,jalr.hb/jr.hb,jalrs,jalrs.hb + * jraddiusp - NOT SUPPORTED + * + * microMIPS is kind of more fun... + */ + union mips_instruction mmi; + + mmi.word = (ip->halfword[0] << 16); + + if ((mmi.mm16_r5_format.opcode == mm_pool16c_op && + (mmi.mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op) || + ip->j_format.opcode == mm_jal32_op) + return 1; + if (ip->r_format.opcode != mm_pool32a_op || + ip->r_format.func != mm_pool32axf_op) + return 0; + return (((ip->u_format.uimmediate >> 6) & mm_jalr_op) == mm_jalr_op); +#else + if (ip->j_format.opcode == j_op) + return 1; if (ip->j_format.opcode == jal_op) return 1; if (ip->r_format.opcode != spec_op) return 0; return ip->r_format.func == jalr_op || ip->r_format.func == jr_op; +#endif } static inline int is_sp_move_ins(union mips_instruction *ip) { +#ifdef CONFIG_CPU_MICROMIPS + /* + * addiusp -imm + * addius5 sp,-imm + * addiu32 sp,sp,-imm + * jradiussp - NOT SUPPORTED + * + * microMIPS is not more fun... + */ + if (mm_insn_16bit(ip->halfword[0])) { + union mips_instruction mmi; + + mmi.word = (ip->halfword[0] << 16); + return ((mmi.mm16_r3_format.opcode == mm_pool16d_op && + mmi.mm16_r3_format.simmediate && mm_addiusp_func) || + (mmi.mm16_r5_format.opcode == mm_pool16d_op && + mmi.mm16_r5_format.rt == 29)); + } + return (ip->mm_i_format.opcode == mm_addiu32_op && + ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29); +#else /* addiu/daddiu sp,sp,-imm */ if (ip->i_format.rs != 29 || ip->i_format.rt != 29) return 0; if (ip->i_format.opcode == addiu_op || ip->i_format.opcode == daddiu_op) return 1; +#endif return 0; } static int get_frame_info(struct mips_frame_info *info) { +#ifdef CONFIG_CPU_MICROMIPS + union mips_instruction *ip = (void *) (((char *) info->func) - 1); +#else union mips_instruction *ip = info->func; +#endif unsigned max_insns = info->func_size / sizeof(union mips_instruction); unsigned i; @@ -304,11 +351,30 @@ static int get_frame_info(struct mips_frame_info *info) for (i = 0; i < max_insns; i++, ip++) { - if (is_jal_jalr_jr_ins(ip)) + if (is_jump_ins(ip)) break; if (!info->frame_size) { if (is_sp_move_ins(ip)) + { +#ifdef CONFIG_CPU_MICROMIPS + if (mm_insn_16bit(ip->halfword[0])) + { + unsigned short tmp; + + if (ip->halfword[0] & mm_addiusp_func) + { + tmp = (((ip->halfword[0] >> 1) & 0x1ff) << 2); + info->frame_size = -(signed short)(tmp | ((tmp & 0x100) ? 0xfe00 : 0)); + } else { + tmp = (ip->halfword[0] >> 1); + info->frame_size = -(signed short)(tmp & 0xf); + } + ip = (void *) &ip->halfword[1]; + ip--; + } else +#endif info->frame_size = - ip->i_format.simmediate; + } continue; } if (info->pc_offset == -1 && is_ra_save_ins(ip)) { @@ -328,15 +394,42 @@ err: static struct mips_frame_info schedule_mfi __read_mostly; +#ifdef CONFIG_KALLSYMS +static unsigned long get___schedule_addr(void) +{ + return kallsyms_lookup_name("__schedule"); +} +#else +static unsigned long get___schedule_addr(void) +{ + union mips_instruction *ip = (void *)schedule; + int max_insns = 8; + int i; + + for (i = 0; i < max_insns; i++, ip++) { + if (ip->j_format.opcode == j_op) + return J_TARGET(ip, ip->j_format.target); + } + return 0; +} +#endif + static int __init frame_info_init(void) { unsigned long size = 0; #ifdef CONFIG_KALLSYMS unsigned long ofs; +#endif + unsigned long addr; + + addr = get___schedule_addr(); + if (!addr) + addr = (unsigned long)schedule; - kallsyms_lookup_size_offset((unsigned long)schedule, &size, &ofs); +#ifdef CONFIG_KALLSYMS + kallsyms_lookup_size_offset(addr, &size, &ofs); #endif - schedule_mfi.func = schedule; + schedule_mfi.func = (void *)addr; schedule_mfi.func_size = size; get_frame_info(&schedule_mfi); @@ -370,18 +463,18 @@ unsigned long thread_saved_pc(struct task_struct *tsk) #ifdef CONFIG_KALLSYMS -/* used by show_backtrace() */ -unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, - unsigned long pc, unsigned long *ra) +/* generic stack unwinding function */ +unsigned long notrace unwind_stack_by_address(unsigned long stack_page, + unsigned long *sp, + unsigned long pc, + unsigned long *ra) { - unsigned long stack_page; struct mips_frame_info info; unsigned long size, ofs; int leaf; extern void ret_from_irq(void); extern void ret_from_exception(void); - stack_page = (unsigned long)task_stack_page(task); if (!stack_page) return 0; @@ -407,7 +500,7 @@ unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, if (!kallsyms_lookup_size_offset(pc, &size, &ofs)) return 0; /* - * Return ra if an exception occured at the first instruction + * Return ra if an exception occurred at the first instruction */ if (unlikely(ofs == 0)) { pc = *ra; @@ -440,6 +533,15 @@ unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, *ra = 0; return __kernel_text_address(pc) ? pc : 0; } +EXPORT_SYMBOL(unwind_stack_by_address); + +/* used by show_backtrace() */ +unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, + unsigned long pc, unsigned long *ra) +{ + unsigned long stack_page = (unsigned long)task_stack_page(task); + return unwind_stack_by_address(stack_page, sp, pc, ra); +} #endif /* |