diff options
Diffstat (limited to 'arch/microblaze/kernel/process.c')
| -rw-r--r-- | arch/microblaze/kernel/process.c | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/arch/microblaze/kernel/process.c b/arch/microblaze/kernel/process.c new file mode 100644 index 00000000..883b9278 --- /dev/null +++ b/arch/microblaze/kernel/process.c @@ -0,0 +1,257 @@ +/* + * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu> + * Copyright (C) 2008-2009 PetaLogix + * Copyright (C) 2006 Atmark Techno, Inc. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/pm.h> +#include <linux/tick.h> +#include <linux/bitops.h> +#include <asm/pgalloc.h> +#include <asm/uaccess.h> /* for USER_DS macros */ +#include <asm/cacheflush.h> + +void show_regs(struct pt_regs *regs) +{ + printk(KERN_INFO " Registers dump: mode=%X\r\n", regs->pt_mode); + printk(KERN_INFO " r1=%08lX, r2=%08lX, r3=%08lX, r4=%08lX\n", + regs->r1, regs->r2, regs->r3, regs->r4); + printk(KERN_INFO " r5=%08lX, r6=%08lX, r7=%08lX, r8=%08lX\n", + regs->r5, regs->r6, regs->r7, regs->r8); + printk(KERN_INFO " r9=%08lX, r10=%08lX, r11=%08lX, r12=%08lX\n", + regs->r9, regs->r10, regs->r11, regs->r12); + printk(KERN_INFO " r13=%08lX, r14=%08lX, r15=%08lX, r16=%08lX\n", + regs->r13, regs->r14, regs->r15, regs->r16); + printk(KERN_INFO " r17=%08lX, r18=%08lX, r19=%08lX, r20=%08lX\n", + regs->r17, regs->r18, regs->r19, regs->r20); + printk(KERN_INFO " r21=%08lX, r22=%08lX, r23=%08lX, r24=%08lX\n", + regs->r21, regs->r22, regs->r23, regs->r24); + printk(KERN_INFO " r25=%08lX, r26=%08lX, r27=%08lX, r28=%08lX\n", + regs->r25, regs->r26, regs->r27, regs->r28); + printk(KERN_INFO " r29=%08lX, r30=%08lX, r31=%08lX, rPC=%08lX\n", + regs->r29, regs->r30, regs->r31, regs->pc); + printk(KERN_INFO " msr=%08lX, ear=%08lX, esr=%08lX, fsr=%08lX\n", + regs->msr, regs->ear, regs->esr, regs->fsr); +} + +void (*pm_idle)(void); +void (*pm_power_off)(void) = NULL; +EXPORT_SYMBOL(pm_power_off); + +static int hlt_counter = 1; + +void disable_hlt(void) +{ + hlt_counter++; +} +EXPORT_SYMBOL(disable_hlt); + +void enable_hlt(void) +{ + hlt_counter--; +} +EXPORT_SYMBOL(enable_hlt); + +static int __init nohlt_setup(char *__unused) +{ + hlt_counter = 1; + return 1; +} +__setup("nohlt", nohlt_setup); + +static int __init hlt_setup(char *__unused) +{ + hlt_counter = 0; + return 1; +} +__setup("hlt", hlt_setup); + +void default_idle(void) +{ + if (likely(hlt_counter)) { + local_irq_disable(); + stop_critical_timings(); + cpu_relax(); + start_critical_timings(); + local_irq_enable(); + } else { + clear_thread_flag(TIF_POLLING_NRFLAG); + smp_mb__after_clear_bit(); + local_irq_disable(); + while (!need_resched()) + cpu_sleep(); + local_irq_enable(); + set_thread_flag(TIF_POLLING_NRFLAG); + } +} + +void cpu_idle(void) +{ + set_thread_flag(TIF_POLLING_NRFLAG); + + /* endless idle loop with no priority at all */ + while (1) { + void (*idle)(void) = pm_idle; + + if (!idle) + idle = default_idle; + + tick_nohz_idle_enter(); + rcu_idle_enter(); + while (!need_resched()) + idle(); + rcu_idle_exit(); + tick_nohz_idle_exit(); + + schedule_preempt_disabled(); + check_pgt_cache(); + } +} + +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) +{ + struct pt_regs *childregs = task_pt_regs(p); + struct thread_info *ti = task_thread_info(p); + + *childregs = *regs; + if (user_mode(regs)) + childregs->r1 = usp; + else + childregs->r1 = ((unsigned long) ti) + THREAD_SIZE; + +#ifndef CONFIG_MMU + memset(&ti->cpu_context, 0, sizeof(struct cpu_context)); + ti->cpu_context.r1 = (unsigned long)childregs; + ti->cpu_context.msr = (unsigned long)childregs->msr; +#else + + /* if creating a kernel thread then update the current reg (we don't + * want to use the parent's value when restoring by POP_STATE) */ + if (kernel_mode(regs)) + /* save new current on stack to use POP_STATE */ + childregs->CURRENT_TASK = (unsigned long)p; + /* if returning to user then use the parent's value of this register */ + + /* if we're creating a new kernel thread then just zeroing all + * the registers. That's OK for a brand new thread.*/ + /* Pls. note that some of them will be restored in POP_STATE */ + if (kernel_mode(regs)) + memset(&ti->cpu_context, 0, sizeof(struct cpu_context)); + /* if this thread is created for fork/vfork/clone, then we want to + * restore all the parent's context */ + /* in addition to the registers which will be restored by POP_STATE */ + else { + ti->cpu_context = *(struct cpu_context *)regs; + childregs->msr |= MSR_UMS; + } + + /* FIXME STATE_SAVE_PT_OFFSET; */ + ti->cpu_context.r1 = (unsigned long)childregs; + /* we should consider the fact that childregs is a copy of the parent + * regs which were saved immediately after entering the kernel state + * before enabling VM. This MSR will be restored in switch_to and + * RETURN() and we want to have the right machine state there + * specifically this state must have INTs disabled before and enabled + * after performing rtbd + * compose the right MSR for RETURN(). It will work for switch_to also + * excepting for VM and UMS + * don't touch UMS , CARRY and cache bits + * right now MSR is a copy of parent one */ + childregs->msr |= MSR_BIP; + childregs->msr &= ~MSR_EIP; + childregs->msr |= MSR_IE; + childregs->msr &= ~MSR_VM; + childregs->msr |= MSR_VMS; + childregs->msr |= MSR_EE; /* exceptions will be enabled*/ + + ti->cpu_context.msr = (childregs->msr|MSR_VM); + ti->cpu_context.msr &= ~MSR_UMS; /* switch_to to kernel mode */ + ti->cpu_context.msr &= ~MSR_IE; +#endif + ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8; + + if (clone_flags & CLONE_SETTLS) + ; + + return 0; +} + +#ifndef CONFIG_MMU +/* + * Return saved PC of a blocked thread. + */ +unsigned long thread_saved_pc(struct task_struct *tsk) +{ + struct cpu_context *ctx = + &(((struct thread_info *)(tsk->stack))->cpu_context); + + /* Check whether the thread is blocked in resume() */ + if (in_sched_functions(ctx->r15)) + return (unsigned long)ctx->r15; + else + return ctx->r14; +} +#endif + +static void kernel_thread_helper(int (*fn)(void *), void *arg) +{ + fn(arg); + do_exit(-1); +} + +int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) +{ + struct pt_regs regs; + + memset(®s, 0, sizeof(regs)); + /* store them in non-volatile registers */ + regs.r5 = (unsigned long)fn; + regs.r6 = (unsigned long)arg; + local_save_flags(regs.msr); + regs.pc = (unsigned long)kernel_thread_helper; + regs.pt_mode = 1; + + return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, + ®s, 0, NULL, NULL); +} +EXPORT_SYMBOL_GPL(kernel_thread); + +unsigned long get_wchan(struct task_struct *p) +{ +/* TBD (used by procfs) */ + return 0; +} + +/* Set up a thread for executing a new program */ +void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp) +{ + regs->pc = pc; + regs->r1 = usp; + regs->pt_mode = 0; +#ifdef CONFIG_MMU + regs->msr |= MSR_UMS; +#endif +} + +#ifdef CONFIG_MMU +#include <linux/elfcore.h> +/* + * Set up a thread for executing a new program + */ +int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs) +{ + return 0; /* MicroBlaze has no separate FPU registers */ +} +#endif /* CONFIG_MMU */ |