diff options
Diffstat (limited to 'arch/microblaze/kernel/process.c')
| -rw-r--r-- | arch/microblaze/kernel/process.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/arch/microblaze/kernel/process.c b/arch/microblaze/kernel/process.c index 07d4fa339eda..00b12c6d5326 100644 --- a/arch/microblaze/kernel/process.c +++ b/arch/microblaze/kernel/process.c @@ -126,9 +126,54 @@ int copy_thread(unsigned long clone_flags, unsigned long 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 - STATE_SAVE_ARG_SPACE; + /* 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 */ +#endif ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8; if (clone_flags & CLONE_SETTLS) @@ -137,6 +182,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, return 0; } +#ifndef CONFIG_MMU /* * Return saved PC of a blocked thread. */ @@ -151,6 +197,7 @@ unsigned long thread_saved_pc(struct task_struct *tsk) else return ctx->r14; } +#endif static void kernel_thread_helper(int (*fn)(void *), void *arg) { @@ -173,6 +220,7 @@ int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) 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) { @@ -188,3 +236,14 @@ void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp) regs->r1 = usp; regs->pt_mode = 0; } + +#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 */ |