From 2319295dd8dbd076afa136bffb797ef726b605a0 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 6 Oct 2012 13:52:37 -0400 Subject: [PATCH] microblaze: switch to generic kernel_thread() Signed-off-by: Al Viro Signed-off-by: Michal Simek --- arch/microblaze/Kconfig | 1 + arch/microblaze/include/asm/processor.h | 8 +--- arch/microblaze/kernel/entry-nommu.S | 8 ++++ arch/microblaze/kernel/entry.S | 9 +++++ arch/microblaze/kernel/process.c | 71 ++++++++++----------------------- 5 files changed, 39 insertions(+), 58 deletions(-) diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig index 4cba743..3b8df66 100644 --- a/arch/microblaze/Kconfig +++ b/arch/microblaze/Kconfig @@ -26,6 +26,7 @@ config MICROBLAZE select GENERIC_ATOMIC64 select GENERIC_CLOCKEVENTS select MODULES_USE_ELF_RELA + select GENERIC_KERNEL_THREAD config SWAP def_bool n diff --git a/arch/microblaze/include/asm/processor.h b/arch/microblaze/include/asm/processor.h index af2bb96..0759153 100644 --- a/arch/microblaze/include/asm/processor.h +++ b/arch/microblaze/include/asm/processor.h @@ -31,6 +31,7 @@ extern const struct seq_operations cpuinfo_op; void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp); extern void ret_from_fork(void); +extern void ret_from_kernel_thread(void); # endif /* __ASSEMBLY__ */ @@ -78,11 +79,6 @@ extern unsigned long thread_saved_pc(struct task_struct *t); extern unsigned long get_wchan(struct task_struct *p); -/* - * create a kernel thread without removing it from tasklists - */ -extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); - # define KSTK_EIP(tsk) (0) # define KSTK_ESP(tsk) (0) @@ -131,8 +127,6 @@ extern inline void release_thread(struct task_struct *dead_task) { } -extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); - /* Free current thread data structures etc. */ static inline void exit_thread(void) { diff --git a/arch/microblaze/kernel/entry-nommu.S b/arch/microblaze/kernel/entry-nommu.S index 75c3ea1..c47e92c 100644 --- a/arch/microblaze/kernel/entry-nommu.S +++ b/arch/microblaze/kernel/entry-nommu.S @@ -474,6 +474,14 @@ ENTRY(ret_from_fork) brid ret_to_user nop +ENTRY(ret_from_kernel_thread) + brlid r15, schedule_tail + addk r5, r0, r3 + brald r15, r20 + addk r5, r0, r19 + brid sys_exit /* won't be returning... */ + addk r5, r0, r0 + work_pending: enable_irq diff --git a/arch/microblaze/kernel/entry.S b/arch/microblaze/kernel/entry.S index 1cf702a..be76d13 100644 --- a/arch/microblaze/kernel/entry.S +++ b/arch/microblaze/kernel/entry.S @@ -484,6 +484,15 @@ C_ENTRY(ret_from_fork): brid ret_from_trap; /* Do normal trap return */ add r3, r0, r0; /* Child's fork call should return 0. */ +C_ENTRY(ret_from_kernel_thread): + bralid r15, schedule_tail; /* ...which is schedule_tail's arg */ + add r5, r3, r0; /* switch_thread returns the prev task */ + /* ( in the delay slot ) */ + brald r15, r20 /* fn was left in r20 */ + addk r5, r0, r19 /* ... and argument - in r19 */ + brid sys_exit /* won't be returning... */ + addk r5, r0, r0 + C_ENTRY(sys_vfork): brid microblaze_vfork /* Do real work (tail-call) */ addik r5, r1, 0 diff --git a/arch/microblaze/kernel/process.c b/arch/microblaze/kernel/process.c index 1944e00..cbf8bb9 100644 --- a/arch/microblaze/kernel/process.c +++ b/arch/microblaze/kernel/process.c @@ -119,46 +119,38 @@ void flush_thread(void) } int copy_thread(unsigned long clone_flags, unsigned long usp, - unsigned long unused, + unsigned long arg, struct task_struct *p, struct pt_regs *regs) { struct pt_regs *childregs = task_pt_regs(p); struct thread_info *ti = task_thread_info(p); + if (unlikely(p->flags & PF_KTHREAD)) { + /* if we're creating a new kernel thread then just zeroing all + * the registers. That's OK for a brand new thread.*/ + memset(childregs, 0, sizeof(struct pt_regs)); + memset(&ti->cpu_context, 0, sizeof(struct cpu_context)); + ti->cpu_context.r1 = (unsigned long)childregs; + ti->cpu_context.r20 = (unsigned long)usp; /* fn */ + ti->cpu_context.r19 = (unsigned long)arg; + childregs->pt_mode = 1; + local_save_flags(childregs->msr); +#ifdef CONFIG_MMU + ti->cpu_context.msr = childregs->msr & ~MSR_IE; +#endif + ti->cpu_context.r15 = (unsigned long)ret_from_kernel_thread - 8; + return 0; + } *childregs = *regs; - if (user_mode(regs)) - childregs->r1 = usp; - else - childregs->r1 = ((unsigned long) ti) + THREAD_SIZE; + childregs->r1 = usp; -#ifndef CONFIG_MMU memset(&ti->cpu_context, 0, sizeof(struct cpu_context)); ti->cpu_context.r1 = (unsigned long)childregs; +#ifndef CONFIG_MMU ti->cpu_context.msr = (unsigned long)childregs->msr; #else + childregs->msr |= MSR_UMS; - /* 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 @@ -209,29 +201,6 @@ unsigned long thread_saved_pc(struct task_struct *tsk) } #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) */ -- 2.7.4