microblaze: switch to generic kernel_thread() (2319295d) · Commits · 戴 / test

arch/microblaze/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

arch/microblaze/include/asm/processor.h

+1 −7

Original line number	Diff line number	Diff line
		@@ -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)
		{

arch/microblaze/kernel/entry-nommu.S

+8 −0

Original line number	Diff line number	Diff line
		@@ -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

arch/microblaze/kernel/entry.S

+9 −0

Original line number	Diff line number	Diff line
		@@ -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

arch/microblaze/kernel/process.c

+20 −51

Original line number	Diff line number	Diff line
		@@ -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;

		#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

		/* 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(&regs, 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,
		&regs, 0, NULL, NULL);
		}
		EXPORT_SYMBOL_GPL(kernel_thread);

		unsigned long get_wchan(struct task_struct *p)
		{
		/* TBD (used by procfs) */

Admin message