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Commit 2319295d authored by Al Viro's avatar Al Viro Committed by Michal Simek
Browse files

microblaze: switch to generic kernel_thread() 



Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarMichal Simek <michal.simek@xilinx.com>
parent fd11ff73

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) */