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Commit a44e060f authored by Al Viro's avatar Al Viro
Browse files

parisc: switch to generic kernel_thread() 



Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent ddffeb8c

arch/parisc/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ config PARISC 
	select GENERIC_STRNCPY_FROM_USER

	select HAVE_MOD_ARCH_SPECIFIC

	select MODULES_USE_ELF_RELA

	select GENERIC_KERNEL_THREAD



	help

	  The PA-RISC microprocessor is designed by Hewlett-Packard and used

arch/parisc/kernel/entry.S

+1 −52
Original line number Diff line number Diff line
@@ -707,60 +707,10 @@ ENTRY(end_fault_vector) 
	.import		handle_interruption,code

	.import		do_cpu_irq_mask,code



	/*

	 * r26 = function to be called

	 * r25 = argument to pass in

	 * r24 = flags for do_fork()

	 *

	 * Kernel threads don't ever return, so they don't need

	 * a true register context. We just save away the arguments

	 * for copy_thread/ret_ to properly set up the child.

	 */



#define CLONE_VM 0x100	/* Must agree with <linux/sched.h> */

#define CLONE_UNTRACED 0x00800000



	.import do_fork

ENTRY(__kernel_thread)

	STREG	%r2, -RP_OFFSET(%r30)



	copy	%r30, %r1

	ldo	PT_SZ_ALGN(%r30),%r30

#ifdef CONFIG_64BIT

	/* Yo, function pointers in wide mode are little structs... -PB */

	ldd	24(%r26), %r2

	STREG	%r2, PT_GR27(%r1)	/* Store childs %dp */

	ldd	16(%r26), %r26



	STREG	%r22, PT_GR22(%r1)	/* save r22 (arg5) */

	copy	%r0, %r22		/* user_tid */

#endif

	STREG	%r26, PT_GR26(%r1)  /* Store function & argument for child */

	STREG	%r25, PT_GR25(%r1)

	ldil	L%CLONE_UNTRACED, %r26

	ldo	CLONE_VM(%r26), %r26   /* Force CLONE_VM since only init_mm */

	or	%r26, %r24, %r26      /* will have kernel mappings.	 */

	ldi	1, %r25			/* stack_start, signals kernel thread */

	stw	%r0, -52(%r30)	     	/* user_tid */

#ifdef CONFIG_64BIT

	ldo	-16(%r30),%r29		/* Reference param save area */

#endif

	BL	do_fork, %r2

	copy	%r1, %r24		/* pt_regs */



	/* Parent Returns here */



	LDREG	-PT_SZ_ALGN-RP_OFFSET(%r30), %r2

	ldo	-PT_SZ_ALGN(%r30), %r30

	bv	%r0(%r2)

	nop

ENDPROC(__kernel_thread)



	/*

	 * Child Returns here

	 *

	 * copy_thread moved args from temp save area set up above

	 * into task save area.

	 * copy_thread moved args into task save area.

	 */



ENTRY(ret_from_kernel_thread)
@@ -773,7 +723,6 @@ ENTRY(ret_from_kernel_thread) 
	LDREG	TASK_PT_GR25(%r1), %r26

#ifdef CONFIG_64BIT

	LDREG	TASK_PT_GR27(%r1), %r27

	LDREG	TASK_PT_GR22(%r1), %r22

#endif

	LDREG	TASK_PT_GR26(%r1), %r1

	ble	0(%sr7, %r1)

arch/parisc/kernel/process.c

+16 −37
Original line number Diff line number Diff line
@@ -164,23 +164,6 @@ void machine_power_off(void) 
void (*pm_power_off)(void) = machine_power_off;

EXPORT_SYMBOL(pm_power_off);



/*

 * Create a kernel thread

 */



extern pid_t __kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);

pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)

{



	/*

	 * FIXME: Once we are sure we don't need any debug here,

	 *	  kernel_thread can become a #define.

	 */



	return __kernel_thread(fn, arg, flags);

}

EXPORT_SYMBOL(kernel_thread);



/*

 * Free current thread data structures etc..

 */
@@ -256,7 +239,7 @@ sys_vfork(struct pt_regs *regs) 


int

copy_thread(unsigned long clone_flags, unsigned long usp,

	    unsigned long unused,	/* in ia64 this is "user_stack_size" */

	    unsigned long arg,

	    struct task_struct *p, struct pt_regs *pregs)

{

	struct pt_regs * cregs = &(p->thread.regs);
@@ -271,21 +254,8 @@ copy_thread(unsigned long clone_flags, unsigned long usp, 
	extern void * const hpux_child_return;

#endif



	*cregs = *pregs;



	/* Set the return value for the child.  Note that this is not

           actually restored by the syscall exit path, but we put it

           here for consistency in case of signals. */

	cregs->gr[28] = 0; /* child */



	/*

	 * We need to differentiate between a user fork and a

	 * kernel fork. We can't use user_mode, because the

	 * the syscall path doesn't save iaoq. Right now

	 * We rely on the fact that kernel_thread passes

	 * in zero for usp.

	 */

	if (usp == 1) {

	if (unlikely((p->flags & PF_KTHREAD) && usp != 0)) {

		memset(cregs, 0, sizeof(struct pt_regs));

		/* kernel thread */

		cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN;

		/* Must exit via ret_from_kernel_thread in order
@@ -297,10 +267,12 @@ copy_thread(unsigned long clone_flags, unsigned long usp, 
		 * ret_from_kernel_thread.

		 */

#ifdef CONFIG_64BIT

		cregs->gr[27] = pregs->gr[27];

		cregs->gr[27] = ((unsigned long *)usp)[3];

		cregs->gr[26] = ((unsigned long *)usp)[2];

#else

		cregs->gr[26] = usp;

#endif

		cregs->gr[26] = pregs->gr[26];

		cregs->gr[25] = pregs->gr[25];

		cregs->gr[25] = arg;

	} else {

		/* user thread */

		/*
@@ -308,6 +280,13 @@ copy_thread(unsigned long clone_flags, unsigned long usp, 
		 * for setting gr[21].

		 */



		*cregs = *pregs;



		/* Set the return value for the child.  Note that this is not

		   actually restored by the syscall exit path, but we put it

		   here for consistency in case of signals. */

		cregs->gr[28] = 0; /* child */



		/* Use same stack depth as parent */

		cregs->ksp = (unsigned long)stack

			+ (pregs->gr[21] & (THREAD_SIZE - 1));