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Commit 42472a74 authored by Al Viro's avatar Al Viro
Browse files

Merge branch 'arch-hexagon' into no-rebases

parents 94b237b6 27aedbd5

arch/hexagon/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -31,6 +31,8 @@ config HEXAGON 
	select GENERIC_CLOCKEVENTS

	select GENERIC_CLOCKEVENTS_BROADCAST

	select MODULES_USE_ELF_RELA

	select GENERIC_KERNEL_THREAD

	select GENERIC_KERNEL_EXECVE

	---help---

	  Qualcomm Hexagon is a processor architecture designed for high

	  performance and low power across a wide variety of applications.

arch/hexagon/include/asm/processor.h

+0 −1
Original line number Diff line number Diff line
@@ -34,7 +34,6 @@ 
struct task_struct;



/*  this is defined in arch/process.c  */

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

extern unsigned long thread_saved_pc(struct task_struct *tsk);



extern void start_thread(struct pt_regs *, unsigned long, unsigned long);

arch/hexagon/include/asm/ptrace.h

+4 −0
Original line number Diff line number Diff line
@@ -32,4 +32,8 @@ 
extern int regs_query_register_offset(const char *name);

extern const char *regs_query_register_name(unsigned int offset);



#define current_pt_regs() \

	((struct pt_regs *) \

	 ((unsigned long)current_thread_info() + THREAD_SIZE) - 1)



#endif

arch/hexagon/include/asm/unistd.h

+1 −0
Original line number Diff line number Diff line
@@ -27,5 +27,6 @@ 
 */



#define sys_mmap2 sys_mmap_pgoff

#define __ARCH_WANT_SYS_EXECVE



#include <asm-generic/unistd.h>

arch/hexagon/kernel/process.c

+32 −70
Original line number Diff line number Diff line
@@ -25,33 +25,6 @@ 
#include <linux/uaccess.h>

#include <linux/slab.h>



/*

 * Kernel thread creation.  The desired kernel function is "wrapped"

 * in the kernel_thread_helper function, which does cleanup

 * afterwards.

 */

static void __noreturn kernel_thread_helper(void *arg, int (*fn)(void *))

{

	do_exit(fn(arg));

}



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

{

	struct pt_regs regs;



	memset(&regs, 0, sizeof(regs));

	/*

	 * Yes, we're exploting illicit knowledge of the ABI here.

	 */

	regs.r00 = (unsigned long) arg;

	regs.r01 = (unsigned long) fn;

	pt_set_elr(&regs, (unsigned long)kernel_thread_helper);

	pt_set_kmode(&regs);



	return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);

}

EXPORT_SYMBOL(kernel_thread);



/*

 * Program thread launch.  Often defined as a macro in processor.h,

 * but we're shooting for a small footprint and it's not an inner-loop
@@ -114,7 +87,7 @@ unsigned long thread_saved_pc(struct task_struct *tsk) 
 * Copy architecture-specific thread state

 */

int copy_thread(unsigned long clone_flags, unsigned long usp,

		unsigned long unused, struct task_struct *p,

		unsigned long arg, struct task_struct *p,

		struct pt_regs *regs)

{

	struct thread_info *ti = task_thread_info(p);
@@ -125,19 +98,28 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, 
	childregs = (struct pt_regs *) (((unsigned long) ti + THREAD_SIZE) -

					sizeof(*childregs));



	memcpy(childregs, regs, sizeof(*childregs));

	ti->regs = childregs;



	/*

	 * Establish kernel stack pointer and initial PC for new thread

	 * Note that unlike the usual situation, we do not copy the

	 * parent's callee-saved here; those are in pt_regs and whatever

	 * we leave here will be overridden on return to userland.

	 */

	ss = (struct hexagon_switch_stack *) ((unsigned long) childregs -

						    sizeof(*ss));

	ss->lr = (unsigned long)ret_from_fork;

	p->thread.switch_sp = ss;

	if (unlikely(p->flags & PF_KTHREAD)) {

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

		/* r24 <- fn, r25 <- arg */

		ss->r2524 = usp | ((u64)arg << 32);

		pt_set_kmode(childregs);

		return 0;

	}

	memcpy(childregs, regs, sizeof(*childregs));

	ss->r2524 = 0;



	/* If User mode thread, set pt_reg stack pointer as per parameter */

	if (user_mode(childregs)) {

	pt_set_rte_sp(childregs, usp);



	/* Child sees zero return value */
@@ -160,26 +142,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, 
	 * this point in the fork process

	 * Might also want to set things like ti->addr_limit

	 */

	} else {

		/*

		 * If kernel thread, resume stack is kernel stack base.

		 * Note that this is pointer arithmetic on pt_regs *

		 */

		pt_set_rte_sp(childregs, (unsigned long)(childregs + 1));

		/*

		 * We need the current thread_info fast path pointer

		 * set up in pt_regs.  The register to be used is

		 * parametric for assembler code, but the mechanism

		 * doesn't drop neatly into C.  Needs to be fixed.

		 */

		childregs->THREADINFO_REG = (unsigned long) ti;

	}



	/*

	 * thread_info pointer is pulled out of task_struct "stack"

	 * field on switch_to.

	 */

	p->stack = (void *)ti;



	return 0;

}