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Commit 9814cc11 authored by Michal Simek's avatar Michal Simek
Browse files

microblaze: Use delay slot in syscall macros 



Saving instruction with delay slot usage.

Signed-off-by: default avatarMichal Simek <monstr@monstr.eu>
parent da233552

arch/microblaze/kernel/entry.S

+10 −19
Original line number Diff line number Diff line
@@ -411,10 +411,8 @@ C_ENTRY(_user_exception): 


	/* The syscall number is invalid, return an error.  */

5:

	addi	r3, r0, -ENOSYS;

	rtsd	r15, 8;		/* looks like a normal subroutine return */

	or 	r0, r0, r0



	addi	r3, r0, -ENOSYS;



/* Entry point used to return from a syscall/trap */

/* We re-enable BIP bit before state restore */
@@ -491,9 +489,8 @@ C_ENTRY(sys_fork_wrapper): 
	addik	r7, r1, PTO			/* Arg 2: parent context */

	add	r8. r0, r0			/* Arg 3: (unused) */

	add	r9, r0, r0;			/* Arg 4: (unused) */

	add	r10, r0, r0;			/* Arg 5: (unused) */

	brid	do_fork		/* Do real work (tail-call) */

	nop;

	add	r10, r0, r0;			/* Arg 5: (unused) */



/* This the initial entry point for a new child thread, with an appropriate

   stack in place that makes it look the the child is in the middle of an
@@ -504,9 +501,8 @@ C_ENTRY(ret_from_fork): 
	bralid	r15, schedule_tail; /* ...which is schedule_tail's arg */

	add	r3, r5, r0;	/* switch_thread returns the prev task */

				/* ( in the delay slot ) */

	add	r3, r0, r0;	/* Child's fork call should return 0. */

	brid	ret_from_trap;	/* Do normal trap return */

	nop;

	add	r3, r0, r0;	/* Child's fork call should return 0. */



C_ENTRY(sys_vfork):

	brid	microblaze_vfork	/* Do real work (tail-call) */
@@ -518,21 +514,18 @@ C_ENTRY(sys_clone): 
1:	addik	r7, r1, PTO;			/* Arg 2: parent context */

	add	r8, r0, r0;			/* Arg 3: (unused) */

	add	r9, r0, r0;			/* Arg 4: (unused) */

	add	r10, r0, r0;			/* Arg 5: (unused) */

	brid	do_fork		/* Do real work (tail-call) */

	nop;

	add	r10, r0, r0;			/* Arg 5: (unused) */



C_ENTRY(sys_execve):

	addik	r8, r1, PTO;		/* add user context as 4th arg */

	brid	microblaze_execve;	/* Do real work (tail-call).*/

	nop;

	addik	r8, r1, PTO;		/* add user context as 4th arg */



C_ENTRY(sys_rt_sigreturn_wrapper):

	swi	r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */

	swi	r4, r1, PTO+PT_R4;

	addik	r5, r1, PTO;		/* add user context as 1st arg */

	brlid	r15, sys_rt_sigreturn	/* Do real work */

	nop;

	addik	r5, r1, PTO;		/* add user context as 1st arg */

	lwi	r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */

	lwi	r4, r1, PTO+PT_R4;

	bri ret_from_trap /* fall through will not work here due to align */
@@ -553,7 +546,6 @@ C_ENTRY(full_exception_trap): 
	 * I tested it but there is a fault */

	/* where the trap should return need -8 to adjust for rtsd r15, 8 */

	addik	r15, r0, ret_from_exc - 8

	addik	r5, r1, PTO		 /* parameter struct pt_regs * regs */

	mfs	r6, resr

	nop

	mfs	r7, rfsr;		/* save FSR */
@@ -561,7 +553,7 @@ C_ENTRY(full_exception_trap): 
	mts	rfsr, r0;	/* Clear sticky fsr */

	nop

	rted	r0, full_exception

	nop

	addik	r5, r1, PTO		 /* parameter struct pt_regs * regs */



/*

 * Unaligned data trap.
@@ -623,13 +615,12 @@ C_ENTRY(page_fault_data_trap): 
	tovirt(r1,r1)

	/* where the trap should return need -8 to adjust for rtsd r15, 8 */

	addik	r15, r0, ret_from_exc-8

	addik	r5, r1, PTO		/* parameter struct pt_regs * regs */

	mfs	r6, rear		/* parameter unsigned long address */

	nop

	mfs	r7, resr		/* parameter unsigned long error_code */

	nop

	rted	r0, do_page_fault

	nop

	addik	r5, r1, PTO		/* parameter struct pt_regs * regs */



C_ENTRY(page_fault_instr_trap):

	SAVE_STATE		/* Save registers.*/
@@ -638,11 +629,11 @@ C_ENTRY(page_fault_instr_trap): 
	tovirt(r1,r1)

	/* where the trap should return need -8 to adjust for rtsd r15, 8 */

	addik	r15, r0, ret_from_exc-8

	addik	r5, r1, PTO		/* parameter struct pt_regs * regs */

	mfs	r6, rear		/* parameter unsigned long address */

	nop

	rted	r0, do_page_fault

	ori	r7, r0, 0		/* parameter unsigned long error_code */

	rted	r0, do_page_fault

	addik	r5, r1, PTO		/* parameter struct pt_regs * regs */



/* Entry point used to return from an exception.  */

C_ENTRY(ret_from_exc):