microblaze: Use delay slot in syscall macros
Saving instruction with delay slot usage.
Signed-off-by: Michal Simek <monstr@monstr.eu>
diff --git a/arch/microblaze/kernel/entry.S b/arch/microblaze/kernel/entry.S
index 0747e1d..34100a5 100644
--- a/arch/microblaze/kernel/entry.S
+++ b/arch/microblaze/kernel/entry.S
@@ -411,10 +411,8 @@
/* The syscall number is invalid, return an error. */
5:
+ rtsd r15, 8; /* looks like a normal subroutine return */
addi r3, r0, -ENOSYS;
- rtsd r15,8; /* looks like a normal subroutine return */
- or r0, r0, r0
-
/* Entry point used to return from a syscall/trap */
/* We re-enable BIP bit before state restore */
@@ -491,9 +489,8 @@
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 @@
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 @@
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 @@
* 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 @@
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 @@
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 @@
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):