From 9814cc11e559d982874f6ebac2bc795e33cb0244 Mon Sep 17 00:00:00 2001 From: Michal Simek Date: Tue, 22 Jun 2010 18:09:29 +0200 Subject: [PATCH] microblaze: Use delay slot in syscall macros Saving instruction with delay slot usage. Signed-off-by: Michal Simek --- arch/microblaze/kernel/entry.S | 29 ++++++++++------------------- 1 file changed, 10 insertions(+), 19 deletions(-) diff --git a/arch/microblaze/kernel/entry.S b/arch/microblaze/kernel/entry.S index 0747e1d61d55..34100a526194 100644 --- a/arch/microblaze/kernel/entry.S +++ b/arch/microblaze/kernel/entry.S @@ -411,10 +411,8 @@ C_ENTRY(_user_exception): /* 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 @@ 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): -- 2.39.2