Re: [PATCH v4 19/24] openrisc: entry: Whitespace and comment cleanups

From: Jonas Bonn
Date: Fri Feb 24 2017 - 04:45:26 EST


On 02/24/2017 05:32 AM, Stafford Horne wrote:
Cleanups to whitespace and add some comments. Reading through the delay
slot logic I noticed some things:
- Delay slot instructions were not indented
- Some comments are not lined up
- Use tabs and spaces consistent with other code

No functional change

No, don't do this. Whitespace cleanups like this make life difficult for people rebasing on your tree, as well as blunting useful tools like git blame.

I'm not against the indentation of the delay slot instructions; that seems sane and should be pretty transparent in a merge conflict.

The whitespace cleanup and tab-space toggling needs to go, though. These sorts of things are better fixed up when the code lines they apply to are changed for other, functional reasons.

I suggest you pull out the delay slot fixups into a separate patch and then just sit on the rest until you've discovered the pain of whitespace cleanup-inflicted merge conflicts and decide to just ditch them altogether.

/Jonas


Signed-off-by: Stafford Horne <shorne@xxxxxxxxx>
---
arch/openrisc/kernel/entry.S | 38 ++++++++++++++++++--------------------
1 file changed, 18 insertions(+), 20 deletions(-)

diff --git a/arch/openrisc/kernel/entry.S b/arch/openrisc/kernel/entry.S
index ba1a361..daae2a4 100644
--- a/arch/openrisc/kernel/entry.S
+++ b/arch/openrisc/kernel/entry.S
@@ -228,7 +228,7 @@ EXCEPTION_ENTRY(_data_page_fault_handler)
* DTLB miss handler in the CONFIG_GUARD_PROTECTED_CORE part
*/
#ifdef CONFIG_OPENRISC_NO_SPR_SR_DSX
- l.lwz r6,PT_PC(r3) // address of an offending insn
+ l.lwz r6,PT_PC(r3) // address of an offending insn
l.lwz r6,0(r6) // instruction that caused pf
l.srli r6,r6,26 // check opcode for jump insn
@@ -244,49 +244,47 @@ EXCEPTION_ENTRY(_data_page_fault_handler)
l.bf 8f
l.sfeqi r6,0x12 // l.jalr
l.bf 8f
-
- l.nop
+ l.nop
l.j 9f
- l.nop
-8:
+ l.nop
- l.lwz r6,PT_PC(r3) // address of an offending insn
+8: // offending insn is in delay slot
+ l.lwz r6,PT_PC(r3) // address of an offending insn
l.addi r6,r6,4
l.lwz r6,0(r6) // instruction that caused pf
l.srli r6,r6,26 // get opcode
-9:
+9: // offending instruction opcode loaded in r6
#else
- l.mfspr r6,r0,SPR_SR // SR
-// l.lwz r6,PT_SR(r3) // ESR
- l.andi r6,r6,SPR_SR_DSX // check for delay slot exception
- l.sfeqi r6,0x1 // exception happened in delay slot
- l.bnf 7f
- l.lwz r6,PT_PC(r3) // address of an offending insn
+ l.mfspr r6,r0,SPR_SR // SR
+ l.andi r6,r6,SPR_SR_DSX // check for delay slot exception
+ l.sfeqi r6,0x1 // exception happened in delay slot
+ l.bnf 7f
+ l.lwz r6,PT_PC(r3) // address of an offending insn
- l.addi r6,r6,4 // offending insn is in delay slot
+ l.addi r6,r6,4 // offending insn is in delay slot
7:
l.lwz r6,0(r6) // instruction that caused pf
l.srli r6,r6,26 // check opcode for write access
#endif
- l.sfgeui r6,0x33 // check opcode for write access
+ l.sfgeui r6,0x33 // check opcode for write access
l.bnf 1f
l.sfleui r6,0x37
l.bnf 1f
l.ori r6,r0,0x1 // write access
l.j 2f
- l.nop
+ l.nop
1: l.ori r6,r0,0x0 // !write access
2:
/* call fault.c handler in or32/mm/fault.c */
l.jal do_page_fault
- l.nop
+ l.nop
l.j _ret_from_exception
- l.nop
+ l.nop
/* ---[ 0x400: Insn Page Fault exception ]------------------------------- */
EXCEPTION_ENTRY(_itlb_miss_page_fault_handler)
@@ -306,9 +304,9 @@ EXCEPTION_ENTRY(_insn_page_fault_handler)
/* call fault.c handler in or32/mm/fault.c */
l.jal do_page_fault
- l.nop
+ l.nop
l.j _ret_from_exception
- l.nop
+ l.nop
/* ---[ 0x500: Timer exception ]----------------------------------------- */