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From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Nicholas Piggin <npiggin@gmail.com>
Subject: [PATCH v2 34/44] powerpc/64s/exception: program check handler do not branch into a macro
Date: Fri,  2 Aug 2019 20:56:59 +1000	[thread overview]
Message-ID: <20190802105709.27696-35-npiggin@gmail.com> (raw)
In-Reply-To: <20190802105709.27696-1-npiggin@gmail.com>

It is clever, but the small code saving is not worth the spaghetti of
jumping to a label in an expanded macro, particularly when the label
is just a number rather than a descriptive name.

So expand the INT_COMMON macro twice, once for the stack and no stack
cases, and branch to those. The slight code size increase is worth
the improved clarity of branches for this non-performance critical
code.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 5532923a9aac..3ebb39a4b9fa 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -533,11 +533,10 @@ END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,948)
 	andi.	r10,r12,MSR_PR		/* See if coming from user	*/
 	mr	r10,r1			/* Save r1			*/
 	subi	r1,r1,INT_FRAME_SIZE	/* alloc frame on kernel stack	*/
-	beq-	1f
+	beq-	100f
 	ld	r1,PACAKSAVE(r13)	/* kernel stack to use		*/
-1:	tdgei	r1,-INT_FRAME_SIZE	/* trap if r1 is in userspace	*/
-	EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0
-3:
+100:	tdgei	r1,-INT_FRAME_SIZE	/* trap if r1 is in userspace	*/
+	EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,0
 	.endif
 
 	std	r9,_CCR(r1)		/* save CR in stackframe	*/
@@ -551,10 +550,10 @@ END_FTR_SECTION_NESTED(CPU_FTR_HAS_PPR,CPU_FTR_HAS_PPR,948)
 	.if \kaup
 	kuap_save_amr_and_lock r9, r10, cr1, cr0
 	.endif
-	beq	4f			/* if from kernel mode		*/
+	beq	101f			/* if from kernel mode		*/
 	ACCOUNT_CPU_USER_ENTRY(r13, r9, r10)
 	SAVE_PPR(\area, r9)
-4:
+101:
 	.else
 	.if \kaup
 	kuap_save_amr_and_lock r9, r10, cr1
@@ -1325,9 +1324,11 @@ EXC_COMMON_BEGIN(program_check_common)
 	mr	r10,r1			/* Save r1			*/
 	ld	r1,PACAEMERGSP(r13)	/* Use emergency stack		*/
 	subi	r1,r1,INT_FRAME_SIZE	/* alloc stack frame		*/
-	b 3f				/* Jump into the macro !!	*/
+	INT_COMMON 0x700, PACA_EXGEN, 0, 1, 1, 0, 0
+	b 3f
 2:
 	INT_COMMON 0x700, PACA_EXGEN, 1, 1, 1, 0, 0
+3:
 	bl	save_nvgprs
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	program_check_exception
-- 
2.22.0


  parent reply	other threads:[~2019-08-02 12:21 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-02 10:56 [PATCH v2 00/44] powerpc/64s/exception: cleanup and macrofiy, Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 01/44] powerpc/64s/exception: machine check fwnmi remove HV case Nicholas Piggin
2019-09-02  3:29   ` Michael Ellerman
2019-08-02 10:56 ` [PATCH v2 02/44] powerpc/64s/exception: machine check remove bitrotted comment Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 03/44] powerpc/64s/exception: machine check fix KVM guest test Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 04/44] powerpc/64s/exception: machine check adjust RFI target Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 05/44] powerpc/64s/exception: machine check pseries should always run the early handler Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 06/44] powerpc/64s/exception: machine check remove machine_check_pSeries_0 branch Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 07/44] powerpc/64s/exception: machine check use correct cfar for late handler Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 08/44] powerpc/64s/powernv: machine check dump SLB contents Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 09/44] powerpc/64s/pseries: machine check convert to use common event code Nicholas Piggin
2019-08-08  5:01   ` kbuild test robot
2019-08-16 22:25     ` Michael Ellerman
2019-08-19 13:09       ` Nicholas Piggin
2019-08-08  5:50   ` kbuild test robot
2019-08-02 10:56 ` [PATCH v2 10/44] powerpc/64s/exception: machine check pseries should skip the late handler for kernel MCEs Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 11/44] powerpc/64s/exception: machine check restructure to reuse common macros Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 12/44] powerpc/64s/exception: machine check move tramp code Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 13/44] powerpc/64s/exception: simplify machine check early path Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 14/44] powerpc/64s/exception: machine check move unrecoverable handling out of line Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 15/44] powerpc/64s/exception: untangle early machine check handler branch Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 16/44] powerpc/64s/exception: machine check improve labels and comments Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 17/44] powerpc/64s/exception: Fix DAR load for handle_page_fault error case Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 18/44] powerpc/64s/exception: move head-64.h exception code to exception-64s.S Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 19/44] powerpc/64s/exception: Add EXC_HV_OR_STD, which selects HSRR if HVMODE Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 20/44] powerpc/64s/exception: Fix performance monitor virt handler Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 21/44] powerpc/64s/exception: remove 0xb00 handler Nicholas Piggin
2019-08-21 12:18   ` Michael Ellerman
2019-08-02 10:56 ` [PATCH v2 22/44] powerpc/64s/exception: Replace PROLOG macros and EXC helpers with a gas macro Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 23/44] powerpc/64s/exception: remove EXCEPTION_PROLOG_0/1, rename _2 Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 24/44] powerpc/64s/exception: Add the virt variant of the denorm interrupt handler Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 25/44] powerpc/64s/exception: INT_HANDLER support HDAR/HDSISR and use it in HDSI Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 26/44] powerpc/64s/exception: Add INT_KVM_HANDLER gas macro Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 27/44] powerpc/64s/exception: KVM_HANDLER reorder arguments to match other macros Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 28/44] powerpc/64s/exception: Merge EXCEPTION_PROLOG_COMMON_2/3 Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 29/44] powerpc/64s/exception: Add INT_COMMON gas macro to generate common exception code Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 30/44] powerpc/64s/exception: Expand EXCEPTION_COMMON macro into caller Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 31/44] powerpc/64s/exception: Expand EXCEPTION_PROLOG_COMMON_1 and 2 " Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 32/44] powerpc/64s/exception: INT_COMMON add DAR, DSISR, reconcile options Nicholas Piggin
2019-08-02 10:56 ` [PATCH v2 33/44] powerpc/64s/exception: move interrupt entry code above the common handler Nicholas Piggin
2019-08-02 10:56 ` Nicholas Piggin [this message]
2019-08-02 10:57 ` [PATCH v2 35/44] powerpc/64s/exception: Remove pointless KVM handler name bifurcation Nicholas Piggin
2019-08-02 10:57 ` [PATCH v2 36/44] powerpc/64s/exception: reduce page fault unnecessary loads Nicholas Piggin
2019-08-02 10:57 ` [PATCH v2 37/44] powerpc/64s/exception: Introduce INT_DEFINE parameter block for code generation Nicholas Piggin
2019-08-02 10:57 ` [PATCH v2 38/44] powerpc/64s/exception: Add GEN_COMMON macro that uses INT_DEFINE parameters Nicholas Piggin
2019-08-02 10:57 ` [PATCH v2 39/44] powerpc/64s/exception: Add GEN_KVM " Nicholas Piggin
2019-08-02 10:57 ` [PATCH v2 40/44] powerpc/64s/exception: Expand EXC_COMMON and EXC_COMMON_ASYNC macros Nicholas Piggin
2019-08-02 10:57 ` [PATCH v2 41/44] powerpc/64s/exception: Move all interrupt handlers to new style code gen macros Nicholas Piggin
2019-08-02 10:57 ` [PATCH v2 42/44] powerpc/64s/exception: Remove old INT_ENTRY macro Nicholas Piggin
2019-08-02 10:57 ` [PATCH v2 43/44] powerpc/64s/exception: Remove old INT_COMMON macro Nicholas Piggin
2019-08-02 10:57 ` [PATCH v2 44/44] powerpc/64s/exception: Remove old INT_KVM_HANDLER Nicholas Piggin

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