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From: David Howells <dhowells@redhat.com>
To: linux-am33-list@redhat.com
Cc: linux-kernel@vger.kernel.org,
	Akira Takeuchi <takeuchi.akr@jp.panasonic.com>,
	Kiyoshi Owada <owada.kiyoshi@jp.panasonic.com>
Subject: [PATCH 32/43] MN10300: Optimise do_csum()
Date: Tue, 26 Oct 2010 03:55:52 +0100	[thread overview]
Message-ID: <20101026025552.23512.17136.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <20101026025301.23512.24525.stgit@warthog.procyon.org.uk>

From: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>

Optimise do_csum() to gang up the loads so they're less likely to get
interruptions between.

Signed-off-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: Kiyoshi Owada <owada.kiyoshi@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>
---

 arch/mn10300/lib/do_csum.S |   49 ++++++++++++++++++++------------------------
 1 files changed, 22 insertions(+), 27 deletions(-)


diff --git a/arch/mn10300/lib/do_csum.S b/arch/mn10300/lib/do_csum.S
index e138994..1d27bba 100644
--- a/arch/mn10300/lib/do_csum.S
+++ b/arch/mn10300/lib/do_csum.S
@@ -10,26 +10,25 @@
  */
 #include <asm/cache.h>
 
-        .section .text
-        .balign	L1_CACHE_BYTES
+	.section .text
+	.balign	L1_CACHE_BYTES
 
 ###############################################################################
 #
-# unsigned int do_csum(const unsigned char *buff, size_t len)
+# unsigned int do_csum(const unsigned char *buff, int len)
 #
 ###############################################################################
 	.globl	do_csum
-        .type	do_csum,@function
+	.type	do_csum,@function
 do_csum:
 	movm	[d2,d3],(sp)
-	mov	d0,(12,sp)
-	mov	d1,(16,sp)
 	mov	d1,d2				# count
 	mov	d0,a0				# buff
+	mov	a0,a1
 	clr	d1				# accumulator
 
 	cmp	+0,d2
-	beq	do_csum_done			# return if zero-length buffer
+	ble	do_csum_done			# check for zero length or negative
 
 	# 4-byte align the buffer pointer
 	btst	+3,a0
@@ -41,17 +40,15 @@ do_csum:
 	inc	a0
 	asl	+8,d0
 	add	d0,d1
-	addc	+0,d1
 	add	-1,d2
-do_csum_addr_not_odd:
 
+do_csum_addr_not_odd:
 	cmp	+2,d2
 	bcs	do_csum_fewer_than_4
 	btst	+2,a0
 	beq	do_csum_now_4b_aligned
 	movhu	(a0+),d0
 	add	d0,d1
-	addc	+0,d1
 	add	-2,d2
 	cmp	+4,d2
 	bcs	do_csum_fewer_than_4
@@ -66,20 +63,20 @@ do_csum_now_4b_aligned:
 
 do_csum_loop:
 	mov	(a0+),d0
-	add	d0,d1
 	mov	(a0+),e0
-	addc	e0,d1
 	mov	(a0+),e1
-	addc	e1,d1
 	mov	(a0+),e3
+	add	d0,d1
+	addc	e0,d1
+	addc	e1,d1
 	addc	e3,d1
 	mov	(a0+),d0
-	addc	d0,d1
 	mov	(a0+),e0
-	addc	e0,d1
 	mov	(a0+),e1
-	addc	e1,d1
 	mov	(a0+),e3
+	addc	d0,d1
+	addc	e0,d1
+	addc	e1,d1
 	addc	e3,d1
 	addc	+0,d1
 
@@ -94,12 +91,12 @@ do_csum_remainder:
 	cmp	+16,d2
 	bcs	do_csum_fewer_than_16
 	mov	(a0+),d0
-	add	d0,d1
 	mov	(a0+),e0
-	addc	e0,d1
 	mov	(a0+),e1
-	addc	e1,d1
 	mov	(a0+),e3
+	add	d0,d1
+	addc	e0,d1
+	addc	e1,d1
 	addc	e3,d1
 	addc	+0,d1
 	add	-16,d2
@@ -131,9 +128,9 @@ do_csum_fewer_than_4:
 	xor_cmp	d0,d0,+2,d2
 	bcs	do_csum_fewer_than_2
 	movhu	(a0+),d0
-do_csum_fewer_than_2:
 	and	+1,d2
 	beq	do_csum_add_last_bit
+do_csum_fewer_than_2:
 	movbu	(a0),d3
 	add	d3,d0
 do_csum_add_last_bit:
@@ -142,21 +139,19 @@ do_csum_add_last_bit:
 
 do_csum_done:
 	# compress the checksum down to 16 bits
-	mov	+0xffff0000,d2
-	and	d1,d2
+	mov	+0xffff0000,d0
+	and	d1,d0
 	asl	+16,d1
-	add	d2,d1,d0
+	add	d1,d0
 	addc	+0xffff,d0
 	lsr	+16,d0
 
 	# flip the halves of the word result if the buffer was oddly aligned
-	mov	(12,sp),d1
-	and	+1,d1
+	and	+1,a1
 	beq	do_csum_not_oddly_aligned
 	swaph	d0,d0				# exchange bits 15:8 with 7:0
 
 do_csum_not_oddly_aligned:
 	ret	[d2,d3],8
 
-do_csum_end:
-	.size	do_csum, do_csum_end-do_csum
+	.size	do_csum, .-do_csum


  parent reply	other threads:[~2010-10-26  2:56 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-10-26  2:53 [PATCH 00/43] MN10300: Add SMP support and AM34 CPU core support David Howells
2010-10-26  2:53 ` [PATCH 01/43] Partially revert patch that encloses asm-offset.h numbers in brackets David Howells
2010-10-26  2:53 ` [PATCH 02/43] MN10300: BUG to BUG_ON changes David Howells
2010-10-26  2:53 ` [PATCH 03/43] bitops: Change the bitmap index from int to unsigned long [mn10300] David Howells
2010-10-26  2:53 ` [PATCH 04/43] mn10300: Use pci_claim_resource David Howells
2010-10-26  2:53 ` [PATCH 05/43] MN10300: Prevent cnt32_to_63() from being preempted in sched_clock() David Howells
2010-10-26  2:53 ` [PATCH 06/43] Typedef SMP call function pointer David Howells
2010-10-26  2:53 ` [PATCH 07/43] MN10300: Don't cast away the volatile in test_bit() David Howells
2010-10-26  2:53 ` [PATCH 08/43] MN10300: Add reads[bwl]() and writes[bwl]() David Howells
2010-10-26  2:53 ` [PATCH 09/43] MN10300: Provide the functions to fully disable maskable interrupts David Howells
2010-10-26  2:53 ` [PATCH 10/43] MN10300: Differentiate AM33_2 and AM33_3 in config David Howells
2010-10-26  2:54 ` [PATCH 11/43] MN10300: Move DMA engine control reg defs to MN103E010 processor directory David Howells
2010-10-26  2:54 ` [PATCH 12/43] MN10300: Don't hard code the cacheline size in register defs David Howells
2010-10-26  2:54 ` [PATCH 13/43] MN10300: Add CPU register bits for AM34 David Howells
2010-10-26  2:54 ` [PATCH 14/43] MN10300: Remove monitor/JTAG functions David Howells
2010-10-26  2:54 ` [PATCH 15/43] MN10300: Cache: Split cache bits out of arch Kconfig David Howells
2010-10-26  2:54 ` [PATCH 16/43] MN10300: Provide a MN10300_CACHE_ENABLED config option David Howells
2010-10-26  2:54 ` [PATCH 17/43] MN10300: Reorder asm/cacheflush.h to put primitives first David Howells
2010-10-26  2:54 ` [PATCH 18/43] MN10300: AM34: The current cacheflush routines operate by controlling tag regs David Howells
2010-10-26  2:54 ` [PATCH 19/43] MN10300: Cacheflush functions should take unsigned long addresses David Howells
2010-10-26  2:54 ` [PATCH 20/43] MN10300: SMP: Differentiate local cache flushing David Howells
2010-10-26  2:54 ` [PATCH 21/43] MN10300: AM34: Add cacheflushing by using the AM34 purge registers David Howells
2010-10-26  2:54 ` [PATCH 22/43] MN10300: Allow some cacheflushes to be avoided if cache snooping is available David Howells
2010-10-26  2:55 ` [PATCH 23/43] MN10300: Cache: Implement SMP global cache flushing David Howells
2010-10-26  2:55 ` [PATCH 24/43] MN10300: Make the boot wrapper able to use writeback caching David Howells
2010-10-26  2:55 ` [PATCH 25/43] MN10300: AM34 erratum requires MMUCTR read and write on exception entry David Howells
2010-10-26  2:55 ` [PATCH 26/43] MN10300: Rename __flush_tlb*() to local_flush_tlb*() David Howells
2010-10-26  2:55 ` [PATCH 27/43] MN10300: Make the use of PIDR to mark TLB entries controllable David Howells
2010-10-26  2:55 ` [PATCH 28/43] MN10300: Use the [ID]PTEL2 registers rather than [ID]PTEL for TLB control David Howells
2010-10-26  2:55 ` [PATCH 29/43] MN10300: SMP TLB flushing David Howells
2010-10-26  2:55 ` [PATCH 30/43] MN10300: Make the FPU operate in non-lazy mode under SMP David Howells
2010-10-26  2:55 ` [PATCH 31/43] MN10300: Implement atomic ops using atomic ops unit David Howells
2010-10-26  2:55 ` David Howells [this message]
2010-10-26  2:55 ` [PATCH 33/43] MN10300: Make various interrupt priority settings configurable David Howells
2010-10-26  2:56 ` [PATCH 34/43] MN10300: Delete idle_timestamp from irq_cpustat_t David Howells
2010-10-26  2:56 ` [PATCH 35/43] MN10300: And Panasonic AM34 subarch and implement SMP David Howells
2010-10-27 13:31   ` [Linux-am33-list] " Suzuki Takashi
2010-10-27 14:33   ` David Howells
2010-10-26  2:56 ` [PATCH 36/43] MN10300: ASB2364: Add support for SMSC911X and SMC911X David Howells
2010-10-26  2:56 ` [PATCH 37/43] MN10300: Map userspace atomic op regs as a vmalloc page David Howells
2010-10-26  2:56 ` [PATCH 38/43] MN10300: Specify an ELF HWCAP flag for MN10300 Atomic Operations Unit support David Howells
2010-10-26  2:56 ` [PATCH 39/43] MN10300: Generic time support David Howells
2010-10-26  2:56 ` [PATCH 40/43] MN10300: Update the ASB2303 defconfig David Howells
2010-10-26  2:56 ` [PATCH 41/43] MN10300: Create a defconfig for the ASB2364 board David Howells
2010-10-26  2:56 ` [PATCH 42/43] MN10300: Change "Matsushita" to "Panasonic" David Howells
2010-10-26  2:56 ` [PATCH 43/43] MN10300: Save frame pointer in thread_info struct rather than global var David Howells
2010-10-26  3:07 ` [PATCH 00/43] MN10300: Add SMP support and AM34 CPU core support David Howells

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