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From: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
To: David Miller <davem@davemloft.net>
Cc: andi@firstfloor.org, akpm@linux-foundation.org,
	linux-kernel@vger.kernel.org, ak@linux.intel.com,
	netdev@vger.kernel.org
Subject: [PATCH] net: wan: sbni: remove assembly crc32 code
Date: Tue, 22 Oct 2013 20:36:25 +0200	[thread overview]
Message-ID: <20131022183625.GA4382@breakpoint.cc> (raw)
In-Reply-To: <20131022.135928.2040131908206663695.davem@davemloft.net>


There is also a C function doing the same thing. Unless the asm code is
110% faster we could stick to the C function.

Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
---

On Tue, Oct 22, 2013 at 01:59:28PM -0400, David Miller wrote:
> 
> Is it really impossible to use the generic crc32 support instead of this
> unsightly custom inline assembler?

Since you asked for this here step 1.

 drivers/net/wan/sbni.c | 89 --------------------------------------------------
 1 file changed, 89 deletions(-)

diff --git a/drivers/net/wan/sbni.c b/drivers/net/wan/sbni.c
index 5bbcb5e..388ddf6 100644
--- a/drivers/net/wan/sbni.c
+++ b/drivers/net/wan/sbni.c
@@ -148,10 +148,6 @@ static int  enslave( struct net_device *, struct net_device * );
 static int  emancipate( struct net_device * );
 #endif
 
-#ifdef __i386__
-#define ASM_CRC 1
-#endif
-
 static const char  version[] =
 	"Granch SBNI12 driver ver 5.0.1  Jun 22 2001  Denis I.Timofeev.\n";
 
@@ -1551,88 +1547,6 @@ __setup( "sbni=", sbni_setup );
 
 /* -------------------------------------------------------------------------- */
 
-#ifdef ASM_CRC
-
-static u32
-calc_crc32( u32  crc,  u8  *p,  u32  len )
-{
-	register u32  _crc;
-	_crc = crc;
-	
-	__asm__ __volatile__ (
-		"xorl	%%ebx, %%ebx\n"
-		"movl	%2, %%esi\n" 
-		"movl	%3, %%ecx\n" 
-		"movl	$crc32tab, %%edi\n"
-		"shrl	$2, %%ecx\n"
-		"jz	1f\n"
-
-		".align 4\n"
-	"0:\n"
-		"movb	%%al, %%bl\n"
-		"movl	(%%esi), %%edx\n"
-		"shrl	$8, %%eax\n"
-		"xorb	%%dl, %%bl\n"
-		"shrl	$8, %%edx\n"
-		"xorl	(%%edi,%%ebx,4), %%eax\n"
-
-		"movb	%%al, %%bl\n"
-		"shrl	$8, %%eax\n"
-		"xorb	%%dl, %%bl\n"
-		"shrl	$8, %%edx\n"
-		"xorl	(%%edi,%%ebx,4), %%eax\n"
-
-		"movb	%%al, %%bl\n"
-		"shrl	$8, %%eax\n"
-		"xorb	%%dl, %%bl\n"
-		"movb	%%dh, %%dl\n" 
-		"xorl	(%%edi,%%ebx,4), %%eax\n"
-
-		"movb	%%al, %%bl\n"
-		"shrl	$8, %%eax\n"
-		"xorb	%%dl, %%bl\n"
-		"addl	$4, %%esi\n"
-		"xorl	(%%edi,%%ebx,4), %%eax\n"
-
-		"decl	%%ecx\n"
-		"jnz	0b\n"
-
-	"1:\n"
-		"movl	%3, %%ecx\n"
-		"andl	$3, %%ecx\n"
-		"jz	2f\n"
-
-		"movb	%%al, %%bl\n"
-		"shrl	$8, %%eax\n"
-		"xorb	(%%esi), %%bl\n"
-		"xorl	(%%edi,%%ebx,4), %%eax\n"
-
-		"decl	%%ecx\n"
-		"jz	2f\n"
-
-		"movb	%%al, %%bl\n"
-		"shrl	$8, %%eax\n"
-		"xorb	1(%%esi), %%bl\n"
-		"xorl	(%%edi,%%ebx,4), %%eax\n"
-
-		"decl	%%ecx\n"
-		"jz	2f\n"
-
-		"movb	%%al, %%bl\n"
-		"shrl	$8, %%eax\n"
-		"xorb	2(%%esi), %%bl\n"
-		"xorl	(%%edi,%%ebx,4), %%eax\n"
-	"2:\n"
-		: "=a" (_crc)
-		: "0" (_crc), "g" (p), "g" (len)
-		: "bx", "cx", "dx", "si", "di"
-	);
-
-	return  _crc;
-}
-
-#else	/* ASM_CRC */
-
 static u32
 calc_crc32( u32  crc,  u8  *p,  u32  len )
 {
@@ -1642,9 +1556,6 @@ calc_crc32( u32  crc,  u8  *p,  u32  len )
 	return  crc;
 }
 
-#endif	/* ASM_CRC */
-
-
 static u32  crc32tab[] __attribute__ ((aligned(8))) = {
 	0xD202EF8D,  0xA505DF1B,  0x3C0C8EA1,  0x4B0BBE37,
 	0xD56F2B94,  0xA2681B02,  0x3B614AB8,  0x4C667A2E,
-- 
1.8.4.rc3


  reply	other threads:[~2013-10-22 18:36 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-10-22 16:12 Various asmlinkage fixes for LTO Andi Kleen
2013-10-22 16:12 ` [PATCH 01/11] asmlinkage, kvm: Make kvm_rebooting visible Andi Kleen
2013-10-30  9:27   ` Gleb Natapov
2013-10-22 16:12 ` [PATCH 02/11] asmlinkage: Make __iowrite32_copy visible Andi Kleen
2013-10-26 10:02   ` Ingo Molnar
2013-10-22 16:12 ` [PATCH 03/11] asmlinkage: Make jiffies visible Andi Kleen
2013-10-22 16:12 ` [PATCH 04/11] asmlinkage, pnp: Make variables used from assembler code visible Andi Kleen
2013-10-22 16:12 ` [PATCH 05/11] asmlinkage: Make lockdep_sys_exit asmlinkage Andi Kleen
2013-10-22 16:12 ` [PATCH 06/11] asmlinkage: Make trace_hardirq visible Andi Kleen
2013-10-22 20:18   ` Peter Zijlstra
2013-10-23  2:15     ` Andi Kleen
2013-10-22 16:12 ` [PATCH 07/11] asmlinkage, module: Make ksymtab and kcrctab symbols and __this_module __visible Andi Kleen
2013-10-23  1:09   ` Rusty Russell
2013-10-22 16:12 ` [PATCH 08/11] asmlinkage, mutex: Mark __visible Andi Kleen
2013-10-22 16:12 ` [PATCH 09/11] asmlinkage: Make main_extable_sort_needed visible Andi Kleen
2013-10-22 16:12 ` [PATCH 10/11] asmlinkage: Mark rwsem functions that can be called from assembler asmlinkage Andi Kleen
2013-10-22 16:12 ` [PATCH 11/11] asmlinkage, wan/sbni: Make inline assembler symbols visible and assembler global Andi Kleen
2013-10-22 17:59   ` David Miller
2013-10-22 18:36     ` Sebastian Andrzej Siewior [this message]
2013-10-22 18:38       ` [PATCH] net: wan: sbni: remove assembly crc32 code David Miller
2013-10-23  2:11       ` Andi Kleen
2013-10-25 23:27       ` David Miller
2013-10-23  2:09     ` [PATCH 11/11] asmlinkage, wan/sbni: Make inline assembler symbols visible and assembler global Andi Kleen
2013-10-23  2:15       ` Florian Fainelli
2013-10-23  2:22         ` Andi Kleen
2013-10-23  6:28         ` Francois Romieu

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