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Message-ID: <20131022183625.GA4382@breakpoint.cc>
Date: Tue, 22 Oct 2013 20:36:25 +0200
From: Sebastian Andrzej Siewior <sebastian@...akpoint.cc>
To: David Miller <davem@...emloft.net>
Cc: andi@...stfloor.org, akpm@...ux-foundation.org,
linux-kernel@...r.kernel.org, ak@...ux.intel.com,
netdev@...r.kernel.org
Subject: [PATCH] net: wan: sbni: remove assembly crc32 code
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@...akpoint.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
--
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