Switch DVB to generic crc32.

Switch DVB to generic crc32.

[David Woodhouse]

Not entirely sure why the DVB core code has its own crc32 table -- not only 
should it be using the one the kernel provides, but AFAICT nothing in the 
tree actually seem to _use_ its dvb_set_crc32() function anyway.

I'm assuming the latter is just a symptom of a partial merge and some 
driver not yet in the tree is going to use it... this patch fixes the 
former.

===== lib/Makefile 1.15 vs edited =====
--- 1.15/lib/Makefile	Wed Oct 30 01:19:29 2002
+++ edited/lib/Makefile	Fri Nov  8 10:56:03 2002
@@ -27,6 +27,7 @@
 obj-$(CONFIG_ZLIB_INFLATE) += zlib_inflate/
 obj-$(CONFIG_ZLIB_DEFLATE) += zlib_deflate/
 
+include $(TOPDIR)/drivers/media/dvb/dvb-core/Makefile.lib
 include $(TOPDIR)/drivers/net/Makefile.lib
 include $(TOPDIR)/drivers/usb/class/Makefile.lib
 include $(TOPDIR)/fs/Makefile.lib
===== drivers/media/dvb/dvb-core/dvb_demux.c 1.1 vs edited =====
--- 1.1/drivers/media/dvb/dvb-core/dvb_demux.c	Tue Oct 22 15:48:37 2002
+++ edited/drivers/media/dvb/dvb-core/dvb_demux.c	Fri Nov  8 10:57:24 2002
@@ -24,6 +24,7 @@
 #include <linux/vmalloc.h>
 #include <linux/module.h>
 #include <linux/poll.h>
+#include <linux/crc32.h>
 #include <linux/version.h>
 #include <asm/uaccess.h>
 
@@ -108,68 +109,11 @@
         return 184;
 }
 
-
-static u32 
-dvb_crc_table[256] = {
-	0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
-	0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
-	0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7,
-	0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
-	0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3,
-	0x709f7b7a, 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
-	0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58, 0xbaea46ef,
-	0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
-	0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb,
-	0xceb42022, 0xca753d95, 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
-	0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
-	0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
-	0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x018aeb13, 0x054bf6a4,
-	0x0808d07d, 0x0cc9cdca, 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
-	0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08,
-	0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
-	0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc,
-	0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
-	0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 0xe0b41de7, 0xe4750050,
-	0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
-	0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
-	0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
-	0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 0x4f040d56, 0x4bc510e1,
-	0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
-	0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5,
-	0x3f9b762c, 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
-	0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e, 0xf5ee4bb9,
-	0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
-	0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd,
-	0xcda1f604, 0xc960ebb3, 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
-	0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
-	0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
-	0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2,
-	0x470cdd2b, 0x43cdc09c, 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
-	0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e,
-	0x18197087, 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
-	0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a,
-	0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
-	0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 0xe3a1cbc1, 0xe760d676,
-	0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
-	0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
-	0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
-	0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4};
-
-u32 dvb_crc32(u8 *data, int len)
-{
-	int i;
-	u32 crc = 0xffffffff;
-
-	for (i=0; i<len; i++)
-                crc = (crc << 8) ^ dvb_crc_table[((crc >> 24) ^ *data++) & 0xff];
-	return crc;
-}
-
 void dvb_set_crc32(u8 *data, int length)
 {
         u32 crc;
 
-        crc=dvb_crc32(data,length);
+        crc=crc32_le(~0, data, length);
         data[length]   = (crc>>24)&0xff;
         data[length+1] = (crc>>16)&0xff;
         data[length+2] = (crc>>8)&0xff;
--- /dev/null	Sat Aug 31 00:31:37 2002
+++ edited/drivers/media/dvb/dvb-core/Makefile.lib	Fri Nov  8 10:55:14 2002
@@ -0,0 +1 @@
+obj-$(CONFIG_DVB_CORE)		+= crc32.o


--
dwmw2

Re: Switch DVB to generic crc32.

[Holger Waechtler]

David Woodhouse wrote:
> Not entirely sure why the DVB core code has its own crc32 table -- not only 
> should it be using the one the kernel provides, but AFAICT nothing in the 
> tree actually seem to _use_ its dvb_set_crc32() function anyway.

the crc32 table was defined because the same driver works for 2.4 
kernels, there we need our own crc32 implementation. I'll check if we 
can use the generic code in the kernel and then move the dvb_crc32 code 
into the 2.4 compatibility file compat.c

That the crc32 check is currently not called by the software 
demultiplexer is a known bug, it's already fixed in local CVS and will 
get into the kernel with the next patchset. I'm currently preparing this 
patchset but want to test it a little more.

Alan: do you have doubts or is there a reason not to apply the last 
patchset I sent you on Tue, 29 Oct 2002? (well - it was kind of huge, 
but all the namespace fixes and cleanups should justify the patch's 
size, not?)

Holger

Re: Switch DVB to generic crc32.

[David Woodhouse]

holger@convergence.de said:
>  the crc32 table was defined because the same driver works for 2.4
> kernels, there we need our own crc32 implementation.

JFFS2 in 2.4 has the same problem. The fix is to backport the 2.5 crc32 
code so that 2.4 isn't gratuitously different. That patch has been sent to 
Alan already, I believe it's going to be sent to Marcelo for 2.4.21-pre1.

--
dwmw2

Re: Switch DVB to generic crc32.

[Holger Waechtler]

Hi David,

I'm looking on the generic crc32 code right now, but need some time to 
completely understand the code. Have you checked that this code 
implements the same generator polynomial as defined in the DVB standard?

Holger

Re: Switch DVB to generic crc32.

[David Woodhouse]

[-- Attachment #1: Type: text/plain, Size: 273 bytes --]


holger@convergence.de said:
>  I'm looking on the generic crc32 code right now, but need some time
> to  completely understand the code. Have you checked that this code
> implements the same generator polynomial as defined in the DVB
> standard? 

sort of...



--
dwmw2


[-- Attachment #2: testfish.c --]
[-- Type: text/plain , Size: 3846 bytes --]

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/crc32.h>

static u32 
dvb_crc_table[256] = {
	0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
	0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
	0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7,
	0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
	0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3,
	0x709f7b7a, 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
	0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58, 0xbaea46ef,
	0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
	0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb,
	0xceb42022, 0xca753d95, 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
	0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
	0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
	0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x018aeb13, 0x054bf6a4,
	0x0808d07d, 0x0cc9cdca, 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
	0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08,
	0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
	0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc,
	0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
	0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 0xe0b41de7, 0xe4750050,
	0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
	0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
	0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
	0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 0x4f040d56, 0x4bc510e1,
	0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
	0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5,
	0x3f9b762c, 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
	0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e, 0xf5ee4bb9,
	0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
	0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd,
	0xcda1f604, 0xc960ebb3, 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
	0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
	0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
	0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2,
	0x470cdd2b, 0x43cdc09c, 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
	0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e,
	0x18197087, 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
	0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a,
	0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
	0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 0xe3a1cbc1, 0xe760d676,
	0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
	0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
	0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
	0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4};

u32 dvb_crc32(u8 *data, int len)
{
	int i;
	u32 crc = 0xffffffff;

	for (i=0; i<len; i++)
                crc = (crc << 8) ^ dvb_crc_table[((crc >> 24) ^ *data++) & 0xff];
	return crc;
}

int fish(void)
{

	printk("dvb_crc32 is %08x\n", dvb_crc32("fishyfishyfishies", 13));
	printk("crc32_le(0) %08x\n", crc32_le(0,     "fishyfishyfishies", 13));
	printk("crc32_le(-1) %08x\n", crc32_le(-1,     "fishyfishyfishies", 13));
	printk("crc32_be(0) %08x\n", crc32_be(0,     "fishyfishyfishies", 13));
	printk("crc32_le(-1) %08x\n", crc32_be(-1,     "fishyfishyfishies", 13));

}
module_init(fish);

Re: Switch DVB to generic crc32.

[Alan Cox]

On Fri, 2002-11-08 at 13:57, Holger Waechtler wrote:
> Alan: do you have doubts or is there a reason not to apply the last 
> patchset I sent you on Tue, 29 Oct 2002? (well - it was kind of huge, 
> but all the namespace fixes and cleanups should justify the patch's 
> size, not?)

I've just been rather busy thats all