RE: crc32 cleanups

Matt_Domsch
2001-10-16T19:05:38Z

Changes since last time:
* A lot more drivers were updated. These had in-lined the CRC32 code
(either BE or LE). I think I got them all except natsemi, which I was
afraid I'd screw up.
* Incorporated the new crc32 library routines. Both BE and LE now use a
table. LE is faster, BE uses less space. It's trivial to make this
tradeoff now.

> * Still need init_crc32:
> 8139too, au1000_eth, fealnx, smc91c92_cs, xircom_tulip_cb, smc9194,
> via-rhine, winbond-840

Now that the BE functions use a table, yes.

> * lib/uuid.o needs to be in lib/Makefile's export-objs

Oops, good catch. I meant to submit uuid as a separate patch, but I'll
include it in the crc32-lib + efivars patches (it's small).

> * in init/cleanup_crc32, don't hold spinlock during kmalloc/kfree.
> Check out other refcounting schemes in the various fs/*.c files.

OK, hope this is better.

> * Add a Config.in entry, so that people can manually select to compile
> crc32.o as a module. This takes care of the 3rd party module case,
> the module that might for example have been built some time
> after the kernel itself was built.

OK. Turns out this then needs to change arch/$arch/config.in to add
lib/Config.in to the menus too. :-(

Here's today's pass at all this.
http://domsch.com/linux/patches/linux-2.4.13-pre3-crc32-lib-20011016.patch
http://domsch.com/linux/patches/linux-2.4.13-pre3-crc32-drivers-20011016.pat
ch
http://domsch.com/linux/patches/linux-2.4.13-pre3-gpt-20011016.patch
http://domsch.com/linux/patches/linux-2.4.13-pre3-efivars-20011016.patch

This is working on my x86 system with CONFIG_EFI_PARTITION enabled, so I
feel pretty good about at least the LE crc32 function. All the drivers that
could be built on x86 were, but I don't have hardware to test any of them,
nor any non-x86 platforms.

I'm not sure I got the init/cleanup right in all the modules. I tried to
call init_crc32() once only if/when we know the driver's init routine
actually found one or more cards. For the hassle of getting this right, I'm
tempted to make crc32.c have module_init/cleanup() that allocates the memory
unconditionally... It's only 2*1KB at most.

Feedback appreciated.

Thanks,
Matt

--
Matt Domsch
Sr. Software Engineer
Dell Linux Solutions
www.dell.com/linux
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