Re: [PATCH] intel-x86 model config cleanup

Jeff Garzik
2002-05-29T23:14:32Z

J.A. Magallon wrote:

>On 2002.05.30 Jeff Garzik wrote:
>
>
>>The basic thing to remember is that "generic_foo" or "cpu_intel_foo"
>>options should very rarely, if ever, appear in the config.in or sources.
>>We simply want to use the generic or cpu-specific user selection to
>>determine (a) compiler flags, (b) CONFIG_xxx symbols for specific CPU
>>features and optimizations, [like CONFIG_X86_F00F_BUG] and maybe (c)
>>enable and disable CPU-specific drivers. (c) will be a special case,
>>since very few drivers should require a specific CPU type... but some
>>drivers simply don't work on 386.
>>
>>
>>
>
>Grep on the tree showed this:
>
>drivers/char/serial.c:
>
>#if defined(__i386__) && (defined(CONFIG_M386) || defined(CONFIG_M486))
>#define SERIAL_INLINE
>#endif
>
>include/asm-i386/processor.h:
>
>/* Prefetch instructions for Pentium III and AMD Athlon */
>#ifdef CONFIG_MPENTIUMIII
>
>#define ARCH_HAS_PREFETCH
>
>

ARCH_HAS_foo are feature symbols, just like CONFIG_X86_F00F_BUG, so
those are fine. They're just cross-architecture, but perform the same
task: feature dis/enabling. For the serial example, you'd just need to
make sure the net effect of the code is the same, both before and after
an x86 config.in cleanup.

Jeff