Re: [PATCH 12/14] x86_64 irq: Add constants for the reserved IRQ vectors.

[ebiederm@xmission.com (Eric W. Biederman)]

Pavel Machek <pavel@ucw.cz> writes:

> Hi!
>
>> For the ISA irqs we reserve 16 vectors.  This patch adds constants for
>> those vectors and modifies the code to use them.  Making the code a
>> little clearer and making it possible to move these vectors in the future.
>
>
>>  /*
>>   * Vectors 0x20-0x2f are used for ISA interrupts.
>>   */
>> +#define IRQ0_VECTOR		FIRST_EXTERNAL_VECTOR
>> +#define IRQ1_VECTOR		IRQ0_VECTOR + 1
>
> Maybe IRQ_VECTOR(1) would be similary readable, and would avoid 
>
>> +#define IRQ2_VECTOR		IRQ0_VECTOR + 2
>> +#define IRQ3_VECTOR		IRQ0_VECTOR + 3
>> +#define IRQ4_VECTOR		IRQ0_VECTOR + 4
>> +#define IRQ5_VECTOR		IRQ0_VECTOR + 5 
>> +#define IRQ6_VECTOR		IRQ0_VECTOR + 6
>> +#define IRQ7_VECTOR		IRQ0_VECTOR + 7
>> +#define IRQ8_VECTOR		IRQ0_VECTOR + 8
>> +#define IRQ9_VECTOR		IRQ0_VECTOR + 9
>> +#define IRQ10_VECTOR		IRQ0_VECTOR + 10
>> +#define IRQ11_VECTOR		IRQ0_VECTOR + 11
>> +#define IRQ12_VECTOR		IRQ0_VECTOR + 12
>> +#define IRQ13_VECTOR		IRQ0_VECTOR + 13
>> +#define IRQ14_VECTOR		IRQ0_VECTOR + 14
>> +#define IRQ15_VECTOR		IRQ0_VECTOR + 15
>
> ...these defines?

It would, and mostly I like it.  However, of the 1500+ possible irqs
exactly 16 have a reserved vector.  IRQ_VECTOR(N) does not convey
that in fact it conveys the opposite impression.

So I think the code is more maintainable with the distinct
definitions.

Eric
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/