Re: [PATCH] ppc32: Add support for Freescale e200 (Book-E) core

From: Eugene Surovegin
Date: Wed Jun 22 2005 - 17:13:55 EST


On Wed, Jun 22, 2005 at 03:41:09PM -0500, Kumar Gala wrote:

[snip]

> +#ifdef CONFIG_E200
> +#define DEBUG_EXCEPTION \
> + START_EXCEPTION(Debug); \
> + DEBUG_EXCEPTION_PROLOG; \
> + \
> + /* \
> + * If there is a single step or branch-taken exception in an \
> + * exception entry sequence, it was probably meant to apply to \
> + * the code where the exception occurred (since exception entry \
> + * doesn't turn off DE automatically). We simulate the effect \
> + * of turning off DE on entry to an exception handler by turning \
> + * off DE in the CSRR1 value and clearing the debug status. \
> + */ \
> + mfspr r10,SPRN_DBSR; /* check single-step/branch taken */ \
> + andis. r10,r10,DBSR_IC@h; \
> + beq+ 2f; \
> + \
> + lis r10,KERNELBASE@h; /* check if exception in vectors */ \
> + ori r10,r10,KERNELBASE@l; \

I think we can get rid of one instruction here :)

--
Eugene


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