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Date: Wed, 22 Jun 2005 14:58:18 -0700
From: Eugene Surovegin <ebs@ebshome.net>
To: Kumar Gala <galak@freescale.com>
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Cc: Andrew Morton <akpm@osdl.org>, linux-kernel@vger.kernel.org,
	linuxppc-embedded <linuxppc-embedded@ozlabs.org>
Subject: Re: [PATCH] ppc32: Add support for Freescale e200 (Book-E) core
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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