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Date: Mon, 11 May 2020 02:07:21 -0500
From: Segher Boessenkool <segher@kernel.crashing.org>
To: Paul Mackerras <paulus@ozlabs.org>
Subject: Re: [PATCH RFC 3/4] powerpc/microwatt: Add early debug UART support
 for Microwatt
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References: <20200509050103.GA1464954@thinks.paulus.ozlabs.org>
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Cc: linuxppc-dev@ozlabs.org, Michael Neuling <mikey@neuling.org>,
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Hi!

On Sat, May 09, 2020 at 03:03:40PM +1000, Paul Mackerras wrote:
> +	__asm__ volatile("mtmsrd %3,0; ldcix %0,%1,%2; mtmsrd %4,0"
> +			 : "=r" (val) : "b" (potato_uart_base), "r" (offset),
> +			   "r" (msr & ~MSR_DR), "r" (msr));

That should be  "=&r"(val)  (an earlyclobber), because when %0 is
written, %4 will still be used later.

Looks fine otherwise.

Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>


Segher