Subject: [PATCH] ARM: keystone: remove hand-coded smc instruction

From: [email-masked] (Santosh Shilimkar)
Date: Fri, 21 Jun 2013 16:49:30 -0400

On Friday 21 June 2013 04:35 PM, Arnd Bergmann wrote:
> On Friday 21 June 2013, Arnd Bergmann wrote:
>> This lets us build keystone with CONFIG_THUMB2_KERNEL enabled,
>> without the patch we get this error:
>>
>> Error: cannot determine Thumb instruction size. Use .inst.n/.inst.w instead
>>
>> This follows the same change for all other platforms done
>> earlier.
>>
>> Signed-off-by: Arnd Bergmann <[email-masked]>
>> Cc: Santosh Shilimkar <[email-masked]>
>>
>> diff --git a/arch/arm/mach-keystone/platsmp.c b/arch/arm/mach-keystone/platsmp.c
>> index 630ab3bd..1800c33 100644
>> --- a/arch/arm/mach-keystone/platsmp.c
>> +++ b/arch/arm/mach-keystone/platsmp.c
>> @@ -34,7 +34,7 @@ static int __cpuinit keystone_smp_boot_secondary(unsigned int cpu,
>>  		"mov    r0, #0\n"	/* power on cmd	*/
>>  		"mov    r1, %1\n"	/* cpu		*/
>>  		"mov    r2, %2\n"	/* start	*/
>> -		".inst  0xe1600070\n"	/* smc #0	*/
>> +		"smc	#0\n"		/* smc #0	*/
>>  		"mov    %0, r0\n"
>>  		: "=r" (error)
>>  		: "r"(cpu), "r"(start)
> 
> Ah, damm, now I get this error for building an ARMv6+ARMv7 combined kernel:
> 
> /tmp/ccSWHCik.s:55: Error: selected processor does not support ARM mode `smc #0'
> 
> I'll add a -march=armv7-a gcc flag as well.
> 
I was just typing about the error. I started with smc first but then
hit the below one which lead me to write an opcode. I couldn't compile c file
for v7 only build and hence letf it in encoded format.

I will be moving this code to separate asm file along with other smc
API support.

Regards,
Santosh