From: santosh.shilimkar@ti•com (Santosh Shilimkar)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] ARM: keystone: remove hand-coded smc instruction
Date: Tue, 25 Jun 2013 10:10:45 -0400 [thread overview]
Message-ID: <51C9A4E5.8050505@ti.com> (raw)
In-Reply-To: <20130625140701.GB2327@linaro.org>
On Tuesday 25 June 2013 10:07 AM, Dave Martin wrote:
> On Fri, Jun 21, 2013 at 04:49:30PM -0400, Santosh Shilimkar wrote:
>> 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 <arnd@arndb•de>
>>>> Cc: Santosh Shilimkar <santosh.shilimkar@ti•com>
>>>>
>>>> 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.
>
> I think the correct way to fix this is to use ".arch_extension sec" and "smc" in
> the C inline asm, and put
>
> CFLAGS_platsmp.o := -march=armv7-a
>
> in arch/arm/mach-keystone/Makefile
>
> This approach is followed in a few other places.
>
>
> Or put the SMC in a separate .S file with suitable AFLAGS if not on a
> performance-critical hot path (for boot_secondary() it doesn't sounds
> like a problem).
>
Yep. Separate .S file patch is already submitted. Thanks
Regards,
Santosh
prev parent reply other threads:[~2013-06-25 14:10 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-21 20:28 [PATCH] ARM: keystone: remove hand-coded smc instruction Arnd Bergmann
2013-06-21 20:35 ` Arnd Bergmann
2013-06-21 20:49 ` Santosh Shilimkar
2013-06-21 21:13 ` Arnd Bergmann
2013-06-21 21:20 ` Santosh Shilimkar
2013-06-21 21:41 ` Arnd Bergmann
2013-06-21 22:54 ` Santosh Shilimkar
2013-06-25 14:13 ` Dave Martin
2013-06-25 14:27 ` Santosh Shilimkar
2013-06-25 14:32 ` Dave Martin
2013-06-25 14:40 ` Santosh Shilimkar
2013-06-25 15:39 ` Dave Martin
2013-06-25 15:51 ` Santosh Shilimkar
2013-06-25 14:07 ` Dave Martin
2013-06-25 14:10 ` Santosh Shilimkar [this message]
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