diff mbox

ARM: keystone: remove hand-coded smc instruction

Message ID 51C4D9B7.5010109@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Santosh Shilimkar June 21, 2013, 10:54 p.m. UTC
On Friday 21 June 2013 05:41 PM, Arnd Bergmann wrote:
> On Friday 21 June 2013, Santosh Shilimkar wrote:
>>>
>> I was curious how you will fix that for a c file.
>> Just to be clear, I was planning to do that in 3.11-rcx/3.12
>> time. Let me know if it needs to be done earlier than that.
> 
> It breaks randconfig builds on arm-soc at the moment, so I'd
> like the fix as early as possible for 3.11.
> 
Ok, fix is at end of the email. Let me know if it makes
to pass both the builds now. I have build and boot tested
both ARM and THUMB2 builds on Keystone board.

Regards,
Santosh

From 05d6a5b6cad624fb3791e8c1f8eb7c774f0790d9 Mon Sep 17 00:00:00 2001
From: Santosh Shilimkar <santosh.shilimkar@ti.com>
Date: Fri, 21 Jun 2013 18:35:32 -0400
Subject: [PATCH] ARM: keystone: Move CPU bringup code to dedicated asm file

Because of inline asm usage in platsmp.c, smc instruction
creates build failure for ARM V6+V7 build where as using instruction
encoding for smc breaks the thumb2 build.

So move the code snippet to separate asm file and mark
it with 'armv7-a$(plus_sec)' to avoid any build issues.

Cc: Arnd Bergmann <arnd@arndb.de>

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
---
 arch/arm/mach-keystone/Makefile   |    6 +++++-
 arch/arm/mach-keystone/keystone.h |    6 ++++++
 arch/arm/mach-keystone/platsmp.c  |   15 +++------------
 arch/arm/mach-keystone/smc.S      |   29 +++++++++++++++++++++++++++++
 4 files changed, 43 insertions(+), 13 deletions(-)
 create mode 100644 arch/arm/mach-keystone/smc.S

Comments

tip-bot for Dave Martin June 25, 2013, 2:13 p.m. UTC | #1
On Fri, Jun 21, 2013 at 06:54:47PM -0400, Santosh Shilimkar wrote:
> On Friday 21 June 2013 05:41 PM, Arnd Bergmann wrote:
> > On Friday 21 June 2013, Santosh Shilimkar wrote:
> >>>
> >> I was curious how you will fix that for a c file.
> >> Just to be clear, I was planning to do that in 3.11-rcx/3.12
> >> time. Let me know if it needs to be done earlier than that.
> > 
> > It breaks randconfig builds on arm-soc at the moment, so I'd
> > like the fix as early as possible for 3.11.
> > 
> Ok, fix is at end of the email. Let me know if it makes
> to pass both the builds now. I have build and boot tested
> both ARM and THUMB2 builds on Keystone board.
> 
> Regards,
> Santosh
> 
> From 05d6a5b6cad624fb3791e8c1f8eb7c774f0790d9 Mon Sep 17 00:00:00 2001
> From: Santosh Shilimkar <santosh.shilimkar@ti.com>
> Date: Fri, 21 Jun 2013 18:35:32 -0400
> Subject: [PATCH] ARM: keystone: Move CPU bringup code to dedicated asm file
> 
> Because of inline asm usage in platsmp.c, smc instruction
> creates build failure for ARM V6+V7 build where as using instruction
> encoding for smc breaks the thumb2 build.
> 
> So move the code snippet to separate asm file and mark
> it with 'armv7-a$(plus_sec)' to avoid any build issues.
> 
> Cc: Arnd Bergmann <arnd@arndb.de>
> 
> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
> ---
>  arch/arm/mach-keystone/Makefile   |    6 +++++-
>  arch/arm/mach-keystone/keystone.h |    6 ++++++
>  arch/arm/mach-keystone/platsmp.c  |   15 +++------------
>  arch/arm/mach-keystone/smc.S      |   29 +++++++++++++++++++++++++++++
>  4 files changed, 43 insertions(+), 13 deletions(-)
>  create mode 100644 arch/arm/mach-keystone/smc.S
> 
> diff --git a/arch/arm/mach-keystone/Makefile b/arch/arm/mach-keystone/Makefile
> index 3f6b8ab..ddc52b0 100644
> --- a/arch/arm/mach-keystone/Makefile
> +++ b/arch/arm/mach-keystone/Makefile
> @@ -1,2 +1,6 @@
> -obj-y					:= keystone.o
> +obj-y					:= keystone.o smc.o
> +
> +plus_sec := $(call as-instr,.arch_extension sec,+sec)
> +AFLAGS_smc.o				:=-Wa,-march=armv7-a$(plus_sec)
> +
>  obj-$(CONFIG_SMP)			+= platsmp.o
> diff --git a/arch/arm/mach-keystone/keystone.h b/arch/arm/mach-keystone/keystone.h
> index 43a1b47..60bef9d 100644
> --- a/arch/arm/mach-keystone/keystone.h
> +++ b/arch/arm/mach-keystone/keystone.h
> @@ -11,7 +11,13 @@
>  #ifndef __KEYSTONE_H__
>  #define __KEYSTONE_H__
>  
> +#define KEYSTONE_MON_CPU_UP_IDX		0x00
> +
> +#ifndef __ASSEMBLER__
> +
>  extern struct smp_operations keystone_smp_ops;
>  extern void secondary_startup(void);
> +extern u32 keystone_cpu_smc(u32 command, u32 cpu, u32 addr);
>  
> +#endif /* __ASSEMBLER__ */
>  #endif /* __KEYSTONE_H__ */
> diff --git a/arch/arm/mach-keystone/platsmp.c b/arch/arm/mach-keystone/platsmp.c
> index 630ab3b..1d4181e 100644
> --- a/arch/arm/mach-keystone/platsmp.c
> +++ b/arch/arm/mach-keystone/platsmp.c
> @@ -30,18 +30,9 @@ static int __cpuinit keystone_smp_boot_secondary(unsigned int cpu,
>  	pr_debug("keystone-smp: booting cpu %d, vector %08lx\n",
>  		 cpu, start);
>  
> -	asm volatile (
> -		"mov    r0, #0\n"	/* power on cmd	*/
> -		"mov    r1, %1\n"	/* cpu		*/
> -		"mov    r2, %2\n"	/* start	*/
> -		".inst  0xe1600070\n"	/* smc #0	*/
> -		"mov    %0, r0\n"
> -		: "=r" (error)
> -		: "r"(cpu), "r"(start)
> -		: "cc", "r0", "r1", "r2", "memory"
> -	);
> -
> -	pr_debug("keystone-smp: monitor returned %d\n", error);
> +	error = keystone_cpu_smc(KEYSTONE_MON_CPU_UP_IDX, cpu, start);
> +	if (error)
> +		pr_err("CPU %d bringup failed with %d\n", cpu, error);
>  
>  	return error;
>  }
> diff --git a/arch/arm/mach-keystone/smc.S b/arch/arm/mach-keystone/smc.S
> new file mode 100644
> index 0000000..9b9e4f7
> --- /dev/null
> +++ b/arch/arm/mach-keystone/smc.S
> @@ -0,0 +1,29 @@
> +/*
> + * Keystone Secure APIs
> + *
> + * Copyright (C) 2013 Texas Instruments, Inc.
> + * 	Santosh Shilimkar <santosh.shilimkar@ti.com>
> + *
> + * This program is free software,you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/linkage.h>
> +
> +/**
> + * u32 keystone_cpu_smc(u32 command, u32 cpu, u32 addr)
> + *
> + * Low level CPU monitor API
> + * @command:	Monitor command.
> + * @cpu:	CPU Number
> + * @addr:	Kernel jump address for boot CPU
> + *
> + * Return: Non zero value on failure
> + */

Oops, looks like I missed the final mail on this thread.  Ignore my
previous mail.

I still think it would be a good idea to try to consolidate all these
trivial SMC wrappers, but this remains debatable.



Anyway, this looks like it should work, except:

> +ENTRY(keystone_cpu_smc)
> +	stmfd   sp!, {r4-r12, lr}
> +	smc	#0
> +	dsb

What's this DSB for?  (You didn't have it in the inline asm version)

> +	ldmfd   sp!, {r4-r12, pc}
> +ENDPROC(keystone_cpu_smc)

r12 is caller-save btw; you don't need to preserve it.

Cheers
---Dave
Santosh Shilimkar June 25, 2013, 2:27 p.m. UTC | #2
On Tuesday 25 June 2013 10:13 AM, Dave Martin wrote:
> On Fri, Jun 21, 2013 at 06:54:47PM -0400, Santosh Shilimkar wrote:
>> On Friday 21 June 2013 05:41 PM, Arnd Bergmann wrote:
>>> On Friday 21 June 2013, Santosh Shilimkar wrote:
>>>>>
>>>> I was curious how you will fix that for a c file.
>>>> Just to be clear, I was planning to do that in 3.11-rcx/3.12
>>>> time. Let me know if it needs to be done earlier than that.
>>>
>>> It breaks randconfig builds on arm-soc at the moment, so I'd
>>> like the fix as early as possible for 3.11.
>>>
>> Ok, fix is at end of the email. Let me know if it makes
>> to pass both the builds now. I have build and boot tested
>> both ARM and THUMB2 builds on Keystone board.
>>
>> Regards,
>> Santosh
>>
>> From 05d6a5b6cad624fb3791e8c1f8eb7c774f0790d9 Mon Sep 17 00:00:00 2001
>> From: Santosh Shilimkar <santosh.shilimkar@ti.com>
>> Date: Fri, 21 Jun 2013 18:35:32 -0400
>> Subject: [PATCH] ARM: keystone: Move CPU bringup code to dedicated asm file
>>
>> Because of inline asm usage in platsmp.c, smc instruction
>> creates build failure for ARM V6+V7 build where as using instruction
>> encoding for smc breaks the thumb2 build.
>>
>> So move the code snippet to separate asm file and mark
>> it with 'armv7-a$(plus_sec)' to avoid any build issues.
>>
>> Cc: Arnd Bergmann <arnd@arndb.de>
>>
>> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
>> ---

[..]

>> diff --git a/arch/arm/mach-keystone/smc.S b/arch/arm/mach-keystone/smc.S
>> new file mode 100644
>> index 0000000..9b9e4f7
>> --- /dev/null
>> +++ b/arch/arm/mach-keystone/smc.S
>> @@ -0,0 +1,29 @@
>> +/*
>> + * Keystone Secure APIs
>> + *
>> + * Copyright (C) 2013 Texas Instruments, Inc.
>> + * 	Santosh Shilimkar <santosh.shilimkar@ti.com>
>> + *
>> + * This program is free software,you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + */
>> +
>> +#include <linux/linkage.h>
>> +
>> +/**
>> + * u32 keystone_cpu_smc(u32 command, u32 cpu, u32 addr)
>> + *
>> + * Low level CPU monitor API
>> + * @command:	Monitor command.
>> + * @cpu:	CPU Number
>> + * @addr:	Kernel jump address for boot CPU
>> + *
>> + * Return: Non zero value on failure
>> + */
> 
> Oops, looks like I missed the final mail on this thread.  Ignore my
> previous mail.
> 
> I still think it would be a good idea to try to consolidate all these
> trivial SMC wrappers, but this remains debatable.
> 
> 
> 
> Anyway, this looks like it should work, except:
> 
>> +ENTRY(keystone_cpu_smc)
>> +	stmfd   sp!, {r4-r12, lr}
>> +	smc	#0
>> +	dsb
> 
> What's this DSB for?  (You didn't have it in the inline asm version)
>
Just to drain the write buffer before resuming on non-secure side.
I actually added it while moving it to asm file.
 
>> +	ldmfd   sp!, {r4-r12, pc}
>> +ENDPROC(keystone_cpu_smc)
> 
> r12 is caller-save btw; you don't need to preserve it.
> 
Indeed. Will update it while adding some more SMC APIs.
Its not harmful as such for now.

Regards,
Santosh
tip-bot for Dave Martin June 25, 2013, 2:32 p.m. UTC | #3
On Tue, Jun 25, 2013 at 10:27:11AM -0400, Santosh Shilimkar wrote:
> On Tuesday 25 June 2013 10:13 AM, Dave Martin wrote:
> > On Fri, Jun 21, 2013 at 06:54:47PM -0400, Santosh Shilimkar wrote:
> >> On Friday 21 June 2013 05:41 PM, Arnd Bergmann wrote:
> >>> On Friday 21 June 2013, Santosh Shilimkar wrote:
> >>>>>
> >>>> I was curious how you will fix that for a c file.
> >>>> Just to be clear, I was planning to do that in 3.11-rcx/3.12
> >>>> time. Let me know if it needs to be done earlier than that.
> >>>
> >>> It breaks randconfig builds on arm-soc at the moment, so I'd
> >>> like the fix as early as possible for 3.11.
> >>>
> >> Ok, fix is at end of the email. Let me know if it makes
> >> to pass both the builds now. I have build and boot tested
> >> both ARM and THUMB2 builds on Keystone board.
> >>
> >> Regards,
> >> Santosh
> >>
> >> From 05d6a5b6cad624fb3791e8c1f8eb7c774f0790d9 Mon Sep 17 00:00:00 2001
> >> From: Santosh Shilimkar <santosh.shilimkar@ti.com>
> >> Date: Fri, 21 Jun 2013 18:35:32 -0400
> >> Subject: [PATCH] ARM: keystone: Move CPU bringup code to dedicated asm file
> >>
> >> Because of inline asm usage in platsmp.c, smc instruction
> >> creates build failure for ARM V6+V7 build where as using instruction
> >> encoding for smc breaks the thumb2 build.
> >>
> >> So move the code snippet to separate asm file and mark
> >> it with 'armv7-a$(plus_sec)' to avoid any build issues.
> >>
> >> Cc: Arnd Bergmann <arnd@arndb.de>
> >>
> >> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
> >> ---
> 
> [..]
> 
> >> diff --git a/arch/arm/mach-keystone/smc.S b/arch/arm/mach-keystone/smc.S
> >> new file mode 100644
> >> index 0000000..9b9e4f7
> >> --- /dev/null
> >> +++ b/arch/arm/mach-keystone/smc.S
> >> @@ -0,0 +1,29 @@
> >> +/*
> >> + * Keystone Secure APIs
> >> + *
> >> + * Copyright (C) 2013 Texas Instruments, Inc.
> >> + * 	Santosh Shilimkar <santosh.shilimkar@ti.com>
> >> + *
> >> + * This program is free software,you can redistribute it and/or modify
> >> + * it under the terms of the GNU General Public License version 2 as
> >> + * published by the Free Software Foundation.
> >> + */
> >> +
> >> +#include <linux/linkage.h>
> >> +
> >> +/**
> >> + * u32 keystone_cpu_smc(u32 command, u32 cpu, u32 addr)
> >> + *
> >> + * Low level CPU monitor API
> >> + * @command:	Monitor command.
> >> + * @cpu:	CPU Number
> >> + * @addr:	Kernel jump address for boot CPU
> >> + *
> >> + * Return: Non zero value on failure
> >> + */
> > 
> > Oops, looks like I missed the final mail on this thread.  Ignore my
> > previous mail.
> > 
> > I still think it would be a good idea to try to consolidate all these
> > trivial SMC wrappers, but this remains debatable.
> > 
> > 
> > 
> > Anyway, this looks like it should work, except:
> > 
> >> +ENTRY(keystone_cpu_smc)
> >> +	stmfd   sp!, {r4-r12, lr}
> >> +	smc	#0
> >> +	dsb
> > 
> > What's this DSB for?  (You didn't have it in the inline asm version)
> >
> Just to drain the write buffer before resuming on non-secure side.

Why do you need to do that?

> I actually added it while moving it to asm file.
>  
> >> +	ldmfd   sp!, {r4-r12, pc}
> >> +ENDPROC(keystone_cpu_smc)
> > 
> > r12 is caller-save btw; you don't need to preserve it.
> > 
> Indeed. Will update it while adding some more SMC APIs.
> Its not harmful as such for now.

If you could change that as soon as you make another modification to
this file, that would be appreciated.  These code snippets get
cut and pasted recklessly.

Cheers
---Dave
Santosh Shilimkar June 25, 2013, 2:40 p.m. UTC | #4
On Tuesday 25 June 2013 10:32 AM, Dave Martin wrote:
> On Tue, Jun 25, 2013 at 10:27:11AM -0400, Santosh Shilimkar wrote:
>> On Tuesday 25 June 2013 10:13 AM, Dave Martin wrote:
>>> On Fri, Jun 21, 2013 at 06:54:47PM -0400, Santosh Shilimkar wrote:
>>>> On Friday 21 June 2013 05:41 PM, Arnd Bergmann wrote:
>>>>> On Friday 21 June 2013, Santosh Shilimkar wrote:
>>>>>>>
>>>>>> I was curious how you will fix that for a c file.
>>>>>> Just to be clear, I was planning to do that in 3.11-rcx/3.12
>>>>>> time. Let me know if it needs to be done earlier than that.
>>>>>
>>>>> It breaks randconfig builds on arm-soc at the moment, so I'd
>>>>> like the fix as early as possible for 3.11.
>>>>>
>>>> Ok, fix is at end of the email. Let me know if it makes
>>>> to pass both the builds now. I have build and boot tested
>>>> both ARM and THUMB2 builds on Keystone board.
>>>>
>>>> Regards,
>>>> Santosh
>>>>
>>>> From 05d6a5b6cad624fb3791e8c1f8eb7c774f0790d9 Mon Sep 17 00:00:00 2001
>>>> From: Santosh Shilimkar <santosh.shilimkar@ti.com>
>>>> Date: Fri, 21 Jun 2013 18:35:32 -0400
>>>> Subject: [PATCH] ARM: keystone: Move CPU bringup code to dedicated asm file
>>>>
>>>> Because of inline asm usage in platsmp.c, smc instruction
>>>> creates build failure for ARM V6+V7 build where as using instruction
>>>> encoding for smc breaks the thumb2 build.
>>>>
>>>> So move the code snippet to separate asm file and mark
>>>> it with 'armv7-a$(plus_sec)' to avoid any build issues.
>>>>
>>>> Cc: Arnd Bergmann <arnd@arndb.de>
>>>>
>>>> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
>>>> ---
>>
>> [..]
>>
>>>> diff --git a/arch/arm/mach-keystone/smc.S b/arch/arm/mach-keystone/smc.S
>>>> new file mode 100644
>>>> index 0000000..9b9e4f7
>>>> --- /dev/null
>>>> +++ b/arch/arm/mach-keystone/smc.S
>>>> @@ -0,0 +1,29 @@
>>>> +/*
>>>> + * Keystone Secure APIs
>>>> + *
>>>> + * Copyright (C) 2013 Texas Instruments, Inc.
>>>> + * 	Santosh Shilimkar <santosh.shilimkar@ti.com>
>>>> + *
>>>> + * This program is free software,you can redistribute it and/or modify
>>>> + * it under the terms of the GNU General Public License version 2 as
>>>> + * published by the Free Software Foundation.
>>>> + */
>>>> +
>>>> +#include <linux/linkage.h>
>>>> +
>>>> +/**
>>>> + * u32 keystone_cpu_smc(u32 command, u32 cpu, u32 addr)
>>>> + *
>>>> + * Low level CPU monitor API
>>>> + * @command:	Monitor command.
>>>> + * @cpu:	CPU Number
>>>> + * @addr:	Kernel jump address for boot CPU
>>>> + *
>>>> + * Return: Non zero value on failure
>>>> + */
>>>
>>> Oops, looks like I missed the final mail on this thread.  Ignore my
>>> previous mail.
>>>
>>> I still think it would be a good idea to try to consolidate all these
>>> trivial SMC wrappers, but this remains debatable.
>>>
>>>
>>>
>>> Anyway, this looks like it should work, except:
>>>
>>>> +ENTRY(keystone_cpu_smc)
>>>> +	stmfd   sp!, {r4-r12, lr}
>>>> +	smc	#0
>>>> +	dsb
>>>
>>> What's this DSB for?  (You didn't have it in the inline asm version)
>>>
>> Just to drain the write buffer before resuming on non-secure side.
> 
> Why do you need to do that?
> 
To commit any secure side pending writes. I don't remember exactly the
issues but I remember facing issues in power management sequencing with
SMC calls in between. That time a dsb did the trick. In fact I use to
keep 1 before SMC and 1 after. 

>> I actually added it while moving it to asm file.
>>  
>>>> +	ldmfd   sp!, {r4-r12, pc}
>>>> +ENDPROC(keystone_cpu_smc)
>>>
>>> r12 is caller-save btw; you don't need to preserve it.
>>>
>> Indeed. Will update it while adding some more SMC APIs.
>> Its not harmful as such for now.
> 
> If you could change that as soon as you make another modification to
> this file, that would be appreciated.  These code snippets get
> cut and pasted recklessly.
> 
Yep. Thats what I mean.

Regards,
Santosh
tip-bot for Dave Martin June 25, 2013, 3:39 p.m. UTC | #5
On Tue, Jun 25, 2013 at 10:40:57AM -0400, Santosh Shilimkar wrote:
> On Tuesday 25 June 2013 10:32 AM, Dave Martin wrote:
> > On Tue, Jun 25, 2013 at 10:27:11AM -0400, Santosh Shilimkar wrote:
> >> On Tuesday 25 June 2013 10:13 AM, Dave Martin wrote:
> >>> On Fri, Jun 21, 2013 at 06:54:47PM -0400, Santosh Shilimkar wrote:
> >>>> On Friday 21 June 2013 05:41 PM, Arnd Bergmann wrote:
> >>>>> On Friday 21 June 2013, Santosh Shilimkar wrote:
> >>>>>>>
> >>>>>> I was curious how you will fix that for a c file.
> >>>>>> Just to be clear, I was planning to do that in 3.11-rcx/3.12
> >>>>>> time. Let me know if it needs to be done earlier than that.
> >>>>>
> >>>>> It breaks randconfig builds on arm-soc at the moment, so I'd
> >>>>> like the fix as early as possible for 3.11.
> >>>>>
> >>>> Ok, fix is at end of the email. Let me know if it makes
> >>>> to pass both the builds now. I have build and boot tested
> >>>> both ARM and THUMB2 builds on Keystone board.
> >>>>
> >>>> Regards,
> >>>> Santosh
> >>>>
> >>>> From 05d6a5b6cad624fb3791e8c1f8eb7c774f0790d9 Mon Sep 17 00:00:00 2001
> >>>> From: Santosh Shilimkar <santosh.shilimkar@ti.com>
> >>>> Date: Fri, 21 Jun 2013 18:35:32 -0400
> >>>> Subject: [PATCH] ARM: keystone: Move CPU bringup code to dedicated asm file
> >>>>
> >>>> Because of inline asm usage in platsmp.c, smc instruction
> >>>> creates build failure for ARM V6+V7 build where as using instruction
> >>>> encoding for smc breaks the thumb2 build.
> >>>>
> >>>> So move the code snippet to separate asm file and mark
> >>>> it with 'armv7-a$(plus_sec)' to avoid any build issues.
> >>>>
> >>>> Cc: Arnd Bergmann <arnd@arndb.de>
> >>>>
> >>>> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
> >>>> ---
> >>
> >> [..]
> >>
> >>>> diff --git a/arch/arm/mach-keystone/smc.S b/arch/arm/mach-keystone/smc.S
> >>>> new file mode 100644
> >>>> index 0000000..9b9e4f7
> >>>> --- /dev/null
> >>>> +++ b/arch/arm/mach-keystone/smc.S
> >>>> @@ -0,0 +1,29 @@
> >>>> +/*
> >>>> + * Keystone Secure APIs
> >>>> + *
> >>>> + * Copyright (C) 2013 Texas Instruments, Inc.
> >>>> + * 	Santosh Shilimkar <santosh.shilimkar@ti.com>
> >>>> + *
> >>>> + * This program is free software,you can redistribute it and/or modify
> >>>> + * it under the terms of the GNU General Public License version 2 as
> >>>> + * published by the Free Software Foundation.
> >>>> + */
> >>>> +
> >>>> +#include <linux/linkage.h>
> >>>> +
> >>>> +/**
> >>>> + * u32 keystone_cpu_smc(u32 command, u32 cpu, u32 addr)
> >>>> + *
> >>>> + * Low level CPU monitor API
> >>>> + * @command:	Monitor command.
> >>>> + * @cpu:	CPU Number
> >>>> + * @addr:	Kernel jump address for boot CPU
> >>>> + *
> >>>> + * Return: Non zero value on failure
> >>>> + */
> >>>
> >>> Oops, looks like I missed the final mail on this thread.  Ignore my
> >>> previous mail.
> >>>
> >>> I still think it would be a good idea to try to consolidate all these
> >>> trivial SMC wrappers, but this remains debatable.
> >>>
> >>>
> >>>
> >>> Anyway, this looks like it should work, except:
> >>>
> >>>> +ENTRY(keystone_cpu_smc)
> >>>> +	stmfd   sp!, {r4-r12, lr}
> >>>> +	smc	#0
> >>>> +	dsb
> >>>
> >>> What's this DSB for?  (You didn't have it in the inline asm version)
> >>>
> >> Just to drain the write buffer before resuming on non-secure side.
> > 
> > Why do you need to do that?
> > 
> To commit any secure side pending writes. I don't remember exactly the
> issues but I remember facing issues in power management sequencing with
> SMC calls in between. That time a dsb did the trick. In fact I use to
> keep 1 before SMC and 1 after. 

Can we at least have a comment (as recommended in
Documentation/development-process/4.Coding)?

We don't want other people reading this and concluding that SMC always
needs barriers -- in general, this shouldn't be necessary and could
indicate bugs lurking somewhere.

Cheers
---Dave
Santosh Shilimkar June 25, 2013, 3:51 p.m. UTC | #6
On Tuesday 25 June 2013 11:39 AM, Dave Martin wrote:
> On Tue, Jun 25, 2013 at 10:40:57AM -0400, Santosh Shilimkar wrote:
>> On Tuesday 25 June 2013 10:32 AM, Dave Martin wrote:
>>> On Tue, Jun 25, 2013 at 10:27:11AM -0400, Santosh Shilimkar wrote:
>>>> On Tuesday 25 June 2013 10:13 AM, Dave Martin wrote:
>>>>> On Fri, Jun 21, 2013 at 06:54:47PM -0400, Santosh Shilimkar wrote:
>>>>>> On Friday 21 June 2013 05:41 PM, Arnd Bergmann wrote:
>>>>>>> On Friday 21 June 2013, Santosh Shilimkar wrote:
>>>>>>>>>
>>>>>>>> I was curious how you will fix that for a c file.
>>>>>>>> Just to be clear, I was planning to do that in 3.11-rcx/3.12
>>>>>>>> time. Let me know if it needs to be done earlier than that.
>>>>>>>
>>>>>>> It breaks randconfig builds on arm-soc at the moment, so I'd
>>>>>>> like the fix as early as possible for 3.11.
>>>>>>>
>>>>>> Ok, fix is at end of the email. Let me know if it makes
>>>>>> to pass both the builds now. I have build and boot tested
>>>>>> both ARM and THUMB2 builds on Keystone board.
>>>>>>
>>>>>> Regards,
>>>>>> Santosh
>>>>>>
>>>>>> From 05d6a5b6cad624fb3791e8c1f8eb7c774f0790d9 Mon Sep 17 00:00:00 2001
>>>>>> From: Santosh Shilimkar <santosh.shilimkar@ti.com>
>>>>>> Date: Fri, 21 Jun 2013 18:35:32 -0400
>>>>>> Subject: [PATCH] ARM: keystone: Move CPU bringup code to dedicated asm file
>>>>>>
>>>>>> Because of inline asm usage in platsmp.c, smc instruction
>>>>>> creates build failure for ARM V6+V7 build where as using instruction
>>>>>> encoding for smc breaks the thumb2 build.
>>>>>>
>>>>>> So move the code snippet to separate asm file and mark
>>>>>> it with 'armv7-a$(plus_sec)' to avoid any build issues.
>>>>>>
>>>>>> Cc: Arnd Bergmann <arnd@arndb.de>
>>>>>>
>>>>>> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
>>>>>> ---

[..]

>>>>> Anyway, this looks like it should work, except:
>>>>>
>>>>>> +ENTRY(keystone_cpu_smc)
>>>>>> +	stmfd   sp!, {r4-r12, lr}
>>>>>> +	smc	#0
>>>>>> +	dsb
>>>>>
>>>>> What's this DSB for?  (You didn't have it in the inline asm version)
>>>>>
>>>> Just to drain the write buffer before resuming on non-secure side.
>>>
>>> Why do you need to do that?
>>>
>> To commit any secure side pending writes. I don't remember exactly the
>> issues but I remember facing issues in power management sequencing with
>> SMC calls in between. That time a dsb did the trick. In fact I use to
>> keep 1 before SMC and 1 after. 
> 
> Can we at least have a comment (as recommended in
> Documentation/development-process/4.Coding)?
> 
> We don't want other people reading this and concluding that SMC always
> needs barriers -- in general, this shouldn't be necessary and could
> indicate bugs lurking somewhere.
> 
Agree. Comment should have been there to avoid confusion. Will do.

Regards,
Santosh
diff mbox

Patch

diff --git a/arch/arm/mach-keystone/Makefile b/arch/arm/mach-keystone/Makefile
index 3f6b8ab..ddc52b0 100644
--- a/arch/arm/mach-keystone/Makefile
+++ b/arch/arm/mach-keystone/Makefile
@@ -1,2 +1,6 @@ 
-obj-y					:= keystone.o
+obj-y					:= keystone.o smc.o
+
+plus_sec := $(call as-instr,.arch_extension sec,+sec)
+AFLAGS_smc.o				:=-Wa,-march=armv7-a$(plus_sec)
+
 obj-$(CONFIG_SMP)			+= platsmp.o
diff --git a/arch/arm/mach-keystone/keystone.h b/arch/arm/mach-keystone/keystone.h
index 43a1b47..60bef9d 100644
--- a/arch/arm/mach-keystone/keystone.h
+++ b/arch/arm/mach-keystone/keystone.h
@@ -11,7 +11,13 @@ 
 #ifndef __KEYSTONE_H__
 #define __KEYSTONE_H__
 
+#define KEYSTONE_MON_CPU_UP_IDX		0x00
+
+#ifndef __ASSEMBLER__
+
 extern struct smp_operations keystone_smp_ops;
 extern void secondary_startup(void);
+extern u32 keystone_cpu_smc(u32 command, u32 cpu, u32 addr);
 
+#endif /* __ASSEMBLER__ */
 #endif /* __KEYSTONE_H__ */
diff --git a/arch/arm/mach-keystone/platsmp.c b/arch/arm/mach-keystone/platsmp.c
index 630ab3b..1d4181e 100644
--- a/arch/arm/mach-keystone/platsmp.c
+++ b/arch/arm/mach-keystone/platsmp.c
@@ -30,18 +30,9 @@  static int __cpuinit keystone_smp_boot_secondary(unsigned int cpu,
 	pr_debug("keystone-smp: booting cpu %d, vector %08lx\n",
 		 cpu, start);
 
-	asm volatile (
-		"mov    r0, #0\n"	/* power on cmd	*/
-		"mov    r1, %1\n"	/* cpu		*/
-		"mov    r2, %2\n"	/* start	*/
-		".inst  0xe1600070\n"	/* smc #0	*/
-		"mov    %0, r0\n"
-		: "=r" (error)
-		: "r"(cpu), "r"(start)
-		: "cc", "r0", "r1", "r2", "memory"
-	);
-
-	pr_debug("keystone-smp: monitor returned %d\n", error);
+	error = keystone_cpu_smc(KEYSTONE_MON_CPU_UP_IDX, cpu, start);
+	if (error)
+		pr_err("CPU %d bringup failed with %d\n", cpu, error);
 
 	return error;
 }
diff --git a/arch/arm/mach-keystone/smc.S b/arch/arm/mach-keystone/smc.S
new file mode 100644
index 0000000..9b9e4f7
--- /dev/null
+++ b/arch/arm/mach-keystone/smc.S
@@ -0,0 +1,29 @@ 
+/*
+ * Keystone Secure APIs
+ *
+ * Copyright (C) 2013 Texas Instruments, Inc.
+ * 	Santosh Shilimkar <santosh.shilimkar@ti.com>
+ *
+ * This program is free software,you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+
+/**
+ * u32 keystone_cpu_smc(u32 command, u32 cpu, u32 addr)
+ *
+ * Low level CPU monitor API
+ * @command:	Monitor command.
+ * @cpu:	CPU Number
+ * @addr:	Kernel jump address for boot CPU
+ *
+ * Return: Non zero value on failure
+ */
+ENTRY(keystone_cpu_smc)
+	stmfd   sp!, {r4-r12, lr}
+	smc	#0
+	dsb
+	ldmfd   sp!, {r4-r12, pc}
+ENDPROC(keystone_cpu_smc)