implementation of software suspend on MIPS.

implementation of software suspend on MIPS.

[Hyon Lim]

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Hello.  I need a help for my implementation work on MIPS software suspend.
From 3month ago, I've been coding software suspend(swsusp) on MIPS arch.
I'm developing with MIPS32 4KEc embedded processor for digital appliance.

Swsusp has two procedure. the one is suspending procedure and other one is
resume procedure.
Yesterday, I confirmed suspending procedure working.
This is a porting guide of swsusp (
http://tree.celinuxforum.org/CelfPubWiki/SwSuspendPortingNotes)
I refered this article.

The problem I faced is assembly language for MIPS.
Of course, there are many manuals for this work but, I need a help from MIPS
expert.

This pseudo code should be implemented by MIPS asm.

        for (j = nr_copy_pages; j>0; j--) {
            src = pagedir_nosave[j].src;
            dst = pagedir_nosave[j].dst;
            for (i=0;i<1024;i++) {
                *dst++ = *src++;
            }
        }

nr_copy_pages is unsigned long variable.
and pagedir_nosave is a
suspend_pagedir_t<http://lxr.linux.no/source/kernel/power/ident?v=2.6.10;i=suspend_pagedir_t>type
structure array(pointer). (you can refer following url. Line 101. :
http://lxr.linux.no/source/kernel/power/swsusp.c?v=2.6.10)
code skeleton or useful material will be welcomed. (whatever you have.)

The second problem is
" which register should be prevented? "

I saved $v0-v1. $a0-$a3. $t0-t7. $s0-s7. $t8-t9. $gp,sp,fp,ra.

-- 
Hyon Lim (임현)
Mobile. 010-8212-1240 (Intl' Call : +82-10-8212-1240)
Fax. 032-232-0578 (Intl' Available)
Homepage : http://www.alexlab.net
Blog : http://www.alexlab.net/blog

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RE: implementation of software suspend on MIPS.

[Uhler, Mike]

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I've asked our software team to follow up with you on your questions.
 
/gmu
---
Michael Uhler, VP Architecture, Software and Platform Engineering
MIPS Technologies, Inc.   Email: uhler AT mips.com
1225 Charleston Road      Voice:  (650)567-5025
Mountain View, CA 94043
  


________________________________

	From: linux-mips-bounce@linux-mips.org [mailto:linux-mips-bounce@linux-mips.org] On Behalf Of Hyon Lim
	Sent: Tuesday, October 30, 2007 12:13 PM
	To: linux-mips@linux-mips.org
	Subject:  implementation of software suspend on MIPS.
	Importance: Low
	
	
	Hello.  I need a help for my implementation work on MIPS software suspend.
	From 3month ago, I've been coding software suspend(swsusp) on MIPS arch.
	I'm developing with MIPS32 4KEc embedded processor for digital appliance.
	 
	Swsusp has two procedure. the one is suspending procedure and other one is resume procedure.
	Yesterday, I confirmed suspending procedure working.
	This is a porting guide of swsusp (http://tree.celinuxforum.org/CelfPubWiki/SwSuspendPortingNotes)
	I refered this article.
	 
	The problem I faced is assembly language for MIPS.
	Of course, there are many manuals for this work but, I need a help from MIPS expert.
	 
	This pseudo code should be implemented by MIPS asm.
	 
	        for (j = nr_copy_pages; j>0; j--) { 
	            src = pagedir_nosave[j].src; 
	            dst = pagedir_nosave[j].dst; 
	            for (i=0;i<1024;i++) { 
	                *dst++ = *src++; 
	            } 
	        } 
	 
	nr_copy_pages is unsigned long variable.
	and pagedir_nosave is a suspend_pagedir_t <http://lxr.linux.no/source/kernel/power/ident?v=2.6.10;i=suspend_pagedir_t>  type structure array(pointer). (you can refer following url. Line 101. : http://lxr.linux.no/source/kernel/power/swsusp.c?v=2.6.10)
	code skeleton or useful material will be welcomed. (whatever you have.)
	 
	The second problem is
	" which register should be prevented? "
	 
	I saved $v0-v1. $a0-$a3. $t0-t7. $s0-s7. $t8-t9. $gp,sp,fp,ra.

	-- 
	Hyon Lim (임현)
	Mobile. 010-8212-1240 (Intl' Call : +82-10-8212-1240)
	Fax. 032-232-0578 (Intl' Available)
	Homepage : http://www.alexlab.net
	Blog : http://www.alexlab.net/blog 


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RE: implementation of software suspend on MIPS.

[Uhler, Mike]

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I've asked our software team to follow up with you on your questions.
 
/gmu
---
Michael Uhler, VP Architecture, Software and Platform Engineering
MIPS Technologies, Inc.   Email: uhler AT mips.com
1225 Charleston Road      Voice:  (650)567-5025
Mountain View, CA 94043
  


________________________________

	From: linux-mips-bounce@linux-mips.org [mailto:linux-mips-bounce@linux-mips.org] On Behalf Of Hyon Lim
	Sent: Tuesday, October 30, 2007 12:13 PM
	To: linux-mips@linux-mips.org
	Subject:  implementation of software suspend on MIPS.
	Importance: Low
	
	
	Hello.  I need a help for my implementation work on MIPS software suspend.
	From 3month ago, I've been coding software suspend(swsusp) on MIPS arch.
	I'm developing with MIPS32 4KEc embedded processor for digital appliance.
	 
	Swsusp has two procedure. the one is suspending procedure and other one is resume procedure.
	Yesterday, I confirmed suspending procedure working.
	This is a porting guide of swsusp (http://tree.celinuxforum.org/CelfPubWiki/SwSuspendPortingNotes)
	I refered this article.
	 
	The problem I faced is assembly language for MIPS.
	Of course, there are many manuals for this work but, I need a help from MIPS expert.
	 
	This pseudo code should be implemented by MIPS asm.
	 
	        for (j = nr_copy_pages; j>0; j--) { 
	            src = pagedir_nosave[j].src; 
	            dst = pagedir_nosave[j].dst; 
	            for (i=0;i<1024;i++) { 
	                *dst++ = *src++; 
	            } 
	        } 
	 
	nr_copy_pages is unsigned long variable.
	and pagedir_nosave is a suspend_pagedir_t <http://lxr.linux.no/source/kernel/power/ident?v=2.6.10;i=suspend_pagedir_t>  type structure array(pointer). (you can refer following url. Line 101. : http://lxr.linux.no/source/kernel/power/swsusp.c?v=2.6.10)
	code skeleton or useful material will be welcomed. (whatever you have.)
	 
	The second problem is
	" which register should be prevented? "
	 
	I saved $v0-v1. $a0-$a3. $t0-t7. $s0-s7. $t8-t9. $gp,sp,fp,ra.

	-- 
	Hyon Lim (임현)
	Mobile. 010-8212-1240 (Intl' Call : +82-10-8212-1240)
	Fax. 032-232-0578 (Intl' Available)
	Homepage : http://www.alexlab.net
	Blog : http://www.alexlab.net/blog 


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Re: implementation of software suspend on MIPS.

[Hyon Lim]

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Thank you very much. I think my work is first contribution about software
suspend on mips.
I cannot find any history related to my work on this list.
I'm looking forward to receiving your answer.

On 10/31/07, Uhler, Mike <uhler@mips.com> wrote:
>
>  I've asked our software team to follow up with you on your questions.
>
>
> /gmu
> ---
> Michael Uhler, VP Architecture, Software and Platform Engineering
> MIPS Technologies, Inc.   Email: uhler AT mips.com
> 1225 Charleston Road      Voice:  (650)567-5025
> Mountain View, CA 94043
>
>
>
>
>  ------------------------------
> *From:* linux-mips-bounce@linux-mips.org [mailto:
> linux-mips-bounce@linux-mips.org] *On Behalf Of *Hyon Lim
> *Sent:* Tuesday, October 30, 2007 12:13 PM
> *To:* linux-mips@linux-mips.org
> *Subject:*  implementation of software suspend on MIPS.
> *Importance:* Low
>
>
>  Hello.  I need a help for my implementation work on MIPS software
> suspend.
> From 3month ago, I've been coding software suspend(swsusp) on MIPS arch.
> I'm developing with MIPS32 4KEc embedded processor for digital appliance.
>
> Swsusp has two procedure. the one is suspending procedure and other one is
> resume procedure.
> Yesterday, I confirmed suspending procedure working.
> This is a porting guide of swsusp (
> http://tree.celinuxforum.org/CelfPubWiki/SwSuspendPortingNotes)
> I refered this article.
>
> The problem I faced is assembly language for MIPS.
> Of course, there are many manuals for this work but, I need a help from
> MIPS expert.
>
> This pseudo code should be implemented by MIPS asm.
>
>         for (j = nr_copy_pages; j>0; j--) {
>             src = pagedir_nosave[j].src;
>             dst = pagedir_nosave[j].dst;
>             for (i=0;i<1024;i++) {
>                 *dst++ = *src++;
>             }
>         }
>
> nr_copy_pages is unsigned long variable.
> and pagedir_nosave is a suspend_pagedir_t<http://lxr.linux.no/source/kernel/power/ident?v=2.6.10;i=suspend_pagedir_t>type structure array(pointer). (you can refer following url. Line 101. :
> http://lxr.linux.no/source/kernel/power/swsusp.c?v=2.6.10)
> code skeleton or useful material will be welcomed. (whatever you have.)
>
> The second problem is
> " which register should be prevented? "
>
> I saved $v0-v1. $a0-$a3. $t0-t7. $s0-s7. $t8-t9. $gp,sp,fp,ra.
>
> --
> Hyon Lim (임현)
> Mobile. 010-8212-1240 (Intl' Call : +82-10-8212-1240)
> Fax. 032-232-0578 (Intl' Available)
> Homepage : http://www.alexlab.net
> Blog : http://www.alexlab.net/blog
>
>


-- 
Hyon Lim (임현)
Mobile. 010-8212-1240 (Intl' Call : +82-10-8212-1240)
Fax. 032-232-0578 (Intl' Available)
Homepage : http://www.alexlab.net
Blog : http://www.alexlab.net/blog

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Re: implementation of software suspend on MIPS.

[Ralf Baechle]

On Wed, Oct 31, 2007 at 04:12:36AM +0900, Hyon Lim wrote:

> Hello.  I need a help for my implementation work on MIPS software suspend.
> From 3month ago, I've been coding software suspend(swsusp) on MIPS arch.
> I'm developing with MIPS32 4KEc embedded processor for digital appliance.
> 
> Swsusp has two procedure. the one is suspending procedure and other one is
> resume procedure.
> Yesterday, I confirmed suspending procedure working.
> This is a porting guide of swsusp (
> http://tree.celinuxforum.org/CelfPubWiki/SwSuspendPortingNotes)
> I refered this article.

The article is a bit dated and lacking alot of details.

> The problem I faced is assembly language for MIPS.
> Of course, there are many manuals for this work but, I need a help from MIPS
> expert.
> 
> This pseudo code should be implemented by MIPS asm.
> 
>         for (j = nr_copy_pages; j>0; j--) {
>             src = pagedir_nosave[j].src;
>             dst = pagedir_nosave[j].dst;
>             for (i=0;i<1024;i++) {
>                 *dst++ = *src++;
>             }
>         }
> 
> nr_copy_pages is unsigned long variable.

The page is refering to some old code which no longer seems to exist in
this form.  The array pagedir_nosave has now become a chained list.  I
attach a patch for illustration purposes.  It illustrates how things work
on recent kernels; I didn't have a 2.6.10 kernel at hand.

If you have further questions on MIPS assembler then I suggest you get a
copy of Dominik Sweetman's excellent "See MIPS Run Linux" book.

> and pagedir_nosave is a
> suspend_pagedir_t<http://lxr.linux.no/source/kernel/power/ident?v=2.6.10;i=suspend_pagedir_t>type
> structure array(pointer). (you can refer following url. Line 101. :
> http://lxr.linux.no/source/kernel/power/swsusp.c?v=2.6.10)
> code skeleton or useful material will be welcomed. (whatever you have.)
> 
> The second problem is
> " which register should be prevented? "
> 
> I saved $v0-v1. $a0-$a3. $t0-t7. $s0-s7. $t8-t9. $gp,sp,fp,ra.

That sounds about right but I'd need to dive deeper into swsusp to give
you a definitive answer.

Cheers,

  Ralf

[MIPS] Skeleton swsusp implementation.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
index 3196509..38adf9e 100644
--- a/arch/mips/kernel/Makefile
+++ b/arch/mips/kernel/Makefile
@@ -75,6 +75,8 @@ obj-$(CONFIG_PCSPEAKER)		+= pcspeaker.o
 obj-$(CONFIG_KEXEC)		+= machine_kexec.o relocate_kernel.o
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 
+obj-$(CONFIG_HIBERNATION)	+= swsusp.o suspend.o
+
 CFLAGS_cpu-bugs64.o	= $(shell if $(CC) $(KBUILD_CFLAGS) -Wa,-mdaddi -c -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-DHAVE_AS_SET_DADDI"; fi)
 
 obj-$(CONFIG_HAVE_STD_PC_SERIAL_PORT)	+= 8250-platform.o
diff --git a/arch/mips/kernel/asm-offsets.c b/arch/mips/kernel/asm-offsets.c
index ca13629..f3038dc 100644
--- a/arch/mips/kernel/asm-offsets.c
+++ b/arch/mips/kernel/asm-offsets.c
@@ -13,6 +13,7 @@
 #include <linux/sched.h>
 #include <linux/mm.h>
 #include <linux/interrupt.h>
+#include <linux/suspend.h>
 
 #include <asm/ptrace.h>
 #include <asm/processor.h>
@@ -337,3 +338,13 @@ void output_irq_cpustat_t_defines(void)
 	size("#define IC_IRQ_CPUSTAT_T   ", irq_cpustat_t);
 	linefeed;
 }
+
+void output_pbe_defines(void)
+{
+	text("/* Linux struct pbe offsets. */");
+	offset("#define PBE_ADDRESS        ", struct pbe, address);
+	offset("#define PBE_ORIG_ADDRESS   ", struct pbe, orig_address);
+	offset("#define PBE_NEXT           ", struct pbe, next);
+	size("#define PBE_SIZE           ", struct pbe);
+	linefeed;
+}
diff --git a/arch/mips/kernel/suspend.S b/arch/mips/kernel/suspend.S
new file mode 100644
index 0000000..32b3ec0
--- /dev/null
+++ b/arch/mips/kernel/suspend.S
@@ -0,0 +1,20 @@
+#include <asm/asm-offsets.h>
+#include <asm/regdef.h>
+#include <asm/asm.h>
+
+LEAF(swsusp_arch_suspend)
+	END(swsusp_arch_suspend)
+
+LEAF(swsusp_arch_resume)
+	PTR_LA		t0, restore_pblist
+0:	PTR_L		t1, PBE_ADDRESS(t1)
+	PTR_L		t2, PBE_ORIG_ADDRESS(t1)
+	PTR_ADDIU	t3, t1, _PAGE_SIZE
+1:	REG_L		t4, (t1)
+	REG_S		t4, (t1)
+	PTR_ADDIU	t1, t1, SZREG
+	PTR_ADDIU	t2, t2, SZREG
+	bne		t1, t3, 1b
+	PTR_L		t1, PBE_NEXT(t1)
+	bnez		t1, 0
+	END(swsusp_arch_resume)
diff --git a/arch/mips/kernel/swsusp.c b/arch/mips/kernel/swsusp.c
new file mode 100644
index 0000000..864dd49
--- /dev/null
+++ b/arch/mips/kernel/swsusp.c
@@ -0,0 +1,30 @@
+/*
+ * Suspend support specific for power.
+ *
+ * Distribute under GPLv2
+ *
+ * Copyright (c) 2002 Pavel Machek <pavel@suse.cz>
+ * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
+ */
+
+#include <asm/page.h>
+
+/* References to section boundaries */
+extern const void __nosave_begin, __nosave_end;
+
+void save_processor_state(void)
+{
+	/* ... */
+}
+
+void restore_processor_state(void)
+{
+	/* ... */
+}
+
+int pfn_is_nosave(unsigned long pfn)
+{
+	unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT;
+	unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end)) >> PAGE_SHIFT;
+	return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
+}
diff --git a/include/asm-mips/suspend.h b/include/asm-mips/suspend.h
index 2562f8f..ee5e679 100644
--- a/include/asm-mips/suspend.h
+++ b/include/asm-mips/suspend.h
@@ -1,6 +1,9 @@
 #ifndef __ASM_SUSPEND_H
 #define __ASM_SUSPEND_H
 
-/* Somewhen...  Maybe :-)  */
+static inline int arch_prepare_suspend(void)
+{
+	return 0;
+}
 
 #endif /* __ASM_SUSPEND_H */
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 4360e08..854b7a9 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -1,7 +1,7 @@
 #ifndef _LINUX_SUSPEND_H
 #define _LINUX_SUSPEND_H
 
-#if defined(CONFIG_X86) || defined(CONFIG_FRV) || defined(CONFIG_PPC32) || defined(CONFIG_PPC64)
+#if defined(CONFIG_X86) || defined(CONFIG_FRV) || defined(CONFIG_PPC32) || defined(CONFIG_PPC64) || defined(CONFIG_MIPS)
 #include <asm/suspend.h>
 #endif
 #include <linux/swap.h>
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 8e186c6..444f835 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -99,13 +99,13 @@ config SUSPEND
 
 config HIBERNATION_UP_POSSIBLE
 	bool
-	depends on X86 || PPC64_SWSUSP || PPC32
+	depends on MIPS || X86 || PPC64_SWSUSP || PPC32
 	depends on !SMP
 	default y
 
 config HIBERNATION_SMP_POSSIBLE
 	bool
-	depends on (X86 && !X86_VOYAGER) || PPC64_SWSUSP
+	depends on MIPS || (X86 && !X86_VOYAGER) || PPC64_SWSUSP
 	depends on SMP
 	default y