Attempt at addressing head*.S for modpost warnings

Attempt at addressing head*.S for modpost warnings

[Kumar Gala]

Stephen,

Paul said you were looking into this issue as well.  Wanted to post what I
did on ppc32/e500 as a start for you to look at.  I think the other ppc32
head*.S can follow the same pattern if we like this.  However, wasn't sure
how to do _ENTRY() for ppc64.

- k

diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 1f155d3..d83cbbb 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -52,9 +52,9 @@
  *   r7 - End of kernel command line string
  *
  */
-	.text
-_GLOBAL(_stext)
-_GLOBAL(_start)
+	.section	.text.head, "ax"
+_ENTRY(_stext);
+_ENTRY(_start);
 	/*
 	 * Reserve a word at a fixed location to store the address
 	 * of abatron_pteptrs
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 0c45855..823a8cb 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -34,6 +34,8 @@ SECTIONS

 	/* Text and gots */
 	.text : {
+		ALIGN_FUNCTION();
+		*(.text.head)
 		_text = .;
 		TEXT_TEXT
 		SCHED_TEXT
diff --git a/include/asm-powerpc/ppc_asm.h b/include/asm-powerpc/ppc_asm.h
index fa083d8..7ec22d2 100644
--- a/include/asm-powerpc/ppc_asm.h
+++ b/include/asm-powerpc/ppc_asm.h
@@ -183,6 +183,11 @@ GLUE(.,name):

 #else /* 32-bit */

+#define _ENTRY(n)	\
+	.stabs __stringify(n:F-1),N_FUN,0,0,n;\
+	.globl n;	\
+n:
+
 #define _GLOBAL(n)	\
 	.text;		\
 	.stabs __stringify(n:F-1),N_FUN,0,0,n;\

Re: Attempt at addressing head*.S for modpost warnings

[Stephen Rothwell]

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Hi Kumar,

[sorry for the slow reply]

On Wed, 25 Jul 2007 01:49:04 -0500 (CDT) Kumar Gala <galak@kernel.crashing.org> wrote:
>
> Paul said you were looking into this issue as well.  Wanted to post what I
> did on ppc32/e500 as a start for you to look at.  I think the other ppc32
> head*.S can follow the same pattern if we like this.  However, wasn't sure
> how to do _ENTRY() for ppc64.

What I have done so far is to put some peices of the asm code into
the .text.init.refok section (see the _INIT_STATIC macro in asm/ppc_asm.h
in the current kernel).  I was hoping to separate some of the asm into a
new file (init_64.S) that would contain this and other code in
the .init.text section.  That is currently not working (ld crashed on
me :-)).

Even if you create a .text.head, you will need to teach modpost about it.
-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au
http://www.canb.auug.org.au/~sfr/

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Re: Attempt at addressing head*.S for modpost warnings

[Kumar Gala]

On Jul 30, 2007, at 8:50 PM, Stephen Rothwell wrote:

> Hi Kumar,
>
> [sorry for the slow reply]
>
> On Wed, 25 Jul 2007 01:49:04 -0500 (CDT) Kumar Gala  
> <galak@kernel.crashing.org> wrote:
>>
>> Paul said you were looking into this issue as well.  Wanted to  
>> post what I
>> did on ppc32/e500 as a start for you to look at.  I think the  
>> other ppc32
>> head*.S can follow the same pattern if we like this.  However,  
>> wasn't sure
>> how to do _ENTRY() for ppc64.
>
> What I have done so far is to put some peices of the asm code into
> the .text.init.refok section (see the _INIT_STATIC macro in asm/ 
> ppc_asm.h
> in the current kernel).  I was hoping to separate some of the asm  
> into a
> new file (init_64.S) that would contain this and other code in
> the .init.text section.  That is currently not working (ld crashed on
> me :-)).
>
> Even if you create a .text.head, you will need to teach modpost  
> about it.

Modpost is already aware of .text.head.  Its used on x86 and a few  
other archs today.

- k