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* [PATCH] x86: fix compile warning in io_apic_{32,64}.c
@ 2008-06-05 12:05 Andreas Herrmann
  2008-06-05 12:39 ` Jack Steiner
  2008-06-10 10:21 ` Ingo Molnar
  0 siblings, 2 replies; 4+ messages in thread
From: Andreas Herrmann @ 2008-06-05 12:05 UTC (permalink / raw)
  To: Ingo Molnar, Thomas Gleixner, H. Peter Anvin; +Cc: Jack Steiner, linux-kernel

Commit 05f2d12c3563dea8c81b301f9f3cf7919af23b13
(x86: change GET_APIC_ID() from an inline function to an out-of-line function)

introduced a compile warning

arch/x86/kernel/io_apic_64.c: In function 'print_local_APIC':
arch/x86/kernel/io_apic_64.c:1152: warning: 'v' is used uninitialized in this function

in some debug code -- which is not enabled by default.
This patch reverts the code changes in print_local_APIC.

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>

--
diff --git a/arch/x86/kernel/io_apic_32.c b/arch/x86/kernel/io_apic_32.c
index a40d54f..9a3446f 100644
--- a/arch/x86/kernel/io_apic_32.c
+++ b/arch/x86/kernel/io_apic_32.c
@@ -1489,8 +1489,8 @@ void /*__init*/ print_local_APIC(void * dummy)
 
 	printk("\n" KERN_DEBUG "printing local APIC contents on CPU#%d/%d:\n",
 		smp_processor_id(), hard_smp_processor_id());
-	printk(KERN_INFO "... APIC ID:      %08x (%01x)\n", v,
-			GET_APIC_ID(read_apic_id()));
+	v = apic_read(APIC_ID);
+	printk(KERN_INFO "... APIC ID:      %08x (%01x)\n", v, GET_APIC_ID(v));
 	v = apic_read(APIC_LVR);
 	printk(KERN_INFO "... APIC VERSION: %08x\n", v);
 	ver = GET_APIC_VERSION(v);
diff --git a/arch/x86/kernel/io_apic_64.c b/arch/x86/kernel/io_apic_64.c
index ef1a8df..59ed52c 100644
--- a/arch/x86/kernel/io_apic_64.c
+++ b/arch/x86/kernel/io_apic_64.c
@@ -1077,7 +1077,8 @@ void __apicdebuginit print_local_APIC(void * dummy)
 
 	printk("\n" KERN_DEBUG "printing local APIC contents on CPU#%d/%d:\n",
 		smp_processor_id(), hard_smp_processor_id());
-	printk(KERN_INFO "... APIC ID:      %08x (%01x)\n", v, GET_APIC_ID(read_apic_id()));
+	v = apic_read(APIC_ID);
+	printk(KERN_INFO "... APIC ID:      %08x (%01x)\n", v, GET_APIC_ID(v));
 	v = apic_read(APIC_LVR);
 	printk(KERN_INFO "... APIC VERSION: %08x\n", v);
 	ver = GET_APIC_VERSION(v);





^ permalink raw reply related	[flat|nested] 4+ messages in thread
* Re: [PATCH] x86: fix compile warning in io_apic_{32,64}.c
  2008-06-05 12:05 [PATCH] x86: fix compile warning in io_apic_{32,64}.c Andreas Herrmann
@ 2008-06-05 12:39 ` Jack Steiner
  2008-06-05 14:35   ` Andreas Herrmann
  2008-06-10 10:21 ` Ingo Molnar
  1 sibling, 1 reply; 4+ messages in thread
From: Jack Steiner @ 2008-06-05 12:39 UTC (permalink / raw)
  To: Andreas Herrmann
  Cc: Ingo Molnar, Thomas Gleixner, H. Peter Anvin, linux-kernel

On Thu, Jun 05, 2008 at 02:05:57PM +0200, Andreas Herrmann wrote:
> Commit 05f2d12c3563dea8c81b301f9f3cf7919af23b13
> (x86: change GET_APIC_ID() from an inline function to an out-of-line function)
> 
> introduced a compile warning
> 
> arch/x86/kernel/io_apic_64.c: In function 'print_local_APIC':
> arch/x86/kernel/io_apic_64.c:1152: warning: 'v' is used uninitialized in this function
> 
> in some debug code -- which is not enabled by default.
> This patch reverts the code changes in print_local_APIC.
> 
> Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
> 
> --
> diff --git a/arch/x86/kernel/io_apic_32.c b/arch/x86/kernel/io_apic_32.c
> index a40d54f..9a3446f 100644
> --- a/arch/x86/kernel/io_apic_32.c
> +++ b/arch/x86/kernel/io_apic_32.c
> @@ -1489,8 +1489,8 @@ void /*__init*/ print_local_APIC(void * dummy)
>  
>  	printk("\n" KERN_DEBUG "printing local APIC contents on CPU#%d/%d:\n",
>  		smp_processor_id(), hard_smp_processor_id());
> -	printk(KERN_INFO "... APIC ID:      %08x (%01x)\n", v,
> -			GET_APIC_ID(read_apic_id()));
> +	v = apic_read(APIC_ID);
> +	printk(KERN_INFO "... APIC ID:      %08x (%01x)\n", v, GET_APIC_ID(v));
>  	v = apic_read(APIC_LVR);
>  	printk(KERN_INFO "... APIC VERSION: %08x\n", v);
>  	ver = GET_APIC_VERSION(v);
> diff --git a/arch/x86/kernel/io_apic_64.c b/arch/x86/kernel/io_apic_64.c
> index ef1a8df..59ed52c 100644
> --- a/arch/x86/kernel/io_apic_64.c
> +++ b/arch/x86/kernel/io_apic_64.c
> @@ -1077,7 +1077,8 @@ void __apicdebuginit print_local_APIC(void * dummy)
>  
>  	printk("\n" KERN_DEBUG "printing local APIC contents on CPU#%d/%d:\n",
>  		smp_processor_id(), hard_smp_processor_id());
> -	printk(KERN_INFO "... APIC ID:      %08x (%01x)\n", v, GET_APIC_ID(read_apic_id()));
> +	v = apic_read(APIC_ID);

I don't think this work on UV systems. Because of processor limitations, not
all of the APICID bits are contained in the hardware APIC_ID register. See
read_apic_id() in arch/x86/kernel/genapic_64.c.

I have not seen the compiler warning. What tree/options cause the error???


> +	printk(KERN_INFO "... APIC ID:      %08x (%01x)\n", v, GET_APIC_ID(v));
>  	v = apic_read(APIC_LVR);
>  	printk(KERN_INFO "... APIC VERSION: %08x\n", v);
>  	ver = GET_APIC_VERSION(v);
> 
> 
> 

--- jack

^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [PATCH] x86: fix compile warning in io_apic_{32,64}.c
  2008-06-05 12:39 ` Jack Steiner
@ 2008-06-05 14:35   ` Andreas Herrmann
  0 siblings, 0 replies; 4+ messages in thread
From: Andreas Herrmann @ 2008-06-05 14:35 UTC (permalink / raw)
  To: Jack Steiner; +Cc: Ingo Molnar, Thomas Gleixner, H. Peter Anvin, linux-kernel

On Thu, Jun 05, 2008 at 02:39:10PM +0200, Jack Steiner wrote:
> I have not seen the compiler warning. What tree/options cause the error???

Sure. It's currently dead code. I use it from time to time for debugging.
At least you have to do something like

diff --git a/arch/x86/kernel/io_apic_64.c b/arch/x86/kernel/io_apic_64.c
index ef1a8df..ddfdabd 100644
--- a/arch/x86/kernel/io_apic_64.c
+++ b/arch/x86/kernel/io_apic_64.c
@@ -1045,7 +1045,6 @@ void __apicdebuginit print_IO_APIC(void)
        return;
 }
 
-#if 0
 
 static __apicdebuginit void print_APIC_bitfield (int base)
 {
@@ -1181,7 +1180,6 @@ void __apicdebuginit print_PIC(void)
        printk(KERN_DEBUG "... PIC ELCR: %04x\n", v);
 }
 
-#endif  /*  0  */
 
 void __init enable_IO_APIC(void)
 {


to compile it.

> I don't think this work on UV systems. Because of processor limitations, not
> all of the APICID bits are contained in the hardware APIC_ID register. See
> read_apic_id() in arch/x86/kernel/genapic_64.c.

I am not that familar with UV. So can't really comment on that.
But then it seems that the proper adaption for print_local_APIC to avoid the warning is
---
[PATCH] x86: fix compile warning in io_apic_{32,64}.c

Commit 05f2d12c3563dea8c81b301f9f3cf7919af23b13
(x86: change GET_APIC_ID() from an inline function to an out-of-line function)
introduced a compile warning:

arch/x86/kernel/io_apic_64.c: In function 'print_local_APIC':
arch/x86/kernel/io_apic_64.c:1152: warning: 'v' is used uninitialized in this function

in some debug code -- which is disabled by default.

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
--
diff --git a/arch/x86/kernel/io_apic_32.c b/arch/x86/kernel/io_apic_32.c
index a40d54f..4fbf656 100644
--- a/arch/x86/kernel/io_apic_32.c
+++ b/arch/x86/kernel/io_apic_32.c
@@ -1489,6 +1489,7 @@ void /*__init*/ print_local_APIC(void * dummy)
 
 	printk("\n" KERN_DEBUG "printing local APIC contents on CPU#%d/%d:\n",
 		smp_processor_id(), hard_smp_processor_id());
+	v = apic_read(APIC_ID);
 	printk(KERN_INFO "... APIC ID:      %08x (%01x)\n", v,
 			GET_APIC_ID(read_apic_id()));
 	v = apic_read(APIC_LVR);
diff --git a/arch/x86/kernel/io_apic_64.c b/arch/x86/kernel/io_apic_64.c
index ef1a8df..c7c6b00 100644
--- a/arch/x86/kernel/io_apic_64.c
+++ b/arch/x86/kernel/io_apic_64.c
@@ -1077,6 +1077,7 @@ void __apicdebuginit print_local_APIC(void * dummy)
 
 	printk("\n" KERN_DEBUG "printing local APIC contents on CPU#%d/%d:\n",
 		smp_processor_id(), hard_smp_processor_id());
+	v = apic_read(APIC_ID);
 	printk(KERN_INFO "... APIC ID:      %08x (%01x)\n", v, GET_APIC_ID(read_apic_id()));
 	v = apic_read(APIC_LVR);
 	printk(KERN_INFO "... APIC VERSION: %08x\n", v);






^ permalink raw reply related	[flat|nested] 4+ messages in thread
* Re: [PATCH] x86: fix compile warning in io_apic_{32,64}.c
  2008-06-05 12:05 [PATCH] x86: fix compile warning in io_apic_{32,64}.c Andreas Herrmann
  2008-06-05 12:39 ` Jack Steiner
@ 2008-06-10 10:21 ` Ingo Molnar
  1 sibling, 0 replies; 4+ messages in thread
From: Ingo Molnar @ 2008-06-10 10:21 UTC (permalink / raw)
  To: Andreas Herrmann
  Cc: Thomas Gleixner, H. Peter Anvin, Jack Steiner, linux-kernel,
	the arch/x86 maintainers


* Andreas Herrmann <andreas.herrmann3@amd.com> wrote:

> Commit 05f2d12c3563dea8c81b301f9f3cf7919af23b13
> (x86: change GET_APIC_ID() from an inline function to an out-of-line function)
> 
> introduced a compile warning
> 
> arch/x86/kernel/io_apic_64.c: In function 'print_local_APIC':
> arch/x86/kernel/io_apic_64.c:1152: warning: 'v' is used uninitialized in this function
> 
> in some debug code -- which is not enabled by default.
> This patch reverts the code changes in print_local_APIC.

applied to tip/x86/cleanups - thanks Andreas.

	Ingo

^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2008-06-10 10:21 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2008-06-05 12:05 [PATCH] x86: fix compile warning in io_apic_{32,64}.c Andreas Herrmann
2008-06-05 12:39 ` Jack Steiner
2008-06-05 14:35   ` Andreas Herrmann
2008-06-10 10:21 ` Ingo Molnar

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