Re: [Xenomai-core] [PATCH] Fix ppc fpu support

[Heikki Lindholm <holindho@domain.hid>]

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Philippe Gerum kirjoitti:
> Heikki Lindholm wrote:
> 
>> Philippe Gerum kirjoitti:
>>
>>> Heikki Lindholm wrote:
>>>
>>>> Xenomai might preempt linux when linux has cleared a tasks MSR_FP, 
>>>> but not yet set last_task_used_math to NULL. As a result the tasks 
>>>> MSR_FP will get set, although it should be cleared. If the task 
>>>> happens to hit one of the codepaths that save FPU state if MSR_FP is 
>>>> set, the wrong FPU state might be saved to the task. The attached 
>>>> patch should fix this. I couldn't try it on most recent Xenomai 
>>>> trunk, because latency wouldn't build anymore. However, I see no 
>>>> reason it shouldn't work. All thee having trouble with X and 
>>>> Xenomai, give this a shot.
>>>>
>>>
>>> Merged in r383, thanks.
>>
>>
>>
>> On a related note, how do you think patches to Linux kernel that don't 
>> fit into I-pipe should be handled? Put into patches directory 
>> separately? There are now at least two instances for 2.6.14/ppc: the 
>> fpu bug that I already posted on this thread and the ppc64 UP building 
>> bug that effectively makes impossible to build I-pipe 2.6.14 for UP on 
>> ppc64.
>>
> 
> I'm going to put those patches on GNA, so that people can access to them 
> easily. I'm going to add a fix for x86 too, which is needed at least on 
> one of my boxen since 2.6.13 to make the PCI setup correct again.
> 
> Is this patch still the right one to fix the UP build on ppc64?
> http://patchwork.ozlabs.org/linuxppc64/patchcontent?id=3178

Yep. That makes it build. But catenate it with the following and it'll 
boot, too ;)

-- Heikki Lindholm

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diff -Nru linux-2.6.14/arch/ppc64/kernel/prom.c linux-2.6.14-dev/arch/ppc64/kernel/prom.c
--- linux-2.6.14/arch/ppc64/kernel/prom.c	2005-10-28 03:02:08.000000000 +0300
+++ linux-2.6.14-dev/arch/ppc64/kernel/prom.c	2005-11-06 14:14:07.000000000 +0200
@@ -1019,6 +1019,7 @@
 		 */
 		boot_cpuid_phys = initial_boot_params->boot_cpuid_phys;
 		boot_cpuid = 0;
+		set_hard_smp_processor_id(boot_cpuid, boot_cpuid_phys);
 	} else {
 		/* Check if it's the boot-cpu, set it's hw index in paca now */
 		if (get_flat_dt_prop(node, "linux,boot-cpu", NULL) != NULL) {