[PATCH v2 05/15] x86/dtb: add early parsing of APIC and IO APIC
Sebastian Andrzej Siewior
bigeasy at linutronix.de
Wed Jan 19 01:56:47 EST 2011
Grant Likely wrote:
> Hi Sebastian,
Hi Grant,
>> diff --git a/arch/x86/include/asm/prom.h b/arch/x86/include/asm/prom.h
>> index 9076ae4..3bc8ed5 100644
>> --- a/arch/x86/include/asm/prom.h
>> +++ b/arch/x86/include/asm/prom.h
>> @@ -22,10 +22,17 @@
>> #include <asm/irq_controller.h>
>>
>> #ifdef CONFIG_OF
>> +extern int of_ioapic;
>> +extern u64 initial_dtb;
>> extern void add_dtb(u64 data);
>> +void x86_dtb_find_config(void);
>> +void x86_dtb_get_config(unsigned int unused);
>> void add_interrupt_host(struct irq_domain *ih);
>> #else
>> static inline void add_dtb(u64 data) { }
>> +#define x86_dtb_find_config x86_init_noop
>> +#define x86_dtb_get_config x86_init_uint_noop
>> +#define of_ioapic 0
>
> Nit: Personally, I prefer static inlines over preprocessor macros, but
> that isn't anything that will block this patch.
Right. x86 does similar for ioapic function callbacks for CONFIG_IOAPIC
case. So I keep this unless x86 folks want it different.
>> +#ifdef CONFIG_X86_IO_APIC
>> +static void __init dtb_add_ioapic(struct device_node *dn)
>> +{
>> + unsigned int ioapic_id;
>> + const __be32 *cell;
>> + int len;
>> + struct resource r;
>> + int ret;
>> +
>> + cell = of_get_property(dn, "id", &len);
>> + if (!cell) {
>> + printk(KERN_ERR "Node %s is missing id property.\n",
>> + dn->full_name);
>> + return;
>> + }
>> + ioapic_id = of_read_ulong(cell, len / 4);
>
> This looks like poor usage practise for the device tree. 'id' or any
> kind of enumeration property in a device tree node is strongly
> discouraged. As much as possible, let Linux dynamically enumerate
> devices rather than trying to explicitly specify the numbering. Since
> you can explicitly describe the relationship between device nodes in
> the tree, you should find that explicitly specifying numbers is almost
> never required.
Good point. I removed the id property and let linux statically enumerate
it. I don't see any relationship and spec. says only to keep it unique.
Sebastian
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