NXP P50XX/e5500: SMP doesn't work anymore with the latest Git kernel

[Christian Zigotzky]

On 30 October 2018 at 02:59AM, Benjamin Herrenschmidt wrote:
> On Tue, 2018-10-30 at 02:42 +0100, Christian Zigotzky wrote:
>> OF patch for the latest Git kernel: http://www.xenosoft.de/of_v2.patch
> This just seems to revert a whole bunch of stuff, not really the right
> way to go. Why is of_get_next_cpu_node() not finding your CPUs ? There
> must be something wrong with the device-tree...
Maybe we need a new dtb for QEMU ppce500 and P50XX machines. I don't 
know. For us it is good to have this patch because we can test further. 
(other updates)
With this patch, SMP works again on virtual QEMU ppce500 and P50XX 
machines. If you have another code, then I will test it with QEMU and my 
P5020 board.

Thanks,
Christian
>
>> ----------------------------- of_v2.patch -----------------------------
>>
>> diff -rupN a/drivers/of/base.c b/drivers/of/base.c
>> --- a/drivers/of/base.c    2018-10-30 02:19:30.827089495 +0100
>> +++ b/drivers/of/base.c    2018-10-30 02:18:51.666856715 +0100
>> @@ -395,7 +395,7 @@ struct device_node *of_get_cpu_node(int
>>    {
>>        struct device_node *cpun;
>>
>> -    for_each_of_cpu_node(cpun) {
>> +    for_each_node_by_type(cpun, "cpu") {
>>            if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
>>                return cpun;
>>        }
>> @@ -750,45 +750,6 @@ struct device_node *of_get_next_availabl
>>    EXPORT_SYMBOL(of_get_next_available_child);
>>
>>    /**
>> - *    of_get_next_cpu_node - Iterate on cpu nodes
>> - *    @prev:    previous child of the /cpus node, or NULL to get first
>> - *
>> - *    Returns a cpu node pointer with refcount incremented, use
>> of_node_put()
>> - *    on it when done. Returns NULL when prev is the last child. Decrements
>> - *    the refcount of prev.
>> - */
>> -struct device_node *of_get_next_cpu_node(struct device_node *prev)
>> -{
>> -    struct device_node *next = NULL;
>> -    unsigned long flags;
>> -    struct device_node *node;
>> -
>> -    if (!prev)
>> -        node = of_find_node_by_path("/cpus");
>> -
>> -    raw_spin_lock_irqsave(&devtree_lock, flags);
>> -    if (prev)
>> -        next = prev->sibling;
>> -    else if (node) {
>> -        next = node->child;
>> -        of_node_put(node);
>> -    }
>> -    for (; next; next = next->sibling) {
>> -        if (!(of_node_name_eq(next, "cpu") ||
>> -              (next->type && !of_node_cmp(next->type, "cpu"))))
>> -            continue;
>> -        if (!__of_device_is_available(next))
>> -            continue;
>> -        if (of_node_get(next))
>> -            break;
>> -    }
>> -    of_node_put(prev);
>> -    raw_spin_unlock_irqrestore(&devtree_lock, flags);
>> -    return next;
>> -}
>> -EXPORT_SYMBOL(of_get_next_cpu_node);
>> -
>> -/**
>>     * of_get_compatible_child - Find compatible child node
>>     * @parent:    parent node
>>     * @compatible:    compatible string
>> diff -rupN a/include/linux/of.h b/include/linux/of.h
>> --- a/include/linux/of.h    2018-10-30 02:19:32.047096634 +0100
>> +++ b/include/linux/of.h    2018-10-30 02:18:51.666856715 +0100
>> @@ -347,7 +347,6 @@ extern const void *of_get_property(const
>>                    const char *name,
>>                    int *lenp);
>>    extern struct device_node *of_get_cpu_node(int cpu, unsigned int *thread);
>> -extern struct device_node *of_get_next_cpu_node(struct device_node *prev);
>>
>>    #define for_each_property_of_node(dn, pp) \
>>        for (pp = dn->properties; pp != NULL; pp = pp->next)
>> @@ -757,11 +756,6 @@ static inline struct device_node *of_get
>>        return NULL;
>>    }
>>
>> -static inline struct device_node *of_get_next_cpu_node(struct
>> device_node *prev)
>> -{
>> -    return NULL;
>> -}
>> -
>>    static inline int of_n_addr_cells(struct device_node *np)
>>    {
>>        return 0;
>> @@ -1239,10 +1233,6 @@ static inline int of_property_read_s32(c
>>        for (child = of_get_next_available_child(parent, NULL); child !=
>> NULL; \
>>             child = of_get_next_available_child(parent, child))
>>
>> -#define for_each_of_cpu_node(cpu) \
>> -    for (cpu = of_get_next_cpu_node(NULL); cpu != NULL; \
>> -         cpu = of_get_next_cpu_node(cpu))
>> -
>>    #define for_each_node_with_property(dn, prop_name) \
>>        for (dn = of_find_node_with_property(NULL, prop_name); dn; \
>>             dn = of_find_node_with_property(dn, prop_name))
>