[PATCH] of: Add missing node iteration stubs for disabled CONFIG_OF

[tomasz.figa@gmail.com (Tomasz Figa)]

Hi,

On Tuesday 11 of June 2013 22:51:47 Grant Likely wrote:
> On Tue, 11 Jun 2013 17:22:55 +0100, Jonathan Austin 
<jonathan.austin@arm.com> wrote:
> > Hi Rob, Thomasz,
> > 
> > (dredging up an oldish thread as I just ran in to this issue)
> > 
> > On 01/04/13 22:19, Rob Herring wrote:
> > > On 03/09/2013 02:15 PM, Tomasz Figa wrote:
> > >> This patch moves several for_each macros out of the #ifdef
> > >> CONFIG_OF
> > >> block and adds inline stubs for functions used by these macros,
> > >> compiled conditionally when CONFIG_OF is not enabled.
> > >> 
> > >> This eliminates the need to explicitly check for CONFIG_OF in
> > >> driver
> > >> code using mentioned functions and macros.
> > > 
> > > Do you have some users of this?
> > 

Oops, it looks like I have missed Rob's reply.

I had eventually managed to get rid of code that needed this patch and 
forgotten about it, but still this allowed me to track a problem with my 
mail filtering...

Best regards,
Tomasz

> > I do!
> > 
> > Or at least I might.
> > 
> > I'm not certain as perhaps the fix to what I describe below is to add
> > dependencies on CONFIG_OF - it isn't clear to me either way:
> > 
> > With both psci and arch_timers (CONFIG_ARM_PSCI,
> > CONFIG_ARM_ARCH_TIMER)
> > and without CONFIG_OF we get a build failure because we lack the
> > definition of of_find_matching_node():
> > 
> > eg:
> > arch/arm/kernel/psci.c:167:2: error: implicit declaration of function
> > ???of_find_matching_node??? [-Werror=implicit-function-declaration]
> > 
> > The same happens with arm_arch_timer.c (well, there's a patch required
> > to include linux/of.h first, after which Thomasz's patch is
> > relevant).
> That code path is completely broken if CONFIG_OF is not set. psci_init()
> is nothing but calls to CONFIG_OF infrastructure! I think that code
> needs to depend on CONFIG_OF, or at least be wrapped with
> "if (IS_ENABLED(CONFIG_OF))" if there are still usable parts when
> CONFIG_OF is disabled. Frankly I don't see that as being a real concern.
> 
> That said, Arnd has posted a patch that moves at least some of the
> function prototypes out from under the #ifdef block so that GCC can do
> syntax checking on disabled code. That overlaps a bit with this patch.
> 
> Regardless, I'm not going to apply it without a legitimate (as opposed
> to theoretical) user.
> 
> g.
> 
> > So, I guess the question is whether we should expect PSCI and
> > ARM_ARCH_TIMER to depend on CONFIG_OF, or whether we'd like them to
> > fail gracefully in the case that we *don't* have CONFIG_OF. I think
> > the current situation is broken either way...
> > 
> > Thoughts?
> > 
> > Jonny
> > 
> > > Rob
> > > 
> > >> Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
> > >> ---
> > >> 
> > >>   include/linux/of.h | 92
> > >>   +++++++++++++++++++++++++++++++++++++----------------- 1 file
> > >>   changed, 63 insertions(+), 29 deletions(-)
> > >> 
> > >> diff --git a/include/linux/of.h b/include/linux/of.h
> > >> index a0f1292..7a736b8 100644
> > >> --- a/include/linux/of.h
> > >> +++ b/include/linux/of.h
> > >> @@ -86,6 +86,31 @@ static inline struct device_node
> > >> *of_node_get(struct device_node *node)> >> 
> > >>   static inline void of_node_put(struct device_node *node) { }
> > >>   #endif /* !CONFIG_OF_DYNAMIC */
> > >> 
> > >> +#define for_each_node_by_name(dn, name) \
> > >> +     for (dn = of_find_node_by_name(NULL, name); dn; \
> > >> +          dn = of_find_node_by_name(dn, name))
> > >> +#define for_each_node_by_type(dn, type) \
> > >> +     for (dn = of_find_node_by_type(NULL, type); dn; \
> > >> +          dn = of_find_node_by_type(dn, type))
> > >> +#define for_each_compatible_node(dn, type, compatible) \
> > >> +     for (dn = of_find_compatible_node(NULL, type, compatible);
> > >> dn; \
> > >> +          dn = of_find_compatible_node(dn, type, compatible))
> > >> +#define for_each_matching_node(dn, matches) \
> > >> +     for (dn = of_find_matching_node(NULL, matches); dn; \
> > >> +          dn = of_find_matching_node(dn, matches))
> > >> +#define for_each_matching_node_and_match(dn, matches, match) \
> > >> +     for (dn = of_find_matching_node_and_match(NULL, matches,
> > >> match); \ +          dn; dn = of_find_matching_node_and_match(dn,
> > >> matches, match)) +#define for_each_child_of_node(parent, child) \
> > >> +     for (child = of_get_next_child(parent, NULL); child != NULL;
> > >> \
> > >> +          child = of_get_next_child(parent, child))
> > >> +#define for_each_available_child_of_node(parent, child) \
> > >> +     for (child = of_get_next_available_child(parent, NULL); child
> > >> != NULL; \ +          child = of_get_next_available_child(parent,
> > >> child)) +#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))
> > >> +
> > >> 
> > >>   #ifdef CONFIG_OF
> > >>   
> > >>   /* Pointer for first entry in chain of all nodes. */
> > >> 
> > >> @@ -167,19 +192,10 @@ static inline const char
> > >> *of_node_full_name(const struct device_node *np)> >> 
> > >>   extern struct device_node *of_find_node_by_name(struct
> > >>   device_node *from,> >>   
> > >>        const char *name);
> > >> 
> > >> -#define for_each_node_by_name(dn, name) \
> > >> -     for (dn = of_find_node_by_name(NULL, name); dn; \
> > >> -          dn = of_find_node_by_name(dn, name))
> > >> 
> > >>   extern struct device_node *of_find_node_by_type(struct
> > >>   device_node *from,> >>   
> > >>        const char *type);
> > >> 
> > >> -#define for_each_node_by_type(dn, type) \
> > >> -     for (dn = of_find_node_by_type(NULL, type); dn; \
> > >> -          dn = of_find_node_by_type(dn, type))
> > >> 
> > >>   extern struct device_node *of_find_compatible_node(struct
> > >>   device_node *from,> >>   
> > >>        const char *type, const char *compat);
> > >> 
> > >> -#define for_each_compatible_node(dn, type, compatible) \
> > >> -     for (dn = of_find_compatible_node(NULL, type, compatible);
> > >> dn; \
> > >> -          dn = of_find_compatible_node(dn, type, compatible))
> > >> 
> > >>   extern struct device_node *of_find_matching_node_and_match(
> > >>   
> > >>        struct device_node *from,
> > >>        const struct of_device_id *matches,
> > >> 
> > >> @@ -190,12 +206,6 @@ static inline struct device_node
> > >> *of_find_matching_node(> >> 
> > >>   {
> > >>   
> > >>        return of_find_matching_node_and_match(from, matches, NULL);
> > >>   
> > >>   }
> > >> 
> > >> -#define for_each_matching_node(dn, matches) \
> > >> -     for (dn = of_find_matching_node(NULL, matches); dn; \
> > >> -          dn = of_find_matching_node(dn, matches))
> > >> -#define for_each_matching_node_and_match(dn, matches, match) \
> > >> -     for (dn = of_find_matching_node_and_match(NULL, matches,
> > >> match); \ -          dn; dn = of_find_matching_node_and_match(dn,
> > >> matches, match))> >> 
> > >>   extern struct device_node *of_find_node_by_path(const char
> > >>   *path);
> > >>   extern struct device_node *of_find_node_by_phandle(phandle
> > >>   handle);
> > >>   extern struct device_node *of_get_parent(const struct device_node
> > >>   *node);> >> 
> > >> @@ -207,14 +217,6 @@ extern struct device_node
> > >> *of_get_next_available_child(> >> 
> > >>   extern struct device_node *of_get_child_by_name(const struct
> > >>   device_node *node,> >>   
> > >>                                        const char *name);
> > >> 
> > >> -#define for_each_child_of_node(parent, child) \
> > >> -     for (child = of_get_next_child(parent, NULL); child != NULL;
> > >> \
> > >> -          child = of_get_next_child(parent, child))
> > >> -
> > >> -#define for_each_available_child_of_node(parent, child) \
> > >> -     for (child = of_get_next_available_child(parent, NULL); child
> > >> != NULL; \ -          child = of_get_next_available_child(parent,
> > >> child)) -
> > >> 
> > >>   static inline int of_get_child_count(const struct device_node
> > >>   *np)
> > >>   {
> > >>   
> > >>        struct device_node *child;
> > >> 
> > >> @@ -228,10 +230,6 @@ static inline int of_get_child_count(const
> > >> struct device_node *np)> >> 
> > >>   extern struct device_node *of_find_node_with_property(
> > >>   
> > >>        struct device_node *from, const char *prop_name);
> > >> 
> > >> -#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))
> > >> -
> > >> 
> > >>   extern struct property *of_find_property(const struct device_node
> > >>   *np,
> > >>   
> > >>                                         const char *name,
> > >>                                         int *lenp);
> > >> 
> > >> @@ -353,13 +351,28 @@ static inline struct device_node
> > >> *of_find_node_by_name(struct device_node *from,> >> 
> > >>        return NULL;
> > >>   
> > >>   }
> > >> 
> > >> +static inline struct device_node *of_find_node_by_type(struct
> > >> device_node *from, +     const char *type)
> > >> +{
> > >> +     return NULL;
> > >> +}
> > >> +
> > >> 
> > >>   static inline bool of_have_populated_dt(void)
> > >>   {
> > >>   
> > >>        return false;
> > >>   
> > >>   }
> > >> 
> > >> -#define for_each_child_of_node(parent, child) \
> > >> -     while (0)
> > >> +static inline struct device_node *of_get_next_child(const struct
> > >> device_node *node, +                                         
> > >> struct device_node *prev) +{
> > >> +     return NULL;
> > >> +}
> > >> +
> > >> +static inline struct device_node *of_get_next_available_child(
> > >> +     const struct device_node *node, struct device_node *prev)
> > >> +{
> > >> +     return NULL;
> > >> +}
> > >> 
> > >>   static inline struct device_node *of_get_child_by_name(
> > >>   
> > >>                                        const struct device_node
> > >>                                        *node,
> > >> 
> > >> @@ -373,6 +386,12 @@ static inline int of_get_child_count(const
> > >> struct device_node *np)> >> 
> > >>        return 0;
> > >>   
> > >>   }
> > >> 
> > >> +static inline struct device_node *of_find_node_with_property(
> > >> +     struct device_node *from, const char *prop_name)
> > >> +{
> > >> +     return NULL;
> > >> +}
> > >> +
> > >> 
> > >>   static inline int of_device_is_compatible(const struct
> > >>   device_node *device,> >>   
> > >>                                          const char *name)
> > >>   
> > >>   {
> > >> 
> > >> @@ -394,6 +413,21 @@ static inline struct device_node
> > >> *of_find_compatible_node(> >> 
> > >>        return NULL;
> > >>   
> > >>   }
> > >> 
> > >> +static inline struct device_node *of_find_matching_node_and_match(
> > >> +     struct device_node *from,
> > >> +     const struct of_device_id *matches,
> > >> +     const struct of_device_id **match)
> > >> +{
> > >> +     return NULL;
> > >> +}
> > >> +
> > >> +static inline struct device_node *of_find_matching_node(
> > >> +     struct device_node *from,
> > >> +     const struct of_device_id *matches)
> > >> +{
> > >> +     return NULL;
> > >> +}
> > >> +
> > >> 
> > >>   static inline int of_property_read_u8_array(const struct
> > >>   device_node *np,> >>   
> > >>                        const char *propname, u8 *out_values, size_t
> > >>                        sz)
> > >>   
> > >>   {
> > > 
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> > 
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