Patchwork [2/3] sparc: make driver/of/pdt no longer sparc-specific

login
register
mail settings
Submitter Andres Salomon
Date Aug. 9, 2010, 3:11 a.m.
Message ID <20100808231116.21c7d6f3@dev.queued.net>
Download mbox | patch
Permalink /patch/61245/
State Not Applicable
Delegated to: David Miller
Headers show

Comments

Andres Salomon - Aug. 9, 2010, 3:11 a.m.
Clean up pdt.c:
 - make build dependent upon config OF_PROMTREE
 - #ifdef out the sparc-specific stuff
 - create pdt-specific header
 - create a pdt_ops struct that pdt uses to call arch-specific prom routines

Signed-off-by: Andres Salomon <dilinger@queued.net>
---
 arch/sparc/Kconfig              |    1 +
 arch/sparc/include/asm/prom.h   |    5 +-
 arch/sparc/kernel/prom.h        |    6 --
 arch/sparc/kernel/prom_common.c |   57 ++++++++++++++++++++++-
 drivers/of/Kconfig              |    4 ++
 drivers/of/Makefile             |    1 +
 drivers/of/pdt.c                |   98 +++++++++++++++++++++++++-------------
 include/linux/of_pdt.h          |   42 +++++++++++++++++
 8 files changed, 171 insertions(+), 43 deletions(-)
 create mode 100644 include/linux/of_pdt.h
Grant Likely - Aug. 9, 2010, 5:12 a.m.
Hi Andres, thanks for the patch.  Comments below.

g.

On Sun, Aug 8, 2010 at 9:11 PM, Andres Salomon <dilinger@queued.net> wrote:
>
> Clean up pdt.c:
>  - make build dependent upon config OF_PROMTREE
>  - #ifdef out the sparc-specific stuff
>  - create pdt-specific header
>  - create a pdt_ops struct that pdt uses to call arch-specific prom routines
>
> Signed-off-by: Andres Salomon <dilinger@queued.net>
> ---
>  arch/sparc/Kconfig              |    1 +
>  arch/sparc/include/asm/prom.h   |    5 +-
>  arch/sparc/kernel/prom.h        |    6 --
>  arch/sparc/kernel/prom_common.c |   57 ++++++++++++++++++++++-
>  drivers/of/Kconfig              |    4 ++
>  drivers/of/Makefile             |    1 +
>  drivers/of/pdt.c                |   98 +++++++++++++++++++++++++-------------
>  include/linux/of_pdt.h          |   42 +++++++++++++++++
>  8 files changed, 171 insertions(+), 43 deletions(-)
>  create mode 100644 include/linux/of_pdt.h
>
> diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
> index 13a9f2f..ed3f009 100644
> --- a/arch/sparc/Kconfig
> +++ b/arch/sparc/Kconfig
> @@ -24,6 +24,7 @@ config SPARC
>        select HAVE_ARCH_KGDB if !SMP || SPARC64
>        select HAVE_ARCH_TRACEHOOK
>        select ARCH_WANT_OPTIONAL_GPIOLIB
> +       select OF_PROMTREE

Group this with the select OF from earlier in the config SPARC option.

>        select RTC_CLASS
>        select RTC_DRV_M48T59
>        select HAVE_PERF_EVENTS
> diff --git a/arch/sparc/include/asm/prom.h b/arch/sparc/include/asm/prom.h
> index f845828..329a976 100644
> --- a/arch/sparc/include/asm/prom.h
> +++ b/arch/sparc/include/asm/prom.h
> @@ -18,6 +18,7 @@
>  * 2 of the License, or (at your option) any later version.
>  */
>  #include <linux/types.h>
> +#include <linux/of_pdt.h>
>  #include <linux/proc_fs.h>
>  #include <linux/mutex.h>
>  #include <asm/atomic.h>
> @@ -65,8 +66,8 @@ extern struct device_node *of_console_device;
>  extern char *of_console_path;
>  extern char *of_console_options;
>
> -extern void (*prom_build_more)(struct device_node *dp, struct device_node ***nextp);
> -extern char *build_full_name(struct device_node *dp);
> +extern void irq_trans_init(struct device_node *dp);
> +extern char *build_path_component(struct device_node *dp);
>
>  #endif /* __KERNEL__ */
>  #endif /* _SPARC_PROM_H */
> diff --git a/arch/sparc/kernel/prom.h b/arch/sparc/kernel/prom.h
> index eeb04a7..cf5fe1c 100644
> --- a/arch/sparc/kernel/prom.h
> +++ b/arch/sparc/kernel/prom.h
> @@ -4,12 +4,6 @@
>  #include <linux/spinlock.h>
>  #include <asm/prom.h>
>
> -extern void * prom_early_alloc(unsigned long size);
> -extern void irq_trans_init(struct device_node *dp);
> -
> -extern unsigned int prom_unique_id;
> -
> -extern char *build_path_component(struct device_node *dp);
>  extern void of_console_init(void);
>
>  extern unsigned int prom_early_allocated;
> diff --git a/arch/sparc/kernel/prom_common.c b/arch/sparc/kernel/prom_common.c
> index 7b454f6..4c5f67f 100644
> --- a/arch/sparc/kernel/prom_common.c
> +++ b/arch/sparc/kernel/prom_common.c
> @@ -20,6 +20,7 @@
>  #include <linux/mutex.h>
>  #include <linux/slab.h>
>  #include <linux/of.h>
> +#include <linux/of_pdt.h>
>  #include <asm/prom.h>
>  #include <asm/oplib.h>
>  #include <asm/leon.h>
> @@ -117,6 +118,60 @@ int of_find_in_proplist(const char *list, const char *match, int len)
>  }
>  EXPORT_SYMBOL(of_find_in_proplist);
>
> +/*
> + * SPARC32 and SPARC64's prom_firstprop/prom_nextprop do things differently
> + * here, despite sharing the same interface.  SPARC32 doesn't fill in 'buf',
> + * returning NULL on an error.  SPARC64 fills in 'buf', but sets it to an
> + * empty string upon error.
> + */
> +static int __init handle_prop_quirks(char *buf, const char *name)
> +{
> +       if (!name || strlen(name) == 0)
> +               return -1;
> +
> +#ifdef CONFIG_SPARC32
> +       strcpy(buf, name);
> +#endif
> +       return 0;
> +}
> +
> +static int __init prom_common_firstprop(phandle node, char *buf)
> +{
> +       const char *name;
> +
> +       buf[0] = '\0';
> +       name = prom_firstprop(node, buf);
> +       return handle_prop_quirks(buf, name);
> +}
> +
> +static int __init prom_common_nextprop(phandle node, const char *prev,
> +               char *buf)
> +{
> +       const char *name;
> +
> +       buf[0] = '\0';
> +       name = prom_nextprop(node, prev, buf);
> +       return handle_prop_quirks(buf, name);
> +}

Rather than having both prom_common_{firstprop,nextprop}(), there only
needs to be one hook; prom_common_nextprop().  Make it use the
firstprop behaviour when it is passed a NULL in the prev pointer.
This will simplify the users of this code further down.

> +
>  unsigned int prom_early_allocated __initdata;
>
> -#include "../../../drivers/of/pdt.c"
> +static struct of_pdt_ops prom_sparc_ops __initdata = {
> +       .firstprop = prom_common_firstprop,
> +       .nextprop = prom_common_nextprop,
> +       .getproplen = (int (*)(phandle, const char *))prom_getproplen,
> +       .getproperty = (int (*)(phandle, const char *, char *, int))prom_getproperty,
> +       .getchild = (phandle (*)(phandle))prom_getchild,
> +       .getsibling = (phandle (*)(phandle))prom_getsibling,

If you have to explicitly cast these function pointers, then you're
doing it wrong.  :-)  Listen to and fix the compiler complaint here.

> +};
> +
> +void __init prom_build_devicetree(void)
> +{
> +       of_pdt_set_ops(&prom_sparc_ops);
> +       of_pdt_build_devicetree(prom_root_node);

Maybe I'm being nitpicky here, but I would pass the ops structure into
of_pdt_build_devicetree() directly.  I don't like the implied state of
setting the ops pointer separate from parsing the tree.

> +
> +       of_console_init();
> +
> +       printk(KERN_INFO "PROM: Built device tree with %u bytes of memory.\n",
> +              prom_early_allocated);

pr_info()

> +}
> diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
> index 1678dbc..c8a4b7c 100644
> --- a/drivers/of/Kconfig
> +++ b/drivers/of/Kconfig
> @@ -5,6 +5,10 @@ config OF_FLATTREE
>        bool
>        depends on OF
>
> +config OF_PROMTREE
> +       bool
> +       depends on OF
> +

I can tell from the context here you're working from an older tree.
Please rebase onto Linus' current top-of-tree.  :-)  A bunch of OF
related patches have been merged for 2.6.36 that will conflict with
this patch.

>  config OF_DYNAMIC
>        def_bool y
>        depends on OF && PPC_OF
> diff --git a/drivers/of/Makefile b/drivers/of/Makefile
> index f232cc9..54e8517 100644
> --- a/drivers/of/Makefile
> +++ b/drivers/of/Makefile
> @@ -1,5 +1,6 @@
>  obj-y = base.o
>  obj-$(CONFIG_OF_FLATTREE) += fdt.o
> +obj-$(CONFIG_OF_PROMTREE) += pdt.o
>  obj-$(CONFIG_OF_DEVICE) += device.o platform.o
>  obj-$(CONFIG_OF_GPIO)   += gpio.o
>  obj-$(CONFIG_OF_I2C)   += of_i2c.o
> diff --git a/drivers/of/pdt.c b/drivers/of/pdt.c
> index 61d9477..22f46fb 100644
> --- a/drivers/of/pdt.c
> +++ b/drivers/of/pdt.c
> @@ -1,5 +1,4 @@
> -/* prom_common.c: OF device tree support common code.
> - *
> +/*

You should still retain a one-line description of what this file is for.

>  * Paul Mackerras      August 1996.
>  * Copyright (C) 1996-2005 Paul Mackerras.
>  *
> @@ -7,6 +6,7 @@
>  *    {engebret|bergner}@us.ibm.com
>  *
>  *  Adapted for sparc by David S. Miller davem@davemloft.net
> + *  Adapted for multiple architectures by Andres Salomon <dilinger@queued.net>
>  *
>  *      This program is free software; you can redistribute it and/or
>  *      modify it under the terms of the GNU General Public License
> @@ -20,13 +20,44 @@
>  #include <linux/mutex.h>
>  #include <linux/slab.h>
>  #include <linux/of.h>
> +#include <linux/of_pdt.h>
>  #include <asm/prom.h>
> -#include <asm/oplib.h>
> -#include <asm/leon.h>
>
> -void (*prom_build_more)(struct device_node *dp, struct device_node ***nextp);
> +void __initdata (*prom_build_more)(struct device_node *dp,
> +               struct device_node ***nextp);
> +
> +static struct of_pdt_ops prom_ops __initdata;

Why a full copy of the structure instead of a pointer?

> +
> +#if defined(CONFIG_SPARC)
> +static unsigned int prom_unique_id __initdata;
> +
> +#define inc_unique_id(p) do { \
> +       (p)->unique_id = prom_unique_id++; \
> +} while (0)

Use a static inline.  C code is preferred over preprocessor code.
Also preserver the namespace and use the of_pdt_ prefix (that goes for
all the new functions here in this file).

> +
> +static inline const char *fetch_node_name(struct device_node *dp)
> +{
> +       return dp->path_component_name;
> +}
> +
> +#else
> +
> +static inline void inc_unique_id(void *p)
> +{
> +       /* unused on non-SPARC architectures */
> +}
> +
> +static inline const char *fetch_node_name(struct device_node *dp)
> +{
> +       return dp->name;
> +}

It would be nice to rationalize the differences between how sparc and
powerpc use the ->name/->path_component_name fields; but I haven't
investigated what the differences are.

> +
> +static inline void irq_trans_init(struct device_node *dp)
> +{
> +       /* unused on non-SPARC architectures */
> +}

For empty statics like this; I'm fine with this more concise form:

+static inline void inc_unique_id(void *p) { }
+static inline void irq_trans_init(struct device_node *dp) { }

(again, add the of_pdt_ prefix)

>
> -unsigned int prom_unique_id;
> +#endif /* !CONFIG_SPARC */
>
>  static struct property * __init build_one_prop(phandle node, char *prev,
>                                               char *special_name,
> @@ -35,7 +66,6 @@ static struct property * __init build_one_prop(phandle node, char *prev,
>  {
>        static struct property *tmp = NULL;
>        struct property *p;
> -       const char *name;
>
>        if (tmp) {
>                p = tmp;
> @@ -43,7 +73,7 @@ static struct property * __init build_one_prop(phandle node, char *prev,
>                tmp = NULL;
>        } else {
>                p = prom_early_alloc(sizeof(struct property) + 32);
> -               p->unique_id = prom_unique_id++;
> +               inc_unique_id(p);
>        }
>
>        p->name = (char *) (p + 1);
> @@ -53,27 +83,24 @@ static struct property * __init build_one_prop(phandle node, char *prev,
>                p->value = prom_early_alloc(special_len);
>                memcpy(p->value, special_val, special_len);
>        } else {
> -               if (prev == NULL) {
> -                       name = prom_firstprop(node, p->name);
> -               } else {
> -                       name = prom_nextprop(node, prev, p->name);
> -               }
> +               int err;
>
> -               if (!name || strlen(name) == 0) {
> +               if (prev == NULL)
> +                       err = prom_ops.firstprop(node, p->name);
> +               else
> +                       err = prom_ops.nextprop(node, prev, p->name);

As mentioned earlier, this is better with a single .nextprop() hook
that behaves differently when a NULL prev pointer is passed.

> +               if (err) {
>                        tmp = p;
>                        return NULL;
>                }
> -#ifdef CONFIG_SPARC32
> -               strcpy(p->name, name);
> -#endif
> -               p->length = prom_getproplen(node, p->name);
> +               p->length = prom_ops.getproplen(node, p->name);
>                if (p->length <= 0) {
>                        p->length = 0;
>                } else {
>                        int len;
>
>                        p->value = prom_early_alloc(p->length + 1);
> -                       len = prom_getproperty(node, p->name, p->value,
> +                       len = prom_ops.getproperty(node, p->name, p->value,
>                                               p->length);
>                        if (len <= 0)
>                                p->length = 0;
> @@ -106,10 +133,10 @@ static char * __init get_one_property(phandle node, const char *name)
>        char *buf = "<NULL>";
>        int len;
>
> -       len = prom_getproplen(node, name);
> +       len = prom_ops.getproplen(node, name);
>        if (len > 0) {
>                buf = prom_early_alloc(len);
> -               len = prom_getproperty(node, name, buf, len);
> +               len = prom_ops.getproperty(node, name, buf, len);
>        }
>
>        return buf;
> @@ -124,7 +151,7 @@ static struct device_node * __init prom_create_node(phandle node,
>                return NULL;
>
>        dp = prom_early_alloc(sizeof(*dp));
> -       dp->unique_id = prom_unique_id++;
> +       inc_unique_id(dp);
>        dp->parent = parent;
>
>        kref_init(&dp->kref);
> @@ -140,13 +167,13 @@ static struct device_node * __init prom_create_node(phandle node,
>        return dp;
>  }
>
> -char * __init build_full_name(struct device_node *dp)
> +static char * __init build_full_name(struct device_node *dp)
>  {
>        int len, ourlen, plen;
>        char *n;
>
>        plen = strlen(dp->parent->full_name);
> -       ourlen = strlen(dp->path_component_name);
> +       ourlen = strlen(fetch_node_name(dp));
>        len = ourlen + plen + 2;
>
>        n = prom_early_alloc(len);
> @@ -155,7 +182,7 @@ char * __init build_full_name(struct device_node *dp)
>                strcpy(n + plen, "/");
>                plen++;
>        }
> -       strcpy(n + plen, dp->path_component_name);
> +       strcpy(n + plen, fetch_node_name(dp));
>
>        return n;
>  }
> @@ -182,36 +209,39 @@ static struct device_node * __init prom_build_tree(struct device_node *parent,
>                *(*nextp) = dp;
>                *nextp = &dp->allnext;
>
> +#if defined(CONFIG_SPARC)
>                dp->path_component_name = build_path_component(dp);
> +#endif
>                dp->full_name = build_full_name(dp);
>
> -               dp->child = prom_build_tree(dp, prom_getchild(node), nextp);
> +               dp->child = prom_build_tree(dp, prom_ops.getchild(node), nextp);
>
>                if (prom_build_more)
>                        prom_build_more(dp, nextp);
>
> -               node = prom_getsibling(node);
> +               node = prom_ops.getsibling(node);
>        }
>
>        return ret;
>  }
>
> -void __init prom_build_devicetree(void)
> +void __init of_pdt_build_devicetree(int root_node)
>  {
>        struct device_node **nextp;
>
> -       allnodes = prom_create_node(prom_root_node, NULL);
> +       allnodes = prom_create_node(root_node, NULL);
>        allnodes->path_component_name = "";
>        allnodes->full_name = "/";
>
>        nextp = &allnodes->allnext;
>        allnodes->child = prom_build_tree(allnodes,
> -                       prom_getchild(allnodes->phandle),
> +                       prom_ops.getchild(allnodes->phandle),
>                        &nextp);
> +}
>
> -       of_console_init();
> +void __init of_pdt_set_ops(struct of_pdt_ops *ops)
> +{
> +       BUG_ON(!ops);
>
> -       printk("PROM: Built device tree with %u bytes of memory.\n",
> -              prom_early_allocated);
> +       prom_ops = *ops;

As mentioned above, why is the structure copied instead of just
storing the pointer.

>  }
> -
> diff --git a/include/linux/of_pdt.h b/include/linux/of_pdt.h
> new file mode 100644
> index 0000000..1324ba5
> --- /dev/null
> +++ b/include/linux/of_pdt.h
> @@ -0,0 +1,42 @@
> +/*
> + * Definitions for building a device tree by calling into the
> + * Open Firmware PROM.
> + *
> + * Copyright (C) 2010  Andres Salomon <dilinger@queued.net>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version
> + * 2 of the License, or (at your option) any later version.
> + */
> +
> +#ifndef _LINUX_OF_PDT_H
> +#define _LINUX_OF_PDT_H
> +
> +extern void *prom_early_alloc(unsigned long size);
> +
> +/* overridable operations for calling into the PROM */
> +struct of_pdt_ops {
> +       /* buffers passed should be 32 bytes; return 0 on success */
> +       int (*firstprop)(phandle node, char *buf);
> +       int (*nextprop)(phandle node, const char *prev, char *buf);
> +
> +       /* for both functions, return proplen on success; -1 on error */
> +       int (*getproplen)(phandle node, const char *prop);
> +       int (*getproperty)(phandle node, const char *prop, char *buf,
> +                       int bufsize);
> +
> +       /* phandles are 0 if no child or sibling exists */
> +       phandle (*getchild)(phandle parent);
> +       phandle (*getsibling)(phandle node);
> +};
> +
> +extern void of_pdt_set_ops(struct of_pdt_ops *ops);
> +
> +/* for building the device tree */
> +extern void of_pdt_build_devicetree(int root_node);
> +
> +extern void (*prom_build_more)(struct device_node *dp,
> +               struct device_node ***nextp);
> +
> +#endif /* _LINUX_OF_PDT_H */
> --
> 1.5.6.5
>
>
Andres Salomon - Aug. 9, 2010, 5:32 a.m.
On Sun, 8 Aug 2010 23:12:21 -0600
Grant Likely <grant.likely@secretlab.ca> wrote:

> Hi Andres, thanks for the patch.  Comments below.
> 
> g.
> 
> On Sun, Aug 8, 2010 at 9:11 PM, Andres Salomon <dilinger@queued.net>
> wrote:
[...]
> > +
> >  unsigned int prom_early_allocated __initdata;
> >
> > -#include "../../../drivers/of/pdt.c"
> > +static struct of_pdt_ops prom_sparc_ops __initdata = {
> > +       .firstprop = prom_common_firstprop,
> > +       .nextprop = prom_common_nextprop,
> > +       .getproplen = (int (*)(phandle, const char
> > *))prom_getproplen,
> > +       .getproperty = (int (*)(phandle, const char *, char *,
> > int))prom_getproperty,
> > +       .getchild = (phandle (*)(phandle))prom_getchild,
> > +       .getsibling = (phandle (*)(phandle))prom_getsibling,
> 
> If you have to explicitly cast these function pointers, then you're
> doing it wrong.  :-)  Listen to and fix the compiler complaint here.
> 

Hm, can you please expand on that?  The reason it's necessary to cast is
because sparc's prom_* functions are using ints instead of phandles.  I
don't understand why casting is the wrong thing here.

I could write some 1-line wrapper functions that simply call prom_*
rather than casting, I suppose.

[...]
> > +}
> > diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
> > index 1678dbc..c8a4b7c 100644
> > --- a/drivers/of/Kconfig
> > +++ b/drivers/of/Kconfig
> > @@ -5,6 +5,10 @@ config OF_FLATTREE
> >        bool
> >        depends on OF
> >
> > +config OF_PROMTREE
> > +       bool
> > +       depends on OF
> > +
> 
> I can tell from the context here you're working from an older tree.
> Please rebase onto Linus' current top-of-tree.  :-)  A bunch of OF
> related patches have been merged for 2.6.36 that will conflict with
> this patch.
> 

Sorry, will do.  Was just looking for more feedback (while testing)
before sending final versions of this stuff.


[...]
> 
> > +
> > +#if defined(CONFIG_SPARC)
> > +static unsigned int prom_unique_id __initdata;
> > +
> > +#define inc_unique_id(p) do { \
> > +       (p)->unique_id = prom_unique_id++; \
> > +} while (0)
> 
> Use a static inline.  C code is preferred over preprocessor code.
> Also preserver the namespace and use the of_pdt_ prefix (that goes for
> all the new functions here in this file).

This is processing multiple types, that's the reason for the macro.

'p' can be either a property struct, or device_node struct.


[...]
> > -       of_console_init();
> > +void __init of_pdt_set_ops(struct of_pdt_ops *ops)
> > +{
> > +       BUG_ON(!ops);
> >
> > -       printk("PROM: Built device tree with %u bytes of memory.\n",
> > -              prom_early_allocated);
> > +       prom_ops = *ops;
> 
> As mentioned above, why is the structure copied instead of just
> storing the pointer.
> 

Er, right, because originally the struct was handled differently.  No
reason for it to be copied anymore.

Thanks for the feedback!
--
To unsubscribe from this list: send the line "unsubscribe sparclinux" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
David Miller - Aug. 9, 2010, 5:34 a.m.
From: Andres Salomon <dilinger@queued.net>
Date: Mon, 9 Aug 2010 01:32:45 -0400

> On Sun, 8 Aug 2010 23:12:21 -0600
> Grant Likely <grant.likely@secretlab.ca> wrote:
> 
>> If you have to explicitly cast these function pointers, then you're
>> doing it wrong.  :-)  Listen to and fix the compiler complaint here.
>> 
> 
> Hm, can you please expand on that?  The reason it's necessary to cast is
> because sparc's prom_* functions are using ints instead of phandles.  I
> don't understand why casting is the wrong thing here.
> 
> I could write some 1-line wrapper functions that simply call prom_*
> rather than casting, I suppose.

There's no reason the Sparc interfaces can't take phandles since they
are just ints, and that would make the call signatures of these
functions compatible with the types used by the other architectures.
--
To unsubscribe from this list: send the line "unsubscribe sparclinux" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Grant Likely - Aug. 9, 2010, 5:41 a.m.
On Sun, Aug 8, 2010 at 11:32 PM, Andres Salomon <dilinger@queued.net> wrote:
> On Sun, 8 Aug 2010 23:12:21 -0600
> Grant Likely <grant.likely@secretlab.ca> wrote:
>
>> Hi Andres, thanks for the patch.  Comments below.
>>
>> g.
>>
>> On Sun, Aug 8, 2010 at 9:11 PM, Andres Salomon <dilinger@queued.net>
>> wrote:
> [...]
>> > +
>> >  unsigned int prom_early_allocated __initdata;
>> >
>> > -#include "../../../drivers/of/pdt.c"
>> > +static struct of_pdt_ops prom_sparc_ops __initdata = {
>> > +       .firstprop = prom_common_firstprop,
>> > +       .nextprop = prom_common_nextprop,
>> > +       .getproplen = (int (*)(phandle, const char
>> > *))prom_getproplen,
>> > +       .getproperty = (int (*)(phandle, const char *, char *,
>> > int))prom_getproperty,
>> > +       .getchild = (phandle (*)(phandle))prom_getchild,
>> > +       .getsibling = (phandle (*)(phandle))prom_getsibling,
>>
>> If you have to explicitly cast these function pointers, then you're
>> doing it wrong.  :-)  Listen to and fix the compiler complaint here.
>>
>
> Hm, can you please expand on that?  The reason it's necessary to cast is
> because sparc's prom_* functions are using ints instead of phandles.  I
> don't understand why casting is the wrong thing here.

because casting will mean the compiler can no longer catch errors when
someone accidentally assigns an incompatible function.

>> I can tell from the context here you're working from an older tree.
>> Please rebase onto Linus' current top-of-tree.  :-)  A bunch of OF
>> related patches have been merged for 2.6.36 that will conflict with
>> this patch.
>>
>
> Sorry, will do.  Was just looking for more feedback (while testing)
> before sending final versions of this stuff.

:-)

>>
>> > +
>> > +#if defined(CONFIG_SPARC)
>> > +static unsigned int prom_unique_id __initdata;
>> > +
>> > +#define inc_unique_id(p) do { \
>> > +       (p)->unique_id = prom_unique_id++; \
>> > +} while (0)
>>
>> Use a static inline.  C code is preferred over preprocessor code.
>> Also preserver the namespace and use the of_pdt_ prefix (that goes for
>> all the new functions here in this file).
>
> This is processing multiple types, that's the reason for the macro.
>
> 'p' can be either a property struct, or device_node struct.

Ah, right.  I missed that.  A little ugly.  Personally I'd rather be
explicit and have a separate static inline for each usage.

> [...]
>> > -       of_console_init();
>> > +void __init of_pdt_set_ops(struct of_pdt_ops *ops)
>> > +{
>> > +       BUG_ON(!ops);
>> >
>> > -       printk("PROM: Built device tree with %u bytes of memory.\n",
>> > -              prom_early_allocated);
>> > +       prom_ops = *ops;
>>
>> As mentioned above, why is the structure copied instead of just
>> storing the pointer.
>>
>
> Er, right, because originally the struct was handled differently.  No
> reason for it to be copied anymore.
>
> Thanks for the feedback!

np

g.
Andres Salomon - Aug. 16, 2010, 4:22 a.m.
On Sun, 08 Aug 2010 22:34:44 -0700 (PDT)
David Miller <davem@davemloft.net> wrote:

> From: Andres Salomon <dilinger@queued.net>
> Date: Mon, 9 Aug 2010 01:32:45 -0400
> 
> > On Sun, 8 Aug 2010 23:12:21 -0600
> > Grant Likely <grant.likely@secretlab.ca> wrote:
> > 
> >> If you have to explicitly cast these function pointers, then you're
> >> doing it wrong.  :-)  Listen to and fix the compiler complaint
> >> here.
> >> 
> > 
> > Hm, can you please expand on that?  The reason it's necessary to
> > cast is because sparc's prom_* functions are using ints instead of
> > phandles.  I don't understand why casting is the wrong thing here.
> > 
> > I could write some 1-line wrapper functions that simply call prom_*
> > rather than casting, I suppose.
> 
> There's no reason the Sparc interfaces can't take phandles since they
> are just ints, and that would make the call signatures of these
> functions compatible with the types used by the other architectures.

You're saying to convert the sparc code to use phandles?  Doing so has
caused phandles to show up in asm/openprom.h (linux_dev_v2_funcs's
v2_inst2pkg returns a phandle, and linux_nodeops use phandles).  This
is fine, except asm/openprom.h is an exported kernel header, and
linux/of.h is not.

I'm tempted to break the phandle/device_node/property stuff out into a
separate header (that gets exported), and include that from linux/of.h
and asm/openprom.h.
--
To unsubscribe from this list: send the line "unsubscribe sparclinux" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
David Miller - Aug. 16, 2010, 6:17 a.m.
From: Andres Salomon <dilinger@queued.net>
Date: Mon, 16 Aug 2010 00:22:44 -0400

> I'm tempted to break the phandle/device_node/property stuff out into a
> separate header (that gets exported), and include that from linux/of.h
> and asm/openprom.h.

We could put just phandle into linux/types.h
--
To unsubscribe from this list: send the line "unsubscribe sparclinux" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 13a9f2f..ed3f009 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -24,6 +24,7 @@  config SPARC
 	select HAVE_ARCH_KGDB if !SMP || SPARC64
 	select HAVE_ARCH_TRACEHOOK
 	select ARCH_WANT_OPTIONAL_GPIOLIB
+	select OF_PROMTREE
 	select RTC_CLASS
 	select RTC_DRV_M48T59
 	select HAVE_PERF_EVENTS
diff --git a/arch/sparc/include/asm/prom.h b/arch/sparc/include/asm/prom.h
index f845828..329a976 100644
--- a/arch/sparc/include/asm/prom.h
+++ b/arch/sparc/include/asm/prom.h
@@ -18,6 +18,7 @@ 
  * 2 of the License, or (at your option) any later version.
  */
 #include <linux/types.h>
+#include <linux/of_pdt.h>
 #include <linux/proc_fs.h>
 #include <linux/mutex.h>
 #include <asm/atomic.h>
@@ -65,8 +66,8 @@  extern struct device_node *of_console_device;
 extern char *of_console_path;
 extern char *of_console_options;
 
-extern void (*prom_build_more)(struct device_node *dp, struct device_node ***nextp);
-extern char *build_full_name(struct device_node *dp);
+extern void irq_trans_init(struct device_node *dp);
+extern char *build_path_component(struct device_node *dp);
 
 #endif /* __KERNEL__ */
 #endif /* _SPARC_PROM_H */
diff --git a/arch/sparc/kernel/prom.h b/arch/sparc/kernel/prom.h
index eeb04a7..cf5fe1c 100644
--- a/arch/sparc/kernel/prom.h
+++ b/arch/sparc/kernel/prom.h
@@ -4,12 +4,6 @@ 
 #include <linux/spinlock.h>
 #include <asm/prom.h>
 
-extern void * prom_early_alloc(unsigned long size);
-extern void irq_trans_init(struct device_node *dp);
-
-extern unsigned int prom_unique_id;
-
-extern char *build_path_component(struct device_node *dp);
 extern void of_console_init(void);
 
 extern unsigned int prom_early_allocated;
diff --git a/arch/sparc/kernel/prom_common.c b/arch/sparc/kernel/prom_common.c
index 7b454f6..4c5f67f 100644
--- a/arch/sparc/kernel/prom_common.c
+++ b/arch/sparc/kernel/prom_common.c
@@ -20,6 +20,7 @@ 
 #include <linux/mutex.h>
 #include <linux/slab.h>
 #include <linux/of.h>
+#include <linux/of_pdt.h>
 #include <asm/prom.h>
 #include <asm/oplib.h>
 #include <asm/leon.h>
@@ -117,6 +118,60 @@  int of_find_in_proplist(const char *list, const char *match, int len)
 }
 EXPORT_SYMBOL(of_find_in_proplist);
 
+/*
+ * SPARC32 and SPARC64's prom_firstprop/prom_nextprop do things differently
+ * here, despite sharing the same interface.  SPARC32 doesn't fill in 'buf',
+ * returning NULL on an error.  SPARC64 fills in 'buf', but sets it to an
+ * empty string upon error.
+ */
+static int __init handle_prop_quirks(char *buf, const char *name)
+{
+	if (!name || strlen(name) == 0)
+		return -1;
+
+#ifdef CONFIG_SPARC32
+	strcpy(buf, name);
+#endif
+	return 0;
+}
+
+static int __init prom_common_firstprop(phandle node, char *buf)
+{
+	const char *name;
+
+	buf[0] = '\0';
+	name = prom_firstprop(node, buf);
+	return handle_prop_quirks(buf, name);
+}
+
+static int __init prom_common_nextprop(phandle node, const char *prev,
+		char *buf)
+{
+	const char *name;
+
+	buf[0] = '\0';
+	name = prom_nextprop(node, prev, buf);
+	return handle_prop_quirks(buf, name);
+}
+
 unsigned int prom_early_allocated __initdata;
 
-#include "../../../drivers/of/pdt.c"
+static struct of_pdt_ops prom_sparc_ops __initdata = {
+	.firstprop = prom_common_firstprop,
+	.nextprop = prom_common_nextprop,
+	.getproplen = (int (*)(phandle, const char *))prom_getproplen,
+	.getproperty = (int (*)(phandle, const char *, char *, int))prom_getproperty,
+	.getchild = (phandle (*)(phandle))prom_getchild,
+	.getsibling = (phandle (*)(phandle))prom_getsibling,
+};
+
+void __init prom_build_devicetree(void)
+{
+	of_pdt_set_ops(&prom_sparc_ops);
+	of_pdt_build_devicetree(prom_root_node);
+
+	of_console_init();
+
+	printk(KERN_INFO "PROM: Built device tree with %u bytes of memory.\n",
+	       prom_early_allocated);
+}
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index 1678dbc..c8a4b7c 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -5,6 +5,10 @@  config OF_FLATTREE
 	bool
 	depends on OF
 
+config OF_PROMTREE
+	bool
+	depends on OF
+
 config OF_DYNAMIC
 	def_bool y
 	depends on OF && PPC_OF
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index f232cc9..54e8517 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -1,5 +1,6 @@ 
 obj-y = base.o
 obj-$(CONFIG_OF_FLATTREE) += fdt.o
+obj-$(CONFIG_OF_PROMTREE) += pdt.o
 obj-$(CONFIG_OF_DEVICE) += device.o platform.o
 obj-$(CONFIG_OF_GPIO)   += gpio.o
 obj-$(CONFIG_OF_I2C)	+= of_i2c.o
diff --git a/drivers/of/pdt.c b/drivers/of/pdt.c
index 61d9477..22f46fb 100644
--- a/drivers/of/pdt.c
+++ b/drivers/of/pdt.c
@@ -1,5 +1,4 @@ 
-/* prom_common.c: OF device tree support common code.
- *
+/*
  * Paul Mackerras	August 1996.
  * Copyright (C) 1996-2005 Paul Mackerras.
  *
@@ -7,6 +6,7 @@ 
  *    {engebret|bergner}@us.ibm.com
  *
  *  Adapted for sparc by David S. Miller davem@davemloft.net
+ *  Adapted for multiple architectures by Andres Salomon <dilinger@queued.net>
  *
  *      This program is free software; you can redistribute it and/or
  *      modify it under the terms of the GNU General Public License
@@ -20,13 +20,44 @@ 
 #include <linux/mutex.h>
 #include <linux/slab.h>
 #include <linux/of.h>
+#include <linux/of_pdt.h>
 #include <asm/prom.h>
-#include <asm/oplib.h>
-#include <asm/leon.h>
 
-void (*prom_build_more)(struct device_node *dp, struct device_node ***nextp);
+void __initdata (*prom_build_more)(struct device_node *dp,
+		struct device_node ***nextp);
+
+static struct of_pdt_ops prom_ops __initdata;
+
+#if defined(CONFIG_SPARC)
+static unsigned int prom_unique_id __initdata;
+
+#define inc_unique_id(p) do { \
+	(p)->unique_id = prom_unique_id++; \
+} while (0)
+
+static inline const char *fetch_node_name(struct device_node *dp)
+{
+	return dp->path_component_name;
+}
+
+#else
+
+static inline void inc_unique_id(void *p)
+{
+	/* unused on non-SPARC architectures */
+}
+
+static inline const char *fetch_node_name(struct device_node *dp)
+{
+	return dp->name;
+}
+
+static inline void irq_trans_init(struct device_node *dp)
+{
+	/* unused on non-SPARC architectures */
+}
 
-unsigned int prom_unique_id;
+#endif /* !CONFIG_SPARC */
 
 static struct property * __init build_one_prop(phandle node, char *prev,
 					       char *special_name,
@@ -35,7 +66,6 @@  static struct property * __init build_one_prop(phandle node, char *prev,
 {
 	static struct property *tmp = NULL;
 	struct property *p;
-	const char *name;
 
 	if (tmp) {
 		p = tmp;
@@ -43,7 +73,7 @@  static struct property * __init build_one_prop(phandle node, char *prev,
 		tmp = NULL;
 	} else {
 		p = prom_early_alloc(sizeof(struct property) + 32);
-		p->unique_id = prom_unique_id++;
+		inc_unique_id(p);
 	}
 
 	p->name = (char *) (p + 1);
@@ -53,27 +83,24 @@  static struct property * __init build_one_prop(phandle node, char *prev,
 		p->value = prom_early_alloc(special_len);
 		memcpy(p->value, special_val, special_len);
 	} else {
-		if (prev == NULL) {
-			name = prom_firstprop(node, p->name);
-		} else {
-			name = prom_nextprop(node, prev, p->name);
-		}
+		int err;
 
-		if (!name || strlen(name) == 0) {
+		if (prev == NULL)
+			err = prom_ops.firstprop(node, p->name);
+		else
+			err = prom_ops.nextprop(node, prev, p->name);
+		if (err) {
 			tmp = p;
 			return NULL;
 		}
-#ifdef CONFIG_SPARC32
-		strcpy(p->name, name);
-#endif
-		p->length = prom_getproplen(node, p->name);
+		p->length = prom_ops.getproplen(node, p->name);
 		if (p->length <= 0) {
 			p->length = 0;
 		} else {
 			int len;
 
 			p->value = prom_early_alloc(p->length + 1);
-			len = prom_getproperty(node, p->name, p->value,
+			len = prom_ops.getproperty(node, p->name, p->value,
 					       p->length);
 			if (len <= 0)
 				p->length = 0;
@@ -106,10 +133,10 @@  static char * __init get_one_property(phandle node, const char *name)
 	char *buf = "<NULL>";
 	int len;
 
-	len = prom_getproplen(node, name);
+	len = prom_ops.getproplen(node, name);
 	if (len > 0) {
 		buf = prom_early_alloc(len);
-		len = prom_getproperty(node, name, buf, len);
+		len = prom_ops.getproperty(node, name, buf, len);
 	}
 
 	return buf;
@@ -124,7 +151,7 @@  static struct device_node * __init prom_create_node(phandle node,
 		return NULL;
 
 	dp = prom_early_alloc(sizeof(*dp));
-	dp->unique_id = prom_unique_id++;
+	inc_unique_id(dp);
 	dp->parent = parent;
 
 	kref_init(&dp->kref);
@@ -140,13 +167,13 @@  static struct device_node * __init prom_create_node(phandle node,
 	return dp;
 }
 
-char * __init build_full_name(struct device_node *dp)
+static char * __init build_full_name(struct device_node *dp)
 {
 	int len, ourlen, plen;
 	char *n;
 
 	plen = strlen(dp->parent->full_name);
-	ourlen = strlen(dp->path_component_name);
+	ourlen = strlen(fetch_node_name(dp));
 	len = ourlen + plen + 2;
 
 	n = prom_early_alloc(len);
@@ -155,7 +182,7 @@  char * __init build_full_name(struct device_node *dp)
 		strcpy(n + plen, "/");
 		plen++;
 	}
-	strcpy(n + plen, dp->path_component_name);
+	strcpy(n + plen, fetch_node_name(dp));
 
 	return n;
 }
@@ -182,36 +209,39 @@  static struct device_node * __init prom_build_tree(struct device_node *parent,
 		*(*nextp) = dp;
 		*nextp = &dp->allnext;
 
+#if defined(CONFIG_SPARC)
 		dp->path_component_name = build_path_component(dp);
+#endif
 		dp->full_name = build_full_name(dp);
 
-		dp->child = prom_build_tree(dp, prom_getchild(node), nextp);
+		dp->child = prom_build_tree(dp, prom_ops.getchild(node), nextp);
 
 		if (prom_build_more)
 			prom_build_more(dp, nextp);
 
-		node = prom_getsibling(node);
+		node = prom_ops.getsibling(node);
 	}
 
 	return ret;
 }
 
-void __init prom_build_devicetree(void)
+void __init of_pdt_build_devicetree(int root_node)
 {
 	struct device_node **nextp;
 
-	allnodes = prom_create_node(prom_root_node, NULL);
+	allnodes = prom_create_node(root_node, NULL);
 	allnodes->path_component_name = "";
 	allnodes->full_name = "/";
 
 	nextp = &allnodes->allnext;
 	allnodes->child = prom_build_tree(allnodes,
-			prom_getchild(allnodes->phandle),
+			prom_ops.getchild(allnodes->phandle),
 			&nextp);
+}
 
-	of_console_init();
+void __init of_pdt_set_ops(struct of_pdt_ops *ops)
+{
+	BUG_ON(!ops);
 
-	printk("PROM: Built device tree with %u bytes of memory.\n",
-	       prom_early_allocated);
+	prom_ops = *ops;
 }
-
diff --git a/include/linux/of_pdt.h b/include/linux/of_pdt.h
new file mode 100644
index 0000000..1324ba5
--- /dev/null
+++ b/include/linux/of_pdt.h
@@ -0,0 +1,42 @@ 
+/*
+ * Definitions for building a device tree by calling into the
+ * Open Firmware PROM.
+ *
+ * Copyright (C) 2010  Andres Salomon <dilinger@queued.net>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _LINUX_OF_PDT_H
+#define _LINUX_OF_PDT_H
+
+extern void *prom_early_alloc(unsigned long size);
+
+/* overridable operations for calling into the PROM */
+struct of_pdt_ops {
+	/* buffers passed should be 32 bytes; return 0 on success */
+	int (*firstprop)(phandle node, char *buf);
+	int (*nextprop)(phandle node, const char *prev, char *buf);
+
+	/* for both functions, return proplen on success; -1 on error */
+	int (*getproplen)(phandle node, const char *prop);
+	int (*getproperty)(phandle node, const char *prop, char *buf,
+			int bufsize);
+
+	/* phandles are 0 if no child or sibling exists */
+	phandle (*getchild)(phandle parent);
+	phandle (*getsibling)(phandle node);
+};
+
+extern void of_pdt_set_ops(struct of_pdt_ops *ops);
+
+/* for building the device tree */
+extern void of_pdt_build_devicetree(int root_node);
+
+extern void (*prom_build_more)(struct device_node *dp,
+		struct device_node ***nextp);
+
+#endif /* _LINUX_OF_PDT_H */