Re: [PATCH 2/4] sparc: break out some prom device-tree building code out into drivers/of

Grant Likely
2010-06-29T07:50:31Z

On Mon, Jun 28, 2010 at 7:00 PM, Andres Salomon <dilinger@queued.net> wrote:
>
> Stick code into drivers/of/pdt.c (Prom Device Tree) that other
> architectures with OpenFirmware resident in memory can make use of.
>
> Signed-off-by: Andres Salomon <dilinger@queued.net>

Hi Andres,

The patch itself looks fine, but there are currently two methods for
extracting the device tree from open firmware; one in arch/powerpc
using the flattened format, and one in arch/sparc. I don't want to
end up maintaining both methods in drivers/of, and there has also some
discussions on moving the powerpc version into common code. I've been
thinking about using the powerpc approach to support ARM platforms
using both the flat tree and real OFW.

Ben, what say you? Before I do anything I'd like to have your opinion.

Cheers,
g.

> ---
>  arch/sparc/Kconfig              |    1 +
>  arch/sparc/include/asm/prom.h   |   15 +++-
>  arch/sparc/kernel/prom.h        |   14 ---
>  arch/sparc/kernel/prom_common.c |  173 +------------------------------
>  drivers/of/Kconfig              |    4 +
>  drivers/of/Makefile             |    1 +
>  drivers/of/pdt.c                |  225 +++++++++++++++++++++++++++++++++++++++
>  include/linux/of_pdt.h          |   37 +++++++
>  8 files changed, 282 insertions(+), 188 deletions(-)
>  create mode 100644 drivers/of/pdt.c
>  create mode 100644 include/linux/of_pdt.h
>
> diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
> index 6f1470b..b4cb63b 100644
> --- a/arch/sparc/Kconfig
> +++ b/arch/sparc/Kconfig
> @@ -150,6 +150,7 @@ config ARCH_NO_VIRT_TO_BUS
>
>  config OF
>        def_bool y
> +       select OF_PROMTREE
>
>  config ARCH_SUPPORTS_DEBUG_PAGEALLOC
>        def_bool y if SPARC64
> diff --git a/arch/sparc/include/asm/prom.h b/arch/sparc/include/asm/prom.h
> index f845828..0834c2a 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 +66,18 @@ 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);
> +/* stuff used by of/pdt */
> +extern void * prom_early_alloc(unsigned long size);
> +extern void irq_trans_init(struct device_node *dp);
> +extern char *build_path_component(struct device_node *dp);
> +
> +extern char *prom_firstprop(int node, char *buffer);
> +extern char *prom_nextprop(int node, const char *oprop, char *buffer);
> +extern int prom_getproplen(int node, const char *prop);
> +extern int prom_getproperty(int node, const char *prop,
> +                           char *buffer, int bufsize);
> +extern int prom_getchild(int node);
> +extern int prom_getsibling(int node);
>
>  #endif /* __KERNEL__ */
>  #endif /* _SPARC_PROM_H */
> diff --git a/arch/sparc/kernel/prom.h b/arch/sparc/kernel/prom.h
> index a8591ef..cf5fe1c 100644
> --- a/arch/sparc/kernel/prom.h
> +++ b/arch/sparc/kernel/prom.h
> @@ -4,20 +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;
> -
> -static inline int is_root_node(const struct device_node *dp)
> -{
> -       if (!dp)
> -               return 0;
> -
> -       return (dp->parent == NULL);
> -}
> -
> -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 57ac9e2..fc990e1 100644
> --- a/arch/sparc/kernel/prom_common.c
> +++ b/arch/sparc/kernel/prom_common.c
> @@ -20,14 +20,13 @@
>  #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>
>
>  #include "prom.h"
>
> -void (*prom_build_more)(struct device_node *dp, struct device_node ***nextp);
> -
>  struct device_node *of_console_device;
>  EXPORT_SYMBOL(of_console_device);
>
> @@ -119,176 +118,6 @@ int of_find_in_proplist(const char *list, const char *match, int len)
>  }
>  EXPORT_SYMBOL(of_find_in_proplist);
>
> -unsigned int prom_unique_id;
> -
> -static struct property * __init build_one_prop(phandle node, char *prev,
> -                                              char *special_name,
> -                                              void *special_val,
> -                                              int special_len)
> -{
> -       static struct property *tmp = NULL;
> -       struct property *p;
> -       const char *name;
> -
> -       if (tmp) {
> -               p = tmp;
> -               memset(p, 0, sizeof(*p) + 32);
> -               tmp = NULL;
> -       } else {
> -               p = prom_early_alloc(sizeof(struct property) + 32);
> -               p->unique_id = prom_unique_id++;
> -       }
> -
> -       p->name = (char *) (p + 1);
> -       if (special_name) {
> -               strcpy(p->name, special_name);
> -               p->length = special_len;
> -               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);
> -               }
> -
> -               if (!name || strlen(name) == 0) {
> -                       tmp = p;
> -                       return NULL;
> -               }
> -#ifdef CONFIG_SPARC32
> -               strcpy(p->name, name);
> -#endif
> -               p->length = prom_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,
> -                                              p->length);
> -                       if (len <= 0)
> -                               p->length = 0;
> -                       ((unsigned char *)p->value)[p->length] = '\0';
> -               }
> -       }
> -       return p;
> -}
> -
> -static struct property * __init build_prop_list(phandle node)
> -{
> -       struct property *head, *tail;
> -
> -       head = tail = build_one_prop(node, NULL,
> -                                    ".node", &node, sizeof(node));
> -
> -       tail->next = build_one_prop(node, NULL, NULL, NULL, 0);
> -       tail = tail->next;
> -       while(tail) {
> -               tail->next = build_one_prop(node, tail->name,
> -                                           NULL, NULL, 0);
> -               tail = tail->next;
> -       }
> -
> -       return head;
> -}
> -
> -static char * __init get_one_property(phandle node, const char *name)
> -{
> -       char *buf = "<NULL>";
> -       int len;
> -
> -       len = prom_getproplen(node, name);
> -       if (len > 0) {
> -               buf = prom_early_alloc(len);
> -               len = prom_getproperty(node, name, buf, len);
> -       }
> -
> -       return buf;
> -}
> -
> -static struct device_node * __init prom_create_node(phandle node,
> -                                                   struct device_node *parent)
> -{
> -       struct device_node *dp;
> -
> -       if (!node)
> -               return NULL;
> -
> -       dp = prom_early_alloc(sizeof(*dp));
> -       dp->unique_id = prom_unique_id++;
> -       dp->parent = parent;
> -
> -       kref_init(&dp->kref);
> -
> -       dp->name = get_one_property(node, "name");
> -       dp->type = get_one_property(node, "device_type");
> -       dp->phandle = node;
> -
> -       dp->properties = build_prop_list(node);
> -
> -       irq_trans_init(dp);
> -
> -       return dp;
> -}
> -
> -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);
> -       len = ourlen + plen + 2;
> -
> -       n = prom_early_alloc(len);
> -       strcpy(n, dp->parent->full_name);
> -       if (!is_root_node(dp->parent)) {
> -               strcpy(n + plen, "/");
> -               plen++;
> -       }
> -       strcpy(n + plen, dp->path_component_name);
> -
> -       return n;
> -}
> -
> -static struct device_node * __init prom_build_tree(struct device_node *parent,
> -                                                  phandle node,
> -                                                  struct device_node ***nextp)
> -{
> -       struct device_node *ret = NULL, *prev_sibling = NULL;
> -       struct device_node *dp;
> -
> -       while (1) {
> -               dp = prom_create_node(node, parent);
> -               if (!dp)
> -                       break;
> -
> -               if (prev_sibling)
> -                       prev_sibling->sibling = dp;
> -
> -               if (!ret)
> -                       ret = dp;
> -               prev_sibling = dp;
> -
> -               *(*nextp) = dp;
> -               *nextp = &dp->allnext;
> -
> -               dp->path_component_name = build_path_component(dp);
> -               dp->full_name = build_full_name(dp);
> -
> -               dp->child = prom_build_tree(dp, prom_getchild(node), nextp);
> -
> -               if (prom_build_more)
> -                       prom_build_more(dp, nextp);
> -
> -               node = prom_getsibling(node);
> -       }
> -
> -       return ret;
> -}
> -
>  unsigned int prom_early_allocated __initdata;
>
>  void __init prom_build_devicetree(void)
> diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
> index 7cecc8f..41921a8 100644
> --- a/drivers/of/Kconfig
> +++ b/drivers/of/Kconfig
> @@ -2,6 +2,10 @@ 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
> new file mode 100644
> index 0000000..b24167f
> --- /dev/null
> +++ b/drivers/of/pdt.c
> @@ -0,0 +1,225 @@
> +/*
> + * Paul Mackerras      August 1996.
> + * Copyright (C) 1996-2005 Paul Mackerras.
> + *
> + *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
> + *    {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
> + *      as published by the Free Software Foundation; either version
> + *      2 of the License, or (at your option) any later version.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/errno.h>
> +#include <linux/mutex.h>
> +#include <linux/slab.h>
> +#include <linux/of.h>
> +#include <linux/of_pdt.h>
> +#include <asm/prom.h>
> +
> +/* TODO: mark this stuff as __initdata */
> +void (*prom_build_more)(struct device_node *dp, struct device_node ***nextp);
> +
> +#if defined(CONFIG_SPARC)
> +static unsigned int prom_unique_id;
> +
> +#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
> +
> +#define inc_unique_id(p)       do { } while(0)
> +
> +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 */
> +}
> +
> +#endif /* !CONFIG_SPARC */
> +
> +static struct property * __init build_one_prop(phandle node, char *prev,
> +                                              char *special_name,
> +                                              void *special_val,
> +                                              int special_len)
> +{
> +       static struct property *tmp = NULL;
> +       struct property *p;
> +       const char *name;
> +
> +       if (tmp) {
> +               p = tmp;
> +               memset(p, 0, sizeof(*p) + 32);
> +               tmp = NULL;
> +       } else {
> +               p = prom_early_alloc(sizeof(struct property) + 32);
> +               inc_unique_id(p);
> +       }
> +
> +       p->name = (char *) (p + 1);
> +       if (special_name) {
> +               strcpy(p->name, special_name);
> +               p->length = special_len;
> +               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);
> +               }
> +
> +               if (!name || strlen(name) == 0) {
> +                       tmp = p;
> +                       return NULL;
> +               }
> +#ifdef CONFIG_SPARC32
> +               strcpy(p->name, name);
> +#endif
> +               p->length = prom_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,
> +                                              p->length);
> +                       if (len <= 0)
> +                               p->length = 0;
> +                       ((unsigned char *)p->value)[p->length] = '\0';
> +               }
> +       }
> +       return p;
> +}
> +
> +static struct property * __init build_prop_list(phandle node)
> +{
> +       struct property *head, *tail;
> +
> +       head = tail = build_one_prop(node, NULL,
> +                                    ".node", &node, sizeof(node));
> +
> +       tail->next = build_one_prop(node, NULL, NULL, NULL, 0);
> +       tail = tail->next;
> +       while(tail) {
> +               tail->next = build_one_prop(node, tail->name,
> +                                           NULL, NULL, 0);
> +               tail = tail->next;
> +       }
> +
> +       return head;
> +}
> +
> +static char * __init get_one_property(phandle node, const char *name)
> +{
> +       char *buf = "<NULL>";
> +       int len;
> +
> +       len = prom_getproplen(node, name);
> +       if (len > 0) {
> +               buf = prom_early_alloc(len);
> +               len = prom_getproperty(node, name, buf, len);
> +       }
> +
> +       return buf;
> +}
> +
> +struct device_node * __init prom_create_node(phandle node,
> +                                            struct device_node *parent)
> +{
> +       struct device_node *dp;
> +
> +       if (!node)
> +               return NULL;
> +
> +       dp = prom_early_alloc(sizeof(*dp));
> +       inc_unique_id(dp);
> +       dp->parent = parent;
> +
> +       kref_init(&dp->kref);
> +
> +       dp->name = get_one_property(node, "name");
> +       dp->type = get_one_property(node, "device_type");
> +       dp->phandle = node;
> +
> +       dp->properties = build_prop_list(node);
> +
> +       irq_trans_init(dp);
> +
> +       return 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(fetch_node_name(dp));
> +       len = ourlen + plen + 2;
> +
> +       n = prom_early_alloc(len);
> +       strcpy(n, dp->parent->full_name);
> +       if (!is_root_node(dp->parent)) {
> +               strcpy(n + plen, "/");
> +               plen++;
> +       }
> +       strcpy(n + plen, fetch_node_name(dp));
> +
> +       return n;
> +}
> +
> +struct device_node * __init prom_build_tree(struct device_node *parent,
> +                                           phandle node,
> +                                           struct device_node ***nextp)
> +{
> +       struct device_node *ret = NULL, *prev_sibling = NULL;
> +       struct device_node *dp;
> +
> +       while (1) {
> +               dp = prom_create_node(node, parent);
> +               if (!dp)
> +                       break;
> +
> +               if (prev_sibling)
> +                       prev_sibling->sibling = dp;
> +
> +               if (!ret)
> +                       ret = dp;
> +               prev_sibling = dp;
> +
> +               *(*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);
> +
> +               if (prom_build_more)
> +                       prom_build_more(dp, nextp);
> +
> +               node = prom_getsibling(node);
> +       }
> +
> +       return ret;
> +}
> diff --git a/include/linux/of_pdt.h b/include/linux/of_pdt.h
> new file mode 100644
> index 0000000..f62616e
> --- /dev/null
> +++ b/include/linux/of_pdt.h
> @@ -0,0 +1,37 @@
> +#include <linux/of.h>  /* linux/of.h gets to determine #include ordering */
> +/*
> + * Definitions for building a device tree by calling into the
> + * Open Firmware PROM.
> + *
> + * Copyright (C) 1996-2005 Paul Mackerras.
> + * Copyright (C) 2010  Andres Salomon <dilinger@queued.net>
> + *
> + * Updates for PPC64 by Peter Bergner & David Engebretsen, IBM Corp.
> + * Updates for SPARC by David S. Miller
> + *
> + * 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 struct device_node *prom_create_node(phandle node,
> +                                           struct device_node *parent);
> +extern struct device_node *prom_build_tree(struct device_node *parent,
> +                                          phandle node,
> +                                          struct device_node ***nextp);
> +
> +extern void (*prom_build_more)(struct device_node *dp, struct device_node ***nextp);
> +
> +static inline int is_root_node(const struct device_node *dp)
> +{
> +       if (!dp)
> +               return 0;
> +
> +       return (dp->parent == NULL);
> +}
> +
> +#endif /* _LINUX_OF_PDT_H */
> --
> 1.5.6.5
>
>

--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.