RFC: OLPC/x86 device tree code

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 <[email protected]>

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 <[email protected]>

---
 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

arch/sparc/Kconfig +0 -0

index 6f1470b..b4cb63b 100644
@@ -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

arch/sparc/include/asm/prom.h +13 -2

index f845828..0834c2a 100644
@@ -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 */

arch/sparc/kernel/prom.h +0 -14

index a8591ef..cf5fe1c 100644
@@ -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;

arch/sparc/kernel/prom_common.c +1 -172

index 57ac9e2..fc990e1 100644
@@ -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)

drivers/of/Kconfig +0 -0

index 7cecc8f..41921a8 100644
@@ -2,6 +2,10 @@ config OF_FLATTREE

       bool
       depends on OF

drivers/of/Kconfig +4 -0

+config OF_PROMTREE
+       bool
+       depends on OF
+

 config OF_DYNAMIC
       def_bool y
       depends on OF && PPC_OF

drivers/of/Makefile +0 -0

index f232cc9..54e8517 100644
@@ -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

drivers/of/pdt.c new file +225 -0

new file mode 100644
index 0000000..b24167f
@@ -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 [email protected]
+ *  Adapted for multiple architectures by Andres Salomon <[email protected]>
+ *
+ *      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;
+}

include/linux/of_pdt.h new file +37 -1

new file mode 100644
index 0000000..f62616e
@@ -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 <[email protected]>
+ *
+ * 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

Quoted 5 lines · Andres Salomon

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 <[email protected]>

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.

Quoted 17 lines · On Tue, 29 Jun 2010 00:50:08 -0700 Grant Likely <[email protected]>…

Quoted 5 lines · Andres Salomon

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 <[email protected]>

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.

Quoted 2 lines

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

So you're saying that you want ARM (and sparc, and OLPC) to generate a flat tree by calling into OFW?

Sparc and OLPC have very similar
mechanisms for getting device tree info from OFW, so it makes sense to share code between them.

On Tue, Jun 29, 2010 at 9:03 AM, Andres Salomon <[email protected]> wrote:

Quoted 4 lines

Sparc and OLPC have very similar
mechanisms for getting device tree info from OFW, so it makes sense to share code between them.

Other than the flattened tree step; is the powerpc method dissimilar from the Sparc and OLPC method for talking to OFW? (This is not a rhetorical question, I'm want to know if I'm missing some details). The main difference I know about is that OFW can still kept alive at runtime for sparc, which powerpc does not do. However, keeping OFW callable is a separate issue from how to extract the device tree.

Quoted 2 lines · On Tue, 29 Jun 2010 15:42:54 -0600 Grant Likely <[email protected]>…

On Tue, Jun 29, 2010 at 9:03 AM, Andres Salomon <[email protected]> wrote:

[...]

Quoted 5 lines

Quoted 4 lines

 Sparc and OLPC have very similar
mechanisms for getting device tree info from OFW, so it makes sense to share code between them.

Quoted 7 lines

Other than the flattened tree step; is the powerpc method dissimilar from the Sparc and OLPC method for talking to OFW?  (This is not a rhetorical question, I'm want to know if I'm missing some details). The main difference I know about is that OFW can still kept alive at runtime for sparc, which powerpc does not do.  However, keeping OFW callable is a separate issue from how to extract the device tree.

After having a look at powerpc's flatten_device_tree, I don't see any obvious reason why OLPC couldn't use this

(though it still strikes me
as weird to go from prom->fdt->dt when the option of prom->dt is available and less complex).

Do you already have the patches that put
this into drivers/of/?

Quoted 20 lines · Andres Salomon

Quoted 2 lines · On Tue, 29 Jun 2010 15:42:54 -0600 Grant Likely <[email protected]>…

On Tue, Jun 29, 2010 at 9:03 AM, Andres Salomon
<[email protected]> wrote:

[...]

Quoted 5 lines

Quoted 4 lines

 Sparc and OLPC have very similar
mechanisms for getting device tree info from OFW, so it makes sense to share code between them.

Quoted 8 lines

Other than the flattened tree step; is the powerpc method dissimilar from the Sparc and OLPC method for talking to OFW? (This is not a rhetorical question, I'm want to know if I'm missing some details). The main difference I know about is that OFW can still kept alive at runtime for sparc, which powerpc does not do.  However, keeping OFW callable is a separate issue from how to extract the device tree.

Quoted 2 lines

After having a look at powerpc's flatten_device_tree, I don't see any obvious reason why OLPC couldn't use this

Okay.

Quoted 3 lines

(though it still strikes me
as weird to go from prom->fdt->dt when the option of prom->dt is available and less complex).

Which is why I didn't simply NACK it out of hand. It is a valid point.

I'd probably be happier if both fdt and pdt used a shared set of utility functions for allocating and tying together the device_node data structures. Then at least there would be only one instance of code to deal with the fiddly data structure interconnections.

The nice thing about the powerpc version is that the tree can be extracted really early in the boot process, before any of the core kernel infrastructure or memory management is initialized.

- For the pdt, calling into the prom once for each property/node to create a fdt, and then unflattening it. This is better than the previous option, but I don't think the prom->fdt code will be very nice.

From: Andres Salomon <[email protected]>
Date: Wed, 7 Jul 2010 04:07:34 +0000

Quoted 4 lines

- For the pdt, calling into the prom once for each property/node to create a fdt, and then unflattening it. This is better than the previous option, but I don't think the prom->fdt code will be
very nice.

I'll need this on sparc64 at some point to support kexec() anyways.

So at least for sparc you can assume that a something-->fdt translator is going to exist at some point in the future regardless of what happens here.

Sounds like we have a winner. I'll concentrate on that, thanks for the heads up.

From: Andres Salomon <[email protected]>
Date: Wed, 7 Jul 2010 04:07:34 +0000

Quoted 4 lines

- For the pdt, calling into the prom once for each property/node to create a fdt, and then unflattening it. This is better than the previous option, but I don't think the prom->fdt code will be
very nice.

I'll need this on sparc64 at some point to support kexec() anyways.

So at least for sparc you can assume that a something-->fdt translator is going to exist at some point in the future regardless of what happens here.

From: Andres Salomon <[email protected]>
Date: Wed, 7 Jul 2010 04:07:34 +0000

Quoted 4 lines

- For the pdt, calling into the prom once for each property/node to create a fdt, and then unflattening it. This is better than the previous option, but I don't think the prom->fdt code will be
very nice.

I'll need this on sparc64 at some point to support kexec() anyways.

So at least for sparc you can assume that a something-->fdt translator is going to exist at some point in the future regardless of what happens here.

From: Andres Salomon <[email protected]>
Date: Wed, 7 Jul 2010 04:07:34 +0000

Quoted 4 lines

 - For the pdt, calling into the prom once for each property/node to create a fdt, and then unflattening it.  This is better than the previous option, but I don't think the prom->fdt code will be very nice.

I'll need this on sparc64 at some point to support kexec() anyways.

So at least for sparc you can assume that a something-->fdt translator is going to exist at some point in the future regardless of what happens here.

I'm curious... what are your plans here? Will you be keeping OF alive between kexec()? Will the new kernel get the entire device tree from fdt, or will it still be talking to OF? How will the fdt fragments as Andres described above fit into sparc kexec (as opposed to generating one big tree as in his first option)?

From: Grant Likely <[email protected]>
Date: Tue, 6 Jul 2010 01:00:06 -0600

Quoted 5 lines

I'm curious... what are your plans here?  Will you be keeping OF alive between kexec()?  Will the new kernel get the entire device tree from fdt, or will it still be talking to OF?  How will the fdt fragments as Andres described above fit into sparc kexec (as opposed to generating one big tree as in his first option)?

On certain sparc64 systems, I have to stop making PROM calls early in the boot right after I fetch the device tree into the kernel.

So yes for a kexec() I'll have to pass an fdt or similar to the child kernel.

It could be a big linear fdt buffer, or fragments, it really doesn't matter all that much actually.

On Wed, 30 Jun 2010 15:52:51 -0600
Grant Likely <[email protected]> wrote:
 - For the pdt, calling into the prom twice for each property/node, getting the size of everything during the first tree traversal, allocating memory, and then creating the tree during the second traversal. This is slow and I don't see much point to it.

 - For the pdt, calling into the prom once for each property/node to create a fdt, and then unflattening it.  This is better than the previous option, but I don't think the prom->fdt code will be very nice.

 - Changing the fdt code to allocate memory more dynamically; rather than a first run through the fdt to determine the unflattened tree size, simply allocate memory chunks as we run through the tree. Memory might still be backed the same way (calling early_init_dt_alloc_memory_arch to grab a chunk of memory, and then allocating chunks of it via unflatten_dt_alloc), but the difference would be that it wouldn't necessarily be contiguous, and in how it's

  done.  For example, early_init_dt_alloc_memory_arch might be called initially to allocate a 16k chunk, and once unflatten_dt_alloc runs out of memory in that chunk, another 16k chunk might be allocated. This would also translate to sparc's prom_early_alloc being used to allocate the chunk, and then node/property structs being allocated from those chunks.  (The 16k choice
  is completely arbitrary; people more familiar w/ the early memory setup of ppc/sparc might have a better suggestion)

Quoted 20 lines · Andres Salomon

Quoted 2 lines · On Tue, 29 Jun 2010 15:42:54 -0600 Grant Likely <[email protected]>…

On Tue, Jun 29, 2010 at 9:03 AM, Andres Salomon
<[email protected]> wrote:

[...]

Quoted 5 lines

Quoted 4 lines

 Sparc and OLPC have very similar
mechanisms for getting device tree info from OFW, so it makes sense to share code between them.

Quoted 8 lines

Other than the flattened tree step; is the powerpc method dissimilar from the Sparc and OLPC method for talking to OFW? (This is not a rhetorical question, I'm want to know if I'm missing some details). The main difference I know about is that OFW can still kept alive at runtime for sparc, which powerpc does not do.  However, keeping OFW callable is a separate issue from how to extract the device tree.

Quoted 2 lines

After having a look at powerpc's flatten_device_tree, I don't see any obvious reason why OLPC couldn't use this

Okay.

Quoted 3 lines

(though it still strikes me
as weird to go from prom->fdt->dt when the option of prom->dt is available and less complex).

Which is why I didn't simply NACK it out of hand. It is a valid point.

I'd probably be happier if both fdt and pdt used a shared set of utility functions for allocating and tying together the device_node data structures. Then at least there would be only one instance of code to deal with the fiddly data structure interconnections.

The nice thing about the powerpc version is that the tree can be extracted really early in the boot process, before any of the core kernel infrastructure or memory management is initialized.

Quoted 20 lines · Andres Salomon

Quoted 2 lines · On Tue, 29 Jun 2010 15:42:54 -0600 Grant Likely <[email protected]>…

On Tue, Jun 29, 2010 at 9:03 AM, Andres Salomon
<[email protected]> wrote:

[...]

Quoted 5 lines

Quoted 4 lines

 Sparc and OLPC have very similar
mechanisms for getting device tree info from OFW, so it makes sense to share code between them.

Quoted 8 lines

Other than the flattened tree step; is the powerpc method dissimilar from the Sparc and OLPC method for talking to OFW? (This is not a rhetorical question, I'm want to know if I'm missing some details). The main difference I know about is that OFW can still kept alive at runtime for sparc, which powerpc does not do.  However, keeping OFW callable is a separate issue from how to extract the device tree.

Quoted 2 lines

After having a look at powerpc's flatten_device_tree, I don't see any obvious reason why OLPC couldn't use this

Okay.

Quoted 3 lines

(though it still strikes me
as weird to go from prom->fdt->dt when the option of prom->dt is available and less complex).

Which is why I didn't simply NACK it out of hand. It is a valid point.

I'd probably be happier if both fdt and pdt used a shared set of utility functions for allocating and tying together the device_node data structures. Then at least there would be only one instance of code to deal with the fiddly data structure interconnections.

The nice thing about the powerpc version is that the tree can be extracted really early in the boot process, before any of the core kernel infrastructure or memory management is initialized.

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 <[email protected]>

---
 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

arch/sparc/Kconfig +0 -0

index 6f1470b..b4cb63b 100644
@@ -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

arch/sparc/include/asm/prom.h +3 -2

index f845828..0834c2a 100644
@@ -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);

drivers/of/pdt.c new file +17 -0

new file mode 100644
index 0000000..b24167f
@@ -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 [email protected]
+ *  Adapted for multiple architectures by Andres Salomon <[email protected]>
+ *
+ *      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>

drivers/of/pdt.c new file +6 -0

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

drivers/of/pdt.c new file +7 -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)

drivers/of/pdt.c new file +155 -0

+{
+       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);
+

include/linux/of_pdt.h new file +24 -0

+/*
+ * Definitions for building a device tree by calling into the
+ * Open Firmware PROM.
+ *
+ * Copyright (C) 1996-2005 Paul Mackerras.
+ * Copyright (C) 2010  Andres Salomon <[email protected]>
+ *
+ * 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);

Quoted 5 lines · Andres Salomon

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 <[email protected]>

Some more comments below...

Quoted 50 lines

 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

arch/sparc/Kconfig +0 -0

index 6f1470b..b4cb63b 100644
@@ -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

(quoted diff) +0 -0

b/arch/sparc/include/asm/prom.h index f845828..0834c2a 100644

arch/sparc/include/asm/prom.h +1 -1

@@ -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 */

arch/sparc/include/asm/prom.h +6 -0

+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);

arch/sparc/include/asm/prom.h extern struct device_node *of_console_device; · line 80

Quoted 4 lines

arch/sparc/include/asm/prom.h +4 -0

+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);

These become the API required by of/pdt. They should be defined in a arch-independent header file. Something like include/linux/of_pdt.h

Right now only OLPC will be using this, so static function definitions are just fine. However, if there is ever more than one method for talking to OFW, then these hooks will need to be converted into an ops structure so the right one can be passed in at runtime.

Quoted 8 lines

include/linux/of_pdt.h new file +1 -0

new file mode 100644
index 0000000..f62616e
@@ -0,0 +1,37 @@
+#include <linux/of.h>  /* linux/of.h gets to determine #include

ordering */

Do you really need this #include in this way? Can it be moved inside the #ifndef OF_PDT block below?

Another general comment, I'm still not thrilled with this code having its own independent method for building the tree, but I doubt the existing add/remove nodes and properties code is usable early enough to be suitable for sparc. How early do you extract the device tree on OLPC? How are you going to use the data?

Quoted 10 lines · On Tue, 6 Jul 2010 03:21:21 -0600 Grant Likely…

Quoted 5 lines · Andres Salomon

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 <[email protected]>

Some more comments below...

Thanks for the review!

Quoted 58 lines

Quoted 50 lines

 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

arch/sparc/Kconfig +0 -0

index 6f1470b..b4cb63b 100644
@@ -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

(quoted diff) +0 -0

b/arch/sparc/include/asm/prom.h index f845828..0834c2a 100644

arch/sparc/include/asm/prom.h +1 -1

@@ -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 */

arch/sparc/include/asm/prom.h +6 -0

+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);

arch/sparc/include/asm/prom.h extern struct device_node *of_console_device; · line 80

Quoted 4 lines

arch/sparc/include/asm/prom.h +4 -0

+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);

These become the API required by of/pdt.  They should be defined in a arch-independent header file.  Something like include/linux/of_pdt.h

Quoted 5 lines

Right now only OLPC will be using this, so static function definitions are just fine.  However, if there is ever more than one method for talking to OFW, then these hooks will need to be converted into an ops structure so the right one can be passed in at runtime.

Note that sparc and OLPC actually use slightly different function signatures; OLPC uses phandles for nodes, while sparc uses ints.  Not a huge difference, but enough that I didn't want to mess w/ a generic version of it early in the process.

 I agree that op structs would be
nicer, and will probably move towards that.

[...]

Quoted 12 lines

Quoted 8 lines

include/linux/of_pdt.h new file +1 -0

new file mode 100644
index 0000000..f62616e
@@ -0,0 +1,37 @@
+#include <linux/of.h>  /* linux/of.h gets to determine #include

ordering */

Do you really need this #include in this way?  Can it be moved inside the #ifndef OF_PDT block below?

Not sure, will try out different variants and see what breaks.

[...]

Quoted 5 lines

Another general comment, I'm still not thrilled with this code having its own independent method for building the tree, but I doubt the existing add/remove nodes and properties code is usable early enough to be suitable for sparc.  How early do you extract the device tree on OLPC?  How are you going to use the data?

Not that early; very early code fetches information necessary to call into the PROM, and ensures that the kernel doesn't clobber OFW's memory.   After that, we can build the dt at any point during init. The data is to be exported via proc for userspace to use in determining hardware (and firmware) info.

Okay, so it is only the userspace interface that you're interested in, correct? You have no needs/plans (as of yet) to register devices out of the device tree?

Microblaze and PPC both use PROC_DEVICETREE, and OLPC will as well.. put the Kconfig option into fs/ rather than in arch/*/Kconfig.

Signed-off-by Andres Salomon <[email protected]>

---
 arch/microblaze/Kconfig |    8 --------
 arch/powerpc/Kconfig    |    8 --------
 fs/proc/Kconfig         |    8 ++++++++

 3 files changed, 8 insertions(+), 16 deletions(-)

arch/microblaze/Kconfig +0 -0

index 76818f9..b66c962 100644
@@ -128,14 +128,6 @@ config OF

       def_bool y
       select OF_FLATTREE

arch/microblaze/Kconfig +0 -8

-config PROC_DEVICETREE
-       bool "Support for device tree in /proc"
-       depends on PROC_FS
-       help
-         This option adds a device-tree directory under /proc which contains
-         an image of the device tree that the kernel copies from Open
-         Firmware or other boot firmware. If unsure, say Y here.
-

 endmenu

 menu "Advanced setup"

arch/powerpc/Kconfig +0 -0

index 328774b..8a56e8b 100644
@@ -578,14 +578,6 @@ config SCHED_SMT

         when dealing with POWER5 cpus at a cost of slightly increased overhead in some places. If unsure say N here.

arch/powerpc/Kconfig +0 -8

-config PROC_DEVICETREE
-       bool "Support for device tree in /proc"
-       depends on PROC_FS
-       help
-         This option adds a device-tree directory under /proc which contains
-         an image of the device tree that the kernel copies from Open
-         Firmware or other boot firmware. If unsure, say Y here.
-

 config CMDLINE_BOOL
       bool "Default bootloader kernel arguments"

fs/proc/Kconfig +0 -0

index 50f8f06..858a859 100644
@@ -39,6 +39,14 @@ config PROC_VMCORE

        help
        Exports the dump image of crashed kernel in ELF format.

Make use of PROC_DEVICETREE to export the tree, and sparc's PROMTREE code to call into OLPC's Open Firmware to build the tree.

(Yes, I know this leaks memory by simply using kmalloc)

Signed-off-by Andres Salomon <[email protected]>

---
 arch/x86/Kconfig                 |    5 ++ arch/x86/include/asm/olpc_prom.h |   42 +++++++++++ arch/x86/include/asm/prom.h      |    5 ++ arch/x86/kernel/Makefile         |    1 + arch/x86/kernel/olpc_ofw.c       |   13 ++++ arch/x86/kernel/olpc_prom.c      |  148 ++++++++++++++++++++++++++++++++++++++ fs/proc/Kconfig                  |    2 +-

 7 files changed, 215 insertions(+), 1 deletions(-)

 create mode 100644 arch/x86/include/asm/olpc_prom.h create mode 100644 arch/x86/include/asm/prom.h create mode 100644 arch/x86/kernel/olpc_prom.c

arch/x86/Kconfig +0 -0

index 71c194d..7aea004 100644
@@ -2071,6 +2071,11 @@ config OLPC_OPENFIRMWARE

         that is used on the OLPC XO-1 Children's Machine. If unsure, say N here.

 endif # X86_32

 config K8_NB

arch/x86/include/asm/olpc_prom.h new file +13 -0

new file mode 100644
index 0000000..96cdcee
@@ -0,0 +1,42 @@
+#include <linux/of.h>  /* linux/of.h gets to determine #include ordering */
+/*
+ * Definitions for talking to the Open Firmware PROM on
+ * Power Macintosh computers.
+ *
+ * Copyright (C) 1996-2005 Paul Mackerras.
+ *
+ * Updates for PPC64 by Peter Bergner & David Engebretsen, IBM Corp.
+ * Updates for SPARC by David S. Miller
+ * Updates for x86/OLPC by Andres Salomon
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License

arch/x86/include/asm/olpc_prom.h new file +14 -0

+extern void prom_build_devicetree(void);
+
+extern void *prom_early_alloc(unsigned long size);
+
+extern char *prom_firstprop(phandle node, char *buf);
+extern char *prom_nextprop(phandle node, const char *prev, char *buf);
+extern int prom_getproplen(phandle node, const char *prop);
+extern int prom_getproperty(phandle node, const char *prop,
+                            char *buffer, int bufsize);
+extern phandle prom_getchild(phandle node);
+extern phandle prom_getsibling(phandle node);
+
+#endif /* __KERNEL__ */
+#endif /* _X86_PROM_OLPC_H */

arch/x86/include/asm/prom.h new file +0 -0

new file mode 100644
index 0000000..7b561b2

arch/x86/kernel/Makefile +0 -0

index 0925676..3d7e535 100644
@@ -105,6 +105,7 @@ scx200-y                    += scx200_32.o
 

 obj-$(CONFIG_OLPC)             += olpc.o obj-$(CONFIG_OLPC_OPENFIRMWARE)        += olpc_ofw.o +obj-$(CONFIG_PROC_DEVICETREE)  += olpc_prom.o obj-$(CONFIG_X86_MRST)         += mrst.o

 microcode-y                            := microcode_core.o

arch/x86/kernel/olpc_ofw.c +13 -0

index 3e13a4b..8838edb 100644
@@ -6,6 +6,7 @@
  #include <asm/io.h>
  #include <asm/pgtable.h>
  #include <asm/olpc_ofw.h>
+#include <asm/prom.h>
 
  /* address of OFW callback interface; will be NULL if OFW isn't found */
  static int (*olpc_ofw_cif)(int *);

@@ -103,3 +104,15 @@ void __init olpc_ofw_detect(void)
                        (unsigned long)olpc_ofw_cif, (-start) >> 20);
        reserve_top_address(-start);
  }
+
+#ifdef CONFIG_PROC_DEVICETREE
+static int __init olpc_ofw_build_devicetree(void)
+{
+       /* initialize the device-tree that proc uses */
+       if (olpc_ofw_cif)
+               prom_build_devicetree();
+
+       return 0;
+}
+arch_initcall(olpc_ofw_build_devicetree);
+#endif /* CONFIG_PROC_DEVICETREE */

arch/x86/kernel/olpc_prom.c new file +148 -0

new file mode 100644
index 0000000..1128f3f
@@ -0,0 +1,148 @@
+/*
+ * olpc_prom.c: OLPC-specific OFW device tree support code.
+ *
+ * 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 [email protected]
+ *
+ *      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/slab.h>
+#include <linux/of.h>
+#include <linux/of_pdt.h>
+#include <asm/olpc_ofw.h>
+#include <asm/prom.h>
+
+phandle prom_getsibling(phandle node)
+{
+       const void *args[] = { (void *)node };
+       void *res[] = { &node };
+
+       if (node == -1)
+               return -1;
+
+       if (olpc_ofw("peer", args, res) || node == -1)
+               return -1;
+
+       return node;
+}
+
+phandle prom_getchild(phandle node)
+{
+       const void *args[] = { (void *)node };
+       void *res[] = { &node };
+
+       if (node == -1)
+               return 0;
+
+       if (olpc_ofw("child", args, res) || node == -1) {
+               printk(KERN_ERR "PROM: %s: fetching child failed!\n", __func__);
+               return 0;
+       }
+
+       return node;
+}
+
+int prom_getproplen(phandle node, const char *prop)
+{
+       const void *args[] = { (void *)node, prop };
+       int len;
+       void *res[] = { &len };
+
+       if (node == -1)
+               return 0;
+
+       if (olpc_ofw("getproplen", args, res)) {
+               printk(KERN_ERR "PROM: %s: getproplen failed!\n", __func__);
+               return 0;
+       }
+
+       return len;
+}
+
+int prom_getproperty(phandle node, const char *prop, char *buf,
+               int bufsize)
+{
+       int plen;
+
+       plen = prom_getproplen(node, prop);
+       if (plen > bufsize || plen < 1)
+               return -1;
+       else {
+               const void *args[] = { (void *)node, prop, buf, (void *)plen };
+               void *res[] = { &plen };
+
+               if (olpc_ofw("getprop", args, res)) {
+                       printk(KERN_ERR "PROM: %s: getprop failed!\n", __func__);
+                       return -1;
+               }
+               //((unsigned char *)buf)[plen] = '\0';
+       }
+
+       return 0;
+}
+
+char *prom_firstprop(phandle node, char *buf)
+{
+       buf[0] = '\0';
+
+       if (node == -1)
+               return NULL;
+
+       return prom_nextprop(node, "", buf);
+}
+
+char *prom_nextprop(phandle node, const char *prev, char *buf)
+{
+       const void *args[] = { (void *)node, prev, buf };
+       int success;
+       void *res[] = { &success };
+
+       buf[0] = '\0';
+
+       if (node == -1)
+               return NULL;
+
+       if (olpc_ofw("nextprop", args, res) || success != 1) {
+               printk(KERN_ERR "PROM: %s: nextprop failed!\n", __func__);
+               return NULL;
+       }
+
+       return buf;
+}
+
+void * __init prom_early_alloc(unsigned long size)
+{
+       /* unlike SPARC, we don't bother keeping track of prom memory */
+       return kzalloc(size, GFP_KERNEL);
+}
+
+void __init prom_build_devicetree(void)
+{
+       struct device_node **nextp;
+       phandle root;
+
+       root = prom_getsibling(0);
+       if (root < 0) {
+               printk(KERN_ERR "PROM: unable to get root node from OFW!\n");
+               return;
+       }
+
+       allnodes = prom_create_node(root, NULL);
+       allnodes->full_name = "/";
+
+       nextp = &allnodes->allnext;
+       allnodes->child = prom_build_tree(allnodes,
+                       prom_getchild(allnodes->phandle), &nextp);
+}

fs/proc/Kconfig +0 -0

index 858a859..86f67ce 100644
@@ -41,7 +41,7 @@ config PROC_VMCORE
 

 config PROC_DEVICETREE
       bool "Support for device tree in /proc"

-       depends on PROC_FS && (PPC || MICROBLAZE)
+       depends on PROC_FS && (PPC || MICROBLAZE || OLPC_OPENFIRMWARE)

Quoted 9 lines

arch/x86/Kconfig +0 -0

index 71c194d..7aea004 100644
@@ -2071,6 +2071,11 @@ config OLPC_OPENFIRMWARE

         that is used on the OLPC XO-1 Children's Machine. If unsure, say N here.

arch/x86/Kconfig config OLPC_OPENFIRMWARE · line 2078

Quoted 5 lines

arch/x86/Kconfig +5 -0

+config OF
+       def_bool y
+       depends on OLPC_OPENFIRMWARE
+       select OF_PROMTREE
+

This hunk will need to be respun on top of Stephen's CONFIG_OF change.
It's currently in my test-devicetree branch on
git://git.secretlab.ca/git/linux-2.6

Hi Andres, comments below....

Quoted 28 lines · Andres Salomon

Make use of PROC_DEVICETREE to export the tree, and sparc's PROMTREE code to call into OLPC's Open Firmware to build the tree.

(Yes, I know this leaks memory by simply using kmalloc)

Signed-off-by Andres Salomon <[email protected]>

---
 arch/x86/Kconfig                 |    5 ++ arch/x86/include/asm/olpc_prom.h |   42 +++++++++++ arch/x86/include/asm/prom.h      |    5 ++ arch/x86/kernel/Makefile         |    1 + arch/x86/kernel/olpc_ofw.c       |   13 ++++ arch/x86/kernel/olpc_prom.c      |  148 ++++++++++++++++++++++++++++++++++++++ fs/proc/Kconfig |    2 +- 7 files changed, 215 insertions(+), 1 deletions(-) create mode 100644 arch/x86/include/asm/olpc_prom.h create mode 100644 arch/x86/include/asm/prom.h
 create mode 100644 arch/x86/kernel/olpc_prom.c

arch/x86/Kconfig +0 -0

index 71c194d..7aea004 100644
@@ -2071,6 +2071,11 @@ config OLPC_OPENFIRMWARE

         that is used on the OLPC XO-1 Children's Machine. If unsure, say N here.

arch/x86/Kconfig config OLPC_OPENFIRMWARE · line 2078

Quoted 5 lines

arch/x86/Kconfig +5 -0

+config OF
+       def_bool y
+       depends on OLPC_OPENFIRMWARE
+       select OF_PROMTREE
+

This hunk will need to be respun on top of Stephen's CONFIG_OF change.
It's currently in my test-devicetree branch on
git://git.secretlab.ca/git/linux-2.6

Quoted 27 lines

 endif # X86_32

 config K8_NB

(quoted diff) +0 -0

b/arch/x86/include/asm/olpc_prom.h new file mode 100644 index 0000000..96cdcee

arch/x86/include/asm/olpc_prom.h new file +1 -0

@@ -0,0 +1,42 @@
+#include <linux/of.h>  /* linux/of.h gets to determine #include

ordering */ +/*
+ * Definitions for talking to the Open Firmware PROM on
+ * Power Macintosh computers.
+ *
+ * Copyright (C) 1996-2005 Paul Mackerras.
+ *
+ * Updates for PPC64 by Peter Bergner & David Engebretsen, IBM Corp.
+ * Updates for SPARC by David S. Miller
+ * Updates for x86/OLPC by Andres Salomon
+ *
+ * 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.
+ */

arch/x86/include/asm/olpc_prom.h line 23

Quoted 7 lines

arch/x86/include/asm/olpc_prom.h new file +7 -0

+
+#ifndef _X86_PROM_OLPC_H
+#define _X86_PROM_OLPC_H
+#ifdef __KERNEL__
+
+#define OF_ROOT_NODE_ADDR_CELLS_DEFAULT 2
+#define OF_ROOT_NODE_SIZE_CELLS_DEFAULT 1

Do you really need to override these from the default?

arch/x86/include/asm/olpc_prom.h line 27

Quoted 3 lines

arch/x86/include/asm/olpc_prom.h new file +3 -0

+#define of_compat_cmp(s1, s2, l)       strncmp((s1), (s2), (l))
+#define of_prop_cmp(s1, s2)            strcasecmp((s1), (s2))
+#define of_node_cmp(s1, s2)            strcmp((s1), (s2))

Ditto here?

Quoted 20 lines

arch/x86/include/asm/olpc_prom.h new file +6 -0

+extern void prom_build_devicetree(void);
+
+extern void *prom_early_alloc(unsigned long size);
+
+extern char *prom_firstprop(phandle node, char *buf);
+extern char *prom_nextprop(phandle node, const char *prev, char

*buf); +extern int prom_getproplen(phandle node, const char *prop);

arch/x86/include/asm/olpc_prom.h new file +7 -0

+extern int prom_getproperty(phandle node, const char *prop,
+                            char *buffer, int bufsize);
+extern phandle prom_getchild(phandle node);
+extern phandle prom_getsibling(phandle node);
+
+#endif /* __KERNEL__ */
+#endif /* _X86_PROM_OLPC_H */

(quoted diff) +0 -0

b/arch/x86/include/asm/prom.h new file mode 100644 index 0000000..7b561b2

arch/x86/include/asm/prom.h new file +0 -0

arch/x86/include/asm/prom.h line 5

Quoted 6 lines

arch/x86/include/asm/prom.h new file +5 -0

@@ -0,0 +1,5 @@
+#ifdef CONFIG_OLPC_OPENFIRMWARE
+# include <asm/olpc_prom.h>
+#else
+# error "No OFW prom defined for x86!"
+#endif

Personally, I wouldn't bother with the header file redirection.

Quoted 1 line · On Tue, 29 Jun 2010 01:12:36 -0700 Grant Likely…

Hi Andres, comments below....

Thanks!

Quoted 31 lines

Quoted 28 lines · Andres Salomon

Make use of PROC_DEVICETREE to export the tree, and sparc's PROMTREE code to call into OLPC's Open Firmware to build the tree.

(Yes, I know this leaks memory by simply using kmalloc)

Signed-off-by Andres Salomon <[email protected]>

---
 arch/x86/Kconfig                 |    5 ++ arch/x86/include/asm/olpc_prom.h |   42 +++++++++++ arch/x86/include/asm/prom.h      |    5 ++ arch/x86/kernel/Makefile         |    1 + arch/x86/kernel/olpc_ofw.c       |   13 ++++ arch/x86/kernel/olpc_prom.c      |  148 ++++++++++++++++++++++++++++++++++++++ fs/proc/Kconfig |    2 +- 7 files changed, 215 insertions(+), 1 deletions(-) create mode 100644 arch/x86/include/asm/olpc_prom.h create mode 100644 arch/x86/include/asm/prom.h
 create mode 100644 arch/x86/kernel/olpc_prom.c

arch/x86/Kconfig +0 -0

index 71c194d..7aea004 100644
@@ -2071,6 +2071,11 @@ config OLPC_OPENFIRMWARE

         that is used on the OLPC XO-1 Children's Machine. If unsure, say N here.

Quoted 9 lines

arch/x86/Kconfig config OLPC_OPENFIRMWARE · line 2078

Quoted 5 lines

arch/x86/Kconfig +5 -0

+config OF
+       def_bool y
+       depends on OLPC_OPENFIRMWARE
+       select OF_PROMTREE
+

This hunk will need to be respun on top of Stephen's CONFIG_OF change. It's currently in my test-devicetree branch on
git://git.secretlab.ca/git/linux-2.6

Yep, I've changed it locally.

Quoted 37 lines

Quoted 27 lines

 endif # X86_32

 config K8_NB

(quoted diff) +0 -0

b/arch/x86/include/asm/olpc_prom.h new file mode 100644 index 0000000..96cdcee

arch/x86/include/asm/olpc_prom.h new file +1 -0

@@ -0,0 +1,42 @@
+#include <linux/of.h>  /* linux/of.h gets to determine #include

ordering */ +/*
+ * Definitions for talking to the Open Firmware PROM on
+ * Power Macintosh computers.
+ *
+ * Copyright (C) 1996-2005 Paul Mackerras.
+ *
+ * Updates for PPC64 by Peter Bergner & David Engebretsen, IBM Corp.
+ * Updates for SPARC by David S. Miller
+ * Updates for x86/OLPC by Andres Salomon
+ *
+ * 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.
+ */

arch/x86/include/asm/olpc_prom.h line 23

Quoted 7 lines

arch/x86/include/asm/olpc_prom.h new file +7 -0

+
+#ifndef _X86_PROM_OLPC_H
+#define _X86_PROM_OLPC_H
+#ifdef __KERNEL__
+
+#define OF_ROOT_NODE_ADDR_CELLS_DEFAULT 2
+#define OF_ROOT_NODE_SIZE_CELLS_DEFAULT 1

Do you really need to override these from the default?

Quoted 5 lines

arch/x86/include/asm/olpc_prom.h line 27

Quoted 3 lines

arch/x86/include/asm/olpc_prom.h new file +3 -0

+#define of_compat_cmp(s1, s2, l)       strncmp((s1), (s2), (l))
+#define of_prop_cmp(s1, s2)            strcasecmp((s1), (s2))
+#define of_node_cmp(s1, s2)            strcmp((s1), (s2))

Ditto here?

They're based upon what the old promfs patch used.  I need to test and verify that strings are being mangled in the same way before I start making changes here.

Quoted 19 lines

Quoted 19 lines

arch/x86/include/asm/olpc_prom.h new file +6 -0

+extern void prom_build_devicetree(void);
+
+extern void *prom_early_alloc(unsigned long size);
+
+extern char *prom_firstprop(phandle node, char *buf);
+extern char *prom_nextprop(phandle node, const char *prev, char

*buf); +extern int prom_getproplen(phandle node, const char *prop);

arch/x86/include/asm/olpc_prom.h new file +7 -0

+extern int prom_getproperty(phandle node, const char *prop,
+                            char *buffer, int bufsize);
+extern phandle prom_getchild(phandle node);
+extern phandle prom_getsibling(phandle node);
+
+#endif /* __KERNEL__ */
+#endif /* _X86_PROM_OLPC_H */

(quoted diff) +0 -0

b/arch/x86/include/asm/prom.h new file mode 100644 index 0000000..7b561b2

arch/x86/include/asm/prom.h new file +0 -0

Quoted 8 lines

arch/x86/include/asm/prom.h line 5

Quoted 6 lines

arch/x86/include/asm/prom.h new file +5 -0

@@ -0,0 +1,5 @@
+#ifdef CONFIG_OLPC_OPENFIRMWARE
+# include <asm/olpc_prom.h>
+#else
+# error "No OFW prom defined for x86!"
+#endif

Personally, I wouldn't bother with the header file redirection.

The reason for the header file redirection is because this is OLPC-only; the x86 folks don't want me claiming this to be the One True x86 OFW.

Quoted 2 lines · Andres Salomon

On Tue, 29 Jun 2010 01:12:36 -0700
Grant Likely <[email protected]> wrote:

Quoted 29 lines

Quoted 20 lines

Quoted 20 lines

arch/x86/include/asm/olpc_prom.h new file +6 -0

+extern void prom_build_devicetree(void);
+
+extern void *prom_early_alloc(unsigned long size);
+
+extern char *prom_firstprop(phandle node, char *buf);
+extern char *prom_nextprop(phandle node, const char *prev, char

*buf); +extern int prom_getproplen(phandle node, const char *prop); +extern int prom_getproperty(phandle node, const char *prop,
+                            char *buffer, int bufsize);

arch/x86/include/asm/olpc_prom.h new file +5 -0

+extern phandle prom_getchild(phandle node);
+extern phandle prom_getsibling(phandle node);
+
+#endif /* __KERNEL__ */
+#endif /* _X86_PROM_OLPC_H */

(quoted diff) +0 -0

b/arch/x86/include/asm/prom.h new file mode 100644 index 0000000..7b561b2

arch/x86/include/asm/prom.h new file +0 -0

Quoted 8 lines

arch/x86/include/asm/prom.h line 5

Quoted 6 lines

arch/x86/include/asm/prom.h new file +5 -0

@@ -0,0 +1,5 @@
+#ifdef CONFIG_OLPC_OPENFIRMWARE
+# include <asm/olpc_prom.h>
+#else
+# error "No OFW prom defined for x86!"
+#endif

Personally, I wouldn't bother with the header file redirection.

Quoted 3 lines

The reason for the header file redirection is because this is OLPC-only; the x86 folks don't want me claiming this to be the One True x86 OFW.

However, the #ifdef/#elseif/#else/#endif approach also makes the assumption that only one kind of OFW will be supported by any given kernel. Or for that matter, both OFW and the flattened tree also become mutually exclusive due to the default behaviour override.

Besides, aren't the function declarations just the interface defined by the prom extraction code? Is there any need to #ifdef that API? I would think those function prototypes should be defined by the header for the prom extraction code.

We need phandle for some exported sparc headers; of.h isn't an exported header, and it would be silly to export it when all we really need is one or two types from it. So, move the phandle/ihandle definitions into types.h.

include/linux/types.h +0 -0

index 01a082f..26526ea 100644

Quoted 14 lines · Andres Salomon

We need phandle for some exported sparc headers; of.h isn't an exported header, and it would be silly to export it when all we really need is one or two types from it. So, move the phandle/ihandle definitions into types.h.

include/linux/types.h +0 -0

index 01a082f..26526ea 100644
@@ -219,6 +219,10 @@ struct ustat {
 	char			f_fpack[6];
 };
 

include/linux/types.h struct ustat { · line 226

Quoted 5 lines

include/linux/types.h +4 -0

+/* Basic openboot/openfirmware types */
+typedef u32 phandle;
+typedef u32 ihandle;
+
 #endif	/* __KERNEL__ */

The above is inside #ifdef __KERNEL__ / #endif so it is not exported as we drop code protected by __KERNEL__ when we prepare for export.

Id addition "phandle" and "ihandle" needs to have two underscores apended as we cannot just add the above to the userspace namespace and expect it to be OK.

We do this for many other typers already, see __u32 for example.

Sam

Quoted 15 lines · On Mon, 30 Aug 2010 07:06:27 +0200 Sam Ravnborg <[email protected]> wrote:

Quoted 14 lines · Andres Salomon

We need phandle for some exported sparc headers; of.h isn't an exported header, and it would be silly to export it when all we really need is one or two types from it. So, move the phandle/ihandle definitions into types.h.

include/linux/types.h +0 -0

index 01a082f..26526ea 100644
@@ -219,6 +219,10 @@ struct ustat {
 	char			f_fpack[6];
 };
 

Quoted 9 lines

include/linux/types.h struct ustat { · line 226

Quoted 5 lines

include/linux/types.h +4 -0

+/* Basic openboot/openfirmware types */
+typedef u32 phandle;
+typedef u32 ihandle;
+
 #endif	/* __KERNEL__ */

The above is inside #ifdef __KERNEL__ / #endif
so it is not exported as we drop code protected
by __KERNEL__ when we prepare for export.

At least for me, that's fine; I don't need phandle/ihandle to be available to userspace. The folks who work on the userspace fdt code may feel differently, however.

(I'm not sure if you're suggesting it be outside the __KERNEL__ ifdef or not..)