[PATCH 5/9] of: no longer call prom_ functions directly; use an ops structure

Andres Salomon
2010-08-30T03:58:53Z

Rather than assuming an architecture defines prom_getchild and friends,
define an ops struct with hooks for the various prom functions that
pdt.c needs. This ops struct is filled in by the
arch-(and sometimes firmware-)specific code, and passed to
of_pdt_build_devicetree.

Update sparc code to define the ops struct as well.

Signed-off-by: Andres Salomon <dilinger@queued.net>
---
arch/sparc/kernel/prom_common.c | 37 ++++++++++++++++++++++++++++++++++++-
drivers/of/pdt.c | 39 ++++++++++++++++++---------------------
include/linux/of_pdt.h | 20 +++++++++++++++++++-
3 files changed, 73 insertions(+), 23 deletions(-)

diff --git a/arch/sparc/kernel/prom_common.c b/arch/sparc/kernel/prom_common.c
index fe84d56..0972b39 100644
--- a/arch/sparc/kernel/prom_common.c
+++ b/arch/sparc/kernel/prom_common.c
@@ -118,11 +118,46 @@ int of_find_in_proplist(const char *list, const char *match, int len)
}
EXPORT_SYMBOL(of_find_in_proplist);

+/*
+ * SPARC32 and SPARC64's 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_nextprop_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_nextprop(phandle node, const char *prev,
+ char *buf)
+{
+ const char *name;
+
+ buf[0] = '\0';
+ name = prom_nextprop(node, prev, buf);
+ return handle_nextprop_quirks(buf, name);
+}
+
unsigned int prom_early_allocated __initdata;

+static struct of_pdt_ops prom_sparc_ops __initdata = {
+ .nextprop = prom_common_nextprop,
+ .getproplen = prom_getproplen,
+ .getproperty = prom_getproperty,
+ .getchild = prom_getchild,
+ .getsibling = prom_getsibling,
+};
+
void __init prom_build_devicetree(void)
{
- of_pdt_build_devicetree(prom_root_node);
+ of_pdt_build_devicetree(prom_root_node, &prom_sparc_ops);
of_console_init();

pr_info("PROM: Built device tree with %u bytes of memory.\n",
diff --git a/drivers/of/pdt.c b/drivers/of/pdt.c
index f0872b6..fd02fc1 100644
--- a/drivers/of/pdt.c
+++ b/drivers/of/pdt.c
@@ -24,6 +24,8 @@
#include <linux/of_pdt.h>
#include <asm/prom.h>

+static struct of_pdt_ops *of_pdt_prom_ops __initdata;
+
void __initdata (*prom_build_more)(struct device_node *dp,
struct device_node ***nextp);

@@ -58,7 +60,7 @@ static struct property * __init build_one_prop(phandle node, char *prev,
{
static struct property *tmp = NULL;
struct property *p;
- const char *name;
+ int err;

if (tmp) {
p = tmp;
@@ -76,28 +78,20 @@ 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);
- }
-
- if (!name || strlen(name) == 0) {
+ err = of_pdt_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 = of_pdt_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,
- p->length);
+ len = of_pdt_prom_ops->getproperty(node, p->name,
+ p->value, p->length);
if (len <= 0)
p->length = 0;
((unsigned char *)p->value)[p->length] = '\0';
@@ -129,10 +123,10 @@ static char * __init get_one_property(phandle node, const char *name)
char *buf = "<NULL>";
int len;

- len = prom_getproplen(node, name);
+ len = of_pdt_prom_ops->getproplen(node, name);
if (len > 0) {
buf = prom_early_alloc(len);
- len = prom_getproperty(node, name, buf, len);
+ len = of_pdt_prom_ops->getproperty(node, name, buf, len);
}

return buf;
@@ -210,21 +204,25 @@ static struct device_node * __init prom_build_tree(struct device_node *parent,
#endif
dp->full_name = build_full_name(dp);

- dp->child = prom_build_tree(dp, prom_getchild(node), nextp);
+ dp->child = prom_build_tree(dp,
+ of_pdt_prom_ops->getchild(node), nextp);

if (prom_build_more)
prom_build_more(dp, nextp);

- node = prom_getsibling(node);
+ node = of_pdt_prom_ops->getsibling(node);
}

return ret;
}

-void __init of_pdt_build_devicetree(phandle root_node)
+void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
{
struct device_node **nextp;

+ BUG_ON(!ops);
+ of_pdt_prom_ops = ops;
+
allnodes = prom_create_node(root_node, NULL);
#if defined(CONFIG_SPARC)
allnodes->path_component_name = "";
@@ -233,6 +231,5 @@ void __init of_pdt_build_devicetree(phandle root_node)

nextp = &allnodes->allnext;
allnodes->child = prom_build_tree(allnodes,
- prom_getchild(allnodes->phandle),
- &nextp);
+ of_pdt_prom_ops->getchild(allnodes->phandle), &nextp);
}
diff --git a/include/linux/of_pdt.h b/include/linux/of_pdt.h
index c0a8774..7acabff 100644
--- a/include/linux/of_pdt.h
+++ b/include/linux/of_pdt.h
@@ -13,10 +13,28 @@
#ifndef _LINUX_OF_PDT_H
#define _LINUX_OF_PDT_H

+/* overridable operations for calling into the PROM */
+struct of_pdt_ops {
+ /*
+ * buf should be 32 bytes; return 0 on success.
+ * If prev is NULL, the first property will be returned.
+ */
+ 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 *prom_early_alloc(unsigned long size);

/* for building the device tree */
-extern void of_pdt_build_devicetree(phandle root_node);
+extern void of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops);

extern void (*prom_build_more)(struct device_node *dp,
struct device_node ***nextp);
--
1.5.6.5