alistair23-linux/arch/sparc/kernel/prom_common.c
Thomas Gleixner d6d3c4e656 OF: convert devtree lock from rw_lock to raw spinlock
With the locking cleanup in place (from "OF: Fixup resursive
locking code paths"), we can now do the conversion from the
rw_lock to a raw spinlock as required for preempt-rt.

The previous cleanup and this conversion were originally
separate since they predated when mainline got raw spinlock (in
commit c2f21ce2e3 "locking: Implement new raw_spinlock").

So, at that point in time, the cleanup was considered plausible
for mainline, but not this conversion.  In any case, we've kept
them separate as it makes for easier review and better bisection.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[PG: taken from preempt-rt, update subject & add a commit log]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
2013-02-08 17:02:40 -06:00

162 lines
3.5 KiB
C

/* prom_common.c: OF device tree support common 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 davem@davemloft.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/export.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>
#include <asm/oplib.h>
#include "prom.h"
struct device_node *of_console_device;
EXPORT_SYMBOL(of_console_device);
char *of_console_path;
EXPORT_SYMBOL(of_console_path);
char *of_console_options;
EXPORT_SYMBOL(of_console_options);
int of_getintprop_default(struct device_node *np, const char *name, int def)
{
struct property *prop;
int len;
prop = of_find_property(np, name, &len);
if (!prop || len != 4)
return def;
return *(int *) prop->value;
}
EXPORT_SYMBOL(of_getintprop_default);
DEFINE_MUTEX(of_set_property_mutex);
EXPORT_SYMBOL(of_set_property_mutex);
int of_set_property(struct device_node *dp, const char *name, void *val, int len)
{
struct property **prevp;
void *new_val;
int err;
new_val = kmemdup(val, len, GFP_KERNEL);
if (!new_val)
return -ENOMEM;
err = -ENODEV;
mutex_lock(&of_set_property_mutex);
raw_spin_lock(&devtree_lock);
prevp = &dp->properties;
while (*prevp) {
struct property *prop = *prevp;
if (!strcasecmp(prop->name, name)) {
void *old_val = prop->value;
int ret;
ret = prom_setprop(dp->phandle, name, val, len);
err = -EINVAL;
if (ret >= 0) {
prop->value = new_val;
prop->length = len;
if (OF_IS_DYNAMIC(prop))
kfree(old_val);
OF_MARK_DYNAMIC(prop);
err = 0;
}
break;
}
prevp = &(*prevp)->next;
}
raw_spin_unlock(&devtree_lock);
mutex_unlock(&of_set_property_mutex);
/* XXX Upate procfs if necessary... */
return err;
}
EXPORT_SYMBOL(of_set_property);
int of_find_in_proplist(const char *list, const char *match, int len)
{
while (len > 0) {
int l;
if (!strcmp(list, match))
return 1;
l = strlen(list) + 1;
list += l;
len -= l;
}
return 0;
}
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, 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, &prom_sparc_ops);
of_console_init();
pr_info("PROM: Built device tree with %u bytes of memory.\n",
prom_early_allocated);
}