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sparc: Add mutex for set property calls.

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On some platforms, the I2C controller is shared between the OS and
OBP.  OBP uses this I2C controller to access the EEPROM, and thus is
programmed when the kernel calls prom_setprop().

Wrap such calls with the new of_set_property_mutex.

Relevant I2C bus drivers can grab this mutex around top-level I2C
operations to provide the proper protection.

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2008-08-19 21:56:35 -07:00
parent 072bd413b8
commit 2481d76615
3 changed files with 14 additions and 0 deletions
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2
arch/sparc/include/asm/prom.h
View File

@ -18,6 +18,7 @@
*/
#include <linux/types.h>
#include <linux/proc_fs.h>
#include <linux/mutex.h>
#include <asm/atomic.h>
#define OF_ROOT_NODE_ADDR_CELLS_DEFAULT 2
@ -73,6 +74,7 @@ struct of_irq_controller {
extern struct device_node *of_find_node_by_cpuid(int cpuid);
extern int of_set_property(struct device_node *node, const char *name, void *val, int len);
extern struct mutex of_set_property_mutex;
extern int of_getintprop_default(struct device_node *np,
const char *name,
int def);

6
arch/sparc/kernel/prom.c
View File

@ -54,6 +54,9 @@ int of_getintprop_default(struct device_node *np, const char *name, int def)
}
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;
@ -77,7 +80,10 @@ int of_set_property(struct device_node *dp, const char *name, void *val, int len
void *old_val = prop->value;
int ret;
mutex_lock(&of_set_property_mutex);
ret = prom_setprop(dp->node, (char *) name, val, len);
mutex_unlock(&of_set_property_mutex);
err = -EINVAL;
if (ret >= 0) {
prop->value = new_val;

6
arch/sparc64/kernel/prom.c
View File

@ -59,6 +59,9 @@ int of_getintprop_default(struct device_node *np, const char *name, int def)
}
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;
@ -82,7 +85,10 @@ int of_set_property(struct device_node *dp, const char *name, void *val, int len
void *old_val = prop->value;
int ret;
mutex_lock(&of_set_property_mutex);
ret = prom_setprop(dp->node, name, val, len);
mutex_unlock(&of_set_property_mutex);
err = -EINVAL;
if (ret >= 0) {
prop->value = new_val;