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-rw-r--r--include/linux/ioport.h4
-rw-r--r--kernel/resource.c16
2 files changed, 18 insertions, 2 deletions
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 26fad187d66..b22790268b6 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -52,6 +52,7 @@ struct resource_list {
#define IORESOURCE_MEM_64 0x00100000
#define IORESOURCE_WINDOW 0x00200000 /* forwarded by bridge */
+#define IORESOURCE_MUXED 0x00400000 /* Resource is software muxed */
#define IORESOURCE_EXCLUSIVE 0x08000000 /* Userland may not map this resource */
#define IORESOURCE_DISABLED 0x10000000
@@ -143,7 +144,8 @@ static inline unsigned long resource_type(const struct resource *res)
}
/* Convenience shorthand with allocation */
-#define request_region(start,n,name) __request_region(&ioport_resource, (start), (n), (name), 0)
+#define request_region(start,n,name) __request_region(&ioport_resource, (start), (n), (name), 0)
+#define request_muxed_region(start,n,name) __request_region(&ioport_resource, (start), (n), (name), IORESOURCE_MUXED)
#define __request_mem_region(start,n,name, excl) __request_region(&iomem_resource, (start), (n), (name), excl)
#define request_mem_region(start,n,name) __request_region(&iomem_resource, (start), (n), (name), 0)
#define request_mem_region_exclusive(start,n,name) \
diff --git a/kernel/resource.c b/kernel/resource.c
index 9c358e26353..7b36976e5de 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -15,6 +15,7 @@
#include <linux/spinlock.h>
#include <linux/fs.h>
#include <linux/proc_fs.h>
+#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/device.h>
#include <linux/pfn.h>
@@ -681,6 +682,8 @@ resource_size_t resource_alignment(struct resource *res)
* release_region releases a matching busy region.
*/
+static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
+
/**
* __request_region - create a new busy resource region
* @parent: parent resource descriptor
@@ -693,6 +696,7 @@ struct resource * __request_region(struct resource *parent,
resource_size_t start, resource_size_t n,
const char *name, int flags)
{
+ DECLARE_WAITQUEUE(wait, current);
struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
if (!res)
@@ -717,7 +721,15 @@ struct resource * __request_region(struct resource *parent,
if (!(conflict->flags & IORESOURCE_BUSY))
continue;
}
-
+ if (conflict->flags & flags & IORESOURCE_MUXED) {
+ add_wait_queue(&muxed_resource_wait, &wait);
+ write_unlock(&resource_lock);
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ schedule();
+ remove_wait_queue(&muxed_resource_wait, &wait);
+ write_lock(&resource_lock);
+ continue;
+ }
/* Uhhuh, that didn't work out.. */
kfree(res);
res = NULL;
@@ -791,6 +803,8 @@ void __release_region(struct resource *parent, resource_size_t start,
break;
*p = res->sibling;
write_unlock(&resource_lock);
+ if (res->flags & IORESOURCE_MUXED)
+ wake_up(&muxed_resource_wait);
kfree(res);
return;
}