[PATCH] expand_resource
From: Matthew Wilcox (willy_at_debian.org)
Date: 09/30/03
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Date: Tue, 30 Sep 2003 22:04:10 +0100 To: Linus Torvalds <torvalds@osdl.org>
Rewrite expand_resource() to be racefree and move it to kernel/resource.c.
Index: linux-2.6/kernel/resource.c
===================================================================
RCS file: /var/cvs/linux-2.6/kernel/resource.c,v
retrieving revision 1.3.2.1
retrieving revision 1.4
diff -u -p -r1.3.2.1 -r1.4
--- linux-2.6/kernel/resource.c 28 Sep 2003 02:27:48 -0000 1.3.2.1
+++ linux-2.6/kernel/resource.c 28 Sep 2003 04:06:24 -0000 1.4
@@ -266,6 +268,53 @@ int allocate_resource(struct resource *r
err = -EBUSY;
write_unlock(&resource_lock);
return err;
+}
+
+/*
+ * Expand an existing resource by size amount.
+ */
+int expand_resource(struct resource *res, unsigned long size,
+ unsigned long align)
+{
+ unsigned long start, end;
+
+ /* see if we can expand above */
+ end = (res->end + size + align - 1) & ~(align - 1);
+
+ write_lock(&resource_lock);
+ if (res->sibling) {
+ if (res->sibling->start > end)
+ goto end;
+ } else {
+ if (res->parent->end >= end)
+ goto end;
+ }
+
+ /* now try below */
+ start = ((res->start - size + align) & ~(align - 1)) - align;
+
+ if (res->parent->child == res) {
+ if (res->start <= start)
+ goto start;
+ } else {
+ struct resource *prev = res->parent->child;
+ while (prev->sibling != res)
+ prev = prev->sibling;
+ if (prev->end < start)
+ goto start;
+ }
+
+ write_unlock(&resource_lock);
+ return -ENOMEM;
+
+ start:
+ res->start = start;
+ write_unlock(&resource_lock);
+ return 0;
+ end:
+ res->end = end;
+ write_unlock(&resource_lock);
+ return 0;
}
/*
Index: linux-2.6/drivers/parisc/ccio-dma.c
===================================================================
RCS file: /var/cvs/linux-2.6/drivers/parisc/ccio-dma.c,v
retrieving revision 1.7.2.1
retrieving revision 1.7
diff -u -p -r1.7.2.1 -r1.7
--- linux-2.6/drivers/parisc/ccio-dma.c 28 Sep 2003 02:27:09 -0000 1.7.2.1
+++ linux-2.6/drivers/parisc/ccio-dma.c 27 Sep 2003 20:03:16 -0000 1.7
@@ -1534,42 +1534,6 @@ static void __init ccio_init_resources(s
(unsigned long)&ioc->ioc_hpa->io_io_low_hv);
}
-static int expand_resource(struct resource *res, unsigned long size,
- unsigned long align)
-{
- struct resource *temp_res;
- unsigned long start = res->start;
- unsigned long end ;
-
- /* see if we can expand above */
- end = (res->end + size + align - 1) & ~(align - 1);;
-
- temp_res = __request_region(res->parent, res->end, end - res->end,
- "expansion");
- if(!temp_res) {
- /* now try below */
- start = ((res->start - size + align) & ~(align - 1)) - align;
- end = res->end;
- temp_res = __request_region(res->parent, start, size,
- "expansion");
- if(!temp_res) {
- return -ENOMEM;
- }
- }
- release_resource(temp_res);
- temp_res = res->parent;
- release_resource(res);
- res->start = start;
- res->end = end;
-
- /* This could be caused by some sort of race. Basically, if
- * this tripped something stole the region we just reserved
- * and then released to check for expansion */
- BUG_ON(request_resource(temp_res, res) != 0);
-
- return 0;
-}
-
static void expand_ioc_area(struct resource *parent, struct ioc *ioc,
unsigned long size, unsigned long min,
unsigned long max, unsigned long align)
Index: linux-2.6/include/linux/ioport.h
===================================================================
RCS file: /var/cvs/linux-2.6/include/linux/ioport.h,v
retrieving revision 1.2.2.1
retrieving revision 1.2
diff -u -p -r1.2.2.1 -r1.2
--- linux-2.6/include/linux/ioport.h 28 Sep 2003 02:27:45 -0000 1.2.2.1
+++ linux-2.6/include/linux/ioport.h 27 Sep 2003 20:03:18 -0000 1.2
@@ -97,6 +97,8 @@ extern int allocate_resource(struct reso
void (*alignf)(void *, struct resource *,
unsigned long, unsigned long),
void *alignf_data);
+int expand_resource(struct resource *res, unsigned long size,
+ unsigned long align);
/* Convenience shorthand with allocation */
#define request_region(start,n,name) __request_region(&ioport_resource, (start), (n), (name))
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- Previous message: Henrik Christian Grove: "Re: Radeon framebuffer problems i 2.6.0-test6"
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