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-rw-r--r--kernel/resource.c96
1 files changed, 42 insertions, 54 deletions
diff --git a/kernel/resource.c b/kernel/resource.c
index 155ec873ea4d..38b8d11c9eaf 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -318,24 +318,27 @@ int release_resource(struct resource *old)
EXPORT_SYMBOL(release_resource);
-/*
- * Finds the lowest iomem resource existing within [res->start..res->end].
- * The caller must specify res->start, res->end, res->flags, and optionally
- * desc. If found, returns 0, res is overwritten, if not found, returns -1.
- * This function walks the whole tree and not just first level children until
- * and unless first_level_children_only is true.
+/**
+ * Finds the lowest iomem resource that covers part of [start..end]. The
+ * caller must specify start, end, flags, and desc (which may be
+ * IORES_DESC_NONE).
+ *
+ * If a resource is found, returns 0 and *res is overwritten with the part
+ * of the resource that's within [start..end]; if none is found, returns
+ * -1.
+ *
+ * This function walks the whole tree and not just first level children
+ * unless @first_level_children_only is true.
*/
-static int find_next_iomem_res(struct resource *res, unsigned long desc,
- bool first_level_children_only)
+static int find_next_iomem_res(resource_size_t start, resource_size_t end,
+ unsigned long flags, unsigned long desc,
+ bool first_level_children_only,
+ struct resource *res)
{
- resource_size_t start, end;
struct resource *p;
bool sibling_only = false;
BUG_ON(!res);
-
- start = res->start;
- end = res->end;
BUG_ON(start >= end);
if (first_level_children_only)
@@ -344,7 +347,7 @@ static int find_next_iomem_res(struct resource *res, unsigned long desc,
read_lock(&resource_lock);
for (p = iomem_resource.child; p; p = next_resource(p, sibling_only)) {
- if ((p->flags & res->flags) != res->flags)
+ if ((p->flags & flags) != flags)
continue;
if ((desc != IORES_DESC_NONE) && (desc != p->desc))
continue;
@@ -359,32 +362,31 @@ static int find_next_iomem_res(struct resource *res, unsigned long desc,
read_unlock(&resource_lock);
if (!p)
return -1;
+
/* copy data */
- if (res->start < p->start)
- res->start = p->start;
- if (res->end > p->end)
- res->end = p->end;
+ res->start = max(start, p->start);
+ res->end = min(end, p->end);
res->flags = p->flags;
res->desc = p->desc;
return 0;
}
-static int __walk_iomem_res_desc(struct resource *res, unsigned long desc,
- bool first_level_children_only,
- void *arg,
+static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
+ unsigned long flags, unsigned long desc,
+ bool first_level_children_only, void *arg,
int (*func)(struct resource *, void *))
{
- u64 orig_end = res->end;
+ struct resource res;
int ret = -1;
- while ((res->start < res->end) &&
- !find_next_iomem_res(res, desc, first_level_children_only)) {
- ret = (*func)(res, arg);
+ while (start < end &&
+ !find_next_iomem_res(start, end, flags, desc,
+ first_level_children_only, &res)) {
+ ret = (*func)(&res, arg);
if (ret)
break;
- res->start = res->end + 1;
- res->end = orig_end;
+ start = res.end + 1;
}
return ret;
@@ -407,13 +409,7 @@ static int __walk_iomem_res_desc(struct resource *res, unsigned long desc,
int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start,
u64 end, void *arg, int (*func)(struct resource *, void *))
{
- struct resource res;
-
- res.start = start;
- res.end = end;
- res.flags = flags;
-
- return __walk_iomem_res_desc(&res, desc, false, arg, func);
+ return __walk_iomem_res_desc(start, end, flags, desc, false, arg, func);
}
EXPORT_SYMBOL_GPL(walk_iomem_res_desc);
@@ -427,13 +423,9 @@ EXPORT_SYMBOL_GPL(walk_iomem_res_desc);
int walk_system_ram_res(u64 start, u64 end, void *arg,
int (*func)(struct resource *, void *))
{
- struct resource res;
+ unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
- res.start = start;
- res.end = end;
- res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
-
- return __walk_iomem_res_desc(&res, IORES_DESC_NONE, true,
+ return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true,
arg, func);
}
@@ -444,13 +436,9 @@ int walk_system_ram_res(u64 start, u64 end, void *arg,
int walk_mem_res(u64 start, u64 end, void *arg,
int (*func)(struct resource *, void *))
{
- struct resource res;
+ unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
- res.start = start;
- res.end = end;
- res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
-
- return __walk_iomem_res_desc(&res, IORES_DESC_NONE, true,
+ return __walk_iomem_res_desc(start, end, flags, IORES_DESC_NONE, true,
arg, func);
}
@@ -464,25 +452,25 @@ int walk_mem_res(u64 start, u64 end, void *arg,
int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
void *arg, int (*func)(unsigned long, unsigned long, void *))
{
+ resource_size_t start, end;
+ unsigned long flags;
struct resource res;
unsigned long pfn, end_pfn;
- u64 orig_end;
int ret = -1;
- res.start = (u64) start_pfn << PAGE_SHIFT;
- res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
- res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
- orig_end = res.end;
- while ((res.start < res.end) &&
- (find_next_iomem_res(&res, IORES_DESC_NONE, true) >= 0)) {
+ start = (u64) start_pfn << PAGE_SHIFT;
+ end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
+ flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
+ while (start < end &&
+ !find_next_iomem_res(start, end, flags, IORES_DESC_NONE,
+ true, &res)) {
pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
end_pfn = (res.end + 1) >> PAGE_SHIFT;
if (end_pfn > pfn)
ret = (*func)(pfn, end_pfn - pfn, arg);
if (ret)
break;
- res.start = res.end + 1;
- res.end = orig_end;
+ start = res.end + 1;
}
return ret;
}