[RESEND PATCH] kernel, resource: use resource_overlaps() to simplify region_intersects()

From: Wei Yang
Date: Tue Mar 05 2019 - 03:35:12 EST


The three checks in region_intersects() is to see whether two resources
overlap. This means it could be simplified with one resource_overlaps().

Also fix two typo in related function.

Signed-off-by: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
Reviewed-by: Like Xu <like.xu@xxxxxxxxxxxxxxx>
Reviewed-by: Yuan Yao <yuan.yao@xxxxxxxxxxxxxxx>
---
kernel/iomem.c | 4 ++--
kernel/resource.c | 11 +++++------
2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/kernel/iomem.c b/kernel/iomem.c
index f7525e14ebc6..93c264444510 100644
--- a/kernel/iomem.c
+++ b/kernel/iomem.c
@@ -55,7 +55,7 @@ static void *try_ram_remap(resource_size_t offset, size_t size,
*
* MEMREMAP_WB - matches the default mapping for System RAM on
* the architecture. This is usually a read-allocate write-back cache.
- * Morever, if MEMREMAP_WB is specified and the requested remap region is RAM
+ * Moreover, if MEMREMAP_WB is specified and the requested remap region is RAM
* memremap() will bypass establishing a new mapping and instead return
* a pointer into the direct map.
*
@@ -86,7 +86,7 @@ void *memremap(resource_size_t offset, size_t size, unsigned long flags)
/* Try all mapping types requested until one returns non-NULL */
if (flags & MEMREMAP_WB) {
/*
- * MEMREMAP_WB is special in that it can be satisifed
+ * MEMREMAP_WB is special in that it can be satisfied
* from the direct map. Some archs depend on the
* capability of memremap() to autodetect cases where
* the requested range is potentially in System RAM.
diff --git a/kernel/resource.c b/kernel/resource.c
index b0fbf685c77a..34dfb94305bb 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -521,21 +521,20 @@ EXPORT_SYMBOL_GPL(page_is_ram);
int region_intersects(resource_size_t start, size_t size, unsigned long flags,
unsigned long desc)
{
- resource_size_t end = start + size - 1;
+ struct resource res;
int type = 0; int other = 0;
struct resource *p;

+ res.start = start;
+ res.end = start + size - 1;
+
read_lock(&resource_lock);
for (p = iomem_resource.child; p ; p = p->sibling) {
bool is_type = (((p->flags & flags) == flags) &&
((desc == IORES_DESC_NONE) ||
(desc == p->desc)));

- if (start >= p->start && start <= p->end)
- is_type ? type++ : other++;
- if (end >= p->start && end <= p->end)
- is_type ? type++ : other++;
- if (p->start >= start && p->end <= end)
+ if (resource_overlaps(p, &res))
is_type ? type++ : other++;
}
read_unlock(&resource_lock);
--
2.19.1