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-rw-r--r--kernel/resource.c61
1 files changed, 58 insertions, 3 deletions
diff --git a/kernel/resource.c b/kernel/resource.c
index e633106b12f6..ca6a1536b205 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -623,7 +623,7 @@ resource_size_t resource_alignment(struct resource *res)
*/
struct resource * __request_region(struct resource *parent,
resource_size_t start, resource_size_t n,
- const char *name)
+ const char *name, int flags)
{
struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
@@ -634,6 +634,7 @@ struct resource * __request_region(struct resource *parent,
res->start = start;
res->end = start + n - 1;
res->flags = IORESOURCE_BUSY;
+ res->flags |= flags;
write_lock(&resource_lock);
@@ -679,7 +680,7 @@ int __check_region(struct resource *parent, resource_size_t start,
{
struct resource * res;
- res = __request_region(parent, start, n, "check-region");
+ res = __request_region(parent, start, n, "check-region", 0);
if (!res)
return -EBUSY;
@@ -776,7 +777,7 @@ struct resource * __devm_request_region(struct device *dev,
dr->start = start;
dr->n = n;
- res = __request_region(parent, start, n, name);
+ res = __request_region(parent, start, n, name, 0);
if (res)
devres_add(dev, dr);
else
@@ -876,3 +877,57 @@ int iomem_map_sanity_check(resource_size_t addr, unsigned long size)
return err;
}
+
+#ifdef CONFIG_STRICT_DEVMEM
+static int strict_iomem_checks = 1;
+#else
+static int strict_iomem_checks;
+#endif
+
+/*
+ * check if an address is reserved in the iomem resource tree
+ * returns 1 if reserved, 0 if not reserved.
+ */
+int iomem_is_exclusive(u64 addr)
+{
+ struct resource *p = &iomem_resource;
+ int err = 0;
+ loff_t l;
+ int size = PAGE_SIZE;
+
+ if (!strict_iomem_checks)
+ return 0;
+
+ addr = addr & PAGE_MASK;
+
+ read_lock(&resource_lock);
+ for (p = p->child; p ; p = r_next(NULL, p, &l)) {
+ /*
+ * We can probably skip the resources without
+ * IORESOURCE_IO attribute?
+ */
+ if (p->start >= addr + size)
+ break;
+ if (p->end < addr)
+ continue;
+ if (p->flags & IORESOURCE_BUSY &&
+ p->flags & IORESOURCE_EXCLUSIVE) {
+ err = 1;
+ break;
+ }
+ }
+ read_unlock(&resource_lock);
+
+ return err;
+}
+
+static int __init strict_iomem(char *str)
+{
+ if (strstr(str, "relaxed"))
+ strict_iomem_checks = 0;
+ if (strstr(str, "strict"))
+ strict_iomem_checks = 1;
+ return 1;
+}
+
+__setup("iomem=", strict_iomem);