resource: Set type of "reserve=" user-specified resources
When we reserve regions because the user specified a "reserve=" parameter,
set the resource type to either IORESOURCE_IO (for regions below 0x10000)
or IORESOURCE_MEM. The test for 0x10000 is just a heuristic; obviously
there can be memory below 0x10000 as well.
Improve documentation of the "reserve=" parameter.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/kernel/resource.c b/kernel/resource.c
index 54ba6de..ba3252f 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -1478,7 +1478,7 @@ void __devm_release_region(struct device *dev, struct resource *parent,
EXPORT_SYMBOL(__devm_release_region);
/*
- * Called from init/main.c to reserve IO ports.
+ * Reserve I/O ports or memory based on "reserve=" kernel parameter.
*/
#define MAXRESERVE 4
static int __init reserve_setup(char *str)
@@ -1489,26 +1489,38 @@ static int __init reserve_setup(char *str)
for (;;) {
unsigned int io_start, io_num;
int x = reserved;
+ struct resource *parent;
- if (get_option (&str, &io_start) != 2)
+ if (get_option(&str, &io_start) != 2)
break;
- if (get_option (&str, &io_num) == 0)
+ if (get_option(&str, &io_num) == 0)
break;
if (x < MAXRESERVE) {
struct resource *res = reserve + x;
+
+ /*
+ * If the region starts below 0x10000, we assume it's
+ * I/O port space; otherwise assume it's memory.
+ */
+ if (io_start < 0x10000) {
+ res->flags = IORESOURCE_IO;
+ parent = &ioport_resource;
+ } else {
+ res->flags = IORESOURCE_MEM;
+ parent = &iomem_resource;
+ }
res->name = "reserved";
res->start = io_start;
res->end = io_start + io_num - 1;
- res->flags = IORESOURCE_BUSY;
+ res->flags |= IORESOURCE_BUSY;
res->desc = IORES_DESC_NONE;
res->child = NULL;
- if (request_resource(res->start >= 0x10000 ? &iomem_resource : &ioport_resource, res) == 0)
+ if (request_resource(parent, res) == 0)
reserved = x+1;
}
}
return 1;
}
-
__setup("reserve=", reserve_setup);
/*