[PATCH -v3 2/3] resource: Make alloc_free_mem_region() works for iomem_resource

[Huang Ying <ying.huang@intel.com>]

During developing a kunit test case for region_intersects(), some fake
resources need to be inserted into iomem_resource.  To do that, a
resource hole needs to be found first in iomem_resource.

However, alloc_free_mem_region() cannot work for iomem_resource now.
Because the start address to check cannot be 0 to detect address
wrapping 0 in gfr_continue(), while iomem_resource.start == 0.  To
make alloc_free_mem_region() works for iomem_resource, gfr_start() is
changed to avoid to return 0 even if base->start == 0.  We don't need
to check 0 as start address.

Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Baoquan He <bhe@redhat.com>
---
 kernel/resource.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/resource.c b/kernel/resource.c
index 235dc77f8add..035ef16c1a66 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -1873,7 +1873,7 @@ static resource_size_t gfr_start(struct resource *base, resource_size_t size,
 		return end - size + 1;
 	}
 
-	return ALIGN(base->start, align);
+	return ALIGN(max(base->start, align), align);
 }
 
 static bool gfr_continue(struct resource *base, resource_size_t addr,
-- 
2.39.2